Abstract:
The invention is a tow bar adapter which is attached to the existing fittings of the commonly used tow bar used to tow a vehicle behind a motor coach and selectively elevate the front end of the towed vehicle. The invention is a also a method for providing a tow bar adapter attached to the existing fittings of a standard tow bar used to tow a vehicle behind a motor coach and selectively elevate the front end of the towed vehicle.

Description:
FIELD OF THE INVENTION 
   The invention pertains to the towing of vehicles, and is designed to permit backing of a motor coach that is towing a four-wheeled steerable vehicle. 
   BACKGROUND OF INVENTION 
   Cars and light trucks are commonly towed behind motor homes for the purpose of providing local transportation after the motor home is attached to the campground facilities. Commonly used tow bars restrict a driver&#39;s ability to back the motor home and car combination while the tow bar is fitted to the towed vehicle. If backing is attempted, the front wheels often twist or turn, thereby preventing straight backing. 
   There are newer tow bars available which allow backing, but are limited to certain tow vehicles with specific front wheel caster angles. The present invention is not so limited. Instead, the invention, when used properly, reduces problems associated with jackknifing or cramping of steer wheels of varied towed vehicles. 
   SUMMARY OF THE INVENTION 
   The Inventive Adapter 
   The invention is an adapter configured to assist a driver in backing a motor home having a towed vehicle behind it. The invention is also a method for accomplishing the same. 
   The inventive adapter is configured to fit to standard attachments used in the towing of a vehicle behind a motor home. Generally, the standard attachment is a common three-point towbar with horn-like tabs. The tabs protrude from a front face of the vehicle. Further, the motor coach has, at its rear, standard fittings that receive a three-point towbar. Specifically, the adapter will include a bracket including a plate with receptacles attached to the bracket. Each receptacle is configured to receive a respective horn-like tab that protrude from the front face of the vehicle. 
   The adapter will also have a means for securing the adapter in a locked position, wherein the respective tabs are secured within the receptacles. The adapter will also include an elevator configured to selectively position the adapter, thereby raising a front end of the towed vehicle, enabling a driver to more easily back the tandem of the coach and towed vehicle. 
   In a preferred embodiment, the elevator is a jack, such as a scissors jack, screw-type jack, an electric scissors jack, an electric jack, or the like. The plate may have an aperture allowing the post to pass through. In this embodiment, collars couple the post (which usually bears a telescoping configuration) to the plate. 
   In order to increase sturdiness and stability, a web support may extend generally upward and orthogonal from the plate. This web support may terminate in an upper plate having a bore positioned above the aperture. In this embodiment of the adapter, the elevator is a jack having a post that passes through the bore and the aperture. 
   The adapter will likely include a switch configured to selectively activate the elevator. Preferably, the switch that selectively activates the elevator is located distal the adapter, preferably within the motor home. 
   A wheel, roller or skid is positioned at the bottom end of the post. When the motor coach is driven forward, the adapter is kept in a position elevated from the ground. When the driver desires to back the motor coach, however, the elevator is activated to further raise the front end of the towed vehicle, preferably off the ground. Alternatively, the elevator may raise the front end of the vehicle so that the front wheels lightly touch the ground with minimal weight, which of course reduces the friction and resistance between the wheels and the ground. In this raised position, the towed vehicle behaves much like a two-wheeled trailer, thereby eliminating the problems encountered with towing a four-wheeled vehicle behind a backing motor home. 
   A wheel, skid, or other ground engaging means is at the terminal end of the lower post. It is important that the adapter be constructed of material that is strong, sturdy, and weather resistant. Cast iron and other rust-proofed metals having substantial strength are preferred. 
   The Inventive Method 
   As stated above, the invention also includes a method. The inventive method is for backing up a motor coach having a towed vehicle attached thereto. The towed vehicle is attached to the motor home by means of a common three-point towbar, and the vehicle has standard horn-like tabs protruding from its front face or may have internal receivers to which a horn-like tab is attached. More particularly, the method will include the steps of providing an adapter as described herein, and securing the adapter in a locked position, such that the respective tabs are positioned within the respective receptacles. The inventive method will also include the step of positioning the adapter between the vehicle and the motor coach, and coupling the adapter to each of the vehicle and the motor coach. 
   The method will also require the attaching of an elevator to the adapter. This elevator should be configured to selectively position the adapter between a first position, wherein the front wheels of the towed vehicle touch the ground, and a second position wherein the front of the towed vehicle is elevated, preferably disengaging the front wheels from the ground. When the front wheels are off the ground, the driver can back the motor coach with greater ease. 
   Optionally, the elevator may be a jack, such as an electric scissors jack, an electric screw-type jack, a power jack, or the like. In an alternate embodiment of the method, the plate bears an aperture, and the jack has a post that passes through the aperture. Generally, it is preferred to have a single elevator, but multiple elevators are within the scope and spirit of the invention. Stability of the adapter may be increased by adding a web support that extends generally upward from the plate. In this embodiment of the method, these web supports may terminate in an upper plate having bore positioned above the aperture. Consequently, the elevator is a jack having a post that passes through each of the bore and the aperture. 
   The method may also include the step of configuring a switch to selectively position the adapter in either the raised or lowered position. The switch may be positioned in a remote location distal the adapter, such as within the motor home. The elevator may be battery powered, such as powered by the battery of the towed vehicle, or even powered by a battery within the motor home. In that regard, the method will include the step of electrically connecting the elevator to the battery. Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view showing the inventive adapter and method, shown with the adapter in a raised position and the vehicles traveling forward. 
       FIG. 2  is a comparative side view of the inventive adapter and method, shown with the adapter in a ground-engaging position and the vehicles traveling backward. 
       FIG. 3  is a plan view of the top portion of the bracket portion of the adapter, according to the principles of the invention. 
       FIG. 4  is a perspective view showing a first preferred embodiment of the adapter and its bracket, according to the principles of the invention 
       FIG. 5  is a perspective view showing a second preferred embodiment of the adapter and its bracket, according to the principles of the invention. 
       FIG. 6  is a perspective view of the first embodiment of the adapter coupling the rear of a motor home to the front of a towed vehicle, according to the principles of the invention. 
       FIG. 7  is a perspective view of the second embodiment of the adapter coupling the rear of a motor home to the front of a towed vehicle, according to the principles of the invention. 
       FIG. 8  is an isolated, perspective view showing the first embodiment of the adapter coupled to the front end of a towed vehicle. 
       FIG. 9  is an isolated, perspective view showing the second embodiment of the adapter coupled to the front end of a towed vehicle. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  depicts he inventive adapter  10  and method, shown with the adapter  10  in a raised position and the vehicles  22 ,  24  traveling forward. When traveling forward, the adapter  10  is in a raised position so that it does not engage the ground. The adapter  10  comprises a bracket  18  positioned between an upper post  16  and a lower post  14  having a wheel  48  coupled to its bottom end. 
   As shown in  FIG. 1 , the adapter  10  is coupled to the front end  16  of the towed vehicle  24 , and also connects to a tow bar  20  connected to the coach  22 . Preferably, the wheel  48  is sufficiently elevated to provide ground clearance and prevent unwanted contact with the ground when the vehicles  22 ,  24  are traveling forward. 
     FIG. 2  shows a comparative side view of the adapter  10  when activated to raise the front end  26  of the vehicle  24  from the ground. By activating an elevator control  12 , the lower post  14  telescopes downwardly so that the wheel  48  engages the ground. Further, the lower post  14  should continue to telescope downwardly in order to elevate the front end  26  from the ground, thereby easing the difficult task of traveling backward. 
   Still referring to  FIG. 2 , it is of note that the front wheel  28  is shown to be lifted off the ground. Through experimentation and use, it has been determined that the front wheel  28  need not completely disengage the ground. Rather, raising the front end  26  of the vehicle  24  so that the front wheel  28  remains in light contact with the ground will produce positive results as well, because the frictional resistance caused by the weight of the front end acting on the ground through the front wheels is greatly reduced. 
     FIG. 3  is a plan view of the bracket  18  of the adapter  10 , according to the principles of the invention. The bracket includes a sturdy plate  32  having an aperture  40  configured to accommodate the lower post  14  (not shown in  FIG. 3  but viewable in  FIG. 1 ). A pair of receptacles  30  extend from the bracket  18  and are configured to receive horn-like posts that protrude from the front end of a towed vehicle. 
   Still referring to  FIG. 3 , the bracket  18  will also include an upper plate  36  having a bore  36  formed to receive the upper post  16  (not shown in  FIG. 3  but viewable in  FIG. 1 ). The upper plate  36  is connected to the lower plate  32  by supporting webs  33  that extend upwardly from the lower plate  32 . A pair of couplers  38  extended outwardly from the bracket  18  and are configured to engage a tow bar  20  that couples the vehicles  22 ,  24  together. 
     FIG. 4  is a perspective and exploded view showing the bracket  18  in combination with a skid  42  that is coupled to the bottom end of the lower post  14 . One should note that the configuration of the bracket  18  is similar for either the first (shown in  FIG. 4 ) or second (shown aft) embodiments of the adapter  10 , so the analogous and similar parts of the bracket  18  are not repeated with regard to the description set forth regarding  FIG. 4 . 
   The embodiment shown in  FIG. 4  shows a skid  42  coupled to the bottom end of the lower post  14 . The lower post  14  is coupled directly to a slab  46 , and the skid  42  is firmly coupled to the slab  46 . A pair of scissors jacks  44  are positioned on opposing sides of the lower post  14 , and connect the slab  46  to the lower plate  32  of the bracket  18 . 
   The embodiment shown in  FIG. 4  is preferred when backing on rough or uneven or unpaved surfaces, such as gravel, dirt, or grass. The skid  42  is generally formed of a durable and sturdy material (such as a polyester or hard plastic) that is slightly pliable and provides some damping of the vibrational impact caused by engaging the ground while the vehicles  22 ,  24  are moving. 
   Still referring to  FIG. 4 , other ground-engaging means fall within the scope of the invention; for example, a plurality of wheels or rollers may be positioned on the underside of the slab  46 , giving the adapter  18  sturdy support. 
     FIG. 5  depicts a second preferred embodiment of the adapter and its bracket, according to the principles of the invention. Because many of the parts of the second embodiment of the adapter  18  are analogous to the first embodiment shown in  FIG. 4 , a detailed discussion of these analogous parts would be unnecessary and repetitive. Note, however, that the second embodiment differs from the embodiment shown in  FIG. 4  in that the ground-engaging portion of the bracket  18  differs significantly. The lower portion of the post  14  (preferably telescoping, perhaps into upper post  14 ), terminates with a wheel  48  (such as a caster wheel or roller) coupled to its bottom end. 
   If one opts to use the embodiment shown in  FIG. 5 , it is important that the wheel  48  be sufficiently sturdy to accommodate the weight of the towed vehicle, the frictional force created by engagement with the ground, and any impacting forces created by movement along an unsteady surface. In order to increase stability, a plurality of wheels or rollers may be positioned at the bottom of the lower post  14 . In order to minimize impact, the adapter  18  may include a damper  49 . As shown in  FIG. 5 , the damper  49  is a sturdy yet pliable collar between the wheel  48  and the bottom of the post  14 . 
     FIG. 6  shows the adapter  10  connecting the front end  26  of a towed vehicle  24  to the rear of a motor coach  22 . A tow bar  20  extends from the rear of the motor coach and connects to couplers  38  that extend from the bracket  18 . A pair of receptacles  30  extend from the bracket  18  to lockingly engage horn-like tabs that protrude from the front end  24  of the vehicle, such as through its grille. 
   Still referring to  FIG. 6 , the lower post  14  extends downwardly from the bracket  18  and terminates by coupling with slab  46 . A skid  46 , preferably of a durable yet pliable material, attaches to the slab and forms a smooth ground-engaging surface. 
   As shown in  FIG. 6 , a scissors jack  44  engages the slab  46  at one of its ends, and the bottom of the bracket  18  at its other end. As shown above, it is preferred to use a pair of scissors jacks  44 , each of the pair being positioned at an opposing side of the lower post  14 . 
   As shown in  FIG. 6 , the adapter  10  will include an elevator control  12  including a switch  13  that can selectively activate the elevating means (such as scissors jack  44 ), causing the lower post  14  to telescopically expand downwardly so that the skid  42  engages the ground, thereby imparting a lifting force to the front end  26  of the towed vehicle. 
   As the front end  26  of the towed vehicle  24  is elevated, the tow bar  20  will accordingly raise as well, thereby imparting a counter-clockwise rotation (given the orientation shown in  FIG. 6 ) of the end distal the coach  22  with regard to the end attached to the hitch of the coach. While many standard tow bars are configured to allow some relative rotation, it is important to cooperatively configure the tow bar  20  with the couplers  38  in order to accommodate some relative rotation yet meanwhile provide a secure connection. 
   The embodiment shown in  FIG. 6  features an elevator control  12  enabling selective activation of the elevating means (such as scissors jack  44 ). Alternatively, the elevator control  12  may be selectively activated by a remote control device  11  enabling activation of the elevator control from a remote location, such as from within the motor coach  22 . The elevator control  12  may be powered by an internal battery pack (not shown) or connected via cables  50  to the battery of the towed vehicle  24 . 
     FIG. 7  shows the a second embodiment of the adapter  10  connecting the front end  26  of a towed vehicle  24  to the rear of a motor coach  22 . The parts of the embodiment of the adapter  10  shown in  FIG. 7  are in many ways, similar and analogous to the parts shown in  FIG. 6 , except that the ground engaging skid is replaced by a wheel  48  positioned at a bottom end of the lower post  14 .  FIG. 7  shows a single wheel  48  positioned at the bottom of the lower post  14 ; however, additional wheels may be added to increase stability and durability. 
   Experimentation and use have shown that the embodiment shown in  FIG. 7  is well-suited for paved or smooth surfaces; rough and unpaved surfaces may cause a single wheel  48  to jam, so it is important to select a wheel (or plurality of wheels) capable of supporting dynamic loads. 
     FIG. 8  is an isolated, perspective view showing the first embodiment of the apter coupled to the front end of a towed vehicle. As with previous views, the parts of the adapter  10  shown in  FIG. 8  are analogous and similar to views hereinabove. The telescoping lower post  14  attaches to slab  46 , which is connected to a pliable yet sturdy skid  42 . A pair of scissors jacks  44  are on opposing sides of the lower post  14  so that the bottom of each is affixed to the slab  46  and the top is affixed to the bracket  18 . The scissors jacks  44  may be selectively activated by means of the elevator control  12 . 
   Still referring to  FIG. 8 , the scissors jacks (or other elevating means)  44  are selectively activated by the elevator control  12 , which may bear a switch enabling are selective activation of the elevator control  12 . The elevator control  12  is empowered electronically, either by a self contained battery pack or using cables  50  to connect the elevator control  12  to the battery of the towed vehicle  24 . 
   As shown in  FIG. 8 , a pair of couplers  38  extend from the bracket  18  and are configured to grip cooperatively configured receptacles of a tow bar  20  (not shown in  FIG. 8 ; viewable in  FIGS. 1 ,  2 ) 
     FIG. 9  is an isolated, perspective view showing a second embodiment of the adapter  10  coupled to the front end  26  of a towed vehicle  24 . In many ways, the parts of the embodiment shown in  FIG. 9  are analogous and similar to the parts of the embodiment shown in  FIG. 8 . For example, a bracket  18  is secured to horn-like tabs protruding from the front end  26  of a towed vehicle  24 ; further, an elevator control  12  is positioned atop an upper post  16 , and is secured to the bracket  18 . Moreover, like previously shown embodiments, a telescoping lower post  14  terminates in a ground-engaging means, such as a wheel  48 , and couplers  38  extend outwardly from the bracket  18  and are configured to securely attach to a tow bar  20 . 
   Experimentation and use have shown that the embodiment shown in  FIG. 9  is better suited for paved or smooth surfaces, as the bumps and divots of an uneven surface or soft earth (such as grass, dirt, or gravel roads) may expose the wheel  48  to excessive damaging vibration, or may cause the wheel  48  to sink into soft ground, causing it to jam. In that regard, a damper  49  of resilient material may be positioned between the end of the lower post  14  and the wheel  48 . 
   Although the present invention has been described and illustrated in detail, and a specific example has been given, these are for illustration and example only, and are not taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.