Various embodiments include an actuator comprising: a drive element; a transmission section; an actuating element mechanically actively connected to the drive element through the transmission section; a reset spring exerting a closing force on the actuating element; and a coupling device providing a mechanically active connection between the reset spring and the transmission section. The coupling device is configured to be brought into a first coupling state and a second coupling state. With the coupling device in the first coupling state, the reset spring exerts the closing force on the actuating element in a first closing direction. With the coupling device in the second coupling state, the reset spring exerts the closing force on the actuating element in a second closing direction. The first closing direction and the second closing direction are different.

A pistonless double-acting cylinder apparatus comprises a piston rod member, a first cylinder member disposed on the piston rod member, a second cylinder member disposed on an end surface of the first cylinder member, a tie rod which connects the first cylinder member and the second cylinder member, nuts provided on both ends of the tie rod, a first sealing ring located between the first cylinder member and the second cylinder member, a first cushion and a second cushion disposed on the piston rod member. The piston rod member comprises a piston rod left section, a first sealing gasket disposed on the piston rod left section, a piston rod middle section disposed on an end surface of the first sealing gasket, a second sealing gasket disposed on an end surface of the piston rod middle section, a piston rod right section disposed on the second sealing gasket.

A screw-threaded working cylinder includes a tubular cylinder that an end region. The end region has a first thread. The end region has a tapered wall section and the tapered wall section has an axial annular surface. A closure has a second thread and the closure is screwed by the second thread into the first thread in a final mounting position. The closure has a mating axial annular surface. The axial annular surface and the mating axial annular surface are pressed in a positive fitting contact to one another in the final mounting position for defining a pressure contact surface. The pressure contact surface defines a sealing plane, and a surface pressure in an area of the pressure contact surface that causes a deformation of the tubular cylinder and the closure. The deformation occurs within an elastic limit over a range from zero applied pressure to a maximum permissible pressure by a pressure medium for the working cylinder. A piston unit is accommodated in the tubular cylinder.

Retention systems for retaining a gland is provided. A hydraulic actuator may comprise a cylinder closed at an end by a gland, wherein the gland comprises a gland body having a bearing flange disposed within an interior volume of the cylinder, a lock ring retainer disposed between the gland body and the cylinder and contacted with the bearing flange, and a lock ring coupled between the lock ring retainer and a lock ring channel of the cylinder.

The present invention provides a seal housing (102) for releasable attachment to a hydraulic or pneumatic cylinder (101), the seal housing (102) being suitable for retaining a seal assembly and the seal housing (102) comprising a generally annular main body (201). The annular main body (201) defines an annular disc-shaped portion (202) having an upper surface (203), a lower surface (204), an outer peripheral edge (205) and an inner edge (206). Said inner edge (206) bounds a circular opening (207) extending the full height of said annular disc shaped portion (202) between said upper and lower surfaces (203, 204). The annular main body (201) further defines an annular collar portion (208) upstanding from the upper surface (203) of said disc shaped portion (202) adjacent said peripheral edge (205) of said disc shaped portion (202), said annular collar portion (208) extending height-wise from a base end (209) joined to said disc-shaped portion (202) to an upper end (210), and width-wise from an inner edge (211) to an outer peripheral edge (212), said inner edge (211) of said annular collar portion (208) bounding a circular opening (213) extending the full height of said annular collar portion (208). The annular main body (201) also further defines an annular flange portion (216) extending height-wise downwardly from the lower surface (204) of said disc-shaped portion (202) from a base end (217) joined to said lower surface (204) of said disc-shaped portion (202) to a distal end (218), and width wise from an inner edge (219) to an outer edge (220).

The invention relates to a hydraulic cylinder comprising a body (1) having a wall (3) that defines a cylindrical cavity (2), with a cylindrical cavity axis (X), in which a piston (4) is movably mounted, said piston (4) separating said cylindrical cavity (2) into two tight chambers (5, 6) that are isolated from each other, the wall (3) of the body comprising at least two passages (7, 8) for introducing or discharging a fluid into each of said two chambers (5, 6). The cylinder also comprises two end walls (17, 18) and a rigid rod (32) which is secured to the piston (4) and coaxial with the cylindrical cavity (2), said rod (32) passing through a passage opening (20) provided in one of the two end walls (17, 18). The cylinder is characterised in that it comprises a position sensor (38) comprising a sensor head (39), a sensor rod (40) which is secured to the sensor head (39) and around which a magnet (41) is fitted, and a connector (42) connected to said sensor head (39).

A screw-threaded working cylinder includes a tubular cylinder that an end region. The end region has a first thread. The end region has a tapered wall section and the tapered wall section has an axial annular surface. A closure has a second thread and the closure is screwed by the second thread into the first thread in a final mounting position. The closure has a mating axial annular surface. The axial annular surface and the mating axial annular surface are pressed in a positive fitting contact to one another in the final mounting position for defining a pressure contact surface. The pressure contact surface defines a sealing plane, and a surface pressure in an area of the pressure contact surface that causes a deformation of the tubular cylinder and the closure. The deformation occurs within an elastic limit over a range from zero applied pressure to a maximum permissible pressure by a pressure medium for the working cylinder. A piston unit is accommodated in the tubular cylinder.

Various embodiments include an actuator comprising: a drive element; a transmission section; an actuating element mechanically actively connected to the drive element through the transmission section; a reset spring exerting a closing force on the actuating element; and a coupling device providing a mechanically active connection between the reset spring and the transmission section. The coupling device is configured to be brought into a first coupling state and a second coupling state. With the coupling device in the first coupling state, the reset spring exerts the closing force on the actuating element in a first closing direction. With the coupling device in the second coupling state, the reset spring exerts the closing force on the actuating element in a second closing direction. The first closing direction and the second closing direction are different.

A linear actuator comprising a housing, a top plate securable to the housing at a first end, and a bonnet securable to the housing at a second end. The housing, top plate and bonnet form a sealed cavity, a piston is biased away from the bonnet and a stem is secured to the piston, wherein the stem is axially actuated by motion of the piston and the stem passes through the bonnet to be securable to an actuated component. Further, the actuator can be disassembled and serviced while still attached to actuated equipment.

A head end seal assembly for a hydraulic cylinder may include a cylinder seal carrier having a seal carrier bore with a main seal groove and a coating ring groove adjacent the main seal groove. A main seal disposed within the main seal groove is fabricated from a resilient material and engages a rod outer surface of a rod to substantially prevent leakage of pressurized fluid from the hydraulic cylinder. A coating ring disposed within the coating ring groove is fabricated from a thermoplastic polymer such as Teflon and engages the rod outer surface such that portions of the thermoplastic polymer are deposited into indentations on the rod outer surface as the rod slides past the coating ring to smooth the surface and reduce abrasion between the rod and the main seal. A second coating ring on the opposite side of the main seal may coat the rod as it moves in the opposite direction.