Abstract:
A shock absorbing trailer hitch attachment for vehicle protection is presented. A shock absorbing attachment is inserted into the trailer hitch receiver tube of any vehicle with an existing trailer hitch. The trailer hitch attachment contains shock absorbing capabilities and is designed to compress in order to reduce impact to the vehicle. Specifically, this attachment minimizes the amount of shock forces on a vehicle&#39;s bumper, via impact, between other vehicles, structures, and objects. The attachment does not require alteration of existing trailer hitch receivers and will add purpose to the routinely underutilized trailer hitch.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not Applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       FIELD OF THE INVENTION 
       [0003]    The present invention is a trailer hitch accessory. More particularly, it provides vehicle protection through a shock absorbing attachment within existing trailer hitch receiver tubes. 
       BACKGROUND OF THE INVENTION 
       [0004]    A trailer hitch receiver tube, also known as a tow hitch, is a device that is physically attached to the rear frame of a vehicle, in which a ball mount is inserted to enable towing capabilities. Many trailer hitches have an opening, or receiver, in which accessories or other attachment options may be inserted. Trailer hitch attachments come in different shapes and sizes, and can be used on any Class trailer hitch, which typically range in sizes from 1.25-2.5 inches. North American trailer hitches are classified by the Society of Automobile Engineers (SAE) and common classifications include Class I, II, III, IV, and V. 
         [0005]    Traditional trailer hitches are secured to a vehicle&#39;s chassis and are structurally designed to tow large, and at times heavy, loads depending on the make of the vehicle. Trailer hitches are capable of receiving a variety of attachment options. There is a large variety in the types of attachments that may be inserted into the square receiver tube or sleeve of a trailer hitch; some examples include: portable grills, sun protection shades, non-absorbing bumper extension steps, receiver tube covers or caps, cargo shelves, etc. While these trailer hitch accessories serve specific purposes, such trailer hitch attachments do not provide shock-absorbing capabilities and vehicle protection when the vehicle comes in contact with a vehicle, structure, or object. 
         [0006]    More often than not, trailer hitches are underutilized; for example, the receiver tube is generally empty and doesn&#39;t provide any benefit to the vehicle. Trailer hitches can be used to help protect the rear of a vehicle. Vehicles with trailer hitches have the ability to receive an attachment that can provide shock absorbing capabilities to help protect the bumper, and the bumpers of other vehicles. SUVs and pickup truck-beds may extend more than five feet from the cab, making it difficult for the driver to judge the distance between the vehicle&#39;s bumper and another object when backing up. Minor impacts and low speed collisions can have serious repercussions on a vehicle, and its bumper. The cost of repairing, or repainting, a vehicle&#39;s bumper can be very expensive and inconvenient. 
         [0007]    There are many trailer hitch accessories available that serve specific purposes, however, there is an absence of attachments that provide effective shock absorbing capabilities for use at all times. 
       SUMMARY OF THE INVENTION 
       [0008]    Vehicles attempting to parallel-park, reverse into parking spots, or drive backwards, are highly susceptible to bumper damage as the driver may not accurately judge the distance between the vehicle&#39;s bumper and other vehicles, structures, and objects. The shock absorbing trailer hitch attachment of the present invention is designed to fit into a vehicle&#39;s trailer hitch receiver tube and provide a resilient, resisting force upon impact, which will ultimately prevent or help to minimize damage to the bumper and vehicle. In the event that a vehicle hits another vehicle, wall, structure, or object, the shock absorbing trailer hitch attachment will absorb the impact resulting from low speed vehicle impacts or collisions. 
         [0009]    Current trailer hitch attachments fail to combine the functionality of bumper protection accessories into an efficient, lightweight, and compact mechanism that protects the vehicle&#39;s bumper, yet fits within the confines of the trailer hitch receiver. The trailer hitch attachment of the present invention comprises a resilient member, such as a coil spring, an accordion member or a folding member or other similar resilient structure, attached to a tubular member which may be inserted at least partially into the receiver hitch tube and may extend outward away from the vehicle bumper, so as to allow the resilient member to compress and thereby absorb energy upon an impact resulting from a low speed collision. In a collision, the resilient member compresses and retracts in the same direction as the force being applied by the obstacle struck, reducing the kinetic energy upon impact with the object. The trailer hitch attachment of the present invention is aesthetically pleasing and functional due to its size, utility, practical application, and relatively low cost to manufacture. 
         [0010]    The shock absorbing trailer hitch attachment contains a resilient member, which may for example be a non-rust compression spring or other structure having similar resilient functionality that will retract upon impact. It will prevent the vehicle&#39;s bumper from making contact with objects that might damage the bumper, and help to minimize damage that might be caused by a collision, due to the trailer hitch attachment&#39;s shock absorbing property. The trailer hitch attachment of the present invention is made for slow speed collisions/impact at low speeds and will protect both the vehicle and the impact source (wall, vehicle, planters, barriers, etc.). An end-cap is attached to the outer most edge of the shock absorbing trailer hitch attachment. The purpose of the end-cap is to make initial contact with an impact source, which will then cause the resilient member to retract and absorb the applied force resulting from the impact. The end-cap is constructed of hard plastic or rubber or other impact resistant material which will help to prevent marks/scratches on a vehicle or other object with which the end-cap comes in contact in the event of an impact. 
         [0011]    The trailer hitch attachment of the present invention may be used on factory and after-market trailer hitches and will be scaled to the size of the trailer hitch receiver tube openings, which may be for example, 1.25 inches, 2 inches, and 2.5 inch or other appropriate dimension. A vehicle with the trailer hitch attachment of the present invention installed shall be referred to as the “primary vehicle.” The shock absorbing trailer hitch attachment is used to prevent damage to the primary vehicle&#39;s bumper in the event that the primary vehicle hits or is hit by, a vehicle, structure, or object. In the event of an impact, kinetic energy is dissipated from the trailer hitch of the primary vehicle via the resilient member which absorbs some of the force of the impact and transfers the remaining force to the solid frame of the primary vehicle. 
         [0012]    The shock absorbing trailer hitch attachment can also be used on vehicles that currently have back-up assist technology, such as cameras and audible chimes. Such technologies are susceptible to malfunction (camera lens may be cracked or inoperable), may be miscalibrated, may be inoperable (camera lens may be dirty or otherwise obstructed) or may not be applicable (drivers may be hearing impaired and won&#39;t be able to hear the chimes). The shock absorbing trailer hitch attachment may be used to augment existing technologies and provides redundancy with regards to vehicle protection. The trailer hitch attachment of the present invention may serve as an additional sensor for the driver, who will sense the resistance if the attachment encounters an obstacle such as another vehicle, a wall or an object when the primary vehicle is moving in reverse. Upon sensing such resistance, the driver can stop the rearward movement of the primary vehicle and avoid what might otherwise be severe damage to the primary vehicle and/or the obstacle. 
         [0013]    When not being used to tow, the primary vehicle&#39;s trailer hitch does not provide any benefit to the primary vehicle. Vehicles equipped with the shock absorbing trailer hitch attachment of the present invention will be better prepared to avoid or reduce damage due to low speed rear end impacts and will thereby increase the usefulness of the often-times underutilized trailer hitch. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0014]    The following figures are practical illustrations of exemplary embodiments of the present invention, which do not limit the scope or objectives of the invention. The figures should be used in conjunction with the explanations in the following detailed description. 
           [0015]      FIG. 1  illustrates a conventional trailer hitch receiver. 
           [0016]      FIG. 2  is a three-quarter perspective view of one embodiment which shows the components of the shock absorbing trailer hitch attachment. 
           [0017]      FIGS. 3   a - d  illustrates various views of one shock absorbing trailer hitch embodiment with absorption capabilities provided by a compression spring abutted against the opening of the trailer hitch receiver tube. 
           [0018]      FIGS. 4   a - 4   b  shows cross-sectional views which demonstrate the shock absorbing capability of one embodiment. 
           [0019]      FIG. 5  is a three-quarter perspective view of a second embodiment which shows the components of the shock absorbing trailer hitch attachment. 
           [0020]      FIGS. 6   a - d  illustrates various views of the second embodiment of the shock absorbing trailer hitch attachment with a compression spring located inside of round tubes that are inserted into the trailer hitch receiver tube. 
           [0021]      FIGS. 7   a - b  shows cross-sectional views which demonstrate the shock absorbing capability of a second embodiment of the shock absorbing trailer hitch attachment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    The present invention is described in one or more embodiments in the following description with references to the Figures, where reference numerals denote the elements and components within the figures. The following documentation and drawings articulate the invention&#39;s scope and objectives, which cover alternatives, modifications, and equivalents in similar spirit and scope as supported by the appended, and equivalent, descriptions and claims. Those skilled in the art may recognize that suitable alternatives may be substituted for elements, components, or configurations of the present invention and those modifications will not deter from the scope, applicability, or objectives of the present invention. 
         [0023]      FIG. 1 , illustrates a conventional trailer hitch receiver tube.  FIGS. 2-4   b  represent one embodiment of the present invention illustrating its shock absorption capabilities via a compression spring resting against the opening of the trailer hitch receiver tube.  FIGS. 5-7   b  represent a second embodiment where the resilient member is a coil spring located inside of interlocking tubes that are inserted within the trailer hitch receiver. 
         [0024]    Referencing  FIG. 1 , a conventional trailer hitch receiver is illustrated. The trailer hitch is typically mounted to the chassis of a vehicle. The vehicle may be a car, truck, SUV, bus, golf cart, or other type of wheeled vehicle suitable for towing another vehicle or object. The receiver  1  portion of the trailer hitch is depicted in  FIG. 1 . 
         [0025]    The receiver  1  is comprised of a square tubular body  2 . The interior of the tubular body  2  is hollow. One end of the tubular body  2  is connected to the body of the receiver-type trailer hitch  3 . The openings of trailer hitches are measured in horizontal and vertical dimensions, for example, 1.25 inches for SAE Class I hitches to 2.5 inches for some SAE Class V hitches. 
         [0026]    Holes  4  and  5  are configured on the vertical walls of the square tubular body  2 . The holes  4  and  5  are configured to receive a retaining, or hitch pin  6 . The trailer hitch opening  7  receives the trailer connecting member  8  to attach a trailer for towing. Only the end of the trailer connecting member  8  is depicted. Holes  9  and  10  are aligned on an axis and configured on opposite sides of the trailer connecting member  8  to receive hitch pin  6 . 
         [0027]    The trailer connecting member  8  is sized to fit into the trailer hitch opening  7 . The trailer connecting member  8  is inserted into the trailer hitch opening  7  and the holes  9  and  10  on the trailer connecting member  8  are aligned with the holes  4  and  5  on the tubular body  2 . The locking hitch pin  6  is inserted through holes  4 ,  9 ,  10 , and  5  to securely connect the trailer hitch with the trailer connecting member  8 . 
         [0028]      FIG. 2  depicts components of one embodiment of the shock absorbing trailer hitch attachment of the present invention with the receiver  1  portion of the trailer hitch and the hitch pin  6 . In this embodiment, the resilient member of the trailer hitch attachment is a coil compression spring  11 . The spring  11  exerts a resilient, resisting force when an object comes into contact with the trailer hitch attachment, which helps to prevent damage to the vehicle and/or the object. This embodiment of the trailer hitch attachment further comprises a tubular member  12  having an outside diameter that allows insertion of the tubular member  12  into the trailer hitch opening  7  of the receiver square tubular body  2 . Holes  13  and  14  are aligned on an axis near one end of the tube  12 . The inner diameter of the spring  11  is the same size, or slightly larger than the outer diameter of the tubular member  12 . The spring  11  may be inserted over and secured to a portion of the tube  12  (at the end of the tube that does not have cross-holes  13  and  14 ). The location of the spring  11  on the tube  12  is important so that when the assembled trailer hitch attachment is inserted into the trailer hitch receiver opening  7 , the spring  11  will rest against the perimeter of the trailer hitch opening  7  and the holes  13  and  14  in the tube  12  will align with the holes  4  and  5  of the trailer hitch receiver tube. Any appropriate method for securely attaching the spring  11  to the tube  12 , including for example welding, fasteners, and/or indentations on the tube or a combination of such methods, may be among the methods used to securely attach the spring  11  to the tube  12 . The outer dimension of the tube  12  may be about the same nominal dimension as the hitch receiver tube, e.g., a tube with about a 2 inch diameter may be inserted into about a 2 inch by 2 inch square receiver tube. In this embodiment, the tube  12  allows the trailer hitch attachment to be secured to the trailer hitch receiver  1  via holes  13  and  14 . Holes  13  and  14  are on the same axis and are located near one end of the tube  12 . These holes  13  and  14  are the same size, or slightly larger than the corresponding holes  4  and  5  on the trailer hitch receiver  1  through which hitch pin  6  is inserted. The hitch pin  6  secures the tube  12  with attached spring  11  to the vehicle&#39;s trailer hitch receiver tube  2 . Once the combined spring  11  and the tube  12  are inserted into the vehicle&#39;s trailer hitch receiver tube  2 , the hitch pin  6  will be inserted through the holes  4  and  5  of the vehicle&#39;s trailer hitch receiver tube  2  and through holes  13  and  14  of the tubular member  12 , thereby securing tubular member  12  with attached spring  11  to the vehicle&#39;s trailer hitch. 
         [0029]    An end-cap  15  is the primary element of this embodiment that will make contact with an object, e.g., vehicle, structure, wall, etc. The end-cap  15  is secured to the outward facing end of the compression spring  11 . The bond between the end-cap  15  and the spring  11  may be made with any appropriate means, including for example welding or through the use of fasteners or a combination of welding and/or fasteners. The end-cap  15  may also be affixed to the inside of the spring  11 . The end-cap  15  is strong and durable, and may be made of any appropriate resistant material, including for example metal, hard plastic, rubber or similar material and/or combinations of such materials, as its function is to make contact with objects or obstacles at varying degrees of speeds and angles. Combinations of different materials may be employed in different locations on the end-cap  15 . For example, the outer edge portion of the end-cap may be rubber, plastic, or a similar material and the inner portion of the end-cap may be comprised of metal or other similar material and vice versa. A variety of different shapes and designs may also be used for the end-cap  15  to provide an aesthetic effect; provided the shapes and designs are suitable for the end-cap&#39;s intended purpose of limiting damage upon impact. The end-cap can also include corporate logos or company names. The order of assembly of the components of the trailer hitch attachment of this embodiment of the present invention may vary. For example, the end-cap  15  may be attached to the spring  11  before or after the spring has been attached to the tube  12 . 
         [0030]      FIGS. 3   a - d  illustrate various views of a fully integrated  FIG. 2  embodiment of the present invention. In these views, the shock absorbing trailer hitch attachment is secured to the trailer hitch receiver  1  as the hitch pin  6  has been inserted through the holes of the trailer hitch receiver tubular body.  FIG. 3   a  is a perspective view of the  FIG. 2  embodiment of the shock absorbing trailer hitch attachment secured to the trailer hitch receiver tube  2 .  FIG. 3   b  is an overhead view of the same embodiment.  FIG. 3   c  is a side view of the  FIG. 2  embodiment and  FIG. 3   d  is a frontal view. As shown in  FIGS. 3   a - 3   c,  the spring  11  is resting against the perimeter of the opening  7  of the hitch receiver tube  2 . As shown, the embodiment is secured to the vehicle trailer hitch and ready to absorb impact and resulting kinetic energy through the mechanics of the spring. 
         [0031]      FIGS. 4   a - b  shows a cross-sectional view of all components of the  FIG. 2  embodiment. The compression spring  11  is wrapped around the tube  12 . The spring  11  is situated on the tube  12  so that when the tube  12  is secured to the hitch, the edge  17  of the spring  11  will touch the perimeter of the opening  7  of the trailer hitch receiver into which the tube  12  is inserted. The two holes  13  and  14  (not shown) in the tube  12  may be slightly larger than the diameter of the two holes  4  and  5  (not shown) in the trailer hitch receiver  2  to account for slight measurement differences of different hitch models and/or manufacturers.  FIG. 4   a  depicts the embodiment in the ready position.  FIG. 4   b  shows the embodiment in the fully compressed position against the trailer hitch. The spring  11  universally compresses along its length around the tube  12  in the direction shown by the arrow when the end-cap  15  of this embodiment comes into contact with an object. 
         [0032]    In  FIG. 5 , a second embodiment of the shock absorbing trailer hitch attachment is depicted. Like the  FIG. 2  embodiment, this embodiment is also inserted into existing trailer hitches and utilizes a compression coil spring as a resilient member to help prevent vehicle damage. The mechanics of this second embodiment differ, however, as the compression coil spring is located within interlocking tubes. As shown in  FIG. 5 , this embodiment comprises two interlocking tubes  112  and  112 A which permit movement of the smaller tube  112 A in one direction. The diameter of the larger tube  112  permits its insertion into the opening  107  of the hitch receiver tube  102 , e.g., a round tube with about a 2 inch diameter can be inserted into about a 2 inch by 2 inch square receiver tube. Toward one end of the larger tube  112 , two holes,  113  and  114 , provide the means to secure the tube  112  with hitch pin  106  to the trailer hitch receiver  1 . These holes  113  and  114  toward one end of the larger tube  112  are about the same size as the corresponding holes  104  and  105  in the trailer hitch receiver tubular body  102 . The opposite end of the larger tube  112  has a rounded (inward) edge, which will interlock with the rounded (upward) edge of the smaller tube  112 A to create one interlocking elongated, telescoping tubular assembly in a manner well known to those skilled in the art. The larger tube  112  of this elongated, telescoping tubular assembly is secured to the trailer hitch receiver body  102  via hitch pin  106 , and extends outward from the trailer hitch receiver. 
         [0033]    The smaller tube  112 A provided for this second embodiment fits inside the larger tube  112 . The smaller tube&#39;s  112 A outer diameter is less than the inner diameter of the larger tube  112 , e.g., if the inner diameter of the larger tube  112  is about 1.7 inches, the outer diameter of the smaller tube  112 A is approximately 1.65 inches or less. At one end, the smaller tube  112 A has an edge that is rounded, or curved, upwards and will fit inside the larger tube  112 . This rounded upward edge of the smaller tube  112 A will rest against a rounded downward edge of the larger tube  112  in a manner well known to form an interlocking, elongated telescoping tubular assembly when the smaller tube  112 A is inserted into the larger tube  112 . The interlocking downward and upward edges secure the assembled tubes together and prevent their separation from each other when the assembly is secured to the trailer hitch receiver body. An end-cap  115  is secured onto the opposite end of the smaller tube  112 A. The end-cap  115  may be secured to the smaller tube  112 A through various securing techniques, such as for example, welding, fasteners, or clips or combinations thereof. 
         [0034]    The size of the compression spring  111  may be scaled according to the overall length of the trailer hitch attachment and the inner diameter of the tubes  112 ,  112 A. The compression spring  111  is positioned within the tubes  112  and  112 A with one end of the spring  111  resting against the hitch pin  106  and the other end of the spring  111  resting against the end-cap  115 . When the end-cap  115  comes into contact with an object, the spring  111  situated within both tubes  112  and  112 A will compress against the hitch pin  106 . 
         [0035]    It is important to describe the integration assembly process of the second embodiment as there are interlocking components. The upward facing edge of the smaller tube  112 A should be inserted into the end of the larger tube  112  near the two holes  113 ,  114 . The smaller tube  112 A should lock into place within the larger tube  112  as the rounded edges of both tubes will touch. The end-cap  115  is fastened to the non-interlocking end of the smaller tube  112 A. At this point, compression spring  111  may be inserted into the remaining open end of the larger tube  112  (the end near the two cross-holes  113 ,  114 ) and then into the smaller tube  112 A, so that one end of the spring  111  rests against the end-cap  115 . Once all the components have been integrated, the assembly may be inserted into the trailer hitch receiver tube  102  and secured to the trailer hitch receiver by inserting the hitch pin  106  through the hitch receiver holes  104 ,  105  as well as the holes  113 ,  114  of the large tube  112 . The order of assembly may vary as the spring  111  may be attached to the end-cap  115  before the end-cap  115  is secured to the non-interlocking free end of the smaller tube  112 A. 
         [0036]      FIGS. 6   a - d  illustrate various views of the fully integrated embodiment of  FIG. 5 . In these views, the shock absorbing trailer hitch attachment is shown secured to the trailer hitch receiver  101  as the hitch pin  106  has been inserted through both holes  104 ,  105  of the trailer hitch receiver tube  102 . The tubes  112 ,  112 A are integrated together and interlocked and an end-cap  115  is located on the outermost edge of the assembled embodiment. At this point, the embodiment is secured to the vehicle and ready to absorb impact, and resulting kinetic energy, through the mechanics of the spring  111 .  FIG. 6   a  is a perspective view of the  FIG. 5  embodiment of the shock absorbing trailer hitch attachment secured to the trailer hitch receiver tube  102 .  FIG. 6   b  is an overhead view of the same embodiment.  FIG. 6   c  is a side view of the  FIG. 5  embodiment and  FIG. 6   d  is a frontal view. 
         [0037]      FIGS. 7   a - b  show a cross-sectional view of all components of the  FIG. 5  embodiment of the present invention. These figures demonstrate the location and functionality of the components.  FIG. 7   a  shows the inner workings of the embodiment where the compression spring  111  is located within two tubes  112 ,  112 A with one end of the spring  111  resting against the end-cap  115  and the other end of spring  111  resting against the hitch pin  106 . The spring  111  and tubes  112 ,  112 A extend outward from the trailer hitch receiver and are designed to compress/collapse in a controlled manner.  FIG. 7   b  illustrates the embodiment&#39;s ability to absorb energy through compression. The spring  111  is fully compressed against the hitch pin  106  and end-cap  115 , within both tubes  112 ,  112 A. 
         [0038]    These embodiments of the present invention take seconds to install/uninstall and fit snugly into a trailer hitch receiver tube and protect the trailer hitch receiver&#39;s inner-walls from deterioration and wear caused by natural elements. A standard hitch pin  106  may be inserted into holes  104 , 105  of the trailer hitch receiver tube  102  and through the holes  113 ,  114  of tube  112  of the shock absorbing trailer hitch attachment in order to secure the trailer hitch attachment to the vehicle. In the event that the driver of the primary vehicle wishes to insert a ball hitch attachment for towing, or insert any other trailer hitch attachment, the shock absorbing trailer hitch attachment of the present invention can be removed from the trailer hitch receiver by removing the hitch pin  106 . 
         [0039]    The embodiments described are illustrative of the present invention. All embodiments may be fabricated from multiple components, of the same materials as described or different materials having similar properties, characteristics and functionalities. Embodiments of the present invention may be manufactured out of hard, resilient, and resistant materials capable of withstanding low speed collisions and impacts. Such materials may include for example but not be limited to iron, steel, stainless steel, chrome, silicon, acetal resin (hard plastic), rubber or equivalent materials having similar properties, characteristics and functionalities. The present invention may be made from hollow and/or solid materials or a combination of such materials that are strong enough, resilient enough and resistant enough to withstand the forces resulting from low speed vehicle collisions and impacts. Components of the shock absorbing trailer hitch attachment of the present invention may be constructed from many different materials or combinations of different materials that provide resilient, resistant and shock absorbing capabilities. Equivalent shock absorbing components and structures such as resilient accordion members and folding members may be substituted for the resilient spring to withstand forces created as a result of collision or impact. Although the primary function of the present invention is to provide shock absorbing capabilities for vehicles, its benefits in reducing and limiting damage due to collisions and impacts may also be used in a variety of other applications.