Abstract: A tension measuring apparatus and method for a chain by which tension applied to the chain is correctly and reproducibly measured is disclosed and claimed. A tension measuring method for a chain (10) comprising a pair of right and left inner plates (11), bushes (12) press-fit between the inner plates (11), a pair of right and left outer plates (13) disposed on both outsides of the inner plates (11), connecting pins (14) loosely inserted into the bush (12) and press-fit between the outer plates (13), and connected to each other characterized in that a strain gauge is applied to a position having a relation of a ratio of 1 to 1 between tension applied to the chain and an output of the strain gauge (16).

Abstract: A tension measuring apparatus and method for a chain by which tension applied to the chain is correctly and reproducibly measured is disclosed and claimed. A tension measuring method for a chain (10) comprising a pair of right and left inner plates (11), bushes (12) press-fit between the inner plates (11), a pair of right and left outer plates (13) disposed on both outsides of the inner plates (11), connecting pins (14) loosely inserted into the bush (12) and press-fit between the outer plates (13), and connected to each other characterized in that a strain gauge is applied to a position having a relation of a ratio of 1 to 1 between tension applied to the chain and an output of the strain gauge (16).

Abstract: A rolled product for a chain and a method for producing the rolled product are disclosed. Plural dimples are formed in a zigzag pattern in at least one of inner and outer peripheral surfaces of the rolled product, the dimples absorbing plastic deformation of a rolled workpiece when the rolled product is forced through a circular orifice of a die, and plural recessed portions are defined by the dimples on any imaginary straight line on the dimpled surface in the axial direction of the rolled product. The absorption of plastic flow by the dimples prevents a waving phenomenon from occurring at the end faces of the rolled product. When the rolled product is used as a chain component such as bushing or roller, it is possible to prevent leakage of a lubricant in the axial direction of the rolled product, and hence possible to improve the lubricant retaining performance in a rotating and sliding portion.

Abstract: A rolled product for a chain and a method for producing the rolled product are disclosed. Plural dimples are formed zigzag in at least one of inner and outer peripheral surfaces of the rolled product, the dimples being formed for absorbing a plastic deformation of a rolled workpiece when forced through a circular orifice of a die, and plural recessed portions are defined by the dimples on any imaginary straight line in the axial direction of the rolled product. A waving phenomenon does not occur at end faces of the rolled product. When the rolled product is used as a chain component such as bushing or roller, it is possible to prevent leakage of a lubricant in the axial direction of the rolled product and hence possible to improve the lubricant retaining performance in a rotating and sliding portion.

Abstract: A low-noise chain member comprises a bushing, a roller and oil grooves in which a wedge or squeeze effect of a lubricating oil, which is interposed between the bushing and the roller, is effective in reducing noise. The oil grooves are provided on at least one of the outer surface of the bushing and the inner face of the roller. The inner face of the roller is formed with a curved surface so as to conform to the contour of a curved outer surface of the bushing. A clearance between the inner face of the roller and the outer surface of the bushing is not widened around both ends of the roller. Only a small amount of the lubricating oil between the roller and the bushing escapes to the outside, of the roller and bushing, so that a fluid lubricating state between the bushing and the roller is maintained.

Abstract: A barrel-shaped coil spring roller is formed by closely winding spring wire rods having fine crepe-like concave-convex surfaces on the surface of the barrel-shaped coil spring roller. The fine crepe-like concave-convex surfaces serve as a lubricating oil reservoir and are formed by a shotpeening process. Lubricating oil is retained on the fine crepe-like concave-convex surfaces formed by the shot-peening process. Sliding noises between the spring wire rods adjacent to each other, which noises are generated by elastic deformation of the barrel-like coil spring roller when in engagement with the toothed surface of the sprocket, are reduced by the lubricating oil. The wear on both of the barrel-shaped coil spring roller and the sprocket is lessened and the power loss is reduced. The low noise chain is capable of retaining a lubricating oil on the surface of spring wire rods of a barrel-shaped coil spring roller for long periods of time, while still maintaining a noise reduction effect.

Abstract: The present invention improves accuracy in the axial dimension of rolled parts for a chain such as bushings, rollers and similar. A rolled part is manufactured by cutting a strip of steel into a rectangular shape to obtain a rectangular base material having a predetermined dimension, The rectangular base material is rolled into a clindrical shape to obtain a cylindrically formed part having cut end surfaces face each other. A core is inserted for rolling the rectangular base material into the cylindrically formed part. The cylindrically formed part is then pressed through a die having a circular opening. The rolled part has a plurality of blind grooves on a surface thereof. While the cylindrically formed part is being pressed through the die having a circular opening, a plastic flow of the material of the cylindrically formed part intensively occurs in a direction toward the blind grooves.

Abstract: Elongation of a moving endless body, such as a chain, a belt, a conveyor or the like, is measured continuously by providing two indices, e.g. pins or tongues, on the endless body, and two sensors, e.g. magnetic or optical sensors, along the path of circulating movement of the endless body. The sensors are connected to an arithmetic circuit which determines elongation from the data provided by the sensors.