Trailer hitch lock

Claim 2

In an anti-theft device for guarding against unauthorized towing of a trailer by obstructing entry into the downwardly opening socket on the coupler of the trailer, said anti-theft device being of the type wherein a cover member readily attachable to the coupler is movable to an operative position thereon in which it blocks entry into the mouth of the socket, improved locking means for securing the cover member against displacement from its operative position, comprising: A. motion blocking means on the cover member positioned to enter the socket and, by engagement with a surface fixed with respect to the socket, prevent movement of the cover member out of its operative position; B. a cavity in the cover member adjacent to said motion blocking means; C. a lock body movable to and from an operative position in said cavity, in which position the lock body itself prevents movement of said motion blocking menans to a position clear of said surface; and D. key controlled means in the lock body for securing the lock body in its operative position.

Claim 3

The improvement set forth in claim 1, wherein said motion blocking means is an abutment on the cover member so situated thereon that the portion of the cover membr on which said abutment is located must be moved downwardly with respect to the socket to allow movement of the cover member out of its operative position, and wherein the lock body when in its operative position has a part thereof overlying a flange on the coupler, to prevent downward movement of said portion of the cover member.

Claim 4

The improvement set forth in claim 1, wherein said motion blocking means is an abutment projecting from the cover member to enter the socket and by its presence therein prevent movement of the cover member out of its operative position, withdrawal of said abutment from the socket requiring downward movement with respect to the coupler of that part of the cover member on which the abutment is located; and wherein the presence of the lock body in said cavity prevents such downward movement.

Claim 5

The improvement set forth in claim 3, wherein said cavity in the cover member has an open side facing said abutment, and wherein the lock body in its operative position protrudes through said open side of the cavity towards said abutment and overlies a part on the coupler fixed with respect to the socket to prevent downward movement with respect to the coupler of that part of the cover member on which the abutment is located.

Claim 6

The improvement set forth in claim 1, further characterized in that said means by which the presence of the lock body in its operative position in said cavity prevents movement of the cover member out of its operative position comprises: a lever pivotally connected with the cover member to swing to and from an operative position in which a portion thereof protrudes into the socket to prevent movement of the cover member out of its operative position, said lever also having a part thereof positioned to enter said cavity in the cover member and which part must enter said cavity for the lever to move out of its operative position; and wherein the presence of the lock body in its operative position in said cavity blocks entry of said part of the lever into said cavity.

Claim 7

The improvement set forth in claim 5, wherein said portion of the lever which protrudes into the socket to prevent movement of the cover member out of its operative position is the free end of the lever; wherein said free end of the lever abuts the adjacent surface of the socket in preventing movement of the cover member out of its operative position; wherein movement of the cover member out of its operative position can take place in only one direction; wherein the axis of the pivot about which the lever swings is transverse to said direction; and further characterized by means for adjusting the location of the axis about which the lever swings, to thereby shift the free end of the lever towards or from said surface of the socket which it abuts.

Claim 8

The improvement set forth in claim 6 wherein the means for adjusting the location of the lever pivot axis comprises an eccentric pivot pin securable in an adjusted position.

Claim 9

The improvement set forth in claim 5, wherein the cover member is formed with an elongated slot opening to the face thereof which is subjacent to the downwardly opening mouth of the sOcket when the cover member is in its operative position, said slot transversely intersecting said cavity and having an open end adjacent to the cavity; the lever being located in said slot and having its free end portion projecting through the open end thereof to provide a handle by which the lever may be moved to its operative position projecting above said face of the cover member; and wherein the lock body is that of a padlock having a U-shaped hasp, one leg of which constitutes the locking leg of the hasp, the hasp being received in the closed inner portion of said cavity with its legs projecting towards the mouth of the cavity to provide for securement of the locking leg of the hasp to the lock body when the latter is pushed farther into the cavity to its operative position, in which position only a part of the lock body projects into said slot to block movement of said lever out of its operative position so that upon key actuated release of the lock body from the locking leg of the hasp a relatively short movement of the lock body towards the open end of the cavity frees the lever for movement out of its operative position; and wherein retaining means fixed in the cover member and straddled by the legs of the hasp keeps the padlock assembled with the cover member.

Claim 10

The improvement set forth in claim 5, wherein the cover member has a slot opening to the face of the cover member which is subjacent to the downwardly facing mouth of the socket when the cover member is in its operative position, said slot also opening to said cavity in the cover member; the pivot axis about which the lever rocks being above the cavity, and the lever having an inner hooked end which in the operative position of the lever projects into the socket to engage a wall thereof to prevent movement of the cover member out of its operative position, and having an outer handle forming portion projecting from the slot to provide for movement of the lever to its operative position; and wherein the lock body when seated in said recess engages the lever and secures it against rocking out of its operative position.

Claim 11

The improvement set forth in claim 1, wherein said motion blocking means is a movable rigid member constrained to up and down movement with respect to the cover member; wherein said rigid member is yieldingly urged upward to a position in which a portion thereof engages the lip of the socket; and wherein said portion of the rigid member is shaped to have wedging engagement with the lip of the socket.

Claim 12

The improvement set forth in claim 10 wherein said movable rigid member is a round plunger slidably mounted in a bore in the cover member; and wherein the upper end portion of said plunger is connical to provide for said wedging engagement.

Claim 13

The improvement set forth in claim 1, wherein said motion blocking means is a pair of pivoted levers having a common pivot axis, and a spring reacting therebetween to yieldingly urge them apart; means on one of said members by which it may be moved to an active position in which said spring projects the other lever into the socket of the trailer coupler; and a curved cam surface on said other lever to engage the lip of the socket with a wedging action.

Claim 14

The improvement set forth in claim 11, wherein the plunger is slidably mounted on a stem which in turn is slidably received in a bore in the cover member and has an end portion projecting from the bottom of the cover member to provide a handle by which the plunger can be raised and lowered; wherein a spring confined between abutments on the plunger and said stem yieldingly urges the plunger upward with respect to said stem; and wherein the lock body in its operative position has a part thereof engaged by a surface fixed with respect to said stem when the stem is in its lifted position, whereby the stem is held in its lifted position holding the plunger through said spring in engagement with the lip of the socket.

Claim 15

The improvement set forth in claim 1, wherein said motioN blocking means includes an arm projecting upwardly from a rod that is slidably mounted in the cover member for fore and aft movement, to and from an operative position contiguous to the front edge of the lip of the socket; wherein a slot that opens through the top of the cover member receives said arm and guides its motion to and from its operative position; and wherein said blocking means has a surface accessible from said cavity in which the lock body is received, so that the lock body in said cavity can engage said surface and thereby prevent mount of said blocking means out of its operative position.

Claim 16

The improvement set forth in claim 14 wherein said surface of the blocking means is on a downwardly projecting foot on said rod, which foot is received in the bottom portion of said slot; and wherein said cavity in which the lock body is received opens to the bottom portion of said slot below said rod, so that the lock body in said cavity is in position to have the downwardly projecting foot abut the lock body and thereby restrain said arm against movement out of its operative position.

Claim 17

The improvement set forth in claim 14, wherein said slot opens to a laterally extending cavity in the cover member into which said arm may be lowered when the rod is retracted and in its retracted position is rotated.