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.

Provided are a volume change compensation device capable of reducing a manufacturing burden with a simple configuration and a damper device including the volume change compensation device. A damper device 100 includes a rotary damper, and includes a volume change compensation device 140 in a shaft 121 of a rotor 120. The volume change compensation device 140 includes an inner cylinder piston 142 pressed by an inner cylinder piston pressing elastic body 145 in a body tube 141 communicating with a hydraulic fluid housing portion 103 of the damper device 100 through a connection path 141a. The inner cylinder piston 142 is formed in a bottomed cylindrical shape opening on a connection path 141a side. In the inner cylinder piston 142, an inner cylinder inner small piston 143 is pressed against a bottom portion 142b by a small piston pressing elastic body 144. An air hole 142c is formed at the bottom portion 142b of the inner cylinder piston 142. The inner cylinder inner small piston 143 slides in the inner cylinder piston 142 according to the amount of hydraulic fluid 150 in the inner cylinder piston 142.

An accumulator includes: a main cylindrical housing having a closed first axial end and a second axial end; a piston arranged in the main cylindrical housing and sealed to an inner surface of the main cylindrical housing, which piston is movable in an axial direction and provides with the main cylindrical housing and the closed first axial end of the main cylindrical housing a variable accumulating space; an urging device arranged between the piston and the second axial end of the main cylindrical housing for urging the piston towards the first axial end of the main cylindrical housing; a fluid supply opening arranged in the first axial end of the main cylindrical housing, which fluid supply opening is in fluid connection with the variable accumulating space; and a protective cylindrical housing having a first and a second axial end, the protective cylindrical housing being arranged concentrically.

The present disclosure relates to a miniature pressure compensating device (10), for balancing pressure fluctuations in a hydraulic system, comprising at least one shell (12), at least one hollow hydraulic cylinder (16), at least one reciprocating piston (26) and at least one non-return valve (NRV) (28). The hydraulic cylinder (16) comprises at least one dual charging valve port (22) for facilitating charging of both said compressible and incompressible fluid and at least one built-in two-tier sealing mechanism (24) comprising at least one metal-to-metal seal (24a) and at least one secondary seal (24b) to achieve effective isolation of the incompressible and compressible fluids. The present miniature pressure compensating device (10) has a volume below 13 cc.

An accumulator includes an accumulator housing defining a first end, a second end opposite to the first end, and a hollow chamber. The accumulator also includes a piston slidably disposed within the hollow chamber and adapted to displace between the first and second ends. The piston divides the hollow chamber into a gaseous chamber proximate to the first end of the accumulator housing and a hydraulic chamber proximate to the second end of the accumulator housing. Further, the piston defines a first side surface in communication with the gaseous chamber and a second side surface spaced apart from the first side surface. The second side surface is in communication with the hydraulic chamber. A cavity of the piston is in communication with the second side surface and extends from the second side surface towards the first side surface. The cavity is in fluid communication with the hydraulic chamber.

The invention relates to an underwater-based, depth-compensable accumulator system which is adapted to produce hydraulic power for underwater operations, and which consists of one or more gas-free accumulator units. An accumulator unit according to the invention has only one movable part, but interaction with a switching device enables switching between multiple modes so that an accumulator unit can be configured to generate a desired hydraulic pressure at any sea depth.

A device for maintaining a hydraulic supply of a utility vehicle includes a hydraulic pump, which is adjustable in terms of its delivery volume via a pressure control inlet, for feeding hydraulic fluid to a hydraulic circuit, a pressure accumulator that can be charged from the hydraulic circuit via a check valve, a pressure connection between the hydraulic circuit and the pressure control inlet of the hydraulic pump being producible via a sensor line by means of a charging valve, and a supply connection between the pressure accumulator and the hydraulic circuit being producible by means of a discharging valve, by virtue of the check valve being bypassed.

The present disclosure is an accumulator that has an oil chamber, a first piston separating a first gas chamber from the oil chamber, a second piston separating a second gas chamber from the oil chamber, and a compressible member positioned between the second piston and a stop. The compressible member is configured to dampen motion of the second piston towards the stop.

The invention relates to a hydraulic device for a hydraulic system (12). The hydraulic device includes a chamber arrangement including at least one high-pressure chamber for connection to a high-pressure side of the hydraulic system, and at least one low-pressure chamber for connection to a low-pressure side of the hydraulic system; and a movable member arranged to reciprocate at least partly inside the chamber arrangement in response to pressure variations within the at least one high-pressure chamber and within the at least one low-pressure chamber. The chamber arrangement further includes at least one tank chamber for connection to a tank-pressure side of the hydraulic system.

An accumulator system includes a chamber configured to receive a first fluid, a piston configured to move within the chamber to pressurize and drive the first fluid out of the chamber, a driving shaft coupled to the piston, a screw adapter coupled to the driving shaft, a plurality of anti-rotation shafts, and an electric actuator configured to couple to the screw adapter and to rotate the screw adapter to axially move the driving shaft. The piston includes a body defining a first aperture and a plurality of counterbores. The driving shaft is coupled to the piston via the first aperture. The piston is configured to slide over the plurality of anti-rotation shafts via the plurality of counterbores.