Height adjustment hitch apparatus

A apparatus having a height adjustment mechanism to adjust the height of a trailer. The height adjustment mechanism is comprised of, among other elements, an outer tube, a crank assembly having a drive gear, an inner tube having an internally threaded acme nut, and an acme screw assembly. The acme screw assembly is linearly and cooperatively assembled such that the crank assembly causes the elongated acme screw to thread vertically through the internally threaded acme nut and the acme screw assembly to concurrently move vertically. The outer tube telescopically and slidably encases the inner tube, such that the outer tube can be vertically adjusted with respect to the inner tube when the crank assembly is operated. The trailer has a trailer hitch including a hitching end integrally secured to the outer tube outside surface, and is integrally attached to the trailer hitch at the trailer end. The trailer is adjusted vertically, concurrently when the crank assembly to the height adjustment mechanism is operated.

FIELD OF THE INVENTION

The present invention generally relates to an apparatus having a height adjustment mechanism coupled or mounted to a towing vehicle or unit, for adjusting the height of a trailer hitch to a trailer. In one aspect, the apparatus comprises a height adjustment device or coupling, said height adjustment device utilizing a hand crank being selectively cranked to permit height adjustment of a gooseneck hitch to a trailer.

BACKGROUND OF THE INVENTION

Apparatuses for height adjustment couplings for a trailer hitch are known. References in the related art are directed to forms of height adjustment devices or couplings; however, none of the related art references teaches the adjustment mechanism as proposed by the present invention.

Proper height adjustment to keep a trailer as level as possible is very important to the safe and efficient operation of any trailer by a towing vehicle or other towing unit. A level trailer distributes the weight evenly to all tires of the towing vehicle and trailer, creating a more stable and straighter trailer during towing, improving pulling performance. Tires in the trailer and towing vehicle will heat-up less and wear better, thereby lasting longer, when a trailer that is level distributes the load equally to all such tires. A level trailer distributes the weight of a load evenly between the axles of the trailer. Bent axles, broken axles, broken spindles, and broken leaf springs are often caused from excessive weight on one axle caused by unevenly distributed weight from a trailer that is not level. Trailer and towing vehicle brakes perform much better during towing when their weights are evenly distributed to all tires. A level trailer offers a more uniform load to each set of wheel bearings of the wheels to the trailer, creating a longer wheel bearing life for the trailer. In summary, keeping a trailer level, as in the present invention, enhances the wear, safety, and performance of the tires, the axles, the brakes, the wheel bearings, and pulling performance of the trailer and the towing vehicle.

Related art height adjustment apparatuses for towing trailers have many disadvantages. Such devices are limited by their complexity, often requiring two individuals to operate the apparatuses: one person to hold onto an adjusting sleeve, inner tube or other element of the apparatus and make the necessary height adjustment while a second person loosens and tightens set screws or bolts, resets cotter pins or manipulates other height adjustment, load-bearing support elements to said devices. This procedure frequently must be accomplished while the trailer is in a parked position and not coupled to a towing vehicle or other unit. Other related art devices are additionally limited by their safety concerns as well as complexity, requiring the operator to run a parking leg, jack or similar support to the trailer down with the trailer coupled to the towing vehicle, until most of the trailer weight is on the parking leg. The set bolts or other such height adjustment elements to such a device must then be loosened to raise or lower the trailer to the desired height and position using the trailer parking leg. After the desired height is attained, the set bolts are tightened and the parking leg is raised.

Frequently, these related art devices are located on the trailer rather than the towing vehicle or other unit, adding to the complexity of the height adjustment operation, and requiring more than one operator. The related art devices connected to the towing vehicle or other units are generally large and cumbersome, taking up an inordinate amount of room in said towing vehicles.

The operator must complete these complicated steps in the aforementioned related art apparatuses in proper sequence to avoid bodily injury and equipment damage. Such devices are severely limited, being inconvenient, inefficient, and/or unsafe. If their height adjustment is accomplished improperly, by the operator failing to properly fix the height adjustment element to the device or to position the trailer support prior to setting the height adjustment element, or by making another procedural error in hand-adjusting the device, the support features may fail causing injury to the operators or damage to the equipment. With set screw, bolt or cotter pin types of devices, two sets of such support elements are trusted to carry the entire weight of the trailer, a serious safety concern. Adjusting the related art set screw or other related art height adjustment elements requires too much time, too many wrench or other hand tool manipulations, can be difficult to maneuver, and have potential dangerous consequences as noted above. Most trailers are not adjusted to the correct level as a result of the complicated procedure, resulting in the wear, inefficient and safety problems noted above during towing.

Several related art references are directed to height adjustment mechanisms or couplings to trailer hitches. Each of U.S. Pat. No. 4,664,585 to Ambridge et al., U.S. Pat. No. 5,520,030 to Muldoon, U.S. Pat. No. 5,366,338 to Mortensen, U.S. Pat. No. 5,575,493 to Schwartz et al., U.S. Pat. No. 6,095,748 to Zachovich, and U.S. Patent No. 2004/0195801 to Lara disclose height adjusting mechanisms for a trailer hitch; however, none of the references teach the adjustment mechanism as proposed by the current invention. U.S. Pat. No. 5,520,030 to Muldoon discloses a gooseneck trailer locking device having a parking leg, leveling jack located on a trailer operated by a hand crank. U.S. Pat. No. 5,366,338 to Mortensen discloses a motorcycle towing/lifting device with a motorcycle jack operated by a hand crank gear. U.S. Pat. No. 6,095,748 to Zachovich discloses a vehicle lifting device operated by a camming crank. U.S. Pat. No. 4,664,585 to Ambridge et al. discloses a towing vehicle having a lifting beam.

None of these inventions to Muldoon '030, Mortensen '338, Zachovich '748, Ambridge et al. '585, or Schwartz et al. '493 provides the height adjustment elements of the present invention. The height adjustment element of Mortensen '338 discloses merely a lifting device having a winch strap, and that of Muldoon '030 discloses merely the leveling jack attached to the trailer, Zachovich '748 discloses a camming crank device having a riser pivot, Ambridge et al. '585 discloses two hydraulic rams secured to a lifting beam, and Schwartz et al. '493 discloses a hydraulic cylinder attached to a trailer; all of which references lack, and do not teach, the elements of the height adjustment mechanism of the present invention.

U.S. Patent No. 2004/0195801 to Lara and Mortensen '338 disclose load-bearing pins (Lara '801) or locking pins (Mortensen '338) for adjusting the height adjustment mechanism and bearing the load of a gooseneck hitch (Lara '801) or a towed motorcycle (Mortensen '338), which references do not teach the height adjustment mechanism of the present invention. Such related art requires hand tools to carry out the adjustments. Muldoon '030 and Schwartz et al. '493 require the need for a trailer mounted parking leg or landing gear, generally requiring more than one operator for quick, efficient, accurate, and safe height adjustments. Mortensen '338, Zachovich '748, and Ambridge et al. '585 all are complex and cumbersome in their operation, as towing devices, requiring a substantial amount of space and/or power from the towing unit. None of the devices to Muldoon '030, Mortensen '338, Zachovich '748, Ambridge et al. '585, Schwartz et al. '493 or Lara '801 operates in the manner of the present invention, and none of the references to those devices disclose the advantage of the internal screw gear height adjustment mechanism of the present invention. All of the aforementioned related art inventions suffer from one or more of the following disadvantages, set forth above: requiring more than one operator by being located on the trailer, being overly complex in its operation or cumbersome in its size, or by using load-bearing pins or screws or bolts.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a hitch apparatus installed to a towing vehicle or other unit, adapted to easily and quickly adjust the height of a trailer. The present invention is operated safely and quickly, in one embodiment, by a turn crank handle in one direction or the other to achieve the desired height adjustment.

Another object of the present invention is to provide a method to adjust the height of the hitch with the trailer coupled to the towing vehicle or other unit or with the trailer in a parked position, coupled or uncoupled from said towing unit.

A further object of the present invention is to provide a height adjustment hitch mechanism that may be safely utilized by one person with no tools required for adjustment, without danger to the operator or equipment. The present invention is convenient to use, accomplishing a height adjustment to the hitch in a few seconds with no tools required for adjustment. The present invention is very dependable, eliminating the requirement for pins, set screws, bolts or other load-bearing elements required in the related art for similar adjustments.

In one embodiment, the present invention provides an apparatus that includes a height adjustment mechanism made of hardened steal. Another embodiment includes said mechanism made of material to withstand at least 39,000 pounds of shear force. In another embodiment, the present invention includes a trailer that is a gooseneck trailer.

In another embodiment, the present invention provides a key keeper aperture to receive a key screw so that the height adjustment mechanism will secure the outer tube and the trailer hitch from inadvertent or unintentional lateral movement.

In another embodiment of the present invention, a free end of the crank handle provides a locking means to prevent inadvertent or unintentional vertical movement of the height adjustment mechanism and the trailer hitch.

In one embodiment of the invention, the height adjustment apparatus, in summary, is a height adjustment mechanism installed to a towing vehicle or other unit and attached by a trailer hitch to a trailer. The height adjustment mechanism is comprised of, among other elements, an outer tube, a crank assembly having a drive gear, an inner tube having an internally threaded acme nut, and an acme screw assembly. The acme screw assembly is linearly and cooperatively assembled such that the crank assembly causes the elongated acme screw to thread vertically through the internally threaded acme nut and the acme screw assembly to concurrently move vertically. The outer tube telescopically and slidably encases the inner tube, such that the outer tube can be vertically adjusted with respect to the inner tube when the crank assembly is operated.

The trailer has a trailer hitch including a hitching end integrally secured to the outer tube outside surface, and is integrally attached to the trailer hitch at the trailer end. The trailer is adjusted vertically, concurrently when the crank assembly to the height adjustment mechanism is operated, whereby the height adjustment apparatus of the present invention adjusts the height of the trailer.

Still further objects and advantages of the present invention will become apparent from a consideration of the ensuing descriptions and drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter with references to the accompanying drawings, in which the preferred embodiment of the invention is shown. This invention may, however, be embodied in different forms, and should not be construed as limited to the embodiment set forth herein. Rather, the illustrative embodiments are provided so that this disclosure will be thorough and complete, and will full convey the scope of the invention to those skilled in the art. It should be noted and will be appreciated that numerous variations may be made within the scope of this invention without departing from the principle of this invention and without sacrificing its chief advantages. Like numbers refer to like elements throughout.

Turning now in detail to the drawings, in accordance with the present invention, one embodiment of the invention, the height adjustment apparatus, is shown inFIG. 1, a partial side, elevational view of a trailer100having a trailer hitch101and a towing vehicle102, the towing vehicle102employing a height adjustment mechanism103according to the present invention. The towing vehicle102may be a truck or any other type of towing unit commonly used for towing a trailer, in other embodiments of the invention. The trailer100may be any type of commonly used trailer unit employing a gooseneck or similarly configured type of hitch in other embodiments of the invention. Different embodiments of the present invention include said height adjustment mechanism103constructed of any round, square, or other shaped, hollow tubing of any form of rigid material and construction well known and commonly used in the applicable art. As is apparent, the apparatus as set forth herein may be constructed from a variety of materials depending upon design considerations. For example, the use of high strength or hardened steels will yield an apparatus having high durability and strength to handle heavy trailer loads, whereas the use of other metals such as aluminum, will provide an apparatus having a light weight for ease of handling and use with lighter trailer loads. In the alternative, a combination of different materials may be used.

Referring toFIG. 2, one embodiment of the present invention, illustrated is a side, cross sectional, elevated view of the height adjustment mechanism103according to the present invention. The height adjustment mechanism103comprises an outer tube10having an outer tube top end11and an opposing outer tube bottom end12, and an outer tube inside surface28and an outer tube outside surface29.

Referring toFIG. 3, one embodiment of the present invention, a partially exploded and side, elevational and cross sectional view of a portion of the height adjustment mechanism103, illustrated is a pair of circular hubs16, opposingly disposed thru opposing shaft apertures35located in the outer tube10disposed toward the outer tube top end11; and a pair of circular bushings17opposingly disposed within said hubs16to cooperatively receive a drive shaft22and allow the drive shaft22to rotate within said hubs16. As shown inFIGS. 2 and 3, the pair of circular hubs16operate cooperatively with said bushings17to receive and secure the drive shaft22within the outer tube10.

FIGS. 2 and 3further depict a circumferential top plate ring18, having a top plate ring inner surface19and an opposing top plate ring outer surface54. Said top plate ring18is attached to the outer tube inner surface28and is located proximally to the pair of circular hubs16, toward the outer tube bottom end12.

Referring still further toFIGS. 2 and 3, a crank assembly20is depicted comprising a crank handle21operating cooperatively and integrally with the drive shaft22, and a drive gear23. As shown, the crank handle21has a free end24and an opposing drive shaft end25. As shown, as well inFIGS. 2 and 3, the drive shaft22has a crank shaft end36and an opposing tube shaft end37; attaches perpendicularly, cooperatively and integrally to the crank handle21at the drive shaft end25of the crank handle21; and is seated within the pair of circular hubs16, thru the outer tube10, and secured in place by said hubs16. Still referring toFIGS. 2 and 3, the drive gear23has a crank side26and an opposing drive gear side27, and is centrally and circumferentially located along the drive shaft22and within the outer tube10, operating conformably with the drive shaft22and having the crank side26oriented adjacent to the outer tube inside surface28. The crank assembly20is cooperatively and integrally assembled allowing the crank assembly20to turn in unison, when the crank handle21is acted upon by an operator.

Referring still further toFIGS. 2 and 3, one embodiment of the present invention, the outer tube10is operatively associated with and overlying an inner tube30having an inner tube top end31and an opposing inner tube bottom end32, and an inner tube inside surface38and an inner tube outside surface39. The outer tube10, as depicted, overlaps the inner tube30directionally from the inner tube top end31. The inner tube30is further comprised of an internally threaded acme nut33having a threaded inner nut surface34, said acme nut33circumferentially attached to the inner tube inside surface38, disposed for receiving a partially threaded, elongated acme screw41, and located proximally to the inner tube top end31.

Referring further toFIG. 2and toFIG. 4, one embodiment of the present invention depicting a side view of the height adjustment mechanism103and partially exploded view of the acme screw assembly40, the acme screw assembly40is shown comprising said elongated acme screw41suspensionally located and freely rotatable within the inner tube30and cooperatively engaged in the inner tube30within the internally threaded acme nut33, and having an acme screw top surface48and an opposing acme screw bottom surface49, and an unthreaded first rod surface46contiguous to the acme screw top surface48, and an unthreaded second rod surface47radially larger than said first rod surface46and radially smaller than a threaded screw surface109of said elongated acme screw41, and an acme screw threaded top surface57, said second rod surface47located contiguous to and between said first rod surface46and the acme screw threaded top surface57.

As shown inFIGS. 2,3and4, the acme screw assembly40further comprises a screw gear42circumferentially, cooperatively, and integrally fitted on the acme screw top surface48and around said first rod surface46by a fastening means55to cooperatively and differentially engage the drive gear23and concurrently drive said elongated acme screw41; a cylindrical top plate43having a top plate upper surface51and an opposing top plate lower surface52and a centrally located top plate aperture58thru said top plate43, said top plate circumferentially and cooperatively engaged onto said elongated acme screw41having said second rod surface47located through said top plate aperture58, and the top plate upper surface51located immediately against the top plate ring inner surface19. The cylindrical top plate43is secured to the outer tube10by a plurality of fastening means56, as depicted in detail inFIGS. 5A and 5B, other embodiments of the present invention.

The acme screw assembly40, as depicted inFIGS. 2 and 4, further comprises a thrust bearing44having an upper bearing surface50and an opposing lower bearing surface53, securely and circumferentially engaged around said second rod surface47and immediately, vertically beneath said top plate43; and a washer45interposed between the thrust bearing44and acme screw threaded top surface57, and around said elongated acme screw41, allowing the thrust bearing44to revolve freely about said second rod surface47.

As is apparent, shown inFIGS. 3,5A, and5B, different embodiments of the present invention include the fastening means55and the plurality of fastening means56comprising, respectively, threaded fasteners, such as screws, nuts, and bolts, or metal or other weldings, pins, rivets, and other such fastening means well known and commonly used in the applicable art. As depicted inFIGS. 2 and 3, the internally threaded acme nut33, an internally key screw15, the top plate ring18, and the pair of circular hubs16are attached to the inner tube30or the outer tube10, respectively, by the use of metal weldings or other suitable attaching means well known and commonly used in the art.

Referring toFIG. 6, one embodiment of the present invention, a perspective and partial side view of the height adjustment mechanism, the acme screw assembly40is linearly and cooperatively assembled allowing the screw gear42, thrust bearing44, washer45, and said elongated acme screw41to turn in unison. As further depicted inFIG. 6, the acme screw assembly40extends vertically above the inner tube top end31, and the drive gear23on the crank assembly20is situated immediately against and is differentially engaging the screw gear42on the acme screw assembly40for driving said elongated acme screw41. Further referring toFIG. 6, the crank assembly20causes the elongated acme screw41to thread vertically through the internally threaded acme nut33located in the inner tube30and the acme screw assembly40to concurrently move vertically when the drive gear23to the crank assembly20is activated by cranking the crank assembly20. Further referring toFIGS. 2 and 6, the top plate upper surface51engages the top plate ring inner surface19rendering the acme screw assembly40load-bearing to move the outer tube10vertically when the acme screw assembly40is activated by cranking the crank assembly20. As is apparent, different embodiments of the present invention include activating the crank assembly20and the crank handle21by manual or motorized cranking mechanisms or other means well known and recognized in the art.

Further referring toFIGS. 2 and 6, one embodiment of the present invention, the height adjustment mechanism103is linearly and integrally assembled, the outer tube10telescopically and slidably encasing the inner tube30, such that the outer tube10can be vertically adjusted with respect to the inner tube30when the crank assembly20is operated. Referring toFIGS. 1 and 6, andFIG. 7, one embodiment of the present invention, the height adjustment mechanism103is securely installed on a towing vehicle102by a mounting means104for securing the height adjustment mechanism103, said mounting means104located at the inner tube bottom end32of the height adjustment mechanism103for securing the height adjustment mechanism103by the plurality of fastening means56to the towing vehicle102. As is apparent, different embodiments of the present invention include a mounting means104comprising a ball hitch and mount, opposing plates welded to the height adjustment mechanism103and the towing vehicle102, respectively, and fastened by nuts and bolts or other fastening means, combinations of the foregoing ball hitch and plate devices, and other suitable trailer hitch/towing vehicle coupling assemblies commonly known and used in the art.

Referring again toFIGS. 1,7and8, the trailer100has a trailer hitch101including a hitching end105integrally secured to the outer tube outside surface39and a trailer end106. The trailer100, as depicted, is integrally attached to the trailer hitch101at the trailer end106. The trailer100is adjusted vertically, concurrently when the crank assembly20to the height adjustment mechanism103is operated, whereby the height adjustment apparatus of the present invention adjusts the height of the trailer100. The trailer hitch101is integrally attached to the trailer100at the trailer end106and to the height adjustment mechanism103at the hitching end105, respectively, by the use of metal weldings or other suitable attaching means well known and commonly used in the art.

To operate the height adjustment apparatus, a desired height to the trailer100is determined. Should a new desired height be determined, the outer tube10can be re-adjusted via the crank handle21relative to the inner tube30until a new, desired height of the trailer100is achieved. The elongated acme screw41being load bearing permits adjustability of the height adjustment mechanism103and therefore the entire height adjustment apparatus, while bearing the vertical load supplied by the attached trailer100, any accessories to the trailer100and any contents to the trailer100. These two functions are simultaneously and/or concurrently performed without relying on the force of friction to maintain the height or level adjustment of the height adjustment mechanism103.

In one embodiment of the present intention, the outer tube10, can maintain the desired height of the height adjustment mechanism103and concurrently bear all, or substantially all, of the vertical load of the attached trailer100, any accessories to the trailer100and any contents to the trailer100.

In one embodiment of the present invention, the height adjustment mechanism103is made of hardened steel. In another embodiment of the present invention, the height adjustment mechanism103is made of material to withstand at least 39,000 pounds of shear force.

In another embodiment of the present invention the trailer hitch101to the height adjustment apparatus as generally depicted inFIG. 1is a gooseneck trailer hitch to a gooseneck trailer.

Referring further toFIGS. 2 and 3, andFIG. 7, in another embodiment of the present invention, a key keeper aperture13is cooperatively disposed in the outer tube10and located toward the outer tube bottom end12, the key keeper aperture13having a threaded inner key surface14for cooperatively receiving the threaded key screw15. The inner tube outside surface39contains a key way107set vertically in the inner tube outside surface39to cooperatively hold said key screw15in place against the inner tube30, said key screw15lodging in the key way107and securing the outer tube10in place when said key screw15is screwed into the key keeper aperture13, co-axially aligning the inner tube30with the outer tube10, preventing lateral movement of the height adjustment mechanism103, thereby preventing the trailer hitch101from adjusting laterally inadvertently.

In another embodiment of the present invention, as depicted inFIG. 8, the free end24of the crank handle21is utilized as a locking means for preventing vertical movement of the height adjustment mechanism103. As shown inFIGS. 7 and 8, the crank handle21is reversibly attached to the drive shaft22by a fastening means55, and when reversibly attached the free end24of the reversely installed crank assembly20is held in place by the outer tube10, and thereby preventing the trailer hitch101from adjusting vertically inadvertently or unintentionally.

In another embodiment of the present invention, the invention provides a method of adjusting the height of the trailer100. Another object of the present invention is to provide a method to adjust the height of the trailer hitch101with the trailer100coupled to the towing vehicle102or with the trailer100in a parked position, coupled or uncoupled from said towing vehicle102, thereby adjusting the height of the trailer100. As is readily apparent, a further embodiment of the present invention as a method of adjusting the height of a trailer100is a method for leveling the trailer100.

Unless otherwise specifically stated, the terms and expressions have been used herein as terms of description and not terms of limitation. There is no intention to use the terms or expressions to exclude any equivalents of features shown and described or portions thereof. Various changes can, of course, be made to the preferred embodiment of the present invention without departing from the spirit and scope of the present invention. The present invention, therefore, should not be restricted, except to the following claims and their equivalents.