Patent Publication Number: US-8118280-B2

Title: Modular vehicle ramp system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to and claims priority from earlier filed U.S. Provisional Patent Application No. 61/062,200, filed Jan. 25, 2008. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a vehicle ramp system for elevating all four wheels of a vehicle off of the ground to create clearance under the vehicle for a person to easily work therebeneath. More specifically, the present invention relates to a modular vehicle ramp system for elevating all four wheels of a vehicle off of the ground to create clearance under the vehicle wherein the ramp is reconfigurable with a vehicle positioned thereon to allow a user easy access beneath the elevated vehicle. 
     Typically in the art, portable car ramps are used for increasing vertical clearance beneath a vehicle. In this manner, the ramps are positioned on a flat horizontal garage floor, driveway, yard or like support medium, with the wheels of the vehicle elevated thereon so that a worker can repair or service the vehicle from the underside thereof. A typical portable car ramp includes a bottom structure that engages with a support surface in a stable manner, a generally level wheel support substantially parallel to but elevated above the support surface and an inclined surface that extends from the support surface upwardly to the wheel support. The vehicle wheel is then rolled up the inclined surface to the elevated wheel wherein the wheel of the vehicle is maintained in an elevated position thereby increasing the clearance beneath the vehicle providing access thereto. Should the user desire both that sides of the vehicle frame be elevated, two matching ramps are used, where either both front wheels or both rear wheels are simultaneously rolled up the respective ramps and onto the respective wheel supports. 
     Such ramps are typically constructed of formed steel, which is painted. This produces a strong, economical ramp but the ramps are relatively heavy. Another approach is to mold the ramps from plastic with internal webs extending between external walls of relatively thin width to achieve adequate strength. While lighter than steel, the plastic ramps are still heavy enough to not be easily handled. Further, these systems are typically not modular in construction and therefore do not provide flexibility in arrangement and use of the ramps. 
     In the prior art there are several modular wheel ramp assemblies disclosed such as in U.S. Pat. No. 4,920,596, which includes a two level ramp device composed of a first ramp segment attachable at a rear portion to a second ramp segment that itself includes a first support level, which is in turn attachable at a rear portion to a third ramp having a second support level for positioning a car wheel thereon. The design of the first and second ramps requires alignment end-to-end and assembly of the units by positioning each axially before connection to the respective pairs of end brackets. If a car wheel is driven onto the first ramp without the second and third ramps portion attached, the first ramp can “kick-out” or slide away from the wheel due to the limited bottom surface area contacting against the ground surface. Use of this type of ramp device requires assembly before a car wheel progresses to an elevated height to allow aligning of each rear portion of second and third ramps when unweighted to protect the user from “kick-out” by the ramp device. Further, this type of ramp device requires end-to-end alignment for proper cradling by the end brackets extended from each rear portion of each ramp segment, thereby posing an unsafe situation if the operator attempted to assemble or reconfigure the aligned ramp segments while a front or rear wheel is on a first ramp segment and is partially elevated above a ground surface. 
     A leveling ramp device for a vehicle tire is disclosed in U.S. Pat. No. 4,427,179, that includes a plurality of planar planks that are stacked with their front ends forming a stairway for a wheel to climb, and having rear ends enclosed by a back frame having side members enclosing side wall portions of each stacked plank. Each ramp plank is further held in place by a downwardly projecting dowel that is inserted in the top surface of the next lower ramp plank to maintain alignment of the front portions of the stacked ramp planks. The plurality of ramp planks must be aligned, stacked and enclosed by the back frame before a vehicle tire is moved up the front end surfaces, otherwise the planks will be pushed sideways or backwards without the back frame and interlocking dowels in place. A vehicle tire cannot be positioned in a partially elevated horizontal position other than on an uppermost surface and additional ramp planks must be added before the tire is initially positioned at the uppermost height. 
     Additionally, an elevating and leveling ramp device for a vehicle wheel is disclosed in U.S. Pat. No. 3,752,441, that is formed using a plurality of hollow blocks having step-like sections that are nestable within the next larger hollow block. The elevating and leveling ramp device allows for extension of each hollow block from the next larger block to form a series of steps on which a vehicle wheel is moved. During extension of respective hollow blocks from the next larger hollow block, the respective blocks are aligned and connected end-to-end, but are not laterally movable for disassembly while the vehicle wheel is positioned on any of the blocks. Therefore, any larger hollow blocks must be added to the ramp device before a vehicle wheel is moved on a low height block or on a middle height block. 
     In addition to the various problems identified above, another problem encountered in the prior art is the tendency for the bottom edges of the sidewalls of both the steel and molded plastic ramps to sink into gravel or earth surfaces or to be easily tipped when in use. Further, the edges of side walls of formed steel ramps can damage asphalt paving and the side walls of plastic ramps can be easily collapsed if the ramp is misaligned with the vehicle wheels to a degree that the tires push the ramp sideways, bending the same such that the walls collapse under the weight of the vehicle. 
     There is therefore a need for a modular ramp construction that can be reconfigured with the vehicle in place thereon to allow easier access to the underside of the vehicle. There is a further need for a lightweight but durable and stable modular ramp that is useable on softer surfaces and which can easily be rearranged into many different configurations. There is still a need for a modular ramp system that can easily be rearranged into many different configurations and is constructed using lightweight monolithic materials that are highly durable while also increasing the overall stability of the ramp system. 
     BRIEF SUMMARY OF THE INVENTION 
     In this regard, the present invention provides a vehicle ramp system for elevating all four wheels of a vehicle off of the ground to create clearance under the vehicle for a person to easily work therebeneath. Further, the present invention provides a modular vehicle ramp system for elevating all four wheels of a vehicle off of the ground to create clearance under the vehicle wherein the ramp is reconfigurable with a vehicle positioned thereon to allow a user easy access beneath the elevated vehicle. As a result a modular ramp system according to the present invention provides a very solid car ramp suitable for lifting a wide variety of vehicles, particularly vehicles with very low clearance. 
     As can be appreciated upon a reading of the following specification and claims, a multi-component ramp system is provided wherein each of the components is modular thereby allowing the ramp system to be employed in several different reconfigurable arrangements. In its simplest form, the ramp system includes at least one solid block core formed as a wheel support and at least one angled ramp that releasably engages with the wheel support. In another embodiment, at least two wheel supports are employed with two corresponding ramps releasably engaged therewith such that two vehicle wheels can be elevated simultaneously. Finally in another embodiment, the present invention employs four wheel supports positioned in spaced apart relation corresponding to the spacing of the wheels of the vehicle to be supported thereon. Two bridge sections extend between two of the wheel supports positioned at the front and two of the wheel supports positioned at the rear such that the bridge sections have an upper surface that is substantially level with the top surfaces of the wheel supports. At least two ramps are releasably engaged with either the two forward or rear wheel supports such that a car can be driven up the ramps and over the bridge sections such that the four vehicle wheels are supported on the four wheel supports. 
     In each of the embodiments, all of the components described above are preferably monolithically constructed using a lightweight composite comprised of an expanded foam plastic core, in particular, a expanded polystyrene foam which is encapsulated in a high tensile strength polyurea coating of sufficient thickness to provide a durable surface when cured and create a strong composite structure. The polyurea coating is preferably applied by spraying liquid components onto the foam plastic core so as to create a textured surface for good tire traction. The polyurea coating may optionally be top coated with a hard coat of an abrasion and water resistant color stable polyurea formulation. The combination of the core and high tensile strength polyurea coating creates a sufficiently strong and durable structure to be very well suited for use as a vehicle service ramp. In addition to the construction described above, the present invention may also be implemented using other lightweight laminates such as fiberglass, carbon fiber composites and composite nanomaterials. Further, each of the above may also include core supports in the form of wood and/or metal panels and/or bulkheads. 
     The block core can be easily and economically cut out in a great variety of shapes without requiring special tooling, with the polyurea thereafter applied as a coating as by spraying the block core to allow ramps of many configurations to be manufactured without incurring significant tooling costs. Very low angle approach ramps can be easily provided which are lightweight so as to be practical to use despite being of relatively long length. The solid footprint of the ramps of this construction creates a stable ramp that has a greatly reduced tendency to sink into soft surfaces. 
     For heavier duty designs, additional strengthening features can be employed to resist compressive loads. This may include one or more panels of plywood or other sturdy material such as plastic or metal, oriented on edge or layed flat within the core, braced by the presence of the expanded polystyrene foam of the core encasing the panels. 
     Therefore it is an object of the present invention to provide a modular ramp construction that can be reconfigured with the vehicle in place thereon to allow easier access to the underside of the vehicle. It is a further object of the present invention to provide a lightweight but durable and stable modular ramp that is useable on softer surfaces and which can easily be rearranged into many different configurations. It is still a further object of the present invention to provide a modular ramp system that can easily be rearranged into many different configurations and is constructed using lightweight monolithic materials that are highly durable while also increasing the overall stability of the ramp system. 
     These together with other objects of the invention, along with various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings which illustrate the best mode presently contemplated for carrying out the present invention: 
         FIG. 1  is a side view of a modular ramp system in accordance with a first embodiment of the present invention; 
         FIG. 2  is a front perspective view of the modular ramp of  FIG. 1 ; 
         FIG. 3  is a side view of a modular ramp system in accordance with a second embodiment of the present invention; 
         FIG. 4  is a front perspective view of the modular ramp of  FIG. 3 ; 
         FIG. 5  is a side view of a modular ramp system in accordance with a third embodiment of the present invention; and 
         FIG. 6  is a front perspective view of the modular ramp of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Now referring to the drawings, the modular ramp system is shown and generally illustrated in the figures. As can be seen a modular vehicle ramp system is provided for elevating from one to all four wheels of a vehicle off of the ground to create clearance under the vehicle wherein the ramp is reconfigurable with a vehicle positioned thereon to allow a user easy access beneath the elevated vehicle. As a result a modular ramp system according to the present invention provides a very solid car ramp suitable for lifting a wide variety of vehicles, particularly vehicles with very low clearance. 
     Turning now to the drawings,  FIGS. 1 and 2  depict in its simplest form a multi-component ramp system  10  wherein each of the components is modular thereby allowing the ramp system  10  to be employed in several different reconfigurable arrangements. The ramp system  10  includes at least one wheel support  12  having a top support surface  14  and an engaging surface  16  on a front face  18  thereof. Further, at least one ramp  20  can be seen positioned adjacent the front face  18  of the wheel support  12  wherein the ramp  20  is releasably engaged with engaging surface  16  formed therein. The ramp  20  further includes a ramp surface  22  that extends upwardly to the top support surface  14  on the wheel support  12 . The engaging surfaces are shown here as corresponding male and female keyway formations but may alternately be pins, grooves, channels, dovetails or any other suitable mating formation know in the art. Furtherwhile the engaging surfaces are shown as being oriented horizontally, any other orientation such as vertical or oblique would equally fall within the spirit and scope of the present invention. 
     Turning to  FIGS. 3 and 4 , the wheel support  12  can be seen to include a second engaging surface  24  on a rear surface  26  thereof. This second engaging surface  24  is formed to be modular and of the same size and configuration as the first engaging surface  16  at the front of the wheel support  12 . In these figures the rear engaging surface  24  can be seen to receive and retain a wheel stop  28 . The wheel stop  28  is provided to prevent a vehicle wheel positioned on the support surface  14  from rolling too far forward such that it rolls completely off of the support surface  14 . Additionally, however, the wheel stop  28  can be removed and the ramp  20  can be repositioned to allow the vehicle to be taken down from the support surface  14  by continuing in a forward direction as desired by the user. 
     It should be appreciated that the structures shown in the previous figures may simply be duplicated such that at least two wheel supports  12  are employed with two corresponding ramps  20  releasably engaged therewith such that two vehicle wheels can be elevated simultaneously. In this regard the two wheel supports  12  and two ramps  20  are positioned in spaced apart relation based on the spacing of wheels on a vehicle to be supported thereon. In this regard both front wheels, both rear wheels or both wheels along one side of the vehicle can be simultaneously elevated. 
     Turning now to  FIGS. 5 and 6 , in another embodiment, the present invention employs two wheel supports  12 ,  12   a  positioned in spaced apart relation corresponding to the spacing of the wheels of the vehicle to be supported thereon. A bridge section  30  is provided that extends between the wheel supports  12 ,  12   a  such that one of the wheel supports  12  is at the front of the bridge section  30  and one of the wheel supports  12   a  is positioned at the rear of the bridge section  30 . The bridge section  30  can be seen to include an upper surface  32  that is substantially level with the top support surfaces  14  of the wheel supports  12 ,  12   a . A ramp  20  can be seen to be releasably engaged the forward wheel support  12  such that a vehicle can be driven up the ramp  20  and over the bridge section  30  such that two of the vehicles wheels are supported on the wheel supports  12 ,  12   a.    
     As discussed above, the structures can be simply duplicated to provide four wheel supports  12 ,  12   a  positioned in spaced apart relation corresponding to the spacing of the wheels of the vehicle to be supported thereon. Two bridge sections  30  extend between two of the wheel supports  12  positioned at the front and two of the wheel supports  12   a  positioned at the rear such that the bridge sections  30  have an upper surface  32  that is substantially level with the top support surfaces  14  of the wheel supports  12 ,  12   a . At least two ramps  20  are releasably engaged with either the two forward  12  or rear  12   a  wheel supports such that a car can be driven up the ramps  20  and over the bridge sections  30  such that the four vehicle wheels are supported on the four wheel supports  12 ,  12   a.    
     Additionally, the rear wheel supports  12   a  can be seen to include a second engaging surface  24  on a rear surfaces  26  thereof. This second engaging surface  24  is formed to be modular and of the same size and configuration as the first engaging surface  16  at the front of the front wheel supports  12 . In these figures the rear engaging surface  24  can be seen to receive and retain a wheel stop  28 . The wheel stop  28  is provided to prevent a vehicle wheel positioned on the support surface  14  from rolling too far forward such that it rolls completely off of the support surface  14 . Additionally, however, the wheel stop  28  can be removed and the ramp  20  can be repositioned to allow the vehicle to be taken down from the support surface  14  by continuing in a forward direction as desired by the user. It is of further note that the bridge sections  30  and ramps  20  can be selectively removed once the vehicle is positioned on said wheel supports  12 ,  12   a . This allows a user to more easily access the underside of the vehicle. 
     It can also be seen that the wheel supports  12 ,  12   a  may be formed to include recesses  34  in the top support surfaces  14  thereof. Such recesses  34  may be included to allow additional accessories such as scales  36 , turntables or slip plate stands to be positioned on the support surfaces  14  thereby allowing a vehicle positioned thereon to be weighed or aligned. When scales  36  are not provided in the recesses  34 , a cap may be placed into the recess  34  to create a smooth flush top support surface  14 . 
       FIGS. 5 and 6  also depict that the bridge sections  30  are adjustable in length. Such length adjustment may be accomplished by any modular means known in the art. In this case the bridge  30  is shown to simply employ shim  38  components and a modular bridge extension member  40  to increase the length thereof. This allows the modular ramp system to be employed with vehicles having a wide range of wheelbase dimensions. 
     In each of the embodiments, all of the components described above are monolithically constructed using a lightweight composite comprised of an expanded foam plastic core, in particular, a expanded polystyrene foam which is encapsulated in a high tensile strength polyurea coating of sufficient thickness to provide a durable surface when cured and create a strong composite structure. The polyurea coating is preferably applied by spraying liquid components onto the foam plastic core so as to create a textured surface for good tire traction. The polyurea coating may optionally be top coated with a hard coat of an abrasion and water resistant color stable polyurea formulation. The combination of the core and high tensile strength polyurea coating creates a sufficiently strong and durable structure to be very well suited for use as a vehicle service ramp. 
     As stated above, the components of the ramp system are preferably formed using an expanded polystyrene foam (EPS) of a density on the order of 1.5 to 6 pounds per cubic foot. The heavier densities of 5 or 6 pounds per cubic foot can be used for heavy-duty ramps. The core  12  is encased within a polyurea coating  28  which is preferably sprayed on so as to create a coating having a textured finished surface to enhance tire traction. This polyurea coating which is sprayed onto the core is formulated and of sufficient thickness to develop adequate tensile strength so that the ramp  10  may accommodate the weight of passenger cars. Polyurea may be formulated in a number of ways. A suitable type of polyurea is F1-2546 POLY available from VOLATILE FREE, INC. of Brookfield, Wis. 53045. The thickness of the polyurea coating will typically be on the order of 35-65 mils of this material. It will provide adequate tensile strength for most applications. Even thinner coatings may be adequate, as a tensile strength of 2500 psi is obtained with a 25-mil thickness of 58 (Shore D) hardness suitable for light duty applications. Additionally, a topcoat may be applied such as Polyshield HM-7030 available from Specialty Products, Inc. that has a high degree of water resistance. In addition to the construction described above, the present invention may also be implemented using other lightweight laminates such as fiberglass, carbon fiber composites and composite nanomaterials. Further, each of the above may also include core supports in the form of wood and/or metal panels and/or bulkheads. 
     This construction allows a wide variety of ramp configurations, even custom ordered configurations, to be made very economically with minimal tooling costs. Any configuration of core  12  can be simply cut out of EPS foam by standard cutting tools and then spray coated with polyurea to a suitable coating thickness. Further, the solid bottom of the ramp system components insures good stability and much reduced tendency to sink into soft surfaces. The absence of any nooks or crannies and the hard polyurea coating makes keeping the ramps clean easy. 
     For heavier duty designs, additional strengthening features can be employed to resist compressive loads. This may include one or more panels of plywood or other sturdy material such as plastic or metal, oriented on edge or layed flat within the core, braced by the presence of the expanded polystyrene foam of the core encasing the panels. These panels brace the ramp components to greatly enhance the overall compressive strength of the ramp. In a similar fashion, other internal structures can be used, such as molded plastic shapes. However, it has been found in reinforced ramps made by the above described method are of adequate strength for many automobiles as vehicles up to 6000 pounds gross weight may be safely supported. 
     It can therefore be seen that the present invention provides a modular ramp construction that can be reconfigured with the vehicle in place thereon to allow easier access to the underside of the vehicle. It can be further seen that the present invention provides a lightweight but durable and stable modular ramp that is useable on softer surfaces and which can easily be rearranged into many different configurations. For these reasons, the instant invention is believed to represent a significant advancement in the art, which has substantial commercial merit. 
     While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.