Abstract: A hydraulic system for lifts provided with two independently supported parallel platforms comprises at least two cylinder-piston units (80, 81) for raising the platforms, a metering device (7) for feeding identical quantities of fluid to said two units, and a balancing device (74, 75) operated by means (31, 32) for measuring the height difference between the platforms and arranged to feed a quantity of supplementary fluid to that cylinder-piston unit (80) or (81) operating the lower platform by withdrawing it from that cylinder-piston unit (81) or (80) operating the higher platform.

Abstract: A device for selecting the tools of the tool carrying head of tire removal machines in general comprises a hydraulic cylinder-piston unit (17) arranged to cause a tool carrying head (6, 7) to rotate, and connected in parallel with a hydraulic cylinder-piston unit (11) which causes a bar (1) on which the head (6, 7) is rotatably mounted to swivel in a vertical plane. A sequence valve (31) is provided in that pipe connecting together the cylinder-piston units (11), (17) through which the oil passes for moving the bar (1) into its rest position, and a free-wheeling linkage (20, 23, 24) is disposed between the bar (1) and head (6, 7) to enable the head (6, 7) to rotate in only one direction, and is associated with a positioning element (25) which fixes said head in position at every half revolution.

Abstract: Self-centering device for generally locking motor vehicle wheels on to balancing machine shafts, comprising a normal drive flange rigid with the threaded balancing shaft; a sleeve slip-mounted on the balancing shaft and from the central region of which there projects a flange, the opposing faces of which are provided with telescopic means for centering and locking the rim of a wheel to be balanced; and a collar mounted on the balancing shaft and provided with swivel means for axially engaging and disengaging the collar with and from the balancing shaft.