Fifth wheel plate assembly

Claim 1

A FIFTH WHEEL PLATE ASSEMBLY FOR SUPPORTING AND HITCHING A TRAILER HAVING A KINGPIN DEPENDING FROM THE UNDERSIDE THEREOF, SAID FIFTH WHEEL PLATE ASSEMBLY COMPRISING A PLATE, A SUBSTANTIALLY CIRCULAR OPENING IN SAID PLATE, AN ENTRY SLOT COMMUNICATING WITH SAID CIRCULAR OPENING, A COUPLER JAW SUPPORTED FOR TURNING MOVEMENT WITHIN SAID CIRCULAR OPENING, SAID COUPLER JAW INCLUDING A USHAPED JAW OPENING WHICH IS NORMALLY DISPOSED TO BE ENGAGED BY THE KINGPIN ENTERING SAID CIRCULAR OPENING THROUGH SAID ENTRY SLOT IN A MANNER CAUSING SAID COUPLER JAW TO BE TURNED TO CLOSE OFF COMMUNICATION BETWEEN SAID CIRCULAR OPENING AND SAID ENTRY SLOT AND RETAIN THE KINGPIN CAPTURED WITHIN SAID OPENING, A LOCKING NOTCH FORMED ON THE PERIPHERY OF SAID COUPLER JAW, A LOCKING PLUNGER MOUNTED ON SAID PLATE FOR LENGTHWISE MOVEMENT INTO AND OUT OF SEATING ENGAGEMENT WITH SAID LOCKING NOTCH WHEN THE LATTER IS ALIGNED THEREWITH, RESILIENT MEANS BIASING SAID LOCKING PLUNGER INTO SEATING ENGAGEMENT WITH SAID LOCKING NOTCH, MEANS FOR RETRACTING SAID LOCKING PLUNGER FROM SEATING ENGAGEMENT WITHIN SAID LOCKING NOTCH, SAID RELEASING MEANS COMPRISING A HORIZONTAL MEMBER MOVABLE LENGTHWISE OF SAID PLATE AND HAVING ONE END PROJECTING OUTWARDLY OF SAID PLATE, A CAMMING MEMBER FIXED TO THE OTHER END OF SAID HORIZONTAL MOVABLE MEMBER, A CAM FOLLOWER ASSEMBLY MEANS, MEANS ROCKABLY MOUNTING SAID CAM FOLLOWER ASSEMBLY ON SAID PLATE, SAID CAM FOLLOWER ASSEMBLY INCLUDING MEANS FIXED TO SAID LOCKING PLUNGER AND MEANS SLIDABLY CONTACTING SAID CAMMING MEMBER, AND BEING OPERATIVE UPON INWARD LENGTHWISE ACTUATION OF SAID MOVABLY MOUNTED MEMBER TO BE ROCKED SO THAT SAID LOCKING PLUNGER IS WITHDRAWN FROM SAID LOCKING NOTCH.