Abstract: In a putter shaft having a tip end and a butt end, a curvature of the putter shaft is represented by a curvature curve of the putter shaft which increases monotonously from the tip end to the butt end. The curvature curve is defined as a curve showing variation of the curvature in a longitudinal axis direction of the putter shaft in a state where a load acts on the tip end to deform the putter shaft with the putter shaft being fixed at the butt end.

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 electro-pneumatic air pressure regulator includes a primary pressure introduction port, a secondary pressure output port, a pilot pressure chamber, a main valve for opening and closing a communicating conduit, a floating piston which actuates the main valve, a nozzle conduit via which the pilot pressure chamber is communicatively connected to the atmosphere, a flapper which includes a leaf spring facing an open end of the nozzle conduit, and an electromagnetic drive system which deforms the leaf spring to vary a position of the flapper relative to the open end of the nozzle conduit in accordance with the magnitude of an analogue input signal. The flapper includes a conical projection which projects toward the open end of the nozzle conduit. A conical recess corresponding to the conical projection is formed on an end face of the nozzle conduit around the open end thereof.

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 method for forming a hollow FRP article by internal pressure molding includes positioning a FRP prepreg on a periphery of an airtight internal-pressure holding tube, inserting a composite body including the internal-pressure holding tube and the prepreg into a vacuum chamber containing a forming die, evacuating the vacuum chamber in an isolation state where the composite body and the forming die do not contact each other, and clamping the forming die to bring the forming die and the composite body into contact with each other and heating the forming die with an application of pressure to an inside of the internal-pressure holding tube after completion of the evacuating step.

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 vibration isolation table includes a stationary housing having an opening on top thereof; a pressure-tight flexible member which closes the opening to form a first pressure chamber in the stationary housing; a primary movable base which is coupled to a central portion of the pressure-tight flexible member, the primary movable base having a bottomed hollow cylindrical member; an intermediate movable base having a swingable rod which is inserted into the bottomed hollow cylindrical member so that a bottom end of the swingable rod is supported thereby to allow the swingable rod to swing with respect to the bottomed hollow cylindrical member; and a vibration-free base on which an object to be isolated from vibration is mounted, a second pressure chamber being formed between the intermediate movable base and the vibration-free base, the second pressure chamber being capable of expanding and contracting vertically.

Abstract: A vibration isolation table includes a stationary housing having an opening on a top surface thereof; a primary movable base which is supported by the stationary housing, and includes a bottomed hollow cylindrical portion which extends downwards into the stationary housing, and a flange portion which projects radially outwards from an upper end of the bottomed hollow cylindrical portion; a pressure chamber formed between the flange portion and the top surface of the stationary housing; and a vibration-free movable base on which an object to be isolated from vibration is mounted, the vibration-free movable base having a swingable rod which is inserted into the bottomed hollow cylindrical portion so that a bottom end of the swingable rod is supported by a base of the bottomed hollow cylindrical portion in a manner to allow the swingable rod to swing with respect to the bottomed hollow cylindrical portion.

Abstract: A racket includes a frame portion and a string which is threaded through the frame portion to be interlaced so as to form a first set of parallel string paths, a second set of parallel string paths, and a third set of parallel string paths. The string is threaded through the frame portion via the first, second and third sets of parallel string paths so that the string forms an approximately planar racket face. The first, second and third sets of parallel string paths intersect each other by an angle of approximately 120 degrees.

Abstract: In a putter shaft having a tip end and a butt end, a curvature of the putter shaft is represented by a curvature curve of the putter shaft which increases monotonously from the tip end to the butt end. The curvature curve is defined as a curve showing variation of the curvature in a longitudinal axis direction of the putter shaft in a state where a load acts on the tip end to deform the putter shaft with the putter shaft being fixed at the butt end.

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: A golf club shaft made of a composite of a fiber material and a synthetic resin material, wherein the fiber material includes triaxial fabric layers which are located at least on the butt end side and the tip end side of the golf club shaft. Either the fiber density, the kind of the fiber, the physical property of the fiber, or a combination of two or more thereof, of yarn paths of three directions that form the triaxial fabric layers is varied with respect to the longitudinal axis of the shaft in accordance with a required specification of the shaft.

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.

Abstract: An automatic two-stage switching valve includes a valve stem which normally closes a fluid passage by a spring force; a cylinder adopted to accommodate the valve stem; a large flow rate piston and a small flow rate piston that are provided on the valve stem and are slidably fitted in the cylinder; a large flow rate pilot pressure chamber formed in the cylinder; a small flow rate pilot pressure chamber formed in the cylinder; a stopper adopted to restrict the movement of the small flow rate piston; a pilot pressure source adopted to apply the pilot pressure simultaneously to both the large and small flow rate pilot pressure chambers; and a restrictor provided in a connection passage that connects the pilot pressure source to the large flow rate pilot pressure chamber.

Abstract: With respect to the cross-sectional profile of the shaft, the grip and the socket of a golf club in the direction perpendicular to the center axis line thereof, the inside portion which is located inwardly from the center axis line is formed of a material having a larger specific gravity than the outside portion (at the head side) which is located outwardly from the center axis line to provide a weight difference between the outside and inside portions of each of the shaft, the grip and the socket with making no variation to the shape of the cross-sectional profile. The weight difference is set to such a value that when the shaft, the grip or the socket is rolled on the horizontal plane, each is stopped with the same portion placed face down. More specifically, the weight difference between the outside (upper) portion and the inside (lower) portion with respect to the center axis line is set to 2 g or more for the shaft, 3 g or more for the grip and 0.1 g or more for the socket.

Abstract: A toggle valve includes a valve stem which moves a valve body towards and away from a valve seat, an operation member separate from the valve stem, valve stem rollers which are supported by the valve stem and which have shafts whose axes extend in a direction perpendicular to the direction of the sliding movement of the valve stem without intersecting the same, a tapered surface provided on the end of the operation member adjacent to the valve stem, and intermediate rollers which are provided between the tapered surface of the operation member and the valve stem rollers to come into contact with the tapered surface and the valve stem rollers.

Abstract: A method for measuring the torsional rigidity distribution of a shaft comprises the steps of; disposing a shaft to be measured in a vertical position in which the upper end thereof is immovably held and the lower end of the shaft is rotatable about the axis of the shaft, demarcating the shaft along its length so as to establish a number of discrete sections of the shaft, performing measurements of the torsional frequency of an inertial mass held at designated discrete positions shaft, and calculating the torsional rigidity of each discrete section based on the measured torsional frequencies.

Abstract: A method for measuring a mass distribution of a shaft in a longitudinal axis direction thereof includes the steps of firstly, setting a plurality of measuring areas on a shaft to be measured. The measuring areas are split in the longitudinal axis direction of the shaft. Secondly, a constant amount of .beta. rays are emitted onto each measuring area from one side of the shaft in the radial direction. The amount of .beta. rays transmitted through the measuring areas of the shaft is measured at the other side of the shaft. Thirdly, the diameter of the shaft at each measuring area is measured to obtain a relative mass distribution of the shaft in the longitudinal axis direction in accordance with the.beta. ray data representing the amount of .beta. rays transmitted through each measuring area and the diameter data. A method for measuring a mass distribution of a shaft in the circumferential direction thereof is also disclosed.

Abstract: A golf club shaft is composed of a fiber layer formed by employing a filament winding process using filaments each impregnated with a thermosetting resin, and a reinforcement layer formed by partially inserting a braid impregnated with a thermosetting resin onto a predetermined position on the fiber layer. A method of producing a golf club shaft of the foregoing type comprises a step of winding filaments each impregnated with a thermosetting resin around a mandrel to form a fiber layer, a step of inserting a braid composed of filaments each impregnated with a thermosetting resin onto a predetermined position on the fiber layer, a step of allowing the thermosetting resin to be thermally cured, and a step of disconnecting the mandrel.