Gate assembly for a railroad hopper car

Information

  • Patent Grant
  • 6412422
  • Patent Number
    6,412,422
  • Date Filed
    Friday, April 6, 2001
    23 years ago
  • Date Issued
    Tuesday, July 2, 2002
    22 years ago
Abstract
A gate assembly for a railroad hopper car is disclosed. The gate assembly includes a frame defining a discharge opening, a slidable door mounted on the frame for movement between a closed position, wherein the door closes the discharge opening, and an open position, wherein the door is positioned to allow commodity to pass through the discharge opening. Either of two modular components can be arranged in combination with the door on the gate assembly to allow the gate assembly to be conditioned for either pneumatic and/or gravitational discharge or gravitational discharge only of commodity from the gate assembly. A drive mechanism including an apparatus for selectively engaging either the door or either of the modular elements arranged in association with the door is mounted on the frame of the gate assembly, with the apparatus of the drive mechanism preferably being lost motion connected to the door. Seal structure is provided in combination with the frame, door and a modular element for inhibiting debris from contaminating the door and a discharge plenum defined by the frame of the gate assembly.
Description




FIELD OF THE INVENTION




The present invention generally relates to gate assemblies which are adapted for use in combination with railroad hopper cars and through which lading, such as finely comminuted or granulated food grade commodities are discharged and, more specifically, to a gate assembly having interchangeable modular components allowing the gate assembly to be easily and readily conditioned for either pneumatic discharge or sanitized gravitational discharge of lading from the hopper car and through the gate assembly.




BACKGROUND OF THE INVENTION




Railroad hopper cars typically include an underframe for supporting a walled enclosure in which lading is held and transported. As is conventional, the underframe of the car is supported toward opposite ends by well known wheeled trucks which ride on tracks or rails. The bottom of the walled enclosure is usually provided with two or more individual discharge openings for allowing the lading to be discharged from the walled enclosure. The walled enclosure furthermore typically includes sloped or slanted walls or sheets extending upwardly from a periphery of each opening to promote gravitational movement of the lading toward the opening.




Various methods and devices are known in the art for individually closing the discharge openings in the walled enclosure. Basically, such closure devices or gate assemblies are divisible into two categories. Some hopper cars utilize a sliding door or valve type system for selectively opening and closing the openings at the bottom of the walled enclosure. Alternatively, some hopper cars are provided with pneumatically enabled discharge systems which rely on a pressure differential system for exhausting particulate matter or lading from the enclosure of the hopper car.




A conventional slide gate system includes a frame which is bolted or otherwise secured to the hopper car. The frame likewise defines a discharge opening arranged in registry with the opening at the bottom of the slanting walls on the hopper car. A gate or door is arranged on the frame for sliding movement along a generally horizontal path of travel between open and closed positions relative to the discharge opening on the frame of the gate assembly. A door operating mechanism including one or more racks, typically secured or attached to the door, and rotatably driven pinions is typically used to slide the door between open and closed positions. In an open position, the door of the gate assembly permits the contents of the hopper car enclosure to pass gravitationally from the walled enclosure and through the discharge opening defined by the gate assembly. In a closed position, the door extends across the discharge opening on the frame to shut off the material or matter flow through the gate assembly.




A conventional pneumatic discharge system for hopper cars involves connecting a discharge assembly including a panike housing beneath each opening in the bottom of the hopper car. A pneumatic discharge conduit extends from at least one of the sides the pan-like housing in a direction generally normal to a longitudinal axis of the car. One end of the pneumatic conduit opens to the interior of the pan-like housing while an opposite end is adapted for connection to a suction hose or the like for conducting the lading held and stored within the walled enclosure to any suitable discharge station.




The transportation and unloading of finely divided materials, and particularly food stuffs, such as sugar, flour and the like within and from the walled enclosure of the hopper car exacerbates the problems involved with the design and engineering of a railroad hopper car discharge gate assembly. When the lading to be transported involves food stuffs, the FDA has promulgated certain rules and regulations which must be met in order for the hopper car to qualify for transporting food stuffs. Of course, one of the paramount concerns involves designing the hopper car discharge gate assembly such that no foreign matter, accumulation of moisture, or insect infiltration is permitted to contact and possibly contaminate the food stuffs even while they are being discharged or unloaded from the railway hopper car.




Sliding gate closure systems have proven adequate over the years. There are, however, problems inherent with these designs. It is common practice to load a hopper car through roof hatches. The lading, when initially introduced into the walled enclosure, is mixed with air and is very fluid. After standing and as the car travels, however, the lading loses the air film from the finely divided particles and the lading settles and becomes very compact.




As mentioned, the discharge gate assembly is mounted at the bottom of the walled enclosure and, in sliding gate systems, the door must be slidably moved against the friction imposed thereon by the load. Known slide gate systems for hopper cars have relatively large doors to effect discharge of the lading in a timely and efficient manner. Once the door has begun movement, it can be moved through its path of travel with a reasonable amount of torque or input to the door operating mechanism. At the onset of door travel toward an open position, however, such sliding gate systems require a relatively high initial opening force to be imparted to the door.




In those hopper cars which transport food stuffs and utilize a sliding gate for controlling the discharge of lading from the walled enclosure of the hopper car, the frame of the gate assembly is usually equipped with a flanged skirt depending from and arranged in surrounding relation relative to the discharge opening defined by the frame of the gate assembly. The flanged skirt defines a discharge plenum. Typically, an air sled or other form of unloading apparatus is clamped to the flanges on the sldrt during a discharge operation thereby permitting the food stuffs in the enclosure of the hopper car to be discharged directly and protectively into the sled and, thus, conveyed away from the hopper car. To inhibit debris, insects, moisture, clay and other forms of debris from contaminating the underside of the door and interior of the discharge plenum during transport of the hopper car, such sliding gate systems typically include a sanitary plate or cover plate which slides between open and closed positions in a horizontal plane generally parallel to the door to close the discharge plenum and protect the underside of the door during transport of the hopper car. Of course, known sanitary plates or cover plates are neither designed nor configured to withstand the load which can be placed thereon by the commodity in the enclosure of the hopper car.




Another problem has been identified with sliding gate systems when the lading in the walled enclosure involves fine granular food stuffs. As will be appreciated, to enable the sliding door to operate between positions, an operating gap or opening must be provided between the frame of the gate assembly and the door. Such gap or opening is typically provided between the skirt on the frame and the door. It is through this opening that contaminants, moisture, and related debris can enter the discharge plenum, thus, contaminating the food stuffs upon discharge of the lading from the hopper car and through the discharge plenum.




Arranging seals or gaskets about the discharge opening of the gate assembly frame in an attempt to close or seal such openings has often resulted in the seal or gasket being pulled from the gate assembly. The racks on the door coupled with the sliding movement of the door between open and closed positions further complicate.the ability to seal the door against contaminants passing into the discharge plenum or opening on the frame of the gate assembly. Moreover, the required need to seal an element of the gate assembly movable in opposite linear directions furthermore complicates the sealing ability of the gate assembly.




It is known in the art to mount a pan-like structure or housing including the pneumatic discharge conduit to the frame of the gate assembly beneath the sliding door. The pan-like structure or housing is typically fastened to the walled enclosure of the hopper car beneath the sliding door with a plurality of fasteners. As such, the hopper car can function in either a gravitational discharge mode or a pneumatic discharge mode. Of course, valuable time is consumed and lost by affixing and removing the pan-like housing from the hopper car depending upon which type of discharge operation is required or desired. Mounting and arranging the pan-like structure or element above the sliding door of the gate assembly has been found to obstruct the flow of material from the walled enclosure in a gravitational mode of material discharge.




Moreover, it is desirable to provide only a single drive mechanism for operating the components of the gate assembly thereby simplifying its operation.




Thus, there remains a need and a desire for a gate assembly for a railroad hopper car which can be conditioned for either pneumatic or gravitational discharge of lading from the walled enclosure of the hopper car and which utilizes but a single operating mechanism for operating the components of the gate assembly in timed relation relative to each other. Moreover, it is desirable to provide a gate assembly for a railroad car having a sliding door and wherein the operating mechanism imparts a high impactual opening force against the door during initial stages of its movement toward an open position. Additionally, there is a need and desire for a gate assembly for a railroad hopper car including modular components permitting the gate assembly to be easily and readily conditioned for pneumatic and/or gravitational discharge or gravitational discharge only simply by interchanging the components thereof.




SUMMARY OF THE INVENTION




In view of the above, one of the salient features of the present invention involves the provision of a railroad car discharge gate assembly which can be easily and readily conditioned for either pneumatic and/or gravitational discharge or gravitational discharge only of materials therethrough. As is conventional, the gate assembly of the present invention includes a rigid frame preferably having a rectangular configuration and defining a generally centralized discharge opening. Moreover, the gate assembly of the present invention is provided with a door or first element slidable on the frame along a predetermined path of travel extending across the discharge opening. Unlike other known railroad car discharge gates, however, the present invention allows for either of two interchangeable modular components or elements to be easily and readily mounted on the frame for sliding movement along a predetermined path of travel beneath the door and across the discharge opening. One modular element is configured as an open top pan assembly including a pneumatic port allowing for pneumatic discharge of materials. The other modular component of the present invention is preferably configured as a flat plate for inhibiting debris from contaminating an underside of the gate and unloading attachment areas. Accordingly, a primary object of this invention is to provide a gate assembly specifically designed to allow for either pneumatic and/or gravitational discharge or gravitational discharge only of materials therethrough.




A unique drive mechanism forms part of the gate assembly of the present invention. According to the present invention, the drive mechanism is selectively engagable with and capable of selectively moving either the door or the modular element arranged on the gate assembly in combination with the door toward an open position and relative to the frame of the gate assembly. As is conventional, the drive mechanism includes an operating shaft assembly supported on the frame for rotation about a fixed axis.




The drive mechanism of the present invention farther includes a rack and pinion assembly arranged in combination with the operating shaft assembly. The rack and pinion assembly includes a pair of laterally spaced pinions arranged on and rotatable with the operating shaft assembly. The rack and pinion assembly further includes a pair of laterally spaced racks or toothed tracks arranged in intermeshing relation relative to the pinions. Each of the racks are carried on the frame of the gate assembly preferably on opposed sides of the door and in slidable relation relative to the door and either of the interchangeable modular components. In a preferred form, the racks are spaced from the frame so as to reduce the coefficient of friction therebetween. In a most preferred form, ultra-high molecular weight polyethylene is disposed between the frame of the gate assembly and each of the racks to promote sliding movements of the racks relative to the frame of the gate assembly.




In a preferred form, the drive mechanism flirther includes an apparatus arranged in operative combination with the rack and pinion assembly for selectively coupling either the door or the modular component or both to the drive mechanism. The apparatus includes a control rod preferably mounted for endwise movement and having an actuator arranged thereon for operably engaging either the door or the modular component arranged on the gate assembly. In a preferred form, the actuator is positioned in the path of movement of either the door or the modular component arranged in combination with the door such that when the drive mechanism is operated, either the door or modular component will be moved toward an open position in response to rotation of the operating shaft. Alternatively, in a most preferred form, the rack and pinion assembly is locked thereby inhibiting rotation of the operating shaft assembly, thus, preventing movement of either the door or the modular element arranged in combination with the door on the gate assembly.




Moreover, the apparatus of the drive mechanism is preferably provided with a detent mechanism for releasably holding the actuator in a selected position to operably engage either the door or the modular component arranged in combination on the gate assembly. The apparatus of the drive mechanism furthermore preferably includes a spring for resiliently urging the control rod and the actuator carried thereby toward a predetermined position. In a preferred form, cam structure is arranged in combination with the apparatus for automatically positioning the control rod and thereby the actuator relative to the frame of the gate assembly when the apparatus is positioned adjacent an end wall of the frame of the gate assembly.




Another salient feature of the present invention involves providing a lost motion connection between the drive mechanism and the door of the gate assembly. Rotation of the operating shaft assembly initially results in sliding movement of only the racks without corresponding linear movement of the door. Notably, only the racks slidably move relative to the frame and the door during the collapse of the lost motion connection. Because only the racks move, the operating shaft assembly will have a predetermined range of free rotation. Upon collapse of the lost motion connection, a relatively high impactual opening force will be applied to the door thereby enhancing opening of the door. Upon collapse of the lost motion continued rotation of the operating shaft assembly will effect substantially simultaneous linear movement of the rack and door relative to the frame. Moreover, and besides offering a relatively high impactual opening force to the door, the lost motion connection between the door and the operating shaft maintains the door and the other modular element arranged in combination with the door in timed relation relative to each other.




In a preferred form, a tamper seal can be provided in combination with the operating shaft assembly. The purpose of the tamper seal is to provide a visual indication of whether the operating shaft assembly has been operated to move either the door or that modular component arranged on the gate assembly in combination with the door toward an open position.




The seal structure is preferably comprised of an elongated and hollow elastomeric member configured for energization regardless of the direction of movement of either the door or the modular component associated with the door. The elastomeric member of the seal structure has a first radial surface arranged in tangential engaging relation relative to a flat surface on the door or the modular component associated with the door thereby allowing the door or the modular component to move in either linear direction while maintaining a sealing engagement therewith. The radial surface preferably has an elongated rib projecting therefrom and extending therealong to enhance the sealing ability of the seal structure relative to either the door or the modular component associated with the door.




In a most preferred form, the elastomeric member of the seal structure has a centralized mounting portion with an aperture or opening defining an axis extending generally parallel to the path of travel of the door. The first radial surface on the elastomeric member is disposed to one side of the axis. In an alternative form, the elastomeric member has a second radial surface disposed on an opposite side of the seal structure. The second radial surface is disposed generally tangential to a flat surface on the door or the modular component associated with the door thereby allowing the door or the modular component to move in either linear direction while maintaining a sealing engagement therewith. As will be appreciated, two sealing surfaces allows the seal to be compressed between the door and the modular component thereby acting as a compression/wiper seal or allowing for reversal of the seal structure thereby prolonging the useful life thereof.




In a preferred form, the frame of the gate assembly furthermore includes wall structure or skirt arranged in surrounding relation relative to and depending from the discharge opening of the frame to define a discharge plenum through which material passes. To facilitate connection of a discharge apparatus thereto, the lower end of the depending walled structure or skirt is configured with flanges which operate in a conventional manner with an inlet to the unloading apparatus thereby enhancing transference of particulate materials through the gate assembly and into the discharge apparatus. As will be appreciated, when the modular component arranged in combination with the door on the gate assembly is configured as a flat or sanitary plate, such plate inhibits debris from contaminating the underside of the door and the plenum chamber.




When the gate assembly of the present invention is mounted to a hopper car, it allows the gate assembly to be readily and easily conditioned for either gravitational or pneumatic discharge of food grade materials from an enclosure on the car wherein the food grade materials are held and transported. Either of two modular components are fitted to the gate assembly and move along rails projecting outwardly from the frame. During operation, the apparatus of the drive mechanism is suitably conditioned to properly position the actuator of the apparatus in the path of travel of movable elements on the gate assembly thereby effecting their movement when the operating shaft assembly is rotated. The lost motion connection of the drive mechanism allows a relatively high impactual force to be imparted to the door during the initial opening thereof. Moreover, the seal structure preferably forming a part of the present invention inhibits debris from passing between the elements and the frame thereby protecting the food grade commodity from contamination.




These and other objects, aims and advantages of the present invention will be readily and quickly appreciated from the following detailed description, appended claims, and drawings.











DETAILED DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side view of a railroad hopper car equipped with a gate assembly embodying principles of the present invention;





FIG. 1A

is an enlarged side elevational view of a gate assembly according to the present invention;





FIG. 2

is a top view of a gate assembly according to the present invention, with parts broken away to illustrate particular features of the present invention;





FIG. 3

is an end elevational view of the gate assembly illustrated in

FIG. 2

;





FIG. 4

is a perspective view of a door element used in combination with the gate assembly of the present invention;





FIG. 5

is a perspective view of an open top pan modular element usable in combination with the gate assembly of the present invention;





FIG. 6

is a partial perspective view of a modular plate element usable in combination with the gate assembly of the present invention;





FIG. 7

is a perspective view of the gate assembly of the present invention illustrating the door in a closed position and the modular pan element arranged in association with the gate assembly;





FIG. 8

is an enlarged fragmentary side elevational view of the gate assembly;





FIG. 9

is a sectional view taken along line


9





9


of

FIG. 8

;





FIG. 10

is a sectional view taken along line


10





10


of

FIG. 2

;





FIG. 11

is a perspective view of an apparatus forming part of a drive mechanism of the gate assembly of the present invention in a first condition;





FIG. 11A

is a perspective view similar to

FIG. 11

but illustrating the apparatus of the drive mechanism in a second condition;





FIG. 11B

is a perspective view similar to

FIG. 11

but illustrating the apparatus of the drive mechanism in a third condition;





FIG. 12

is a fragmentary and enlarged top plan view of the apparatus of the drive mechanism illustrated in the first condition;





FIG. 13

is an enlarged end view of a fragmentary portion of the apparatus of the drive mechanism illustrated in

FIG. 12

;





FIG. 14

is a schematic representation of the relative position of various components of the apparatus of the drive mechanism and door when the apparatus is arranged in different conditions;





FIG. 15

is a sschematic representation of the relative position of various components of the apparatus of the drive mechanism and pan element when the apparatus is arranged in different conditions;





FIG. 16

is a shematic end elevational view of the various components illustrated in

FIG. 15

;





FIG. 17

is a schematic representation of the relative position of various components of the apparatus of machanism, door and sanitary plate when the apparatus is arranged in different conditions, with the door being schematically illustrated in phantom lines;





FIG. 18

is an enlarged side elevational view of a tamper seal arranged in operative combination with a portion of the drive mechanism;





FIG. 19

is a sectional view taken along line


19





19


of

FIG. 2

;





FIG. 20

is an enlarged longitudinal sectional view of a seal used in combination with the present invention; and





FIG. 21

is a sectional view taken along line


21





21


of FIG.


3


.











DETAILED DESCRIPTION OF THE PRESENT INVENTION




While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described in detail a preferred embodiment of the invention with the understanding the present disclosure is to be considered as setting forth an exemplification of the invention which is not intended to limit the invention to the specific embodiment illustrated.




Referring now to the drawings, wherein like reference numerals indicate like parts throughout the several views, a railroad hopper car, equipped with a gate assembly according to the present invention, is illustrated in FIG.


1


. The railroad hopper car, generally designated by reference numeral


10


, includes a multiwalled enclosure


12


for storing and transporting commodity therewithin. As is known in the art, the multiwalled enclosure


12


is supported on an underframe


14


. The underframe


14


extends generally the length of the car


10


. As is typical, the underframe


14


is supported toward opposite ends thereof by conventional wheeled trucks, generally designated by reference numeral


18


.




As illustrated, a bottom


20


of the enclosure


12


is provided with a plurality of openings


22


for allowing the commodity to be discharged from the enclosure


12


. As will be appreciated, more or fewer openings than that shown can be readily provided without detracting or departing from the true spirit and scope of the present invention. As shown, the enclosure


12


of hopper car


10


includes a plurality of slope sheets


24


funneling downwardly toward each opening


22


in the bottom


20


of the hopper car


10


to promote the discharge of commodity therefrom.




A gate assembly, generally designated by reference numeral


30


, is shown arranged in combination with each opening


22


along the bottom


20


of the hopper car


10


. Since the gate assemblies


30


arranged along the bottom


20


of the car


10


are substantially identical relative to each other, only one gate assembly will be described in detail. As illustrated in

FIGS. 2 and 3

, each gate assembly


30


includes a rigid frame


32


defining a discharge opening


34


. The frame


32


of gate assembly


30


is preferably fabricated from FDA approved materials in all commodity contact areas to allow the hopper car


10


to hold and transport food grade materials and eliminate lining requirements. Notably, when the gate assembly


30


is attached or otherwise connected to the walled enclosure


12


, the discharge opening


34


defined by the frame


32


is arranged in registry with a respective opening


22


(

FIG. 1

) in the walled enclosure


12


of the hopper car


10


.




As shown, frame


32


includes opposed and generally parallel side walls


36


,


38


extending lengthwise of the hopper car and opposed end walls


40


and


42


extending transversely across the hopper car. In the illustrated form of the invention, the disposition of the side walls


36


,


38


and end walls


40


,


42


is such that a trapezoidal or rectangular shape is provided for the discharge opening


34


.




As shown in

FIGS. 1A

,


2


,


3


and


8


, each side wall


36


,


38


and end wall


40


,


42


has a mounting flange


44


formed toward an upper end thereof In a manner well known in the art, the flanges


44


, toward the upper end of the walls


36


through


42


, are configured to mate with respective portions of the hopper car to facilitate attachment of the gate assembly


30


to the hopper car. In one form, the flanges


44


define spaced holes


46


(

FIGS. 2 and 8

) allowing for passage of suitable fasteners, such as threaded bolts, therethrough.




The gate assembly


30


of the present invention is furthermore provided with a door or first element


50


mounted on the frame


32


for selectively closing the discharge opening


34


defined by frame


32


. The door


50


is mounted for sliding movement along a predetermined path of travel. In the illustrated form of the invention, and in a closed position (shown in solid lines in FIG.


2


), the door


50


extends across the discharge opening


34


defined by the frame


32


. As will be appreciated, however, door


50


is movable to an open position (shown in phantom lines in

FIG. 1A

) to allow commodity to pass from the gate assembly


30


through the discharge opening


34


. Frame


32


is preferably provided with parallel frame extensions or supports


52


and


53


(

FIG. 2

) extending lengthwise of the hopper car and away from the end wall


42


of frame


32


. The frame extensions or supports


52


,


53


support peripheral and opposed sides of the door


50


when the door


50


is moved to and open position relative to the frame


32


.




As shown in

FIG. 4

, the door


50


is preferably configured as a rigid flat plate


54


including upper and lower surfaces


55


and


56


, respectively. In the illustrated form of the invention, door


50


has a generally rectangular configuration. To permit the gate assembly


30


to be used in combination with a food grade commodity, the door


50


is preferably fabricated from an FDA approved material such as stainless steel.




The side walls


36


,


38


and end walls


40


,


42


of the gate assembly


32


are each provided with a ledge


47


which underlies and supports the door


50


. In a preferred form, and as shown in

FIGS. 9 and 10

, and to prevent galling of stainless steel in contact with stainless steel, an upper door contacting surface on each ledge


47


is covered with ultra-high molecular weight polyethylene


48


material. The provision of the material


48


between the ledge


47


and the undersurface


56


of the door


50


acts as a shield between the lower or underside


56


of the door


50


and the frame


32


of the gate assembly


30


while also serving to reduce the coefficient of friction therebetween when the door


50


is slidably moved relative to the frame


32


.




The side walls


36


,


38


and end walls


40


,


42


of the frame


32


of gate assembly


30


depend from the discharge opening


34


to define a plenum chamber


57


(FIGS.


9


and


10


). As is conventional, the lower ends of walls


36


through


42


of gate assembly


30


have a flange-like configuration


58


to permit a conventional discharge apparatus


59


(schematically illustrated in phantom lines in

FIG. 9

) to be coupled or otherwise secured thereto. Suffice it to say, the discharge apparatus


59


(also commonly referred to as an air sled) maybe of the type disclosed in one or more of the following U.S. Pat. Nos. 2,376,814; 2,517,837; 2, 527,455, 2,527,466; 2,589,968; 2, 657,100; 2,675,274; 2, 681,748, 2,789,739. Alternatively, the discharge apparatus


59


may be a simple compression boot or chamber that draws particulate matter or commodity toward to a storage reservoir.




Gate assembly


30


furthermore includes either of two modular elements


60


,


80


to be arranged in operable association with the door


50


. Either element


60


,


80


is configured to be interchangeably and slidably arranged on the frame


32


of gate assembly


30


in vertically spaced relation relative to door


50


. In the illustrated embodiment of the invention, modular element


60


is configured as an open top pan assembly and element


80


is preferably configured as a sanitary plate or cover. Both interchangeable elements


60


and


80


are preferably fabricated from FDA approved materials such as stainless steel or the like whereby permitting the gate assembly


30


to be used in conjunction with food grade commodities.




The open top pan assembly


60


is used in combination with the gate assembly


30


for pneumatically discharging lading from the enclosure


12


(

FIG. 1

) of the hopper car


10


. As shown in

FIG. 5

, the open top pan assembly


60


preferably comprises two generally vertical and laterally spaced side walls


62


, two slanting end walls


64


rigidly joined to the side walls


62


, and a generally flat bottom


66


. As shown in

FIG. 9

, the upper edges of the side walls


62


are bent outwardly to form flanges


68


which terminate in open sided channels


70


. The open sided channels


70


are arranged in combination with rails


71


projecting outwardly from and extending parallel to the side walls


36


,


38


of the frame


32


of the gate assembly


30


for allowing fore-and-aft sliding movement of element


60


along a predetermined path of travel relative to frame


32


between open and closed positions beneath the door


50


.




To enhance sliding movement of the pan assembly


60


relative to the frame


32


of the gate assembly


30


, and to effectively seal the sides of the pan assembly


60


to the frame


32


thereby inhibiting passage of debris therepast, ultra-high molecular weight polyethylene material


73


is preferably disposed between the rails


71


and the open sided channels


70


on the pan assembly


60


. In the illustrated embodiment, and as shown in

FIG. 5

, the upper edges of the end walls


64


are likewise bent to project in a fore-and-aft direction to form flanges


72


. In a preferred form, the flanges


72


projecting fore-and-aft from the end walls


64


of the pan assembly


60


are generally coplanar with the flanges


68


and extend generally parallel to and in vertically spaced relationship with the flanged configuration


56


at the bottom of the walls


36


through


42


on the frame


32


of the gate assembly


30


(FIGS.


19


and


21


).




Returning to

FIG. 5

, a conduit system, within the open top pan assembly


60


, is provided for the pneumatic discharge of commodity from the enclosure


12


. As shown, the conduit system is in the form of a centrally disposed inverted and generally V-shape hood


74


which, in a preferred form of the invention, is hingedly connected to the flat bottom


66


of the pan assembly


60


between the side walls


62


and above the flat bottom


66


so as to define, with the bottom


66


, a conduit extending transversely across the pan assembly


60


between the side walls


62


. An elongated opening or passage


76


is provided between a lower edge of the hood


74


and the bottom


66


of the pan assembly


60


to provide for passage of the commodity from the pan assembly


60


into the conduit whereafter low pressure air will draw or carry the commodity in a conventional manner for discharge of same from the pan assembly


60


. As will be appreciated by those skilled in the art, each side wall


62


of the pan assembly defines an opening


77


which cooperates with the conduit for allowing passage of commodity from the pan assembly


60


. A conventional external conduit


78


is exteriorly connected to each side wall


62


of the pan assembly in surrounding relation relative to the opening or passage


77


. An outer end of the external conduit


78


is adapted to be connected to a conventional pneumatic system in a conventional way. Alternatively, the free end of the external conduit


78


is provided with a conventional cap


79


(

FIG. 7

) releasably secured thereon in a well known manner to seal the open top pan assembly


60


when the hopper car


10


(

FIG. 1

) is in transport.




The second interchangeable or modular element


80


has a generally flat planar configuration between opposed side edges thereof. Like modular element


60


, and as illustrated in

FIG. 6

, the flat sanitary plate


80


is provided with two open sided channels


84


which operate in combination with the rails


71


on the frame


32


of the gate assembly for allowing the modular element


80


to slidably move in a fore-and -aft direction along a predetermined path of travel relative to the frame


32


between open and closed positions beneath the door


50


. As will be described in further detail below, the purpose of the modular element


80


is to inhibit debris and the like from contaminating the underside


56


of the door


50


and the plenum chamber


57


during transport of the hopper car


10


. Notably, the ultra-high molecular weight material


73


is likewise used between the rails


71


and the channels


84


on the second element or plate


80


to seal the sides of the plate


80


and frame


32


against debris moving therebetween.




Turning now to

FIG. 7

, gate assembly


30


further includes an actuating or drive mechanism


88


carried on the frame


32


. One of the many salient features of the present invention relates to the ability of the drive mechanism


88


to be selectively engaged with and capable of moving either the door


50


or either of the two modular elements


60


,


80


arranged in association with the door


50


relative to the frame


32


and toward an open position. In the illustrated embodiment, the drive mechanism


88


is designed to linearly displace the door


50


and the second modular element


60


,


80


arranged on the gate assembly


30


in association with the door


50


different linear distances. In the illustrated embodiment, drive mechanism


88


is designed to linearly displace the second modular element


60


,


80


arranged on the gate assembly


32


in combination with the door


50


a greater linear distance than the door


50


linearly moves. As illustrated in

FIG. 2

, drive mechanism


88


preferably includes an operating shaft assembly


90


carried on the frame


32


for rotation about a fixed axis


92


. The operating shaft assembly


90


includes an elongated operating shaft


94


rotatably mounted for fixed rotation about axis


92


and capstans or operating handles


96


affixed to opposite ends of shaft


94


.




Drive mechanism


88


further includes a rack and pinion assembly


100


arranged in operative combination with the operating shaft assembly


90


. As illustrated in

FIG. 2

, the rack and pinion assembly


100


preferably includes a pair of laterally spaced pinions


102


and


104


mounted on and for rotation with the operating shaft


94


of the operating shaft assembly


90


. The pinions


102


and


104


are arranged in intermeshing relation with a pair of elongated racks or toothed tracks


106


and


108


.




As illustrated in

FIG. 2

, the toothed tracks


106


,


108


are carried on the frame


32


of the gate assembly


30


and extend generally parallel to opposed sides of the door


50


. Notably, the elongated racks


106


,


108


are mounted on the frame


32


in laterally outward spaced relation from opposed side edges of the door


50


for endwise sliding movement relative to the frame


32


, the door


50


, and either of the two modular elements


60


,


80


mounted on the frame


32


in operative association with the door


50


. Lateral or sideways movement of the racks


106


,


108


is limited by guides


110


(

FIGS. 8

,


9


and


10


) affixed to the frame


32


on opposite lateral sides of each rack


106


,


108


.




As illustrated in

FIGS. 8

,


9


and


10


, each rack


106


,


108


of the rack and pinion assembly


100


is vertically spaced from the frame


32


of the gate assembly


30


on which it is mounted and relative to which it slidably moves. Because the racks


106


,


108


are separated from the frame


32


, the coefficient of friction between the racks


106


,


108


and frame


32


is substantially reduced. Several alternative devices could be used to separate the racks


106


,


108


from the frame


32


of the gate assembly


30


. In the illustrated embodiment, ultra-high molecular weight polyethylene material


112


is entrapped between the racks


106


,


108


and the frame


32


of the gate assembly


30


thereby reducing the coefficient of friction therebetween, thus, enhancing sliding movement of the racks


106


,


108


relative to the frame


32


.




The drive mechanism


88


of the gate assembly


30


further includes an apparatus


116


for selectively interconnecting the operating shaft assembly


90


to either the door


50


or the modular component


60


,


80


arranged in combination on the gate assembly


30


. Turning to

FIG. 11

, apparatus


116


is arranged in combination and moves with the racks


106


,


108


of the rack and pinions assembly


100


. As illustrated, apparatus


116


includes a laterally extending base


118


which spans the distance between and is rigidly joined to the free ends of the racks


106


,


108


of the rack and pinion assembly


100


. In the illustrated form of the invention, the apparatus


116


is manually operated. It is well within the spirit and scope of the present invention, however, and with slight redesign efforts, the indexing system or apparatus


116


can include a driver for replacing the manual efforts now contemplated for use in conjunction therewith.




As shown in

FIG. 11

, apparatus


116


includes a control rod


120


mounted on the base


118


preferably by a pair of laterally spaced supports


121


and


123


for generally linear displacement along an axis


122


extending generally parallel with the end wall


42


of the frame


32


(FIG.


7


). As shown, the control rod


120


is preferably provided with handles


124


and


126


arranged toward opposite ends thereof for easy grasp by an operator and which readily allow the control rod


120


to be linearly positioned relative to the frame


32


and rotated about axis


122


. In the illustrated form, the control rod


122


has a pair of laterally spaced actuators


128


and


130


arranged for conjoint linear displacement with but which are inhibited from rotating with the control rod


122


. In the illustrated form, the actuators


128


and


130


move endwise within laterally elongated slots


132


and


134


defined by the base


118


of apparatus


116


. For reasons discussed in detail hereinafter, the control rod


120


of apparatus


116


is resiliently biased relative to the frame


32


of the gate assembly


30


. In the illustrated form, a spring


136


resiliently biases the control rod


120


and the actuators


128


and


130


carried thereon to the right, as seen in

FIG. 11

, and to a predetermined position or condition.




In a preferred form, apparatus


116


can be selectively conditioned in any of three positions or conditions. First, the apparatus


116


can be conditioned in a position (

FIG. 11B

) whereby actuation of the drive mechanism


90


will result in displacement of the door


50


. Second, the apparatus


116


can be conditioned in a position (

FIG. 11A

) whereby actuation of the drive mechanism


90


will result in displacement of the second or modular element


60


,


80


arranged on the gate assembly


30


. Alternatively, the apparatus


116


can be conditioned in a position (

FIG. 11

) whereby the drive mechanism


90


is inhibited from imparting movement to and thereby locking both the door


50


and the second element


60


,


80


against displacement relative to the frame


32


of the gate assembly


30


.




Preferably, apparatus


116


further includes a detent mechanism


140


for releasably holding the apparatus


116


in a selected condition. More specifically, the detent mechanism


140


serves to releasably hold the control rod


120


and, thus, the actuators


128


and


130


in a selected condition or position relative to the frame


32


of the gate assembly


30


. As will be appreciated by those skilled in the art, the detent mechanism


140


can take a myriad of different forms from that shown without detracting or departing from the true spirit and scope of the invention. In the form illustrated in

FIG. 11

, the detent mechanism


140


preferably includes a pair of laterally spaced holders


142


,


144


.




In the illustrated embodiment, the holders


142


and


144


are substantially similar. Accordingly, only holder


142


will be described in detail. As shown in

FIGS. 12 and 13

, each holder of the detent mechanism


140


includes an upstanding member


146


carried on the base


118


of the apparatus


116


and a detent


148


carried on and movable with the shaft or control rod


120


. Member


146


of each holder


140


has two laterally spaced notches or reliefs


150


and


152


formed thereon which are representative of two different conditions or positions of the apparatus


116


. In the particular embodiment illustrated, each upstruck member


146


of detent mechanism


140


is configured to limit rotational movement of the respective detent


148


and thereby the control rod


120


about axis


122


. Each notch or relief


150


,


152


is configured to releasably accommodate a portion of the detent


148


carried in the control rod


120


therewithin. As will, be appreciated by those skilled in the art, the resilient action of the spring


136


urges the detents


148


in a sideways or lateral direction furthermore facilitating operation of the detent mechanism


140


by holding the detent


148


within the selected relief or recess


150


,


152


of the detent mechanism


140


and thereby maintaining the actuators


128


,


130


of the apparatus


116


in a selected position relative to the frame


32


of the gate assembly


30


.




The drive mechanism


88


for the gate assembly


30


is lost motion connected to the door


50


through the apparatus


116


. The lost motion connection can take many different forms. Suffice it to say, the lost motion connection allows the operating shaft assembly


90


of gate assembly


30


a predetermined amount or degree of free initial rotation before the door


50


begins to move toward an open position and relative to frame


32


.




As shown in

FIG. 4

, the door


50


is provided with a pair of laterally spaced latches


160


and


162


. As will be appreciated from an understanding of the present invention, the number of latches on the door


50


will correspond to the number of actuators provided in combination with the apparatus


116


of drive mechanism


88


. As shown, the latches


160


,


162


project in a fore-and-aft direction from and beyond a laterally extending edge of the door


50


. Since the latches


160


,


162


are substantially similar to each other only latch


160


will be described in detail.




As shown in

FIGS. 4 and 14

, each latch


160


,


162


is formed from a rigid material such as steel or the like and has sufficient strength.such that when a pulling or pushing force is applied thereto, the latch


160


,


162


will be able to withstand such forces applied thereto without any detrimental change to the configuration of the latch


160


,


162


. Toward the terminal end thereof, each latch


160


,


162


is provided with a hook-like configuration


164


defining an actuator engaging surface


166


. Each latch


160


,


162


is furthermore provided with another actuator engaging surface


168


disposed in spaced fore-and-aft direction and closer to the edge of the door


50


than is surface


166


.




When the door


50


is in a closed position relative to the discharge opening


34


, and apparatus


116


of drive mechanism


88


is conditioned in a locked condition or position, the actuators


128


,


130


of the apparatus


116


are in a position as schematically illustrated in solid lines in FIG.


14


. If the operator desires to move the door


50


toward an open position relative to the frame


32


of the gate assembly


30


, the operator would initially position the apparatus


116


in a condition to open the door


50


.




Conditioning the apparatus


116


to open the door


50


is easily and readily effected by the operator positioning the control rod


120


and, thus, the actuators


128


,


130


carried by the control rod


120


in the predetermined path of movement of the door


50


. With the present invention, placing the actuators


128


,


130


in the path of travel of the door


50


involves positioning the actuators


128


,


130


relative to the latches


160


,


162


on the door


50


. Linear displacement of the control rod


120


to open the door


50


results in the actuators


128


,


130


being linearly displaced to the position schematically illustrated in phantom lines in FIG.


14


. Once the operator linearly positions the control rod


120


and actuators


128


,


130


of the apparatus


116


to open the door


50


, the control rod


120


is preferably rotated about axis


122


to a position illustrated in

FIG. 11B

such that the detent mechanism


140


thereafter releasably holds the apparatus


116


in the position or condition selected by the operator.




Once the apparatus


116


has been conditioned to move the door


50


toward an open position, the operator can thereafter impart rotational movements to the operating shaft assembly


90


. Rotational movements imparted to the operating shaft assembly


90


cause linear displacement of the rack and pinion assembly


100


. More specifically, rotation of the operating shaft assembly


90


causes the racks


106


,


108


to linearly move or slide relative to the frame


32


and relative to door


50


. Of course, the direction of linear displacement of the racks


106


,


108


is determined by the rotational direction of the operating shaft assembly


90


. During initial rotation of the operating shaft assembly


90


in a direction to open the door


50


, the racks


106


,


108


slidably move in a direction whereby the racks progressively move in a linear fore-and-aft direction away from the end wall


42


of frame


32


.




As the racks


106


,


108


of the rack and pinion assembly


100


are driven away from the frame


32


, the apparatus


116


of the drive mechanism


90


moves conjointly therewith. Accordingly, the control rod


120


and actuators


128


,


130


carried thereby move with the apparatus


116


and the racks


106


,


108


in response to rotation of the operator shaft assembly


92


. Notably, linear movement of the racks


106


,


108


of the drive mechanism


88


results in displacement of the actuators


128


,


130


from the phantom line position to the dashed line position illustrated in

FIG. 14

whereat the actuators


128


,


130


are positioned to engage the actuator engaging surface


166


on each latch


160


,


162


of the door


50


. It is important to note, however, as the actuators


128


,


130


move from the phantom line position to the dashed line position in response to initial rotation of the operating shaft assembly


90


no linear movement of the door


50


is effected. No linear movement of the door


50


is effected until the actuators


128


,


130


are in engagement with the actuator engaging surface


166


on a latch


160


,


162


associated with the door


50


. Once the actuators


128


,


130


engage the actuator engaging surface


166


on the latch


160


,


162


further linear movement of the actuators


128


,


130


caused by rotation of the operating shaft assembly


90


will cause linear displacement of the door


50


toward an open position. Thus, the drive mechanism


88


advantageously provides lost motion in connection with rotation of the operating shaft assembly


90


and movement of the door


50


toward an open position.




To move the door


50


toward a closed position, the apparatus


116


is conditioned to position the actuators


128


,


130


in the path of travel of the door


50


. In the illustrated embodiment, positioning the actuators


128


,


130


for engagement with the actuator engaging surface


168


on either latch


160


,


162


will suffice for effecting movement of the door


50


toward a closed position. Thereafter, the operating shaft assembly


90


is rotated in a direction opposite from the opening direction. As such, the rotation of the operating shaft assembly


90


will effect linear retraction of the racks


106


,


108


, thus, causing movement of the apparatus


116


toward the end wall


42


of the frame


32


of gate assembly


30


. Movement of the apparatus


116


toward the end wall


42


of the frame


32


of gate assembly will cause the actuators


128


,


130


of apparatus


116


to abut and engage the actuator engaging surface


168


defined by each latch


160


,


162


. As will be appreciated, further rotation of the operating shaft assembly


90


will cause further displacement of apparatus


116


and the actuators


128


,


130


toward the end wall


42


of the frame


32


of gate assembly


30


, thus, ultimately closing the door


50


relative to the discharge opening


34


and the frame


32


of the gate assembly


30


.




Alternatively, the apparatus


116


of the drive mechanism


88


can be selectively conditioned to operably engage and position only the open top pan assembly or second modular element


60


relative to the frame


32


of the gate assembly


30


. Movement of only the top pan assembly or second modular element


60


toward an open position is likewise effected by positioning the actuators


128


,


130


of the apparatus


116


into the path of travel of the top pan assembly


60


and thereafter rotating the operating shaft assembly


90


to enable the apparatus


116


and, thus, move the pan assembly


60


.




Returning to

FIGS. 3 and 5

, in the illustrated form of the invention, the open top pan assembly or modular element


60


, is provided with a pair of laterally spaced fore-and-aft extending arms


170


,


172


projecting from that end of the pan assembly


60


adjacent the end wall


42


of frame


32


when the pan assembly


60


is in a closed position relative to the discharge opening


34


. The arms


170


,


172


extending from the pan assembly


60


are substantially identical and, therefore, only arm


170


will be described in detail.




As schematically represented in

FIGS. 15 and 16

, each arm


170


,


172


of pan assembly


60


is preferably formed as a rigid material tube having sufficient strength such that when a pulling or pushing force is applied thereto the tube


170


,


172


will withstand such forces applied thereto without any detrimental change to the configuration of the tube. Preferably, the tubes have hollow cross-sectional configurations to reduce the overall weight of the gate assembly


30


. Toward a free end thereof, each arm


170


,


172


is provided with laterally spaced actuator engaging surfaces


176


and


178


preferably disposed to opposite sides of the longitudinal axis of each arm


170


,


172


. Moreover, and as illustrated in

FIG. 15

, the actuator engaging surfaces


176


,


178


on each arm


170


,


172


are also spaced apart in a fore-and-aft direction by a distance generally equal to or slightly greater than the thickness of the actuators


128


,


130


of apparatus


116


.




Notably, the actuator engaging surfaces


176


,


178


on the arms


170


,


172


of pan assembly


60


are laterally spaced from the actuator engaging surfaces


166


,


168


on the latches


160


,


162


of door


50


. Accordingly, linear positioning of the control rod


120


of apparatus


116


will effect opening movement of only the door


50


or the pan assembly


60


but not both depending on the disposition or conditioning of the apparatus


116


.




When the pan assembly


60


is in a closed position relative to the discharge opening


34


on the frame


32


of the gate assembly


30


, and apparatus


116


of drive mechanism


90


is conditioned in a locked condition or position, the actuators


128


,


130


of apparatus


116


are in a position as schematically represented in solid lines in

FIGS. 15 and 16

. If the operator desires to move the pan assembly


60


toward an open position relative to the frame


32


of the gate assembly


30


, the operator would position the apparatus


116


in a condition (

FIG. 11A

) to open the pan assembly


60


.




With the present invention, conditioning the apparatus


116


to open the pan assembly


60


is easily and readily effected by the operator positioning the control rod


120


and, thus, the actuators


128


,


130


carried by the control rod


120


in the predetermined path of travel of the pan assembly


60


. Placing the actuators


128


,


130


of the apparatus


116


in the path of travel of the pan assembly


60


involves positioning the actuators


128


,


130


relative to the actuator engaging surface


178


of each arm


170


,


172


on the pan assembly


60


. As will be appreciated from an understanding of the present invention, linear displacement of the control rod


120


of apparatus


116


to the position illustrated in

FIG. 11A

results in the actuators


128


,


130


of apparatus


116


being linearly displaced to the position schematically represented in phantom lines in FIG.


15


. Once the operator positions the control rod


120


and actuators


128


,


130


of the apparatus


116


to open the pan assembly


60


, the control rod


120


is preferably rotated about the axis


122


of rod


120


such that the detent mechanism


140


thereafter releasably holds the apparatus


116


in the position or condition selected by the operator.




Once the apparatus


116


has been conditioned to move the pan assembly


60


toward an open position and relative to the frame


32


of the gate assembly


30


, the operator can thereafter impart rotational movement to the operating shaft assembly


90


in a direction to open the pan assembly


60


. Rotational movements imparted to the operating shaft assembly


90


cause fore-and-aft linear displacement of the racks


106


,


108


of the rack and pinion assembly


100


. More specifically, rotation of the operating shaft assembly


90


causes the racks


106


,


108


to linearly move or slide relative to the frame


32


. Of course, the direction of linear movement of the racks


106


,


108


is determined by the rotational direction of the operating shaft assembly


90


. During initial rotation of the operating shaft assembly


90


in a direction to open the pan assembly, the racks


106


,


108


slidably move in a direction whereby the racks


106


,


108


progressively move in a linear fore-and-aft direction away from the end wall


42


of frame


32


.




As the racks


106


,


108


of the rack and pinion assembly


100


are driven away from the frame


32


, the apparatus


116


of the drive mechanism


88


moves conjointly therewith. Accordingly, the control rod


120


and the actuators


128


,


130


carried thereby move with the apparatus


116


and the racks


106


,


108


in response to rotation of the operating shaft assembly


90


. Notably, linear movement of the racks


106


,


108


of the drive mechanism


88


results in displacement of the actuators


128


,


130


away from the end wall


42


of the frame


32


of gate assembly


30


and into engagement with the actuator engaging surface


178


of each arm


170


,


172


. Once the actuators


128


,


130


are engaged with the surface


178


on the arms


170


,


172


further linear movement of the actuators


128


,


130


away from the end wall


42


of the gate assembly


30


caused by rotation of the operator shaft assembly


90


will cause linear movement of the pan assembly


60


toward an open position relative to the frame


32


of the gate assembly


30


.




With this form of the invention, and as mentioned above, the fore-and-aft spacing between actuator engaging surfaces


176


,


178


on the arms


170


,


172


of the pan assembly


60


is equal to the width of the actuators


128


,


130


of the apparatus


116


of drive mechanism


88


. Accordingly, the actuators


128


,


130


are free to pass between the actuator engaging surfaces


176


,


178


without requiring or effecting linear displacement of the pan assembly


60


. Because the distance between the actuator engaging surfaces


176


,


178


of each arm


170


,


172


is generally equal to or slightly greater than the width of each actuator


128


,


130


of apparatus


116


, movement of the pan assembly


60


will be effected upon initial rotation of the operating shaft assembly


90


. As such, the pan assembly


60


will travel a greater linear distance between open and closed positions than does the door


50


between open and closed positions.




To move the pan assembly


60


toward a closed position, the apparatus


116


is conditioned to position the actuators


128


,


130


in the path of travel of the pan assembly


60


. In the illustrated embodiment, positioning the actuators


128


,


130


for engagement with the actuator engaging surface


176


on the arms


170


,


172


of the pan assembly


60


requires release of the apparatus


116


from its engagement with the holder


140


thereby allowing the spring


136


to return the actuators


128


,


130


to the solid line position illustrated in

FIGS. 15 and 16

. Thereafter, the operating shaft assembly


90


is rotated in a direction opposite from the opening direction. As such, the rotation of the operating shaft assembly


90


will effect linear retraction of the racks


106


,


108


and, thus, causing movement of the apparatus


116


toward the end wall


42


of the frame


32


of gate assembly


30


. The movement of the apparatus


116


toward the end wall


42


of the frame


32


of gate assembly will cause the actuators


128


,


130


of apparatus


116


to abut and engage the actuator engaging surface


176


defined on each arm


170


,


172


. As will be appreciated, further rotation of the operating shaft assembly


92


will cause further displacement of apparatus


116


and the actuators


128


,


130


toward the end wall


42


of the frame


32


of gate assembly


30


, thus, ultimately closing the pan assembly


60


relative to the discharge opening


34


and the frame


32


of the gate assembly


30


.




Special concerns are presented when the gate assembly


30


is conditioned for use with the other modular element or flat plate


80


. As will be appreciated by those skilled in the art, the flat sanitary plate


80


is specifically designed to inhibit debris from contaminating the underside


56


of the door


50


and the plenum chamber


57


. The sanitary plate


80


, however, is neither configured nor designed to withstand the full weight of the commodity within the enclosure


12


thereon. Accordingly, an important design concern involves movement of the sanitary plate


80


in timed relation relative to movement of the door


50


relative to the frame


32


of the gate assembly


30


. Movement of the sanitary plate


80


in timed relation relative to movement of the door


50


toward an open position is again effected by conditioning the apparatus


116


of the drive mechanism


90


to accomplish the desired result.




Returning to

FIG. 6

, the modular element or sanitary plate


80


is preferably provided with a pair of laterally spaced fore-and-aft extending arms


180


,


182


projecting away from that end of plate


80


adjacent the end wall


42


of frame


32


when the second modular element


80


is in a closed position relative to the discharge opening


34


. The arms


180


,


182


extending from the plate


80


are substantially identical relative to each other and, therefore, only arm


180


will be described in detail.




As schematically represented in

FIG. 17

, each arm


180


,


182


is preferably formed as a rigid material tube having sufficient strength such that when a pulling or pushing force is applied thereto the tube


180


,


182


will withstand such forces applied thereto without any detrimental change to the configuration of the tube. Preferably, the tubes


180


,


182


each have hollow cross-sectional configurations to reduce the overall weight of the gate assembly


30


. Toward a free end thereof, each arm


180


,


182


is provided with a laterally elongated actuator engaging surface


186


. Moreover, and as illustrated in

FIG. 17

, each arm


180


,


182


of the second modular element


60


includes an actuator engaging surface


188


spaced apart in a fore-and-aft direction from actuator engaging surface


186


.




The fore-and-aft spacing between the actuator engaging surfaces


186


,


188


on each arm


180


,


182


of the plate or second modular element


60


is equal to the width of the actuators


128


,


130


of the apparatus


116


of drive mechanism


88


. Accordingly, the actuators


128


,


130


of apparatus


116


are free to pass between the actuator engaging surfaces


186


,


188


without requiring or effecting linear displacement of the plate


80


. Because the distance between the actuator engaging surfaces


186


,


188


on each arm


180


,


182


is generally equal to or slightly greater than the width of each actuator


128


,


130


of apparatus


116


, movement of the plate


80


will be effected upon initial rotation of the operating shaft assembly


90


. As such, the plate or second modular element


80


will travel a greater linear distance between open and closed positions than does the door


50


between open and closed positions upon actuation of the operating shaft assembly


90


. Moreover, this design permits substantially immediate movements of the lower element


60


,


80


to overcome the associated static friction forces applied thereto.




When the plate or second modular element


80


is in a closed position relative to the discharge opening


34


on the frame


32


of the gate assembly


30


, and apparatus


116


of drive mechanism


88


is conditioned in a locked condition or position, the actuators


128


,


130


of apparatus


116


are in a position as schematically represented in solid lines in FIG.


17


. The vertical elongation of the actuator engaging surface


178


assures the sanitary plate or second modular element


80


will conjointly open along with and in advance of opening of the door


50


. As such, concerns about the commodity in the enclosure


12


of the hopper car


10


placing a substantial load on the sanitary plate


80


are eliminated.




With the present invention, conditioning the apparatus


116


to open the plate


80


is easily and readily effected by the operator positioning the control rod


120


and, thus, the actuators


128


,


130


carried by the control rod


120


in the predetermined path of travel of the plate


80


. Placing the actuators


128


,


130


of the apparatus


116


in the path of travel of the plate


80


involves positioning the actuators


128


,


130


relative to the actuator engaging surfaces


186


,


188


on the pan assembly


60


. Linear displacement of the control rod


120


of apparatus results in the actuators


128


,


130


being linearly displaced to the position schematically represented in phantom lines in FIG.


17


. Once the operator positions the control rod


120


and actuators


128


,


130


of the apparatus


116


to open the plate


80


, the control rod


120


is preferably rotated about the axis


122


of rod


120


such that the detent mechanism


140


thereafter releasably holds the apparatus


116


in the position or condition selected by the operator.




Once the apparatus


116


has been conditioned to move the plate


80


toward an open position and relative to the frame


32


of the gate assembly


30


, the operator can thereafter impart rotational movement to the operating shaft assembly


90


in a direction to open the plate


80


. As will be appreciated from an understanding of the present invention, rotational movements imparted to the operating shaft assembly


90


cause linear displacement of the rack and pinion assembly


100


. More specifically, rotation of the operating shaft assembly


90


causes the racks


106


,


108


to linearly move or slide relative to the frame


32


. Of course, the direction of linear movement of the racks


106


,


108


is determined by the rotational direction of the operating shaft assembly


90


. During initial rotation of the operating shaft assembly


90


in a direction to open the plate


80


, the racks


106


,


108


of rack and pinion assembly


100


are slidably displaced relative to the door


50


and the frame


32


of the gate assembly


30


.




As the racks


106


,


108


of the rack and pinion assembly


100


are driven away from the frame


32


, the apparatus


116


of the drive mechanism


88


moves conjointly therewith. Accordingly, the control rod


120


and the actuators


128


,


130


carried thereby move with the apparatus


116


and the racks


106


,


108


in response to rotation of the operating shaft assembly


90


. Notably, linear movement of the racks


106


,


108


of the drive mechanism


88


results in displacement of the actuators


128


,


130


away from the end wall


42


of the frame


32


of gate assembly


30


and into pressing or intimate engagement with the actuator engaging surface


186


associated with the plate


80


. Once the actuators


128


,


130


are engaged with the surface


186


on the arms


180


,


182


further movement of the actuators


128


,


130


away from the end wall


42


of the gate assembly


30


caused by rotation of the operator shaft assembly


90


will cause linear movement of the plate


80


toward an open position relative to the frame


32


of the gate assembly


30


.




To move the plate


80


toward a closed position, the apparatus


116


is conditioned to position the actuators


128


,


130


in the path of travel of the plate


80


. In the illustrated embodiment, positioning the actuators


128


,


130


of the apparatus


116


for engagement with the actuator engaging surface


188


on the arms


180


,


182


of the plate


80


will suffice for effecting movement of the plate


80


toward a closed position. Thereafter, the operating shaft assembly


90


is rotated in a direction opposite from the opening direction. As such, the rotation of the operating shaft assembly


90


will effect linear retraction of the racks


106


,


108


and, thus, causing movement of the apparatus


116


toward the end wall


42


of the frame


32


of gate assembly


30


. The movement of the apparatus


116


toward the end wall


42


of the frame


32


of gate assembly


30


will cause the actuators


128


,


130


of apparatus


116


to abut and engage the actuator engaging surface


188


defined on each arm


180


,


182


. As will be appreciated, further rotation of the operating shaft assembly


90


will cause further displacement of apparatus


116


and the actuators


128


,


130


toward the end wall


42


of the frame


32


of gate assembly


30


, thus, ultimately closing the plate


80


relative to the discharge opening


34


and the frame


32


of the gate assembly


30


.




Turning to

FIG. 18

, when the apparatus


116


is returned to a position adjacent the end wall


42


of the gate assembly


30


, the apparatus


116


is automatically returned to a locked condition. In the illustrated form, cam structure


190


is provided for positively locking the apparatus


116


relative to the frame


32


of the gate assembly


30


when the apparatus


116


is returned to a position adjacent the end wall


42


of the frame


32


. In the illustrated form, the cam structure


190


includes an actuating member or cam


192


arranged on each capstan


96


of the operating shaft assembly


90


and a cam follower


194


radially projecting outwardly from control rod


120


and into the path of movement of a respective cam


192


when the apparatus


116


is returned to a position adjacent the end wall


42


of the frame


32


. When the operating shaft assembly


90


is rotated to return the apparatus


116


adjacent the end wall of the frame


32


, the rotating cam


192


positively engages the cam follower


194


thereby displacing the members


148


of the detent mechanism


140


and, thus, rotating the control rod


120


about axis


122


so as to permit the spring


136


(

FIG. 11

) to resiliently bias the detents


148


into a locked position relative to the frame


32


of the gate assembly


30


.




The apparatus


116


furthermore serves to inhibit inadvertent displacement of the door


50


or the modular element


60


,


80


. As illustrated in

FIG. 12

, when the apparatus


116


is in locked condition, each detent


148


of the detent mechanism


140


is removably constrained within an upstruck channel


200


provided on the frame


32


of the gate assembly


30


. Accordingly, if rotational movement is imparted to the operating shaft assembly


90


, the inability of the detents


148


of apparatus


116


to be removed from the channel


200


inhibits linear displacement of the racks


106


,


108


of the rack and pinion assembly


100


thus locking the door


50


and the second modular element


60


,


80


arranged on the gate assembly


30


against linear displacement relative to the frame


32


of the gate assembly


30


. Other alternative locking arrangements for inhibiting linear displacement of the door


50


, element


60


,


80


, and apparatus


116


would equally suffice without detracting or departing from the spirit and cope of the present invention.




In a preferred form, a front end portion or side of the upstruck channel


200


is defined by cam structure


202


preferably projecting away from and angularly disposed relative to the end wall


42


of the frame


32


. An opposite end portion or side of the upstruck channel


200


is defined by bracket structure


203


provided on the frame


32


of the gate assembly


10


. The cam structure


202


preferably comprises a pair of preferably identical laterally spaced cams


204


and


206


(

FIG. 2

) disposed for engagement by the free ends of the detents


148


of the detent mechanism


140


when the apparatus


116


is returned to a position adjacent the end wall


42


of the frame


32


.




To return the door


50


and element


60


,


80


to a closed position relative to the discharge opening


34


of the frame


32


, the apparatus


116


is conditioned to the position illustrated in FIG.


11


. In this position, the detents


148


of the detent mechanism


140


are disengaged from their respective holders


146


and spring


136


urges the detents


148


to the position illustrated in FIG.


11


. As the apparatus


116


is returned to a closed or locked condition, the purpose of the cams


204


,


206


is to engage the free ends of the detents


148


of the detent mechanism


140


and thereby urge the control rod


120


in a linear direction against the action of spring


136


. Notably, each cam


204


,


206


terminates at and opens to the upright channel


200


. As such, and after the detents


148


of the detent mechanism


140


pass over the cams


204


,


206


they are automatically urged into a locked condition relative to the frame


32


by the spring


136


, thus, placing the apparatus


116


in a locked condition.




As shown in

FIG. 18

, a railcar seal


210


can be arranged in combination with the apparatus


116


for visually indicating whether the drive mechanism


88


has been operated to move either the door


50


or the modular element


60


,


80


arranged on the gate assembly


30


toward an open position. As illustrated in

FIG. 18

, each cam


192


of cam structure


190


is provided with a through slot or opening


212


having a closed margin. Moreover, each cam follower


194


on the cam structure


190


defines an aperture or opening


214


having a closed margin. The railcar seal


210


preferably comprises a ribbon-like band


216


which passes through the opening


212


on the cam


192


and the aperture or opening


214


on the cam follower


194


, with opposite ends of the band


216


being secured to each other to provide a visual indication of railcar tampering. As will be appreciated by those skilled in the art, the band


216


is fabricated from a material which can withstand normal forces applied thereto but which will fail when a rotational force is imparted to the drive mechanism


88


to open the door


50


or the modular element


60


,


80


mounted on the gate assembly


30


.




Another salient feature or aspect of the present invention relates to seal structure


220


for inhibiting debris and insect infiltration between the frame


32


, door


50


and the second modular element


60


,


80


arranged on the gate assembly


30


of the present invention. As shown in

FIG. 19

, a portion of the seal structure


220


involves providing a seal


222


transversely across a lateral edge or portion of the second modular component


60


,


80


between the tracks


106


,


108


of the rack and pinion assembly


100


(

FIG. 2

) in sealing engagement with the flange-like configuration


58


at the lower end of the end wall


40


of frame


32


of gate assembly


30


thereby sealing the gate assembly


30


across that end thereof. In the illustrated form of the invention, seal


222


is supported by a depending flange


223


provided on the second modular element


60


,


80


. A suitable fastener


225


, such as a threaded bolt and nut, can be used to releasably fasten the seal


222


to the flange


223


.




Seal


222


is preferably formed as an elongated and hollow elastomeric member


224


configured for energization regardless of the direction of movement of the gate assembly component with which the seal


222


is arranged in operable combination. Moreover, seal


22


allows horizontal discontinuities of either the door


50


or the modular element


60


,


80


such that the seal


22


will automatically re-energize through either open or close direction manipulation of the components horizontal discontinuity removal. As illustrated in

FIG. 20

, seal


222


includes an elongated and preferably extruded member


224


preferably including a mounting portion


226


defining an axis


228


extending generally parallel to the predetermined path of travel of the door


50


. Because the commodity transported and held within the enclosure


12


of hopper car


10


can constitute food grade material, member


224


used to fabricate the seal


222


is of the type approved by the FDA and conforms to the FDA Food Contact Requirements. In a most preferred form, member


224


is formed from a clean grade santoprene of proper hardness. Preferably, member


224


has a hardness ranging between about


70


and about


76


Shore A hardness.




In the illustrated embodiment, a first radial surface


230


is disposed to one side of the mounting portion


226


of member


224


for allowing relative movement of the surface arranged in sealing relationship therewith in either linear direction relative thereto. As shown, the first radial surface


230


of seal


222


is preferably arranged in tangential engaging relation relative to the flat surface or flange-like configuration


58


on the frame


32


of the gate assembly


30


. The first radial surface


230


of member


224


is preferably provided with at least one elongated rib


232


projecting away from the radial surface


230


for enhancing the sealing ability of the sealing surface


230


. In a most preferred form, the first radial surface


230


of member


224


defines a second elongated rib


234


extending generally parallel to the first rib


232


and projecting away from the radial surface


230


to complement and further enhance the sealing ability of the radial surface


230


.




In the illustrated embodiment, a second radial surface


240


is disposed to an opposite side of the mounting portion


226


of member


224


in diametrically opposed relation to the first radial surface


230


. In this illustrated embodiment of member


224


, the mounting portion


226


is centrally disposed between the first and second radial surfaces


230


and


240


, respectively. As such, member


224


is reversible about the axis


226


thereby prolonging the useful life of the seal


222


. The second radial surface


240


of member


224


is preferably provided with at least one elongated rib


242


projecting away from the radial surface


240


for enhancing the sealing ability of the sealing surface


240


. The second radial surface


240


of member


224


defines a second elongated rib


244


extending generally parallel to the first rib


242


and projecting away from the radial surface


240


to complement and further enhance the sealing ability of the radial surface


240


.




As illustrated in

FIG. 21

, another portion of seal structure


220


involves providing a seal


252


transversely across the upper surface


55


of and toward an end of the door opposite from seal portion


222


. Suffice it to say, seal


252


is substantially identical to seal


222


discussed above. The seal


252


is preferably mounted to an exterior of and extends generally parallel to end wall


42


of frame


32


. Moreover, seal


252


extends across the upper surface


55


of door


50


and between the tracks


106


,


108


of the rack and pinion assembly


100


. The primary purpose of seal


252


is to inhibit contamination and insect infiltration between frame


32


of gate assembly


30


and the upper surface


55


of door


50


during transport and storage of the hopper car


10


.




As will be appreciated by those skilled in the art, and as illustrated in

FIG. 21

, the end wall


42


of frame


32


is required to have an opening or elongated slot


260


allowing for horizontal movement of the door


50


and the second modular element


60


,


80


arranged in association with the door


50


on the gate assembly


30


between open and closed positions. Of course, such an opening


260


likewise provides a conduit or passage extending across the entire bottom or lower surface


56


of door


50


. Opening


260


would normally permit dirt, dust, smoke, water and related debris to enter and, thus, contaminate the discharge plenum


57


and the lower surface


56


of the door


50


. Still another aspect of the present invention relates to providing a portion of seal structure


220


such as seal


262


transversely across the opening


260


between the lower surface


56


of the door


50


and the second modular element


60


,


80


arranged in association with the door


50


in a manner sealing the opening


260


to prevent contamination of the lower surface


56


of the door


50


and the discharge plenum


57


.




Suffice it to say, seal


262


is substantially identical to seal


222


discussed above. The seal


262


is preferably mounted to an exterior of and extends generally parallel to end wall


42


of frame


32


. Moreover, seal


262


extends across the lower surface


56


of door


50


and between the tracks


106


,


108


of the rack and pinion assembly


100


. Furthermore, the seal


262


extends across the second modular element


60


,


80


arranged in operable association with the door


50


on the gate assembly


30


. As such, the seal


262


functions as a compression/wiper seal. Notably, the dual radial surfaces on seal


262


advantageously extend in tangential relationship with the door


50


and the second modular element


60


,


80


arranged in association with the door


50


such that the single seal


262


serves a dual purpose while permitting horizontal movement of the elements


50


, and


60


,


80


in either linear direction without detracting or departing from its effectiveness as a seal. Furthermore, and as will be appreciated by those skilled in the art, seal


262


is configured to permit its energization in either linear direction of movement or travel of the elements


50


,


60


,


80


with which it is in sealing contact.




In the event it is desired to discharge commodity from the enclosure


12


of the hopper car


10


by means of pneumatics, the gate assembly


30


of the present invention is configured or conditioned with a door


50


and the open top pan assembly


60


as the modular element arranged in combination with the door


50


. Advantageously, the drive mechanism


88


of the gate assembly


30


allows for a predetermined range of free rotation of the operating shaft assembly


90


before the lost motion connection between the drive mechanism


88


and the door


50


collapses. The range of free rotation of the operating shaft assembly


90


ranges between about 90° and about 360°. In a most preferred form, the range of free rotation of the operating shaft assembly


90


is about 125°.




As will be appreciated, after the lost motion connection between the drive mechanism


88


and the door


50


collapses, the operating shaft assembly


90


will have had a range of free rotation thus allowing a relatively high impactual force or load to be imparted to the door


50


. The relatively high impactual force on the door


50


assists in moving the door


50


toward an open position. Once the door


50


is moved to an open position, the commodity in the enclosure


12


of car


10


freely passes into the open top pan assembly


60


for subsequent pneumatic discharge.




In the event that it is desired to discharge the commodity from the enclosure


12


of the car


10


by means of gravity only, the gate assembly


30


of the present invention would be conditioned such that door


50


is mounted on the frame


32


in combination with the sanitary plate


80


as the modular element. Advantageously, pan assembly


60


is secured to the frame


32


in the same manner to allow for its linear movement relative to the frame


32


thus yielding a unique modular design which readily lends itself to use of either component or element


60


,


80


in combination with the gate assembly


30


. Notably, both modular elements


60


,


80


act as a sanitary shield for the customer attachment flange


58


, the plenum chamber


57


, as well as the underside


56


of the door


50


.




When the sanitary plate


80


is arranged in combination with the gate assembly


30


as the other modular element, the drive mechanism


88


assures the plate


80


is removed from the beneath the door


50


before the door


50


is moved to an open position thereby eliminating the risk of placing substantial weight on a modular component not designed to support such weight. Additionally, moving the lower modular element


60


,


80


facilitates attachment of the customer unloading apparatus to the gate assembly


30


. That is, regardless of the setting or conditioning of the apparatus


116


, the sanitary plate


80


will be moved in timed relation relative to the door


50


and in such a manner thereby avoiding weighty placement of any commodity thereon. Alternatively, the sanitary plate


80


is configured to inhibit debris such as dirt, water, smoke and related matter from contaminating the discharge plenum


57


or the underside


56


of the door


50


.




The seal structure


220


of the present invention furthermore facilitates sealing of the frame


32


, door


50


, and the modular element


60


,


80


.arranged on the frame


32


relative to each other thereby inhibiting contaminants from moving therepast. The radial surfaces


230


,


240


on the seal structure


220


are preferably arranged in tangential relationship relative to the surfaces they are to seal thereby promoting linear movement of the elements


50


,


60


,


80


in either direction without detracting or departing from the ability of the seal structure


220


to maintain a sealing relationship therewith. The dual radial surface design furthermore promotes reversal of the seal structure


220


or use of the seal as a compression/wiper seal having energization abilities in either linear direction of movement of the elements with which it maintains a sealing relationship. Moreover, the seal structure


220


yields a continuous sealing function regardless of the linear position of the doorm


50


thus promoting the ability to throttle the flow rate of the commodity through the gate assembly.




From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and novel scope of the present invention. Moreover, it will be appreciated that the present disclosure is intended as an exemplification of the invention, and is not intended to limit the invention to the specific embodiments illustrated. Rather, the disclosure is intended to cover by the appended claims all such modifications and variations as fall within the scope of the claims.



Claims
  • 1. A discharge gate assembly for a railroad hopper car, comprising:a rigid frame defining an opening; a vacuum pan assembly carried for sliding linear movement on said frame along a predetermined path of travel between a first position, wherein said vacuum pan assembly underlies the opening defined by said frame, and a second position, wherein the pan assembly is slidably removed from beneath the opening defined by said frame, said vacuum pan assembly having a pneumatic discharge conduit extending outwardly therefrom in a direction extending transverse to the direction of movement of the pan assembly; a door operably interposed between the opening in said frame and said vacuum pan assembly, said door being slidably mounted on said frame for linear movement along a predetermined path of travel between open and closed positions; a mechanism for selectively engaging and moving either said door alone or said vacuum pan assembly from beneath the opening in said frame so as to selectively adapt the gate assembly for either gravity discharge or pneumatic discharge of material therethrough, wherein said mechanism includes an operating shaft supported on the frame for rotation about a fixed axis, and wherein a lost motion drive is provided between said operating shaft and said door such that said pan assembly moves a greater distance between said open and closed positions than does said door when said door moves between said open and closed positions.
  • 2. The discharge gate assembly according to claim 1 wherein said mechanism further includes a rack and pinion assembly arranged in combination with said operating shaft.
  • 3. The discharge gate assembly according to claim 2 wherein said rack and pinion assembly includes a pair of pinions mounted on said operating shaft assembly in laterally spaced relation relative to each other and a pair of laterally spaced racks in intermeshing relation with said pinions, said racks being slidably mounted on said frame for reciprocal movement relative to said door and pan assembly.
  • 4. The discharge gate assembly according to claim 3 wherein said mechanism further includes a manually operated apparatus arranged in combination with said rack and pinion assembly for selectively coupling either said pan assembly or said door to said operating shaft assembly.
  • 5. The discharge gate assembly according to claim 4 wherein said apparatus comprises a control rod mounted for endwise movement and including an actuator for operably engaging said pan assembly or said door depending upon the endwise disposition of said control rod relative to said frame.
  • 6. The discharge gate assembly according to claim 5 wherein said apparatus further includes a detent mechanism for releasably holding said control rod in a selected endwise position relative to said frame.
  • 7. The discharge gate assembly according to claim 1 further including seal structure disposed between said frame, said pan assembly and said door inhibiting debris from passing therebetween.
  • 8. A discharge gate assembly for a railroad hopper car, comprising:a rigid frame defining an opening; a vacuum pan assembly carried for sliding linear movement on said frame along a predetermined path of travel between a first position, wherein said vacuum pan assembly underlies the opening defined by said frame, and a second position, wherein the pan assembly is slidably removed from beneath the opening defined by said frame, said vacuum pan assembly having a pneumatic discharge conduit extending outwardly therefrom in a direction extending transverse to the direction of movement of the pan assembly; a door operably interposed between the opening in said frame and said vacuum pan assembly, said door being slidably mounted on said frame for linear movement along a predetermined path of travel between open and closed positions; a mechanism for selectively engaging and moving either said door alone or said vacuum pan assembly from beneath the opening in said frame so as to selectively adapt the gate assembly for either gravity discharge or pneumatic discharge of material therethrough, said mechanism including an operating shaft supported on the frame for rotation about a fixed axis and a rack and pinion assembly arranged in combination with said operating shaft, with said rack and pinion assembly including a pair of pinions mounted on said operating shaft in laterally spaced relation relative to each other and a pair of laterally spaced racks in intermeshing relation with said pinions, said racks being slidably mounted on said frame for reciprocal movement relative to said door and pan assembly, and wherein said mechanism further includes a manually operated apparatus arranged in combination with said rack and pinion assembly for selectively coupling either said pan assembly or said door to said operating shaft, said manually operated apparatus including a control rod mounted for endwise movement and including an actuator for operably engaging said pan assembly or said door depending upon the endwise disposition of said control rod relative to said frame and a detent mechanism for releasably holding said control rod in a selected endwise position relative to said frame, with said manually operated apparatus further including a spring for resiliently urging said control rod in a predetermined direction relative to said frame, and wherein a lost motion drive is provided between said operating shaft and said door such that said pan assembly moves a greater distance between said open and closed positions than does said door when said door moves between open and closed positions.
  • 9. A discharge gate assembly for a railroad hopper car, comprising:a rigid frame defining an opening; a vacuum pan assembly carried for sliding linear movement on said frame along a predetermined path of travel between a first position, wherein said vacuum pan assembly underlies the opening defined by said frame, and a second position, wherein the pan assembly is slidably removed from beneath the opening defined by said frame, said vacuum pan assembly having a pneumatic discharge conduit extending outwardly therefrom in a direction extending transverse to the direction of movement of the pan assembly; a door operably interposed between the opening in said frame and said vacuum pan assembly, said door being slidably mounted on said frame for linear movement along a predetermined path of travel between open and closed positions; a mechanism for selectively engaging and moving either said door alone or said vacuum pan assembly from beneath the opening in said frame so as to selectively adapt the gate assembly for either gravity discharge or pneumatic discharge of material therethrough, wherein said mechanism includes an operating shaft supported on the frame for rotation about a fixed axis; and a seal arranged in combination with the operating shaft of said mechanism said for providing a visual indication whether said mechanism has been operated to move said pan assembly or said door toward an open position.
Parent Case Info

This application is a Divisional of Ser. No. 09/156,430 filed Sep. 18, 1998.

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4376542 Hennessy Mar 1983 A
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4568224 Dugge et al. Feb 1986 A
4617868 Wahlstrom et al. Oct 1986 A
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