Abstract: A torsional damper comprises a pulley hub fixed to a rotary shaft such as the crank shaft of an engine or the like, and a damper mass fixed, by means of a damping rubber, in a cavity formed in the front portion of the pulley hub. A projection is provided on the outer circumference of the damper mass, and a groove is formed in the pulley hub oppositely to the projection to receive a part of the projection.

Abstract: An electromagnetic coupling selectively transmits power from an automobile engine to a supercharger. The electromagnetic coupling includes a rotor having excitation coils thereon and rotatable by the drive source, an armature magnetically attractable in a direction toward the rotor for rotation therewith in response to energization of the excitation coils, an outer holder plate mounted on the armature and having a first flange, an inner holder plate connected to the supercharger and disposed radially inwardly of the outer holder plate, the inner holder plate having a second flange positioned concentrically with and spaced from the first flange, and an elastomeric member disposed between and joined to the first and second flanges. The elastomeric member has a thickness in the direction toward the rotor which is progressively increased from the second flange toward the first flange.

Abstract: An elastomeric shock and vibration isolator having a ring shaped rubber member in which a space is formed or a ring shaped rubber member having within such an internal space a sealed gas chamber and two liquid chambers filled with liquid which are interconnected through an orifice has a tightening ring on the outer circumference of the ring shaped member. The tightening ring is adjustable to adjust the tightening force against the ring shaped rubber member. The characteristics of a thus constructed elastomeric shock and vibration isolator can be changed to correspond to the position and condition of utilization.

Abstract: A pneumatic marine fender composed of a cylindrical barrel serving as a shock receiving face, which comprises a composite inner reinforcement composed of two kinds of cord layers which consist of an axially extending cord layer and a circumferentially extending cord layer whose cords are slightly inclined and symmetrically arranged with respect to the circumferential line of the cylindrical shell in reverse directions and helically wound around the cylindrical shell.