Abstract:
A liquid containment device for capturing and retaining any liquid falling into the device, such as from a leak, spill or run-off of another liquid container, where the device is designed to fit between the parallel rails of a railroad track with a railroad car positioned above, comprising a generally rectilinear pan or tray and a removable cover which directs rain water into a drain opening which corresponds to an apertured drain column rising from the bottom of the pan, such that with the cover in place rain water is directed into the drain column and passed underneath the pan rather than into the pan itself. Multiple pans may be connected in line through connector fittings in their end walls, or drain conduits may be connected to the fittings for removal of the liquid from the pan. Apertured grating members and absorbent mats may be placed within the pans. The pans may be used in conjunction with lateral pans positioned on the outside of the rails.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of capture or containment devices used to capture and retain liquids, particularly leaks or spills from other containers, where the capture device is provided with a removable cover when not in use. More particularly, the invention relates to such devices which are primarily designed for outdoor use, where the cover is used to prevent rain water from entering the capture device. Even more particularly, the invention relates to such devices which are designed for placement in the center of a railroad track to capture liquids falling from railroad cars positioned above the devices. 
     It is often desirable to provide a liquid containment device beneath liquid containers or beneath areas where liquids are being sprayed or used, so that any liquid, whether from spills, leaks, run-offs or the like, is captured and retained by the containment device rather than allowing it to fall onto the floor or ground. This is especially desirable when the liquid is environmentally hazardous to the extent that non-containment can result in contaminated soil or water supplies, hazardous conditions for people or animals, etc. One such situation where it is most desirable to capture liquid leaks or spills to prevent ground contamination and fouling are railroad transfer stations, such as a rail siding where tanker cars are loaded, unloaded or cleaned. 
     A known solution is to provide a generally rectangular capture tray or pan which is sized to fit between the parallel rails making up a single track, the tray having short vertical side walls. Because the tray will capture hazardous materials such as chemicals, oil, grease, etc., the tray is preferably provided with a removable or translatable cover to prevent rain water from entering the tray when the tray is not in use. This precludes the possibility of a heavy rainfall amount filling the tray to reduce the available volume of the pan and ultimately washing over the side walls, which would disperse any hazardous liquids into the environment. Examples of such devices can be seen in U.S. Pat. No. 4,651,887 to Patrick, U.S. Pat. No. 5,435,458 to Bishop, U.S. Pat. No. 5,492,158 to Haag and U.S. Pat. No. 5,775,869 to Bishop. The Patrick patent shows a rectangular structure having a centrally located drain and a hinged drain surface, the surface being made of two planar members joined along the center line by a hinge. The surface can be disposed above the horizontal such that the two members define an elevated ridge line or peak, in which case liquid such as rain water will be directed over the side walls, or the surface may be disposed below the horizontal such that the two members define an inwardly sloping configuration such that hazardous liquid will be directed into the drain. The Bishop &#39;458 patent shows a system comprising a central rectangular capture tray positioned between the rails, the central tray having a peaked cover, i.e., sloping to either side from a central elevated ridge line, which is translated in the direction parallel to the rails to uncover the central tray for use. Exterior rectangular trays are positioned to the outside of each rail, the exterior trays having a pair of hinged covers which provide a peaked central ridge line in the closed configuration. One of the hinged covers opens to cover rail area adjacent the exterior tray and the other opens outward, such that liquids which fall onto the opened covers are directed into the exterior trays. When the trays are not in use and the covers are in place, rain water is directed to the sides of the trays. The Haag patent discloses a system of rectangular trays which utilize absorbent pads retained within and overlapping adjoining trays. Haag does not discuss the use of covers. The Bishop &#39;869 patent shows a central tray positioned between the rails with a pair of hinged covers showing a peaked central ridge in the closed configuration, where the covers open outward to extend beyond the rails laterally to capture and direct liquids into the tray. The tray has a stepped configuration such that its side edges are seated on top of the rails themselves. This device cannot be left in place between uses, since the device overrides the rails and prevents movement of the rail cars. Instead the device must be placed by fork lift under a rail car after it is moved into position and must be removed by a fork lift before the rail car can be removed. A problem with the Bishop &#39;458 device is that the rail car must be correctly positioned relative to the trays so that the wheels do not interfere with the opening of the covers, which can only be accomplished after the rail car is in place as the covers overlie the rails. The main problem with the Patrick device is that the top of the drain surface will quickly become covered in oil, grease or other hazardous chemicals, which will be washed from the surface into the environment with each rainfall. 
     It is an object of this invention to provide a capture or containment pan or tray device which collects liquids falling from above the pan to prevent environmental damage, where the tray is provided with a removable cover having an inverted or valley configuration such that the cover directs rain water into a centrally located drain which directs the water beneath the pan. It is a further object to provide such a device where the side walls of the pan do not interfere with the movement of rail cars when the device is positioned between the parallel rails of a railroad track, such that sealing gasket members can be placed between the side walls of the pan and the rails themselves to preclude passage of liquid between the rails and the pan. It is a further object to provide such a device where the covers can be removed or replaced with a rail car located above the pan. It is a further object to provide such a device with internal grating so that workers can stand or walk over the pan and cover without contacting the liquid retained in the pan. It is a further object to provide connector fittings or conduits in the side walls of the pan so that adjoining pans can be connected in a liquid communicating manner so that liquid is able to flow from one pan to the next, or to allow for connection of removal conduits to pump or direct the liquid from the pan. These and other objects not expressly set forth will become obvious after review of the accompanying disclosure. 
     SUMMARY OF THE INVENTION 
     The invention is in general a liquid containment device or system adapted for capturing and retaining any liquid falling into the device, such as from a leak, spill or run-off of another liquid container, tanker or tank. In particular, the device is best adapted for use in collecting leaks, spills or run-off from railroad tanker cars and the like, where the device is designed to fit between the parallel rails of a railroad track with a railroad car positioned above it. The invention comprises in general a generally rectilinear pan or tray having opposing side walls which align with the rails and a removable cover which directs rain water into a drain opening which corresponds to an apertured drain column rising from the bottom of the pan, such that with the cover in place rain water is directed into the drain column and passed underneath the pan rather than into the pan itself. Compressible gasket members are used to fill the gap between the side walls and the rails. Multiple pans may be connected in line through connector fittings in their end walls, or drain conduits may be connected to the fittings for removal of the liquid from the pan. Apertured grating members and absorbent mats may be placed within the pans. The pans may be used in conjunction with lateral pans positioned on the outside of the rails. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the invention positioned between two rails with the cover removed, shown as connected to another similar device, and with a grating or decking member and an absorbent mat member shown in partial view. 
     FIG. 2 is a perspective view similar to FIG. 1 but shown with the cover in place to direct rain water into the drain column, also here illustrating lateral pans and a conduit joined to the connector fitting. 
     FIG. 3 is an end view with the cover raised from the pan. 
     FIG. 4 is a partial cross-sectional view taken laterally through the drain column. 
     FIG. 5 is a partial cross-sectional view taken laterally through the pan side wall, gasket and one rail. 
     FIG. 6 is a partial cross-sectional view taken longitudinally through the pan end wall showing the mating lip. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the drawings, the invention will now be described in detail with regard for the best mode and the preferred embodiment. In a general description, the invention is a liquid containment device for capturing and retaining liquids, with the liquids to be captured are referred to herein as hazardous liquids to distinguish them from rain water. Hazardous liquids include chemicals, oils, grease, fuels, contaminated water, polluted water or any other liquid which should not be allowed to flow to the ground. The invention comprises a generally rectilinear pan or tray member  10  and a removable cover member  20 , where the pan  10  is primarily adapted to be positionable between the parallel rails  100  of a railroad track. With the cover  20  removed, any hazardous liquid falling into the pan  10  is retained for subsequent disposal. When not in use, the cover  20  is placed onto the pan  10 . The cover  20  prevents rain water from entering the pan  10 , instead directing it into a drain column  30  which conducts the water underneath the pan  10  and into the ground. 
     As shown in FIGS. 1 through 3, the invention is primarily designed for use with railroad cars, the invention being sized to fit between a pair of rails  100 . The rails  100  are comprised of a base member  101 , a vertical member  102  and a top member  103 , such that the rails  100  have a generally I-shaped configuration. The wheels of the rail cars rest on the top member  103  with the wheel flange abutting the interior side of the top member  103 . The invention is designed so that it does not interfere with or overlay the top members  103  such that movement of rail cars over the invention is not impeded, with or without the cover  20  in place. Furthermore, the invention is designed such that the cover  20  can be removed from the pan  10  even with a rail car stationed above it. While described herein with reference to use in a railway setting, it is understood that the invention can be utilized for other applications requiring liquid retention. The invention is preferably constructed of a rugged, chemical resistant, polymer material, such as polyethylene, to keep the weight of the pan  10  and cover  20  relatively light so that they can be easily lifted and handled without the need for mechanized equipment such as a forklift, although construction from metal or other materials is possible. 
     The pan member  10  comprises a generally rectangular or square bottom member  11  with a pair of opposing side walls  12  and a pair of opposing end walls  13 , all combined to define an interior liquid containment area. The bottom  11  may be relatively flat, but is preferably provided with at least one sloping surface  14  to cause the hazardous liquid to pool at a low point or area. As shown in FIG. 1, the bottom  11  comprises a pair of sloping surfaces  14  descending toward and meeting along a lowermost center line  15  which extends between the end walls  13 . Alternatively, the lowermost area could be disposed at any location on the bottom  11 . The side walls and end walls  13  are preferably no more than about six inches in height so that they do not extend above the height of the top member  103 . A rail gasket member  91  of compressible material is positioned between or affixed to the side wall  12  and the vertical member  102 . The rail gasket members  91  are longitudinally extensive members preferably composed of a closed cell foam material. The rail gaskets  91  are sealing members which insure that no hazardous liquids passes between the rails  100  and the pan  10 . As shown in FIGS. 1 and 5, the side walls  12  are each preferably provided with a longitudinal recess  16  extending over the majority of the length of the side wall  12 , such that the height of the side wall  12  is shortened in the area of the recess  16 . This allows hazardous liquid which falls onto the gasket member  91  to drain across the recess and into the pan  10 . Preferably, the gasket member  91  is provided with an inward sloping upper surface, and most preferably the gasket member  91  is composed of an exterior member  91   b  which abuts the rail  100  and an interior member  91   a  which abuts the side wall  12 . By composing the gasket member  91  from two components, insertion between the rail  100  and the side wall  12  with the pan  11  in place is made much simpler because of the reduced thickness of each member  91   a  and  91   b.  Most preferably, the recess  16  in side wall  12  is provided with an external lip  17  which presses into the body of interior member  91   a,  and interior member  91   a  is most preferably formed with an interior shoulder which rests in recess  16 . This design is best suited for preventing loss of hazardous liquids between the rails  100  and the side walls  12  of the pan  11 . Gasket members  91  of compressible material are required to accommodate the wheel flanges on the rail cars. 
     A drain column  30  extends upwardly from the bottom  11  of the pan  10 , as shown in FIGS. 1 and 4. The drain column  30  is preferably centered between the side walls  12 , but may be located at any point on the bottom  11 . The drain column  30  is preferably circular in horizontal cross-section, and comprises a flat or convex top member  31  and a sloping wall member  32  defining an interior with an open bottom  34 , such that the overall configuration of the drain column  30  is that of a truncated cone. One or more, and preferably multiple, apertures  33  are positioned in the upper portion of the wall member  32 . These apertures  33  allow rain water to pass through the open bottom  34  of drain column  33  to be conducted beneath the bottom  11  of the pan  10  when the cover  20  is in place. The apertures are most preferably slanted upward in the direction toward the interior of the drain column  30  so that any hazardous liquid which falls onto the top  31  or wall  32  of the drain column  30  when the cover  20  is removed will flow down into the bottom  11  of the pan  10  rather than through the apertures  33  and onto the ground. Placement of the apertures  33  near the top  31  of the drain column  30  allows a large volume of hazardous liquid to be retained by the pan  10  before the chance of overflow can occur. To further prevent accidental loss of hazardous liquid, absorbent mat members  93  can be placed into the pan  10 , the mats  93  being removed and replaced when saturated. Additionally, apertured grating or deck members  92  can be placed into the pan  10  to provide sufficient support such that the grating  92  or the cover  20  can be walked upon. To increase the safety factor, the bottom  11  of the pan  10  may also be provided with a non-slip or non-skid surface for better traction. 
     In a more preferred embodiment, the pans  10  are provided with one or more lateral openings  51  and connector or bulkhead fittings  52  positioned in the end walls  13 , preferably below the level of the apertures  33  in the drain column  30 . This allows multiple pans  10  to be connected in line, as shown in FIG. 1, such that excessive hazardous liquid in one pan  10  can flow through the connector fittings  52  to adjacent pans  10 , thereby greatly reducing the likelihood of overflow from a single pan  10 . For this modular system, one of the end walls  13  of the pan  10  is provided with a mating lip  19 , as shown in FIG. 6, such that hazardous liquid is precluded from passing between adjoining pans  10 . Furthermore, conduit members  94 , such as a pumping hose, can be connected to the connector fitting  52  to drain the pan  10 , as shown in FIG.  2 . When not connected to the fittings  52  of another pan  10 , the lateral opening  52  if present is plugged or sealed in suitable manner. Alternatively, connector fittings  52  can be positioned in the bottom  11  of the pan  10  where in-ground conduits or sumps are present or desired. To accommodate the fittings  52  in the bottom  11  of the pan  10 , at least one and preferably multiple circular depressions  18  are provided to define a low point. The provision of multiple depressions  18  provides alternative sites such that at least one depression  18  will be accessible between the railroad ties underlying the pan  10 . 
     The cover  20  is illustrated in FIGS. 2,  3  and  4 , and is preferably formed as a unitary member comprising a pair of opposing side edges  21  and at least one sloping surface  25 , but preferably two sloping surfaces  25  which meet at a valley or center line  26 , where the center line extends parallel to the side edges  21 . The cover  20  extends across the pan  10  and preferably fits generally flush atop the side walls  12  and end walls  13 . The side edges  21  of the cover  20  are relatively thin and abut the gasket members  91  when in use. Mechanical interlocks such as flanges, lugs or posts, not shown, may be incorporated in the cover  20  to secure the cover  20  to the side and end walls  12  and  13 , or to deck members  92  if present, to prevent undesired lateral movement of the cover  20 . The one or more sloping surfaces  25  direct rain water toward and into a drain opening  22  defined by a depending annular spout member  23 . The spout  23  is open on the bottom and corresponds in location and configuration to the location and configuration of the drain column  30  of the pan  10 , such that with the cover  20  properly positioned on the pan  10  the spout  23  mates with the wall  32  of said drain column  30  to form a sealed junction to force rain water to flow into the apertures  33 . Preferably, the interior of the spout  23  is provided with an annular sealing or gasket member  24  made of a compressible material to better preclude passage of water into the pan  10 , as seen in FIG.  4 . Rain water strikes the cover  20  and is directed by the inward sloping surfaces  25  to the drain opening  22  and into the spout  23 , where the sealed junction with the sloping wall  32  of the drain column  30  causes the water to flow through the apertures  33  and directly to the ground beneath the pan bottom  11 . It is preferred that the cover  20  be completely removable from the pan  10 , which allows the cover  20  to be removed or applied even with a rail car in place, but hinged constructions are possible so long as they do not interfere with movement of the rail car wheels over the rail top members  103 . 
     The invention may also be incorporated as part of a system which utilizes lateral pans or trays  40  with complete covers  41 , as shown in FIG.  2 . The lateral pans  40  can be provided with connector fittings  52  so that a modular construction with multiple pans  40  is possible as described above for the central pans  10 . 
     It is contemplated that equivalents and substitutions for certain elements set forth in the embodiments above may be obvious to those skilled in the art without departing from the spirit of the invention, and therefore the true scope and definition of the invention is to be as set forth in the following claims.