Abstract: An object is to prevent a loss in sprocket drive efficiency and chain slacking. The chain includes a plurality of inner link plates, a plurality of outer link plates, and a plurality of pins. At least any of the plurality of inner link plates, outer link plates, or pins include a hardened surface layer on part or all of sliding surfaces that slide against other components, the hardened surface layer containing one of Cr carbide, Ti carbide, V carbide, Nb carbide, Cr nitride, Ti nitride, V nitride, and Nb nitride.

Abstract: The invention provides a simple-structured tensioner lever capable of suppressing deflection of a stopper member and allows smooth assembly of the tensioner lever into an engine. The tensioner lever includes a stopper member for locking a coil spring, this stopper member including: a stopper pin portion inserted into a pin hole; a stopper front side extension portion continuous with one end of the stopper pin portion and protruding toward a base front surface; a stopper rear side extension portion continuous with the other end of the stopper pin portion and protruding toward a base rear surface; a spring lock portion formed in the stopper rear side extension portion and making engagement with a spring support arm; and a stopper movement restricting portion making engagement with the spring support arm to restrict movement of the spring support arm in a direction away from the base rear surface.

Abstract: The invention provides a simple-structured tensioner lever capable of suppressing deflection of a stopper member and allows smooth assembly of the tensioner lever into an engine. The tensioner lever includes a stopper member for locking a coil spring, this stopper member including: a stopper pin portion inserted into a pin hole; a stopper front side extension portion continuous with one end of the stopper pin portion and protruding toward a base front surface; a stopper rear side extension portion continuous with the other end of the stopper pin portion and protruding toward a base rear surface; a spring lock portion formed in the stopper rear side extension portion and making engagement with a spring support arm; and a stopper movement restricting portion making engagement with the spring support arm to restrict movement of the spring support arm in a direction away from the base rear surface.

Abstract: There is provided a ratchet-type tensioner whose spring stopping washer for seating a ratchet biasing spring is rigidly and readily assembled to a ratchet-receiving hole so as not to fall out of the ratchet-receiving hole and which reduces flapping noise and prevents seizure of the plunger by securely and stably operating a ratchet mechanism in operating an engine. The ratchet-type tensioner 100 is arranged so that the spring stopping washer has a C-ring anchored in the rear-end area of the ratchet-receiving hole by fitting in a diameter-reduced state and by enlarging its diameter within an anchoring circumferential groove of the ratchet-receiving hole and a spring stopping piece extended from the C-ring to a ring center area to seat the ratchet biasing spring.

Abstract: In a pivoted tensioner lever extending upward from a pivot axis, both ends of boss through which a pivot shaft extends are provided with funnel-shaped grooves that guide oil adhering to the lever body into a region between the shaft and the inside of the boss. Oil guiding walls, continuous with the boss, and downwardly sloping reinforcing ribs with oil passages formed at their lower ends, increase flow of oil adhering to the lever body to the region between the shaft and the inside of the boss.

Abstract: In a transmission chain having link plates with convex edges for sliding contact with a guide surface, the plates are asymmetric in shape so that the distance from a line connecting the centers of the connecting holes and the convex edge is greatest at a position other than at the midpoint between the connecting holes. A pivoting action of the link plates takes place as they slide over a guide surface, changing the abutment point.

Abstract: There is provided a ratchet-type tensioner whose spring stopping washer for seating a ratchet biasing spring is rigidly and readily assembled to a ratchet-receiving hole so as not to fall out of the ratchet-receiving hole and which reduces flapping noise and prevents seizure of the plunger by securely and stably operating a ratchet mechanism in operating an engine. The ratchet-type tensioner 100 is arranged so that the spring stopping washer has a C-ring anchored in the rear-end area of the ratchet-receiving hole by fitting in a diameter-reduced state and by enlarging its diameter within an anchoring circumferential groove of the ratchet-receiving hole and a spring stopping piece extended from the C-ring to a ring center area to seat the ratchet biasing spring.

Abstract: In a chain transmission, the guide-contacting portions of inner and outer plates of a chain each comprise a pair of front and rear flat surfaces, an intermediate concave oil-retaining surface and convex connecting surfaces. The lengths of the flat surfaces are such that adjacent flat surfaces of overlapping inner and outer plates overlap even when the plates in contact with the portion of a convex guide surface having the smallest radius of curvature.

Abstract: In a sliding contact chain guide of the kind used in the timing transmission of an internal combustion engine, the back of the guide shoe, which engages a metal guide base, is formed with two, spaced longitudinal ribs, having between them a set of ribs formed in a lattice. The longitudinal ribs are wider than the ribs of the lattice.

Abstract: In a silent chain transmission, a silent chain composed of uniform link plates meshes with a sprocket having two or three kinds of teeth randomly distributed around its circumference. The teeth have a common tooth gap bottom diameter, and a uniform angular spacing, but have different heights and different tooth forms.

Abstract: In a transmission chain having link plates with convex edges for sliding contact with a guide surface, the plates are asymmetric in shape so that the distance from a line connecting the centers of the connecting holes and the convex edge is greatest at a position other than at the midpoint between the connecting holes. A pivoting action of the link plates takes place as they slide over a guide surface, changing the abutment point.

Abstract: In the check valve of a hydraulic tensioner, a bell-shaped retainer is provided with plural, branched, leg portions which resiliently grip the outer surface of a ball seat. Oil induction slots are formed between adjacent branched leg portions of the retainer to provide oil flow paths that are unimpeded by the plunger-biasing spring of the tensioner.

Abstract: In a hydraulic tensioner having a hollow plunger that cooperates with a housing to form a high pressure oil chamber, the movable element of the check valve that allows oil to flow into the high pressure oil chamber is a bar-like element that extends into a coiled plunger-biasing spring and is biased into engagement with a valve seat by another coiled valve-biasing spring that extends into the plunger-biasing spring. The bar-like element has a larger diameter portion the diameter of which is slightly less than the inner diameter of the plunger-biasing spring, and a smaller diameter portion the diameter of which is slightly less than the inner diameter of the valve-biasing spring. The valve-biasing spring bears against a shoulder at the location at which the smaller and larger-diameter portions of the bar-like element meet.

Abstract: In a chain transmission, the guide-contacting portions of inner and outer plates of a chain each comprise a pair of front and rear flat surfaces, an intermediate concave oil-retaining surface and convex connecting surfaces. The lengths of the flat surfaces are such that adjacent flat surfaces of overlapping inner and outer plates overlap even when the plates in contact with the portion of a convex guide surface having the smallest radius of curvature.

Abstract: In a silent chain, a link plate is formed by punching, followed by simultaneous shearing of the inner surfaces of the pin holes, the inner engagement surfaces of the teeth, the outer engagement surfaces of the teeth, the connecting arc continuous with the inner connecting surfaces, and the back of the link plate over at least 70% of the plate thickness. The plates are arranged at random to form a link, and engage a sprocket first by engagement of an inner engagement surface with a sprocket tooth, and thereafter seat on the sprocket with outer engagement surfaces of the link teeth in engagement with the sprocket teeth.

Abstract: In a pivoted tensioner lever extending upward from a pivot axis, both ends of boss through which a pivot shaft extends are provided with funnel-shaped grooves that guide oil adhering to the lever body into a region between the shaft and the inside of the boss.

Abstract: In a silent chain transmission, a silent chain composed of uniform link plates meshes with a sprocket having two or three kinds of teeth randomly distributed around its circumference. The teeth have a common tooth gap bottom diameter, and a uniform angular spacing, but have different heights and different tooth forms.

Abstract: In the check valve of a hydraulic tensioner, a bell-shaped retainer is provided with plural, branched, leg portions which resiliently grip the outer surface of a ball seat. Oil induction slots are formed between adjacent branched leg portions of the retainer to provide oil flow paths that are unimpeded by the plunger-biasing spring of the tensioner.

Abstract: In a sprocket for a roller chain, the tooth form is such that the distance between the tooth center line and a part of the front tooth surface, at a location on the tooth head side of the pitch line, is greater than the distance between the tooth center line and the front surface of the tooth along the pitch line. The diameter of the tooth gap bottom circle is smaller than the diameter of a tooth gap bottom circle in a sprocket having an ISO tooth form for the same chain.

Abstract: In a sliding contact chain guide of the kind used in the timing transmission of an internal combustion engine, the back of the guide shoe, which engages a metal guide base, is formed with two, spaced longitudinal ribs, having between them a set of ribs formed in a lattice. The longitudinal ribs are wider than the ribs of the lattice.