Abstract:
An undercarriage skid plate consisting of a structural frame, heavy-duty rollers, mounting brackets, quick disconnect attachment means, and impact isolation mounts, primarily for use on off-road vehicles. The roller skid plate frame houses an array of heavy duty rollers with axes of rotation the same as the wheels of the vehicle. Mounting brackets are directly attached to the vehicle frame with appropriate fasteners. The skid plate frame is secured to the brackets with quick-disconnect fasteners inserted through impact absorbing bushings. The roller skid plate provides protection to vehicle undercarriage components while also reducing the amount of frictional drag generated when a vehicle encounters an off-road hazard. The quick disconnect mounts allow for easy removal of the skid plate for such purposes as to service the vehicle. The isolation mounts reduce the force conducted through vehicle&#39;s frame when impact with an off-road hazard is made.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]      
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
               
             
             
               
                 1,182,378 
                 A 
                 May 1916 
                 Jewell 
                 180/69.1 
               
               
                 3,137,466 
                 A 
                 May 1962 
                 Warren 
                 248/9 
               
               
                 3,508,745 
                 A 
                 May 1970 
                 Deane 
                 267/57.1 
               
               
                 3,779,330 
                 A 
                 December 1973 
                 Longpre 
                 180/69.1 
               
               
                 3,825,284 
                 A 
                 July 1974 
                 Behrle 
                 280/515 
               
               
                 3,826,327 
                 A 
                 July 1974 
                 Stover 
                 180/69.1 
               
               
                 3,865,407 
                 A 
                 February 1975 
                 Klassen 
                 280/515 
               
               
                 4,099,739 
                 A 
                 July 1978 
                 Foley 
                 280/504 
               
               
                 4,114,717 
                 A 
                 September 1978 
                 Andrews 
                 180/69.1 
               
               
                 4,298,212 
                 A 
                 November 1981 
                 Jamison 
                 280/515 
               
               
                 4,407,381 
                 A 
                 October 1983 
                 Oswald 
                 180/6.48 
               
               
                 4,655,307 
                 A 
                 April 1987 
                 Lamoureux 
                 180/69.1 
               
               
                 5,992,926 
                 A 
                 November 1999 
                 Christofaro et al. 
                 296/204 
               
               
                 6,193,260 
                 B1 
                 February 2001 
                 Haman et al. 
                 280/515 
               
               
                 6,202,778 
                 B1 
                 March 2001 
                 Mistry et al. 
                 180/69.1 
               
               
                 6,206,407 
                 B1 
                 December 1998 
                 Fuchs et al. 
                 280/68.6 
               
               
                 6,516,907 
                 B2 
                 February 2003 
                 Robinson 
                 180/69.1 
               
               
                 6,726,273 
                 B2 
                 April 2004 
                 Kruschhausen et al. 
                 296/204 
               
               
                 7,055,895 
                 B1 
                 June 2006 
                 King et al. 
                 296/204 
               
               
                   
               
             
          
         
       
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0003]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    This invention is an innovation to land vehicle skid plates, specifically for off-road motor powered land vehicles. This invention relates to protection devices typically mounted to the undercarriage of motorized land vehicles, with the purpose to protect vulnerable components such as the engine, oil pan, transmission, transfer case, and the like from damage caused by impact with an off-road hazard or obstacle. 
         [0006]    2. Description of Related Art 
         [0007]    Motorized land vehicles, specifically of the off-road variety, have employed the use of skid plates to protect vulnerable undercarriage components from damage. Skid plates known in the art are typically constructed of plates of steel, aluminum, or other metal alloys, which cover the area of the vulnerable component and are rigidly mounted to the frame or unit body structure of the vehicle. 
         [0008]    Due to the construction of the known skid plates, with typically flat sheets of metal, the coefficient of friction between the known skid plate and any trail hazard or obstacle is large. Due to the rigid mounting of the known skid plate to the frame of the vehicle, a large portion of the weight of the vehicle will be transferred to the contact point between the known skid plate and the trail hazard. This large portion of vehicle weight combined with the high coefficient of friction can create enough drag to impede the intended motion of the motorized land vehicle. The force required to overcome this drag force and move the vehicle in the intended direction can easily be greater than the available torque between the tires of the vehicle and the ground, resulting in tire slippage, potentially resulting in damage to the motorized land vehicle and the trail. 
         [0009]    The mounting means of attaching the known skid plates to a vehicle is typically accomplished through rigid mounting means. This method of attachment provides no means of impact absorption, thereby transmitting the entire force of impact through the skid plate to the vehicle. Transmittal of this impact force can be severe enough to cause damage to the vehicle for which the skid plate is designed to protect. This complete transfer of impact force to the vehicle can be jarring and undesirable to the occupants of the vehicle. One known exception to rigid mounting of the known skid plate is cited in U.S. Pat. No. 6,516,907 Engine Mounted Skid Plates, in which the known skid plate is directly mounted to an engine or transmission of a vehicle thereby utilizing the energy absorption characteristics of the engine or transmission mounts. While this may accomplish the reduction of impact force transmitted to the vehicle, it may also over tax the integrity of the engine or transmission mounts whose primary function and design is to provide vibration isolation, support of the engine or transmission, and on some new vehicles to collapse or break away in the event of a collision, not to withstand repeated impacts with immoveable objects. 
         [0010]    Moreover, the design and rigid mounting of known skid plates restricts access to undercarriage components which may need routine maintenance or repair. Removal of the entire known skid plate may be necessary to gain the access needed for the maintenance. Removal of the known skid plate is often cumbersome, requiring additional tools and adding labor time to perform the maintenance. 
         [0011]    Therefore, there is opportunity for innovation in the art for a skid plate which has a means to reduce the coefficient of drag when in contact with a hazard or obstacle, provides for some impact absorption, and facilitates easy access to the undercarriage components of the vehicle for maintenance purposes. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention is directed toward a skid plate having a plurality of rollers to facilitate the motion of a land vehicle during encounters between said skid plate and trail hazards, obstacles, and other immovable objects. The skid plate may have a rigid frame which houses the rollers and provides structural integrity for the skid plate. The frame may also provide housing for polymer based impact absorbing bushings to be used in mounting of the skid plate. The present invention is further directed toward a skid plate possessing mounting brackets which incorporate a quick disconnect mechanism to facilitate the removal and installation of the skid plate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of the complete assembly of the preferred embodiment of the present invention; 
           [0014]      FIG. 2  is a perspective view of only the structural rigid frame and isolation mounts of the preferred embodiment of the present invention; 
           [0015]      FIG. 3  is an exploded view of the components comprising the roller assembly of the preferred embodiment of the present invention; 
           [0016]      FIG. 4  is a perspective view of a side mounting bracket used in the preferred embodiment of the present invention; 
           [0017]      FIG. 5  is a perspective view of a rear mounting bracket used in the preferred embodiment of the present invention; 
           [0018]      FIG. 6  is an exploded view of the components comprising the quick release mechanism used in the preferred embodiment of the present invention; 
           [0019]      FIG. 7  is an exploded view of the components comprising the isolation mounts used in the preferred embodiment of the present invention; 
           [0020]      FIG. 8  is a side elevation view of the preferred embodiment of the present invention mounted in a typical configuration to a motorized land vehicle. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    This detailed description conveys the best mode contemplated for carrying out the present invention. The intention of this description is not to project exclusivity of the mode described herein, and as such mention of possible deviations, permutations, and modifications foreseen in the execution of the present invention will additionally be mentioned. 
         [0022]    Referring to  FIG. 1 , the roller skid plate assembly  10  is composed of a rigid frame  12  for housing the plurality of rollers  20 . This embodiment of the present invention includes seven rollers  20 . The actual number of rollers  20  may vary depending on the size of the vehicle, the component which the skid plate  10  is protecting, and other vehicle features which may warrant a quantity of rollers  20  more or less than seven. As seen in  FIG. 8 , the roller skid plate  10  is connected to the frame  101  or unit body structure of the land vehicle via mounting brackets. This embodiment of the present invention references two side mounting brackets  30  and one rear mounting bracket  40 . The location and quantity of the mounting brackets may vary in accordance with vehicle dimensions and availability of mounting locations. 
         [0023]      FIG. 2  depicts the typical rigid frame  12 . The rigid frame  12  may be constructed of steel, aluminum, or other metal alloy members with sufficient strength of materials to provide protection from all foreseen impacts which the present invention may encounter in use as an off-road vehicle skid plate. Furthermore the material used for the rigid frame  12  must possess characteristics which enable the rigid frame  12  to withstand other hazards including but not limited to extreme heat, extreme cold, contact with chemicals, and contact with hard objects encountered in use as an off-road vehicle skid plate. The rigid frame may have two side members  14  which are oriented parallel to the left and right side of the vehicle. Attached between and perpendicular to the two side members  14  may be a front member  15 , a rear member  16 , and a center member  17 . The preferred method of connecting the members to form the rigid frame  12  is welding; however removable fasteners, metal forming, or other bonding methodologies may also be used. A slot  13 , hole, or cut-out may be formed in the center member  17  to facilitate access to a drain plug or other vehicle component which may require frequent access. The two side members  14  of the rigid frame may contain a plurality of holes  19  to provide means for locating and supporting of the rollers  20 . The holes  19  on each side member  12  must be directly opposite holes on the opposing side member  12  and situated in such a way as to provide the axes of rotation of the rollers  20  are parallel to the axes of rotation of the wheels  102  of the vehicle. Attached to the rigid frame  12  are bushing housings  18 . The bushing housings  18  may be attached to the rigid frame  12  by means of welding. Positioning of the bushing housings  18  may depend on vehicle geometry and location of convenient mounting locations on frame  101  of the vehicle. 
         [0024]    This present invention includes rollers  20  which may be constructed of a length of DOM (Drawn Over Mandrel) tubing  22  which may be cut to the appropriate length for the size of the rigid frame  12 . The outside diameter in combination with the inside diameter of the tubing  22  should be in such proportion as to provide sufficient strength to withstand impacts with road hazards whilst minimizing the loss of ground clearance of the vehicle to which the roller skid plate  10  is attached. As seen in  FIG. 3 , located at both ends of the length of DOM tubing  22  are bushings  26  which are inserted into the length of DOM tubing  22  and may be retained by a friction fit. The roller bushings  26  may be made of a high strength polymer material which exhibits low coefficient of friction. Each bushing  26  has a concentric through hole in which the axle rod  24  passes through. Those skilled in the art will understand the workings of an axle rod and roller. In this present invention the axle rod  24  extends beyond the outside edge of both rigid frame  12  side members  14 . A cotter pin  28  may be used at each end of the axle rod  24  as a retention device to prevent the axle rod  24  from sliding through either side members  14  of the rigid frame  12 . Other commonly available retention means may be employed, such as c-clips, axle nuts, or threaded fasteners. 
         [0025]    The two side mounting brackets  30  used in this present invention can be seen with more detail in  FIG. 4 . The side brackets serve the function of attaching the rigid frame  12  of the present invention to the frame  101  or unit body structure of the vehicle. One end of the bracket is rigidly and removably attached to the vehicle whilst the other end is attached to the rigid frame  12 . The end of the side mounting bracket  30  which attaches to the vehicle may be constructed of steel angle iron  32  or other structural steel profiles. The angle iron  32  segment may have holes  34  to facilitate the use of threaded fasteners as means of attachment to the vehicle. The center segment  36  of the side mounting bracket  30  may be constructed of square tube or other structural steel profiles. The length of the center segment  36  is dependent on the distance between the location of mounting to the vehicle and the side member  14  of the rigid frame  12 . The center segment  36  may incorporate some bends or twists to accommodate clearance around vehicle components such as drive-shafts, exhaust pipes, and the like. The other end of the side mounting bracket  30  provides the means for attachment to the rigid frame  12 . This end may be constructed of flat steel welded together to form a U-shaped member  38 . The U-shaped member  38  has two opposing holes  39  to allow for the quick release pin  52  to be extended through the side mounting bracket  30 . All three segments of the side mounting bracket  30  may be welded together, forming one solid bracket. 
         [0026]    The present invention includes one rear mounting bracket  40 , as seen in  FIG. 5 , used to secure the rigid frame  12  to a structural cross member of the frame  101  or a factory installed transfer case skid plate  103  of the vehicle. The rear mounting bracket  40  is similar in construction to the side mounting brackets  30  and serves the same function. The rear mounting bracket  40  may be constructed of a flat steel base member  42  welded to an upright forward facing flat steel member  44 . The upright forward facing member  44  is useful to stiffen the rear mounting bracket  40  and to provide a surface for attaching the cantilevered mounting arms  46 . Holes  47  in the cantilever arms  46  may be used for assembly to the rigid frame  12  by means of the quick release pin  52 . Welding may be the preferred method of attaching the cantilevered mounting arms  46  to the rear mounting bracket  40 . Metal forming with a brake press is another method of fabrication which may be employed in the construction of the rear mounting bracket  40  without deviating from the intent of the present invention. Holes  48  in the flat base member  42  may be used to provide means for rigidly and removable mounting the rear mounting bracket  40  to a cross member or transfer case skid plate  103  of the vehicle. 
         [0027]    Referring to  FIG. 6  and  FIG. 7 , it can be seen the means of connecting the side mounting brackets  30  and the rear mounting bracket  40  to the rigid frame  12  employs the use of an assembly consisting of a hitch pin  52 , a hair clip pin  54 , two isolation bushing halves  56  and a cylindrical sleeve  58 . The two bushing halves  56  are inserted into opposing ends of the bushing housing  18  on the rigid frame  12 , until the shoulder of the bushings  56  seat against the ends of the bushing housing  18 . The cylindrical sleeve  58  is inserted through the center of the two bushing halves  56  with a tight friction fit and resulting with both ends of the cylindrical sleeve  58  approximately being flush with the outside ends of each bushing half  56 . Those skilled in the art will realize this arrangement is very similar to the arrangement of a typical leaf spring bushing found in many motorized land vehicles. The bushing halves  56  may be made of a rubber or polyurethane compound which will provide impact absorption during encounters between the roller skid plate  10  and road hazards. 
         [0028]    In field application of the present invention, the preferred method of assembly would be to removably attach both side mounting brackets  30  and rear mounting bracket  40  to the land vehicle frame  101 , unit body structure, cross member, or transfer case skid plate, using high strength threaded fasteners. The next step would be connecting of the rigid frame  12  to either the side mounting brackets  30  or the rear mounting bracket  40  which may be accomplished using the quick release pins  52  and clips  54 . The roller skid plate  10  rigid frame  12  is positioned such that the center of the bushing halves  56  in the bushing housing  18  are aligned to the holes  39  in the side mounting bracket or the holes  47  in the rear mounting bracket, the quick release pin  52  is then inserted through one of the holes  39  or  47  and continuing through the cylindrical sleeve  58  and finishing through the opposing hole  39  or  47 . A hair clip type pin  54  is then inserted in the hole  55  found at the end of the quick release pin  52  to prevent the quick release pin  52  from accidental removal. The preferred sequence of attachment in the present invention would be to connect the rear mounting bracket  40  first, followed by one and then the other side mounting bracket  30 . Removal of the rigid frame  12  for the purpose of gaining access to vehicle components for repair or maintenance, or to just remove the rigid frame  12  from the vehicle is accomplished by reversing the order of attachment outlined above. 
         [0029]      FIG. 8  depicts the roller skid plate  10  in a typical configuration mounted to a motorized land vehicle. In this configuration the roller skid plate  10  is providing protection to the engine  104  and a portion of the transmission  105 . The transfer case  106  is protected by a factory installed skid plate  103 , to which the rear mounting bracket  40  is removably attached.