Abstract: A tester for measuring a durability of a knitted yarn portion in which at least two sets of yarns, including a set of first yarns and a set of second yarns, are intersected, the tester includes: a first holding unit holding ends of the two sets of yarns at first positions that are relative to the knitted yarn portion; a second holding unit holding opposite ends of the two sets of yarns at second positions that are relative to the knitted yarn portion; and a position adjusting unit, connected to the first holding unit and the second holding unit, allowing at least one of the first positions and the second positions, relative to the knitted yarn portion, to be moved to other positions, thus varying an intersecting angle of the yarns of the knitted yarn portion.

Abstract: A lightweight damper pulley is provided which can be produced in a simple manner. The damper pulley includes a central portion, a belt retaining portion made of metal plate, and a ring-shaped rubber or elastic member placed therebetween. The central portion includes a cylindrical boss portion to be fixed onto a rotary shaft, a main portion extending radially outwardly from the larger diameter area of the cylindrical boss portion, and a flange bent horizontally from an outer periphery of the main portion. The central portion is integrally formed from a metal plate by press-forming or the like. The flange and the belt retaining portion can have projections which compress the rubber or elastic member to hold it securely in place.

Abstract: A pulley is made from a metal plate which is easy to manufacture, inexpensive in manufacturing cost, light weight and sufficient strength by using a press forming technique. The pulley has a thin tubular boss portion and a disk shaped body portion which are integral. The boss portion may have a reinforcing flange at one open end portion. The reinforcing flange aids in providing sufficient strength against the tightening force of a nut which is screwed onto a shaft inserted into the boss portion, and also disperses the tightening force. Further, the pulley may have formed integrally on the boss portion a key member.

Abstract: A method for producing a damper pulley having a boss portion to be press-fitted onto a rotary shaft, an annular main portion extending from the boss portion, a flange portion formed along an outer periphery of the main portion, a ring-shaped damper-mass member located outside the flange portion and a rubber body interposed between the flange portion and the damper-mass member includes the steps of integrally forming the boss portion, the main portion and the flange portion of a metallic plate such that the main portion has a curved section, and has a radial length greater than a straight line distance between the boss portion and the flange portion, placing the rubber body between the flange portion and the damper-mass member, and enlarging the diameter of the flange portion to elongate the main portion having a curved section, thereby the enlarged flange portion presses the rubber body against the damper-mass member.

Abstract: A pulley formed of resin having improved strength. The pulley includes a central body formed from a synthetic resin material. The main body has a belt-retaining portion along the outer peripheral surface thereof. A boss made of a metallic cylindrical body is embedded in the axial center of the main body. The boss is adapted to be secured to a rotary shaft. A plate-shaped metallic insert extends from an outer periphery of the boss to the interior of the main body. A plurality of service holes are formed in the insert, as is at least one engaging hole. The engaging hole is filled with the same synthetic resin material as the central body is formed of.

Abstract: The disclosure relates to a damper pulley that exhibits a good damping effect and has a preferable resonance ratio. An annular damper-mass member is joined to an annular surface of a plate portion of a pulley through a first resilient rubber member. Two fan-like concave portions are formed in the surface of the annular damper-mass member, which faces the annular surface of the plate portion, at symmetrical positions with respect to the center of rotation of the pulley. Two projections are formed on the annular surface of the plate portion so as to perpendicularly project into the fan-like concave portions. A second resilient rubber member is interposed between each concave portion and projection. When torsional vibrations are exerted, each second resilient rubber member produces compression deformation, thereby generating a large spring force, whereby the resonance frequency against the torsional vibrations sufficiently increases even when the inertia moment of the mass member is increased.