Horizontally and vertically movable fifth wheel for truck-tractors

Claim 1

A FIFTH WHEEL ASSEMBLY FOR A TRACTOR COMPRISING: A CARRIAGE HAVING FIRST AND SECOND LONGITUDINALLY SPACED PARALLEL AXLES EACH CARRYING A PAIR OF SPACED ROLLERS; SAID AXLES BEING MOUNTED AT RIGHT ANGLES TO THE LONGITUDINAL AXIS OF SAID TRAILER AND BEING MOUNTED FOR DISPLACEMENT LONGITUDINALLY OF SAID TRACTOR RELATIVE TO ONE ANOTHER; FIRST RAIL MEANS ADAPTED FOR CONNECTION TO THE FRAME OF SAID TRACTOR FOR SUPPORTING SAID ROLLERS AND GUIDING SAID CARRIAGE LONGITUDINALLY OF SAID TRACTOR; A THIRD AXLE MOUNTED ON SAID CARRIAGE INTERMEDIATE AND IN ELEVATED PARALLEL RELATION TO SAID FIRST AND SECOND AXLES AND CARRYING A PAIR OF SPACED ROLLERS ADAPTED FOR ROLLING MOVEMENT ON SAID TRACTOR FRAME; A PAIR OF FRAMES PIVOTALLY CONNECTED TO AND JOINING SAID FIRST AND THIRD AND SAID SECOND AND THIRD AXLES RESPECTIVELY FOR ELEVATING SAID FIFTH WHEEL UPON MOVEMENT OF SAID FIRST AND SECOND AXLES RELATIVELY CLOSER TO ONE ANOTHER; AND MEANS RELEASABLY CONNECTING SAID CARRIAGE TO SAID FIRST RAIL MEANS PERMITTING FREE ROLLING MOVEMENT OF SAID FIFTH WHEEL ASSEMBLY LONGITUDINALLY OF SAID TRACTOR.