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.

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.

A piston-cylinder assembly (1) has a cylindrical housing (3), with a main piston (2) and at least one trailing piston (11, 12). The trailing piston (11, 12) is axially guided on a cylindrical outer lateral face (38) of the main piston (2). The trailing piston (11, 12) has a thrust portion (13, 14) at one end near a piston web on the main piston, The thrust portion extends axially inward toward the piston web (10) A travel limiter (28) on the cylindrical housing limits a travel range of the trailing piston (11, 12) Under pressure, the trailing piston (11, 12) follows the main piston (2) until the trailing piston (11, 12) hits the travel limiter (28). The thrust portion (13, 14) of the trailing piston (11, 12) is shaped to fit into an associated recess (30, 31) in the piston web with a positive lock.

An actuator assembly comprises a housing having a piston at least partially disposed therein. The actuator assembly includes at least one biasing mechanism disposed within the housing to selectively position the piston between a first position, a second position, and a third position located between the first and second positions.

The invention relates to hydraulic cylinder devices and can be used in vehicle transmissions. A three-position pneumatic or hydraulic cylinder consists of a housing having end caps, two pistons, a rod, and supply channels for a working fluid, each piston being configured for limited movement along the rod as a result of a central protuberance, which separates the pistons, and peripheral protuberances on the rod, and being configured for limited movement inside the housing. The central protuberance is configured in the form of a bushing, and an annular protuberance is, configured on the inside surface of the housing. Said bushing and said protuberance form a hermetic moveable coupling of the shaft/opening type. Separate channels are provided for supplying working fluid to the chambers formed by each piston and the corresponding end of the housing, and a shared channel is provided for supplying working fluid to the chambers formed by each piston and the central protuberance and bushing; or, separate channels are provided for supplying working fluid to the chambers formed by each piston and the central protuberance and bushing, and a shared channel is provided for supplying working fluid to the chambers formed by each piston and the corresponding end of the housing.

The invention relates to hydraulic cylinder devices and can be used in vehicle transmissions. A three-position pneumatic or hydraulic cylinder consists of a housing having end caps, two pistons, a rod, and supply channels for a working fluid, each piston being configured for limited movement along the rod as a result of a central protuberance, which separates the pistons, and peripheral protuberances on the rod, and being configured for limited movement inside the housing. The central protuberance is configured in the form of a bushing, and an annular protuberance is, configured on the inside surface of the housing. Said bushing and said protuberance form a hermetic moveable coupling of the shaft/opening type. Separate channels are provided for supplying working fluid to the chambers formed by each piston and the corresponding end of the housing, and a shared channel is provided for supplying working fluid to the chambers formed by each piston and the central protuberance and bushing; or, separate channels are provided for supplying working fluid to the chambers formed by each piston and the central protuberance and bushing, and a shared channel is provided for supplying working fluid to the chambers formed by each piston and the corresponding end of the housing.

A flow path switching device includes: a first passage portion; a second passage portion; a first cover member attached to the first passage portion; and a second cover member attached to the second passage portion. The first passage portion includes a first passage connected to a fluid circuit and having a groove shape. The second passage portion includes a second passage connected to the fluid circuit to communicate with the first passage at a plurality of places and having a groove shape. The first passage portion, the second passage portion, and a drive unit are stacked in this order. The first cover member includes: a sealing portion to seal an opened portion of the first passage; and an opening arranged along an outer edge of the opened portion of the first passage.

Fail-fixed hydraulic actuator systems for aircraft include a hydraulic actuator having a piston in a housing. The piston separates the housing into a retract cavity and an extend cavity. A sleeve is moveably arranged within the housing and includes a sleeve aperture that is aligned with a piston head during normal operation. A driving mechanism is configured to drive movement of the sleeve to maintain alignment between the sleeve aperture and the piston head. A low pressure cavity is defined between an interior surface of the housing and the sleeve and, when the piston head is offset from the sleeve aperture, the low pressure cavity is hydraulically connected to one of the retract cavity or the extend cavity to cause a pressure differential with the other of the extend cavity and the retract cavity and cause movement of the piston head to align with the sleeve aperture.

Fail-fixed hydraulic actuator systems for aircraft include a hydraulic actuator having a piston in a housing. The piston separates the housing into a retract cavity and an extend cavity. A sleeve is moveably arranged within the housing and includes a sleeve aperture that is aligned with a piston head during normal operation. A driving mechanism is configured to drive movement of the sleeve to maintain alignment between the sleeve aperture and the piston head. A low pressure cavity is defined between an interior surface of the housing and the sleeve and, when the piston head is offset from the sleeve aperture, the low pressure cavity is hydraulically connected to one of the retract cavity or the extend cavity to cause a pressure differential with the other of the extend cavity and the retract cavity and cause movement of the piston head to align with the sleeve aperture.

A system (100), including: a fluidic actuator (2) which can be acted upon by a pressurized fluid and has an actuator member (3), a pressurized fluid provision device (4) which is adapted to carry out a position control of the actuator member (3) and, within the position control, to apply the pressurized fluid to the fluidic actuator (2) in order to move the actuator (3) into a prescribed position, the pressurized fluid provision device (4) being adapted to carry out the position control taking into account at least one system parameter, which describes a physical property of the system and/or a requirement parameter which defines a requirement for the positioning of the actuator (3), wherein the pressurized fluid provision device (4) is further adapted to perform an assistance procedure and to determine and/or verify, within the assistance procedure, the system parameter and/or the requirement parameter on the basis of a movement of the actuator (3) and/or a consideration of physical limits.