Abstract:
Self-raising drive-over entranceways for containment berms are disclosed. The entranceway includes a horizontal bottom panel and a collapsible sidewall that is held in a partially collapsed position forming a void between the bottom panel and sidewall. During a spill or the filling of the containment berm with a fluid, the void area between the partially collapsed sidewall and the horizontal bottom panel fills with the fluid and exerts hydrostatic pressure against the partially collapsed sidewall, forcing it to rotate upward. The higher the fluid level, the more hydrostatic pressure is applied against the sidewall, forcing it up higher until the sidewall obtains a vertical orientation. The sidewall may be restrained either by straps, braces or the like to prevent the fluid from escaping the containment area.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/831,752 filed Jun. 6, 2013, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to containment berms, and more particularly relates to self-raising drive-over entranceways for containment berms. 
     BACKGROUND INFORMATION 
     Liquid containment berms are used to prevent hazardous fluids from entering the environment from the spillage of the fluids during, for example, the loading and unloading of storage containers and transport vehicles, wash-down of equipment and vehicles, and repair/maintenance of equipment and vehicles. Conventional containment berms may be intended for permanent use, while others are designed to be portable. 
     One type of permanent containment berm is disclosed in U.S. Pat. No. 5,820,297, which is incorporated herein by reference. Such permanent berms are built from multiple elongated strips connected by corner pieces that are secured to a floor or ground by an adhesive such as caulking. 
     Examples of portable containment berms are disclosed in U.S. Pat. Nos. 5,316,175, 5,762,233, 6,092,686 and 6,880,720, which are incorporated herein by reference. Such portable berms have a floor and sidewalls made with flexible sheets of barrier material that allows the berms to be folded or rolled up for easy storage and transport. The flexible sidewalls may be held in their raised vertical positions by braces. 
     SUMMARY OF THE INVENTION 
     The present invention provides self-raising drive-over entranceways for containment berms. The entranceway includes a horizontal bottom panel and a collapsible sidewall that is held in a partially collapsed position forming a void between the bottom panel and sidewall. During a spill or the filling of the containment berm with a fluid, the void area between the partially collapsed sidewall and the horizontal bottom panel fills with the fluid and exerts hydrostatic pressure against the partially collapsed sidewall, forcing it to rotate upward. The higher the fluid level, the more hydrostatic pressure is applied against the sidewall, forcing it up higher until the sidewall obtains a vertical orientation. The sidewall may be restrained either by straps, braces or the like to prevent the fluid from escaping the containment area. The self-raising drive-over entranceways may be used in conjunction with permanent or portable containment berms. For example, the self-raising drive-over entranceways may be substituted for a wall section of a permanent containment berm to allow easy access to the containment area by vehicles such as trucks, carts, hand-trucks and the like. 
     An aspect of the present invention is to provide a containment berm comprising: at least one fluid-containing sidewall; and at least one entranceway attached to the at least one fluid-containing sidewall. The at least one entranceway comprises: a bottom panel; a collapsible sidewall movable from a partially collapsed position to a raised position upon introduction of a fluid into the containment berm, and movable from the partially collapsed position to a fully collapsed position upon traverse of a vehicle across the entranceway; and a limiter attached to the bottom panel structured and arranged to support the collapsible sidewall in its partially collapsed position. 
     Another aspect of the present invention is to provide a containment berm comprising: at least one fluid-containing sidewall; and at least one entranceway attached to the at least one fluid-containing sidewall. The at least one entranceway comprises: a bottom panel; a collapsible sidewall movable from a partially collapsed position to a raised position upon introduction of a fluid into the containment berm, and movable from the partially collapsed position to a fully collapsed position upon traverse of a vehicle across the entranceway, wherein the collapsible sidewall does not include a flotation device attached thereto and is movable from the partially collapsed position toward the raised position as a result of hydrostatic force applied by the fluid against the collapsible sidewall; and a limiter between the bottom panel and the collapsible sidewall structured and arranged to support the collapsible sidewall in its partially collapsed position. 
     A further aspect of the present invention is to provide a containment berm comprising: at least one substantially rigid modular fluid-containing sidewall; and at least one entranceway attached to the at least one fluid-containing sidewall. The at least one entranceway comprises: a bottom panel; a collapsible sidewall movable from a partially collapsed position to a raised position upon introduction of a fluid into the containment berm, and movable from the partially collapsed position to a fully collapsed position upon traverse of a vehicle across the entranceway; and a limiter between the bottom panel and the collapsible sidewall structured and arranged to support the collapsible sidewall in its partially collapsed position. 
     Another aspect of the present invention is to provide an entranceway for a containment berm comprising: a bottom panel; a collapsible sidewall movable from a partially collapsed position to a raised position upon introduction of a fluid into the containment berm, and movable from the partially collapsed position to a fully collapsed position upon traverse of a vehicle across the entranceway; and a limiter attached to the bottom panel structured and arranged to support the collapsible sidewall in its partially collapsed position. 
     These and other aspects of the present invention will be more apparent from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a containment berm having a self-raising drive-over entranceway in accordance with an embodiment of the present invention. 
         FIG. 2  is an isometric view of the containment berm of  FIG. 1 , with a fluid contained therein. 
         FIG. 3  is a partially schematic side view illustrating a self-raising drive-over entranceway with a collapsible sidewall in a partially collapsed position in accordance with an embodiment of the present invention. 
         FIG. 4  is a partially schematic side view similar to  FIG. 3  with the collapsible sidewall in a fully collapsed position. 
         FIG. 5  is a partially schematic side view similar to  FIG. 3  with the collapsible sidewall moved upward as a result of hydrostatic pressure applied by a fluid contained in the berm. 
         FIG. 6  is a partially schematic side view similar to  FIG. 3  with the sidewall in a fully raised position as a result of hydrostatic pressure applied by a fluid contained in the berm. 
         FIG. 7  is a partially schematic side view illustrating movement of a collapsible sidewall from a partially collapsed position to a raised position in which the sidewall is restrained by a strap in accordance with an embodiment of the present invention. 
         FIG. 8  is a partially schematic side view illustrating movement of a collapsible sidewall and an attached limiter from a partially collapsed position to a raised position where the sidewall is restrained by a strap. 
         FIGS. 9 and 10  are partially schematic side views illustrating movement of a collapsible sidewall from a partially collapsed position ( FIG. 9 ) in which the sidewall rests on a limiter to a raised position ( FIG. 10 ) in which the sidewall is restrained by the limiter. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  illustrate a containment berm  10  in accordance with an embodiment of the present invention. The containment berm  10  includes fluid-containing sidewalls  12  and a self-raising drive-over entranceway  20  in accordance with an embodiment of the present invention. In  FIG. 1 , the self-raising drive-over entranceway  20  is in a partially collapsed position and the containment berm  10  does not have a fluid contained therein. In  FIG. 2 , the self-raising drive-over entranceway  20  is in a raised containment position in which a fluid F is contained inside the berm  10 . As shown in  FIG. 1 , the self-raising drive-over entranceway  20  has a length L that may be selected as desired to accommodate vehicles of various sizes. In certain embodiments, the length L of the self-raising drive-over entranceway  20  may typically range from 2 to 20 feet, for example, from 3 to 10 feet. 
     The self-raising drive-over entranceway  20  includes a bottom panel  22  that may be secured to the floor or ground by any suitable means such as an adhesive. In the embodiment shown in  FIGS. 1 and 2 , the bottom panel  22  includes an optional extended portion  23 . A collapsible sidewall  24  is connected to the bottom panel  22 . For example, the bottom panel  22  and collapsible sidewall  24  may be formed from a single sheet of flexible material that can fold at the intersection of the bottom panel  22  and collapsible sidewall  24  so as to form a flexible hinge or fold line  25 . Alternatively, the bottom panel  22  and collapsible sidewall  24  may comprise separate sheets of material that are sealed together by any suitable means such as adhesive, welding, or the like. The bottom panel  22  and collapsible sidewall  24  may comprise any suitable liquid-proof flexible material, such as modified vinyl or polyurethane coated fabric or nonwoven. 
     The collapsible sidewall  24  may have vertical stiffening ribs (not shown) attached or embedded into it. The collapsible sidewall  24  may be restrained, braced or the like to prevent unwanted outward movement beyond the fully raised position. For example, as shown in  FIGS. 1 and 2 , restraining straps  40  may be provided in order to restrict the vertical movement of the sidewall  24  to approximately 90° from horizontal. Grommets  38  may be provided in the collapsible sidewall  24 . 
     The entranceway  20  may be sealed at each end to the fluid-containing sidewall  12  of a containment berm  10  by means of foldable connecting flaps  30 . The fluid-containing sidewalls  12  may be of the permanent type, e.g., each fluid-containing sidewall  12  may be substantially rigid and/or non-collapsible. In certain embodiments, such permanent fluid-containing sidewalls  12  may be of modular construction, may be secured together with corner pieces, and may be secured to a floor or ground by an adhesive. In other embodiments, the fluid-containing sidewalls  12  may be flexible and/or collapsible, for example, when the containment berm  10  is of the portable type. 
     The self-raising drive-over entranceway  20  includes a limiter  26  that holds the collapsible sidewall  24  in a partially collapsed position. As shown in  FIG. 3 , the limiter  26  prevents the collapsible sidewall  24  from completely lowering in order to allow a small void space V between the sidewall  24  and the bottom panel  22 . When the collapsible sidewall  24  is in its partially collapsed position, any liquid introduced into the containment berm is contained as a result of the fluid entering the void space V between the bottom panel  22  and the collapsible sidewall  24  and exerting hydrostatic pressure against the interior surface of the collapsible sidewall  24 . Such hydrostatic pressure forces the collapsible sidewall  24  upward to thereby contain the fluid. The limiter  26  may be made of any suitable material having sufficient resiliency or elasticity to return to its original shape and/or height after the weight of a vehicle or the like is removed. For example, the limiter  26  may be made of a compressible material, such as open cell polyurethane foam, or a three dimensional pocket or loop made from, for example, the same flexible material of the collapsible sidewall  24  or bottom panel  22 . The limiter  26  may be a continuous length across the entranceway. However, in order to facilitate the flow of fluid into the void space V between the bottom panel  22  and the collapsible sidewall  24 , the limiter may be discontinuous along its length, e.g., the limiter  26  may comprise discretely spaced segments, as shown in  FIGS. 1 and 2 . Thus, the limiter may comprise 2, 3, 4, or more segments. 
       FIGS. 3-6  sequentially illustrate how the collapsible sidewall  24  and limiter  26  of the self-raising drive-over entranceway  20  function to contain a fluid F when the fluid is introduced into a containment berm. In  FIG. 3 , the sidewall  24  rests on the limiter  26  when no fluid is present inside the containment berm. In this partially collapsed position, the limiter  26  acts as a spacer to provide the void space V between the collapsible sidewall  24  and the bottom panel  22 . The limiter  26  has a height that holds at least a portion of the collapsible sidewall in the partially collapsed position shown in  FIG. 3 . The limiter  26  may have a typical height ranging from 0.1 to 2 inches or more, for example, from 0.25 to 1.5 inches, or from 0.5 to 1 inch. The height H P  of the collapsible sidewall  24  in its partially collapsed position may be the same as the height of the limiter  26 . In embodiments where the limiter  26  has a non-planar upper surface (e.g., rounded, peaked, etc.), its height and the height H P  of the partially collapsed sidewall  24  are measured at the highest vertical point of the limiter  26  from the bottom panel  22 . 
     Although the collapsible sidewall  24  is schematically shown in  FIG. 3  as being planar, it is to be understood that when the sidewall  24  is made of a flexible sheet of material, it may be draped over the limiter  26  and may follow the contour of at least a portion of the limiter  26 . The interior surface of the collapsible sidewall  24  may thus contact some or all of the upper surface of the limiter  26 . 
       FIG. 4  schematically illustrates the collapsible sidewall  24  and limiter  26  in a fully collapsed position in which the limiter  26  and overlying collapsible sidewall  24  have a fully collapsed height H F . In the position shown in  FIG. 4 , the limiter  26  is compressed, e.g., by the weight of a vehicle traveling thereover (not shown). After the vehicle passes, the limiter  26  and collapsible sidewall  24  return to the positions shown in  FIG. 3 . 
     As shown in  FIG. 5 , when a fluid F begins to partially fill a containment berm, it enters the void space V between the bottom panel  22  and the collapsible sidewall  24 , and comes into contact with the interior surface of the collapsible sidewall  24 . The limiter  26  ensures that the fluid passes between the upper surface of the bottom panel  22  and the interior surface of the collapsible sidewall  24 . As discussed above, the limiter  26  may be provided in discrete segments along its length to facilitate the flow of the fluid F into the void space V between the bottom panel  22  and the collapsible sidewall  24 . As shown in  FIG. 5 , hydrostatic pressure of the fluid F begins to force the collapsible sidewall  24  upward. Thus, the collapsible sidewall  24  does not require the use of a flotation device to raise the sidewall  24  when fluid is introduced into the berm. Instead, the collapsible sidewall  24  is raised by the hydrostatic pressure of the fluid itself. 
     As shown in  FIG. 6 , the collapsible sidewall  24  has moved to its raised position as the fluid F continues to fill the containment berm  10 . In the raised position shown in  FIG. 6 , the collapsible sidewall  24  has a raised position height H R  sufficient to contain the fluid F. The raised position height H R  is measured from the bottom panel  22  to the upper edge of the collapsible sidewall  24 . 
     In accordance with embodiments of the present invention, the partially collapsed position height H P , fully collapsed position height H F , and raised position height H R  may be selected in order to provide both sufficient fluid containment capabilities and drive-over capabilities for the self-raising drive-over entranceway  20 . For example, the partially collapsed position height H P  may be at least 10 percent or 20 percent greater than the fully collapsed height H F . In certain embodiments, the partially collapsed position height H P  may be from 50 percent to 500 percent greater than the fully collapsed position height H F . 
     The raised position height H R  of the collapsible sidewall  24  may be selected in order to provide desired fluid containment. In certain embodiments, the raised position height H R  may range from 1.5 to 18 inches, for example, from 2 to 12 inches. The raised position height H R  may be at least twice as high as the partially collapsed position height H P , for example the ratio of H R :H P  may range from 5:1 to 40:1, or from 8:1 to 30:1, or from 10:1 to 20:1. 
     Although the containment berm  10  shown in the figures has bottom panels that do not extend across the entire width or length of the containment berm  10 , it is to be understood that a continuous bottom panel or sheet may alternatively be provided. For example, the bottom panel  22  may extend across the entire interior length and width of the sidewalls  12  in order to provide a continuous fluid-containing floor across the bottom of the containment berm  10 . In this case the containment berm may be portable, and adhesives or other sealants may not be required or desired for securing and sealing the bottom surfaces of the bottom panel  22  and sidewalls  12  to the ground. 
       FIG. 7  is a partially schematic side view showing movement of the collapsible sidewall  24  from the partially collapsed position (shown in  FIG. 3  in phantom) to its raised position similar to the position (shown in  FIG. 6 ). However,  FIG. 7  also illustrates the extended position of a restraining strap  40  that prevents the collapsible sidewall  24  from rotating past its substantially vertical position. Any suitable number of restraining straps  40  may be used, e.g., 1, 2, 3, 4, 5 or more. Each restraining strap  40  may comprise a sheet of foldable material, hinged rigid members, and the like. As more fully described below, in one embodiment, the restraining strap(s) may also act as a limiter to maintain a sufficient void space between the bottom panel  22  and the collapsible sidewall  24 . 
       FIG. 8  illustrates another embodiment of the present invention in which a limiter  56  is secured to the collapsible sidewall  24  instead of the bottom panel  22 . In the embodiment shown, the limiter  56  is provided in the form of an open pocket or loop of material formed from a strip of flexible material having its edges attached to the collapsible sidewall  24 . The space inside the limiter  56  may be open to the atmosphere, e.g., the inner space may be in the form of an air gap that is not sealed and/or pressurized. As shown in  FIG. 8 , when the collapsible sidewall  24  moves from its partially collapsed position (shown in phantom) to its raised position, the limiter  56  is secured to, and travels with, the collapsible sidewall  24 . Any suitable means for attaching the limiter  56  to the collapsible sidewall  24  and/or to the bottom panel  22  may be used in accordance with the present invention, for example, adhesives, welding, stitching, mechanical fasteners, clamps and the like. 
     In the embodiment shown in  FIG. 8 , the limiter  56  is attached to the interior surface of the collapsible sidewall  24  at a location that is spaced from the upper edge of the sidewall  24 . For example, the limiter  56  may be separated from the upper edge of the collapsible sidewall  24  a distance that is at least 5 or 10 percent of the raised height of the sidewall  24 . As shown in phantom in  FIG. 8 , such a spacing distance creates an overhang of the edge of the collapsible sidewall  24  over the limiter  56 . The overhang helps ensure that any fluid that fills the containment berm will pass under the overhang of the collapsible sidewall  24  and into the void space V between the bottom panel  22  and sidewall  24  to thereby exert hydrostatic pressure against the interior surface of the sidewall  24  to force it to raise. The embodiment shown in  FIG. 8  does not require the use of a flotation device to raise the sidewall  24  upon introduction of a fluid into the berm, but rather relies on the hydrostatic pressure of the fluid. 
       FIGS. 9 and 10  illustrate the use of a limiter  126  in accordance with another embodiment of the present invention. As shown in  FIG. 9 , when the collapsible sidewall  24  is initially in its partially collapsed position, the limiter  126  maintains the void space V and the collapsible sidewall  24  is held at its the partially collapsed position height H P  described above. In the embodiment shown, the limiter  126  has a bottom leg  127  attached to the bottom panel  22  and top leg  128  attached to the collapsible sidewall  24  that may be folded together as shown in  FIG. 9 . Although the bottom and top legs  127  and  128  form a V-shape in the embodiment shown in  FIG. 9 , it is to be understood that the bottom and top legs may alternatively lie flat against each other. As shown in  FIG. 10 , when the collapsible sidewall  24  moves from its partially collapsed position H P  to its raised position H R , the limiter  126  also serves as a restraining strap that prevents over rotation of the collapsible sidewall  24  past its substantially vertical position. Each or both legs  127  and  128  may have a thickness of from 0.02 to 1 inch, or from 0.1 to 0.8 inch, or from 0.15 to 0.5 inch, to achieve the desired partially collapsed height H P  of the collapsible sidewall  24 . Alternatively, pockets or gaps may be provided between the folded bottom and top legs  127  and  128 , between the bottom leg  127  and bottom panel  22  and/or between the top leg  128  and the collapsible sidewall  24  in order to achieve the desired partially collapsed height H P  of the sidewall  24 . 
     Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.