To be able to set a spring force of a first simulator spring of a pedal travel simulator of a hydraulic power vehicle braking system, a stroke limiter is provided, which is situated between a simulator piston and the simulator spring, including two rams projecting in opposite directions as stops, which are plastically compressed for setting the spring force. To set a jump-in, the stroke limiter includes laterally projecting, plastically bendable wings as supports for a second simulator spring, which is situated between the stroke limiter and the simulator piston.

Hydraulically-amplified, self-healing, electrostatic transducers that harness electrostatic and hydraulic forces to achieve various actuation modes. Electrostatic forces between electrode pairs of the transducers generated upon application of a voltage to the electrode pairs draws the electrodes in each pair towards each other to displace a liquid dielectric contained within an enclosed internal cavity of the transducers to drive actuation in various manners. The electrodes and the liquid dielectric form a self-healing capacitor whereby the liquid dielectric automatically fills breaches in the liquid dielectric resulting from dielectric breakdown. Due to the resting shape of the cavity, a zipping-mechanism allows for selectively actuating the electrodes to a desired extent by controlling the voltage supplied.

Hydraulic or pseudo hydraulic methods and apparatus using component area ratios to amplify the displacement or force responses of super-elastic (SE) and shape memory actuator (SMA) devices by means mechanically coupled to the SE/SMA devices.

Hydraulic or pseudo hydraulic methods and apparatus using component area ratios to amplify the displacement or force responses of super-elastic (SE) and shape memory actuator (SMA) devices by means mechanically coupled to the SE/SMA devices.

A nozzle of or for a servo valve comprises a nozzle element having a fluid outlet at a first axial end and a tubular body extending from the first end to an opposed, second axial end. The nozzle further comprises a plug element mounted in and closing the second axial end of the tubular body, thereby defining an internal cavity within the tubular body. One or more openings are formed through the tubular body to fluidly communicate with the internal cavity. A filter may be mounted across the internal cavity at a position axially intermediate the openings and the fluid outlet.

A pneumatic valve arrangement for a pneumatically operated field device, such as a control device, of a processing plant, such as a chemical plant, a foodstuff processing plant, a power plant or the like is disclosed. The valve arrangement may include an air supply conduit for receiving pressurized air from a source of pressurized air, a control air conduit for aerating and venting a pneumatic actor of the field device, and a venting conduit for discharging pressurized air to a pressure sink, such as the atmosphere; a venting valve for opening and/or closing the venting conduit and an aerating valve for opening and/or closing the air supply conduit; and a pivotable carrier lever for common actuation of the aerating valve and of the venting valve, wherein the carrier lever holds the venting valve in its closed position while it opens the aerating valve from its closed position.

An example apparatus includes: a plate configured to move along an underlying surface via a layer of fluid disposed in a gap between the plate and the underlying surface, where pressurized fluid forms the layer of fluid in the gap; a first rack gear coupled to the plate and meshing with a first gear; and a second rack gear coupled to a second gear. The second rack gear is fixed, and the second gear is coupled to the first gear. The pressurized fluid in the gap repels the plate away from the underlying surface, thereby causing (i) the first rack gear to move linearly and the first gear to rotate, (ii) the second gear to rotate and move along the second rack gear, and (iii) the plate to move along the underlying surface.

An example apparatus includes: a plate configured to move along an underlying surface via a layer of fluid disposed in a gap between the plate and the underlying surface, where pressurized fluid forms the layer of fluid in the gap; a first rack gear coupled to the plate and meshing with a first gear; and a second rack gear coupled to a second gear. The second rack gear is fixed, and the second gear is coupled to the first gear. The pressurized fluid in the gap repels the plate away from the underlying surface, thereby causing (i) the first rack gear to move linearly and the first gear to rotate, (ii) the second gear to rotate and move along the second rack gear, and (iii) the plate to move along the underlying surface.

A propeller hydraulic actuation system, includes a double-acting dual chamber hydraulic pitch change actuator. The pitch change actuator includes a first pressure circuit having first fluid supply lines and a first hydraulic chamber and a second pressure circuit having second fluid supply lines and a second hydraulic chamber. A piston separates the first and second chambers. At least one pressure sensor is provided for obtaining pressure measurements from which a load differential (F) applied to the piston by the circuits can be calculated. A closed loop controller is arranged to control the fluid supplied to the first and second pressure circuits, wherein the closed loop controller includes an actuator position loop arranged to utilise feedback on the actuator position to control the actuator position.

In a closed loop control method for an electropneumatic field device, an electronic target value input of a command variable corresponding to a target value of a control center is received by the open loop and/or closed loop control electronics, an electronic output for a manipulating variable to pilot the electropneumatic converter is generated by the open loop and/or closed loop control electronics; and, in a predetermined operating condition of the field device, the manipulating variable is determined by a closed loop control algorithm based on the command variable and on another controlled variable different from an actual control member position measurement value.