A hydraulic machine unit that can be operated with various working forces, in which working medium is selectively delivered, via a pump-piston accumulator system, to a main cylinder and at least one driving cylinder, wherein at least for one working stroke a pump system of the pump-piston accumulator system is used to provide working medium to a piston accumulator of the pump-piston accumulator system, and then at least for the working stroke at least the main cylinder is charged with a working pressure from the piston accumulator, and wherein at least for a return stroke the at least one driving cylinder is charged with a return stroke pressure from the pump-piston accumulator system, can be of structurally simple configuration if, at reduced working forces, the working pressure is reduced with respect to the piston accumulator pressure prevailing in the piston accumulator.

A hydraulic machine unit that can be operated with various working forces, in which working medium is selectively delivered, via a pump-piston accumulator system, to a main cylinder and at least one driving cylinder, wherein at least for one working stroke a pump system of the pump-piston accumulator system is used to provide working medium to a piston accumulator of the pump-piston accumulator system, and then at least for the working stroke at least the main cylinder is charged with a working pressure from the piston accumulator, and wherein at least for a return stroke the at least one driving cylinder is charged with a return stroke pressure from the pump-piston accumulator system, can be of structurally simple configuration if, at reduced working forces, the working pressure is reduced with respect to the piston accumulator pressure prevailing in the piston accumulator.

A large-capacity bag-type constant-pressure accumulator comprises a shell and a bag placed in the shell, as well as a variable area piston, a floating piston, a piston, and a flange. On the piston rod of the variable area piston is mounted the floating piston, while at the bottom of the variable area piston rod is connected the piston. Additionally, through holes are provided on the central axes of the variable area piston and the piston; such holes are connected to the bag through an inflation valve and connected with a cover plate at the bottom. On the piston are arranged the check valves I and check valves II. The flange is connected to the inner wall of the shell bottom.

A large-capacity bag-type constant-pressure accumulator comprises a shell and a bag placed in the shell, as well as a variable area piston, a floating piston, a piston, and a flange. On the piston rod of the variable area piston is mounted the floating piston, while at the bottom of the variable area piston rod is connected the piston. Additionally, through holes are provided on the central axes of the variable area piston and the piston; such holes are connected to the bag through an inflation valve and connected with a cover plate at the bottom. On the piston are arranged the check valves I and check valves II. The flange is connected to the inner wall of the shell bottom.

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.

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.

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 invention relates to an auxiliary system for starting or restarting the flow of gelled fluid contained in a pipeline (12) wherein the system comprises: at least one relief tank (13) fluidly connected (11) to the pipeline (12), wherein at least one relief tank (13) is suitable for receiving fluid from the pipeline (12); and at least one pressurising element upstream of at least one tank, suitable for pressurising the fluid in the pipeline (12), Additionally, the invention also provides an auxiliary method for starting or restarting the flow of gelled fluid in a pipeline (12) comprising at least one tank fluidly connected (11) to the pipeline (12) and at least one pressurising element upstream of at least one tank, wherein the method comprises the step of, at the start of the process, the pressurising element increasing the pressure in the pipeline (12) and filling at least one tank at least partially with fluid coming from the pipeline (12).

The present invention relates to an auxiliary system for starting or restarting the flow of gelled fluid contained in a pipeline (12) wherein the system comprises: at least one relief tank (13) fluidly connected (11) to the pipeline (12), wherein at least one relief tank (13) is suitable for receiving fluid from the pipeline (12); and at least one pressurising element upstream of at least one tank, suitable for pressurising the fluid in the pipeline (12), Additionally, the invention also provides an auxiliary method for starting or restarting the flow of gelled fluid in a pipeline (12) comprising at least one tank fluidly connected (11) to the pipeline (12) and at least one pressurising element upstream of at least one tank, wherein the method comprises the step of, at the start of the process, the pressurising element increasing the pressure in the pipeline (12) and filling at least one tank at least partially with fluid coming from the pipeline (12).

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.