is still connected to the gripping head release of the actuator cable from the head is accomplished by operating a standard hose connection as already described except that it is modified slightly second hose connection 70 has a central plug 72 with an annular groove 74 which seats retainer balls 76 which also engage in bores through fixed outer sleeve member 78 which extends from the plunger 66 an outer sleeve 80 having arms 82 extending to the sides of the head body 54 is pushed downwardly against the action of spring 84 which moves the keys 86 free of the retainer balls thus freeing the center plug a stop 88 is mounted to the sleeve 78 to define a limit of travel for the sleeve looking at the head as a whole it can be seen that by pulling the collar 58 in the opposite direction from the arms 82 both the hose couplings will be released freeing both the sleeve and the actuator cable this will enable the plug 72 to pass through the corridor 90 provided in the upper hose coupling so that the head is very easily released reconnection of the head or of a modified embodiment of the head requires the reverse of the above described release operation the body portion 54 of the head of the type shown in fig7 has three jaw elements 92 which are pivoted on pins 94 and are actuated by means of the plunger.