초록 ▼

A piston-and-cylinder type actuator, for use particularly in steplessly-variable-ratio transmission units of the toroidal race rolling friction type. In such units the actuator may serve to thrust the input and output members and their intermediate rollers into engagement, so that drive will be tran

A piston-and-cylinder type actuator, for use particularly in steplessly-variable-ratio transmission units of the toroidal race rolling friction type. In such units the actuator may serve to thrust the input and output members and their intermediate rollers into engagement, so that drive will be transmitted. According to the invention enhanced thrust is obtained by interposing auxiliary pistons (6, 7) in the space between the main piston (1) and the end (4) of the cylinder (2). One of pistons 6, 7 is linked to the main piston 1 and the other to cylinder 2, and they divide the said space into two pressurized zones (16, 18) with a vented zone between them. Where the actuator has to rotate about the cylinder axis, unwanted centrifugal forces generated within zones 16, 18 may be diminished by forming the vented zone so that a quantity of fluid may accumulate in it. Centrifugal forces develop within this fluid too, and the vented and pressurized zones are put into communication in such a way that the centrifugal forces within the two zones are opposed and tend to cancel each other out.

대표청구항 ▼

A fluid pressure operated actuator comprising a cylinder having a cylindrical portion and a cylinder end portion and a main piston movable axially, in sealing relation, within the cylinder characterized by the following features in combination: (a) a pair of auxiliary piston members received within

A fluid pressure operated actuator comprising a cylinder having a cylindrical portion and a cylinder end portion and a main piston movable axially, in sealing relation, within the cylinder characterized by the following features in combination: (a) a pair of auxiliary piston members received within said cylinder between said main piston and the cylinder end portion, (b) sealing means permitting limited passage of fluid past the edges of the auxiliary piston members, (c) a pressurized zone between a first member of said pair of auxiliary piston members and the cylinder end portion, (d) another pressurized zone between a second member of the pair of auxiliary piston members and said main piston, (e) a vented zone between the members of the pair of auxiliary piston members, (f) mechanical linkage means coupling, to the main piston, the member of the pair of auxiliary piston members which is nearest to the cylinder end portion, (g) mechanical linkage means coupling to the cylinder end portion, the member of the pair of auxiliary pistons which is nearest to the main piston, (h) duct means for the introduction of pressurized fluid into the pressurized zones of paragraphs (c) and (d), above, (i) an escape orifice through which fluid, accumulating in said vented zone, may escape.