Abstract:
The present invention provides a trailer coupler lock assembly for securing a coupler whether attached to or detached from a hitch ball of a trailer or vehicle, the coupler attachable to the hitch ball supported by one of the trailer or vehicle, the locking assembly having a first bracket member and a second bracket member, each of the first and second bracket members having a locking tab with a locking bore. A hinge connects the first and second bracket members, the first and second bracket members having an open position and a closed position, the first and second bracket members configured to form a body receiving cavity disposable about the coupler and lock thereto when the first and second bracket members are in the closed position, the locking bores being disposed in axial alignment to receive the shackle of a padlock there through.

Description:
RELATED APPLICATION 
   The present application claims priority to U.S. Provisional Application 60/318,428 filed Sep. 10, 2001, and to U.S. Provisional Application 60/336,431 filed Nov. 1, 2001. 

   BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The present invention relates to the field of transport vehicles, and more particularly but not by way of limitation, to an improved lock assembly for securing a trailer coupler. 
   2. Discussion 
   A common means of expanding the hauling capacity of land based vehicles is by the use of a wide variety of trailers, including utility or flatbed trailers, box trailers, livestock trailers and travel trailers. While there are several means for coupling a trailer to a vehicle, two of the most common are the fifth-wheel hitch and the rear-mounted hitch ball hitch assembly, the latter being perhaps the most popular. While the hitch ball portion of a hitch ball hitch assembly can vary in size and mounting location, the vehicle portion of most hitch ball hitching assemblies is generally constant. However, the trailer coupler that connects to the vehicle hitch ball varies greatly in design. 
   Due to variation in trailer couplers there have been numerous prior art devices designed for securing hitch ball hitch assemblies to prevent theft and accidental detachment of the trailer from the vehicle. Such security devices are generally of two broad types, box or canister devices that cover all or a portion of the coupler assembly and those that function to prevent a hitch ball from entering the coupler by restricting access to the operating mechanism. Examples of the first type are taught by U.S. Pat. No. 6,244,080 issued to Ray, et al.; U.S. Pat. No. 6,202,453 issued to Disher, et al.; U.S. Pat. No. 6,070,441 issued to Bernstrom; U.S. Pat. No. 5,937,679 issued to Villalon, Jr.; U.S. Pat. No. 5,794,961 issued to Niswanger; and U.S. Pat. No. 5,775,139 issued to Sellers. Patents that teach security devices that prevent hitch ball insertion into a trailer coupler include U.S. Pat. No. 5,410,893 issued to Easterwood; and U.S. Pat. No. 4,186,940 issued to Pillars. 
   A problem associated with these devices is that they can only be used when the trailer is detached from the vehicle. Thus, for protection against theft when the trailer is attached to a vehicle, another security device must be used. Additionally, when the trailer is attached to a vehicle, these devices must be stored, risking being lost or stolen. 
   Devices that lock a trailer to a towing vehicle comprise another category of security devices. Methods of functioning vary and include plate or chain devices permanently attached to either the vehicle or trailer. Examples of these latter mentioned devices are taught by U.S. Pat. No. 6,155,589 issued to Simpson; U.S. Pat. No. 6,062,583 issued to Lauricella, Jr.; U.S. Pat. No. 5,956,980 issued to Jenkins; U.S. Pat. No. 5,947,506 issued to Bauer; U.S. Pat. No. 5,873,271 issued to Smith; and U.S. Pat. No. 5,700,024 issued to Upchurch. 
   Depending upon the design, such security devices often require extensive and usually professional installation to either the vehicle or the trailer. Another problem associated with many of these devices, especially to vehicle mounted devices, is that they do not provide theft protection for the trailer when the trailer is not attached to a vehicle. 
   Yet another category of prior art security devices comprise those that simply lock the pre-existing latching mechanism of the hitch. Examples of such security devices are taught by U.S. Pat. No. 5,540,065 issued to Wyers; U.S. Pat. No. 5,284,038 issued to Johnson; and U.S. Pat. No. 4,711,106 issued to Johnson. The major problem associated with these security devices is that they cannot be used to lock certain types of sliding collar, or sleeve, hitches due to there being no provision for locking. As appearing herein, the words collar and sleeve will be interchangeable as such appears to the custom in the industry. 
   Some sliding collar trailer hitches do have a bore through the hitch neck for the insertion of a safety pin, but the placement of the accompanying lock makes these devices susceptible to accidental or intentional damage. Further, since the diameter of the bore that is usually provided is relatively small (usually one quarter inch or less), the pin on the lock has to be small and thus is easily sheared by one intent on defeating the security. 
   One additional prior art device is taught by U.S. Pat. No. 3,820,823, issued to Beaston for a sliding collar trailer hitch. The device is disposed in a slot and held in place horizontally by a padlock on one side and a flange on the other side, and it operates to block movement of the collar. A particular problem with the arrangement of this structure is that severance of the operating rod frees the device. 
   Finally, U.S. Pat. No. 5,582,420, issued to Ulbrich, teaches a method for retrofitting hitches of the type taught by U.S. Pat. No. 4,133,553, issued to Pierce, to accept a padlock. While this design does provide a locking method, the device is vulnerable to tampering or damage to the operating rod, the lever or the interface between the two to release the sliding collar. Additionally, modification of the hitch is required for its installation. 
   SUMMARY OF THE INVENTION 
   The present invention provides a trailer hitch coupler lock assembly for securing a trailer coupler, whether attached to, or detached from, a vehicle, the coupler attachable to a hitch ball supported by one of the trailer or vehicle, the locking assembly having a first bracket member having and a second bracket member, the first bracket member having a locking tab with a first locking bore. The second bracket member has a locking tab with a second locking bore. A hinge connects the first and second bracket members, the first and second bracket members having an open position and a closed position, the first and second bracket members configured to form a body receiving cavity disposable about the coupler and locked thereto when the first and second bracket members are in the closed position, the first locking bore and the second locking bore being disposed in axial alignment to receive the shackle of a padlock there through. 
   The advantages and features of the present invention will be apparent from the following description when read in conjunction with the accompanying drawings and appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevation view of a conventional trailer coupler for which the present invention is suited to secure. 
       FIG. 2  is a fragmentary cross-sectional view of the trailer coupler of  FIG. 1  along line  2 — 2  with the hitch ball removed. 
       FIG. 3  is another side elevation view of the trailer coupler of  FIG. 1  having disposed thereon a trailer hitch coupler lock assembly constructed in accordance with the present invention. 
       FIG. 4  is front elevation view of the trailer hitch coupler lock assembly of  FIG. 3  along line  4 — 4  having the padlock removed there from. 
       FIG. 5  is a view in perspective of the trailer hitch coupler lock assembly of  FIG. 4  in its open position. 
       FIG. 6  is a fragmentary end view of the trailer hitch coupler lock assembly of  FIG. 4 . 
       FIG. 7  is a front elevation of another trailer hitch coupler lock assembly constructed in accordance with the present invention and mounted on a trailer coupler. 
       FIG. 8  is a perspective of the trailer hitch coupler lock assembly of  FIG. 7  shown in its open closed position. 
       FIG. 9  is a perspective view of the trailer hitch coupler lock assembly of  FIG. 7  shown in its open position. 
   

   DESCRIPTION 
   Referring particularly to  FIG. 1 , shown therein is a typical coupler  10  that is connectable to a conventional hitch ball  12 . The coupler  10 , as shown, is that taught by U.S. Pat. No. 4,133,553, and while the present invention finds particularly use with the coupler depicted, it will be understood that the present invention is not so limited. For complete understanding of the coupler taught in U.S. Pat. No. 4,133,553, that patent is incorporated herein by reference for such details of the coupler beyond the brief description provided herein. 
   As used herein, the term “coupler” is used for that portion of a hitch which attaches to a connecting member, such as a hitch ball member, and the coupler with the connecting member serve to interconnect a pulling vehicle and a following trailer or the like. The connecting member is usually mounted to the rear of the pulling vehicle with the coupler mounted to the following trailer, but the coupler can be mounted to the front of the trailer, and the coupler mounted to the rear of the vehicle. It will also be understood that when trailers are pulled in tandem, the leading trailer will have one of the connecting member and coupler, and the pulled trailer will have the other of the connecting member and the coupler. 
   With further reference to  FIG. 1 , and also to  FIG. 2 , the coupler  10  is formed from a body  14  and a cap  16 . The cap  16  has a pivoting front portion  18  which is hinged in a recessed portion  20  of the body  14  at a hinge  22 , and the pivoting front portion  18  is biased outwardly, or open, by a compression spring  23 . A collar  24  latches the body  14  and cap  16  in a closed position. A handle  26  engages a rear flange  28  of the collar  24 , the handle  26  being pivotally mounted on a tongue  30  behind a rear portion  32  of the body  14 . Some couplers are not equipped with a handle, such as the handle  26 , and the collar is simply hand manipulated. 
   The pivoting front portion  18  of the cap  16  fits in a recess  34  of the body  14 . A pin  36  extends laterally to the pivoting front portion  18 . The pin  36  fits in the aperture  38  extending to the interior recess  34  of body  14 . 
   The collar  24  is slideably mounted on the rear portion  32  of the body  14  and is biased to a closed position by a spring (not shown) internal to the collar  24  and that is coiled about the tongue  30 . This internal spring (not shown) has its back portion abutting a retaining ring (also not shown) attached to the tongue  30  and its front portion engaged with a rolled forward end  40  of the collar  24 . 
   In operation, the pin  36  extends into the interior recess  34  of the body  14  when the cap  16  is open. The hitch ball  12 , when inserted into the recess  34 , will be self-centered by its top surface; as the hitch ball  12  enters the interior recess  34 , the hitch ball  12  presses against the pin  36  and displaces it from the interior recess  34 . As the pin  36  is pushed out of the interior recess  34  the pivoting front portion  18  pivots around the hinge  22  and closes with respect to the body  14 . As the hitch ball  12  attains a self-centered position in the hollow hitch ball cavity, the protrusion pushes the cap  16  to a position wherein the collar  24  extends over the cap  16  and rear section  32  of the body  14 . The collar  24  automatically slides forward under pressure from its spring to move the cap  16  to its closed position. That is, the cap  16  is closed by the pressure exerted by the collar  24 , the pin  36  thereby being slightly recessed from the surface of the recess  34 . When the collar  24  is closed around the cap  16 , the hitch ball  12  is correctly seated in the interior recess  34  and the cap  16  clamps over the hitch ball  12 . 
   The tongue  30  pivotally supports the handle  26 , and when pivoted, the handle  26  will pull the collar  24  away from the cap  16 . That is, pivoting the handle  26  will move the collar  24  backward, releasing the cap  16  to assume an open position; the hitch ball  12  can then be disengaged from the coupler  10 . The spring  23  automatically opens the cap  18  when the collar  24  is removed rearward so that the hitch ball  12  can be removed from interior recess, or cavity,  34 . The cap  16  is incapable of being opened when the collar  24  slides forward over the cap  16 . 
     FIGS. 3 and 4  show a trailer hitch coupler lock assembly  50  constructed in accordance with the present invention and mounted on the coupler  10 . It will be noted that the tongue  30  of the coupler  10  has a shoulder  52  that is formed between that of the rear portion and the forward portion of the tongue  30 , the forward portion having a reduced diameter. The trailer hitch coupler lock assembly  50  is configured to mount over the forward portion of the tongue  30  between the collar  24  and the shoulder  52 . A padlock  54  secures the trailer hitch coupler lock assembly  50  as shown. 
   The trailer hitch coupler lock assembly  50  has a first bracket member  56  and a second bracket member  58  that are connected by a hinge  60 . The hinge  60  has a pin (not shown) that extends through axially aligned holes in the mating lower end portions  62 ,  64  of the first and second bracket members  56 ,  58 , respectively, as shown in  FIG. 5 . 
   The first and second bracket members  56 ,  58  are configured to form a cylindrically shaped, body cavity  66  that is dimensioned to receive the forward end portion of the tongue  30  of the coupler  10  therein. Each of the first and second bracket members  56 ,  58  has a locking tab  68  at its upper end, each locking tab  68  having a locking bore  70  there through. Each locking tab  68  is offset on its supporting bracket member so that the locking tabs  68  will be positioned in overlapping spatial relationship as shown in  FIG. 6 , when the first and second bracket members  56 ,  58  are closed, and whereby the locking bores  70  are axially aligned. 
   The locking tabs  68  are inset from the outer surfaces of the first and second bracket members  56 ,  58  by a predetermined inset distance “D” as depicted in  FIG. 6 . The purpose of the inset “D” is to provide increased strength to the locking tabs  68  and to protect the shackle of the padlock  54 . While a conventional padlock  54  is depicted in  FIG. 3 , it is recommended that a padlock be selected having a minimal shackle length to pass through the aligned locking bores  70 , lock and leave little or no shackle exposure. This will minimize the likelihood of a security breach from the shackle being severed. 
   As shown in  FIG. 4 , the first and second brackets  56 ,  58  form a handle notch  71  when in the closed position, and the dimensions of the handle notch  71  are determined to provide clearance over the handle  26  when the trailer hitch coupler lock assembly  50  is mounted to the coupler  10 . Further, the dimensions of the trailer hitch coupler lock assembly  50  are determined so that it is positioned to reside between the rear flange  28  of the collar  24  and the shoulder  52  of the tongue  30 . 
   The positioning of the mounted trailer hitch coupler lock assembly  50  prevents the rearward movement of the collar  24 , thereby locking the cap  16 . If the cap  16  is secured to the ball  12 , as when a trailer is attached to a pulling vehicle, the presence of the trailer hitch coupler lock assembly  50  will prevent disengagement of the coupler  10  from the ball  12 . If the cap  16  is not secured to the ball  12 , as when a trailer is not attached to its pulling vehicle, the presence of the trailer hitch coupler lock assembly will prevent engagement with the ball  12 , effectively insuring that the trailer can be used only by the owner. 
   An optional feature is the provision of a locking rod  72  extending from the internal surface of the first bracket member  56 . In this embodiment, a retaining bore  74  is placed in the tongue  30  as shown in  FIG. 4  in a location to receive the insertion of the locking rod  72 . The locking rod  72  and retaining bore  74  may be provided in those applications in which the prevention of rotation of the mounted trailer hitch coupler lock assembly on the tongue  30  is desired, such as when no handle  26  is provided with the coupler. 
   FIGS.  7  Through  9   
     FIG. 7  shows a trailer hitch coupler lock assembly  100  constructed in accordance with the present invention and mounted on tongue  30  of the coupler  10 . The trailer hitch coupler lock assembly  100  is configured to mount over the forward portion of the tongue  30  between the collar  24  and the shoulder  52 . Although not shown in  FIG. 7 , it will be understood that the padlock  54  can be used therewith to secure the trailer hitch coupler lock assembly  100  in the manner described above for the trailer hitch coupler lock assembly  50 . 
   The trailer hitch coupler lock assembly  100  has a first bracket member  156  and a second bracket member  158  that are connected by a hinge  160 . The hinge  160  has a pin (not shown) that extends through axially aligned holes in the mating lower end portions  162 ,  164  of the first and second bracket members  156 ,  158 , respectively, as shown in  FIG. 8 . 
   The first and second bracket members  156 ,  158  are configured to form a cylindrically shaped, body cavity  166  that is dimensioned to receive the forward end portion of the tongue  30  of the trailer coupler  10  therein. Each of the first and second bracket members  156 ,  158  has a locking tab  168  at its upper end, each locking tab  168  having a locking bore  170  there through. Each locking tab  168  is offset on its supporting bracket member so that the locking tabs  168  will be positioned in overlapping spatial relationship as shown in  FIG. 7 , when the first and second bracket members  156 ,  158  are closed, and whereby the locking bores  170  are axially aligned. 
   The first and second brackets  156 ,  158  form a handle notch  171  when in the closed position, and the dimensions of the handle notch  171  are determined to provide clearance over the handle  26  when the trailer hitch coupler lock assembly  100  is mounted to the trailer coupler  10 . Further, the dimensions of the trailer hitch coupler lock assembly  100  are determined so that it is positioned to reside between the rear flange  28  of the collar  24  and the shoulder  52  of the tongue  30 . 
   The positioning of the mounted trailer hitch coupler lock assembly  100  prevents the rearward movement of the collar  24 , thereby locking the cap  16 . If the cap  16  is secured to the ball  12 , as when a trailer is attached to a pulling vehicle, the presence of the trailer hitch coupler lock assembly  100  will prevent disengagement of the coupler  10  from the ball  12 . If the cap  16  is not secured to the ball  12 , as when a trailer is not attached to its pulling vehicle, the presence of the trailer hitch coupler lock assembly will prevent engagement with the ball  12 , effectively insuring that the trailer can be used only by the owner. 
   The trailer hitch coupler assembly  100  can be modified to include an optional feature of a locking rod  172  as shown in  FIG. 9  in which the trailer hitch coupler  100  is depicted in its open position. The locking rod  172  extends from the inwardly from the internal surface of the first bracket member  156 . It will be understood that, to use the trailer hitch coupler assembly  100  modified to have the locking rod  172 , the tongue  30  will need to be modified to have the retaining bore  74  as described above and shown in  FIG. 4  to receive the insertion of the locking rod  172 . The locking rod  172  and retaining bore  74  may be provided in those applications in which the prevention of rotation of the mounted trailer hitch coupler lock assembly on the tongue  30  is desired, such as when a trailer coupler does not have a handle such as represented by the handle  26 . 
   It will be appreciated that each of the embodiments described herein of the present invention is well suited to secure a wide variety of trailer hitch couplers of the type described herein without modification of such couplers. Thus, it is clear that the present invention is well adapted to carry out the objects and to attain the ends and advantages mentioned as well as those inherent therein. While presently preferred embodiments of the invention have been described in varying detail for purposes of the disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention disclosed and as defined in the above text and in the accompanying drawings.