Nhk Spring Co., Ltd.

Fcc, LLC

Kenjiro Kawanabe

Takao Kobayashi

Tanehira Amano

Jun Tokumasu

Shigemasa Takahashi

Kazuo Ishii

Ichiro Sasuga

Yutaka Nishida

Kazuhiro Itonaga

A tensioner comprises shaft members that mate with each other by way of thread portions. A first shaft member is rotatable with respect to a casing and is restrained from moving in its axial direction. A second shaft member, which is restrained from rotating with respect to the casing, is movable in its axial direction. A torsion spring applies torque in a first direction to the first shaft member. A torque switching member, which can switch frictional torque in association with the rotation of the first shaft member, is provided between the first shaft member and the casing.

Tensioner for applying tension to force transmitting member

A compression coil spring is used as a return spring which is stored in the housing of a clutch to urge the clutch piston in its returning direction. The effective number of turns of the compression coil spring is two or less, and the number of turns at an end-turn portion thereof is more than 0.45 and not more than 0.7. The compression coil spring is used in the compressed state throughout the operating stroke of the clutch piston. The number of turns at the end-turn portion is desirably within the range of 0.5 to 0.65, more desirably within the range of 0.55 to 0.62.

Return spring for clutch

Growing community of inventors

Higashiharutika-Ina, Japan

Kenjiro Kawanabe