An actuator includes a body and at least a first offset connection port that is connected to the body by a first duct projecting from the body. The first connection port is mechanically connected to the body at least by first and second struts. The first strut and the second strut extend from the first connection port, respectively, to a first segment of the body and to a second segment of the body that is axially spaced apart from the first segment.

An undercarriage includes such an actuator as its locking or unlocking actuator.

The invention relates to a hydraulic cylinder, for example for use with a hydraulic tool, which hydraulic tool is provided with a frame and an element which is movable with respect to the frame by means of the hydraulic cylinder. A hydraulic tool which is operated by means of a hydraulic cylinder as described above is known from, for example, European patent no. 0641618. This patent discloses a frame which is coupleable to a jib of an excavator or the like and to which an assembly of two jaws can be coupled. One of the jaws is pivotable with respect to the other jaw by means of a hydraulic adjusting cylinder (a double-acting piston/cylinder combination).

A cylinder propping system includes a sleeve and a locking member. The sleeve includes an outer wall that defines an inner cavity and a ledge. The inner cavity is sized to receive at least a portion of a cylinder assembly therein. A first end of the outer wall is configured to hingedly couple to one end of the cylinder assembly. The ledge is spaced apart from the first end. The locking member is sized to engage with the ledge, between the ledge and a cylinder housing of the cylinder assembly, to prevent movement of the cylinder housing in at least one direction along a central axis of the sleeve.

A hydrostatic cylinder with a gas pressure accumulator, which is preferably designed as a piston accumulator, and which is arranged concentrically on the outer circumference of the cylinder is disclosed. A gas pressure is produced via a constant pressure source and is limited or is essentially constant in the gas pressure accumulator and also a constant pressure medium pressure is independent of the degree of filling of the gas pressure accumulator.

A working cylinder has a cylinder tube, a first closure part, a second closure part and a piston unit. The first closure part is arranged on a first cylinder tube end, the second closure part is arranged on a second cylinder tube end to define a cylinder interior. The piston unit defines at least one working chamber in the cylinder interior. The piston unit slides through the first closure part. The first closure part is joined to the cylinder tube by a first peripheral laser ring weld seam and the second closure part is joined to the cylinder tube by a second peripheral laser ring weld seam. The laser ring weld seams each define a fluid-tight sealing plane. A method for producing the working cylinder is provided.

A working cylinder has a cylinder tube, a first closure part, a second closure part and a piston unit. The first closure part is arranged at a first cylinder tube end and the second closure part is arranged at a second cylinder tube end, the cylinder tube and the first and second closure parts define a cylinder interior. The piston unit defines at least one working chamber in the cylinder interior. The piston unit slidably passes through the first closure part. The first closure part us joined to the cylinder tube in a positive-locking manner by a first circumferential laser ring weld seam. The second closure part is joined to the cylinder tube in a positive-locking manner by a second circumferential laser ring weld seam, and each of the laser ring weld seams define a fluid-tight sealing plane. At least one of the closure parts has an axially opening that is a circumferential concave receiving contour in which the cylinder tube engages. The receiving contour radially overlaps the cylinder tube, and a ring weld seam inclination angle thereof is 110 to 160 degrees.

An actuation device for a human-powered vehicle comprises a base member, a movable member, and an actuator. The movable member is movably provided on the base member. The actuator is configured to be actuated by stimulation including at least one of electric stimulation and heat stimulation so as to move the movable member relative to the base member in a first direction by pulling the movable member.

This method of gas exchange for four-stroke piston internal combustion engine comprising gas exchange through an intake and an exhaust valves and includes gas exchange through a piston-controlled port in a cylinder sleeve: exhausting combustion products through the port at the end of the power stroke and at the beginning of the exhaust stroke, removal of exhaust gases from the port (from the space outside the port, outside the cylinder) and air supply to the port (supply into afore-mentioned space). As a result, the combustion products do not return to the cylinder through the port at the end of the intake stroke and at the beginning of the compression stroke. This effect is combined with air intaking into the cylinder through the port at the end of the intake stroke and at the beginning of the compression stroke.

A hydraulic power generating system includes a hydraulic motor, a bidirectional generator connected to the hydraulic motor, a hydraulic cylinder, first and second tubes, a piston structure having a piston and first and second links, and a power driving device connected to the first link. The piston divides the hydraulic cylinder into first and second chambers. The first and second links are connected to the piston and disposed through the first and second chambers, respectively. The first tube is communicated with the first chamber and the hydraulic motor. The second tube is communicated with the second chamber and the hydraulic motor. When the power driving device drives the piston toward the first chamber, hydraulic oil is pumped to the hydraulic motor for rotating the bidirectional generator. When the power driving device drives the piston toward the second chamber, the hydraulic oil is pumped to rotate the bidirectional generator reversely.

In a cushion mechanism of a gas cylinder, when the pressure of a gas in a first pressure chamber is less than or equal to a prescribed pressure, a valve body cuts off communication between the upstream side and downstream side of a discharge flow passage by mean of the biasing force of a spring member. In addition, when the pressure of the gas exceeds the prescribed pressure, the valve body is displaced to the downstream side of the discharge flow passage against the biasing force, thereby enabling communication between the upstream side and the downstream side of the discharge flow passage.