Abstract:
A collapsible, portable ramp assembly, made of light weight materials and of a unitized construction whereby all components are a permanent part of the assembly, and which can be quickly and easily deployed to form a sturdy ramp for a variety of uses. The central, load-bearing portion of the ramp is formed by many light weight, transversely positioned slats, pivotally connected to one another by several flexible straps. Rigid support of the central ramp portion is provided by a pair of strong, light weight braces that simply rotate into a longitudinal position along the ramp sides from their position along the ramp end pieces.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     None 
     STATEMENT REGARDING FEDERAL SPONSORED R &amp; D 
     None 
     REFERENCE TO A “MICROFICHE APPENDIX 
     None 
     BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     The use of ramps by vehicles and others to bridge obstacles is well known. Their shape, size, weight and portability is usually of little concern in the industrial environment. This is not true, however, to the handicapped or elderly user, since their ability to handle such conditions is severely limited. The ability to personally carry, deploy and return to storage, is a major factor in their independence. 
     Much of the prior art gives only partial consideration to the above concerns. In the past, when attention is given to ease of storage, we find it necessary to store several components separately, thereby increasing the risk of losing some of the components. When consideration is given to unitized construction, we are left with a large, heavy and cumbersome ramp that is difficult to store. 
     The prior art cited below exhibit these limiting factors. We will show that by attention to detail, a ramp overcoming these limitations can be inexpensively produced. 
     The present invention relates to collapsible, portable ramps of a unitary construction that are particularly suitable for use by, but not limited to, wheelchairs and other vehicles commonly used by the disabled, elderly or other persons requiring transportation assistance. 
     2) Description of Related Art 
     Everard et al. U.S. Pat. No. 5,347,672 disclosed a “portable, stowable knock-down ramp” in which one or more separate side rails must be attached to a central platform made from a series of interlocking metal extrusions. While providing the basic function of bridging a curb or a series of steps, the Everard et al. ramp construction is cumbersome to use due to the size and weight of key components, and due to the fact that ramp plates must be precisely inserted and locked into the side rail for proper and safe use. Also, the fact that the side rails are carried separately, increases their risk of loss and damage during storage. 
     Estes et al. U.S. Pat. No. 5,933,898 discloses a “portable wheelchair ramp” which provides a knock-down ramp in which a series of interconnected spanning panels are deployed and locked together to form the basic function of bridging a curb or a series of steps. The Estes et al. ramp construction is cumbersome to use due to the size and weight of key components and due to the fact that the spanning panels must be locked together for proper and safe use. 
     SUMMARY OF THE INVENTION 
     1) Objectives and Advantages 
     The present invention provides a collapsible, portable ramp assembly, made of light weight materials and of a unitized construction whereby all components are a permanent part of the assembly, and which can be quickly and easily deployed to form a sturdy ramp for a variety of uses. Due to its unique construction, the portable ramp may be easily broken down without the need for component removal. It may also be rolled up into a single, small, compact package for carrying in a tote-bag. 
     In the preferred embodiment, the central, load-bearing portion of the ramp is formed by many light weight, transversely positioned slats, pivotally connected to one another by several flexible straps. Rigid support of the central ramp portion is provided by a pair of strong, light weight braces that simply rotate into a longitudinal position along the ramp sides from their position along the ramp end pieces. When no longer in use, the braces are rotated back and locked into their transverse position along the end pieces of the ramp for easy storage. Since the braces need not be removed or re-attached to the central ramp portion of the assembly, the ramp is easily roll up into a single package for storage in a tote-bag suitable for hanging on the back of a wheelchair, or similar vehicle. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The details and many of the advantages provided by this invention will become clear and will be better understood by reviewing the following description and accompanying drawings, wherein: 
     FIG. 1 is a top perspective view of a collapsible, portable ramp assembly according to the present invention in a position of bridging a set of stairs. 
     FIG. 2 a  is an underside view of the collapsible, portable ramp showing the relationship between in a fully deployed position. 
     FIG. 2 b  is a detailed side view of the ramp top piece and top plate properly placed over a curb or step corner. 
     FIG. 2 c  is a detailed side view of the ramp bottom piece and bottom plate properly placed on a typical approach. 
     FIG. 3 is an underside view of the collapsible, portable ramp showing the first embodiment relationships between the telescoping braces and other ramp components in a non-deployed position. 
     FIG. 4 is a side view of the collapsible, portable ramp in its rolled up and tied position. 
     FIG. 5 is an underside view of the collapsible, portable ramp showing the second embodiment relationships between the “Z” braces and other ramp components in a non-deployed position. 
     FIG. 6 is an underside view of the collapsible, portable ramp showing the third embodiment relationships between the folding braces and other ramp components in a non-deployed position. 
    
    
     DETAILED DESCRIPTION 
     A collapsible, portable ramp assembly, FIG. 1, as described in the present invention includes a central portion formed of a top piece  18  and a bottom piece  20 , and having there between, a plurality of ramp slats  10 , all made of light weight, but strong material such as for example aluminum alloy, steel, plastic, carbon fiber, or wood, and held together by a plurality of flexible, strong straps  12  made of a suitable flexible material such as for example leather, webbing, ribbon, or plastic. Each slat  10  has a turned up edge  16  to prevent lateral tracking of the vehicle off the ramp. Alternating slats  10  are offset on one side or the other to allow a tighter roll when the ramp is stored. A non-skid surface  30  may be added to improve traction. 
     As shown in FIG. 2 a , each strap  12  is attached to the underside of the top piece  18  and the bottom piece  20 , and to the underside of each slat  10 , using rivets  14  or other suitable fasteners. Further, the top piece  18  is attached to a top plate  26  by a top hinge  22 , and the bottom piece  20  is attached to a bottom plate  28  by a bottom hinge  24 . As shown in FIG. 2 b , the top plate  26  is “L” shaped and is made of light weight, but strong material such as for example aluminum alloy, steel, plastic, carbon fiber, or wood, and has its edge opposite the top hinge  22 , tapered to match the curb or step landing surface. The top plate  26  is designed to fit against the corner of the curb or step. As shown in FIG. 2 c , the bottom plate  28  is flat shaped and is made of light weight, but strong material such as for example aluminum alloy, steel, plastic, carbon fiber, or wood, and has its edge opposite the bottom hinge  24 , tapered to match the approach surface. A non-skid surface  30  may be applied to the underside of the top plate  26  and the bottom plate  28  to prevent slippage where they contact their respective landing and approach points. 
     Further shown in FIG. 2 a , a pair of braces  32 , having one end permanently attached to the central portion of the ramp, and made of light weight, but strong material such as for example aluminum alloy, steel, plastic, carbon fiber, or wood, are located longitudinally on the underside of the ramp slats  10 , along each side of the ramp. When locked in their deployed position, the braces  32  and the ramp slats  10  form a ramp that is both flat and rigid, and that is suitable for bridging a curb, or one or more steps, and allowing a wheeled vehicle such as for example a wheelchair, cart or scooter, to proceed up or down said curb or steps. 
     In the preferred embodiment, FIG. 3, the ramp is provided with a pair of telescoping braces  42  and  43 , that are made of light weight, but strong material such as for example aluminum alloy, steel, plastic, carbon fiber, or wood, and are located on the underside of the ramp. The telescoping braces  42  and  43  are a permanent part of the collapsible, portable ramp assembly, and are shown in their stored position, a position transverse to the ramp direction and along the underside of the bottom piece  20  and the top piece  18 , respectively. During deployment, the telescoping braces  42  and  43  are extended in length and rotated through 90 deg. of travel to a longitudinal position along the underside of each side of the ramp. 
     The first telescoping brace  42  has a brace fixed end  34  and a brace detachable end  36 . By means of telescoping, the telescoping brace  42  has a minimum length equal to the ramp width and a maximum length equal to the ramp length. The telescoping brace  42  is locked in its minimum length and maximum length by a telescoping brace detent  44 . The telescoping brace  42  has its brace fixed end  34  permanently attached to the bottom piece  20  by a pivot pin  38  allowing it to rotate from its storage position to its deployed position. In addition, the telescoping brace  42  has its brace detachable end  34  attached to the bottom piece  20  by a locking pin  40 , thereby securing telescoping brace  42  in place during storage. During deployment, the telescoping brace  42  is detached from the locking pin  40 , located on the bottom piece  20 , and extended to its deployed length and rotated into its deployed position, where its brace detachable end  34  is re-attached to the top piece  18  by the locking pin  40 . The second telescoping brace  43  is permanently attached to top piece  18  and operates in a manner equal to that described above. 
     As shown in FIG. 4, the collapsible, portable ramp assembly with permanently attached telescoping braces  42  and  43  in their stored position, may be rolled up from one end, or from both ends, and may be retained by, for example, one or a plurality of latches, straps, belts or ties, made of, for example, plastic, metal, carbon fiber, leather, webbing, ribbon, or other suitable material. Once rolled up, the collapsible, portable ramp assembly may be placed in a tote bag, or similar carrying case, for easy storage. 
     In the second embodiment, FIG. 5, the ramp is provided with a pair of “Z” braces  46  and  47  made of light weight, but strong material such as for example aluminum alloy, steel, plastic, carbon fiber, or wood, and located on the underside of the ramp. The “Z” braces  46  and  47  are permanent part of the collapsible, portable ramp assembly, and are shown folded and in their stored position, a position transverse to the ramp direction, and along the underside of bottom piece  20  and top piece  18 , respectively. The “Z” brace  46  is shown in a semi-folded condition for clarity. During deployment, the “Z” braces  46  and  47  are unfolded into an elongated and straight condition, and rotated through 90 deg. of travel to a longitudinal position along the underside of each side of the ramp. 
     The first “Z” brace  46 , has a brace fixed end  34 , a brace detachable end  36 , and has a plurality of folding “Z” brace sections  46 , connected together by a plurality of “Z” brace hinge pins  48 . By means of folding and unfolding, the “Z” brace  46  has a minimum length equal to the ramp width and a maximum length equal to the ramp length, respectively. The “Z” brace  46  is locked in its minimum length and maximum length by a plurality of “Z” brace detents  50 . The “Z” brace  46  has its brace fixed end  34  permanently attached to the bottom piece  20  by a pivot pin  38 , allowing it to rotate from its storage position to its deployed position. In addition, the “Z” brace  46  has its brace detachable end  34  attached to the bottom piece  20  by a locking pin  40 , thereby securing it in place during storage. During deployment, the “Z” brace  46  is detached from the locking pin  40 , located on the bottom piece  20 , and is extended to its deployed length and rotated into its deployed position, where its brace detachable end  34  is re-attached to the top piece  18  by the locking pin  40 . The second “Z” brace  47  is permanently attached to the top piece  18  and operates in a manner equal to that described above. 
     As shown in FIG. 4, the collapsible, portable ramp assembly ramp with permanently attached “Z” braces  46  and  47  in their stored position, may be rolled up from one end, or from both ends, and may be retained by, for example, one or a plurality of latches, straps, belts or ties, made of, for example, plastic, metal, carbon fiber, leather, webbing, ribbon, or other suitable material. Once rolled up, the collapsible, portable ramp assembly may be placed in a tote bag, or similar carrying case, for easy storage. 
     In the third embodiment, FIG. 6, the ramp is provided with a pair of folding braces  52  and  53  that are made of light weight, but strong material such as for example aluminum alloy, steel, plastic, carbon fiber, or wood, and are located on the underside of the ramp. The folding braces  52  and  53  are a permanent part of the collapsible, portable ramp assembly, and are shown folded and in their stored position, a position transverse to the ramp direction, and along the underside of the bottom piece  20  and the top piece  18 , respectively. The folding brace  52  is shown in a semi-folded condition for clarity. During deployment, the folding braces  52  and  53  are unfolded into a straight condition, and rotated through 90 deg. of travel to a longitudinal position along the underside of each side of the ramp. 
     The first folding brace  52  has a brace fixed end  34 , a brace detachable end  36 , and has a pair of folding brace sections  52  connected together by a folding brace hinge  54 . By means of folding and unfolding, the folding brace  52  has a minimum length equal to the ramp width and a maximum length equal to the ramp length, respectively. The folding brace  52  is locked in its maximum length by a folding brace clasp  56 . The folding brace  52  has its brace fixed end  34  permanently attached to the bottom piece  20  by a pivot pin  38  allowing it to rotate from its storage position to its deployed position. In addition, the folding brace  52  has its brace detachable end  34  attached to the bottom piece  20  by the locking pin  40 , thereby securing it in place during storage. During deployment, the folding brace  52  is detached from the locking pin  40 , located on the bottom piece  20 , and is extended it to its deployed length and rotated into its deployed position where its brace detachable end  34  is re-attached to the top piece  18  by the locking pin  40 . The second folding brace  53  is permanently attached to the top piece  18  and operates in a manner equal to that described above. 
     As shown in FIG. 4, the collapsible, portable ramp assembly ramp with permanently attached the folding braces  52  and  53 , in their stored position, may be rolled up from one end, or from both ends, and may be retained by, for example, one or a plurality of latches, straps, belts or ties, made of, for example, plastic, metal, carbon fiber, leather, webbing, ribbon, or other suitable material. Once rolled up, the collapsible, portable ramp assembly may be placed in a tote bag, or similar carrying case, for easy storage.