Abstract:
An apparatus for selectively providing access to a storage container having a door spaced above a floor of the container to provide access to an interior thereof comprises a shaft securable to said storage container at a position below said door and rotatable relative thereto and at least one lever arm extending from said shaft. The apparatus further includes at least one ramp extending between first and second ends, wherein said first end is supported on a surface proximate to said container. The at least one ramp is pivotally supported by distal ends of said at least one lever arms so as to be movable from a first position wherein said second end of said at least one ramp is positioned in front of said container to a second position wherein said second end of said at least one ramp is supported on said container as said shaft is rotated.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates generally to ramps used to load and unload shipping and storage containers, and in particular to a ramp which may be attached to a container and pivoted into position. 
     2. Description of Related Art 
     The movement and storage of goods throughout the world has been standardized with the use of standard intermodal containers, also known as shipping or storage containers. These containers are built to have standard dimensions, such that they can be transported using a variety of modes of transport, including ships, trains and trucks. The dimensions of the containers are specified in the ISO 668 standard, set by the International Organization of Standards. For example, a container may be loaded in a foreign country, transported via truck from the manufacturer to a seaport, loaded onto a ship then transported via ship to another seaport, unloaded from the ship and loaded onto a train, transported via train to a storage facility, then finally transported via truck to its final destination, where the goods are unloaded. 
     A container may be loaded and unloaded over an extended period of time, depending on the schedule of the shipper or receiver. At times the containers may be located in semi-permanent locations, such as in a storage facility or outside of a home or business during renovations or construction. The container may be used, for example, to store personal belongings, or it may be used to store construction materials, which must be accessed regularly, but securely locked when not in use. When a container is used for a longer period of time, it may be loaded and unloaded several times while remaining in place. Typically, a forklift or hand truck is used to move the contents in and out of the container. 
     When a container is loaded or unloaded, it is often removed from the transport vehicle and placed on a dock, placement pad or directly onto the ground. The base of the container may be supported by blocks to elevate and level the container. Regardless of whether blocks are used, the inside floor of the container is at a level above that of the surface on which it is placed; typically, the floor is about 5-7 inches higher. 
     To bridge the height difference, typically a sheet of plywood or a metal plate is used as a ramp between the inside floor of the container and the outside placement surface. This type of ramp can be a safety hazard, as it is not secured to the container and could slip from the edge of the container, possibly causing injury to a user, or causing damage to product being moved over the ramp. For many containers, such ramps will interfere with the proper closing of the door and will therefore need to be removed prior to closing such doors. It will be appreciated that ramps may be heavy and difficult to lift onto or lower from the edge of the container by hand, depending upon the material used. 
     U.S. Pat. No. 7,310,843 B1 (Mitchell) describes a ramp which may be secured to a standard shipping container, but it is not permanently secured and it does not include a lifting mechanism to raise it into place. Other ramps include lifting mechanisms, but are not designed to be permanently attached to a container. Examples of ramps with lifting mechanisms are U.S. Pat. No. 4,075,729 (Conner) and U.S. Pat. No. 4,209,869 (Trine et al.). 
     SUMMARY OF THE INVENTION 
     According to a first embodiment of the present invention there is disclosed an apparatus for selectively providing access to a storage container having a door spaced above a floor of the container to provide access to an interior thereof, the apparatus comprising a shaft securable to said storage container at a position below said door and rotatable relative thereto and at least one lever arm extending from said shaft. The apparatus further includes at least one ramp extending between first and second ends, wherein said first end is supported on a surface proximate to said container. The at least one ramp is pivotally supported by distal ends of said at least one lever arms so as to be movable from a first position wherein said second end of said at least one ramp is positioned in front of said container to a second position wherein said second end of said at least one ramp is supported on said container as said shaft is rotated. 
     The shaft may be supported by a bracket connectable to said storage container below said door. The bracket may include a sleeve sized to receive and rotatably support said shaft therein. Each of said brackets may be securable within apertures through said storage container. The bracket may include a positioning plate sized and shaped to correspond to said aperture through said storage container. The bracket may include an outer clamping body and an inner clamping body surrounding said positioning plate wherein said inner body is drawable towards said outer clamping body. 
     The apparatus may further comprise a handle rigidly connected to said shaft. The handle may comprise a bar extending substantially parallel to and spaced apart from said shaft. The bar may extend between an inner two of said at least one lever arms. 
     The at least one ramp may comprise two ramps each extending between inner and outer edges. The inner two of said at least one lever arms may support said inner edges of said two ramps. The apparatus may further comprise two outer lever arms supporting said outer edges of said ramps. 
     According to a further embodiment of the present invention there is disclosed a kit for selectively providing access to a storage container having a door spaced above a floor of the container to provide access to an interior thereof, the kit comprising a shaft securable to said storage container at a position below said door and rotatable relative thereto and at least one lever arm extending from said shaft. The kit further includes at least one ramp extending between first and second ends, wherein said first end is operable to be supported on a surface proximate to said container. The at least one ramp is adapted to be pivotally supported by distal ends of said at least one lever arms so as to be movable from a first position wherein said second end of said at least one ramp is positioned in front of said container to a second position wherein said second end of said at least one ramp is supported on said container as said shaft is rotated. 
     The kit may further comprise a bracket having a sleeve sized to rotatably support said shaft therein, said bracket being securable to the storage container below said door. The bracket may include a positioning plate sized and shaped to correspond to said aperture through said storage container and an outer clamping body and an inner clamping body surrounding said positioning plate wherein said inner body is drawable towards said outer clamping body. 
     The kit may further comprise a handle extending substantially parallel to and spaced apart from said shaft rigidly supported between an inner two of said at least one lever arms. The kit may further comprise a lock adapted to be engage against said handle and a bottom portion of said storage container with said shaft therebetween and on an opposite side thereof to prevent rotation of said shaft. The kit may further comprise an elongate pry bar sized to pass between said handle and said shaft so as to be operable to rotate said shaft when lifted by a user. 
     According to a further embodiment of the present invention there is disclosed a method for selectively providing access to a storage container having a door spaced above a floor of the container to provide access to an interior thereof, the apparatus comprising rotatably securing a shaft to said storage container at a position below said door and pivotally supporting a portion of at least one ramp extending between first and second ends to lever arms extending radially from said shaft. The method further comprises rotating said shaft so as to move said at least one ramp from a first position wherein said second end of said at least one ramp is positioned in front of said container to a second position wherein said second end of said at least one ramp is supported on said container as said shaft is rotated. 
     The method may further comprise inserting a pry bar between said shaft and a handle parallel to and spaced apart from said shaft and lifting said pry bar so as to rotate said handle and said shaft. 
     Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view, 
         FIG. 1  is a top plan partially exploded view of a ramp assembly installed on a container in the first or lowered position according to a first embodiment of the present invention. 
         FIG. 2  is a cross-sectional view of the ramp of  FIG. 1  taken along the line  2 - 2 , in the first or lowered position with a pry bar inserted into the ramp for lifting. 
         FIG. 3  is a cross-sectional view of the ramp of  FIG. 1  taken along the line  2 - 2 , in the second or raised position with a pry bar inserted into the ramp for lifting. 
         FIG. 4  is an enlarged detail cross-sectional view of the ramp of  FIG. 1  taken along the line  2 - 2 , in the second or raised position with a lock and support base installed. 
         FIG. 5  is a perspective view of a standard shipping container. 
         FIG. 6  is a perspective view of an end clamp for use with the ramp of  FIG. 1  in the first rotated installation position. 
         FIG. 7  is a perspective view of the end clamp of  FIG. 6  in the second installed position. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a ramp assembly for a standard shipping container according to a first embodiment of the invention is shown generally at  10 . A standard intermodal or shipping container  8 , having dimensions as specified by the ISO 668 standard, is shown in  FIG. 5 . ISO 668 defines a single standard external width of 8 feet (2.44 meters), whereas it defines multiple standard lengths and heights. For the present embodiment of the invention, only the width dimension of the container is relevant. Additionally, all shipping containers  8  have standard corner castings  6  such that they may be engaged with by handling equipment and standard corner locks during transport. 
     The ramp assembly  10  comprises a shaft  12 , two end brackets  70 , two incline sheets  40 , a pry bar  60 , an optional lock  120 , and an optional base support  140 . As will be described in more detail below, the end brackets  70  are attached to the corner fittings  6  of a container  8 . The shaft  12  is rotatably supported by the end brackets  70  and secured in place with collars  110 . The incline sheets  40  are attached to the shaft  12 , as will be more fully described below. The ramp assembly  10  is raised with a pry bar  60 . When in the raised position, the ramp may be secured in place with the lock  120 . Optionally, a base support  140  may be located under a midpoint of the shaft  12  to provide additional support thereto. 
     As shown in  FIG. 1 , the shaft  12  comprises an elongate cylindrical shaft extending along an axis  200  between first and second ends,  16  and  18 , respectively, two incline support brackets  20 , and a central pivot portion  22  therebetween. The shaft  12  may have a length corresponding to the width of the container  8 , such as, by way of non-limiting example, approximately 8 feet (2.44 meters). The diameter of the shaft  12  may be such as, by way of non-limiting example, in the range of ½ to 2½ inches (13 to 64 mm) and may selected to be hollow or solid. The central pivot portion  22  is located at the midpoint of the shaft  12 , and includes two lever arms or brackets  24  extending perpendicular therefrom with a cylindrical incline handle or pivot shaft  26  extending along an incline pivot axis  202  at the distal end therebetween. It will also be appreciated that the pivot shaft  26  may be located along the shaft  12  at any position other than between the ramps so as to permit a user to raise and lower the ramps using a pry bar at a side of the ramps, by way of non-limiting example as will be more fully described below. The diameter of the incline pivot shaft  26  may be such as, by way of non-limiting example, in the range of ½ to 2½ inches (13 to 64 mm) and may selected to be hollow or solid. Proximate to the distal end of each bracket  24 , a pivot pin  30  extends transversely outward along the incline pivot axis  202  and is sized to fit within a receiving bore (not shown) on an underside bracket  44  of each incline sheet  40 . The parallel incline support brackets  20  extend perpendicular from the shaft  12 , and are spaced apart from the central pivot portion  22  to fit the width of an incline sheet  40 . The size and length of each incline support bracket  20  essentially matches the size and length of each bracket  24 , with a transverse bore therethrough proximate to the distal end, along the pivot axis  202 , such that a bolt  32  may be passed therethrough to be received within a receiving bore (not shown) on an underside bracket  44  of each incline sheet  40 . The bolt  32  may be secured by a nut (not shown), as is commonly known. The length of the brackets  20  and  24  are sized relative to the diameter of each shaft  12  and  26 , such that the top lip  42  of each incline sheet  40  engages with the floor  4  of the container  8  when in the second or raised position, as best seen in  FIG. 4 . The length of the incline pivot shaft  26 , and therefore the distance between the brackets  24 , may be such as, by way of non-limiting example, up to 8 inches (203 mm) forming a pivot gap  28  to receive a pry bar  60  therein as will be more fully described below. 
     Turning now to  FIGS. 2-4 , each incline sheet  40  bridges the distance between the container floor  4  and the placement pad or ground  2 , extending between first and second ends  46  and  48 , respectively. The width of each incline sheet  40  may be such as, by way of non-limiting example, up to 42 inches (1066 mm) and spaced apart by the central pivot portion  22  of the ramp assembly  10  to accept the wheels of a forklift or a hand truck, by non-limiting example, thereon. The length of each incline sheet  40  may be sized such that the incline angle  50  in the raised position, as shown on  FIG. 3 , does not exceed 10% (5.7 degrees), or as recommended by the forklift manufacturer, as is commonly known. A lip  42 , is formed on each incline sheet  40  proximate to the first end  46 , which engages upon the floor  4  of the container  8  when in the raised position, as shown in  FIGS. 3 and 4 . Two perpendicular underside brackets  44  extend from a bottom of each side of each incline sheet  40 , proximate to the first end  46  and distal to the lip  42 . Each underside bracket  44  includes a transverse receiving bore therethrough (not shown), to be engaged upon by a pivot pin  30  or bolt  32 , as seen in  FIG. 1 , such that the incline sheet  40  may pivot along the pivot axis  202  thereon. The length of each underside bracket  44  and the location of each receiving bore is sized such that when an incline sheet  40  is engaged with a pivot pin  30  and a bolt  32  onto the brackets  20  and  24 , the edge of the lip  42  at the first end  46  of the incline sheet  40  rests on the shaft  12  in the lowered position, as illustrated in  FIGS. 1 and 2 . 
     Turning now to  FIGS. 6 and 7 , an end bracket  70  is illustrated in two positions. At the first position, shown in  FIG. 6 , the end bracket  70  is rotated to a position operable to install the end bracket  70  within a standard corner casting  6  of a container  8 .  FIG. 7  illustrates the final installed position of an end bracket  70  within the corner casting  6 . Each end bracket  70  comprises an annular sleeve  72 , a positioning body  74 , an outside clamp  76 , an inside clamp  78 , a retaining lip  80 , and two bolts  82 . As is commonly known, all corner castings  6  have standard dimensions, and include a standard corner casting opening  7  on the bottom front face. The corner casting opening  7  is an oblong shape and has an opening width, or minor axis, commonly of 2 inches (51 mm) and an opening height, or major axis, commonly of 3⅛ inches (79 mm), with a rounded top and bottom. The positioning body  74 , having front and back surfaces  96  and  98 , respectively, is also oblong and is sized and shaped to correspond to the corner casting opening  7  so as to non-rotationally fit within the corner casting opening  7  when in the final installed position, as illustrated in  FIG. 7 . For reference, an oblong shape has a major axis along the long diameter and a minor axis along the narrow diameter, which meet in the centre of the oblong. 
     The outside clamp  76  is formed in a rectangular block, extending from front  84  to back  86 , and from left side  88  to right side  90 , and from top  92  to bottom  94 . The back  86  is attached to the front surface  96  of the positioning body  74 , such that it is centred over the minor axis of the positioning body  74 . The width of the outside clamp  76  from left side  88  to right side  90  is larger than the minor axis of the opening  7  to extend to either side thereof in the secured position shown in  FIG. 7 . Two parallel bore holes passing from front  84  to back  86  of the outside clamp  76  and continuing through the positioning body  74  from front surface  96  to back surface  98  are spaced apart over the centre of the minor axis such that the distance therebetween is sized position each bore to pass through the positioning body  74  and are sized to receive the bolts  82  therethrough. The height of the outside clamp  76  from top  92  to bottom  94  is selected to provide stability and strength to the brackets such as, by way of non-limiting example, between ¼ and 2 inch (6 to 51 mm) although it will be appreciated that other dimensions for the outside clamp  76  may be useful, as well. 
     The inside clamp  78  has a similar width and height to the outside clamp  76 , with two threaded bore holes  83  spaced apart to receive the two bolts  82  passing through the outside clamp  76  and the positioning body  74 . The depth of the inside clamp  78  may be similar to the outside clamp. The bolts  82  are sized to be threadably received within the threaded bore holes  83  and are of a length sufficient to pass through the outside clamp  76 , the positioning body  74  and the inside clamp  78  such that the front of the inside clamp  78  spaced apart from the back surface  98  of the positioning body  74  by a distance sufficient to permit insertion of the inside clamp  78  through the opening when they are fully extended. 
     A retaining lip  80  having a similar width to the outside clamp  76  and having front and back surfaces  100  and  102 , respectively, is also attached to the front surface  96  of the positioning body  74 , centred over the minor axis in a similar manner. The thickness of the retaining lip  80  between the front and back surfaces  100  and  102  is selected to provide sufficient strength thereto as is commonly known. An annular sleeve  72  is sized to receive the shaft  12  therethrough, allowing a slip fit so that the shaft  12  may freely rotate therein. The annular sleeve is attached to the front surface  100  of the retaining lip  80 , centred over the minor axis of the positioning body  74 , and positioned such that the central axis of the annular sleeve  72  is parallel to the minor axis of the positioning body  74  and aligns with the main shaft axis  200 , parallel to the floor  4  of the container  8  when in the installed position as shown in  FIG. 7 . 
     Referring to  FIG. 6 , when in the first position, the end bracket  70  is rotated 90 degrees relative to the corner casting opening  7 , and the positioning body  74  cannot pass through the opening  7  as the height or major axis of the positioning body  74  is greater than the width or minor axis of the corner casting opening  7 . The width of the inside clamp  78  is less than the height or major axis of the opening  7 , and therefore can easily be passed therethrough. The bolts  82  are at their maximum extended position as the outside clamp  76  is passed through the corner casting opening  7 . Although the end bracket  70  is shown with the annular sleeve  72  rotated to the left of the corner casting opening  7 , it may be appreciated that it could be installed with the annular sleeve  72  rotated to the right, as well. 
     With the inside clamp  78  within the corner casting  6 , the end bracket  70  is rotated 90 degrees in the direction indicated at  204  such that the major and minor axes of the positioning body  74  align with the major and minor axes of the casting opening  7 , respectively, as shown in  FIG. 7 . The positioning body  74  is positioned within the casting opening  7 , and is restricted from passing therethrough as the width of the outside clamp  76  and retaining lip  80  are greater than the minor axis of the casting opening  7 . The bolts  82  are engaged upon by a wrench or torquing tool, as is commonly known, to reduce the distance between the outside clamp  76  and the inside clamp  78 , such that the inside clamp engages upon the inside of the corner casting  6 . 
     To assemble the ramp assembly  10 , the end brackets  70  are attached to the corner castings, as described above, on the opening end of the container  8 . A retaining collar  110 , is installed on each end of the shaft  12 . Each retaining collar  110  is a formed as an annular ring sized to fit the shaft  12  therethrough, with a set screw fitting, as is commonly known. Each end of the shaft  12  is passed through an annular sleeve  72  of an end bracket  70 . When the shaft  12  has been positioned such that it is centred between the two end brackets  70 , the collars  110  are positioned proximate to each end bracket  70  on the shaft  12 , as shown in  FIG. 1 , and the set screw fittings are engaged upon such that the shaft  12  remains in place within the end brackets  70 . Subsequently, the incline sheets  40  are attached to the brackets  20  and  24 , as described above. 
     To raise the ramp assembly  10  from the lowered position, as shown in  FIG. 2 , to the raised position, as shown in  FIG. 3 , a pry bar  60  is used. The pry bar  60 , may have a square or any other cross-sectional construction, and extends between first to second ends,  62  and  64 , respectively, with a bend  66 , therebetween. The distance between the first end  62  and the bend  66  is such that the pry bar may be engaged upon the shaft  12  at the first end  62  and upon the pivot shaft  26  at the bend  66  when inserted into the pivot gap  28  from below. The pry bar pivot angle  68  may be such as, by way of non-limiting example, in the range of 120 to 150 degrees, such that the pry bar  60  may be easily inserted into the pivot gap  28  from below. While retaining engagement with the shaft  12  and the pivot shaft  26 , the second end  64  of the pry bar  60  is lifted and rotated in the direction generally indicated at  206  until the ramp assembly  10  is in the raised position, as illustrated in  FIG. 3 . It will be appreciated that the bend permits the pry bar to engage both of the shaft  12  and the pivot shaft  26  as well as preventing slipping upon the pivot shaft  26 . 
     Turning now to  FIG. 4 , the ramp assembly  10  is shown in the raised locked position. The pry bar  60  is then removed from the ramp assembly  10  prior to installing the lock  120  and base support  140 . The lock  120  comprises a lock body  122  having a square or any other suitable cross-sectional construction extending between top  124  and bottom  126 . A half cylinder sleeve  128  extends from the lock body  122  proximate to the top  124  and a threaded adjustable displacement bolt  132  and nut  134  extend from the lock body  122  below the half cylinder sleeve  128  proximate to the bottom  126 . The lock body  122  is sized to fit with the pivot gap  28  such that the lock  120  engages upon the pivot shaft  26  and the shaft  12 . The half cylinder sleeve  128  is attached to the lock body  122  proximate to the top  124  and is sized such that the diameter of the pivot shaft  26  fits within the inside diameter of the half cylinder sleeve  128 . A handle  130  is attached to the lock body  122  proximate to the top  124  on the opposite side of the body from the half cylinder sleeve  128 . The handle  130  is sized to be grasped by a user. Although the handle is shown as ring in the present embodiment of the invention, it may be appreciated that other shapes may be useful, as well. A nut  134  is attached to the lock body  122  proximate to the bottom  126 , below the half cylinder sleeve, perpendicular to the cylinder sleeve axis, which is aligned with the pivot axis  102 , with a transverse bore passing through the lock body  122  at the nut location such that the bolt  132  may be adjusted within the nut  134  and the lock body  122  to allow a variable length of exposed bolt  132 . To engage the lock  120  in position, the lock  120  is positioned in the pivot gap  28  with the half cylinder sleeve  128  engaged with the pivot shaft  26  and the lock body  122  positioned between the shaft  12  and the exterior wall  5  of the container  8 . It will be appreciated that the length of the bolt  132  may be adjusted such that the head of the bolt engages upon the wall  5 , thereby locking the ramp assembly  10  into position and preventing accidental disengagement of the assembly. 
     For additional support, a base support  140  may be positioned under the shaft  12 . The base support  140  is a screw jack, as is commonly known, with a half cylinder sleeve at the top sized to receive the shaft  12 . The base support  140  may be adjusted in height, as is commonly known, such that it engages upon both the ground  2  and the shaft  12 . 
     While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.