Abstract:
Portable collapsible fluid containment devices are disclosed comprising sidewall support braces that rotate from a collapsed generally horizontal position to a raised generally vertical position and lock into place. The sidewall braces may be attached to at least one sidewall of the containment device, and when raised support the sidewall in a fluid containment configuration. The sidewall braces comprise a base support leg, a sidewall support arm rotatably mounted on the support leg, and a locking tab for holding the sidewall support arm in the generally vertical position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/097,903 filed Dec. 30, 2014, which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to collapsible fluid containment devices, and more particularly relates to locking sidewall support braces for use in fluid containment devices. 
       BACKGROUND INFORMATION 
       [0003]    Portable collapsible liquid containment devices are used to prevent hazardous fluids from entering the environment from, for example, spillage of the fluids during loading and unloading of transport vehicles, wash-down of equipment and vehicles, and repair/maintenance of equipment and vehicles. Typically one or more sides of the containment device can be lowered and laid flat so that the equipment or vehicle can easily enter the containment area. Once the equipment or vehicle is inside, the sidewall(s) are then raised to prevent fluids from escaping. Any spilled fluid or wash-down fluid is retained within the container and can be pumped out for proper disposal. After the container is emptied, the sidewall(s) can be lowered again to remove the equipment or vehicle. The container can then be folded or rolled-up for storage and transport. 
         [0004]    Such containment devices are typically made with a flexible barrier material, such as a rubberized fabric, reinforced polyvinyl chloride (PVC), reinforced thermoplastic polyurethane (TPU) and/or a heavy gauge polymer film. During use, the containment device is unfolded/unrolled and the sides extended to a generally vertical position to achieve its fluid retaining capability. To maintain the sidewalls in this generally vertical position, collapsible sidewall braces may be employed, as exemplified in U.S. Pat. Nos. 5,316,175; 5,762,233; 6,092,686; 6,880,720; and 8,562,251 and published US Patent Application Nos. 2013/0240538 and 2014/0246441, which are incorporated herein by reference. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides portable collapsible fluid containment devices comprising sidewall support braces that rotate from a collapsed generally horizontal position to a raised generally vertical position and lock into place. The sidewall braces may be attached to at least one sidewall of the containment device, and when raised support the sidewall in a fluid containment configuration. The sidewall braces comprise a base support leg, a sidewall support arm rotatably mounted on the support leg, and a locking tab for holding the sidewall support arm in the generally vertical position. 
         [0006]    An aspect of the present invention is to provide a collapsible fluid containment device comprising a collapsible sidewall, and a plurality of sidewall braces attached to the collapsible sidewall, wherein each sidewall brace comprises a base support leg, and a sidewall support arm pivotably mounted on the base support leg around an axis of rotation, wherein the sidewall support arm comprises a locking tab including a radial projection extending from the locking tab radially from the axis of rotation engageable with an upper surface of the base support leg. 
         [0007]    Another aspect of the present invention is to provide a sidewall brace for use in a collapsible fluid containment device, the sidewall brace comprising a base support leg, and a sidewall support arm pivotally mounted on the base support leg and rotatable around an axis of rotation from a collapsed position in which the sidewall support arm is substantially parallel with the base support leg to a raised position in which the sidewall support arm is substantially perpendicular to the base support leg, wherein the sidewall support arm comprises a locking tab engageable with a contact surface of the base support leg to thereby resist movement of the sidewall support arm from its raised position to its collapsed position. 
         [0008]    These and other aspects of the present invention will be more apparent from the following description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an isometric view of a fluid containment device including multiple locking sidewall braces in accordance with an embodiment of the present invention. 
           [0010]      FIG. 2  is an isometric view of a locking sidewall brace in a collapsed position in accordance with an embodiment of the present invention. 
           [0011]      FIG. 3  is an isometric view of a locking sidewall brace in a raised position in accordance with an embodiment of the present invention. 
           [0012]      FIG. 4  is a side view of a locking sidewall brace in a collapsed position in accordance with an embodiment of the present invention. 
           [0013]      FIG. 5  is a side view of a locking sidewall brace in a raised position in accordance with an embodiment of the present invention. 
           [0014]      FIG. 6  is an end view of a collapsed locking sidewall brace in accordance with an embodiment of the present invention. 
           [0015]      FIG. 7  is a sectional view of the locking sidewall brace taken through section  7 - 7  of  FIG. 6 . 
           [0016]      FIG. 8  is an end view of a raised locking sidewall brace in accordance with an embodiment of the present invention. 
           [0017]      FIG. 9  is a sectional view of the locking sidewall brace taken through section  9 - 9  of  FIG. 8 . 
           [0018]      FIG. 10  is an end view of a collapsed locking sidewall brace in accordance with another embodiment of the present invention. 
           [0019]      FIG. 11  is a sectional view of the locking sidewall brace taken through section  11 - 11  of  FIG. 10 . 
           [0020]      FIG. 12  is an end view of the locking sidewall brace of  FIGS. 10 and 11  with its sidewall support arm rotated to an intermediate position. 
           [0021]      FIG. 13  is a sectional view of the locking sidewall brace taken through section  13 - 13  of  FIG. 12 . 
           [0022]      FIG. 14  is an end view of the locking sidewall brace of  FIGS. 10-13  in a fully raised position. 
           [0023]      FIG. 15  is a sectional view of the locking sidewall brace taken through section  15 - 15  of  FIG. 14 . 
           [0024]      FIG. 16  is an end view of a locking sidewall brace in an intermediate position between a collapsed position and a fully raised position in accordance with an embodiment of the present invention. 
           [0025]      FIG. 17  is a sectional view of the locking sidewall brace taken through section  17 - 17  of  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION 
       [0026]      FIG. 1  illustrates a fluid containment device  5  in accordance with an embodiment of the present invention. The containment device  5  includes a bottom panel  6  and multiple collapsible sidewalls  7 . The bottom panel  6  and sidewalls  7  may be made of any suitable type of fluid-impermeable material, such as rubberized fabric, reinforced polyvinyl chloride (PVC), reinforced thermoplastic polyurethane (TPU) and/or a heavy gauge polymer film, and the like. Each sidewall  7  includes multiple bracket-receiving pockets  8 . Each pocket  8  receives a sidewall support arm of a sidewall brace  10 , as more fully described below. Similar pockets (not shown) may be provided under the bottom panel  6  to receive base support legs of the sidewall braces  10 . 
         [0027]      FIGS. 2-9  illustrate a locking sidewall brace  10  in accordance with an embodiment of the present invention. The locking sidewall brace  10  includes a base support leg  12  having a first end  14  and a second end  16 . The base support leg  12  includes a contact surface  13 . A raised portion  15  of the base support leg  12  is provided near the first end  14  of the base support leg  12 . The base support leg  12  includes support ribs  17  terminating in stop members  18 . A hole  19  is provided through the base support leg for receiving a stake (not shown) or other mechanical device for securing the locking sidewall brace  10  to the ground during use. 
         [0028]    As shown in  FIGS. 2 and 4 , the first end  14  of the base support leg  12  and the support ribs  17  form a low-profile ramp having a ramp angle A measured from a horizontal plane. The ramp angle A is selected to facilitate the travel of wheeled vehicles over the sidewall brace  10 , e.g., when traversing the sidewall  7  upon entering or exiting the containment area of the containment device  5 . The ramp angle A may typically range from 5° to 45°, for example, from 10° to 30°, or from 15° to 25°. This section is tapered downward and away from the containment area. This allows the wheels of vehicles and equipment entering the containment area when the sidewall is down roll easily over the brace. 
         [0029]    The locking sidewall brace  10  also includes a rotatable sidewall support arm  20  having a first end  22  and a second end  24 . A cut-out portion  23  is provided in the sidewall support arm  20  near the first end  22 . As shown most clearly in the sectional views of  FIGS. 7 and 9 , the rotatable sidewall support arm  20  includes an eccentric locking tab  25  near the first end  22 . The locking tab  25  includes a notch  26  and a radial projection  27 . As more fully described below, when the sidewall support arm  20  is rotated from the substantially horizontal collapsed position shown in  FIG. 7  to the substantially vertical raised position shown in  FIG. 9 , the radial projection  27  of the locking tab  25  presses against and moves across the contact surface  13  of the base support leg  12  when the sidewall support arm  20  reaches a pre-determined rotational position. Once the sidewall support arm  20  is rotated to its fully raised position, the locking tab  25  acts to resist rotation of the sidewall support arm  20  back to its collapsed position. The notch  26  in the locking tab  25  provides resiliency and spring action for the radial projection  27  as it moves over the contact surface  13 . A pivot hole  29  is provided through the sidewall support arm  20  for receiving a pivot pin  30  around which the sidewall support arm  20  rotates in relation to the base support leg  12 . As shown in  FIGS. 5 and 9 , the stop members  18  of the base support leg  12  contact the first end  22  of the sidewall support arm  20  when it is in the raised position, thereby providing a mechanical stop that prevents the sidewall support arm  20  from rotating beyond the desired extended position. 
         [0030]      FIGS. 10-15  illustrate a locking sidewall brace  110  in accordance with another embodiment of the present invention. Similar element numbers are used in  FIGS. 10-15  for common features that are present in the embodiment of  FIGS. 2-9 .  FIGS. 10 and 11  illustrate the locking sidewall brace  110  with its rotatable sidewall support arm  120  in a collapsed position.  FIGS. 12 and 13  illustrate the locking sidewall brace  110  with the rotatable sidewall support arm  120  in an intermediate position.  FIGS. 14 and 15  illustrate the locking sidewall brace  110  with the rotatable sidewall support arm  120  in a fully raised position. The rotatable support arm  120  includes an eccentric locking tab  125  having a curved contact surface  126  and a radial projection  127 . The curved contact surface  126  may be circular and is circumferentially spaced from the radial projection  127 , as measured around the axis of rotation of the sidewall support arm  120 . The radial projection  127  contacts the contact surface  13  of the support leg  12  when the support arm  120  is rotated from the raised position to the collapsed position to thereby help hold the support arm  120  in its raised position. 
         [0031]      FIGS. 16 and 17  illustrate a locking sidewall brace  210  in accordance with a further embodiment of the present invention. In this embodiment, similar element numbers are used to describe the same features found in the previous embodiments. The locking sidewall brace  210  includes a rotatable sidewall support arm  220 , which is shown in an intermediate position in  FIGS. 16 and 17  between a fully collapsed position and a fully raised position. The rotatable sidewall support arm  220  includes an eccentric locking tab  225  with a curved contact surface  226  and a radial projection  227 . The curved contact surface  226  and radial projection  227  form a cammed configuration in which the radial projection provides a cam surface. The cam surface of the radial projection  227  contacts the contact surface  13  of the support leg  12  when the support arm  220  is rotated from the raised position to the collapsed position to thereby help hold the support arm  220  in its raised position. 
         [0032]    Due to the eccentric shapes of the locking tabs  25 ,  125  and  225 , the sidewall support arms  20 ,  120  and  220  of the sidewall braces  10 ,  110  and  210  offer minimal resistance to rotation from their initial collapsed horizontal positions until the support arms have rotated upward, e.g., to approximately 75° from horizontal. At this point, resistance or torque increases, e.g., for approximately 5° to 15° of rotation, then returns to minimal resistance until the support arms  20 ,  120 ,  220  contact the mechanical stops  18 . In certain embodiments, the frictional engagement between the locking tabs  25 ,  125  and  225  and the contact surface  13  of the base support leg  12  occurs at a resistance angle of from 60° to 90° from a horizontal plane, for example, from 70° to 80°. In certain embodiments, the locking tabs may have single or multiple radial projections. The radial projections may have a curvilinear profile as shown in the figures, or an angular profile such as a ratchet tooth. Projection(s) may also be included on the base support leg  12  to contact the radial projection(s) of the sidewall support arms  20 ,  120  and  220 . 
         [0033]    In order for the sidewall support arms  20 ,  120  and  220  to rotate beyond about 75°, either the locking tabs  25 ,  125  and  225 , or the contacted surface  13  of the base support leg  12 , or both, may flex to provide clearance for the sidewall support arms  20 ,  120  and  220  to continue rotation. Such flexing provides the rotational resistance for the locking mechanism. The rotation resistance may be lower than torque exerted by hydrostatic pressure of a contained liquid when it presses against the sidewall  7 . The rotation resistance may be controlled by the spacing of the sidewall braces  10  from each other, the vertical design height of the containment device, and the specific gravity of the liquid being contained. For example, a minimal level may be about 4 pound-inches in order to resist wind gusts and other forces from unintentionally lowering the sidewall when the containment device is empty of liquid. 
         [0034]    The mechanical stops  18  may be located to prevent the support arms  20 ,  120  and  220  from rotating past approximately 90° from horizontal. For example, the mechanical stops  18  may stop rotation of the sidewall support arms  20 ,  120  and  220  at a stop angle of from 90° to 120°, or from 100° to 110°, or at about 105°, from horizontal. The support arms  20 ,  120  and  220  are thus trapped or locked in an upright position between the mechanical stops  18  and the high rotation resistance position of the support arms  20 ,  120  and  220  when their locking tabs  25 ,  125  and  225  engage the contact surface  13  of the base support leg  12 . For example, such an upright range may be from 60° to 120° from horizontal, typically between 70° and 110°, or between 75° and 105°, all of which are inclusive of 90°. To lower the support arms  20 ,  120  and  220 , a sufficient amount of torque is applied against the support arms  20 ,  120  and  220  to overcome the high rotation resistance of the locking tabs  25 ,  125  and  225 . 
         [0035]    In the various embodiments illustrated in  FIGS. 2-17 , the base support leg  12  and the sidewall support arms  20 ,  120  and  220  may be made of any suitable material, e.g., injection molded from plastic. For example, the legs and arms may be made from nylon or filled nylon for strength. Alternately any moldable plastic can be used or they can be cast or machined from metal such as aluminum. The support legs and support arms can be made of separate material types. The pivot pin  30  is preferably made from a non-oxidizing material such as stainless steel. For example, the pivot pin  30  can be a stainless steel shoulder bolt retained by a stainless steel lock nut. Alternately, the pivot pin  30  can be made of plastic and can be molded as an integral section of the either the horizontal support leg or the support arm. 
         [0036]    Each horizontal support leg  12  may be attached to the underside of the containment device floor  6 , and each support arm  20 ,  120 ,  220  may be attached to the sidewall  7  of the containment device  5 . For example, the support arms  20 ,  120  and  220  may be inserted in the pockets  8  attached to the sidewalls  7 . In addition, the base support legs  12  may be inserted in pockets (not shown) under the bottom panel  6 . In the embodiment shown, the pockets  8  are attached to the exterior side of the sidewall  7 . Alternatively, pockets may be provided on the interior of the sidewall  7 , in which case the sidewall braces  10  may be located inside the sidewall  7  with their sidewall support arms inside the pockets and their base support legs inserted into pockets located above the bottom panel  6 . As described above, each sidewall support arm  20 ,  120  and  220  can be rotated from a horizontal position to an approximate vertical position as to raise the containment sidewall. To lower the sidewall the support arm is returned to the horizontal position. The direction of rotation of the support arms  20 ,  120  and  220  may be such that it pivots downward toward the interior of the containment device  5  when the sidewall  7  is lowered. 
         [0037]    An advantage of having little or no initial rotational resistance of the support arms  20 ,  120  and  220  when they are in their collapsed positions is that the hydrostatic pressure of a liquid entering the containment device  5  when the sidewall(s)  7  are lowered is sufficient to self-rise the sidewall(s)  7  to a position above the liquid height. As the height of the fluid level rises in the containment device  5 , so does the sidewall height. When the sidewall(s)  7  reach a height corresponding to about 75° of rotation, the hydrostatic pressure of the liquid has increased enough to force the support arms  20 ,  120  and  220  through the high rotation resistant section and back against the mechanical stop  18  so that the sidewall  7  is in its fully raised and locked position. 
         [0038]    For example, in a containment device having a designed liquid retaining height of  12  inches and sidewall braces  10  spaced every 2 feet, the liquid can easy rotate the sidewall braces  10  and sidewall  7  to a height of about 11.6 inches (75° of rotation). When a liquid having a specific gravity of approximately 0.9 reaches a height of 11 inches, it exerts torque (the hydrostatic pressure) against the sidewall  7  of approximately 68 pound-inch along a 2 foot length of sidewall  7 . If the greatest rotational resistance of the sidewall braces  10  is less than approximately 68 lb. in, the hydrostatic pressure will force the sidewall braces  10  and sidewall  7  they are attached to past the high rotation resistant section and toward the mechanical stop  18 . 
         [0039]    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.