Double sliding door lock

Claim 1

IN A LOCK, APPARATUS COMPRISING: A HOUSING; A PLUNGER MEMBER MOUNTED FOR AXIAL SLIDING MOVEMENT BETWEEN A FIRST AXIAL POSITION AND A SECOND AXIAL POSITION IN SAID HOUSING; MEANS PREVENTING ROTATIONAL MOVEMENT OF SAID PLUNGER MEMBER; RELEASABLE CATCH MEANS AUTOMATICALLY ACTUATABLE WHEN SAID PLUNGER MEMBER IS MOVED TO SAID FIRST AXIAL POSITION, FOR LOCKING SAID PLUNGER MEMBER AT SAID FIRST AXIAL POSITION; A KEY-CONTROLLED LOCK MEMBER MOUNTED IN SAID PLUNGER MEMBER AND MOVABLE RELATIVE TO SAID PLUNGER MEMBER BY MEANS OF A KEY, SAID CATCH MEANS OPERATING INDEPENDENTLY OF THE LOCK MEMBER TO LOCK THE PLUNGER MEMBER; MEANS RESPONSIVE TO SUCH MOVEMENT OF SAID LOCK MEMBER AND INDEPENDENT OF THE KEY EXCEPT FOR MOVING THE LOCK MEMBER FOR RELEASING SAID CATCH MEANS TO UNLOCK SAID PLUNGER MEMBER FOR AXIAL MOVEMENT FROM SAID FIRST AXIAL POSITION TO SAID SECOND AXIAL POSITION; AND MEANS BIASING SAID LOCK MEMBER FOR RETURN MOVEMENT TO ITS ORIGINAL POSITION AFTER MOVEMENT BY THE KEY, WHEN THE KEY IS RELEASED.