Steering lock assembly

A steering lock which comprises, in combination:

• a lock housing including a cylinder block having an axial bore defined therein, said axial bore being constituted by first and second cavities axially aligned with each other, and a mounting block extending generally laterally outwardly from the cylindrical block and having a guide opening defined therein in communication with the first cavity;
• a locking member supported movably in said guide opening for locking and unlocking an automobile steering shaft;
• a cylinder lock plug operatively substantially housed in an axially non-movable fashion within the second cavity adjacent one end of the cylinder block and including a barrel, said barrel having an axially extending key groove defined therein for receiving a mating key, said barrel being rotatable through a predetermined angle between inoperative and operative positions about the longitudinal axis thereof only when the mating key inserted in said key groove is turned, said barrel including means for holding the barrel in the inoperative position in the absence of the mating key in the key groove, but for permitting the barrel to be rotatable after the insertion of the mating key in the key groove, said holding means having a capability of discriminating whether or not the mating key inserted in the key groove is correct and acceptable to the cylinder lock and accepting only the correct and acceptable key;
• means coupled with said locking member for driving said locking member and housed in the first cavity for movement between locked and unlocked positions to cause the locking member to lock and unlock the steering shaft, respectively, said driving means being moved from the locked position towards the unlocked position in response to the rotation of the barrel from the inoperative position towards the operative position and also moved from the unlocked position towards the locked position in response to the rotation of the barrel from the operative position towards the inoperative position;
• means operatively coupling said barrel and said driving means;
• means for biasing the driving means to assume the locked position;
• and
• a retaining mechanism for retaining the driving means in the unlocked position once the driving means has been moved to the unlocked position and so long as the mating key inserted in the key groove is left unremoved therefrom even though the barrel has subsequently been rotated from the operative position back to the inoperative position, but for releasing the driving means from the unlocked position to allow said driving means to move towards the locked position by the action of said biasing means upon withdrawal of the inserted key from the key groove, said retaining mechanism comprising a locking lever having a bearing pin extending from a substantially intermediate portion thereof in at least one direction perpendicular to the locking lever, said cylinder block having a bearing for said pin to which said pin has access from only said one end of said cylinder block said locking lever being displaceable to assume first, second and third operative positions, a biasing spring for urging the locking lever in one direction about the bearing pin, and means controllable by the mating key for permitting the locking lever to assume the first operative position during the absence of the mating key in the key groove and for causing the locking lever to assume any one of the second and third operative positions against the biasing spring depending on the position of the driving means during the presence of the mating key in the key groove, said locking lever being engaged with the driving means to lock the driving means in the unlocked position when in the second position and disengaged from the driving means when in any one of the first and third positions;
• said cylinder block having an elongated chamber defined therein and extending axially of the cylinder block in communication with the second cavity, said second cavity and said elongated chamber each having first and second open ends at the opposite ends of said second cavity with respect to each other which are open at annular end faces on the cylinder block opposite from the first cavity and towards the first cavity, respectively, said locking lever being displaceably held in position inside the elongated chamber by insertion through the first open end in a direction axially thereof along the longitudinal extent of the cylinder block.