A flow rate controller and a drive device are provided with a cylinder flow passage connected to an air cylinder; a main flow passage for supplying air to and discharging air from the air cylinder; an auxiliary flow passage that has a first throttle valve and through which exhaust air discharged from the air cylinder passes with a smaller flow rate than that of the main flow passage; a switch valve that switches between a first position in which the cylinder flow passage communicates with the main flow passage and a second position in which the cylinder flow passage communicates with the auxiliary flow passage; and a pilot air adjustment part that guides a portion of the exhaust air from the air cylinder as pilot air to the switch valve.

A valve actuator device includes a supporting body, a driving shaft, and a fluid cylinder having a body connected to one side of the supporting body. The cylinder has a rod that controls rotation of a driving arm rigidly connected to the driving shaft. Linear movement of the rod is converted into rotation of the driving arm by engagement of a cam-follower pin carried by the rod within a slot formed in the driving arm. The slot is formed in an insert that constitutes an element separate from the driving arm body and that is received and held within a seat of the driving arm body. Thus, a single main body for the driving arm is provided, having a plurality of inserts for selective mounting within the seat and are differentiated from one another in the dimensions and shape of the slot and/or in the material of the insert.

A fluid pressure cylinder. A first stepped section having a greater diameter than a cylinder chamber is formed at one end of a cylinder tube constituting a fluid pressure cylinder. A disc-shaped head cover is inserted into the cylinder chamber. The one end is pressed and plastically deformed by a staking jig to form a deformed section, and the head cover is affixed within the first stepped section by the deformed section. As a result of this configuration, the head cover can be more firmly affixed while the sealing effect between the cylinder tube and the head cover is ensured. This eliminates need for a seal means and an engagement means which is used to affix the head cover, and consequently, the number of parts can be reduced.

A hydraulic cylinder includes: a cylinder tube; a piston; a piston rod; a pair of end covers; and a snubbing mechanism configured to reduce the moving speed of the piston after the piston reaches the vicinity of the end of its stroke. The snubbing mechanism includes: a supply/discharge port formed in an associated one of the end covers; a valve configured to open and close the supply/discharge port; a connector configured to connect the valve and the piston together; and at least one recess extending from the edge of the supply/discharge port. When the piston approaches the end of its stroke, the valve closes the supply/discharge port to form a throttle oil passage, and hydraulic oil is discharged through the throttle oil passage to reduce the moving speed of the piston.

A hydraulic assembly includes a barrel having a head port disposed proximate an end of the barrel, a piston assembly disposed within the barrel and movable relative thereto, the piston assembly including a bore terminating at a back wall, the bore defining a longitudinal axis, and a plunger at least partially received within the bore and translatable along the longitudinal axis. The plunger includes a main body having an end facing the head port, a shoulder extending radially-outwardly from the main body, and a passageway extending through the main body. A spring is disposed in a first region defined between the shoulder and the back wall, the spring configured to exert a biasing force on the shoulder.

An actuator is disclosed comprising: a moveable member; a first hydraulic chamber in contact with a first surface of the moveable member; a second hydraulic chamber in contact with a second, opposing surface of the moveable member; a movable locking mechanism coupled to a moveable wall of the second hydraulic chamber; and a resilient biasing member acting on the moveable wall of the second hydraulic chamber so as to bias the moveable wall and locking mechanism. The actuator is configured to selectively vary the pressure in the second hydraulic chamber so that the resilient biasing member is able to bias the moveable wall to move, thereby moving the locking mechanism to engage the moveable member so as to prevent the movement of the moveable member towards at least one of the first and second hydraulic chambers.

A hood lifting actuator according to various implementations includes a piston, a locking ring, and a housing including a protrusion. The housing further includes a distal end, the distal end defining a distal end wall, wherein the locking ring is retained between the distal end wall and the protrusion prior to actuation of the actuator. The piston travels from a retracted position to an extended position. In the extended position, the hood lifting actuator lifts a portion of a vehicle hood into an elevated position. In response to a force urging the piston from the extended position toward the retracted position, such as a person impacting the portion of the vehicle hood, the locking ring engages the protrusion and the piston, thereby locking the piston in a locked position.

A pneumatic device includes a cylinder, a buffer member and a piston unit. The cylinder includes a cylinder wall defining an air chamber. The buffer member has a tubular wall that defines a communicating hole. The tubular wall has a length greater than the wall thickness thereof. The piston unit includes a sealing member, and a rod member movably extending through the communicating hole. The rod member has a driven section received within the air chamber and mounted with the sealing member. The piston unit is movable between a restoring position where the driven section is spaced apart from the buffer member, and an impact position where at least one of the driven section and the sealing member is in contact with the buffer member.

The invention relates to a hydraulically actuated piston (9) guided in a cylinder (8), and to a hydraulic working tool (1) having a working head (2), wherein the piston (9) has an impact surface (15) which borders an impact space (16) on the piston side provided between the piston (9) and the cylinder (8), and wherein hydraulic fluid (17) can act on the impact surface (15) by increasing the impact space (16) in order to move the piston (9) in an impact direction (r), and the piston (9) forms a limiting device (25) for a through-flow of the hydraulic fluid (17). According to the invention, in order to design a hydraulic piston guided in a cylinder or a hydraulic working tool in such a way that no undue signs of wear occur even during working processes with the sudden disappearance of the counter pressure, a hydraulic chamber (19) filled with the hydraulic fluid (17) is formed in the impact direction (r) after the limiting device (25), wherein a volume of the hydraulic chamber (19) is reduced according to the increase in the impact space (16), by means of the displacement of hydraulic fluid (17) out of the hydraulic chamber (19) and into the impact space (16) via the limiting device (25).

On inner wall surfaces of a head cover and a rod cover of a fluid pressure cylinder, respective pluralities of first and second spigot pins are installed to project out from the inner wall surfaces. The first and second spigot pins are disposed on circumferences of a predetermined diameter that internally contact or inscribe the cylinder tube. Further, when the cylinder tube is assembled with respect to the head cover and the rod cover, by the flange members of the first and second spigot pins inscribing the inner circumferential surface thereof, the cylinder tube is positioned and assembled coaxially with respect to the centers of the head cover and the rod cover.