Collapsible support

Claim 1

A FIFTH WHEEL AND STAND ADAPTED TO ENGAGE A KINGPIN OF A TRAILER OR THE LIKE COMPRISING, A SUPPORT STRUCTURE MOVABLE BETWEEN A COLLAPSED INOPERATIVE POSITION AND A RAISED OPERATIVE POSITION, SAID SUPPORT STRUCTURE WHEN IN RAISED POSITION HAVING A GENERALLY VERTICAL SUPPORT MEMBER AND A DIAGONAL SUPPORT MEMBER CONNECTED TO THE VERTICAL MEMBER ON THE REARWARD SIDE THEREOF ADJACENT THE TRAILER OR THE LIKE, A SUPPORTING PLATE STRUCTURE CARRIED BY AND MOUNTED ON THE EXTENDING END OF SAID VERTICAL SUPPORT MEMBER FOR RELATIVE PIVOTAL MOVEMENT IN A VERTICAL PLANE, SAID SUPPORTING PLATE STRUCTURE COMPRISING A PAIR OF SPACED GENERALLY PARALLEL HORIZONTALLY EXTENDING PLATES WITH THE UPPER PLATE HAVING A FORWARDLY FACING OPENING THEREIN ADAPTED TO RECEIVE THE KINGPIN, A PAIR OF OPPOSITELY FACING JAWS BETWEEN SAID PLATES ADJACENT THE OPENING AND PIVOTED FOR MOVEMENT ABOUT VERTICAL AXES BETWEEN OPEN AND CLOSED POSITIONS WITH RESPECT TO THE KINGPIN, A LOCKING MEMBER BETWEEN THE PARALLEL PLATES BEING SUPPORTED BY THE LOWER PLATE AND HAVING A PAIR OF SPACED YOKE ARMS EXTENDING IN A FORWARD DIRECTION, ONE OF SAID ARMS EXTENDING ALONGSIDE THE OUTER SIDE OF ONE JAW AND THE OTHER ARM EXTENDING ALONGSIDE THE OUTER SIDE OF THE OTHER JAW, EACH OF SAID ARMS BEING FORMED ADJACENT ITS EXTENDING END WITH A HOOK PORTION TO ENGAGE AND LOCK THE ADJACENT JAW IN CLOSED POSITION ABOUT THE KINGPIN OF A TRAILER, SEPARATE MEANS FOR EACH JAW TO BIAS THE RESPECTIVE JAW CONTINUOUSLY TO OPEN POSITION, MEANS TO BIAS THE LOCKING MEMBER CONTINUOUSLY IN A REARWARD DIRECTION WITH SAID HOOK PORTIONS CONTINUOUSLY ENGAGING SAID JAWS, SAID JAWS