Fujikura Rubber Ltd.

Daikin Industries, Ltd.

Hitachi Metals, Ltd.

Norio Matsumoto

Masaki Wakabayashi

Teruo Umehara

Takato Nakamura

Shigeharu Shikano

Hideaki Sanekata

Harunori Miyamura

Nozomi Gotou

Hideyuki Gotou

Naoki Kimoto

Akiyasu Higuchi

Koichi Kameoka

Hiromichi Ueno

Tetsuto Minowa

Tomonobu Kanno

A screw compressor includes a casing and a compression mechanism accommodated in the casing. The compression mechanism has a screw rotor, a gate rotor and a communication mechanism. The gate rotor has a flat plate shape. A rotational axis of gate rotor is orthogonal to a rotational axis of the screw rotor. The communication mechanism is arranged to communicate a high pressure space and a low pressure space in the casing.

Screw compressor having reverse rotation protection

A method is provided for producing a weight-reduced FRP cylinder which can attain high strength, and also such an FRP cylinder is provided. This FRP cylinder producing method, in which a plurality of prepregs formed by impregnating reinforced fibers with thermosetting resin sheets are wound into a cylinder and thermally cured to be formed as a plurality of FRP layers, includes a simultaneous multilayer winding process in which a torsional rigidity retaining prepreg and a buckling prevention prepreg are continuously wound a plurality of turns with being layered on each other when the plurality of prepregs are wound into a cylinder, wherein the torsional rigidity retaining prepreg includes a layer of fibers oblique to a cylindrical axis direction of the FRP cylinder, and wherein the buckling prevention prepreg includes a layer of fibers orthogonal to the cylindrical axis direction.

Method for producing FRP cylinder and FRP cylinder

A prepreg winding method includes the steps of preparing a plate, a mandrel movable toward and away from the plate, and a press roll movable toward and away from the mandrel and having an axis parallel to the mandrel; mounting a prepreg on the plate, the prepreg being formed by impregnating reinforced fibers with a thermosetting resin sheet; winding a leading end of the prepreg mounted on the plate around the mandrel, and making a pressing force act on the plate and the mandrel therebetween with the prepreg sandwiched between the plate and the mandrel and making a pressing force act on the mandrel and the press roll therebetween with the prepreg sandwiched between the mandrel and the press roll; and winding the prepreg around the mandrel by rotating the mandrel and the press roll.

Prepreg winding method and apparatus

A screw compressor includes a casing, a screw rotor, an oil sump containing lubricant oil, a lubrication passage and a flow rate controller. The screw rotor is inserted in a cylinder portion of the casing to form a fluid chamber. The screw rotor rotates to suck a fluid into the fluid chamber for compression. The lubrication passage supplies the lubricant oil in the oil sump to the fluid chamber due to a difference in pressure between the oil sump and the fluid chamber. The flow rate controller reduces a flow rate of the lubricant oil supplied to the fluid chamber in accordance with a decrease in operating capacity of the screw compressor.

Screw compressor

A golf club shaft in which the isotropy of the prepregs configuring a torsion rigidity holding layer is high and in which sufficient torsional rigidity can be secured with fewer plies of fewer prepregs. The golf club shaft includes a torsional rigidity holding layer made of a thermosetting resin which contains reinforced fibers extending obliquely to a longitudinal direction of the shaft. The torsional rigidity holding layer includes a multilayer set prepreg, in which at least two layers of prepregs made of reinforced fibers are impregnated with a thermosetting resin. A plurality of prepregs in the multilayer set prepreg include reinforced fibers extending in mutually different directions. The multilayer set prepreg is continuously wound by at least two turns with the plurality of prepregs layered on each other. A golf club uses the shaft.

Golf club shaft and golf club using the same

A screw compressor includes a screw rotor, a casing, a low pressure space, a bypass passage and a slide valve. The screw rotor is provided with a plurality of helical grooves forming fluid chambers. The casing includes a cylinder portion with the screw rotor disposed in the cylinder portion. The low pressure space is formed in the casing to receive a flow of uncompressed, low pressure fluid. The bypass passage is opened in an inner peripheral surface of the cylinder portion to communicate the fluid chamber with the low pressure space. The slide valve is slideable in an axial direction of the screw rotor to change an area of an opening of the bypass passage in the inner peripheral surface of the cylinder portion. An end face of the slide valve facing the bypass passage is inclined along an extending direction of the helical grooves.

Screw compressor having slide valve with inclined end face

An apparatus for forming a hollow FRP article by internal pressure molding includes a vacuum chamber, a forming die positioned in the vacuum chamber, a vacuum-chamber opening/closing mechanism, a composite-body support device for supporting a composite body without making the composite body come into contact with the forming die in a state where the forming die is opened by the vacuum-chamber opening/closing mechanism, the composite body including an airtight internal-pressure holding tube and a prepreg fitted on said airtight internal-pressure holding tube, an evacuation system for evacuating the vacuum chamber, an internal-pressure supplying device for applying pressure to an inside of the internal-pressure holding tube, and a controller for actuating the vacuum-chamber opening/closing mechanism to clamp the forming die to thereby bring the forming die and the composite body into intimate contact with each other.

Method and apparatus for forming a hollow FRP article by internal pressure molding

It is object of the present invention to provide a golf club shaft superior in accuracy, minimizing a displacement between thermosetting resin layers, capable of obtaining a feeling close to the feeling of a steel shaft, and superior in stability. To solve the above problems, a golf club shaft of the present invention uses a golf club shaft comprising a torsional rigidity holding layer made of thermosetting resin including reinforcing fibers diagonally crossed in the longitudinal direction of said shaft and a UD flexural rigidity holding layer made of thermosetting resin including reinforcing fibers aligned in parallel to the longitudinal direction of said shaft, characterized in that at least a part of said torsional rigidity holding layer includes a plain weave fabric layer obtained by winding and curing like a shaft-shape a plain weave prepreg which lets a plain weave fabric having mutually woven warps and wefts impregnate with thermosetting resin in such a way that said warps and wefts are diagonally crossed in the longitudinal direction of said shaft.

Golf club shaft

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.

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.

Golf putter shaft

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.

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.

Method and apparatus for measuring torsional rigidity of a shaft

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. The invention is also directed to an apparatus for carrying out the above measuring method.

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Saitama, Japan

Norio Matsumoto