A system for controlling trim position of a marine propulsion device on a marine vessel includes a trim actuator having a first end configured to couple to the marine propulsion device and a second end configured to couple to the marine vessel. A controller controls position of the trim actuator between an extended position wherein the propulsion device is trimmed up with respect to the vessel and a retracted position wherein the propulsion device is trimmed down with respect to the vessel. A shock relief mechanism overrides position control by the controller and allows extension of the trim actuator upon the occurrence of an overpressure event. An arresting mechanism, when activated, prevents extension of the trim actuator beyond a certain limit. The controller selectively activates the arresting mechanism in response to a determination that the propulsion device is being commanded in reverse. Methods for controlling trim position are also included.

Disclosed here is a system and method to control multiple eversion-based actuators using a single motor, or no motor, thereby reducing the size and cost of the multiple eversion-based actuators. An activation mechanism can include a motor rotating in an expansion direction, rotating shaft, clutch, brake, pressure source under high pressure, and/or valve. The activation mechanism can cause the actuators including a wound reel of material to unwind and lengthen. A retraction mechanism can include a motor rotating in a contraction direction opposite the expansion direction, rotating shaft, clutch, pressure source having low pressure, valve associated with the pressure source, and/or the passive retraction system. The retraction mechanism can cause the actuators to rewind and shorten.

A support for supporting a structure on a surface, comprising at least one support element, each support element comprising a piston, a cylinder in which the piston is moveable, and a brake for maintaining the piston in a position that is stable relative to the cylinder, wherein the piston and the cylinder are arranged so that a loading associated with the structure effects an adjustment of the support element, and wherein an increase in hydraulic pressure within the cylinder, effected by the loading associated with the structure, activates the brake.

A lock device body includes a brake member fastening a rod to lock the rod, a piston that press-opens a pair of pressure-bearing sections of the brake member by using an expansion member to unlock the rod, and an operation element for manually operating the piston, the operation element includes a shaft threaded in a screw hole, a pressure plate formed on one end of the shaft and located in the pressure chamber, and a sealing member disposed on the pressure plate. When the shaft is threaded into a lock release position, an operation end becomes an unextending state while the pressure plate displaces the piston to the lock release position, and, when the shaft is threaded back to a lock position, the operation end extends from the screw hole to the outside while the sealing member seals the screw hole to isolate the screw hole from the pressure chamber.

A fluid power actuator includes a fluid power actuator housing, a piston assembly, and a screw assembly. The piston assembly is constructed and arranged to move relative to the fluid power actuator housing in response to changes in fluid pressure within the fluid power actuator housing. The screw assembly couples with the fluid power actuator housing and the piston assembly. The screw assembly is constructed and arranged to control movement of the piston assembly relative to the fluid power actuator housing. Such a fluid power actuator is well-suited for various applications such as in loading equipment which is involved in high precision munitions loading, among others.

This disclosure describes techniques for a self-aligning system within a belt-driven linear actuator that enables a keyless or round profile piston to be sealed while maintaining an aligning and/or torque resisting ability. This enables the airspaces within the electromechanical actuator could be pressurized to perform a secondary load holding function that is redundant to the linear screw device.

Methods and systems for a hydraulic axial piston motor with a braking system are described. A brake assembly for a hydraulic axial piston motor, comprising: a cylinder block and a pair of braking pads positioned around the cylinder block, wherein compression of the braking pads against an outer surface of the cylinder block realizes braking of the cylinder block.

The present invention regards a fluid actuator arrangement comprising a first and second cylinder of a cylinder arrangement, a piston rod arrangement, a first and second piston device associated with the piston rod arrangement, wherein respective first and second piston device divides respective first and second cylinder into a first and second chamber provided for connection to a valve device of a fluid supply device. The first piston device comprises a piston rod engagement and disengagement device, which is adapted to engage or disengage the first piston device to/from the piston rod arrangement. The invention can be put into use for aircraft, such as commercial aircraft designed for long distance flights, for construction industry, jacking systems for oil well drilling and service platforms, agricultural equipment industry, marine industry, crane manufacture industry, and others.

Disclosed here is a system and method to control multiple eversion-based actuators using a single motor, or no motor, thereby reducing the size and cost of the multiple eversion-based actuators. An activation mechanism can include a motor rotating in an expansion direction, rotating shaft, clutch, brake, pressure source under high pressure, and/or valve. The activation mechanism can cause the actuators including a wound reel of material to unwind and lengthen. A retraction mechanism can include a motor rotating in a contraction direction opposite the expansion direction, rotating shaft, clutch, pressure source having low pressure, valve associated with the pressure source, and/or the passive retraction system. The retraction mechanism can cause the actuators to rewind and shorten.

An actuator unit includes first and second link mechanisms. The first link mechanism has first and second arms that extend in first and second directions when viewed in a direction parallel to an axis of rotation. The first arm is connected at a first connection point to a power source for powering the first link mechanism. The second arm is connected at a second connection point to the second link mechanism. The second link mechanism is connected at a third connection point to a locking collar. The locking collar is configured to reciprocate as the first link mechanism rotates in a reciprocating manner. The distance from the first connection point to the axis of rotation is greater than the distance from the second connection point to the axis of rotation.