Abstract:
An adjustable trailer hitch which provides an operator improved remote control of the lateral position of a trailer hitch, and simplifies the procedure of hooking a trailer to a tow vehicle. The trailer hitch comprises a hitch assembly (such as a ball receptacle) attached to a roller carriage which moves from side-to-side along a bumper-like housing. The roller carriage engages a positioning screw, and an electric motor mounted in a sealed end cap powers the positioning screw. Rotation of the screw translates into rightward or leftward lateral movement of the roller carriage and consequently of the ball receptacle assembly. Motion of the ball receptacle assembly is controlled via a wireless remote control unit. Such direct control over the precise lateral position of the trailer hitch enables the operator to accurately steer the trailer when traveling in reverse. During hook-up, lateral movement of the hitch enables the operator to connect the trailer and the tow vehicle from a greater range of positions, and eliminates the need for absolute accuracy of alignment between the tongue of the trailer and the hitch of the tow vehicle as required by traditional fixed hitches.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application derives priority from U.S. provisional application Nos. 60/251,187 for REMOTE CONTROL TOWING-HITCH ASSEMBLY”; Filed: Dec. 5, 2000, and 60/262,348 for REMOTE CONTROL TOWING-HITCH ASSEMBLY AND ATTACHMENT DEVICE”; Filed: Jan. 18, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to trailer hitches and, more particularly, to an articulating trailer hitch with remote control mechanism to allow the user to compensate for misalignment of the hitch and trailer tongue during hook-up. 
     2. Description of the Background 
     There has been a sharp increase in driver preference for sport utility vehicles and pick-up trucks over the past decade, and this is partly due an increased demand for more powerful towing capabilities. Such tow vehicles are commonly used to pull trailers for boats, other cars, water-craft, landscaping and lawn-care machinery, livestock, as well as campers, moving trailers, and general purpose trailers. The general increase in towing has sensitized consumers to the hardships which arise from the use of a traditional fixed trailer hitches. 
     There is often great difficulty in hooking a trailer to a tow vehicle equipped with a fixed tow hitch because the tow vehicle and the trailer must be precisely aligned to make the proper connection. The difficulty is exacerbated by the fact that the view of the trailer hitch and trailer tongue are usually obscured from the driver&#39;s view by the rear of the vehicle. Therefore, hook-up is often a two-person operation, carried out with the first person operating the vehicle and the second person, positioned at the rear of the vehicle with a clear view of the hitch and the trailer, shouting or signaling directional commands to the vehicle operator. This two-person approach is, however, prone to error as it is difficult enough for the to rear person to communicate the exact degree of the amount of leftward or rightward adjustment required, let alone for the driver to execute precisely. The result is most often over- or under-shoot, which forces the driver to pull forward and begin the alignment process anew. On an incline, such as a boat ramp, this procedure can be time consuming and hazardous. 
     Even after they are connected the vehicle/trailer tandem is difficult to maneuver, particularly when backing the trailer. The operator must turn the steering wheel of the tow vehicle in the direction opposite the desired direction of the trailer. Trying to make a tight turn in reverse can result in a “jack-knife”, wherein the tongue of the trailer ends up parallel to the bumper of the tow vehicle, making further backward movement impossible. Even backwards travel in a straight line can be difficult, as for example, when backing a trailer down a narrow boat ramp. In forward travel, tight turns are also difficult to negotiate, because the trailer wheels track inside of the arc taken by the wheels of the tow vehicle. In other words, the tow vehicle makes a “wider” turn than the trailer or conversely the trailer makes a “tighter” turn than the tow vehicle. Maneuverability problems are worst in small areas where the movements of the towing vehicle are restricted and the handling capabilities are diminished. 
     There have been efforts as far back as the turn of the century to improve trailer hitches by incorporating lateral movement capabilities into their design. For example, U.S. Pat. No. 1,162,949 to Olson shows a primitive example of a trailer hitch comprising a screw-shaft connected to a bevel gear assembly which enables the operator to laterally adjust the hitch from the operator&#39;s seat of the tow vehicle or tractor. 
     In addition, U.S. Pat. No. 1,221,086 to Olson discloses a further refinement to the laterally adjustable trailer hitch, wherein a steering mechanism connected to the front axle of the tow vehicle enables the operator to steer the trailer for improved maneuverability. 
     U.S. Pat. Nos. 1,235,082 to Von Brethorst, 1,450,526 to Timmis, and 2,917,323 to Mandekic further show simple mechanically activated mechanisms employing a horizontally disposed screw-shaft to achieve lateral movement of the trailer hitch. 
     An improvement to the mechanical devices referenced above is taught in U.S. Pat. No. 3,178,203 to Elliott. Shown is a trailer steering mechanism for the improved steering of a trailer accomplished by incorporating a threaded shaft into the attachment mechanism between the tow vehicle and trailer. In addition, Elliott &#39;203 teaches the use of an electric motor to power the threaded shaft. Operation of the motor is controlled from the cab of the truck by an electrical circuit. 
     Lacking in the prior art, however, is a device powered by an electric motor working through a positioning screw for wide degree of motion, an assembly of ratio gears for robust yet precise adjustment, or operable by a wireless remote control device from the cab or rear of the vehicle. Further, none of the references cited incorporate the screw shaft and its attendant components in an enclosed, protective housing which increases the useful life of the trailer hitch and offers a compact, clean design to satisfy appearance conscious consumers. In light of the foregoing, it would be of great advantage to create an improved adjustable trailer hitch which incorporates these and other advanced features, and which enables the operator of the tow vehicle to laterally adjust the position of the ball receptacle assembly to simplify hook-up and to enhance maneuverability. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a system for lateral adjustment of the ball receptacle assembly of a trailer hitch by linking said ball receptacle assembly to a motor driven positioning screw. 
     It is another object to enclose the positioning screw, electric motor, remote sensing unit, and all other internal operating components (to be fully described below) in a sealed housing to protect said components from wear caused by exposure, and to enhance the aesthetic appeal of the device. 
     It is yet another object of the present invention to control the lateral movement of the ball receptacle assembly by a wireless remote control unit. 
     A still further object of the invention is to mount the hitch to the rear of a towing vehicle by means of mounting brackets adaptable for use on a range of different tow vehicles. 
     According to the present invention, the above-described and other objects are accomplished by providing a trailer hitch with a laterally adjustable ball receptacle assembly. The ball receptacle assembly includes a motor driven positioning screw. The motor is powered by a 12-volt direct current electrical system and turns the positioning screw via a linkage comprised of ratio gears or through a coupling directly to the shaft. The ball receptacle assembly is mounted beneath a roller guide comprising a threaded transverse channel which engages the positioning screw. Clockwise rotation of the positioning screw causes the roller guide to move laterally rightward. Conversely, counter-clockwise rotation causes the roller guide to move laterally leftward. The roller guide carries the attached ball receptacle assembly through the course of its lateral movement. Lateral adjustment of the hitch eliminates the need for the lateral element of precision during hook-up, leaving the operator responsible only for the more easily addressed forward and rearward positioning of the vehicle to achieve proper alignment of the trailer and hitch. Further, the invention simplifies backing the vehicle/trailer tandem because the remote control device enables the operator to make fine tuning adjustments to the position of the hitch from within the cab of the tow vehicle. Finally, in forward travel, the invention improves maneuverability as lateral adjustment of the hitch while the vehicle/trailer tandem is in motion can be used to cause the trailer to track in the same arc as the turning tow vehicle. For example, when making a tight right turn, a rightward movement of hitch (as viewed from behind) causes the trailer to track out a wider arc through the turn than if no adjustment were made. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which: 
     FIG. 1 is an isometric view of the assembled trailer hitch assembly. 
     FIG. 2 is a cross-sectional view of the fully assembled trailer hitch. 
     FIG. 3 is a composite front and side cross-sectional view of the ball receptacle assembly and roller guide. 
     FIG. 4 is a top plan view of the fully assembled trailer hitch showing the rearward placement of the center positioning lock assembly. 
     FIG. 5 is a sectional view of the drive/motor end-cap as shown in FIG.  1 . 
     FIG. 6 is an alternative embodiment of the drive/motor end-cap wherein the motor engages the positioning screw at a ninety degree angle. 
     FIG. 7 is a cross-sectional view of the shaft/bearing end cap as shown in FIG.  1 . 
     FIG. 8 is a side sectional view of the ball receptacle assembly and roller guide within the main housing unit. 
     FIG. 9 is a cross-sectional view of the main housing assembly with the ball receptacle assembly and roller guide removed. 
     FIG. 10 is a side cross-sectional view of an alternate embodiment of the ball receptacle assembly and roller guide incorporating adaptations which make them compatible with a rack and pinion mechanism. 
     FIG. 11 is a side sectional view of the ball receptacle assembly and roller guide of the alternative embodiment within the main housing unit. 
     FIG. 12 is a top plan view of an alternative embodiment which comprises a stud for mounting to the support component of a class “A” trailer hitch. 
     FIG. 13 is a side sectional view of the alternative embodiment comprising a stud for mounting to the support component of a class “A” trailer hitch. 
     FIG. 14 is an isometric view of the components of a class “A” trailer hitch. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a perspective view of the trailer hitch assembly  2  of the present invention which incorporates a remote control mechanism  13  to facilitate the left and right lateral movement of the hitch&#39;s ball receptacle assembly. As an alternative to the remote control mechanism  13 , a control panel hard can be wired to the trailer hitch assembly  2 , the latter being accessible from within the cab of the tow vehicle to enable the operator to control the lateral movement of the hitch&#39;s ball receptacle assembly. Such lateral movement enhances steering capabilities of the trailer when backing-up, and compensates for misalignment of the hitch and trailer tongue during hook-up. As can be seen in FIG. 1, the internal configuration of the trailer hitch assembly  2  allows it to be contained within a housing that gives it the same outward appearance as a conventional trailer hitch. 
     As seen in the cross-sectional view of FIG. 2, the trailer hitch  2  comprises an elongate housing structure divided into a central chamber  4  flanked by end-caps  6 ,  8 . One of the end caps  6  forms a sealed housing for a bushing (or bearings) which seat the distal end of an elongate positioning screw  10 . The opposite end cap  8  forms a sealed housing for an electric motor which drives the positioning screw  10 . The positioning screw  10  lies horizontally within the central chamber between the bearing shaft and the drive motor. The positioning screw  10  drives a ball receptacle assembly  12  laterally along the outside of central chamber  4 . The central chamber  4  is defined by a slotted opening  92  that stretches lengthwise along its downwardly disposed face (also see FIG.  9 ). With further reference to FIG. 9, a dust cover  94  comprising a plurality of bristles is installed along the edge of the slotted opening  92  to protect the components within the central chamber. Referring back to FIG. 2, the external ball receptacle assembly  12  is connected to an internal roller guide carriage  14  projecting through the slotted opening  92 . The roller guide carriage  14  moves laterally along a horizontally disposed track  15  within the central chamber  4 . A center position lock assembly  16  is attached at the midpoint of the rear face of the central chamber  4 . Mounting brackets  18 ,  19  enable the trailer hitch to attach to the frame of a tow vehicle. It will be readily understood by those skilled in the art that the orientation of the slotted opening  92 , internal roller guide carriage  14  and associated features may be varied without deviating from present invention. For example, the slotted opening  92  may be located along the outer side of the housing, with internal roller guide carriage  14  projecting horizontally and rearwardly through the slotted opening  92 . These alternative orientations are considered to be within the scope and spirit of the present invention. 
     As best seen in FIG. 3, the roller guide  14  and ball receptacle assembly  12  are attached by a bracket  40 . The ball receptacle assembly  12  comprises a square socket  42  having a 2″ inside dimension, capable of accommodating a standard 2″×2″ hitch tongue. The bracket  40  is welded to the top surface of the ball receptacle assembly  12  and to the bottom face of the roller guide  14 . Alternatively, the socket  42 , bracket  40 , and roller guide  14  may be a single cast steel member. The roller guide  14  comprises a carbon steel carriage body  48  having the shape of a three-dimensional cross, and carries a centrally disposed transverse channel  44 . The transverse channel  44  is threaded and engages the positioning screw  10  as shown in FIG.  2 . The roller guide  14  rides on the positioning screw  10  as the positioning screw  10  turns. The roller guide  14  further comprises pairs of stainless steel wheels  46  which are mounted at the corners of the carriage body  48 . Four pairs of wheels  46  are thereby attached to the carriage body  48 . Pins  47  centrally disposed within each steel wheel  46  function as axles for the wheel assemblies. 
     The center position lock assembly  16  visible in FIG. 4 is mounted to the rear face of the central chamber  4  and locks the ball receptacle assembly  12  in the center position. The locking mechanism prevents lateral movement of the hitch assembly during transport. The center position lock assembly  16  comprises a lock which is retracted using an electromagnet and a spring loaded pin to lock when the electromagnet is not energized. In the center position, the electromagnet of the center position lock assembly is de-energized which locks the ball receptacle assembly  12  thereby preventing lateral movement. 
     The end cap  8  as shown in FIG. 5 forms a sealed housing for a drive motor  50  and linkage assembly which drive the positioning screw  10 . The drive motor  50  lies on the same axis as the positioning screw  10 , or alternatively may be offset ninety degrees relative to the positioning screw  10  as shown in FIG.  6 . An existing fractional horsepower parallel shaft  12  VDC electric motor provides adequate power for the unit. Alternatively, the motor may be hydraulically powered with flexible hydraulic fluid lines linking a control panel within the cab to the drive motor. The linkage assembly comprises a set of carbon steel ratio gears  54  directly connected to the drive motor  50  and positioning screw  10 . A shaft  52  extends from the positioning screw  10  from the central chamber  4  into the end cap  8 . The shaft  52  is circumscribed by a bronze bushing  56  at the junction of the central chamber  4  and end cap  8 . A bronze thrust washer  58  and rubber screw seal  59  circumscribe the positioning screw  10  at its juncture with the shaft  52  inside the central chamber  4 . 
     FIG. 7 shows the contents of the opposite end cap  6 , which forms a seal around the shaft  72  of the positioning screw  10 . The shaft  72  extends into the end cap  6  from the central chamber  4 . The shaft is circumscribed by a bronze bushing  76  at the junction of the central chamber  4  and end cap  6 . A bronze thrust washer  78  and rubber screw seal  79  circumscribe the positioning screw  10  at its juncture with the shaft  72  inside the central chamber  4 . 
     The wireless remote control device  13  of FIG. 1 enables the operator to actuate the drive motor  50 . Wireless remote control device  13  may be, for example, a conventional VHF or infrared transmitter matched to a corresponding receiver which controls the application and polarity of voltage applied to drive motor  50 . There are a variety of commercially available matched pair transmitters/receivers that are well-suited to this purpose. The remote  13  may be operated from within the cab of the tow vehicle or from outside. The remote  13  preferably comprises a setting to center the ball receptacle assembly  12 , plus right and left directional buttons. When a “L” or “R” directional button is depressed, the locking pin  34  in the center position lock assembly  16  is retracted and the motor is energized. Activation of the drive motor  50  causes the positioning screw  10  to rotate either clockwise or counter clockwise depending on the input from the operator at the remote control. Rotation of the positioning screw  10  moves the roller guide  14  laterally along the internal track  15  of the central chamber of the housing structure, thereby effecting lateral movement of the trailer hitch tongue. The system is effective for simplifying the hook-up process between a tow vehicle and a trailer and can be used while moving at slow speeds to improve maneuverability of the vehicle/trailer tandem. 
     The system as described herein is preferably powered by the existing automotive 12-volt electrical system. Alternatively, as mentioned previously a hydraulic system can be used to achieve lateral movement of the trailer hitch assembly. The positioning screw  10 , roller guides  14 , and thrust washers  78  are preferably stainless steel to prevent corrosion. 
     With all parts assembled as shown in FIG. 2, the trailer hitch  2  is mounted in conventional manner to the rear of a tow vehicle. A trailer hitch tongue (not shown) extends from the ball receptacle assembly  12  rearwardly toward the trailer. The ball receptacle assembly  12  projects downwardly through the slot  92  in the central housing structure, and attaches to the roller guide  14  within the central chamber  4 . The roller guide  14  is capable of moving laterally inside the central chamber  4  along the track  15  incorporated therein. Accordingly, any movement of the roller guide  14  is translated into movement of the ball receptacle assembly  12  and hitch tongue. 
     The above-described trailer hitch assembly  2  provides wide-field lateral adjustment of the ball receptacle assembly of a trailer hitch by linking said ball receptacle assembly to a worm-gear type positioning screw driven by an electric motor. The assembly of reduction (ratio) gears ensures precise left, right, or center adjustment, and the adjustment can conveniently controlled by the wireless remote control device  13  from either the cab or rear of the vehicle. Moreover, all of the operative parts (positioning screw, electric motor, remote sensing unit, and all other internal operating components) are protected in a sealed housing. This increases the useful life of the trailer hitch and offers a compact, clean design to satisfy appearance-conscious consumers. 
     FIGS. 10-11 show an alternative embodiment of the trailer hitch wherein a rack and pinion mechanism, instead of the positioning screw  10 , directs the movement of the roller guide  114 . As best seen in FIG. 10, a rack gear  60  is horizontally disposed within the central housing  4 . As in the previous embodiment, the ball receptacle assembly  12  mounts to a modified roller guide  114  and projects downwardly through a slotted opening on the downward face of the central housing. In this case, the roller guide  114  is adapted to mate with the rack gear  60 . Accordingly, the roller guide  114  is generally formed in the shape of a block conforming to the width and height dimensions of the interior of the central chamber  4 . The top surface of the roller guide  114  is defined by a toothed channel  80  as shown in FIG. 11, in which it receives the rack gear  60 . The roller guide  114  further comprises an integral electric drive motor  82  connected externally to a circular toothed gear  62  which meshes with the rack gear  60 . In operation, the electric motor  82  powers the circular gear  62 . Movement of the circular gear  62  along the rack gear  60  causes the roller guide  114  to move laterally left or right. Lateral movement of the roller guide translates into a corresponding lateral movement of the ball receptacle assembly  12  and hitch tongue as in the previous embodiment. 
     FIG. 14 illustrates a conventional class “A” trailer hitch. As further shown in FIGS. 12-13, the apparatus of the present invention can easily be adapted to accommodate such a standard class “A” trailer hitch with telescoping support component  134 . Either of the above-described embodiments may be adapted for class “A” trailer hitch by replacing the mounting brackets  18  and  19  of FIGS. 2 and 11 with a stud portion  132  centrally located on the front face of the housing  3  (see FIG.  12 ). With combined reference to FIGS. 12 and 13, stud portion  132  is a generally rectangular shaped, hollow projection which extends forwardly from the hitch toward the tow vehicle, and telescopes inside of the support component  134  of the class “A” trailer hitch. The stud portion  132  is defined by holes  132   a  and  132   b  on opposite vertical sides, which correspond to holes  134   a  (visible in FIG. 14 and 134 b  (obscured) found on opposing sides of support component  134 . A through bolt  138  engages holes  134   a ,  132   a ,  132   b , and  134   b  and secures the stud portion  132  within the support component  134 . In this manner, the hitch is easily coupled to and disengaged from a class “A” hitch mounted on the tow vehicle. This allows the user to mount the hitch to the rear of a towing vehicle by means of mounting brackets adaptable for use on a range of different tow vehicles. 
     Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims: