Abstract:
A ball and ring hitch lock to reversibly obstruct a ball socket or ring of a trailer hitch in order to prevent the theft of an unhitched trailer. The ball and ring hitch lock comprises an upper plate and a base plate attached by means of a secure rachet type system. A male hitch anchor is attached to the base plate. The male hitch anchor is sized to fit into a ball or a ring type hitch.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/363,272, filed Mar. 11, 2002. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to anti-theft devices. More specifically, the invention is a ball and ring hitch lock to prevent unauthorized control and use of a trailer, particularly an unhitched trailer, with either a ball or ring type hitch. 
     2. Description of the Related Art 
     Trailers, such as boat carrying trailers, utility trailers, construction equipment trailers, military trailers, and camping trailers, are typically left unattended for long periods of time and as such are extremely vulnerable to theft. A trailer may be left hitched to a vehicle&#39;s hitch point in the vain hope that the extra effort required to unhitch the trailer would discourage a trailer thief. However, the extra effort to unhitch the trailer is not likely to be a deterrent to a determined trailer thief. An owner may adopt more extreme measures such as removing wheels to immobilize a trailer; while such efforts can meet with success in preventing a theft the owner is never-the-less seriously inconvenienced when he or she wants to use the wheelless trailer. Clearly there is a need for a more convenient way of protecting a trailer from theft. 
     There are trailer anti-theft devices on the market such as the Fulton™ trailer lock (part no. CSTP17) available from Fulton™, Mosinee, Wis. 54455-0008. However, such products are unable to protect trailers fitted with either ring or ball type hitches, which can present problems for trailer owners. For example, a trailer owner who replaces a trailer with a ball type hitch with a trailer with a ring type hitch may be obliged to buy an anti-theft device that fits the new trailer hitch. Thus, there is a need for an anti-theft device that can work with both types of hitches, i.e. a ball and/or ring type hitches. 
     Several efforts have been made to address these problems. U.S. Pat. No. 4,459,832, issued to Avrea et al on Jul. 17, 1984 describes a pivotally mounted coupling guard, extending over a ball engaging socket of a trailer hitch to preclude disengagement of the socket from the ball. On information and belief the &#39;832 patent does not teach or suggest a dual anti-theft device suitable to prevent theft of a trailer with a ring hitch. 
     U.S. Pat. No. 6,467,317, issued to Hillabush et al. on Oct. 22, 2002 describes a lunette trailer hitch lock which prevents theft of trailers and other objects equipped with a lunette-style trailer coupler hitch having a lunette eye. The &#39;317 patent does not teach or suggest an anti-theft device suitable to prevent theft of a trailer with either a ball or ring hitch. 
     U.S. Pat. Nos. 3,780,546, 3,844,143, 3,884,055, 4,186,575, 4,440,005, 4,480,450, 4,577,884, 4,581,908, 4,730,841, 4,774,823, 4,836,570, 5,063,759, 5,195,339, 5,332,251, 5,343,720, 5,743,549, 5,752,398, 5,775,139, 5,794,961, 5,873,271, 5,937,679, 6,070,441, 6,202,453, and 6,405,569 each describe anti-theft devices for trailers, but none of these patents teach or suggest a ball and ring hitch lock according to the present invention. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a ball and ring hitch lock solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     A ball and ring hitch lock to reversibly obstruct a ball socket or ring of a trailer hitch in order to prevent the theft of an unhitched trailer. The ball and ring hitch lock comprises an upper plate and a base plate. The upper plate has a lower surface, and a first and second opposite ends, with a post that extends in a normal direction from the-lower surface of the upper plate. The post has a plurality of notches defined therein. The base plate has an upper surface and a sleeve with a hollow bore. The sleeve extends in a normal direction through the base plate and has a side opening defined therein. The sleeve is sized to accommodate the post extending from the upper plate. A lock mechanism is disposed in the base plate. The lock mechanism has at least one catch. When the lock mechanism is in a locked position the at least one catch extends into the side opening of the sleeve to engage at least one of the notches defined in the post in order to prevent removal of the base plate from the post. When the lock mechanism is in an unlocked position the at least one catch retracts from the sleeve in order to permit removal of the base plate from the post. A male hitch anchor is attached to the upper surface of the base plate. The male hitch anchor is sized to fit into a ball or a ring type hitch. 
     Accordingly, it is a principal object of the invention to provide an anti-theft device adapted to prevent the theft of an unhitched trailer. 
     It is another object of the invention to provide a ball and ring hitch lock to reversibly obstruct a ball socket or ring to prevent the theft of an unhitched trailer. 
     It is a further object of the invention to provide a robust ball and ring hitch lock comprising an upper plate, and a base plate combined with a lock mechanism adapted to engage at least one notch defined in a post extending from the upper plate in order to prevent separation of the base plate from the upper plate and visa versa. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an environmental, perspective view of a ball and ring hitch lock hooked up to a ring type trailer hitch according to the invention. 
     FIG. 2 shows a perspective view of the two main parts of the ball and ring hitch lock of FIG.  1 . 
     FIG. 3 shows a perspective environmental view of the ball and ring hitch lock reversibly hooked up to a ring type trailer hitch according to the invention. 
     FIG. 4 shows a perspective view of the ball and ring hitch lock illustrating an alternative location of a lock mechanism in the base plate according to the invention. 
     FIG. 5 shows a perspective view of the ball and ring hitch lock illustrating an alternative location of a sleeve in the base plate according to the invention. 
     FIG. 6 shows an elevated perspective view of the ball and ring hitch lock illustrating one embodiment of the lock mechanism according to the invention. 
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is a ball and ring hitch lock to prevent unauthorized control and use of an unhitched trailer with either a ball or ring type hitch. 
     Referring to the figures generally, the ball and ring hitch lock  600  comprises an upper plate  610  and a base plate  620 . The upper plate  610  comprises a lower surface  630  and a post  640  extending in a normal direction from the lower surface  630  of the upper plate  610 . The post  640  has a plurality of notches  650  defined therein. The notches  650  may take the form of serrations or any other equivalent form. The upper plate  610  and a base plate  620  are preferably made of steel, but any material that is sufficiently durable may be used. 
     The base plate  620  comprises an upper surface  660  and a sleeve  670  with a hollow bore  680 . In FIG. 1 the sleeve  670  extends in a normal direction through the base plate  620 . A side opening  690  is defined in a side of the sleeve  670 . The sleeve  670  is sized to accommodate the post  640 . The base plate further comprises a lock mechanism housing  770 . It will be understood that the sleeve  670  and the lock mechanism housing  770  may adopt various configurations. 
     The lock mechanism  700  has at least one catch  710  (see FIG.  6 ). The lock mechanism  700  has a locked position in which the at least one catch  710  extends into the side opening  690  of the sleeve  670  to engage at least one of the notches  650  defined in the post  640  in order to prevent removal of the base plate  620  from the post  640 . In the unlocked position the at least one catch  710  is retracted from the sleeve  670  in order to permit removal of the base plate  620  from the post  640 . 
     Still referring to the figures in general, the base plate  620  further comprises a male hitch anchor  720  which is attached to the upper surface  660  of the base plate  620 . The male hitch anchor  720  is sized to fit into a ring  750   a  or ball  750   b  type hitch. The male hitch anchor  720  can be of any suitable shape, e.g., the male hitch anchor  720  may have an hour glass shape as shown in FIG.  2 . The upper plate may comprise an optional guide rib  655  to facilitate docking a ring  740  type hitch  750   a  to the ball and ring hitch lock  600 . The invention includes other permutations that might be found in U.S. Provisional Patent Application Serial No. 60/363,272, filed Mar. 11, 2002. U.S. Provisional Patent Application Serial No. 60/363,272 is incorporated herein by reference in its entirety. 
     It is to be understood that the present invention covers any device having an upper plate  610  with a post  640  extending therefrom, such as a serrated or notched post, and a base plate  620  having a sleeve  670  adapted to accommodate the post  640  and a lock mechanism  700  adapted to reversibly engage the post  640  in the sleeve  670 , wherein the sleeve  670  aligns the post  640 , so that the lock mechanism  700  controls at least one catch  710  which engages the notches  650  or serrations to removably secure the upper plate  610  to the base plate  620  thereby enabling the device  600  to reversibly mate with a ball  750   b  or ring type hitch  750   a.    
     Preferably the base plate cannot be removed from the post  640  without inserting a key  705  in the lock and rotating a key stock cylinder  708  (see FIG.  6 ). Preferably the lock mechanism  700  is spring biased and the notches  650  defined in the post  640  are configured so that when the key  705  is moved into the locked position, the base plate  620  will slide down the post  640 , but is prevented from rising up the post  640 , after the fashion of a ratchet. 
     Referring to the figures in more detail, FIG. 1 shows an environmental perspective view of the ball and ring hitch lock  600  according to the invention. The hitch lock  600  is shown mated with a ring type hitch  750   a , i.e. a hitch with an eye or ring  740 . 
     FIG. 2 shows a perspective view of the two main parts of the ball and ring hitch lock  600  according to the invention, i.e. the upper plate  610  and the base plate  620 . It should be understood that the lock mechanism housing  770  can be attached to the lower surface  665  of the base plate  620 . Also, the sleeve  670  may extend from the lower surface  665  of the base plate  620  as shown in FIG.  5 . Thus, any suitable arrangement of the lock mechanism housing  770  and sleeve  670  will suffice providing that the lock mechanism  700  has a locked position in which the at least one catch  710  extends into the side opening  690  of the sleeve  670  to engage at least one of the notches  650  defined in the post  640  in order to prevent removal of the base plate  620  from the post  640 . 
     Referring to FIGS. 3 and 4, FIG. 3 shows a perspective environmental view of the ball and ring hitch lock  600  installed in an alternative method to a hitch with a ring  750   a . FIG. 4 shows an alternative embodiment of the invention wherein the lock mechanism housing  770  is attached to the lower surface  665  of the base plate  620 . 
     FIG. 5 shows yet another variation in the arrangement of the lock mechanism housing  770  and the sleeve  670 . The lock mechanism housing  770  is attached to the lower surface  665  of the base plate  620  while the sleeve  670  terminates at, and is flush with, the top surface  660  of the base plate  620 . 
     FIG. 6 shows an elevated perspective view of the base plate  620  with a cover  760  of the lock mechanism housing  770  removed exposing the key stock cylinder  708 . The cover  760  forms part of the lock mechanism housing  770 . The cover  760  is fastened to the lock mechanism housing  770  using fasteners such as security hex screws  780  and  790 . A twist motion by the key  705  causes a lock pin  800  to move at least one catch  690  into the sleeve  670  via a side opening  690  in the sleeve and thereby engage the notches  650  in the post  640 . A fastener such as a spring pin  810  attaches the lock pin  800  to the at least one catch  690 . 
     It will be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. In particular, it will be understood that the scope of the present invention extends to any lock mechanism having an upper plate with a post extending therefrom, such as a serrated or notched post, and a base plate having a sleeve adapted to accommodate the post and a lock mechanism adapted to reversibly engage the post in the sleeve, wherein the sleeve aligns the post, so that the lock mechanism controls a catch which engages the notches or serrations to removably secure the upper plate to the base plate thereby enabling the device to reversibly mate with a ring or ball hitch.