Abstract: A multistage piston actuator exerts a driving pressure against a spring pressure into pressure chambers of piston bodies, fitted into a cylinder body, to operate the push rod. Each piston body is combined with a partition fitted into the cylinder body. Each piston body includes a pressure receiving plate portion, and an axial rod and a slidable cylindrical guide portion extending concentrically in opposite directions, the axial rod having an axial air passage connected to the pressure chambers. Each partition includes a base plate portion having a through-hole which receives the axial rod of an adjacent piston body, a large-diameter outermost cylindrical portion fitted into the cylinder body, and a slidable cylindrical guide portion slidably fit-engaged with the slidable cylindrical guide portion of the piston body. The axial rods of each piston body are brought into contact to operate the push rod.

Abstract: A multistage piston actuator exerts a driving pressure against a spring pressure into pressure chambers of piston bodies, fitted into a cylinder body, to operate the push rod. Each piston body is combined with a partition fitted into the cylinder body. Each piston body includes a pressure receiving plate portion, and an axial rod and a slidable cylindrical guide portion extending concentrically in opposite directions, the axial rod having an axial air passage connected to the pressure chambers. Each partition includes a base plate portion having a through-hole which receives the axial rod of an adjacent piston body, a large-diameter outermost cylindrical portion fitted into the cylinder body, and a slidable cylindrical guide portion slidably fit-engaged with the slidable cylindrical guide portion of the piston body. The axial rods of each piston body are brought into contact to operate the push rod.

Abstract: Disclosed is a slow-acting ON/OFF valve which includes a valve-opening pressure chamber that makes an actuating member (which actuates a valve body that comes into contact with and moves away from a valve seat to close and open a flow passage) move in a valve-opening direction against a spring biasing force in a valve-closing direction, and supplies air to the valve-opening pressure chamber, in minute increments, via a flow rate regulation valve. In this slow-acting ON/OFF valve, the dead time from the receipt of a valve-opening signal to the commencement of a valve-opening operation is short. A manifold is provided independently of the valve-opening pressure chamber.

Abstract: A power-assisted mechanism having a simple structure which can perform a power-assisted operation can be achieved in a power-assisted on/off valve including a valve stem which opens and closes a flow passage, an operational member which is positioned on an axis of the valve stem and is relatively movable with respect to the valve stem, and a power-assisted mechanism which reduces the speed and power-assists the movement of the operational member, and transfers the movement of the operational member to the stem valve.

Abstract: Disclosed is a slow-acting ON/OFF valve which includes a valve-opening pressure chamber that makes an actuating member (which actuates a valve body that comes into contact with and moves away from a valve seat to close and open a flow passage) move in a valve-opening direction against a spring biasing force in a valve-closing direction, and supplies air to the valve-opening pressure chamber, in minute increments, via a flow rate regulation valve. In this slow-acting ON/OFF valve, the dead time from the receipt of a valve-opening signal to the commencement of a valve-opening operation is short. A manifold is provided independently of the valve-opening pressure chamber.

Abstract: A power-assisted mechanism having a simple structure which can perform a power-assisted operation can be achieved in a power-assisted on/off valve including a valve stem which opens and closes a flow passage, an operational member which is positioned on an axis of the valve stem and is relatively movable with respect to the valve stem, and a power-assisted mechanism which reduces the speed and power-assists the movement of the operational member, and transfers the movement of the operational member to the stern valve.

Abstract: A normally-closed valve having a microflow rate adjusting device includes a valve stem for opening and closing a fluid passage; a biasing device for biasing the valve stem in a direction to close the fluid passage; a piston body which is engaged in a cylinder in an air-tight manner to form a pressure chamber for moving the valve stem in a valve opening direction against the biasing device; and a stopper mechanism, provided on the cylinder, for controlling a limit of movement of the piston body in the valve opening direction. The stopper mechanism comprises a stroke adjustment member which is screw-engaged with the cylinder coaxially with the valve stem so that a position of the stroke adjustment member relative to the cylinder can be adjusted, and includes an annular tapered surface at an end of the stroke adjustment member which faces the piston body.

Abstract: A rodless cylinder device includes a piston body integrated with the central top portion of a rolling diaphragm, a cylinder body which fixes the circumferential annular fixing portion of the rolling diaphragm and in which the piston body is fitted to be freely movable, a slit which is formed in the cylinder body to extend therethrough and elongated in an axial direction, an inner-to-outer connector fixed to the piston body and projecting outwardly through the slit, an external moving body positioned outside the cylinder body and fixed to the inner-to-outer connector, and a supply and exhaust mechanism, formed between the rolling diaphragm, the cylinder body and the piston body, the supply and exhaust mechanism supplying and exhausting a pressure fluid to and from a pressure chamber.

Abstract: A normally-closed valve having a microflow rate adjusting device includes a valve stem for opening and closing a fluid passage; a biasing device for biasing the valve stem in a direction to close the fluid passage; a piston body which is engaged in a cylinder in an air-tight manner to form a pressure chamber for moving the valve stem in a valve opening direction against the biasing device; and a stopper mechanism, provided on the cylinder, for controlling a limit of movement of the piston body in the valve opening direction. The stopper mechanism comprises a stroke adjustment member which is screw-engaged with the cylinder coaxially with the valve stem so that a position of the stroke adjustment member relative to the cylinder can be adjusted, and includes an annular tapered surface at an end of the stroke adjustment member which faces the piston body.

Abstract: A direct acting pressure reducing valve includes a valve-inlet pressure introduction port; a valve-outlet pressure output port; a main valve for opening and closing a communicating conduit; a pilot pressure chamber formed with a flexible diaphragm member; a communicating hole; a connecting rod inserted in the communicating hole; and a biasing member for biasing the flexible diaphragm member in a direction to open the main valve. An insertion portion of the connecting rod has a partly-deformed circular cross section, a distance from a deformed portion thereof to a center of an imaginary circle corresponding to the communicating hole being shorter than a radius of the imaginary circle. A non-deformed portion of the partly-deformed circular cross section guides the connecting rod along the communicating hole, while the deformed portion serves as an air passage via which the communicating conduit and the pilot pressure chamber are communicatively connected.

Abstract: A direct acting pressure reducing valve includes a valve-inlet pressure introduction port; a valve-outlet pressure output port; a main valve for opening and closing a communicating conduit; a pilot pressure chamber formed with a flexible diaphragm member; a communicating hole; a connecting rod inserted in the communicating hole; and a biasing member for biasing the flexible diaphragm member in a direction to open the main valve. An insertion portion of the connecting rod has a partly-deformed circular cross section, a distance from a deformed portion thereof to a center of an imaginary circle corresponding to the communicating hole being shorter than a radius of the imaginary circle. A non-deformed portion of the partly-deformed circular cross section guides the connecting rod along the communicating hole, while the deformed portion serves as an air passage via which the communicating conduit and the pilot pressure chamber are communicatively connected.

Abstract: A locking device of an air-operated normally-closed valve for a gas cylinder includes a housing; a piston assembly provided in the housing; a tapered axial member having an annular outer tapered surface and positioned coaxially with the piston assembly axis; a lock nut which is screw-engaged with the housing and coaxial with the tapered axial member; an annular inner tapered surface formed on an inner peripheral surface of the lock nut to correspond to the annular outer tapered surface; an intermediate cylinder member positioned between the annular outer and inner tapered surfaces; and a lock piece inserted into a radial through hole and contacting the annular outer and inner tapered surfaces. The lock nut can press the lock piece against the annular outer tapered surface via the annular inner tapered surface to lock the piston assembly by adjusting the lock nut with respect to the housing.

Abstract: An apparatus for manually opening a normally-closed valve includes a value and a hand-operated valve opening jig. The valve includes a working rod for operating a valve element which is moved to close and open a conduit; a cylindrical holder fixed to the working rod, and to which the hand-operated valve opening jig can be detachably attached from the outside of the housing; a biasing member which biases the working rod to close the conduit; and a pressure chamber which is supplied with a working fluid to move the working rod to make the valve element open the conduit. The hand-operated valve opening jig includes a manual-opening attachment which can be detachably attached to the cylindrical holder; and an operational member which is operated to move the working rod in a direction to make the valve element open the conduit via said manual-opening attachment.

Abstract: An apparatus for manually opening a normally-closed valve includes a value and a hand-operated valve opening jig. The valve includes a working rod for operating a valve element which is moved to close and open a conduit; a cylindrical holder fixed to the working rod, and to which the hand-operated valve opening jig can be detachably attached from the outside of the housing; a biasing member which biases the working rod to close the conduit; and a pressure chamber which is supplied with a working fluid to move the working rod to make the valve element open the conduit. The hand-operated valve opening jig includes a manual-opening attachment which can be detachably attached to the cylindrical holder; and an operational member which is operated to move the working rod in a direction to make the valve element open the conduit via said manual-opening attachment.

Abstract: An apparatus for manually opening a normally-closed valve includes a value and a hand-operated valve opening jig. The valve includes a working rod for operating a valve element which is moved to close and open a conduit; a cylindrical holder fixed to the working rod, and to which the hand-operated valve opening jig can be detachably attached from the outside of the housing; a biasing member which biases the working rod to close the conduit; and a pressure chamber which is supplied with a working fluid to move the working rod to make the valve element open the conduit. The hand-operated valve opening jig includes a manual-opening attachment which can be detachably attached to the cylindrical holder; and an operational member which is operated to move the working rod in a direction to make the valve element open the conduit via said manual-opening attachment.

Abstract: A direct acting pressure reducing valve includes a valve-inlet pressure introduction port; a valve-outlet pressure output port; a main valve for opening and closing a communicating conduit; a pilot pressure chamber formed with a flexible diaphragm member; a communicating hole; a connecting rod inserted in the communicating hole; and a biasing member for biasing the flexible diaphragm member in a direction to open the main valve. An insertion portion of the connecting rod has a partly-deformed circular cross section, a distance from a deformed portion thereof to a center of an imaginary circle corresponding to the communicating hole being shorter than a radius of the imaginary circle. A non-deformed portion of the partly-deformed circular cross section guides the connecting rod along the communicating hole, while the deformed portion serves as an air passage via which the communicating conduit and the pilot pressure chamber are communicatively connected.

Abstract: A locking device of an air-operated normally-closed valve for a gas cylinder includes a housing; a piston assembly provided in the housing; a tapered axial member having an annular outer tapered surface and positioned coaxially with the piston assembly axis; a lock nut which is screw-engaged with the housing and coaxial with the tapered axial member; an annular inner tapered surface formed on an inner peripheral surface of the lock nut to correspond to the annular outer tapered surface; an intermediate cylinder member positioned between the annular outer and inner tapered surfaces; and a lock piece inserted into a radial through hole and contacting the annular outer and inner tapered surfaces. The lock nut can press the lock piece against the annular outer tapered surface via the annular inner tapered surface to lock the piston assembly by adjusting the lock nut with respect to the housing.

Abstract: A multi-stage piston actuator includes an operation stem, a plurality of pistons provided on the operation stem at different axial positions, a cylinder in which the pistons are slidably fitted, and a separation wall provided within the cylinder, which defines pressure chambers corresponding to the pistons. The separation wall is made of a cup-shaped member which is provided with a central cylindrical portion in which the operation stem slides, a peripheral cylindrical portion which is fitted in and secured to an inner wall surface of the cylinder, and a circular disc portion which connects the central cylindrical portion and the peripheral cylindrical portion.

Abstract: An apparatus for manually opening a normally-closed valve includes a value and a hand-operated valve opening jig. The valve includes a working rod for operating a valve element which is moved to close and open a conduit; a cylindrical holder fixed to the working rod, and to which the hand-operated valve opening jig can be detachably attached from the outside of the housing; a biasing member which biases the working rod to close the conduit; and a pressure chamber which is supplied with a working fluid to move the working rod to make the valve element open the conduit. The hand-operated valve opening jig includes a manual-opening attachment which can be detachably attached to the cylindrical holder; and an operational member which is operated to move the working rod in a direction to make the valve element open the conduit via said manual-opening attachment.

Abstract: A multistage switching valve includes a valve stem which is adapted to open or close a fluid passage, a biasing biasing means for biasing the valve stem in a direction to close the fluid passage, a plurality of pistons which are relatively slidably fitted onto the valve stem at different axial positions to provide different flow rates, a plurality of stops which are provided on the valve stem to move the valve stem in a valve opening direction opposite to the direction of the movement of the valve stem caused by the biasing biasing means, together with the pistons when the pistons are moved in the valve opening direction, a valve opening means for exerting a pilot pressure in the valve opening direction on each piston, and a flow rate controller for individually restricting the axial displacements of the pistons in the valve opening direction. A two-stage switching valve and a toggle type two-stage switching valve are also disclosed.