Patent ID: 9551395
Date: 2017-01-24
CPC Classifications: F16F

Claim:
1. A shock absorber comprising: an outer tube on in which a piston rod is mounted, and in which the piston rod is reciprocable in an axial direction, the piston rod having a projecting end projecting from a distal end of the outer tube; an inner tube rotatably mounted in the outer tube, the inner tube and the outer tube collectively forming a liquid accommodating chamber to which liquid is injected, the inner tube is provided with a plurality of communication holes arranged at intervals in a circumferential direction thereof, and formed so as to penetrate through the inner tube in a radial direction thereof; a rotative operating part provided at connected with the inner tube, the rotative operating part projecting from a base end of the outer tube; and a spring member disposed in the inner tube, the spring member applying a spring force to the piston rod in a projecting direction of the piston rod; wherein the inner surface of the outer tube has a contact surface and an eccentric surface having a curvature axis which is distant from a curvature axis of the contact surface, the curvature axis of the contact surface is aligned with a rotation central axis of the inner tube, and the contact surface of the outer tube is in contact with an outer peripheral surface of the inner tube, the eccentric surface of the outer tube and the outer peripheral surface of the inner tube collectively form a bypass channel which communicates with the communication holes, the bypass channel having a thickness reduced in a circumferential direction from the center part toward both ends thereof, and a communication opening degree of the bypass channel is changeable in a stepless manner and the communication hole is configured to be changed by rotating the inner tube and the communication holes with respect to the outer tube between a fully-opened state having a maximum value of the communication opening degree, and a closed state having a minimum value of the communication opening degree.