Abstract: A valve core for opening and closing a core mounting throughbore includes a cylindrical core body fixed inside the throughbore and having a distal opening, a moving shaft inserted through the core body so as to be directly moved and having an end, a plug formed integrally at the end side of the moving shaft so as to open and close the distal opening of the core body, a biasing member biasing the moving shaft so that the distal opening of the core body is closed by the plug, a cylindrical sealing member, an outer sealing portion formed integrally on the cylindrical sealing member and fitted with the outer periphery of the core body so as to be held between the core body and the inner wall of the throughbore thereby to adhere closely to the outer periphery of the core body, and an inner sealing portion formed integrally on the cylindrical sealing member so as to adhere closely to an outer face of the plug.

Abstract: A transmitter has a valve stem, an electronic element, a casing and a coupler. The valve stem permits flow of air into the tire. The electronic element transmits a data representing the condition of the tire. The casing accommodates the electronic element. The coupler couples the valve stem to the casing such that an angle of the casing relative to the valve stem is adjustable be controlled. This can be attached to wheels having different cross-sectional shape.

Abstract: A valve is generally elongated in shape and is inserted through an O-ring and amounting hole formed through a plate-shaped member. The valve includes a thread formed on an outer circumferential face of the valve so that a generally annular fitting is engaged therewith, an outer protruding wall protruding from the outer circumferential face of the valve to hold a circumferential edge of the mounting hole in cooperation with the fitting, a tapered portion formed in the outer protruding wall so as to be tapered toward the fitting and so as to abut against a part of the circumferential edge of the mounting hole, and a sealing portion disposed at a side farther away from the plate-shaped member than a portion of the protruding wall abutting against said circumferential edge part of the mounting hole so that each of the plate-shaped member and the sealing portion presses the O-ring against the other.

Abstract: A valve core for opening and closing a core mounting throughbore includes a cylindrical core body fixed inside the throughbore and made of a metal having a hardness differing from an inner wall of the throughbore, the core body having a distal opening, a moving shaft inserted through the core body so as to be directly moved and made of a metal having a hardness differing from the core body, the moving shaft having an end, a plug formed integrally at the end side of the moving shaft so as to open and close the distal opening of the core body, a biasing member biasing the moving shaft so that the distal opening of the core body is closed by the plug, a body positioning abutment formed on an outer face of the core body so as to abut the inner wall of the throughbore, thereby providing a metal seal for a gap between the inner wall of the throughbore and the outer face of the core body, and an abutting taper formed on the plug so as to abut an inner edge of the distal opening of the core body, thereby providing a

Abstract: A valve core for opening and closing a core mounting throughbore includes a cylindrical core body fixed inside the throughbore and having a distal opening, a moving shaft inserted through the core body so as to be directly moved and having an end, a plug formed integrally at the end side of the moving shaft so as to open and close the distal opening of the core body, a biasing member biasing the moving shaft so that the distal opening of the core body is closed by the plug, a cylindrical sealing member, an outer sealing portion formed integrally on the cylindrical sealing member and fitted with the outer periphery of the core body so as to be held between the core body and the inner wall of the throughbore thereby to adhere closely to the outer periphery of the core body, and an inner sealing portion formed integrally on the cylindrical sealing member so as to adhere closely to an outer face of the plug.

Abstract: A relief valve includes an outer stem including a larger diameter fitting section and a smaller diameter fitting section, a movable valve element fitted in both fitting sections so as to be moved between an opening position and a closing position, a communication space extending through the stem and the valve element so that a compressed fluid flows through the space, a first normally closed seal disposed between the valve element and the smaller fitting section for closing a part of a circumferential gap defined between the valve element and the stem, a second seal disposed between the valve element and the larger diameter fitting section for closing a part of the circumferential gap extending from the larger diameter fitting section side to the communication space when the movable valve element has been moved to the closing position, the second seal opening the part when the movable valve element has been moved to the opening position, a relief hole formed in the stem so that the circumferential gap normall

Abstract: A relief valve includes an outer stem including a larger diameter fitting section and a smaller diameter fitting section, a movable valve element fitted in both fitting sections so as to be moved between an opening position and a closing position, a communication space extending through the stem and the valve element so that a compressed fluid flows through the space, a first normally closed seal disposed between the valve element and the smaller fitting section for closing a part of a circumferential gap defined between the valve element and the stem, a second seal disposed between the valve element and the larger diameter fitting section for closing a part of the circumferential gap extending from the larger diameter fitting section side to the communication space when the movable valve element has been moved to the closing position, the second seal opening the part when the movable valve element has been moved to the opening position, a relief hole formed in the stem so that the circumferential gap normall

Abstract: A tire pressure holding system for a vehicle includes a pump mounted in the center of a wheel for discharging compressed air in synchronization with revolution of the wheel, the pump including a discharge section from which the compressed air is discharged, a conduit connected to the interior of the tire and the discharge section of the pump, a check valve mounted in the conduit for preventing the air in the interior of the tire from flowing to the pump side, and a release valve mounted in the conduit for releasing the compressed air from the pump outside when an internal pressure is at or above a predetermined value in a section of the interior of the conduit between the check valve and the pump.

Abstract: A transmitter has a valve stem, an electronic element, a casing and a coupler. The valve stem permits flow of air into the tire. The electronic element transmits a data representing the condition of the tire. The casing accommodates the electronic element. The coupler couples the valve stem to the casing such that an angle of the casing relative to the valve stem is adjustable be controlled. This can be attached to wheels having different cross-sectional shape.

Abstract: A valve is generally elongated in shape and is inserted through an O-ring and amounting hole formed through a plate-shaped member. The valve includes a thread formed on an outer circumferential face of the valve so that a generally annular fitting is engaged therewith, an outer protruding wall protruding from the outer circumferential face of the valve to hold a circumferential edge of the mounting hole in cooperation with the fitting, a tapered portion formed in the outer protruding wall so as to be tapered toward the fitting and so as to abut against a part of the circumferential edge of the mounting hole, and a sealing portion disposed at a side farther away from the plate-shaped member than a portion of the protruding wall abutting against said circumferential edge part of the mounting hole so that each of the plate-shaped member and the sealing portion presses the O-ring against the other.