Truck trailer fifth wheel pin lock

A truck trailer fifth wheel pin lock for protecting a truck trailer from theft by obstructing the fifth wheel pin of the trailer to prevent coupling thereof to a tractor, said fifth wheel pin having a circumferential circular groove extending therearound, said truck trailer fifth wheel pin lock comprising

• a bowl-like housing, said housing having an open mouth;
• and
• locking means for selectively locking the housing substantially coaxially around the fifth wheel pin of a truck trailer thereby obstructing said fifth wheel pin and preventing coupling thereof to a tractor, said locking means comprising an annular guide member coaxially rotatably mounted on the housing at the open mouth thereof and having a plurality of slots formed therethrough, a plurality of locking members, each having spaced opposite first and second ends, pivotally mounted in the housing at the mouth thereof in equiangularly spaced relation in the area of the first end of each, each of said locking members having a pin extending therefrom through a corresponding one of the slots for guiding the second end of the locking member into locking engagement in the groove of the fifth wheel pin in one position of said guide member and for guiding the second end of the locking member out of locking engagement with the groove of the fifth wheel pin and free therefrom in another position of said guide member, spring means coupled to the housing and the guide member for urging the locking members into locking engagement when the guide member is rotated in a predetermined direction about its axis, and key-released latch means for securing said locking members in position in locking engagement.