Provided is a diaphragm type actuator which drives an operation rod in an axial direction, including: a diaphragm which is connected to the operation rod; a high pressure chamber which is adjacent to one end side of the diaphragm in the axial direction; a low pressure chamber which is adjacent to the other end side of the diaphragm in the axial direction; and a return spring which is provided in the low pressure chamber and urges the diaphragm toward the high pressure chamber. Since an absorption portion is disposed inside the high pressure chamber, a force acting on the diaphragm is absorbed when the diaphragm moves toward the high pressure chamber and stops therein.

In a fluid pressure cylinder, cylindrical bodies are connected to both ends of a cylinder tube, and latching rings are disposed detachably in interior of the cylindrical bodies. A head cover and a rod cover, which are accommodated in the cylinder tube, are fixed by the latching rings. Recesses, which are recessed diametrally inward, are provided on outer circumferential surfaces of the head cover and the rod cover, respectively. First and second fluid ports open respectively in the recesses, and a pressure fluid is supplied and discharged through the first and second fluid ports.

A pressure-medium cylinder does not have a component that dynamically seals the piston rod and can be well-cleaned safely from outside. The pressure-medium cylinder includes a cylinder housing, a piston, a piston rod, and a static end-position seal. The piston is axially movably disposed in the cylinder housing. The piston rod is connected to the piston and penetrates the cylinder housing toward an end face through an outlet opening. The piston rod has a stop surface extending radially from the piston rod in a piston rod portion disposed outside of the cylinder housing. The stop surface contacts the cylinder housing in an end position during retracting of the piston rod and thus sealingly covers and/or extends around a gap region or gap regions between the piston rod and an edge of the outlet opening.

A bumper sized to fit a cylinder of a fastener driving tool includes a side profile of the bumper defined by a plurality of flat regions and a plurality of convex regions around an outer periphery of the bumper. Included in the bumper are an inner peripheral surface and an outer peripheral surface. The flat and convex regions are disposed on the outer peripheral surface of the bumper in an alternating pattern.

A fluid pressure cylinder which has a head cover and a rod cover provided on both ends of a cylinder tube, wherein the head cover and the rod cover are formed by casting such as die-casting. A first connecting channel which recesses in a groove shape in the outward radial direction is formed in the outer-circumferential surface of a first concave section of the head cover. A ring-shaped first holder is pressed into the first concave section, causing the formation of a cross-sectionally rectangular first connecting channel, the opening region of which is sealed. In addition, the first connecting channel connects a cylinder chamber of the cylinder tube and a first cushion chamber of the head cover.

A bumper sized to fit a cylinder of a fastener driving tool includes a side profile of the bumper defined by a plurality of flat regions and a plurality of convex regions around an outer periphery of the bumper. Included in the bumper are an inner peripheral surface and an outer peripheral surface. The flat and convex regions are disposed on the outer peripheral surface of the bumper in an alternating pattern.

A mechanism to reduce load of a hydraulic cylinder having a body, a stem movable within the body, and a piston rod connected to the stem. The mechanism includes a mechanism body attached to the body and defining a recess, and a retainer attached to the mechanism adjacent the opening of the recess so that the retainer substantially fills the opening of the recess, and having an aperture that receives an end of the piston rod. The mechanism further includes a cap attached to the piston rod of the hydraulic cylinder within the recess, the cap having a diameter greater than the diameter of the aperture in the retainer, and a spring connected to the cap at a first end and to the retainer at a second end so that as the piston rod moves relative to the failsafe mechanism body, to reduce load transfer between the piston rod and the cylinder body.

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.

An apparatus for actuating a valve includes a first actuator having a first actuator housing and second actuator with a second actuator housing. A first plate is positioned within the first actuator housing and a second plate is positioned within the second actuator housing. An intermediate stem extends from a first pressure chamber of the first actuator housing to the second plate. A pressure media path extends through the intermediate stem and a second seal nut that extends into the second plate, the pressure media path providing fluid communication between the first pressure chamber, and a second pressure chamber of the second actuator housing. An injection port is open into one of the first pressure chamber and the second pressure chamber. The first plate and the second plate are movable in response to pressure media injected into the injection port, for actuating the valve.

There are provided an actuator that can be reduced in weight as compared with a related art while alleviating an impact at an activation, a safety apparatus that ejects an ejected object, and an aerial vehicle including the safety apparatus. A safety apparatus 100 includes an actuator 1, a push-up member 15 that is pushed up in one direction by the actuator 1, an ejected object 16 that is pushed up while being supported by the push-up member 15, a bottomed cylindrical container 18, and a lid 21 that closes an opening end of the container 18. The actuator 1 includes a piston member 10, a cylinder 14 that accommodates the piston member 10 and is provided with a bore 13 through which the piston member 10 protrudes outward at the time of activation, a base 2 to which one end of the cylinder 14 is caulked and fixed and that is attached to a center of a bottom inside the container 18, and a gas generator 17 as a power source for moving the piston member 10 in the cylinder 14.