Patent Publication Number: US-2006016954-A1

Title: Visual aid for aligning a towing vehicle and a trailer hitch

Description:
FIELD OF THE INVENTION  
      The present invention relates to, a device for facilitating trailer hitch alignment, and in particular a visual aid apparatus for visually assisting an operator of a towing vehicle in maneuvering the towing vehicle in order to align a first trailer hitch component on the rear of a towing vehicle with a second trailer hitch component on a trailer.  
     BACKGROUND OF THE INVENTION  
      As a towing vehicle is maneuvered backward so that the trailer hitch component on the rear bumper is closely adjacent and vertically aligned with the hitch component on the trailer, a tool that facilitates the driver of the towing vehicle to observe the area in the vicinity of either one of the hitch components greatly improves the drivers ability to quickly and accurately position of the towing vehicle. There is a need for such a tool that is easily installed and removed. Furthermore, there is a need for a tool with flexibility, presently not available with similar prior art tools, that permits the tool to be readily installed on a wide range of diverse trailers and towing vehicles and then removed when not in use. This capacity is particularly important for some markets, such as mail order or Internet sales, where the tools may need to be purchased before having opportunity to try it and verify that it works with the particular towing vehicle or trailer.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. In the drawings:  
       FIGS. 1A through 1D  illustrate an embodiment of a visual aid device of the present invention and  FIGS. 1E and 1F  show alternate suitable implementations;  
       FIGS. 2A through 2E  depict visual aid embodiments of the present invention;  
       FIGS. 3A through 3C  illustrate an visual aid embodiment of the present invention that is comprised of an integrated warning mechanism capable of warning an operator of a towing vehicle that the towing vehicle has come into close proximity to the trailer; and  
       FIGS. 4 and 5  show examples of visual aids of the present invention installed in a manner to assist an operator of a towing vehicle maneuvering the vehicle backwards into correct alignment with a trailer.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Visual aid devices of the present invention are well suited for assisting an operator of a towing vehicle maneuvering the towing vehicle backwards to interconnect a trailer or the like. Devices of the present invention may be installed and removed from magnetic-sensitive planar surfaces, which are commonly found on towing vehicles, trailers and the like allowing visual aid device be a effective with a wide range of trailer types. Aspects of the present invention provide for easier installation and removal. Some aspects improve the capability of the visual aid to remain in place after being installed and other aspects provide for the visual aid to be secured to a more diverse range of surface types and orientations. Furthermore, certain aspects of the present invention provide for increased configuration options for positioning the mirror that improves the ability for visual aids of the present invention to be effective in a wider range of towing situations than similar prior art devices.  
      In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it is understood that the invention may be practiced without these specific details. In other instances, well-known mechanical components, electrical components, structures and techniques have not been shown in detail in order not to obscure the invention. Components referred to with reference designators consisting of numerals followed by a letter, are generally similar to the components referred to by the corresponding numerals, but vary slightly in function or physical structure as described in the associated description.  
       FIGS. 1   a  through  1   f  depict various alternate embodiments of a visual aid device  100   a  of the present invention. A visual aid  100   a  of the present invention is comprised of a mirror  130  that is pivotally attached to a support  110 . Support  110  is comprised of a base  120  that may be removably secured to any of a wide assortment of towing vehicles trailers and the like. In situations where an operator of a towing vehicle must back up the towing vehicle to mechanically interconnect a trailer to the rear of the towing vehicle, visual aid  100   a  may be installed in a manner that allows the mirror  130  to direct a selected field of view, of an area that is generally located behind the towing vehicle, to the line of sight of an observer sitting in the drivers seat of the towing vehicle.  
      Mirror  130 , in the disclosed embodiment shown in  FIGS. 1A, 1E , and  1 F, is comprised of a thin, rectangular, light-weight aluminum frame  134  that holds a thin, flat, rectangular mirrored glass  135  with an exposed reflective surface  132 . Exemplary embodiment shown in  FIGS. 1A through 1F , as well as  FIGS. 3 and 4 , which will be discussed later in this disclosure, utilize a mirror  130  with a flat rectangular reflective surface  132  that is about 7.5 inches by 5.5 inches. Exemplary embodiments shown in  FIGS. 2A through 2B  and  FIG. 5  (these figures are discussed in later in disclosure) employ a round mirror  130   a  with a 6 inch diameter reflective surface  132  that is convex to provide about 200% magnification. For purposes of this disclosure, a mirror axis  138  is defined as a line intersecting a centrally located point on the (round, rectangular or other shaped) reflective surface  132  of mirror  130  and lying perpendicular to the portion of the mirror in the vicinity of the intersecting point.  
      Visual aid devices of the present invention tend to be highly elongated and removably attached and thus small, light-weight mirrors advantageously diminish the inherent tendency of visual aid to tip in many towing situations due to external forces such as wind or gravity acting on the overall device. Embodiments of a visual aid consistent with the present invention may also include mirrors comprised primarily of plastic. The size, shape, and composition of suitable mirrors may be selected based considerations that include cost, weight, ruggedness, quality, and magnification of the reflective surface  132 . In general, for use in towing situations where the mirror is located more than 5 feet away from the observer, a flat reflective surface  132 , with an area that exceeds a 4 inch diameter, is minimally sufficient. It is advantageous to employ larger mirrors, but the maximum size is generally limited by considerations involving weight.  
      The base  120 , as depicted in  FIGS. 1A through 1F  and  FIG. 4 , provides for removable attachment of visual aid  100   a  to a magnetic-sensitive surface such as commonly located on a trailer or towing vehicle.  FIG. 1A  depicts a side view of base  120 ,  FIG. 1C  illustrates a lower view of base  120 , and  FIG. 1D  shows a breakaways section of section A-A of  FIG. 1C .  
      Base  120  is comprised of a magnet  122  having a thin, generally cylindrical shape defining a central axis, formed with a coaxially located central cylindrical void  128 . Base  120  is also comprised of a generally circular, thin steal cover  121 , which is fixedly attached via a bold  123  to the lower end  117  of support  110 . Magnet  122  and cover  121  each have an upper and a lower planar surface. The upper planar surface of the magnet  122  is coaxially affixed the lower planar surface of the cover  121 . As shown in  FIG. 1C and 1D , the lower exposed planar surface  126  of magnet  122  includes an area that is located essentially in a plane lying traverse with the central axis  128  of magnet  122  and is bounded by an outer  191  and an inner circle  190 .  
      Visual aid  100   a  may be removably attached to a towing vehicle, trailer or the like, by placing the lower exposed planar surface  126  of base  120  adjacent to a selected target attachment surface to engage in a magnetic bond. When attached to a target surface, the magnet axis  128  lies perpendicular to the attachment surface. Visual aid  110   a  may be selectively rotated about base axis  128  to select the desired angular orientation of visual aid  100   a.  One advantage of being able to select the angular orientation is to provide increased installation configuration options such as allowing visual aid  100   a  to be positioned to the side of the hitch component, for example, on a bumper of a towing vehicle.  
      Suitable magnets  122  are selected based on the particular application and considerations such as cost, rated pull force, and geometry. High pull forces provide the advantage of increased attachment force, but lower pull forces allow the visual aid to be removed easier and are less likely to damage painted surfaces. For many applications, the shape of thin and wide magnets  122 , such a magnet with a thickness to outer diameter ratio that is approximately 1 to 10 or more, advantageously provides the base  120  with a wide radius that tends to be more resistant to tipping compared to narrower magnets. Magnets  122  with outer diameters that are greater than 2.5 inches but less then 4 inches and have a rated nominal pull force generally in the range of 40 lb to 160 lb may suitable for use with many trailers and towing vehicles.  
      Support  110  further includes a telescoping portion  109  that is comprised of three strait tubular sections  111 - 113  arranged coaxially end-to-end. The diameter of sections  111 - 113  are progressively smaller to allow each of the two upper sections  112 ,  113  to slide into the next lower, adjacent, section in a telescoping fashion. Two adjustable locking nuts  114 ,  115  connect the center section  112  to adjacent sections  111 ,  113 . When each of the two locking nuts  114  and  115  are in an unlocked position, the support  110  is telescopically adjustable through a range of extended positions. The two locking nuts  114 ,  115  may be rotated from the unlocked position to a locked position to fix the length L of the support  110 . The range of available lengths L of support  110  is selected for visual aid  100   a  based on considerations that may include, overall weight of visual aid  100   a  and the intended flexibility of visual aid  100   a  to be effective in a wide range of diverse situations. In the particular exemplary embodiment shown in  FIGS. 1A through 1F , and  FIG. 4 , each of the three tubular sections  111 - 113  is about 18 inches long and the length L may be selected from the predefined available range of 20 inches to 56 inches. Tubular sections  111 - 113  may be comprised of aluminum, plastic, steel, or other materials selected based on concerns including the manufacturing cost, the weight of the mirror  130  and the desired overall ruggedness of the visual aid  100   a.    
      Mirror  130 , shown in  FIG. 1A , is pivotally affixed to the upper end  118  of support  110  via a ball-and-socket pivotal connector  136 . A bracket  144  is affixed on one end to the top of the telescoping portion  109  and the other end extends 1.25 inches laterally from the telescoping portion  109  and then bends 30° toward the base  120  to attach to the ball-portion of connector. The socket-portion of connector  136  is affixed, centrally, to the backside of mirror frame  134 . The axis of the ball and socket connector  136  deviates from the longitudinal axis of the telescoping portion  109  by approximately 60°. The axis  138  of mirror  130  may be adjusted within a predefined range to deviate as much as 30° in from the longitudinal axis of the ball and socket connector  136 .  
      Alternate embodiments of a visual aid  100   b,    100   c  of the present invention are shown in  FIGS. 1E and 1F . Visual aids  100   b,    100   c  employ mechanisms for pivotally attaching mirror  130  to support  110  that provide an additional range of configuration options. Visual aid  100   b  includes a bracket  154  that is affixed to the top end of the telescoping portion  109  with a screw and extends laterally to pivotally connect to mirror  130  through a hinge  152 . Hinge  152  permits the mirror  130  to tilt upward or downward about 90° to a select a position from a range that extends from the mirror axis  138  being parallel with base axis  128  (i.e. mirror  130  facing downward) to the mirror axis  138  of being perpendicular to the base axis  128  (i.e. mirror  130  facing to the side).  
       FIG. 1F  shows an alternate embodiment of a visual aid  100   c  that includes an 8 inch long, flexible tubular portion  164  adapted to have an adjustable shape that may range from having a straight longitudinal axis to being bent with one or more curve portions having a radius as small as 3 inches.  
      An enlarged view of a portion of the telescoping portion  109  is shown in  FIG. 1B , which includes an optional ruler  119  in the form of markings located along the telescoping portion  109  of the support  110  that provide a visual indication of length. Ruler  119  provides a handy tool for measuring the height of the trailer hitch. In many hitching situations, the ability to accurately measure the height of a trailer hitch is advantageous and the integration of the ruler  119  with visual aid  100   a  eliminates the need for a separate device to measure height.  
      Two alternate embodiment of an visual aid  100   d,    100   e  are shown  FIGS. 2A and 2B , that further provide additional possibilities for positioning the mirror  130   a  and increase the range of suitable target surface. Visual aid  100   d,  shown in  FIG. 2A , includes a elongated support  110   a,  an enhanced base  120   a  and a round mirror  130   a.  Support  110   a  is similar to the support  110  shown in  FIG. 1A , but is further comprised of a hinge  223  that pivotally couples the base  120   a  to the lower end  117  of support  110   a,  which allows the elongated support  110   a  to be selectively pivoted in the radial direction indicated by reference F allowing the angle A 1 , between the lower exposed planar surface  126   a  and the longitudinal axis of telescoping portion  109  to be selected from the range of 0° to 180°. Hinge  223  also includes a locking screw  423 . The angle A 1  may be fixed by rotating the locking screw  423 .  
      Visual aid  100   e,  shown in  FIG. 2   b,  includes a support  110   b  that is comprised of a flexible tubular portion  220  that may be selectively bent, in any direction, on a curve having a diameter as small as 3 inches. The shape of flexible tubular portion  220  can be selected to be primarily strait or alternatively with one or multiple bends. The shape of flexible tubular portion  220  may be selected to determine the horizontal and vertical distance between mirror  130   a  and base  120   a  as well as the angular relationship between mirror axis  138  and the lower exposed planar surface  126  of base  120   a.    
      The alternate embodiment of base  120   a,  that is employed by visual aids  100   d,    100   e,  provides visual aid  100   d,    100   e  with increased resistance to tilting when installed. Aspects of the present invention, embodied in base  120   a,  provide for increased resistance to sliding and tends to reduce the likelihood of damage to the target attachment surface.  FIG. 2C  depicts a lower view of base  120   a.    FIGS. 2D and 2E  show the same cross sectional view of the base  120   a  in two different relationships to a target attachment surface  290 . Base  120   a  is comprised of a thin, cylindrical magnet  122   a,  a flat circular cover  121   a,  and a flat, donut shaped rubber pad  224 . Magnet  122   a  is similar to previously described magnet  122  and includes a lower exposed planar surface  126   a.  Magnet  122   a  has a 3.5  inches outer diameter. Pad  224  has a  5.5 inch outer diameter, an approximately 3.5 inch inner diameter, and an exposed lower planar surface  127 . Pad  224  and magnet  122   a  are in coaxial arrangement, each with the upper planar surface filmily adhered to the lower surface of cover  121   a.  Pad  224  has a thickness that is approximately the same as the thickness of the magnet  122   a.    
       FIG. 2A  shows base  120   a  secured to a planar attachment surface  290 . After being secured to trailer or hitch, base  120   a  may be removed by tilting the base  120   a  as shown in  FIG. 2   e  in order to break the magnetic bond to the target attachment surface  290 . As the visual device  100   d,    100   e  is tiled to break the magnetic bond, a portion of the exposed outer surface  226  of the pad  224  functions as the fulcrum  250 . The material comprising pad  224  is advantageously selected to be resilient so that it resist scratching of the attachment surface  290 . Also pad  224  has a larger diameter than magnet  122  and this results in an increased distance R between the fulcrum and the base axis  128  then would occur if the pad  224  was absent. Increasing the distance R tends to further inhibit undesirable tilting of visual aid  100   d,    100   b  after being installed.  
      Alternative embodiments of pad  224  may have a lower exposed surface  127  that extends 50 to 125 thousandths of an inch beyond the lower exposed surface  122  of magnet  120 . The material comprising a pad  224  that extends beyond magnet must be sufficiently compressible, such as sponge rubber or the like, so that the lower exposed surface  122  of magnet  120   a  makes good contact with the target attachment surface  290  when installed. The thickness of pad  224 , the texture of the exposed surface  127 , and the resiliency and compressibility of the materials comprising a pad  224  of the present invention may be selected for some intended uses such that the pad tends to increase the friction between the base and a smooth target attachment surface reducing the tendency for visual aid  100   d,    100   e  to slide laterally. Increased friction is beneficial or situations where visual aid  100   d,    100   e  is installed on a smooth inclined surface.  
       FIGS. 3   a  through  3   c  illustrate a visual aid  100   f  embodying the principles of the present invention, which includes an integrated warning mechanism capable of warning an operator of a towing vehicle that the towing vehicle has become into close proximity to the trailer. Visual aid  100   f  is similar to the previously described embodiment  100   a  (shown in  FIG. 1A ), but is further comprised of a visual indicator  371 , which is in this embodiment is implemented with a red light  371  (light bulb encased in translucent red plastic). Visual aid  100   f  is also comprised of a distance detector  352   a,    352   b.  A basic distance detector  352   a  is shown in  FIG. 3A . An enhanced distance detector is shown in  FIGS. 3B, 3C  and  FIG. 5 , that includes an extension  380  adapted to increase the usability of the warning mechanism. Distance detectors  350   a,    350   b  are based on low-cost mechanical solutions; however, well-known, electro-mechanical solutions are also suitable for some applications.  
      Visual aid  100   f  is further comprised of batteries (not shown) that are optionally disposed in the base  120   a  and a 3 foot electrical cord  351  that links the detector  352   a,    352   b  to the base  120   a.  Both alternate embodiments  352   a,    352   b  of a detector include, a small magnetic strip  353  that is disposed on detector  352   a,    352   b  to provide removable attachment to a magnetic sensitive surface. Alternate embodiments of the present invention provide adhesive for permanently affixing the detector  352   a,    252   b  to a selected location.  
      Each alternate embodiments  352   a,    352   b  of a detector include a particular version of an electrical, two-pole, momentary switch  351  (shown only in  FIG. 3C ) that electrically couples the batteries, and light bulb  371 , in series, via a pair of electrical conduits (not shown) that route through the support  110  and the 3 foot electrical cord  351 . Switch  351  includes a button  354  that response to being pressed by turning the red light bulb  371  on. In operation, detectors  350   a,    350   b  may be selectively positioned so that the button  354  is pressed when the towing vehicle and trailer become a predefined distance from the other. Optionally, the electrical cord  351  may include connectors for removing the cable when it is not being used.  
      Detector  352   b  includes an extension  380  that may be adjusted to increase the spatial range detector  350   b  is sensitive to and provides greater options for configuring visual aid  100   f  as will be described latter. Suitable extensions may take many forms. In the embodiment of a detector  352   b,  extension  384  is implemented as a 14 inch long bar bent, at a point 3 inches off longitudinal center, into a “V”-shape having a 115° angle and composed of resilient material such as, for example, a 3/16 diameter bar of an aluminum alloy encompassed within a thin plastic sheath.  
      Detector  352   a  is further comprised of a case  391  and a helical spring  362  that is mounted in case  391  and disposed to exert pressure tending to move switch holder  393  toward position P 3  shown in  FIG. 3C . Extension  380  is mechanically coupled to switch  351  through a bracket assembly  387  that includes a arm section  394 . Sufficient force to overcome the weak compressed spring  361 , particularly directed, will cause arm section  394  of bracket assembly  387  to move (in the direction indicated by reference M) a distance D 1  (0.25 inches) from position P 5  to position P 6 . This action causes arm section  394  to press on button  354 , closing switch  351  to turn the light bulb  371  on. After arm section  394  moves into position P 6 , continued force, sufficient to overcome the stronger helical spring  362 , causes the switch holder  393  to move (in the direction indicated by reference N) from position P 3  towards position P 4 . The sensitivity range of detector  352   b  corresponds to the distance D 2  between positions P 3  and P 4  illustrated in  FIG. 3C . The sensitivity range in this embodiment is 3 inches, however, sensitivity ranges from 3 to 8 inches are generally suitable for most towing applications. The sensitivity range is further expanded by the ability of the extension  384  to bend under pressure to have an angle that is less than 115° as shown in  FIG. 3B  by alterative position P 2 . The sensitivity range is effectively increased by the distance D 3  between extension  384  in the uncompressed state (position P 1 ) and extension  384  in the compressed state (position P 2 ).  
      Detector  352   b  is further comprised of a locking screw  385  that may be rotated to selectively fix the position of extension  380  with respect to the bracket assembly  387 . When locking screw  385  is in the unlocked position, the position of the extension  374  is adjustable by selectively sliding the extension in the direction indicated by reference K or rotated in the radial direction indicated by reference J. An exemplary operation is described later in connection with  FIG. 5 .  
       FIGS. 4 and 5  illustrate visual aids  100   d,    100   f  of the present invention installed in a manner advantageous to the operator of a towing vehicle  900 ,  700  maneuvering the towing vehicle backwards to connect a towing vehicle  900 ,  700  to trailer  800 ,  600 . A ball type hitch component  973 ,  773  on the rear of the towing vehicle  900 ,  700  is to be vertically aligned with a corresponding socket type component  864 ,  664  on the forward portion  813 ,  613  of a trailer  800 ,  600 . Thereafter, the forward portion  813 ,  613  of the trailer  800 ,  600  can be lowered so that the ball  973 ,  773  is received into the socket  864 ,  664  connecting towing vehicle  900 ,  700  to trailer  800 ,  600 .  
       FIG. 4  shows part of an exemplary boat trailer  800  and towing vehicle  900  as the towing vehicle  900  is being moved backwards. Visual aid  100   f,  as described in connection with  FIG. 3A , is installed to assist the driver in determining when the correct alignment between hitch components  864 ,  973  is achieved. Visual aid  100   f  is removably attached to an upward facing surface  815  located on the forward portion  813  of the trailer  800 .  
      The trailer  800 , in this application includes a mechanism  836  for adjusting the distance the trailer hitch component  864  resides above the ground. Visual aid  100   f,  which includes the optional ruler  119  illustrated in the detail of  FIG. 1B , may be placed horizontally with the base  120  on the ground (not shown in this position) to provide a handy tool to measure the height of the trailer hitch component  864  while the height is being adjusted.  
      After the height if the hitch component  864  is set, visual aid  100   f  may be secured to trailer  800 , as shown in  FIG. 4 , by placing the lower exposed magnet surface  126  of base  120  in magnetic engagement with the upward facing surface  813 , which may be slightly inclined. The axis  138  of mirror  130  may be positioned so that reflective surface  132  directs a selected field of view, comprising an image of the trailer hitch component  864 , to the line of sight  442  of an observer sitting in the driver&#39;s seat of the towing vehicle  900 . The projected image indicates to the operator of the towing vehicle  900  when the hitch components  864 ,  973  are properly aligned.  
      Visual aid  100   f  incorporates a warning mechanism with an enhanced distance detector  352   b  and a light bulb  371  as described earlier in this disclosure. The distance detector  352   b  is secured to a side surface  814  on the forward most portions  813  of trailer  800  and the extension  380  is adjusted to where a point  381  on the extension  380  will contact the rear portion  975  of the towing vehicle  900  as the vehicle  900  is maneuvered backwards. The distance detector  352   b  may be configured to indicate when the towing vehicle  900  has moved into the correct position. Alternatively the position detector  352   b  may be configured (not shown in this configuration) to warn the operator when the towing vehicle  900  has moved in to an undesirable position.  
      As the towing vehicle  900  is moved further backwards (not shown in this position), a rear surface  975  of towing vehicle  900  makes contact with the extension  380  and the light bulb  371  turns on. The towing vehicle  900  is permitted to continue to move backwards an additional 3 inches and the light bulb  371  will remain on; however, if the towing vehicle  900  moves backwards more than 3 inches, the distance detector  352   b  may be dislodged from the trailer hitch  800 .  
       FIG. 5  depicts a visual aid  100   d  that is described earlier in connection with  FIG. 2A . Visual aid  100   d  is shown installed on a non-horizontal surface  726  of a towing vehicle  700 . To install visual aid  100   d,  base  120   a  is placed in close proximity to the target attachment surface  726 . The position of mirror  130   a  may also be adjusted to select the desired position and orientation of mirror  130   a  so that a field of view comprising an image of the towing vehicle hitch component  773 , is directed to the line of sight  442  of an observer sitting in the driver&#39;s seat of the towing vehicle  700 . The position of mirror  130   a  may also be adjusted to position the center-of-gravity of visual aid  100   d  such that the force of gravity does not dislodge base  120   a  from the target attachment surface  726 . The position of mirror  130  is determined by: (1) adjusting the length L of support  110   a,  (2) selecting the orientating the mirror&#39;s axis  138 , and (3) by rotating the base  120  about its axis  128  to select the desired angular orientation of the visual aid  100   d.  The base  120   a  may be selectively rotated about its axis  128  by tilting base  120   a  (as shown in  FIG. 2E ) to break the magnetic attachment grip, rotating the base to the desired orientation, and then placing the base  120   a  flat to magnetically reengage the target attachment surface. As the towing vehicle  700  is moved backward, the forward extension portion of a trailer  613  enters the field of view projected to the observer and provides an indication of when the hitch components  773 ,  664  are properly aligned.