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 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 telescopic device having a housing and a rod is slidably mounted within a bore of the housing. First and second bearings provide sliding engagement between the rod and the housing. The first bearing is mounted relatively close to the open end of the bore and the second bearing is mounted relatively far from the open end of the bore relative to the first bearing. The second bearing is annular in shape with a central axis, the bearing has a radially outer mounting surface of arcuate cross-section and a radially inner bearing surface for sliding engagement with an outer surface of the rod and wherein the inner sidewall is provided with an annular groove having a second mounting surface of arcuate cross-section to house and retain the second bearing.

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.

A hydraulic cylinder may include a cylindrical tube, a piston head with a piston rod disposed within the cylindrical tube, a cylinder head secured in one tube end of the cylindrical tuba and having the piston rod extending through a piston rod opening, and a cylinder cap with a cap sealing portion inserted in the opposite tube end of the cylindrical tube. The tube end is crimped down onto the cap sealing portion so that a tube material of the cylindrical tube is disposed within the plurality of annular cap grooves in the cap seal portion to retain the cylinder cap. The cylinder head may have a similar plurality of annular head grooves, with the corresponding tube end being crimped down onto the cylinder head.

A hydraulic cylinder may include a cylindrical tube, a piston head with a piston rod disposed within the cylindrical tube, a cylinder head secured in one tube end of the cylindrical tuba and having the piston rod extending through a piston rod opening, and a cylinder cap with a cap sealing portion inserted in the opposite tube end of the cylindrical tube. The tube end is crimped down onto the cap sealing portion so that a tube material of the cylindrical tube is disposed within the plurality of annular cap grooves in the cap seal portion to retain the cylinder cap. The cylinder head may have a similar plurality of annular head grooves, with the corresponding tube end being crimped down onto the cylinder head.

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.

Passenger restraint systems are provided. The restraint systems can include: a passenger seat supported by a frame; a restraint bar pivotably attached to the frame; and at least one piston operably engaged between the restraint bar and the frame. Restraint system pistons are provided. The pistons can include: a central chamber housing a piston head and rod; a fluid reservoir in fluid communication with the central chamber; and at least one electromechanical valve operable between an open and a closed position. Methods for restraining a passenger within a seat are also provided.

Passenger restraint systems are provided. The restraint systems can include: a passenger seat supported by a frame; a restraint bar pivotably attached to the frame; and at least one piston operably engaged between the restraint bar and the frame. Restraint system pistons are provided. The pistons can include: a central chamber housing a piston head and rod; a fluid reservoir in fluid communication with the central chamber; and at least one electromechanical valve operable between an open and a closed position. Methods for restraining a passenger within a seat are also provided.

A modular electrohydraulic actuator including an electric motor, a hydraulic pump driven by the electric motor, and a hydraulic actuator in fluid communication with the hydraulic pump. The hydraulic actuator includes a hydraulic cylinder supporting a pressure sleeve in which a piston and rod is adapted for reciprocating motion in response to a supply of pressurized fluid to a first side or a second side of the piston, wherein at least one of the electric motor, hydraulic pump, hydraulic cylinder, piston, piston rod or the pressure sleeve supported in the hydraulic cylinder is selectively removable and replaceable with a different component to vary at least one performance characteristic of the electrohydraulic actuator.