Patent Publication Number: US-7222838-B1

Title: Collapsible vehicle ramp

Description:
REFERENCE TO DISCLOSURE DOCUMENT CERTIFICATE 
   Reference is made to U.S. Disclosure Document Certificate No. 587734, recorded Oct. 5, 2005, entitled “Foldable Car Ramp”. The entire contents of such disclosure document is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention is related to the field of vehicle accessories, and more particularly to a device for supporting the wheels of a vehicle in a raised position, primarily to permit inspection, repair, and/or maintenance of the underside of the vehicle. 
   2. Brief Description of the Prior Art 
   Prior art vehicle ramps are generally in the nature of a fixed structure of steel plates and connecting steel braces. 
   An example of such a prior art vehicle ramp is a structure that comprises a sloping metal plate welded to a raised horizontal plate, with a steel frame welded, or otherwise secured, to the rear of the raised horizontal plate, and to the front sides of the sloped plate. 
   There are a number of prior art folding vehicle ramps, most of which fold along a longitudinal center of the ramp, and, in the unfolded condition, are simply a flat, or bowed rectangular surface end-to-end. 
   One prior art vehicle ramp is foldable, but the sloped ramp and horizontal wheel supporting plates are permanently joined together, as by welding, and is foldable only to the extent that the unitary ramp and wheel support plate folds relative to the frame that supports it. As a result, even in the folded condition, the device is bulky and occupies a significant amount of storage space in a garage, or in the trunk of a vehicle. 
   Accordingly, there is a need in the art for an improved vehicle ramp that is fully collapsible to occupy a minimum amount of storage space. 
   SUMMARY OF THE INVENTION 
   The present invention provides a vehicle ramp comprising a pair of plate members, pivotally connected together along respective edges thereof. A frame arrangement is articulately connected to the plate members, whereby the plate members can be selectively pivoted with respect to one another to either form a functional raised in-use vehicle ramp configuration, or form a storable, collapsed, low profile configuration in which the two plate members lie in substantially a common plane. 
   In a preferred embodiment, there is provided a vehicle ramp comprising a first plate member having a front end and a rear end, and a second plate member having a front end and a rear end. The rear end of the second plate member is pivotally connected to the front end of the first plate member. A frame arrangement, comprised of a plurality of interconnected articulated support members is provided, coupled to the first and second plate members, to permit collapsing the entire assembly from a raised in-use position. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     Further objects and advantages and a better understanding of the present invention may be had by reference to the following detailed description taken in conjunction with the accompanying drawings in which: 
       FIG. 1  is a perspective view of a collapsible vehicle ramp, shown in the raised, or in-use, condition, constructed in accordance with a preferred embodiment of the present invention; 
       FIG. 2  is a right side elevation view of the collapsible vehicle ramp shown in  FIG. 1 , the left side elevation view being a mirror image thereof; 
       FIG. 3  is a front elevation view of the collapsible vehicle ramp shown in  FIG. 1 ; 
       FIG. 4  is a rear elevation view of the collapsible vehicle ramp shown in  FIG. 1 ; 
       FIG. 5  is a top plan view of the collapsible vehicle ramp shown in  FIG. 1 ; 
       FIG. 6  is a bottom view of the collapsible vehicle ramp shown in  FIG. 1 ; 
       FIG. 7  is a perspective view of a collapsible vehicle ramp, shown in the collapsed condition, constructed in accordance with a preferred embodiment of the present invention; and 
       FIG. 8  is a right side elevation view of the collapsible vehicle ramp shown in  FIG. 7 , the left side elevation view being a mirror image thereof. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In  FIG. 1 , the collapsible vehicle ramp  1  is shown, in perspective representation, in its raised, or in-use configuration. 
   A riser plate member  2 , hereinafter referred to as riser  2 , extends from a reference surface, assumed to be the ground or floor in most cases, to an elevated level, leading to elevated wheel platform plate member  5 , hereinafter referred to as platform  5 . 
   Riser  2  comprises a flat friction plate portion  4  extending between a pair of parallel, U-shaped, raised, riser side channels  3 . 
   Platform  5  also comprises a flat friction plate portion  7  extending between a pair of U-shaped platform side channels  6 . 
   It will be understood that the raised diamond grip elements  12 , on the two flat friction plate portions  4  and  7 , are exemplary only of a frictional surface texture, are not necessarily shown to scale, and may not be depicted in the drawing as they would appear on the actual device. 
   In a preferred embodiment, the plate portion  4  and side channels  3  of the riser  2  are integrally formed as a unitary structure. Similarly, the plate portion  7  and side channels  6  of the platform  5  are integrally formed as a unitary structure. 
   An articulated frame structure  8 - 11  is preferably comprised of a pair of parallel, spaced-apart, horizontal angle iron base support members  8 , a back plate  9  with side flanges  10 , and a pair of parallel, spaced-apart, pivotable, vertical support members  11 . 
   Support members  11  are pivotally attached to respective base support members  8  by means of bolt and nut arrangements  13 , and similarly pivotally attached to the side channels  6  by means of bolt and nut arrangements  15 . 
   The side flanges  10  of back plate  9  are pivotally attached to respective base support members  8  by means of bolt and nut arrangements  17 , and similarly pivotally attached to the side channels  6  by means of bolt and nut arrangements  19 . 
   Each bolt and nut arrangement  13 ,  15 ,  17 ,  19  has a limited tightening span, and may have loose spacer sleeves to assist in aligning up the individual members of the articulated frame structure  8 - 11 , noting that the bottom of flanges  10  fit inside the vertical wall of horizontal base support member  8 , while vertical support members  11  fit on the outside. 
   A stud, preferably in the form of a bolt and nut combination  21 , is fixed adjacent the front end of riser  2  and is sized and shaped to fit snugly into a slot  23  formed in the front end of horizontal base support member  8 . In the raised in-use configuration of the vehicle ramp shown in  FIG. 1 , stud  21  is captured by, and securely retained in, slot  23 , due, in part, to the gravitational pull downwardly of the heavy steel riser  2 , and due, in part, to the tension in springs  25  (to be described in detail hereinafter). 
     FIG. 2  is a right side elevation view of the collapsible vehicle ramp  1  shown in  FIG. 1 , the left side elevation view being a mirror image thereof. In this view, it will be noted that the vertical support member  11  and back plate  9  lean slightly forward. This is intentional, as this configuration of the elements of the ramp  1  increases the stability of the raised, in-use, vehicle ramp  1 . If the vertical support member  11  and back plate  9 , in the raised configuration, were vertical, there may be a tendency for the ramp  1  to collapse under the weight of the vehicle on the platform  5 . 
     FIGS. 3 and 4  are, respectively, a front elevation view and a rear elevation view of the collapsible vehicle ramp  1  shown in  FIG. 1 . In these views, it will be observed that the bolt and nut arrangements  13 ,  15 ,  17 ,  19  are designed and selected to allow free pivoting of the articulated frame structure  8 - 11  with the platform  5 . 
     FIG. 5  is a top plan view of the collapsible vehicle ramp shown in  FIG. 1 . 
     FIG. 6  is a bottom view of the collapsible vehicle ramp shown in  FIG. 1 , revealing a number of small angle iron ribs  27 . Preferably, ribs  27  are welded, at each end of each rib  27 , to the outer walls of channels  3  and  6 , and welded, adjacent each end of each rib  27 , to the underside of the flat riser friction plate portions  4  and  7 . 
   Also, as seen in  FIG. 6 , a pair of tension springs  25  are provided. Each spring  25  is attached to, and stretched between, respective ones of a pair of laterally projecting studs  29  on back plate  9  and side channels  6 . 
   In  FIG. 6 , a steel stabilizing strap  33  is shown, welded at its ends to horizontal support members  8 , for rigidly coupling the free ends of horizontal support members  8  together at the proper spacing. 
   Springs  25  are in their relaxed state, since the vehicle ramp  1  is shown in its raised in-use configuration. It thus can be appreciated that the springs  25  assist in biasing the ramp  1  to get into, and stay in, the raised in-use configuration, a key safety feature of the invention. 
   As best understood by referencing  FIGS. 2 and 6 , when stud  21  is withdrawn from slot  23 , and a forwardly directed force is applied to the top of back plate  9 , springs  25  will be tensioned as the platform  5  moves forward, until the ramp  1  is in its fully collapsed configuration. In this condition, the springs  25 , although fully tensioned, are substantially parallel to the linearly aligned riser  2  and platform  5 , and therefore pull against a rigid resistance presented by the structure. With appropriate placement of the projecting studs  29 ,  31 , defining an over-center condition when the ramp  1  is in the collapsed configuration, the springs  25  will act to pull back plate  9  toward the front of the ramp  1 , and keep the ramp  1  in the collapsed condition. 
   When back plate  9  is lifted a small amount, from the collapsed condition of the ramp  1 , the springs  25  again act to pull the back plate  9  and platform  5  together and force the structure to a raised in-use condition. 
     FIG. 7  is a perspective view of the collapsible vehicle ramp  1 , shown in the collapsed condition; and  FIG. 8  is a right side elevation view of the collapsible vehicle ramp  1  shown in  FIG. 7 , the left side elevation view being a mirror image thereof. 
   While only certain embodiments have been set forth, alternative embodiments and various modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of the present invention.