member 104 pivotally connected about horizontal pivot 106 to vertical support member 102 a hitch head generally designated 108 is pivotally connected about horizontal pivot 110 to the extending end of vertical support member 102 hitch 100 is adapted to be pulled from a retracted position to an erect position by hook h on the rear of tractor m upon forward movement of the tractor bumper block b on the rear of tractor m is adapted to knock down hitch 100 to a retracted position from erect position upon rearward movement of tractor m and effect unlocking of the trailer kingpin p and unlocking of diagonal support member 104 to permit retracting of hitch 100 hitch head 108 has top plate 124 a lower plate 126 and a tapered opening 128 at its forward end through which the kingpin is received as the hitch is raised or as the trailer is moved rearwardly kingpin p strikes jaws 130 132 which are normally held open by torsion springs 134 136 and turns them to their closed positions around the kingpin as shown in fig1 yoke 138 is then moved rearwardly by stiff spring 140 until blocks 142 144 of the yoke engage the backs of jaws 130 132 as shown in fig1 jaws 130 132 are then locked closed and cannot turn to their open positions an operating bar not shown or the bumper b may be used to overcome the bias of spring 140 and allow the jaws to assume the open position for removal of the kingpin u s pat no 3 225 707 incorporated into the present application by this reference may be referred to for a more detailed description of this type.