A hydraulic cylinder (1) which acts as a cylinder hollow rod in an outer hydraulic cylinder (10) is disclosed comprising an inner rod (4) with a piston (2) and piston-gland (3) wherein the cylinder hollow rod (1) is held longitudinally displaceably in the cylinder housing (10). The system additionally has a cylinder base (5) and a fibre cover (14) on the outer casing of hydraulic cylinder (10). The system also has ports for fluid (11, 12 and 13) corresponding to four chambers, (67, 8 and 9 respectively). According to the invention, when pressure is applied to chamber (7), the internal rod (4) extends into the chamber (6), displacing its mass and dramatically increases the pressure in Chamber (6). This displacement is effectively an internal pump which can be activated multiple times within a given stroke of rod (1).

A linear actuator system includes a linear actuator including an outer body, an inner body disposed within the outer body, a fluid chamber at least partially extending between the inner body and the outer body, a piston chamber extending at least partially within the inner body, a valve configured to selectively fluidly couple the fluid chamber and the piston chamber to each other, a piston assembly including a piston, a variable volume within the piston chamber that extends between the piston and the valve, and a gas collector assembly including a fluid passageway. The piston assembly is disposed within the piston chamber, wherein a movement of the piston assembly causes a gas separated from a liquid within the variable volume to flow through the fluid passageway, through the valve, and into the fluid chamber.

A linear actuator system includes a linear actuator including an outer body, an inner body disposed within the outer body, a fluid chamber at least partially extending between the inner body and the outer body, a piston chamber extending at least partially within the inner body, a valve configured to selectively fluidly couple the fluid chamber and the piston chamber to each other, a piston assembly including a piston, a variable volume within the piston chamber that extends between the piston and the valve, and a gas collector assembly including a fluid passageway. The piston assembly is disposed within the piston chamber, wherein a movement of the piston assembly causes a gas separated from a liquid within the variable volume to flow through the fluid passageway, through the valve, and into the fluid chamber.

A collar for a telescopic cylinder with a cap includes the terminal portion of the cap that presents the opening of the cap, such that the collar includes in the following order a first annular element with a contoured profile, which surrounds the terminal portion and is welded thereto, and a second annular element, which can move with respect to the terminal portion and to the first annular element. The collar further includes an O-ring, made of rubber, surrounding the terminal portion and a third annular element surrounding the terminal portion and welded thereto. The first annular element has, at its internal circumference, an annular guide with a curved internal circumferential surface, the internal circumferential surface having, at each point of its circumference, a vertical cross-section with a shape that is concave as it progresses toward the outside of the collar.

A collar for a telescopic cylinder with a cap includes the terminal portion of the cap that presents the opening of the cap, such that the collar includes in the following order a first annular element with a contoured profile, which surrounds the terminal portion and is welded thereto, and a second annular element, which can move with respect to the terminal portion and to the first annular element. The collar further includes an O-ring, made of rubber, surrounding the terminal portion and a third annular element surrounding the terminal portion and welded thereto. The first annular element has, at its internal circumference, an annular guide with a curved internal circumferential surface, the internal circumferential surface having, at each point of its circumference, a vertical cross-section with a shape that is concave as it progresses toward the outside of the collar.

A hydraulic actuator includes two or more cylinder parts that nest inside each other, each cylinder part including a piston and piston rod forming an operating element and a cylindrical component, inside which the operating element is arranged, the piston of the inner cylinder part being inside the piston rod of the outer cylinder part, chambers formed for each cylinder part, a pressure-medium feed arrangement creating work-movement in the operating element by the pressure medium led to the chambers, a pressure-difference-controlled valve controlling operation of the hydraulic actuator between a first ducting and a second ducting, controlling the feed of the pressure medium among the chambers and a pressure-difference-controlled spool valve including a housing, connecting chambers and a spool arranged to move backwards and forwards in the housing to open and close the connections creating a work movement alternately by the operating element of the inner or outer cylinder part.

A hydraulic actuator includes two or more cylinder parts that nest inside each other, each cylinder part including a piston and piston rod forming an operating element and a cylindrical component, inside which the operating element is arranged, the piston of the inner cylinder part being inside the piston rod of the outer cylinder part, chambers formed for each cylinder part, a pressure-medium feed arrangement creating work-movement in the operating element by the pressure medium led to the chambers, a pressure-difference-controlled valve controlling operation of the hydraulic actuator between a first ducting and a second ducting, controlling the feed of the pressure medium among the chambers and a pressure-difference-controlled spool valve including a housing, connecting chambers and a spool arranged to move backwards and forwards in the housing to open and close the connections creating a work movement alternately by the operating element of the inner or outer cylinder part.

A fluid flow control structure is provided for a telescopic apparatus of a human powered vehicle. The fluid flow control structure basically comprises a first tube, a second tube and a positioning structure. The second tube is telescopically coupled to the first tube to move in an axial direction. The positioning structure includes first, second and third fluid chambers, and a valve that defines a port that is selectively opened and closed. The valve includes a valve body that is movable relative to a valve seat in the axial direction to change a valve state between a closed state and an open state. The valve body fluidly separates the first and second fluid chambers in the closed state and to fluidly connect the first and second fluid chambers in the open state. The third fluid chamber includes a compressible fluid.

A fluid flow control structure is provided for a telescopic apparatus of a human powered vehicle. The fluid flow control structure basically comprises a first tube, a second tube and a positioning structure. The second tube is telescopically coupled to the first tube to move in an axial direction. The positioning structure includes first, second and third fluid chambers, and a valve that defines a port that is selectively opened and closed. The valve includes a valve body that is movable relative to a valve seat in the axial direction to change a valve state between a closed state and an open state. The valve body fluidly separates the first and second fluid chambers in the closed state and to fluidly connect the first and second fluid chambers in the open state. The third fluid chamber includes a compressible fluid.

An aircraft store ejector systems and subsystems thereof. Embodiments can include a two-reservoir re-pressurization system wherein a remote reservoir is used to maintain desired pressure in a local ejector reservoir. The system can include a release valve having a vent valve and valve piston. The release valve can control release of pressurized gas to a pitch control valve. The pitch control valve can be configured to distribute the pressurized gas between two or more ejector piston assemblies. One or more of the ejector piston assemblies can include multiple concentric piston stages and piston chambers, the piston chambers configured to contain a volume of gas. The ejector piston assemblies can be configured to compress the volume of gas within the piston chambers as the piston stages are extended out from the aircraft. Such compression can provide a return force to the piston stages.