Systems and methods include providing an aircraft with a direct drive dual-concentric valve (D3V) having a body, an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body, an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body. A plurality of piezo stacks is coupled to a first end of the primary spool, and applying a voltage to at least one of the piezo stacks causes an output stroke of the plurality of the piezo strokes for displacing the primary spool. The secondary spool is displaced together with the primary spool relative to the body if displacement of the primary spool relative to the secondary spool cannot occur.

Systems and methods include providing an aircraft with a direct drive dual-concentric valve (D3V) having a body, an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body, an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body. A plurality of piezo stacks is coupled to a first end of the primary spool, and applying a voltage to at least one of the piezo stacks causes an output stroke of the plurality of the piezo strokes for displacing the primary spool. The secondary spool is displaced together with the primary spool relative to the body if displacement of the primary spool relative to the secondary spool cannot occur.

A generator is described comprising in particular a vertical supply column that can be filled with a certain quantity of liquid, an intake valve disposed at a base of the vertical supply column, and a leaktight tank communicating with the vertical supply column via the intake valve, which leaktight tank can be filled with liquid. The generator also comprises an exhaust valve disposed on the leaktight tank and capable of releasing pressure generated in the leaktight tank, and a piston-forming device disposed inside the leaktight tank so as to be immersed in the liquid contained in the leaktight tank. This piston-forming device is capable of being set in reciprocating movement between an upper position and a lower position, the piston-forming device comprising a first, float-forming portion capable of bringing the piston-forming device into the upper position and a second portion forming an output shaft. The generator further comprises a converter device coupled to the output shaft, which converter device is capable of converting the reciprocating movement of the piston-forming device into mechanical or electrical energy. The generator is configured in such a way that, in operation, the leaktight tank is filled with liquid, and in such a way as to repeat a sequence of operating phases in order to induce the reciprocating movement of the piston-forming device.

A generator is described comprising in particular a vertical supply column that can be filled with a certain quantity of liquid, an intake valve disposed at a base of the vertical supply column, and a leaktight tank communicating with the vertical supply column via the intake valve, which leaktight tank can be filled with liquid. The generator also comprises an exhaust valve disposed on the leaktight tank and capable of releasing pressure generated in the leaktight tank, and a piston-forming device disposed inside the leaktight tank so as to be immersed in the liquid contained in the leaktight tank. This piston-forming device is capable of being set in reciprocating movement between an upper position and a lower position, the piston-forming device comprising a first, float-forming portion capable of bringing the piston-forming device into the upper position and a second portion forming an output shaft. The generator further comprises a converter device coupled to the output shaft, which converter device is capable of converting the reciprocating movement of the piston-forming device into mechanical or electrical energy. The generator is configured in such a way that, in operation, the leaktight tank is filled with liquid, and in such a way as to repeat a sequence of operating phases in order to induce the reciprocating movement of the piston-forming device.

Disclosed is an active chamber engine including a cylinder fed with compressed air, a piston, a cylinder head which includes an intake duct, an intake orifice, an intake valve, wherein the volume of the cylinder is divided into an included active chamber and an expansion chamber and the torque and the speed of the engine are controlled by the opening and closing of the intake valve characterized in that the intake valve moves in the direction opposite to the flow direction of the pressurized gas stream in its opening direction and is held closed on a seat by a return spring in its closing position, and that the axial forces acting on the intake valve resulting from the pressure in the intake duct and in the cylinder are permanently balanced.

Disclosed is an active chamber engine including a cylinder fed with compressed air, a piston, a cylinder head which includes an intake duct, an intake orifice, an intake valve, wherein the volume of the cylinder is divided into an included active chamber and an expansion chamber and the torque and the speed of the engine are controlled by the opening and closing of the intake valve characterized in that the intake valve moves in the direction opposite to the flow direction of the pressurized gas stream in its opening direction and is held closed on a seat by a return spring in its closing position, and that the axial forces acting on the intake valve resulting from the pressure in the intake duct and in the cylinder are permanently balanced.

A pressure-limiting unit for a pressure booster for driving hydraulic tools. The unit includes a pneumatic unit that is driven by gas or air pressure, a hydraulic unit connected to the pneumatic unit and having a hydraulic port for connecting the hydraulic tool to the hydraulic unit in a fluid-tight manner and a pressure-limiting valve for adjusting the hydraulic pressure. The unit includes a closing element pushed against a valve seat by a spring element and having a displaceable adjusting element for adjusting the spring force of the spring element. To provide a pressure-limiting unit and a pressure booster for driving hydraulic tools with a pressure-limiting unit, which offer the possibility of making a precise adjustment of the hydraulic pressure in a simple way, the pressure-limiting unit includes a position detection unit connected to the adjusting element to detect the axial position of the adjusting element, an evaluation unit for determining the set hydraulic pressure as a function of the axial position, and an output unit for displaying the set hydraulic pressure.

A pressure-limiting unit for a pressure booster for driving hydraulic tools. The unit includes a pneumatic unit that is driven by gas or air pressure, a hydraulic unit connected to the pneumatic unit and having a hydraulic port for connecting the hydraulic tool to the hydraulic unit in a fluid-tight manner and a pressure-limiting valve for adjusting the hydraulic pressure. The unit includes a closing element pushed against a valve seat by a spring element and having a displaceable adjusting element for adjusting the spring force of the spring element. To provide a pressure-limiting unit and a pressure booster for driving hydraulic tools with a pressure-limiting unit, which offer the possibility of making a precise adjustment of the hydraulic pressure in a simple way, the pressure-limiting unit includes a position detection unit connected to the adjusting element to detect the axial position of the adjusting element, an evaluation unit for determining the set hydraulic pressure as a function of the axial position, and an output unit for displaying the set hydraulic pressure.

A high efficiency uniflow steam engine having automatic poppet valves yieldably based by fluid such as steam held under pressure within a cavity in the engine and a cutoff control for closing a steam inlet valve at any time selected stops the flow of steam into the cylinder. Proximate the end of the exhaust stroke, around 0.12 inch before TDC the cylinder is sealed to thereby compress residual steam as the piston clearance approaches zero; typically, 0.020 inch which raises cylinder pressure enough to open an inlet valve without making physical contact to push the inlet valve open with the piston thereby eliminating a tappet type of noise, shock and wear.

A high efficiency uniflow steam engine having automatic poppet valves yieldably based by fluid such as steam held under pressure within a cavity in the engine and a cutoff control for closing a steam inlet valve at any time selected stops the flow of steam into the cylinder. Proximate the end of the exhaust stroke, around 0.12 inch before TDC the cylinder is sealed to thereby compress residual steam as the piston clearance approaches zero; typically, 0.020 inch which raises cylinder pressure enough to open an inlet valve without making physical contact to push the inlet valve open with the piston thereby eliminating a tappet type of noise, shock and wear.