Tsubakimoto Chain Company

Nobuyuki Fujimoto

Hiroki Ishida

Masao Maruyama

Yoshiaki Sugimoto

Toshihiro Hosokawa

Makoto Kanehira

Hitoshi Ohara

Masaru Morimoto

Masahiro Sato

Yutaka Uchiumi

Tadasu Suzuki

Takayuki Funamoto

Yoshio Kurokawa

Takero Nakagawa

Shuji Sasamoto

Hiroshi Hashimoto

Katsuya Nakakubo

Tsutomu Namie

Masaaki Matsumoto

Takahiro Matsushita

Kouji Katou

Haruo Sugita

Shintarou Yoshimoto

Koichi Kaihotsu

In a tensioner for a timing chain, a spring-biased plunger for urging a shoe into sliding engagement with the chain is temporarily held in a retracted condition, prior to installation of the tensioner, by a stopper having a pin that extends through a hole in the tensioner housing and engages a grove formed in the plunger. The stopper is bent so that its handle extends away form the pin axis at an angle greater than zero but not greater than 90&#xb0;. Removal of the stopper from the tensioner can be carried out by rotating the handle to avoid interference with engine components in the vicinity of the tensioner.

Tensioner with improved stopper

In a hydraulic tensioner having a relief valve mechanism in which a spring-biased valve element is reciprocable in a bore, hitting sounds produced by collision of the relief valve element with a plug in the bore, and wear and breakage of the biasing spring, are prevented by providing an oil relief hole in a peripheral wall of the relief valve bore at a position where it is closed by the relief valve element when he relief valve element is moved by a rapid increase in oil pressure.

Hydraulic tensioner with relief valve mechanism

A plunger equipped with a relief valve mechanism is slidably mounted in a tensioner housing. The relief valve mechanism has a valve spring disposed between a valve and a spring retainer plug in a compressed condition. The spring retainer plug has a stopper surface formed on the side which opposes the valve. The maximum displacement of the valve and the maximum amount of compression of the valve spring are defined by the stopper surface so that the maximum shear stress acting in a wire of the valve spring is less than a fatigue limit of the valve spring wire.

Tensioner with relief valve mechanism

A hydraulic tensioner includes a relief valve provided at a projecting end portion of a plunger. The relief valve has a pressure path communicating with a high pressure oil chamber, a valve body fitted for sliding movement in the pressure path, a spring for normally biasing the valve toward the high pressure oil chamber, and an outlet port communicating, when the valve body is moved back against the force of the spring, with the pressure path. The valve body is formed as a unitary member including a slidably movable portion fitted for sliding movement in the pressure path and acted upon by a hydraulic pressure of the high pressure oil chamber, and a flange portion having a cross sectional area greater than that of the slidably movable portion for being acted upon by the force of the spring.

Hydraulic tensioner with relief valve

A hydraulic tensioner includes a relief valve mechanism assembled in a plunger and held in fluid communication with a high-pressure oil chamber defined between a housing and the plunger which is slidably inserted in a plunger accommodation bore in the housing with a tip portion projecting therefrom. The relief valve mechanism is composed of a cup-shaped orifice member having an orifice formed in an outer circumferential surface thereof, and a relief valve assembled in the cup-shaped orifice member. The relief valve includes a cup-shaped sleeve slidably received in the orifice member, a spring urging the sleeve toward the high-pressure chamber, and a discharge port normally closed by the sleeve and adapted to be opened when the sleeve is displaced against the force of the spring. The thus constructed relief valve mechanism is small in size and capable of achieving downsizing of the hydraulic tensioner.

Hydraulic tensioner

A silent chain has a plurality of interconnected plates adapted for operative engagement with toothed surfaces of a sprocket. Each of the plates has flank surface portions and crotch surface portions, with the crotch surface portions having protruding portions. The protruding portions of the crotch surface portions make contact with the toothed surfaces of the sprocket at the beginning of engagement of each plate with the sprocket and are spaced away from the toothed surfaces of the sprocket at least during engagement of the flank surface portions with toothed surfaces of the sprocket.

Plate for a silent chain having a protruding portion for reducing the

A plate for a silent chain has a side punched into a forked shape for engagement with a sprocket. The forked side of the plate has inner engaging surfaces opposing each other, outer engaging surfaces, and an arcuate leg-side end surface connecting the inner engaging surfaces. The leg-side end surface, on which stress is likely to be concentrated, has a shear face tissue along at least 70% of the thickness of the plate. A silent chain having such a plate has a high plate fatigue strength and enhanced durability and reliability, and can be manufactured at a low cost.

Plate for a silent chain

A silent chain, as well as a rocker pin and a plate of the silent chain, are provided which are capable of enhancing the transmission efficiency, and improving the fatigue strength of the plate to thereby prolong the service life of the silent chain. Rocker pins are inserted into the pin holes of each plate of a plurality of plates of a silent chain. The rocker pins are located closer to outer ends of the plate and are formed with generally flat plate abutting surfaces. The plate abutting surfaces are received by generally flat pin seating surfaces of the pin holes, respectively, to surely prevent rotation of the rocker pins relative to the pin holes. Further, in addition to the generally flat pin seating surfaces, generally flat and short continuous surfaces are formed centrally up and down of each pin hole. Thus, stress concentration on the plate is diminished and the fatigue strength of the plate is improved.

Silent chain, and rocker pin and plate thereof

A silent chain is provided in which a plurality of link plates of a certin configuration may have an identification indicator marked on a reference surface thereof at the time connecting pin inserting holes are punched into the link plates in order to ensure the link plates are properly directed in the same direction, are superposed on the connecting pins, and are constituted in a chain-like manner by the connecting pins so that meshing surfaces of the link plates mesh smoothly to prevent any meshing noise.

Silent chain

A frictional transmission chain drive for use between V-groove pulleys comprises a series of C-shaped chain struts and friction force struts superposed along the length of an endless transmission chain. The chain struts are fitted in grooves located across link plates of the chain, with their open ends alternately located on opposite sides of the transmission chain. The friction force struts are provided with recesses which grip the chain to prevent sideways movement of the struts relative to the chain. The friction force struts on opposite sides of a chain strut can have their open ends on the same said of the chain as the open end of the chain strut, or, alternatively, can have their open ends on the side of the chain opposite the side on which the open end of the chain strut is located.

Frictional transmission chain

Noise reduction in a silent chain is achieved by forming the majority of the toothed link plates with modified tooth profiles having a circular concave portion conforming t the shape of the teeth of the sprocket engaged by the chain, and a circular convex portion near the tip, the center of curvature of the convex portion being on the dedendum side of the pitch line. Additional link plates having a different meshing pitch are disposed at irregular intervals along the length of the chain. These additional link plates can have linear of modified tooth profiles.

Silent chain having improved noise reduction

In a rocker pin type friction transmission chain, the engaged surfaces of the rocker pins and pin insertion holes in the link plates are in the form of parts of an ellipse which are symmetrical with respect to the minor axis of the ellipse. This configuration is easy to machine, prevents relative rotation of the pins and the link plates, avoids cracking of the link plates due to concentrations of loads, and reduces the likelihood of fatigue failure due to excessive pressures exerted by the pins and link plates on each other.

Rocker pin type friction transmission chain

A rocker-pin type continuously variable transmission chain having a plurality of link plates connected endlessly by rocker pins which project into pin insertion holes formed in the link plates. Each pin insertion hole defines thereon a side load transmitting surface which engages an opposed side load transmitting surface on the rocker pin. These load transmitting surfaces on the rocker pin and hole have opposed center surface portions which are maintained free of contact with one another. A pair of concave surface portions are smoothly joined directly to opposite ends of the center surface portion of the hole, and project outwardly in opposite directions therefrom. A similar pair of convex surface portions are formed on the rocker pin, and are joined to opposite ends of the center surface portion thereof and project outwardly therefrom. The concave and convex surface portions are defined generally as partial elliptic surfaces which are generated about and symmetrically disposed with respect to a major axis of an ellipse, which major axis extend centrally of the bore in the lengthwise or longitudinal direction of the link plate. The elliptically shaped concave and convex surfaces directly engagingly contact one another, and create a wedge-like configuration which prevents rotation of the rocker pin relative to the bore, and provides for uniform load transmission over the extensive surface areas defined by the contacting convex and concave surface portions.

Rocker-pin type friction gearing chain

A rocker-joint silent chain in which the pin insertion holes for each link have rocker-joint connecting pin means extending therethrough. Each pin insertion hole has two opposed, spaced-apart surfaces each having the cross-section form of arcs of uniform radius. The centers of curvature of said two surfaces are offset from one another so that they define an arcuate, but noncircular, cavity which is effective to wedge said connecting pin in load-transmitting relationship to its associated link when the chain is driven.

An endless belt, for use in a variable speed transmission comprising at least one pulley having opposed conical surfaces, comprises a loop-shaped stack of I-shaped friction plates having left and right recesses, with chains located in the recesses in side-by-side relationship. Each chain comprises interleaved link plates, and the chains are out of phase with each other by one-half the pitch distance. Each friction plate is engaged, in driving relationship, in notches in the link plates of one of the two chains, and the next friction plate is engaged, in driving relationship, in notches of the link plates of the other chain. There are no friction plates which are not engaged in notches of the link plates. Consequently less pressure and improved friction are achieved. The preferred link plate comprises two separable layers formed by stamping. In one preferred embodiment, the chains comprise interleaved groups of link plates of uniform thickness, and each group consists of the same number of link plates.

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Hanno, Japan

Nobuyuki Fujimoto