Device for selecting the tools of the tool carrying head of tire removal machines in general

In a tire changing machine of the type in which a tool carrying head is mounted on a bar which can swivel under the action of a first double-acting hydraulic cylinder-piston unit between a working position close to the tire and a rest position remote from the tire, and in which the tool carrying head is mounted to pivot so that different tools on the head can be pivoted to an operating position, the improvement comprising, a pinion gear rotatable supported by the bar, a rack engaging said pinion, a second double-acting cylinder-piston connected to said rack for reciprocating the rack to alternately rotate the pinion in a forward direction and a reverse direction, a free-wheeling one way drive between said pinion and the tool carrying head for rotating said head only when the pinion is rotated in said first direction, cooperating means between said head and said bar for retaining the head at each one-half revolution thereof, and wherein, said second double-acting hydraulic cylinder-piston unit is connected to the hydraulic line which supplies pressurized fluid to the first double-acting hydraulic cylinder-piston unit to swivel the head to the rest position, by a hydraulic sequence valve to direct fluid to the second cylinder and rotate said head, after the head is moved to the rest position by the first cylinder.