Abstract: In a double-sided engagement silent chain having inner link plates with inwardly protruding teeth, outermost link plates with outwardly protruding teeth, and outer link plates with outwardly protruding teeth, adjacent the outermost link plates, the plates are composed of a bainite and martensite mixed plate material. The bainite mixing ratio in the outermost link plates is higher than the bainite mixing ratio of the inner link plates and the adjacent outer link plates. The martensite mixing ratio of the inner link plates and of the adjacent outer link plates is higher than the martensite mixing ratio in the outermost link plates. The heights of the backs of the outermost link plates, measured from the tooth gap bottoms, are greater than the corresponding heights of the backs of the inner link plates, and may be equal to or greater than the heights of the backs of the adjacent outer tooth plates.

Abstract: Link plates of a silent chain are produced by first shaving the inner surfaces of the connecting pin holes, the sprocket tooth-engaging surfaces, and the backs of the link plates, and then forming dimples on those surfaces by shot-peening.

Abstract: In a double-sided engagement silent chain having inner link plates with inwardly protruding teeth, outermost link plates with outwardly protruding teeth, and outer link plates with outwardly protruding teeth, adjacent the outermost link plates, the plates are composed of a bainite and martensite mixed plate material. The bainite mixing ratio in the outermost link plates is higher than the bainite mixing ratio of the inner link plates and the adjacent outer link plates. The martensite mixing ratio of the inner link plates and of the adjacent outer link plates is higher than the martensite mixing ratio in the outermost link plates. The heights of the backs of the outermost link plates, measured from the tooth gap bottoms, are greater than the corresponding heights of the backs of the inner link plates, and may be equal to or greater than the heights of the backs of the adjacent outer tooth plates.

Abstract: Link plates of a silent chain are produced by first shaving the inner surfaces of the connecting pin holes, the sprocket tooth-engaging surfaces, and the backs of the link plates, and then forming dimples on those surfaces by shot-peening.

Abstract: In a roller chain, the outside diameters D of the rollers and the outside diameters d of the pins extending through bushings on which the rollers are disposed satisfy the relationships 0.72P?D?0.79P and 0.40P?d?0.44P where P is the pitch of the roller chain. The height H of the inner plates of the chain satisfies the relationship 0.96P?H. The elongation ratio of the chain is significantly reduced, and improvements in breaking strength of the pin and in the rotational fatigue of the chain are realized. Consequently wear resistance, strength, and endurance of the chain are significantly improved, making the chain suitable for use as a timing chain in an engine that rotates at high speed.

Abstract: In a roller chain, the outside diameters D of the rollers and the outside diameters d of the pins extending through bushings on which the rollers are disposed satisfy the relationships 0.72P≦D≦0.79P and 0.40P≦d≦0.44P where P is the pitch of the roller chain. The height H of the inner plates of the chain satisfies the relationship 0.96P≦H. The elongation ratio of the chain is significantly reduced, and improvements in breaking strength of the pin and in the rotational fatigue of the chain are realized. Consequently wear resistance, strength, and endurance of the chain are significantly improved, making the chain suitable for use as a timing chain in an engine that rotates at high speed.

Abstract: Three structural components jointly constituting a single guide link of a silent chain, i.e., two guide plates, at least one guide link plate disposed between the guide plates, and two round connector pins press-fitted in the guide plates are constructed to satisfy the expression (Pm+Dm−Dp′)−Pg′=0 where Pm is the link plate pitch represented by the distance between pin hole centers in the guide link plate, Dm is the inside diameter of the pin holes in the guide link plate, Dp′ is the outside diameter between the round connector pins press-fitted in each guide plate, and Pg′ is the post-press-fitting guide plate pitch represented by the distance between pin hole centers in each guide plate press-fitted with the round connector pins. In an assembled condition of the silent chain, each round connector pin extends straight with its outer peripheral surface being in contact with the inner peripheral surface of the mating pin hole of the guide link plate.

Abstract: To provide a silent chain that can restrict abrasion of connection pins and the bushings and can restrict the abrasive elongation of chain so as to be especially used for a diesel engine. A circularity of bushings used in the link assembly thereof is easily maintained. The silent chain includes: a guide plate; a link assembly having an inner link plate; a middle link plate; and a connection pin that connects them freely bendably. The bushings of the link assembly have no seam being made as solid type, and a plurality of concave areas for reserving oil are formed on surfaces of both end portions thereof. The notched concave areas have a depth that does not reach the inner link plate fixed to the bushing.

Abstract: Three structural components jointly constituting a single guide link of a silent chain, i.e.

Abstract: The housing of a ratchet tensioner is formed of an aluminum-containing metallic material in order to decrease the weight of the tensioner. A hard alumite layer having a thickness of 5 to 50 &mgr;m is formed on the inner circumferential surface of a plunger accommodation bore formed in the housing, and a lubricant is incorporated into the alumite layer. Thus, the service life before occurrence of seizure is increased.

Abstract: A chain tension relieving device which prevents excessive tension being applied to a tension run of a chain. A shoe (5C) engages a tension run (3B) of a chain (3) stretched between a driving sprocket (1) and a driven sprocket (2) from another side of the chain in a bowed portion of the chain (3). When the tension acting on the tension run (3B) is of a prescribed value or less, the shoe surface of the shoe (5C) is held to a given advanced position so as to bow the tension run of the chain (3) by a biasing force of mechanical tensioner (15D). When the tension exceeds the prescribed value, the tension side (3B) of the chain (3) is straightened against the biasing force of the mechanical tensioner and the shoe surface of the shoe (5C) retreats from the given advanced position.

Abstract: In order to provide a timing mark at a specific place on part of a timing chain in a manner in which the quality of the timing chain is maintained, a timing chain 4, made endless by outer plates 1 and inner plates 2 being connected by means of connecting pins 3 is provided with a timing mark 1' at a specific part on one side of an outer plate 1. The timing mark 1' is placed on the outer plate 1 between the connecting pins 3 and is in the shape of a web extending from an inner edge of the outer plate 1 to an outer edge thereof. The timing mark 1' is provided by baking a coating on the outer plate 1 after the timing chain has been assembled.

Abstract: For enhanced durability, a traveling guide shoe for a roller chain has a cross-sectional shape with a base slide guide surface 12 which engages only the bottoms of the side link plates of the chain on a chain-incoming-end, a projecting rolling guide surface 13 which engages only the rollers of the chain at an intermediate portion of the shoe. The base surface 12 and the projecting surface 13 are connected with each other through a continuous transfer surface 13.

Abstract: An oil tensioner includes a housing, forming a cylindrical bore therewithin, and a hollow cylindrical plunger. The housing and the plunger form an oil chamber therebetween, to which oil is supplied. The plunger is urged by a spring as well as external oil hydraulics. The plunger includes a screw groove, in communication with the oil chamber, formed on a sliding surface thereof abutting an inner surface of the housing. When the plunger is urged rearward, oil in the oil chamber flows gradually through the screw groove, thereby effectively lubricating the sliding surface therebetween.

Abstract: A vibration proofing system for an engine timing chain utilizes a tensioner on the slack side of the chain path, in which a ring-shaped, chain-engaging shoe is rotatably disposed on a circular frame mounted on the piston of a tensioner mechanism, and in which the shoe surrounds the frame and tensioner mechanism. Engine oil, which is used in the tensioner, is supplied from the tensioner to lubricate the rotatable chain-engaging shoe. On the tension side of the chain path, a guide includes fixed support, a first ring rotatable on the support, and a ring-shaped, chain-engaging shoe which is in off-centered relationship to the support and the inner diameter of which is larger than the outer diameter of the first ring. Engine oil is supplied through the support to lubricate the first ring.

Abstract: A vibration proofing system for an engine timing chain utilizes a tensioner on the slack side of the chain path, in which a ring-shaped, chain-engaging shoe is rotatably disposed on a circular frame mounted on the piston of a tensioner mechanism, and in which the shoe surrounds the frame and tensioner mechanism. Engine oil, which is used in the tensioner, is supplied from the tensioner to lubricate the rotatable chain-engaging shoe.

Abstract: In a machine, such as an internal combustion engine, in which a chain is used to transmit rotating power from one shaft to another, the chain is situated in an oil-tight chain compartment which is separated from other lubricant containing spaces so that lubricating oil in the other spaces cannot flow directly into the lubricating oil in the chain compartment. Contamination of the chain lubricant is avoided, and the useful life of the chain is increased. In a first embodiment, a separate quantity of oil is situated in the chain compartment. In a second embodiment, the chain lubricating oil is recirculated in the chain compartment by a dedicated pump. In a third embodiment, filtered engine oil is delivered to the chain compartment through a passage in a shaft, and through a port in a chain sprocket on the shaft.

Abstract: A tensioner lever for applying tension to an endless power transmission in the form of a chain, belt or the like, comprises an elongated arm made of aluminum and having I-shaped cross-sections in section planes transverse to its direction of elongation.

Abstract: A device for applying tension to an endless chain, belt or the like comprises a ratcheted plunger having a substantially planar face disposed in substantially perpendicular relationship to the axis of movement of the plunger, and a chain or belt-engaging lever having a pad with a convex face arranged to contact the substantially planar face of the plunger. Vibrational forces exerted by the lever on the tensioner are substantially parallel to the axis of movement of the plunger, so that wear of the plunger and plunger guide are significantly reduced.

Abstract: A tensioner lever for applying tension to an endless chain, belt or the like comprises an elongated arm and a plastic shoe, having at least one L-shaped element engaging both the back face and one side edge of the arm, at least one projection engaging the opposite side edge of the arm, and a U-shaped end hook engaging an end of the arm.