Patent Application
20210331721
This invention disclosure generally relates to railroad freight cars and, more specifically, to a railroad freight car coupling system including two individually operable and axially spaced assemblies for absorbing both buff and draft forces normally encountered by railroad freight cars during their in-service operation.
When a train consist is assembled in a rail yard, railcars run into and collide with each other to couple them to each other. Since “time is money”, the speed at which the railcars are coupled has significantly increased. Moreover, and because of their increased capacity, railroad freight cars are heavier than before. These two factors and others have resulted in increased damages to the railcars when they collide with each other and, frequently, the lading carried with such railcars.
As railroad car designers/builders continue in their efforts at reducing the weight of railcar designs, they have also identified a need and desire to protect the integrity of the railcar due to the excessive longitudinal loads/forces being placed thereon, especially as the railcars are coupled to each other. Whereas, such longitudinal loads/forces on the cars frequently exceed the design load limits set by the Association of American Railroads (“AAR”).
Providing an energy absorption system at opposed ends of each railcar has been long known in the art. In some applications, the energy absorption system at opposed ends of the car is captured within a defined space provided between front and rear pairs of stops arranged in operable combination with a centersill at each end of the railcar. Also, and once installed into operable combination with a railcar, the energy absorption system at opposed ends of the railcar is expected to yield energy absorption capabilities for the railcar over an extended period of time which, depending upon the level of service wherein the railcar is employed, can last for many years if not decades. Such energy absorption systems can typically be classified into multiple groups. In one form, an energy absorption system can include a type of hydraulic dampener for reducing the energy directed against the railcar. Another form of energy absorption system uses steel springs for reducing the energy directed against the railcar. Yet another form of energy absorption system utilizes a series of axially stacked elastomeric pads for absorbing and dampening the energy directed against the railcar. Still another type or form of energy absorption system utilizes a friction clutch assembly arranged at one end of a draft gear in operable combination with axially stacked elastomeric pads for absorbing and dampening the energy directed against the railcar.
The impacts occurring during the “make-up” of a train consist and during in-service train action subject the energy absorption system at opposed ends of the railcar to repeated buff impacts. In-service action also subjects the energy absorption system at opposed ends of the railcar to both repeated buff and draft events. The impacts associated with these events are transmitted from the railcar couplers to the respective energy absorbing system or cushioning assembly and, ultimately, to the railcar body. That is, as the railcar couplers are pushed and pulled in opposite longitudinal directions be it during in-service action and/or during the “make-up” of the train consist, such movements although muted by some degree by the cushioning assembly, are translated to the railcar body.
While use of a cushioning assembly in the form of a hydraulic dampener at opposed ends of the railcar offers certain advantages, such a cushioning assembly, however, is not without problems. Keeping in mind the service life of a railcar cushioning assembly can extend over several decades, repeated longitudinal translations and reciprocations of an extended rod or member forming an essential part of the hydraulic dampener quickly can adversely wear on and, ultimately, destroy sealing structure inherent with such a hydraulic dampener resulting in fluid loss whereby minimizing its ability to provide railcar protection. Moreover, known hydraulic devices may cause unintended brake hose uncoupling events that can cause train stoppages.
As mentioned, cushioning assemblies utilizing an axial stack of elastomeric pads to cushion the energy directed against the railcar are also known. Advantageously, and besides the benefits of cushioning the energy directed against the railcar, a cushioning assembly utilizing an axial stack of elastomeric pads furthermore yields the benefit of having at least a portion of the energy directed against the railcar being absorbed by the elastomeric pads. Unfortunately, and largely because of the both buff and draft directional forces being repeatedly applied to the cushioning assembly, such cushioning assemblies, especially when used in combination with today's railcars whereupon higher energy is being directed against them, have a lesser degree of effectiveness to impact forces.
Because of the relatively high energy environment wherein such cushioning units are being used, a cushioning assembly which utilizes a friction clutch assembly arranged at one end of the cushioning assembly and in operable combination with axially stacked elastomeric pads has proven very beneficial. These cushioning assemblies having a friction clutch arranged in operable combination therewith have been known to advantageously absorb high levels of energy imparted thereto. In some applications, such cushioning assemblies have advantageously been used in a tandem arrangement relative to each other to increase the level of energy which can be cushioned by such an arrangement.
These Applicants recognized and realized how particularly beneficial it could be if a purely mechanical energy absorption system could be used to replace the heretofore known cushioning devices utilizing hydraulics. That is, a purely mechanical energy absorption system could beneficially be used to cushion the impact forces directed at opposite ends of a railcar typically using a version of a hydraulic system while advantageously eliminating the leakage problems known with such hydraulic systems.
Unfortunately, the longitudinal distance separating the front and rear pairs of stops on the centersill normally associated with a hydraulic cushioning assembly complicates simply switching a purely mechanical cushioning assembly for a hydraulic cushioning assembly. Applicants have found the elongated space between the front and rear pairs of stops associated with a railcar which utilizes a cushioning assembly with a hydraulic unit demands use of two draft gear assemblies to fill the longitudinal space between the stops. Of course, and besides the increased costs associated with having such a duplicative design utilizing two draft gear assemblies, such proposal furthermore requires a follower to be disposed between the two back-to-hack draft gear assemblies. For these and other reasons, simply replacing a cushioning assembly which utilizes hydraulics with a mechanical system is far more complicated that it may initially appear.
It is also known to arrange a yoke in combination with the cushioning assembly. Typically, the yoke includes a back wall interconnected to top and bottom walls extending generally parallel to each other and toward an open end of the yoke. The cushioning assembly is typically sandwiched between the top and bottom walls of the yoke with a follower disposed toward a forward end of the cushioning assembly. The forward open end of the yoke is operably coupled to a railcar coupler which axially extends away from the cushioning assembly at each end of the railcar so as to allow adjacent railcars to be coupled to each other. Toward the open end thereof, the yoke is articulately connected to the railcar coupler through a suitable pin or key.
In buff events, a rear or butt end of a shank portion on the coupler moves axially inward and presses against a follower thus pushing the follower and cushioning assembly toward the pair of rear stops on the centersill. As the coupler and follower move under the influence of a buff event, a portion of the load or impact event is absorbed and dissipated by the cushioning assembly.
In draft events, unavoidable slack between adjacent but coupled railcars is taken up beginning at a starting or locomotive end of the train consist and ending at the other end of the train consist. As a result of the slack being progressively taken up, the speed difference between the railcars increases as the slack inherent with each railcar coupling at each end of the railcar in the train consist is taken up, with the resultant increase in draft events on the cushioning system. For example, when a locomotive on a train consist of railcars initially begins to move from a stopped or at rest position, there may be 100 inches of slack between the 50 or so pairs of couplings. This slack is taken up progressively by each pair of joined railcar couplings in the train consist. After the slack of the railcar coupling joining the last railcar to the remainder of the train consist is taken up, the next to the last railcar may be moving a few miles per hour. Given the above, it will be appreciated, the slack in the railcar couplers near the locomotive is taken up very rapidly while those railcars further from the locomotive are subject to very high energy events being placed thereon. Such large energy events are capable of damaging both the railcar structures and sometimes the lading in the railcar.
Thus, there is a need and continuing desire for a mechanical railroad freight car coupling system for absorbing both buff and draft forces normally encountered by railroad freight cars during their in-service operation and which has sufficient capacity and capabilities to replace heretofore known hydraulic dampeners at opposed ends of the railcar.
In view of the above, these inventors are the first to design and develop a purely mechanical railroad freight car coupling system which is simplistic in design while advantageously utilizing an elongated draft gear design including two individually operable and axially spaced assemblies arranged at opposite ends of the car for absorbing both buff and draft forces. The preferable elongated and single housing design of this invention disclosure significantly reduces material costs associated with this railroad freight car coupling system. Fewer parts and less material readily translates into reduced costs while maintaining higher performance over an extended travel in both draft and buff directions.
In accordance with one aspect of this invention disclosure, there is provided a draft gear assembly for absorbing, storing and returning energy directed against a railroad freight car, with said draft gear assembly being arranged in operable combination therewith. The railcar with which this invention finds utility has a centersill defining a pocket with a distance of about 38 inches to about 50 inches between front and rear stops. According to this aspect, the draft gear assembly has an axially elongated and hollow metal housing with a first open end and a second open end disposed in longitudinally spaced relation relative to each other. The housing is configured to fit within the pocket defined by the centersill on the railcar. In one embodiment, each end of the housing defines a series of longitudinally tapered and extended inner surfaces opening to and extending from each open end of the housing. In a preferred embodiment, the elongated housing has a unitary one-piece design.
In one embodiment, a first assembly and a second assembly are arranged in operable combination with the respective open end of the housing. In this embodiment, each assembly of the draft gear assembly is configured as a friction clutch assembly and includes a series of friction members equally spaced about a longitudinal axis of and extending toward a longitudinal center of the housing. Each friction member has axially spaced first and second ends and an outer surface extending between the ends. The outer surface on each friction member is operably engaged and associated with one of the longitudinally tapered and extended inner surfaces on the housing so as to define a first angled friction sliding surface therebetween for each clutch assembly. Each friction clutch assembly also includes a wedge operably held within an open end of the housing. The wedge of each friction clutch assembly is arranged for reciprocal movements relative to and has a free end extending beyond the respective open end of the housing so as to allow both buff and draft forces to be applied thereto during in-service operation of the railcar.
The wedge of each friction clutch assembly further defines a series of outer tapered surfaces equally spaced about the longitudinal axis of the housing. Each tapered outer surface on each wedge is operably engaged and associated with an inner surface on each friction member so as to define a second angled friction sliding surface therebetween and such that the axial movements of the wedge of each assembly moving inward relative to the respective open end of the housing causes the respective friction members to move longitudinally and radially inward relative to the respective open end of the housing. In one embodiment, the first and second friction clutch assemblies further includes a follower arranged within the housing. One surface of the follower is arranged in operable engagement with the second end of each friction member of the respective clutch assembly.
An axially elongated spring assembly is disposed in the elongated housing between the first and second friction clutch assemblies, disposed at opposed ends of the housing, for storing, dissipating and returning energy imparted to the draft gear assembly. The spring assembly includes an axial stack of multiple individual springs. Preferably, the spring assembly includes an axial stack often or more springs. Each spring preferably includes an elastomeric pad. Moreover, the pads of the spring assembly are preferably guided within the draft gear housing to inhibit buckling of the spring assembly. In operation of the draft gear assembly, the spring assembly functions in operable combination with the disposition of the first and second angled sliding surfaces of each friction clutch assembly to consistently and repeatedly absorb energy imparted to the draft gear over a combined range of travel of the wedge of each friction clutch assembly in an inward axial direction relative to the housing over the full range of travel of each friction clutch assembly at opposite ends of the draft gear assembly from full extension to full compression.
Preferably, the first and second angled friction sliding surfaces of the first and second friction clutch assemblies are substantially identical relative to each other. In another embodiment, the first angled friction sliding surface on the first friction clutch assembly is different from the first angled friction sliding surface on the second friction clutch assembly. In still another embodiment, the second angled friction sliding surface on the first friction clutch assembly is different from the second angled friction sliding surface on the second friction clutch assembly.
In one form, each elastomeric pad used in combination with the multitude of springs comprising each spring assembly has a toroidal outer configuration. Preferably, each elastomeric pad of the multitude of springs comprising each spring assembly has a Shore D hardness ranging between about 40 and about 60. In one embodiment, each elastomeric pad of the multitude of springs comprising each spring assembly has a similar hardness. In another embodiment, a plurality of elastomeric pads of the multitude of springs comprising the elongated spring assembly disposed closest to the first clutch assembly have a different elastomeric hardness as compared to those elastomeric pads of the multitude of springs comprising the elongated spring assembly which are disposed toward a middle of the elongated spring assembly. In still another embodiment, each elastomeric pad can have a composite construction including two different elastomeric materials each having a different Shore D hardness.
In accordance with another aspect of this invention disclosure, a draft gear assembly is adapted to be accommodated in a pocket defined by a railroad freight car centersill. The centersill has front and rear stops with a distance of about 38 inches to about 50 inches longitudinally separating the stops. In accordance with this aspect of the invention disclosure the draft gear assembly includes an axially elongated and hollow metal housing configured to fit between the stops and defining first and second longitudinally spaced open ends. Each end of the housing defining a series of longitudinally tapered and extended inner surfaces opening to and extending from each open end of the housing. In a preferred embodiment, the elongated housing is of unitary construction.
A first friction clutch assembly is arranged in operable combination with the first open end of the housing and a second friction clutch assembly is arranged in operable combination with the second open end of the housing. Each friction clutch assembly includes a series of friction members equally spaced about a longitudinal axis of and extending toward a longitudinal center of the housing. Each friction member has axially spaced first and second ends and an outer surface extending between the ends. The outer surface on each friction member is operably engaged and associated with one of the longitudinally tapered and extended inner surfaces on the housing so as to define a first angled friction sliding surface therebetween for each clutch assembly. Each friction clutch assembly also includes a wedge arranged for axial movements relative to and having a free end extending beyond the respective open end of the housing and to which an external force is applied during operation of the railroad freight car.
The wedge of each friction clutch assembly defines a series of outer tapered surfaces equally spaced about the longitudinal axis of the wedge. Each tapered outer surface on each wedge is operably engaged and associated with an inner surface on each friction member so as to define a second angled friction sliding surface therebetween for each clutch assembly and such that the wedge of each friction clutch assembly causes the respective friction members to move longitudinally and radially inward relative to the respective open end of the housing upon movement of the wedge inwardly of the housing. Each friction clutch assembly further including a follower arranged within the housing. One surface of the follower is arranged in operable engagement with the second end of each friction member of the respective clutch assembly.
According to this aspect of the invention disclosure, an elongated spring assembly is disposed in the housing between the first and second friction clutch assemblies for storing, dissipating and returning energy imparted to the draft gear assembly. The spring assembly includes an axial stack of springs. In one form, the spring assembly includes at least ten or more individual springs which are axially guided with the housing. The spring assembly is configured to function in operable combination with the disposition of the first and second angled sliding surfaces of each friction clutch assembly such that the draft gear assembly consistently and repeatedly absorbs energy imparted to the draft gear assembly over a combined range of travel of the wedge member of each friction clutch assembly in an inward axial direction relative to the housing ranging between about 6.25 inches and about 9.5 inches. In one form, a separator plate forms part of the spring assembly and is disposed proximately mid-length of the spring assembly between two adjacent individual springs of the spring assembly.
In one form, the first and second angled friction sliding surfaces of the first and second clutch assemblies are substantially identical relative to each other. In another form, the first angled friction sliding surface on the first clutch assembly is different from the first angled friction sliding surface on the second clutch assembly. In another embodiment, the second angled friction sliding surface on the first clutch assembly is different from the second angled friction sliding surface on the second clutch assembly.
Preferably, each elastomeric pad of the multitude of springs comprising each spring assembly has a toroidal outer configuration. In one form, each elastomeric pad of the multitude of springs comprising each spring assembly has a Shore D hardness ranging between about 40 and about 60. In a preferred embodiment, each elastomeric pad of the multitude of springs comprising each spring assembly has a similar hardness. In yet another embodiment, a plurality of elastomeric pads of the multitude of springs comprising the elongated spring assembly disposed closest to the follower of the respective clutch assembly have a different elastomeric hardness as compared to those elastomeric pads of the multitude of springs comprising the elongated spring assembly which are disposed toward a middle of the spring assembly.
According to another aspect of this invention disclosure, there is provided an energy absorption system for a railroad freight car having a centersill defining a pocket having front and rear stops, with a longitudinal distance of about 38 inches to about 50 inches longitudinally separating the stops. A coupler has a head portion longitudinally extending beyond a free end of the centersill and a shank portion connected to and extending from the head portion.
According to this aspect of the invention disclosure, the energy absorption system further includes a draft gear assembly including an axially elongated and hollow metal housing defining first and second longitudinally spaced open ends. At least the first open end of the housing defines a series of longitudinally tapered and extended inner surfaces opening to and extending from the open end of the housing toward a longitudinal center of the housing. A friction clutch assembly is arranged in operable combination with the first open end of the housing. The friction clutch assembly includes a series of friction members equally spaced about a longitudinal axis of and extending toward the longitudinal center of the housing. Each friction member has axially spaced first and second ends and an outer surface extending between the ends. The outer surface on each friction member is operably engaged and associated with one of the longitudinally tapered and extended inner surfaces on the housing so as to define a first angled friction sliding surface therebetween for the clutch assembly.
In this embodiment, the friction clutch assembly also includes a wedge arranged for axial movements relative to and having a free end extending beyond the first open end of the housing and to which an external force is applied during operation of the railroad freight car. The wedge of the friction clutch assembly defines a series of outer tapered surfaces equally spaced about the longitudinal axis thereof. Each tapered outer surface on the wedge is operably engaged and associated with an inner surface on each friction member so as to define a second angled friction sliding surface therebetween for the clutch assembly and such that the wedge of the friction clutch assembly causes the respective friction members to move longitudinally and radially inward relative to the open end of the housing upon inward movement of the wedge. The friction clutch assembly further includes a follower arranged within the housing. One surface on the follower is arranged in operable engagement with the second end of each friction member of the clutch assembly.
A spring assembly is disposed within and between the first and second ends of housing for storing, dissipating and returning energy imparted to the draft gear assembly. The spring assembly includes an axial stack of individual springs. In a preferred form, at least ten individual springs are used in combination relative to each other. The spring assembly is preferably configured to promote axial guidance of the spring assembly within the housing.
At the opposite or second open end of the housing, a member is arranged for limited reciprocating axial movements within and relative to the second open end of the housing. The member at the second end of the housing is biased outwardly of the housing by the spring assembly. Such member at the second end of the housing has a free end extending beyond the second open end of the housing and to which an external force is applied during operation of the railroad freight car.
The spring assembly is configured to function in operable combination with the disposition of the first and second angled sliding surfaces of the first friction clutch assembly and the member disposed at the second end of the housing such that the draft gear assembly consistently and repeatedly absorbs energy imparted to the draft gear assembly over a combined range of travel ranging between about 6.25 inches and about 9.5 inches.
According to this aspect of the invention disclosure, the energy absorption system further includes a yoke having a back wall with top and bottom walls extending therefrom. The shank portion of the coupler is operably connected toward a forward and open end of the yoke while the back wall of the yoke is adapted to operably engage the draft gear assembly when the railroad freight car is operated in draft.
Preferably, the housing of the draft gear assembly has a generally cylindrical cross-sectional configuration extending for a majority of the distance between the first and second open ends thereof. In a preferred embodiment, the elongated housing of the draft gear assembly is of unitary construction.
While this invention disclosure is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described preferred embodiments, with the understanding the present invention disclosure is to be considered as setting forth exemplifications of the disclosure which are not intended to limit the invention disclosure to the specific embodiments illustrated and described.
Referring now to the drawings, wherein like reference numerals indicate like parts throughout the several views, there is shown in
As shown in
The draft sill or centersill 14 shown by way of example in
In a preferred embodiment, the front and rear pairs of stops 23 and 25, respectively, extend the full height of the draft sill or centersill 14. In the illustrated embodiment, and as is required when a hydraulically operated cushioning assembly is used to absorb energy incurred during in-service operations, a pair of vertically disposed middle or center stops 27 are arranged in operable combination with the centersill 14. Typically, the middle stops 27 are arranged on and in combination with the centersill 14 proximately midlength between the front and rear pairs of stops 23 and 25, respectively.
In the embodiment illustrated by way of example in
In the embodiment illustrated in
The energy absorption system 50 of the present invention disclosure includes a purely mechanical design having demonstrated the capability of heretofore known hydraulic dampeners with lesser concerns over maintenance. To facilitate use and assembly thereof to other components of the railcar 10, the essence of system 50 involves one draft gear assembly 52 including first and second independent operable assemblies disposed at opposed ends of the energy absorption system 50. In the embodiment illustrated by way of example in
Each open end of housing 60 is provided with a plurality (with only one being shown in
Returning to the embodiment illustrated in
Preferably, the first friction clutch assembly 80 and second friction clutch assembly 80′ of draft gear assembly 52 are substantially identical in construction and operation relative to each other. Accordingly, only friction clutch mechanism 80 will be discussed in detail. Returning to
As shown by way of example in
In a preferred embodiment, the friction members or shoes 82 of each clutch assembly are substantially identical to each other. In the embodiment illustrated in
In one form, the angle e of the first angled friction sliding surface 86 ranges between about 1.5 degrees and about 5 degrees relative to the longitudinal axis 62 of the draft gear assembly 52. In a preferred embodiment, the angle e of the first angled friction sliding surface 86 ranges between about 1.7 degrees and about 2 degrees relative to the longitudinal axis 62 of the draft gear assembly 52.
In the illustrated embodiment, each friction clutch assembly 80, 80′ further includes a wedge or actuator 90 arranged for axial movements relative to the respective open end 80, 80′ of housing 60. The wedge or actuator is formed from any suitable metallic material. As shown in
As illustrated in
In one embodiment of this invention disclosure illustrated in
Returning to the embodiment illustrated by way of example in
In the embodiment illustrated by way of example in
In the embodiment illustrated by way of example in
In a preferred embodiment, each friction clutch assembly 80, 80′ further includes a spring seat or follower 106 arranged within the hollow chamber 68 of housing 60 and disposed generally normal or generally perpendicular to the longitudinal axis 62 of the draft gear assembly 52. Spring seat 106 is adapted for reciprocatory longitudinal or axial movements within the chamber 68 of housing 60 and has a first surface 107 arranged in operable combination with the second or rear end of each friction member or shoe 82 of a respective clutch assembly. As shown in
Returning to
In the embodiment of draft gear assembly 52 illustrated in
Turning to
In one example, the elastomeric pad 114 is formed from a polyester material having a Shore D durometer hardness ranging between about 40 and about 60 and having an elastic strain to plastic ratio of about 1.5 to 1. The working process and methodology for creating each spring unit 112 involves creating preformed block which is precompressed for a percentage of the preformed height of the preform thereby transmuting the preform into an elastomeric spring. In this regard, attention is invited to U.S. Pat. No. 4,198,037 to D. G. Anderson; the entirety of which is incorporated herein by reference.
In an alternative embodiment of this invention disclosure, the durometer hardness of those elastomeric springs comprising spring assembly 110 may be different relative to each other. That is, the cumulative durometer hardness of the springs 112 disposed closet to the clutch assembly 80 can be different from the cumulative hardness of the springs 112 disposed closet to the clutch assembly 80′. Alternatively, the cumulative durometer hardness of the springs 112 disposed closet to the respective clutch assemblies 80, 80′ can be different from the cumulative hardness of the springs 112 disposed closer to longitudinal center of the spring assembly 110. In another form, one or more of the elastomeric pads 114 forming spring assembly 110 can be formed as a composite structure of the type disclosed in U.S. Pat. No. 5,868,384 to D. G. Anderson; the entirety of which is incorporated herein by reference. Suffice it to say, each pad 114 can be formed from at least two layered elastomers each having different Shore D harnesses and different operating characteristics from the other. Such designs readily allow the functionality and performance characteristics of the cushioning assembly or energy absorption system 50 of the present invention disclosure to be “fine-tuned” to the particular environment wherein the cushioning assembly or energy absorption system 50 of the present invention disclosure is to be used and function.
Returning to
As shown in
In the embodiment illustrated by way of example in
With the present invention disclosure, the draft gear assembly 52 of the energy management assembly 50 can be relatively easily installed in the pocket 32 of centersill 14 by using standard, well known installation procedures and into operable combination with the coupler 40. Returning to
Yoke 120 is preferably designed similar to that disclosed in further detail in coassigned U.S. Pat. No. 9,598,092; the full disclosure of which are incorporated herein by reference. In the embodiment illustrated in
Returning to
During draft travel, the co-planar inboard-facing stop surfaces 143, 145 and 153, 155 on the yoke 120 will eventually and operably contact and engage with either the front stops 23 or middle stops 27 (
In the full draft position shown by way of example in
In the illustrated embodiment, and when in a full buff position, the individual spring units 112 of spring assembly 110 (
An alternative embodiment of a cushioning assembly or energy absorption system embodying principals and teachings of this invention disclosure and which includes a purely mechanical design having demonstrated the capability of heretofore known hydraulic dampeners with lesser concerns over maintenance is illustrated by way of example in
As with system 50, the essence of system 250 involves a unitary draft gear assembly 252 including two individually operable and axially spaced assemblies for absorbing both buff and draft forces normally encountered by railroad freight cars during their in-service operation. In this embodiment. the draft gear assembly 252 includes an axially elongated metallic and hollow housing 260 defining a longitudinal axis 262. Housing 260 defines a first open end 264 and a second open end 266 disposed in longitudinally spaced axial relation relative to each other. The unitary energy absorption system 250 is specifically configured and designed to fit within the pocket 36 (
In the alternative draft gear assembly embodiment, the axially spaced assemblies operably associated with the draft gear assembly 252 are each preferably designed as friction clutch assemblies. As such, each open end 264, 266 of housing 260 is provided with a plurality (with only one being shown in
In this alternative embodiment of the draft gear assembly, the friction clutch assemblies are generally identified by reference numerals 280 and 280′. Suffice it to say, the friction clutch assemblies 280 and 280′ of draft gear assembly 252 are substantially identical in construction and operation relative to each other and to the clutch assemblies 80, 80′ discussed above. That is, each friction clutch mechanism 280, 280′ includes a plurality of friction members or shoes 282 equally arranged about axis 262 and in operable combination with the respective open end 264, 266 of housing 260.
In the embodiment illustrated by way of example in
In a preferred embodiment, each friction clutch assembly 280, 280′ further includes a spring seat or follower 306 arranged within the hollow chamber 268 of housing 260 and disposed generally normal or generally perpendicular to the longitudinal axis 262 of the draft gear assembly 252. Suffice it to say, spring seat 306 is substantially identical to and functions the same as the spring seat 106 described in detail above.
An axially elongated elastomeric spring assembly 310 is disposed and slidable within the housing 260 of the draft gear assembly 252 between the first and second friction clutch assembly 280, 280′ and forms a resilient column for storing, dissipating and returning energy imparted or applied to the opposite ends of the draft gear assembly 252 during operation of the coupling system 20. The spring assembly 310 is precompressed during assembly of the draft gear assembly 252 and serves to: 1) maintain the components including the friction members and wedge of each friction clutch assembly 280, 280′ in operable combination relative to each other both during operation of the draft gear assembly 252 as well as during periods of non-operation of the draft gear assembly 252; and, 2) maintain the free end of the wedge 290 of each friction clutch assembly 280, 280′ pressed against the respective follower; and, 3) maintain each follower pressed against the respective stops 25 on the centersill 14.
As with spring assembly 110, in this embodiment of draft gear assembly 252, the spring assembly 310 is configured with a plurality of individual units or springs 312 arranged in axially stacked adjacent relationship relative to each other. In one form, the spring assembly 310 includes a plurality of individual springs arranged in an axial stack relative to each other. In a preferred embodiment, at least ten individual springs are arranged in stacked relationship relative to each other. Preferably, the individual springs 312 of spring assembly 310 are substantially similar to those spring units or springs discussed above regarding spring units 112.
In the embodiment shown in
Preferably, spring stack 310A is comprised of five or more spring units 312 and axially extends between separator 320 and the friction clutch 280 at the open end 264 of the draft gear assembly 252. Preferably, spring stack 3108 is comprised of five or more spring units 312 and axially extends between separator plate 320 and the friction clutch 280 at the open end 266 of the draft gear assembly 352. The purpose of the separator plate 320 is to provide the spring assembly 310 with different spring rates or characteristics on opposite sides of the separator 320.
As shown in
Still another alternative embodiment of a cushioning assembly or energy absorption system embodying principals and teachings of this invention disclosure and which includes a purely mechanical design having demonstrated the capability of heretofore known hydraulic dampeners with lesser concerns over maintenance is illustrated by way of example in
As with system 50, the essence of system 450 involves a draft gear assembly 452 having dual energy absorption capability. In this alternative embodiment of a cushioning assembly or energy absorption system illustrated by way of example in
In the embodiment of a cushioning assembly or energy absorption system illustrated in
In the embodiment illustrated in
As shown, an outer end 483 of plunger 482 preferably has a generally flat face 484 which presses against a railroad car follower disposed for axial movements within the open end 464 of housing 460. Preferably, and when the cushioning assembly or energy absorption system 450 is in a neutral position or condition within the pocket 32 defined by the centersill 14 (
In the embodiment illustrated by way of example in
Once the first assembly 480 is assembled relative to the draft gear assembly, the lugs 489 on the plunger 482 are disposed relative to the lugs 487 on the housing 460 to allow the plunger 482 to axially reciprocate relative to the housing 460 while inhibiting inadvertent separation of the plunger 482 relative to the housing 460 during operation of the draft gear assembly 450. As will be readily appreciated by those skilled in the art, any of several other designs, including a guide rod having cooperating instrumentalities for limiting the axial stroke or reciprocatory movements of the plunger 482, could equally be used to allow plunger 482 to axially reciprocate relative to the housing 460 while inhibiting inadvertent separation of the plunger 482 relative to the housing 460 during operation of the draft gear assembly 450 without detracting or departing from the spirit and scope of this invention disclosure.
In the embodiment illustrated in
A spring assembly 510 is disposed and slidable within the housing 460 of the draft gear assembly 452 between the first assembly 480 and second assembly 480′. The spring assembly 510 forms a resilient column for storing, dissipating and returning energy imparted or applied to the opposite ends of the draft gear assembly 452 during operation of the coupling system 420. The spring assembly 510 is precompressed during assembly of the draft gear assembly 452 and serves to: I) maintain the components of the first assembly 480 and second assembly 480′ in operable combination relative to each other during buff and draft operations of the draft gear assembly 452 as well as during periods of non-operation of the draft gear assembly 452; and, 2) maintain the free end of the plunger 482 of the first assembly 480 and the wedge 490 of the second assembly 480′ pressed against the respective followers; and, 3) maintain the followers pressed against the respective stops 23, 25 on the centersill 14.
As with spring assembly 110 discussed above, in this embodiment of draft gear assembly 452, the spring assembly 510 is preferably configured with a plurality of individual units or springs 512 arranged in axially stacked adjacent relationship relative to each other. In one form, the spring assembly 510 includes an axial stack of individual springs. Preferably, at least ten individual springs are arranged in stacked relationship relative to each other. Each individual spring 512 of spring assembly 510 is substantially similar to that discussed above regarding spring 112.
In summary, the cushioning assembly or energy absorption system of the present invention disclosure includes a purely mechanical design having demonstrated the capability of heretofore known hydraulic dampeners with lesser concerns over maintenance. The essence of energy absorption system involves a draft gear assembly embodying two individually operable and axially spaced assemblies for absorbing both buff and draft forces normally encountered by railroad freight cars during their in-service operation
From the foregoing, it will be observed that numerous modifications and variations can be made and effected without departing or detracting from the true spirit and novel concept of this invention disclosure. Moreover, it will be appreciated, the present disclosure is intended to set forth exemplifications which are not intended to limit the disclosure to the specific embodiments illustrated. Rather, this disclosure is intended to cover by the appended claims all such modifications and variations as fall within the spirit and scope of the claims.
This patent application relates to a co-pending and co-assigned U.S. PROVISIONAL patent application, namely, U.S. patent application Ser. No. 63/013,666 filed Apr. 22, 2020; the entirety of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63013666 | Apr 2020 | US |
