Abstract:
A foldable ramp for use with vehicles wherein the ramp has a base with an arch plate for eliminating the step up to the ramp surface and an arched bridge to eliminate the step from the top of the ramp to the bed of a vehicle. A foot at the end of the arched bridge is pivotable and allows the ramp to engage the vehicle bed with a flat portion for stably engaging the truck. An adjustable belt connected between the vehicle and the ramp secures the ramp to the vehicle and prevents slipping. The ramp is foldable along its length for ease of storage. The ramp may have one bi-fold ramp for a short wheelbase use or narrow need uses, a tri-fold ramp for wider wheelbase use or two separated bi-fold ramp sections for wide wheelbase uses.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to folding ramps for moving items into or out of the bed of a pickup truck or other utility vehicle, to platforms, or up stairs, and to a hinge assembly, which prevents separation when the ramp sections are deployed in side-by-side arrangement. 
   2. Description of the Related Art 
   Many items to be transported in trucks, pick-up trucks, vans, sport utility vehicles, trailers, or other vehicles need to be lifted by the use of a ramp to get the cargo into or out of the vehicle. For example a two-wheel hand truck may be used to carry the cargo to the vehicle and with the use of a ramp can be used to lift the cargo into the vehicle. Similarly, All Terrain Vehicles (ATVs), motorcycles, other wheeled vehicles, or snowmobiles can use the ramps to be lifted into the vehicle. The ramps can also be used to lift or lower a cargo from loading docks, to the ground or to a vehicle, or to bridge stairs. 
   There are a number of ramp designs for use with vehicles. Some are foldable lengthwise, others are foldable widthwise. The folds are made with hinges having pins therein. Some ramps have plates at one end to act as a ramp for eliminating the step at the end of the ramp. Some ramps are connected to the vehicle at the bumper, others at a trailer hitch and others have cables or chains connected to one end of the ramp to secure the ramp to the vehicle. 
   For storage it is desirable if the ramp came in sections which when folded are easily stored and when unfolded make the ramp wider or longer. The ramp should also have guides on either side of the ramp for keeping wheels from sliding over the edge of the ramp. The ramp should also be easy to assemble and dissemble. The ramp should have a transition plate on the top and the bottom of the ramp for making it easier to wheel a load up the ramp. The ramp should be able to be used at different angles, and have a plate at the end of the ramp, which is adjustable for the different angles, to rest on the vehicle. 
   SUMMARY OF THE INVENTION 
   The invention relates to a foldable ramp having longitudinal sections for attachment to a vehicle. The sections can be used together or independently. When used together two or three sections can be hinged along the longitudinal length. The hinged connection allows for folding along the longitudinal edge for storing the ramp when not in use. 
   Short transitional ramps at either end of the ramp eliminate steps to reach the top or bottom of the ramp. The top transitional ramp has an optional pivotable foot for laying flat on the bed of the truck for a more stable ramp to truck engagement no matter what the angle of incline of the ramp. 
   The ramp is secured to the vehicle by an adjustable length strap from under the ramp to the bumper of the vehicle. 
   The ramp comprises two different rail types, an inside rail and an outside rail. The outside rail has a guide for inhibiting small diameter wheels of a vehicle on the ramp from falling over the edge of the ramp. The inside rail is designed to be inverted to be used symmetrically such that a connecting slot for a hinge can be either on the top or on the bottom of the inside rail depending on the folding direction desired for the ramp sections. 
   The ramps are generally used as either a single bi-fold, as a double spaced apart bi-fold or a tri-fold design. The single bi-fold ramp can be used for short wheelbase uses such as hand trucks or single wheel uses such as motorcycles, wheel barrows etc. The double bi-fold ramp can be used in pairs with wider wheelbase loads transported on the ramps such as All Terrain Vehicles. The tri-fold ramp three section ramp design is used for wider wheel bases than the single bi-fold ramp but not as wide a wheelbase as the double spaced apart bi-fold ramps. It is contemplated that the ramps will be used for loads such as lawn movers and garden equipment or for motorcycles, snowmobiles, wheelbarrow, barrels, All Terrain Vehicles or other wheeled vehicles. 
   OBJECTS OF THE INVENTION 
   It is an object of the invention to provide a light weight yet strong foldable ramp for use with vehicles such as pickup trucks. 
   It is an object of the invention to eliminate the step at the top and bottom of the ramp. 
   It is an object of the invention to provide an easy connection from the ramp to the vehicle to prevent the ramp slipping out of position during loading. 
   It is an object of the invention to provide an easy to assemble ramp. 
   It is an object of the invention to provide an easy to use adjustable strap to connect the vehicle to the ramp. 
   It is an object of the invention to provide a low cost ramp. 
   It is an object of the invention to provide a ramp which can be used at a variety of angles of incline for different size vehicles. 
   Other objects, advantages and novel features of the present invention will become apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a perspective view of a pickup truck and two bi-fold ramps. 
       FIG. 2  shows a perspective view of a pickup truck and a bi-fold ramp. 
       FIG. 3  shows a perspective view of the outside rail of the ramp. 
       FIG. 4  shows a perspective view of the inside rail of the ramp. 
       FIG. 5  shows a perspective view of the tread plate, arch bridge and foot of the ramp. 
       FIG. 6  shows a cross sectional view of a bi-fold ramp extended. 
       FIG. 7  shows a cross sectional view of a bi-fold ramp folded. 
       FIG. 8  shows a cross sectional view of a tri-fold ramp extended. 
       FIG. 9  shows a cross sectional view of a tri-fold ramp folded. 
       FIG. 10  shows a bottom perspective view of a ramp section with the top of the ramp section at the left of the drawing. 
       FIG. 11  shows a bottom perspective view of a ramp section with the top of the ramp section at the right of the drawing. 
       FIG. 12  shows the adjustable strap used for connecting a ramp section to the bumper of a truck 
       FIG. 13  shows a cross section of the arched bridge and pivoting foot of the ramp. 
       FIG. 14  shows a perspective view of the hinge connecting two inside rails of the ramp. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   There is a need for ramps to raise and lower goods from trucks or trailers to the ground or to loading docks. Frequently a portable ramp is required to be carried in a truck for such uses and it is desirable if the ramp folds for easy storage in the truck.  FIG. 1  shows a pick up truck  20  having its tailgate  24  down and a pair of bi-fold ramps  10  extending from the ground to the tailgate  24 . The configuration of the two bi-fold ramps being spaced apart suggests the use as being for rolling wider wheel base objects into and out of the truck such as an All Terrain Vehicle. Although  FIG. 1  shows two bi-fold ramps in use a single bi-fold ramp may be used for many purposes such as hand trucks where there is a narrow wheelbase. In  FIG. 2  a tri-fold ramp  15  is shown used with the pickup truck  20 . The tri-fold ramp  15  is wider than the bi-fold ramp such that a shorter wheel base device can use the ramp without having to adjust the position of two ramps for the wheels of the vehicle. The tri-fold ramp may be useful for lawn mowers, riding lawn mowers, wheelbarrows, motorcycles, snowmobiles, carts, hand trucks, barrels and other uses. 
   Both the bi-fold ramps  10  and tri-fold ramps  15  are composed of ramp sections  100 ,  110 ,  120  and  130 . Each ramp section  100 ,  110 ,  120  and  130  has a ground arch plate  90  having a rounded nose portion  92  and an angled portion  94  on the top for acting as a ramp from the ground to the flat top portion  96 , which is integral with the tread plate  50  on top of the ramp section  100 . The symmetric angled portion  94  on the bottom of the ground arch plate  92  rests on the ground. In this manner the ramp  10 ,  15  has the bottom of the angled portion  94  resting on the ground with the rounded nose  92  allowing a gradual increase for a wheel traversing the end of the ramp section  100 ,  110 ,  120  and  130 . The nose portion  92  transitions to an angled portion  94  leading to the top of the ground arch plate  90  for transitioning from the rounded nose  92  to the tread plate  50  at an angle such that the combination of the rounded nose  92  and the angled portion  94  avoids the step from the ground to the tread plate  50  making it easier to wheel an object up the ramp  10  and avoids bumps when lowering an object down the ramp  10 . 
   Ramp sections  100 ,  110 ,  120  and  130  also have a tailgate engaging portion  80 , as best seen in  FIG. 13 , having an arched bridge portion  81  which forms a ramp from the top end of the ramp section  100 ,  110 ,  120  and  130  tread plate  50  to the tailgate  24  of the pickup truck  20 . The bridge portion  81  ends with a cylindrical rail  86  which may optionally have a pivoting foot  82  with a groove  84  for sliding onto the cylindrical rail  86 , such that the pivoting foot  82  can lay flat on the tailgate  24  and provides a ramped upper surface which in combination with the arched bridge portion  81  eliminates the step from the step from the top of the tread plate  50  to the tailgate  24 . Optionally a rubber pad  83  can be used on the base of pivoting foot  82  for a surer grip on the tailgate  24  of the pickup truck. For the case where the pivoting foot is not used a rubber padding  87  can optionally be used at the end of arched bridge portion  81  to rest on the pickup truck  20  tailgate  24  to prevent scratching the paint on the tailgate. 
   Ramp sections  100 ,  110 ,  120 ,  130  can be combined into two types of ramps. One type is a bi-fold ramp  10  which has an outside rail  30 , shown in  FIG. 3  combined with an inside rail  40  as shown in  FIG. 4 , and a tread plate  50  attached at the top of the outside rail  30  and the inside rail  40 . The bi-fold ramp combines a ramp section  100  with a ramp section  110  to form the bi-fold ramp. Ramp section  100  is the mirror image of ramp section  110  with the rails  30  and  40  being reversed. The other type of ramp is a tri-fold ramp  15 . It has two inside rails  40 , one inside rail  40  being upside down and backwards form the other, plus a tread plate  50  on top of the rails  40 , as best seen in  FIG. 8 . Hinges  60  are used for connecting the ramp sections  100  so that they fold as shown in  FIGS. 7 and 9 . The tri-fold ramp is composed of ramp section  100 ,  120  and  130  where ramp section  120  has rails  40  on either side of the tread plate  50  with one rail  40  being inverted from the other rail  40  and ramp section  130  differing from ramp section  120  in the bi-fold ramp in that it has an inverted rail  40 . 
   As shown in  FIG. 3  the outside rail  30  has a flange or guide  32  for preventing a wheel from rolling off the edge of ramp sections  100 ,  110  or  130 . The outside rail  30  also has a groove  34  in the top for accepting the flange  54  of tread plate  50 . Similarly the inside rail  40  has a groove  42  at the top of the inside rail  40  for accepting the flange  54  of tread plate  50 . The bottom of rail  40  also has a groove  44  for accepting the flange of a tread plate  50  when the inside rail  40  is inverted. The top of the inside rail  40  also has a circular groove  46  for receiving a circular rail  64  on a hinge  60 . The hinge  60  allows two adjoining ramp sections  100 ,  110  or  100 – 120  or  120 – 130  to fold relative to each other, see  FIGS. 6–9 . The hinge  60  can come in a variety of lengths and multiple hinges  60  can be used along the length of the ramp sections  100 ,  110 ,  120  and  130 . The end hinge  60  can have screws  62  threaded into the ends of the circular rail  64  to expand the circular rail  64  and tighten it into place in the circular groove  46  of the inside rail  40  to help ensure the hinge  60  will stay in place. The hinge  60  is preferably made form an elastic material such as rubber, which is flexible and durable. 
   As shown in  FIG. 6  the left rail  30  has a guide  32  on the left side of the ramp section  100  and the right rail  30  has the guide  32  on the right side of the ramp section  110  by turning the rail  30  around. 
   As shown in  FIG. 8  the tri-fold ramp middle section  120  has inverted inside rails  40  on one side of ramp section  120  to provide a folding hinge  60  on the top of the left hand ramp section  120  and a hinge on the bottom of the right hand ramp section  120 . When folded, the ramp sections  100 ,  120 ,  130  will stack as shown in  FIG. 9 . 
   To construct ramp sections  100 ,  110 ,  120  and  130  two rails  30 ,  40  are spaced apart and tread plate  50  with flanges  54  is inserted in the grooves  34 ,  42  or  44  of rails  30  and/or  40 . To perform this operation tread plate  50  is inverted such that the flanges  54  are extending upward, one outside rail  30  having flange  54  in groove  34  and one inside rail  40  having flange  54  in either groove  42  or  44 . Ribs  52  are then set on the tread plate  50  between the rails  30 ,  40  or  40 ,  40 . The ribs  52  are then welded to the tread plate  50  and the rails  30 ,  40  or  40 ,  40 . The ribs  52  add strength to the ramp and secure the tread plate  50  to the rails. Any number of ribs  52  may be used depending on the required strength of the ramp the length of the ramp, the width of the ramp, the materials used and other factors. 
   Tread plate  50  also has a bracket  58  welded to the underside thereof on ramps sections  100 ,  110  and  130 . Bracket  58  has apertures  158  for adjustably engaging webbing on a belt  70  which is threaded therethrough. As seen in  FIG. 12 , the belt webbing  70  adjustably passes through apertures  174  on male buckle  74  and the adjustably passes through apertures  176  on female buckle  76  to form a tension loop  72  between the male buckle  74  and the female buckle  76 . The webbing continues from the apertures  176  on female buckle  76  to and adjustably passes thought the apertures  173  on vehicle hook  73 . In this manner the ramp sections  100 ,  110  and  130  are attached to the bumper  26  of vehicle  20  and secured thereto so that the ramp sections  100 ,  110  and  130  will not slip once put in place and a load can safely be transported up bi-fold ramp  10  or tri-fold ramp  15 . Although a the belt  70  is shown with male and female buckles  74  and  76  and four different adjustable connections  158 ,  173 ,  174 ,  176 , any means for connecting the ramp sections  100 ,  110 ,  120  and  130  to the vehicle can be used. For example only one adjustment as at  158  need be used on a strap  70  and a vehicle hook  73 . In general a tension adjustment of any type may be used on the belt  70  anyplace along belt  70  between bracket  58  and vehicle hook  73 . 
   The tread plate  50  preferably has apertures  56  in the surface to lighten the ramp sections  100 . The apertures  56  preferably have rims  18  to improve traction on the ramp and to add stiffness and strength the tread plate  50 . 
   The tread plate  50 , rails  30  and  40  and ribs  52  are preferably made out of aluminum for a light weigh yet strong ramp. The ramp sections  100 ,  110 ,  120  and  130  are preferably on the order of 1.75 to 2.5 meters in length. The rails  30  and  40  are preferably made from extruded aluminum. The ramp sections  100 ,  110 ,  120  and  130  as shown support approximately 340 kilograms. 
   The foldable ramps for use primarily for pickup trucks, vans, trucks or other vehicles are shown in the figures in bi-fold and tri-fold embodiments however the ramp sections  100 ,  110 ,  120  and  130  can be used one at a time or in any number of linked ramp section combinations. Further, although the ramps are shown used with pickup trucks, other uses such as loading docks, stairs, trailers or other vehicles are possible for the ramps. 
   Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.