A valve unit for regulating the flow of working fluid between a working chamber of a fluid working machine and both a first working fluid line and second working fluid line, the valve unit comprising: a first valve comprising a first valve member and one or more cooperating first valve seats, a second valve comprising a second valve member and one or more cooperating second valve seats, an actuator coupled to both the first and second valve members through which a force may be applied to urge the first valve member open or closed and to urge the second valve member open or closed, a coupling between the actuator and the first valve member, wherein the coupling between the actuator and the first valve member comprises a connector which extends at least partially through the second valve member.

A valve unit for regulating the flow of working fluid between a working chamber of a fluid working machine and both a first working fluid line and second working fluid line, the valve unit comprising: a first valve comprising a first valve member and one or more cooperating first valve seats, a second valve comprising a second valve member and one or more cooperating second valve seats, an actuator coupled to both the first and second valve members through which a force may be applied to urge the first valve member open or closed and to urge the second valve member open or closed, a coupling between the actuator and the first valve member, wherein the coupling between the actuator and the first valve member comprises a connector which extends at least partially through the second valve member.

A sealing assembly for installation on a port of a spring brake actuator includes a plug, a one-way valve and a cap. The plug receives the one-way valve for providing one-way air flow through the orifices and maintaining about two psi in the spring brake chamber at zero stroke. An elastomeric piece is affixed to a first set of segments of the plug for sealing against an inner surface of the port. The cap has arms sized to extend around a third set of segments of the plug and snap onto the plug. A fourth set of segments of the plug elastically deform so the sealing assembly can be installed and removed from the port easily.

A high efficiency uniflow steam engine with automatic inlet and exhaust valves rather than camshaft operated valves includes an electromagnet and cooperating armature that actuates a cutoff control valve for closing a steam inlet valve at any time selected to stop the flow of steam to the cylinder. Approaching the end of the exhaust stroke typically 0.12 inch before TDC the cylinder is sealed thereby compressing the remaining residual steam down to a minute clearance approaching zero, for example, 0.020 inch to raise cylinder steam pressure enough to open the steam inlet valve without physical contact between the piston and the steam inlet valve thereby eliminating tappet noise, shock and wear.

A high efficiency uniflow steam engine with automatic inlet and exhaust valves rather than camshaft operated valves includes an electromagnet and cooperating armature that actuates a cutoff control valve for closing a steam inlet valve at any time selected to stop the flow of steam to the cylinder. Approaching the end of the exhaust stroke typically 0.12 inch before TDC the cylinder is sealed thereby compressing the remaining residual steam down to a minute clearance approaching zero, for example, 0.020 inch to raise cylinder steam pressure enough to open the steam inlet valve without physical contact between the piston and the steam inlet valve thereby eliminating tappet noise, shock and wear.

It is challenging to detect end of stroke for hydraulically actuated, reciprocating piston pumps for a variety of reasons. When the pump pressurizes a process fluid to a 10 relatively low pressure the magnitude of hydraulic fluid pressure is not as distinct compared to the magnitude of a pressure drop across a shuttle valve employed to detect end of stroke, which makes detecting the end of stroke event difficult. A method is disclosed for detecting end of a piston stroke in a hydraulic motor comprising a reciprocating piston with a shuttle valve. The method comprises 1 detecting end of piston stroke when a magnitude of a rate of change of hydraulic fluid pressure is substantially greater than a magnitude of a mean rate of change of hydraulic fluid pressure over said piston stroke; and noise in a hydraulic fluid pressure signal is substantially negligible.

It is challenging to detect end of stroke for hydraulically actuated, reciprocating piston pumps for a variety of reasons. When the pump pressurizes a process fluid to a 10 relatively low pressure the magnitude of hydraulic fluid pressure is not as distinct compared to the magnitude of a pressure drop across a shuttle valve employed to detect end of stroke, which makes detecting the end of stroke event difficult. A method is disclosed for detecting end of a piston stroke in a hydraulic motor comprising a reciprocating piston with a shuttle valve. The method comprises 1 detecting end of piston stroke when a magnitude of a rate of change of hydraulic fluid pressure is substantially greater than a magnitude of a mean rate of change of hydraulic fluid pressure over said piston stroke; and noise in a hydraulic fluid pressure signal is substantially negligible.

There is provided an R- table apparatus which freely movies one table on a plane in the forward-and-rearward and leftward-and-rightward directions and in the rotational direction. The R- table apparatus changes a horizontal distance between a center line of a main axis of a driving apparatus and the action point by elevating an elevating base, and a table is moved to an arbitrary position without rotating along a guide member.

There is provided an R- table apparatus which freely movies one table on a plane in the forward-and-rearward and leftward-and-rightward directions and in the rotational direction. The R- table apparatus changes a horizontal distance between a center line of a main axis of a driving apparatus and the action point by elevating an elevating base, and a table is moved to an arbitrary position without rotating along a guide member.

A metal member producing device includes a spindle, a base portion, and a driving portion which drives at least one of the spindle and the base portion in an axial direction of the spindle. Of the spindle and the base portion, one includes a first holding portion for holding a first member. The other has disposed thereon a mold for holding a second member to oppose the first holding portion. The mold includes a bottom wall and a sidewall that extends from the bottom wall in a direction intersecting the bottom wall. The sidewall has a resistive wall formed thereon, the resistive wall being a wall surface inclined with respect to a plane parallel to the axial direction of the spindle so as to face the bottom wall side.