The present invention generally relates to railroad hopper cars and, more particularly, to a improved hatch cover for releasably closing a hatch opening in a roof of a railroad hopper car.
Railroad hopper cars have been used for years to transport particulate and granular material such as grain and the like. Covered railroad hopper cars have been constructed and arranged with a roof for protecting the railcar contents from contaminants and weather related elements. Access to an interior of the railcar from above is through a hatch opening in the roof of the railcar. One type of railcar in wide spread use presents a hatch opening typically extending the length of the railcar. In some railcar designs, the hatch opening can be configured with arcuate end portions. Cowled coaming, upstanding from the roof, typically extends circumferentially or peripherally about the hatch opening.
The hatch opening in the roof of the railcar is closed during transport by a series of individual hatch covers typically arranged in end-to-end relationship relative to each other. The hatch covers are usually pivotally connected to the roof along one side thereof and can be swung to an open position. In one form, each hatch cover can measure in length from eight to thirteen feet and weigh approximately 100 pounds. Suffice it to say, the hatch covers are sized to extend across and over a top rim of the coaming to cover the hatch opening. Typically, the hatch covers are secured in a closed position during transport by a series of batten bars and hold downs.
Known hatch covers used to close hatch openings in covered hopper cars suffer from numerous problems. One form of known hatch cover is formed of fiberglass or other suitable moldable material. Fiberglass hatch covers, however, are susceptible to deteriorating ultraviolet rays as well as weather related deterioration factors. Fiberglass hatch covers must be designed and manufactured with reinforced profiles for accommodating mounting of several hinge structures along the length thereof to allow pivotal movement of the hatch cover between open and closed positions. As will be appreciated, the need for reinforced profiles adds to the complexity of the hatch cover design. Moreover, the need for high temperatures and pressures in the hatch cover molding process leads to relatively high cost and other obvious problems. Additionally, the molding compound does not readily flow into deep ribs, bosses and related reinforcement areas of the hatch cover. Accordingly, reduced reinforcement and a decreased stiffening effect often results from imperfect formation of the hatch cover.
Although specifically directed not to walk across or stand on such railcar hatch covers, it is inevitable workers tend to stand or walk across the closed hatch covers as commodity is added or loaded into the railcar. Accordingly, hatch covers have typically been structurally designed with a “hat” section profile as an attempt to add strength and stiffness to the hatch cover. As will be appreciated, requiring such a profile adds to the complexity of the hatch cover design along with manufacturing process and, again, adds to the overall cost of the hatch cover. Moreover, the need for such a profile to accomplish rigidity and stiffness increases the weight of the hatch cover whereby detracting from the overall carrying capacity of the railcar.
Additionally, known railcar hatch covers typically include generally vertical sidewall structure arranged on opposite lateral sides of the longitudinal centerline of the hatch cover and which depend from a center section of the hatch cover. Each depending sidewall is joined to the center section of the hatch cover. Since each depending sidewall terminates below the top rim of the coaming, the sidewalls of the hatch cover advantageously inhibit dirt and related debris from passing between the hatch cover and the top rim of the coaming.
A problem has developed in known hatch cover designs. Cracks have been known to form in the material used to form the hatch cover. In some designs, such cracks have occurred and radiated in a corner region where the generally vertical depending sides of the hatch cover are joined to the center section of the hatch cover. It appears the cracks may be formed by the concentration of stress at the corner regions of the hatch cover. Such cracks allow water, and related contaminants to leak through the hatch cover thereby damaging the contents of the railroad hopper car. This is simply unacceptable.
Moreover, the Association of American Railroads (“AAR”) has developed and established standards which set forth specific and requirements for the design and development for railcar hatch covers. One such standard established by the AAR defines specific criteria for maintaining the hatch cover in a predetermined sealing relationship with the top rim of the coaming when the hatch cover closed. Hatch covers must be sufficiently rigid to qualify under this and related AAR standards. In those hatch cover designs wherein the length of the hatch cover can measure up to thirteen feet between opposite ends thereof, this standard presents difficult design challenges.
Thus, there is a continuing need and a desire for a railcar hatch cover which has a simplistic lightweight design, and offers enhanced strength and stiffness over comparable known railcar hatch covers.
In view of the above, there is provided a railcar hatch cover adapted to be positioned relative to a longitudinally elongated hatch opening defined in a roof of a covered railroad hopper car. The railcar roof further includes upstanding coaming arranged in surrounding relation relative to the hatch opening. Structure is provided for mounting the hatch cover for movement between open and closed positions.
According to one aspect, the hatch cover includes a high strength and highly rigid laminate panel having longitudinally spaced ends and a centerline. The laminate panel includes an inner aluminum member, an outer aluminum member, and a solid plastic core adhered to confronting surfaces of the inner and outer aluminum members. The inner and outer aluminum members each have a grain extending longitudinally of the panel. A cross-section of the laminate panel includes a center section with two generally parallel and generally vertical sides, with one generally vertical side of the panel being laterally disposed to each side of the longitudinal centerline of and extending the length of the panel. Each generally vertical side of the panel is joined to center section of the panel along a longitudinally elongated curved corner having a radius of less than 1.5 inches. Moreover, compressible gasket structure is secured to an underside of the center section of the laminate panel in the vicinity of each corner for engaging and pressing against a top rim of the coaming to seal the hatch cover whereby inhibiting contaminants from passing between the closed cover and the coaming on the railcar. Additionally, the laminate panel is provided with longitudinally spaced structure, arranged inwardly from the opposed ends of and secured across the laminate panel, for adding further strength and rigidity to the hatch cover.
Preferably, one generally vertical side of the laminate panel depends from the center section a greater distance than does the other generally vertical side of the laminate panel. In one form, the center section of the laminate panel has a vaulted formation to allow the hatch cover to shed water after being secured to the railcar. Preferably, each hatch cover further includes an end cover attached to and carried by each end of the laminate panel. In one form, the end cover includes an upstanding ridge extending laterally across the end of the hatch cover, with the upstanding ridge being configured to cooperate with a batten bar to hold the hatch cover in the closed position.
According to another aspect, the hatch cover includes a laminate panel of sufficient size to cover at least a longitudinal lengthwise portion of the hatch opening. The laminate panel has longitudinally spaced ends and includes an inner aluminum member, an outer aluminum member, and a solid plastic core adhered to confronting surfaces of the inner and outer members. A cross-section of the laminate panel including a flat center section extending substantially between the ends of the panel with two generally vertical sides disposed to opposite sides of a longitudinal centerline of and extending between the ends of the panel and depending from the center section. To inhibit leaking, the center section and the generally vertical sides of the laminate panel are a continuous structure. The sides are joined to the center section along a longitudinally elongated corner. Compressible gasket structure is secured to an underside of the generally flat center section of the laminate panel for engaging and pressing against an upper rim of the coaming to seal the hatch cover in a closed position. Longitudinally spaced structure disposed inwardly from the opposed ends of and secured across the outer panel of the laminate panel adds strength and rigidity to the hatch cover.
In one form, one generally vertical side of the laminate panel depends from the center section of the panel a greater distance than does the other generally vertical side of the laminate panel. Preferably, the center section of the laminate panel has a vaulted formation to allow the hatch cover to shed water when closed. In a preferred embodiment, the railcar hatch cover further includes an end cover attached to and carried by each end of the laminate panel. Each end cover preferably includes an upstanding ridge extending laterally across the end of the hatch cover, with the upstanding ridge being configured to cooperate with a batten bar to hold the hatch cover in the closed position. To inhibit contaminants from moving past the closed hatch cover, the batten bar has compressible gasket structure nested therein for cooperatively combining with the raised ridge on the end cover when the hatch cover is in the closed position.
According to yet another aspect, the railcar hatch cover includes a laminate panel having longitudinal spaced ends and including an extruded inner member, an extruded outer member, and a solid plastic core material adhered to confronting surfaces of the inner and outer members. The laminate panel has a center section extending substantially between the ends of the panel with two generally parallel and generally vertical sides. One generally vertical side of the panel is disposed to each side of a longitudinal centerline of and extends between the ends of the panel and depending from the center section. The laminate panel has a flexural rigidity or stiffness S derived as follows:
S=E×I
wherein “E” is the flexural modulus of the material and “I” is the Moment of Inertia of the hatch cover;
and wherein the laminate panel has an “E” value equal to 4×106 p.s.i.;
and wherein the cross-sectional configuration of the center section and two sides of the laminate panel define a Moment of Inertia for the panel such that the laminate panel has a Stiffness or flexural rigidity equal to 2.407×107 lbs.×inches2. Compressible gasket structure is secured to an underside of the center section of the laminate panel for engaging and pressing against a rim of the railcar coaming to seal the hatch cover in a closed position. Longitudinally spaced structure is disposed inwardly from the opposed ends of and is secured across the outer member of the laminate panel for adding strength and rigidity to the hatch cover.
According to this aspect, the inner and outer members are extruded from aluminum and have a grain extending longitudinally of the laminate panel. Preferably, one generally vertical side of the laminate panel depends from the center section of the panel a greater distance than does the other generally vertical side of the laminate panel.
In one form, the center section of the laminate panel has a vaulted formation to allow the hatch cover to shed water when in a closed position. The hatch cover furthermore preferably includes an end cover attached to and carried by each end of the laminate panel. Each end cover preferably includes an upstanding ridge extending laterally across the end of the hatch cover, with the upstanding ridge being configured to cooperate with a batten bar to hold the hatch cover in the closed position. To retard the passage of contaminants past the closed hatch cover, the batten bar has compressible gasket structure nested therein for cooperatively combining with the raised ridge on the end cover when the hatch cover is in the closed position.
According to yet another aspect, the railcar hatch cover includes a rigid frame assembly comprised of a series of spaced and generally parallel metal support members, a pair of end pieces, and pair of longitudinally elongated rigid metal members extending substantially an entire length of each hatch cover. The metal support members and the end pieces each have a center section, and two end sections arranged in depending relation relative to the center section. In this form, the end sections of each support member and end pieces are fastened toward a distal end thereof to one of the rigid metal members. A laminate panel of sufficient size to cover at least a longitudinal lengthwise portion of said hatch opening is secured to the frame assembly. The laminate panel has longitudinally spaced ends and includes an inner aluminum member, an outer aluminum member, and a solid plastic core adhered to confronting surfaces of said inner and outer members. A cross-section of the laminate panel includes a center section and two generally vertical sides disposed to opposite sides of a longitudinal centerline of and extending between the ends of the panel and depending from the center section.
In this embodiment, one side of the laminate panel depends from the center section a greater distance than the other side of the laminate panel. Preferably, the center section of the laminate panel has a vaulted formation to allow the hatch cover to shed water. In this form, the railroad car hatch cover has a flexural rigidity S derived as follows:
S=E×I
wherein “E” is the flexural modulus of the material and “I” is the Moment of Inertia of the hatch cover;
and wherein said laminate panel has an “E” value equal to 4×106 p.s.i.;
and wherein the cross-sectional configuration of the center section and two sides of said laminate panel define a Moment of Inertia for said panel such that said laminate panel has a flexural rigidity or Stiffness equal to 2.407×107 lbs.×inches2. According to this aspect, each side of the laminate panel preferably defines an angle ranging between 80° and about 115° relative to the center section and is joined to the center section of the panel along a longitudinally elongated curved corner section having a radius of less than 1.5 inches.
While this disclosure is susceptible of embodiment in multiple forms, there is shown in the drawings and will hereinafter be described a preferred embodiment of the disclosure, with the understanding the present disclosure sets forth an exemplification which is not intended to limit the invention disclosure to the specific embodiment illustrated and described.
Referring now to the drawings wherein like reference numeral indicate like parts through the several views, in
In the illustrated embodiment, railcar 10 has an elongated and longitudinally extending hatch opening 24 defined toward a central portion of the roof 20 for loading granular materials or commodity into the car 10. The hatch opening 24 is generally centralized with respect to the longitudinal centerline 22 of the car 10. In one form, the hatch opening 24 has a generally rectangular configuration between opposed ends thereof.
Turning to
Returning to
In the illustrated embodiment, the covers 32a through 32d are movable between open and closed positions relative to the hatch opening 24 on railcar 10. In one form, the hatch covers 32a through 32d are removably maintained in a closed position by a series of conventional batten bars 34 and hold downs 35. As known, each batten bar 34 is pivotally secured toward one end thereof to the roof 20 and extends across end regions of the hatch covers. An opposite end of each batten bar 34 is releasably secured to the roof 20 by a conventional latch structure 36. In the illustrated embodiment, the latch structure 36 for releasably securing the batten bar 34 to the roof 20 can be similar to that disclosed in U.S. Pat No. 4,635,979 to O. E. Blume; the applicable portions of which are incorporated herein by reference. As will be discussed below, each batten bar 34 is constructed such that, when secured in place, the batten bars 34 inhibit debris and related contaminants, including the elements of weather, from passing between the confronting and preferably abutting ends of the respective covers. In one form, each hold down 35 extends from the side of the hatch cover opposite that side allowing for pivotal movement of the hatch cover and can be arranged in operable combination with conventional latch structure 36 for releasably holding the hatch cover in a closed position.
As shown in
In the embodiment illustrated in
Turning to
The aluminum skins 62 and 64 add strength, stiffness and rigidity to each hatch cover 32a through 32d while their minimal thickness significantly reduces the weight of the each hatch cover. In one form, the skins 62 and 64 are each approximately 0.02 inches thick. The cumulative thickness of the skins 62, 64 and core 60 measures about 0.236 inches.
As shown in
Preferably, the laminate panel 40 for each hatch cover is formed using a stamping process. In a most preferred form, the laminate panel 40 of each hatch cover is formed as a result of a one-step stamping process.
The cross-sectional configuration of the panel 40 has been designed whereby allowing each hatch cover to pass the stringent AAR standards established for railcar hatch covers. More specifically, each hatch cover has a flexural rigidity or stiffness S derived as follows:
S=E×I
wherein “E” is the flexural modulus of the material and “I” is the Moment of Inertia of each hatch cover;
and wherein the laminate panel 40 has an “E” value equal to 4×106 p.s.i.;
and wherein the cross-sectional configuration of the center section 52 and two generally vertical side section 52 and 54 of the laminate panel define a Moment of Inertia for the panel 40 such that the laminate panel has a flexural rigidity of 2.407×107 lbs.×inches2.
As shown in
In the form illustrated by way of example in
Turning again to
Each hatch cover forming hatch cover assembly 30 (
With continued reference to
In the embodiment shown in
Preferably, each hatch cover 32a through 32d has two end pieces operably associated therewith. So as to reduce costs, the end pieces associated with opposed ends of each of the intermediate hatch covers 32b and 32c are substantially identical relative to each other. The end pieces associated with the intermediate hatch covers 32a through 32d will be generally referred to be reference numeral 100. Since the end pieces 100 associated with the intermediate hatch covers are substantially identical only the end piece 100 associated with hatch cover 32b will be discussed in detail.
As illustrated
In the embodiment illustrated by way of example in
Returning to
As shown in
Each end piece 140 includes a center section 142 and depending side sections 144 and 146. Unlike the end pieces 100 secured to the intermediate hatch covers 32b and 32c, however, the end piece 140 is preferably provided with a simple and generally flat plate-like configuration 148 which preferably follows the cross-sectional configuration or profile at the open or terminal end of the laminate panel 40 and effectively closes the open end of the end hatch cover in a manner inhibiting substantial quantities of contaminants, i.e., dust, dirt and related debris from moving therepast toward the gasket structure 80 and into the railcar 10.
In a preferred form, each hatch cover 32a through 32d furthermore includes a rigid frame structure comprised of the end pieces arranged at the ends of the hatch covers along with structure 70 including the plurality of metal straps 71. Toward their lower or distal ends, the side sections 104, 106 and 144, 146 of the end pieces 100 and 140 (FIG, 8), respectively, along with the lower or distal ends of the side sections of the metal straps 71 (
In one form, and as shown in
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, this invention disclosure merely sets forth an exemplification of the invention disclosure and is not intended to limit the invention disclosure to the specific embodiment 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.