Low-profile hatch cover for railroad tank cars

Abstract

A vented hatch cover for covering a hatch of a railroad car can include a plurality of intake vents that communicate with a comment discharge vent. To seal against the hatch coaming of the railroad car, the vented hatch cover includes an annular gasket groove that radially separates the intake vents from the common discharge vent. To establish fluid communication between the intake vents and the common discharge vent, the vented hatch cover can define one or more radial airflow passageways configured to provide a low profile and reduce the height of the vented hatch cover.

Description

Attorney Docket No. 0024038-0002741LOW-PROFILE HATCH COVER FOR RAILROAD TANK CARSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application is related to and claims the benefit of priority of U.S. provisional application no. 63 / 719,778, field on November 13, 2024, the entire contents of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present invention is related to hatch covers for railroad tank cars and, more particularly, to a low-profile hatch cover for railroad tank cars.BACKGROUND

[0003] Railroad hopper cars carrying bulk particulate matter, such as grain or plastic pellets, are typically unloaded by applying a vacuum conveying line to an outlet gate positioned at the bottom of each car compartment. The primary airflow for the vacuum conveying line is obtained exteriorly of the railroad car to draw the materials therefrom. However, as content is removed from the railroad, it is necessary to vent the top of the car compartment to compensate for material drawn out the bottom of the compartment. Failure to vent the top of the compartments of the railroad car can reduce the efficiency of the vacuum unloading process and even risk damage to the car structure due to the resulting counter-suction generated by the removal of contents from the railroad hopper cars.

[0004] Conventionally, venting can be accomplished by opening the hatch covers installed on the top of the railroad cars to allow for airflow into the compartments during unloading, but this venting process presents disadvantages. For example, an operator must climb to the top of the railroad car to access and open the hatch covers. Once the hatch covers are opened, there is the possibility of contaminants or precipitation entering through the uncovered hatchway opening and contaminating the contents of the railroad car. Moreover, the hatch covers must be maintained in the opened configuration during unloading.

[0005] Accordingly, vented hatch covers may be used that allow for airflow from the surrounding environment into the compartments during unloading. The vented hatch cover mayAttorney Docket No. 0024038-0002742include vent openings that communicate with the interior of the railroad car through an airflow passageway defined by the structure of the hatch cover. An example of a vented hatch cover assembly is described in U.S. Patent No. 7,703,630, assigned to Salco Products, Inc. of Lemont Illinois. The ’630 patent describes assembly of a vented hatch cover having a molded body that defines an enclosed airflow passageway there through for directing airflow into the railroad hopper car from the environment. The present disclosure is directed to the design and construction of a vented hatch cover that can be assembled from a plurality of injection molded parts to form an airflow passageway having an advantageous shape and volume.SUMMARY

[0006] The arrangement of the present disclosure provides, in an aspect, a vented hatch cover for a hatch on a railroad hopper car of the type including an upright cylindrical coaming defining a hatch opening. The vented hatch cover can include an interior plate including an annular gasket channel concentric about a central hatch axis, a first intake vent and a second intake vent, an annular gasket channel, and a common discharge vent circumscribed by the annular gasket channel. The vented hatch cover also includes a first exterior shell attachable to the interior plate to define a first radial airflow passageway between one of the intake vents and the common discharge vent and a second exterior shell attachable to the interior plate to define a second radial airflow passageway between one of the intake vents and the common discharge vent.

[0007] In a further aspect, the interior plate includes a first duct frame and a second duct frame that are laterally opposite and directly radially toward the common discharge vent.

[0008] In further aspect, the first exterior shell attaches to the first duct frame to provide a first radial airflow passageway and the second exterior shell attaches to the second duct frame to provide a radial airflow passageway.

[0009] In a further aspect, the first intake vent and the second intake vent are rectangular and tangential to a circular periphery circumscribing the annular gasket channel.

[0010] In another aspect of the disclosure, there is described a vented hatch cover including an interior plate including an annular gasket channel concentric about a central hatch axis, plurality of vent intakes, an annular gasket channel and a common discharge vent circumscribed by the annular gasket channel. The vented hatch cover also includes an exterior cover shellAttorney Docket No. 0024038-0002743attachable to the interior plate to define at least one radial airflow passageway between the plurality of intake vents and the common discharge vent.

[0011] In a further aspect, the interior plate includes a duct wall delineating the radial airflow passageway and the exterior cover shell attached to an edge of the duct wall.

[0012] In a further aspect, the duct wall defines a non-regular pentagonal converging toward the central hatch axis.

[0013] In a further aspect, the plurality of vent intakes each includes a rectangular vent fixture configured to attach with a corresponding rectangular intake screen fixture.

[0014] In a further aspect, the exterior cover shell is laser welded to an edge of the duct wall.

[0015] In a further aspect, the common discharge vent includes a cross-bracing defining four quadrant openings.

[0016] In a further aspect, the common discharge vent includes a circular discharge bracing that protrudes axially with respect to a hatch center.

[0017] In a further aspect, the circular discharge bracing is configured to releaseably attach with a discharge screen fixture.

[0018] In further aspect, the discharge screen fixture includes a screen disk and a peripheral rim extending normal to the screen disk, the peripheral rim configured to create an annular fit with a vent fixture.

[0019] In further aspect, the annular gasket channel is a C-channel having an outer channel edge and an inner channel edge that are parallel to the central hatch axis and an annular channel seat between the outer channel edge and the inner channel edge normal to the central channel axis.

[0020] In another aspect of the disclosure, there is describe a vented hatch cover that includes an exterior shell comprising a planar axial face that is circular and aligned to a central hatch axis and a peripheral sidewall that extends normally from the planar axial face. The vented hatch cover also includes an interior plate including a peripheral edge that is configured to fit within the peripheral sidewall, an annular gasket channel, a plurality of angularly spaced intake vents located between the peripheral edge and the annular gasket channel, and at least one interior discharge vent encircled by the annular gasket channel.Attorney Docket No. 0024038-0002744

[0021] In a further aspect, the vented hatch cover has the peripheral edge and the peripheral sidewall configured to form a snap-fit to connect the exterior shell and the interior plate.

[0022] In a further aspect, the vented hatch cover has the annular gasket channel configured as a C-channel including an outer channel edge and inner channel edge that extend normally from an annular gasket seat.

[0023] In a further aspect, the annular gasket seat is spaced apart from a planar inner surface of the planar axial face to provide an intake to define a radial airflow passageway between the plurality of intake vents and the interior discharge vent.

[0024] In a further aspect, the plurality of angularly spaced intake vents circumscribe the annular gasket channel.

[0025] In a further aspect, the plurality of angularly spaced intake vents are located within an annular intake bracing that encircles the annular gasket channel.

[0026] In a further aspect, the plurality of angularly spaced intake vents are axially coplanar with the annular gasket seat.

[0027] In a further aspect the plurality of angularly spaced intake vents are located axially below the peripheral sidewall.

[0028] In a further aspect, the planar axial face includes a planar outer surface opposite a planar inner surface.

[0029] In a further aspect, the exterior shell includes a linear groove diametrically traversing the planar axial face.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a perspective view of a railroad hopper car having plurality of vented hatch covers disposed along the top to vent the internal compartments to the atmosphere.

[0031] Figure 2 is a top perspective view of a vented hatch cover assembled from an interior plate and a pair of diametrically opposed exterior shells mounted to define a pair of radial airflow passageways laterally opposite of an over-center locking arm.

[0032] Figure 3 is a bottom perspective view of the vented hatch cover showing the internal plate having an annular gasket channel, a pair of diametrically opposite intake vents, and a discharge vent fluidly communicating through a pair of radial airflow passageways.Attorney Docket No. 0024038-0002745

[0033] Figure 4 is a top assembly view of the internal plate separated from the exterior shells to show the extended duct walls delineating the radial airflow passageways.

[0034] Figure 5 is a bottom assembly view of the internal plate having a pair of laterally opposed intake vents and a common discharge vent with an annular gasket channel located there between.

[0035] Figure 6 is an elevational cross-sectional view schematically showing airflow from the intake vent through the radial airflow passageway to the discharge vent.

[0036] Figure 7 is a cross-sectional perspective view of the vented hatch cover showing the intake screen associated with an intake screen fixture and the discharge vent associated with a discharge screen fixture.

[0037] Figure 8 is perspective view of the intake screen fixture that is rectangular in shape and configured to attach with an intake vent bracing via fasteners.

[0038] Figure 9 is a perspective view of the discharge screen fixture that is circular in shape and configured to attach with a discharge vent bracing by an annular fit.

[0039] Figure 10 is a top perspective view of a vented hatch cover assembled from an interior plate and a single exterior shell mounted thereon to define a pair of radial airflow passageways.

[0040] Figure 11 is a bottom perspective view of the vented hatch cover showing the interior plate assembled in the exterior shell.

[0041] Figure 12 is a top perspective view of a vented hatch cover assembled from an exterior shell having a peripheral sidewall accommodating an interior plate.

[0042] Figure 13 is a bottom perspective view of the vented hatch cover of FIG. 12 showing a plurality of angularly arranged radial intake vents axially below the peripheral sidewall and a common discharge vent in the interior plate.

[0043] Figure 14 is an elevational cross-sectional view schematically showing the airflow from the radial intake vents to the common discharge vent.

[0044] Figure 15 is a top perspective view of another embodiment of the vented hatch cover assembled from an exterior shell having a peripheral sidewall and an interior plate.Attorney Docket No. 0024038-0002746

[0045] Figure 16 is a bottom perspective view of the vent hatch cover of Figure 15 showing a plurality of angularly arranged intake vents in the interior plate axially recessed with respect to the peripheral sidewall.

[0046] Figure 17 is an elevational cross-sectional view schematically showing the airflow from the radial intake vents to the common discharge vent.DETAILED DESCRIPTION

[0047] Now referring to the drawings, wherein whenever possible like reference numbers refer to like elements, there is illustrated in FIG. 1 a plurality of hatch covers 100 that are mounted over the top of a railroad hopper car 102, which is an example of one intended application for disclosure. The railroad hopper car 102 can be adapted to carry particulate materials such as plastic pellets or other granular materials that are readily displaceable. The railroad hopper car 102 can include an exterior car body 104 mounted on trucks to engage with a pair of rails. To accommodate the particulate contents, the interior defined by the car body 104 can have a plurality of interconnected partitions 106 that separate the body into a plurality of distinct compartments 108 or vessels. An advantage of separating the interior of the car body 104 into a plurality of compartments 108 is to better distribute weight within the car body 104 and to facilitate unloading of the contents. For unloading, each compartment can include a slanted bottom surface 110 that directs the particulate matter to a respective outlet gate 112 at the bottom of the railroad hopper car 102. Per conventional design, the car body 104 and the interconnected partitions 106 can be manufactured of structural metal plates and panels for rigidity and durability.

[0048] To load the railroad hopper car 102, a plurality of hatches 114 are located along the roof of the car body 104 and may be aligned with respect to the length of the car body. One or more hatches 114 can be associated with each of the compartments 108 defined within the interior of the car body 104. Each hatch 114 can include a cylindrical coaming 116 that extends upwardly from the roof of the car body 104 and that defines a circular hatch opening 118 into the respective compartment. To abut against the hatch cover 100, the upper edge or rim of the cylindrical coaming 116 can be folded radially outward to provide a flange or the like. By way of example, the diameter of the cylindrical coaming 116 may be approximately 20 inches, whichAttorney Docket No. 0024038-0002747defines the outer diameter of the hatch opening 118. The cylindrical coaming 116 can be made of the same rigid metal material as the car body 104.

[0049] To cover and seal the hatch openings 118, each of the plurality of hatches 114 is associated with one of the respective vented hatch covers 100. The vented hatch covers 100 can be pivotally attached with respect to the roof of the car body 104 to tilt and articulate with respect to the cylindrical coamings 116, and can thereby selectively open the hatch openings 118 for loading and close the openings 118 to prevent the unintended entry of contaminants into the compartments 108. The vented hatch cover 100 can be durably constructed and assembled for repeatedly opening and closing the hatches 114 by making sealing contact with the upward extended cylindrical coaming 116.

[0050] Referring to FIGS. 2 and 3, to produce the vented hatch cover 100 within the desired shape and size constraints imposed by its intended use on a railroad hopper car, the vented hatch cover 100 may be multicomponent assembly including, for example, an thermoplastic interior plate 120 and a pair of exterior cover shells 122, 124 that are mounted exteriorly of the thermoplastic interior plate 120. The thermoplastic interior plate 120 and the exterior cover shells 122, 124 can be injection molded as thin-walled structures from a thermoplastic material by injection molded plastic to assume the contours, shapes, and thin-wall configuration to delineate airflow passageway. For example, the pair of exterior shells 122, 124 can be associated with a corresponding pair of air intake ducts that direct airflow to the railroad car from the exterior atmosphere. The vented hatch cover 100 may be referred to as a dual vented design.

[0051] To enable the vented hatch cover 100 to pivotally articulate with respect to the railroad car between opened and closed positions, the thermoplastic interior plate 120 can be mounted to an over-center locking arm 126 such as described in U.S. Patent 4,819,830, herein incorporate by reference in its entirety. The elongated locking arm 126 can be pivotally connected by a hinge 128 at one end to the roof of the railroad car and can extend across the diameter of the injection molded thermoplastic interior plate 120 to latch 129 at the other end that is configured to connect and lock with a corresponding catch mechanism on the railroad car. The over-center arrangement of the locking arm 126 locates the elongated structure between the first and second injection molded exterior shells 122, 124 associated with the air intake ducts. The elongated locking arm 126 can be fixedly secured to the injection molded thermoplasticAttorney Docket No. 0024038-0002748interior plate 120 by fasteners, for example, such that when the locking arm 126 is pivoted about the hinge 128 the vented hatch cover 100 is tilted with respect to the hatch on the railroad car. For durability and weather resistance, the elongated locking arm 126 can be made from metal bar stock.

[0052] Referring to FIGS. 4 and 5, the thermoplastic interior plate 120 can be a molded thermoplastic structure having a circular hatch frame 130 defined by a circular hatch periphery 132 shaped and dimensioned to overlay the hatch of the railcar and a pair of laterally opposed intake duct frames 134, 136 extending from the circular hatch periphery 132. The circular hatch frame 130 can be aligned with respect to a hatch center point or central hatch axis 138, and the intake duct fames 134, 136 can extend in opposite radial directions with respect to the central hatch axis 138. The intake duct frames 134, 136 can be structurally identical and arranged in a mirrored relation to each other across the diameter of the circular hatch frame 130.

[0053] The circular hatch frame 130 and the opposed pair of intake duct frames 134, 136 can be integrally molded as a common thermoplastic part. Example of a suitable molding processes to produce the detailed structural features of the thermoplastic interior plate 120 can include injection molding and vacuum molding. Suitable thermoplastic materials include ABS, HDPE, and others.

[0054] The circular hatch frame 130 and the intake duct frames 134, 136 can structurally cooperate to define a first radial airflow passageway 140 and a second radial airflow passageway 142 that receives and directs air from beyond the circular hatch periphery 132 radially towards the central hatch axis 138. The first and second radial airflow passageways 140, 142 (indicated by arrows) can be defined between separate respective air intake vents 144, 146 located in the intake duct frame 134, 136 and a common air discharge vent 148 located within the center of the circular hatch frame 130 and aligned with the central hatch axis 138. The first and second radial airflow passageways 140, 142 are therefore oppositely directed with respect to the central hatch access 138 and the common discharge vent 148.

[0055] To receive air from the atmosphere, the first and second air intake vents 144, 146 can be rectangular apertures or openings formed in the respective first and second intake duct frame 132, 134 that are arranged tangential to the circular hatch periphery 132 of the circular hatch frame 130. The rectangular first and second intake vents 144, 146 can be parallel to each otherAttorney Docket No. 0024038-0002749and can be outlined by correspondingly shaped rectangular intake bracings 150. The intake bracings 150 can each have a continuous thin- walled structure extending in the axial direction 138 with respect to the central hatch axis 138.

[0056] The intake duct frames 134, 136 can each also include a respective duct wall 152 also formed as a thin-walled structure extending in the opposite axial direction from the intake bracings 150. The duct walls 152 are shaped to outline and define the first and second radial airflow passageways 140, 142 extending radially inward from the first and second air intake vents 144, 146 to the common discharge vent 148. The duct walls 152 may extend across the circular hatch periphery 132 and partially over the circular hatch frame 130. The duct walls 152 can extend at least partially around and fluidly interconnect the air intake vents 144, 146 and the discharge vent 148.

[0057] Referring to FIG. 4, the duct walls 152 can shaped to correspond to the pair of exterior cover shells 122, 124. In an embodiment, the duct walls 152 and the exterior cover shells 122, 124 can be shaped as irregular five-sided pentagons. The longer base of the pentagonal duct walls 152 can be associated with the rectangular air intake vents 144, 146 and the remaining sides can converge towards the common air discharge vent 148 as the duct walls 152 extend radially toward the central hatch axis 138. The convergence of the duct walls 152 can function to direct and concentrate the airflow in the radial airflow passageways 140, 142 from the air intake vents 144, 146 toward the common air discharge vent 148.

[0058] To enclose the radial airflow passageways 140, 142, the first and second exterior cover shells 122, 124 can each have a five-sided shell perimeter 154 that corresponds in shape to the irregular profile of the duct walls 152. The exterior cover shells 122, 124 can be flat, planer pieces or sheets of plastic of plastic molded or stamped to the outline defined by the duct walls 152. An example of a suitable manufacturing process for the exterior cover shells can be vacuum molding in which a sheet of plastic is clamped in a frame, heated and a vacuum is applied to conform the plastic sheet to displace and conform to the structural details of the frame. The shell perimeters 154 of exterior cover shells 122, 124 can adjacently overlap and be abuttingly joined on top of the upper edges of the duct walls 152. The exterior cover shells 122, 124 can be joined to the upper edges of the duck walls 152 by a suitable method such a laser welding, ultrasonic welding, and the like that may form a sealed joinder of the structures. AAttorney Docket No. 0024038-00027410laser beam can be moved about the abutting edges of the shell perimeters 154 and the duct walls 152 to melt and fuse together to form an integral structure.

[0059] The flat planar shape of the exterior cover shells 122, 124 are orthogonal to the central hatch axis 138 and provide the hatch cover 100 with a flat low profile in the axial direction reducing the height of the hatch cover. Referring to FIG. 2, the over-center locking arm 126 can be situated within a gap formed between the parallel and spaced-apart linear edges of the duct walls 152 and of the shell perimeters 154 that extend laterally to either side of the central hatch axis 138.

[0060] The common discharge vent 148 can be located in the circular hatch frame 130 and encircled by the circular hatch periphery 132. To establish and define the common discharge vent 148, the circular hatch frame 130 can include a circular discharge bracing 156 that is concentrically aligned about the central hatch axis 138. The circular discharge bracing 156 can be structurally configured as a circular embossment, located radially within and concentrically circumscribed by the circular periphery 132 and that projects axially downward with respect to the central hatch axis 138.

[0061] The circular hatch frame 130 can also include a cross bracing 158 that extends across the common discharge vent 148 disposed centrally through the circular discharge bracing 156. The cross bracing 158 can be shaped as a cross with intersecting beams or legs orientated at right angles and that are directed radially outward form the central hatch axis 138. The cross bracing separates the common discharge vent 148 into four discharge openings 159 that are arranged as quadrants within the circular discharge bracing 156. The cross bracing 158 can provide structural rigidity and strength to the thermoplastic interior plate 120 that may repeatedly be shut against the cylindrical coaming of the hatches

[0062] In an embodiment, the widths or legs that form the cross-bracing 158 may have different widths or thicknesses. Referring to FIGS. 2 and 3, the thicker beam of the cross brace 158 may correspond to the location of the over-center locking arm 126 when attached to the vented hatch cover 100.

[0063] Referring to FIGS. 3 and 5, to seal the vented hatch cover 100 against the cylindrical coaming 116 when covering the hatch 114, the circular hatch frame 130 can include and structurally define an annular gasket channel 160 that is adapted to receive an elastomeric gasketAttorney Docket No. 0024038-00027411170 or seal. The annular gasket channel 160 is concentrically located between the circular hatch periphery 132 and the circular discharge bracing 156 and aligned with respect to the central hatch axis 138. The annular gasket channel 160 forms a continuous ring or circle structurally defined by the body of the circular hatch frame 130.

[0064] In an example shown in FIGS. 6 and 7, the annular gasket channel 160 can be structurally formed as a c-channel including thin-walled flanges or channel edges that extend in the axial direction with respect to the central hatch axis 138. For example, the gasket channel 160 can include a circular outer channel edge 162 that is circumferentially coextensive and structurally correspond with the circular hatch periphery 132 and an inner channel edge 164 that is spaced radially inward of and concentric with the outer channel edge 162. The inner channel edge 164 can be coextensive and structurally correspond to the circular discharge bracing 156 associated with the common discharge vent 148.

[0065] The annular gasket channel 160 can also include an annular channel seat 166 or web that extends between the outer and inner channel edges 162, 164. The annular channel seat 166 is therefore situated in a plane normal or orthogonal to the central hatch axis 138. Referring to FIGS. 4, the annular channel seat 166 can be located within the first and second radially airflow passageways 140, 142 and can intersect the duct walls 152. To avoid occulting the first and second radial airflow passageways 140, 142, the duct walls 152 can extend axially above the annular channel seat 166 at the intersection of the structures.

[0066] The distance between and separating the outer and inner channel edges 162, 164 creates an annular gap that can receive an elastomeric or rubber gasket or seal. The annular gasket channel 160 defined between the outer and inner channel edges 162, 164 can correspond in dimension and location with the cylindrical coaming 116 of the hatch. For example, the circular centerline between the outer and inner channel edges 162, 164 can be approximately 20 inches in diameter so that the gasket channel 160 will align with the cylindrical coaming 116 when the vented hatch cover 100 is pivoted over to cover the hatch.

[0067] Referring to FIGS. 6 and 7, an annular gasket 170 can be adapted to be received within the annular gasket channel 160 to seal against the cylindrical coaming of the hatch. The annular gasket 170 can be made of a compressible elastomeric material such as a thermoset or thermoplastic elastomer. The compressible elastomeric material of the annular gasket 170 can beAttorney Docket No. 0024038-00027412comparatively flexible and pliable with respect to the rigid structure of the thermoplastic interior plate 120 of the vented hatch cover 100. Examples of gasket material may include silicone rubber or ethylene propylene diene monomer rubber (EPDM). The rubber material may be extruded through a die into a linear gasket segment having a desired cross-section.

[0068] Extrusion can provide the annular rubber gasket 170 with a specific profile to facilitate sealing and retention in the annular gasket channel 160. For example, the annular rubber gasket 170 can include a pair of outer gasket edges 172 and a pair of intermediate gasket ribs 174 that project orthogonally from a gasket web 176. The pair of outer gasket edges 172 and the intermediate gasket ribs 174 may be parallel to each other and may curve in extension to conform to the annular shape of the annular rubber gasket 170. The gasket web 176 can provide a planar, axially oriented, annular surface having elastomeric, compressible properties. When the annular rubber gasket 170 is received in the annular gasket channel 160, the planar axial extension of the gasket web 176 is oriented axially downward to contact and abut the upward cylindrical coaming of the hatch forming a weather tight seal.

[0069] The annular rubber gasket 170 can be retained in the annular gasket channel 160 by various techniques. For example, the outer and inner channel edges 162, 164 can include protruding hooks that can partially extend over the annular rubber gasket 170. The compressible characteristics enables the annular rubber gasket 170 to be press-fit between the hooks and create a snap-fit retaining the gasket in the annular gasket channel 160. The annular rubber gasket 170 can also be retained with adhesive in annular gasket channel 160.

[0070] To prevent contaminants from entering the railroad cars, the vented hatch cover 100 can include filter or screen fixtures fitted to the thermoplastic interior plate 120 and located or in fluid communication with the first and radial airflow passageways 140, 142. For example, referring to FIGS. 3, 6, and 9, an intake screen fixture 180 can be attached to each of the first and intake vents 144, 146. The intake screen fixture 180 can have an elongated rectangular shape complementary to and is adapted to be received in the rectangular intake bracings 150 associated with the first and second intake duct frames 134, 136.

[0071] Referring to FIG. 9, the intake screen fixture 180 can include a rectangular screen frame 182 of injection molded plastic formed from parallel longer beams interconnected by a plurality of traversely arranged shorter beams. Situated between the interconnected beams of theAttorney Docket No. 0024038-00027413rectangular screen frame 182 can be screens 184 that can be formed on an interconnected plastic mesh or lattice. The screens 184 defines a plurality of openings or perforations that allow for airflow into the respective intake vent 144, 146 while filtering larger objects such as leaves or debris. The screens 184 can be molded as part of the rectangular screen frame 182. In other embodiments, the screens 184 can be a porous filter media that is overmolded and structurally supported by the rectangular screen frame 182.

[0072] To secure the intake screen fixture 180 to the rectangular intake bracings 150 defining the first and second intake vents 144, 146, the rectangular screen frame 180 can include a plurality of tabs 186 that extend upwards from selected beams arranged around the screens 184. The tabs 186 can be thin walled plastic features integrally molded with the rectangular screen frame 180 and are arranged to slide adjacently with the surrounding rectangular intake bracing 150 when the intake screen fixture 180 is fitted into the respective intake vents 144, 146.Threaded fasteners 188, for example, self-tapping screws, can be driven through the intake bracing 150 and the plurality of tabs 186 to join the intake screen fixture 180 within the respective intake vents 144, 146.

[0073] The vented hatch cover 100 can also include a discharge screen fixture 190 that is associated with the common discharge vent 148 located in the circular hatch frame 130.Referring to FIG. 3, 6, and 10, the discharge screen fixture 190 can include a circular screen frame 192 that is complementary in shape and size to the circular discharge bracing 156 and is adapted to be fitted thereon. For example, the circular screen frame 192 can include and an annular upwards extending rim 194 configured to adjacently circumscribe and extend about the circular discharge bracing 156. The rim 194 can include a plurality of angularly spaced circumferential apertures 196 or holes disposed therein that are adapted to receive and form a snap-fit with corresponding plurality of angularly spaced tabs 198 that project radially outward from the circular discharge bracing 156. When the circular screen frame 192 is inserted over the circular discharge bracing 156, the circumferential apertures 196 and complementary tabs 198 snap together securing the discharge screen fixture 190 to the circular hatch frame 130 and adjacently across the common discharge vent 148.

[0074] To allow for air flow, the discharge screen fixture 190 can include a plurality of screens 199 arranged to correspond to the locations of the discharge openings 159. The screensAttorney Docket No. 0024038-00027414199 can be formed as a lattice or mesh with perforations or apertures allowing the passage of air through the discharge screen fixture 190. The screens 199 can be separated by a plurality of beams or chords extending between the circular screen frame 192 that may correspond in location with the cross bracing 158 of the circulate hatch frame 130. The cross bracing 158 can support and prevent the discharge screen fixture 190 from being drawn into the discharge vent 148.

[0075] Referring back to FIGS. 6 and 7, to ventilate the railroad car, airflow indicated by arrow AF can be directed from the atmosphere into the intake vents 144, 146 associated with and introduced to the radial flow passageways 140, 142 of the vented hatch cover 100. When the vented hatch cover 100 is pivoted to the closed position, the intake vents 144, 146 are oriented axially downward with respect to the central hatch axis 138 to prevent the ingress of perception. Furthermore, the intake screen fixtures 180 that may be secured in the rectangular intake bracings 150 can prevent the entry of larger debris or contaminants.

[0076] The airflow AF is redirected from the axial direction parallel with the central hatch axis 138 radially inward by the radial flow passageways 140, 142. Particularly, the exterior covers shell 122, 124 can be attached to the duct walls 152 forming the first and second intake duct frames 134, 136 to enclose the radial flow passageways 140, 142 to create an enclosed conduit that structurally directs and channels the airflow AF radially toward the central hatch axis 138. The airflow AF can be redirected axially by the circular discharge bracing 156 to discharge through the common discharge vent 148 of the circular hatch frame 130. The discharge screen fixture 190 that may be attached to the circular discharge bracing 130 can filter or prevent materials including the railroad car contents from entering or exiting the radial airflow passageways 140, 142 by entrainment in the airflow AF.

[0077] As illustrated in FIGS. 6 and 7, constructing the vented hatch cover 100 from the thermoplastic interior plate 120 and the exterior cover shells 122, 124 that are flat and planar in configuration provides the vented hatch cover with a low profile reducing its overall height. The flat exterior cover shells 122, 124 are spaced apart from the surfaces of the central hatch frame 130 by the duct walls 152 to create spacing corresponding to the radial airflow passageways 140, 142 radially directed from the first and second intake duct frames 134, 136. For example, the exterior cover shells 122, 124 can be spaced apart from the annular channel seat 166 so that theAttorney Docket No. 0024038-00027415radial airflow passageways 140, 142 fluidly interconnect the intake vents 144, 146 with the common discharge vent 148.

[0078] Referring to FIGS. 11 and 12, there is illustrated another embodiment of the vented hatch cover 200 used to selectively close hatches 114 on a railroad car 102 shown in FIG. 1. The vented hatch cover 200 can be assembled from a plurality of injection molded plastic components including a thermoplastic interior plate 220 structurally similar to the embodiment described above. For example, the thermoplastic interior plate 220 can include a circular hatch frame 230 aligned to a central hatch axis 238 and a pair of lateral opposed intake duct frames 234, 236 that extend radially outward from the circular periphery 232 of the circular hatch frame 230. The first and second intake duct frames 234, 236 can include respective first and second intake vents 244, 246 that fluidly communicate with common discharge vent 248 disposed in the circular hatch frame 230 via first and second radial airflow passageways 240, 242.

[0079] To seal against the cylindrical coaming of the hatch, the circular hatch frame 230 can structurally form an annular gasket channel 260 that is concentrically aligned with the central hatch axis 238 and can receive a compressible elastomeric gasket. To prevent containments or contents from entering the first and second radial airflow passageways 240, 242, the first and second intake vents 244, 246 and the common discharge vent 248 can be associated with the intake screen fixtures and the discharge screen fixture described above.

[0080] To enclose the first and second radial airflow passageways 240, 242 structurally defined in the thermoplastic interior plate 220, the vented hatch cover 200 can include a single exterior cover shell 280 in contrast to the embodiment described above. For example, the exterior cover shell 280 can correspond in shape to the configuration of the thermoplastic interior plate 220, including the circular hatch frame 230 and the laterally opposed first and second intake duct frames 234, 236.

[0081] The exterior cover shell 280 can include a planar axial face 282 that coextensively overlays the thermoplastic interior plate 220 and is orthogonal to the central hatch axis 238. For example, the planar exterior face 282 can include a circular face section 284 that is axially aligned with the central hatch axis 238 to correspond in location with the circular hatch frame 230 and can include a pair of laterally opposed rectangular face portions 286, 288 that correspond in location with the first and second intake duct frames 234, 236. To preventAttorney Docket No. 0024038-00027416precipitation from collecting on the exterior cover shell 280, the planar exterior face 282 including the exteriors of the circular face section 284 and / or the rectangular face portions 286, 288 may be configured with curves or a tapered configuration that causes rain water to run off.

[0082] In an embodiment, to accommodate the over-center latch arm, the circular face section 284 can have a linear groove 290 that is disposed into the body of the exterior cover shell 280 between the opposed rectangular face portions 236, 238. The linear groove 290 may cross the central hatch axis 238 and thus corresponds to the diameter of the circular face section 284.

[0083] To attach the exterior cover shell 280 with the thermoplastic interior plate 220, the exterior cover shell 280 can include a peripheral skirt 292 or sidewall that extends normally from the outer edges of the planar axial face 282. The peripheral skirt 292 can correspond to the outline of the thermoplastic interior plate 220. The peripheral skirt 292 can be axially coextensive with the circular periphery 232 of the circular hatch frame 230 and the thickness of the first and second intake duct frames 234, 236. When the thermoplastic interior plate 220 is inserted and assembled to the exterior cover shell 280, the peripheral skirt 292 surrounds and extends adjacently to the peripheral outline of the thermoplastic interior plate 220. The thermoplastic interior plate 220 and the exterior cover shell 280 can be joined by a snap-fit structure, laser welding of the plastic material, ultrasonic welding, adhesive or the line. The joinder between the thermoplastic interior plate 220 and the exterior cover shell 280 is preferably hermetically sealed.

[0084] Referring to FIGS. 12 and 13, there is illustrated an embodiment of the vented hatch cover 300 that is circular in shape to correspond to the cylindrical hatch coamings that is assembled from an exterior hatch shell 302 and an interior plate 304 are that aligned about a central hatch axis 306. The exterior shell 302, which corresponds to the exposed portion of the vented hatch cover, includes a planar axial face 310 that is circular in shape and a peripheral sidewall 312 that depends from the outer circumference of the planar axial face 310 parallel to the central hatch axis 306. To attach the vented hatch cover 300 to the over-center latch arm of the railroad car, the exterior hatch shell 302 includes a linear groove 314 that is recessed therein and that extends diametrically across the planar axial face 310 with respect to the central hatch axis 306. The recessed characteristic of the linear groove 314 can spatially accommodate the latch arm to reduce the overall height of the vented hatch cover 300 when attached to the railroadAttorney Docket No. 0024038-00027417card. Fasteners can be used to attach the vented hatch cover 300 to the locking arm. To enable rain water to run off the exterior hatch shell 302, the planar axial face 310 may be slightly tapered or curved as the structure extends to the peripheral sidewall 312.

[0085] To connect the interior plate 304 to the exterior hatch shell 302, the exterior hatch shell may include a plurality of angularly spaced shell notches 316 that are disposed through the circular corner where the planar axial face 310 and the peripheral sidewall 312 intersect. The shell notches 316 are angularly spaced around the central hatch axis 306 and can be formed as cut-outs or apertures through the material of the exterior hatch shell 302. The shell notches 316 can function as catches that receive and from a snap-fit with a corresponding plate bar 318 or hook extending radially from the interior plate 304. In other embodiments, the exterior hatch shell 302 and the interior plate 304 can be connected by other mechanisms including bonding or fasteners.

[0086] The interior plate 304 can have a circular peripheral edge 320 that is shaped and sized for reception into the exterior hatch shell 302, wherein the circular peripheral edge 320 can make sliding contact with the cylindrical inner surface of the peripheral sidewall 312. To receive air for introduction to the railroad car, the interior plate 304 can include a plurality of intake vents 322 that are angularly spaced apart with respect to the central hatch axis 306 and that are located adjacent to and radially inward of the peripheral edge 320. The intake vents 322 can be formed as cutouts or apertures formed into an annular intake bracing 324 that extends radially inward from the circular peripheral edge 320 and which may be a thin-walled structure that is normal to the central hatch axis 306. The plurality of angularly spaced intake vents 322 can be shaped as oblong oval that are curved to correspond to the circular peripheral edge 320.

[0087] In an embodiment, the plane of the annular intake bracing 324 can be axially coextensive or spaced slightly below the axial location of the lower extension of the peripheral sidewall 312 with respect to the central hatch axis 306. Further, the annular intake bracing 324 can have a larger diameter than the corresponding hatch coaming on the railroad car which the hatch cover assembly 300 will be operatively associated. For example, the hatch coaming may be 20” in diameter and the annular intake bracing 324 is designed to circumscribe peripherally about and to overhang the hatch coaming, thus having a larger diameter. The plurality ofAttorney Docket No. 0024038-00027418angularly spaced intake vents 322 are radially external of the hatch coaming and exposed to received intake air from the atmosphere.

[0088] To seal against the hatch coaming, the vented hatch cover 300 can include an annular gasket channel 330 to receive a correspondingly shaped an annular elastomeric or rubber gasket as described herein. The annular gasket channel 330 can be configured as a C-channel having inner and an outer flanges or channel edge 332, 334 extending in the axial direction and an annular shaped channel web or gasket seat 336 that extends between the channel edges 332 normal to the central hatch axis 306. The annular gasket channel 330 can be oriented axially downward with respect to the central hatch axis 306 and can having a plurality of radially directed barbs or clips 338 that project into the channel to retain the annular gasket or seal. Moreover, the annular gasket channel 330 can be approximately 20 inches in diameter to coextensively overlie a correspondingly dimensioned hatch coaming.

[0089] To discharge the intake air into the railroad car, the vented hatch assembly can include a common discharge vent 340 that corresponds generally to the center of the interior plate 304 and is located radially inward of the annular gasket channel 330. The common discharge vent 340 can be defined in a circular discharge bracing 342 which may be a thinwalled structure normal to the central hatch axis 206 and that is connected to a distal end of the inner channel edge 334 to form a right angled intersection or comer. The circular discharge bracing 342 can include one or more cut-outs or apertures that are arranged as quadrants and that can be operatively associated with discharge screens 344 that may be formed as a formed as a lattice or mesh with perforations.

[0090] Referring to FIG. 14, when the exterior hatch shell 302 and the interior plate 304 are assembled together, for example by a snap-fit, the structures may be partially spaced apart with respect to the central hatch axis 306 to create one or more radially airflow passageways 346. For example, the radial airflow passageway 346 can be located between the web or channel seat 336 of the annular gasket channel 330 and the interior surface of the planar axial face 310. In operation, airflow indicated by arrow AF can be directed from the atmosphere axially into the angularly spaced intake vents 322 disposed in the interior plate 304 to encounter the inner surface of the planar axial face 310 of the exterior hatch shell 302. The airflow AF is redirectedAttorney Docket No. 0024038-00027419radially inward through the radially airflow passageway 336 between the flat axial face 310 and the gasket seat 336 to reach the common discharge vent 340 for introduction into the railroad car.

[0091] An advantage of the foregoing is that the vented hatch cover 300 has a relatively low profile when used on a railroad car. For example, referring to FIG. 12, the vented hatch cover 300 has a hatch height 350 between the planar axial face 310 of the exterior hatch shell 302 and the circular discharge bracing 342 of the interior plate 304 that is less than 2 inches. Moreover, because a substantial portion of the axial extension of the vented hatch cover 300 is received inside the hatch coaming when the vent hatch cover 300 is closed, the vented hatch cover 300 can have a closed hatch height 352 between the planar axial face 310 and the channel seat 336 of the annular gasket channel 330 that may be less than 1 inch. The actual height that the vented hatch cover 300 protrudes above the hatch coaming is likely to be between the two height values, and thus the overall profile of the vented hatch cover 300 is low.

[0092] Referring to FIGS. 15 and 16, there is illustrated another embodiment of a circular hatch cover 400 that can be assembled from an exterior hatch shell 402 and an interior plate 404 that are circular in shape and co-aligned with a central hatch axis 406. The exterior hatch shell 402 can include a planar axial face 410 and a peripheral sidewall 412 depending therefrom that are concentric to the central hatch axis 406. To prevent precipitation from collecting on the exterior hatch shell 402 by allowing such to run off, the planar axial face 410 can be curved or tapered between the central hatch axis 406 and the peripheral sidewall 412. The interior plate 404 can be received in the exterior hatch shell 402 by a snap fit mechanism and can include a peripheral edge 420 that is complementary to the inner surface of the peripheral sidewall 412. Radially adjunct to the peripheral edge 420 is a plurality of intake vents 422 that are angularly space around the central hatch axis 406 and that are into an annular intake bracing 424 oriented normal to the central hatch axis 406.

[0093] To accommodate the annular elastomeric gasket described herein, the interior plate 404 includes an annular gasket channel 430 that may be configured as a three-sided C-channel having opposite channel flanges or edges 432, 434 vertically aligned and parallel with the central hatch axis 306 and an annular channel seat 436 that is normal to the central hatch axis 406. The central portion of the interior plate 302 remain structurally open and unobstructed to define a circular discharge vent 340 that is aligned to the central hatch axis 406. Accordingly, the interiorAttorney Docket No. 0024038-00027420r plate 404 may have an annular shape including the annular intake bracing 424 and the annular gasket channel 330.

[0094] Referring to FIG. 17, the planar axial face 410 of the exterior hatch shell 302 and annular gasket channel 430 of the interior plate 304 are spaced apart to provide an airflow passageway 446 establishing fluid communication between the angularly spaced intake vents 422 and the common discharge vent 440 for the airflow as indicated by arrow AF. The vented hatch cover 400 also has a low profile configuration including a first hatch height 450 between the planar axial face 410 and the circular discharge bracing 442 that is less than 2 inches. The vented hatch cover 400 can also have closed hatch height 452 between the planar axial face 410 and the channel seat 446 of the annular gasket channel 430 that may be less than 1 inch.

[0095] In a variation, the vented hatch cover 400 can have the plurality of annularly spaced intake vents 422 recessed with respect to the peripheral sidewall 412 of the exterior hatch shell 402. For example, referring to FIG. 15, the annular intake bracing 424 that defines the plurality of intake vents 422 can be axial coextensive, i.e., located in a common axial plane normal to the central hatch axis 406, with the annular channel seat 436. The intake vents 422 are therefore axially recessed between the peripheral sidewall 420 and the outer channel edge 432 of the annular gasket channel 430, that prevent the ingress of debris like leaves into the railroad car.

[0096] In another variation, to prevent the vented hatch cover 400 from collapsing over the course of repeated use, for example, the structural deformation of the annular gasket channel 430, the interior surface of the exterior hatch shell 402 can include one or more radial ribs 448 that are thin-wall structures descending axially from the exterior hatch cover shell. The radial ribs 448 can extend to abut against the inner channel edge 434 for support of the annular gasket channel 430 and may correspond in location with the common discharge vent 440.

[0097] The assemblies and arrangements disclosed herein and the processes carried out thereon include various well known components, features and operating parameters commonly associated railroad hopper cars and the transportation of granular materials and plastic pellets for example. Though not specifically discussed, or shown in the accompanying drawings, these elements are considered inherent to the disclosure and fully understood by persons of ordinary skill in the art.Attorney Docket No. 0024038-00027421

[0098] The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0099] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

Attorney Docket No. 0024038-00027422CLAIMS:

1. A vented hatch cover, comprising:an interior plate including an annular gasket channel concentric about a central hatch axis;a first intake vent and a second intake vent;an annular gasket channel;a common discharge vent circumscribed by the annular gasket channel;a first exterior shell attachable to the interior plate to define a first radial airflow passageway between the first and / or the second intake vent and the common discharge vent; anda second exterior shell attachable to the interior plate to define a second radial airflow passageway between the first and / or the second intake vent and the common discharge vent.

2. The vented hatch cover of claim 1, wherein the interior plate includes a first duct frame and a second duct frame that are laterally opposite and directly radially toward the common discharge vent.

3. The vented hatch cover of claim 2, wherein the first exterior shell is attachable to the first duct frame to provide a first radial airflow passageway and the second exterior shell is attachable to the second duct frame to provide a radial airflow passageway.

4. The vented hatch cover of claim 1, wherein the first intake vent and the second intake vent are rectangular and tangential to a circular periphery circumscribing the annular gasket channel.

5. A vented hatch cover, comprising:Attorney Docket No. 0024038-00027423an interior plate including an annular gasket channel concentric about a central hatch axis;a plurality of vent intakes;an annular gasket channel;a common discharge vent circumscribed by the annular gasket channel; an exterior cover shell attachable to the interior plate to define at least one radial airflow passageway between the plurality of intake vents and the common discharge vent.

6. The vented hatch cover of claim 5, wherein the interior plate includes a duct wall delineating the radial airflow passageway and the exterior cover shell attached to an edge of the duct wall.

7. The vented hatch cover of claim 6, wherein the duct wall defines a non-regular pentagonal converging toward the central hatch axis.

8. The vented hatch cover of claim 5, wherein the plurality of vent intakes each includes a rectangular vent fixture configured to attach with a corresponding rectangular intake screen fixture.

9. The vented hatch cover of claim 6, wherein the exterior cover shell is laser welded to an edge of the duct wall.

10. The vented hatch cover of claim 5, wherein the common discharge vent includes a crossbracing defining four quadrant openings.

11. The vented hatch cover of claim 5, wherein the common discharge vent includes a circular discharge bracing that protrudes axially with respect to a hatch center.Attorney Docket No. 0024038-0002742412. The vented hatch cover of claim 11, wherein the circular discharge bracing is configured to releaseably attach with a discharge screen fixture.

13. The vented hatch cover of claim 12, wherein the discharge screen fixture includes a screen disk and a peripheral rim extending normal to the screen disk, the peripheral rim configured to create an annular fit with a vent fixture.

14. The vented hatch cover of claim 5, wherein the annular gasket channel is a C-channel having an outer channel edge and an inner channel edge that are parallel to the central hatch axis and an annular channel seat between the outer channel edge and the inner channel edge normal to the central channel axis.

15. A vented hatch cover, comprising:an exterior shell comprising a planar axial face that is circular and aligned to a central hatch axis and a peripheral sidewall that extends normally from the planar axial face;an interior plate including a peripheral edge that is configured to fit within the peripheral sidewall;an annular gasket channel; anda plurality of angularly spaced intake vents located between the peripheral edge and the annular gasket channel.

16. The vented hatch cover of claim 15, further comprising at least one interior discharge vent encircled by the annular gasket channel.

17. The vented hatch cover of claim 15, wherein the peripheral edge and the peripheral sidewall are configured to form a snap-fit to connect the exterior shell and the interior plate.Attorney Docket No. 0024038-0002742518. The vented hatch cover of claim 15, wherein the annular gasket channel is configured as a C-channel including an outer channel edge and inner channel edge that extend normally from an annular gasket seat.

19. The vented hatch cover of claim 18, wherein the annular gasket seat is spaced apart from a planar inner surface of the planar axial face to provide an intake to define a radial airflow passageway between the plurality of intake vents and the interior discharge vent.

20. The vented hatch cover of claim 15, wherein:the plurality of angularly spaced intake vents circumscribe the annular gasket channel;the plurality of angularly spaced intake vents are located within an annular intake bracing that encircles the annular gasket channel;the plurality of angularly spaced intake vents are axially coplanar with the annular gasket seat; orthe plurality of angularly intake vents are located axially below the peripheral sidewall.

21. The vented hatch cover of claim 15, wherein the planar axial face includes a planar outer surface opposite a planar inner surface.

22. The vented hatch cover of claim 15, wherein the exterior shell includes a linear groove diametrically traversing the planar axial face.

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