Abstract: In an engine timing chain guide composed of a synthetic resin shoe supported on a frame by L-shaped and strip-shaped engagement members integrally molded as unitary parts of the shoe, the L-shaped members are formed with oblique tongues that resiliently engage side edges of the frame member, and the strip-shaped engagement members include surfaces that extend obliquely toward, and resiliently engage, a side edge of the frame member. Laterally extending legs of the L-shaped members are also formed with bulged portions, and the frame member is sandwiched between the bulged portions and a back side of the shoe.

Abstract: In an engine timing chain guide composed of a synthetic resin shoe supported on a frame by L-shaped and strip-shaped engagement members integrally molded as unitary parts of the shoe, the L-shaped members are formed with oblique tongues that resiliently engage side edges of the frame member, and the strip-shaped engagement members include surfaces that extend obliquely toward, and resiliently engage, a side edge of the frame member. Laterally extending legs of the L-shaped members are also formed with bulged portions, and the frame member is sandwiched between the bulged portions and a back side of the shoe.

Abstract: In a tensioner lever assembly for a chain transmission, an auxiliary lever, arranged to pivot relative to a main tensioner lever, engages a free span of the chain approaching the main lever from a driving sprocket. The auxiliary lever can be pivoted coaxially with the main lever, and can extend either toward the center of the main lever, or toward the driving sprocket. Alternatively, the auxiliary lever can be pivoted on the main lever at a location remote from the pivot axis of the main lever, and engaged with a free span of the chain moving away from the main tensioner lever and approaching a driven sprocket.

Abstract: In a chain transmission a standard ISO roller chain meshes with a modified sprocket having a root diameter larger than the root diameter of a standard sprocket designed for use with the standard chain. The angular tooth pitches can be either of two kinds. In a first version, the sprocket has two irregularly distributed tooth pitches, ???? and ?+2??, there being two tooth pitches ???? for each tooth pitch ?+2??. In a second version, the sprocket has three angular tooth pitches, ????, ?, and ?+??, in equal numbers, also distributed irregularly.

Abstract: A chain transmission comprises a composite chain having a set of sprocket-engaging rollers disposed between sets of link plates having sprocket-engaging teeth, and a sprocket having three sets of sprocket teeth. As the chain approaches the sprocket, a rear flank of a link plate tooth first comes into contact with a sprocket tooth, and slides thereon. However, as the rollers become seated, the flanks of the link plate teeth become separated from the sprocket teeth.

Abstract: In a chain transmission incorporating a standard roller chain, the diameter of the tooth gap bottom circle of a sprocket in mesh with the chain, is greater than the diameter of the tooth gap bottom circle for a corresponding sprocket having an ISO tooth form.

Abstract: In a pivoting guide for a traveling transmission chain, composed of a synthetic resin body having a shoe and a slotted reinforcement, and a plate fitting into the slot, the plate has a mounting hole received on a boss formed on the guide body and coaxial with a mounting hole on the guide body which receives a pivot shaft. This structure facilitates assembly and mounting because the plate is securely attached to the guide body before the assembly is mounted. The plate does not contact the pivot shaft, and therefore full advantage is taken of the self-lubricating property of the synthetic resin. The boss may be elongated so that the length of the mounting hole of the guide body is greater than the width of the shoe so that wear in of the guide body due to biased loads is dispersed, and the useful life of the guide is extended.

Abstract: A guide for an engine timing chain comprises a shoe mounted on a guide body, and having opposed, chain-restricting, side walls integrally molded with a chain-contacting shoe bottom. Each wall comprise a low portion, and an outwardly stepped high portion. The height of the low portion less than the distance between the connecting pins of the chain and the chain-contacting surface of the shoe bottom. The height of the high portion, however, is greater than the distance between the connecting pins and the chain-contacting surface. The high portion of each wall is stepped outward sufficiently to provide a clearance between the end of a connecting pin and the inwardly facing side of the high portion when the adjacent outer link plate of the chain is in contact with the corresponding low portion. The height of the high portion, however is greater than the overall height of the timing chain.

Abstract: In a tensioner lever assembly for a chain transmission, an auxiliary lever, arranged to pivot relative to a main tensioner lever, engages a free span of the chain approaching the main lever from a driving sprocket. The auxiliary lever can be pivoted coaxially with the main lever, and can extend either toward the center of the main lever, or toward the driving sprocket. Alternatively, the auxiliary lever can be pivoted on the main lever at a location remote from the pivot axis of the main lever, and engaged with a free span of the chain moving away from the main tensioner lever and approaching a driven sprocket.

Abstract: In a ratchet-type hydraulic tensioner for a chain transmission, having a plunger and a housing forming a high pressure oil chamber, an excess supply oil discharge passage is provided. The discharge passage communicates with an oil supply passage leading from an oil supply opening, which receives oil under pressure from a oil pump, to a hydraulic check valve mechanism in the housing, which delivers oil to the high pressure oil chamber. Excess oil is discharged to the exterior of the tensioner housing and directed toward the chain. Excessive chain tension is avoided, and smooth and reliable chain travel, and suppression of whistling sounds, are achieved.

Abstract: A plastic movable guide for a chain or other traveling transmission medium, comprises a guide body composed of a shoe and a slotted plate-receiving portion integrally molded as a unit from a resin, and a reinforcing plate inserted into the slot. A mounting hole adjacent one end of the guide body is aligned with a hole adjacent one end of the reinforcing plate. The diameter of the hole in the reinforcing plate is larger than the diameter of the mounting hole in the guide body, so that the inner periphery of the hole in the reinforcing plate does not extend inward past the edge of the mounting hole. The guide so configured exhibits excellent quietness and assembly efficiency and can be produced at a relatively low cost.

Abstract: In a pivoting guide for a traveling transmission chain, composed of a synthetic resin body having a shoe and a slotted reinforcement, and a plate fitting into the slot, the plate has a mounting hole received on a boss formed on the guide body and coaxial with a mounting hole on the guide body which receives a pivot shaft. This structure facilitates assembly and mounting because the plate is securely attached to the guide body before the assembly is mounted. The plate does not contact the pivot shaft, and therefore full advantage is taken of the self-lubricating property of the synthetic resin. The boss may be elongated so that the length of the mounting hole of the guide body is greater than the width of the shoe so that wear in of the guide body due to biased loads is dispersed, and the useful life of the guide is extended.

Abstract: The present invention relates to a hydraulic type tensioner with a relief valve. In this tensioner, a relief valve, which is opened and closed in accordance with the oil pressure of oil supplied under pressure from an oil pressure generating source such as an oil pump or the like through an oil supply port, is provided in a bypass oil path, which detours a check valve mechanism formed in a tensioner body and communicates between the oil supply port and a high pressure oil chamber.

Abstract: A plastic movable guide for a belt or chain transmission has a plunger-engaging portion for contact with the plunger of a tensioner at a location remote from its pivot axis. A reinforcing plate is located in a slot in a resin guide body, and is slightly recessed at the location of the plunger-engaging portion so that it does not protrude from the slot opening and is not contacted by the plunger of the tensioner. Superior quietness of operation, ease of assembly, and reduction of production cost are achieved.

Abstract: A ratchet tensioner includes a mechanism for selectively locking and releasing a plunger with respect to a ratchet pawl. The plunger locking and releasing mechanism has an actuator plate secured to the shaft of a ratchet pawl body for co-rotation therewith above the outside surface of a housing shaft in which a pin-accommodating hole is formed. The actuator plate has a pin-insertion hole smaller in diameter than the pin-accommodating hole and is manually movable about the axis of the shaft in opposite directions between a locking position in which the pin-insertion hole is in substantial alignment with the pin-accommodating hole and the engagement between a ratchet pawl and ratchet teeth on the plunger is maintained, and a releasing position in which the pin-insertion hole is out of alignment with the pin-accommodating hole, and the ratchet pawl is released from interlocking engagement with the ratchet teeth against the force of a ratchet pawl spring.

Abstract: In a ratchet-type hydraulic tensioner for a chain transmission, having a plunger and a housing forming a high pressure oil chamber, an excess supply oil discharge passage is provided. The discharge passage communicates with an oil supply passage leading from an oil supply opening, which receives oil under pressure from a oil pump, to a hydraulic check valve mechanism in the housing, which delivers oil to the high pressure oil chamber. Excess oil is discharged to the exterior of the tensioner housing and directed toward the chain. Excessive chain tension is avoided, and smooth and reliable chain travel, and suppression of whistling sounds, are achieved.

Abstract: A plastic movable guide for a belt or chain transmission has a plunger-engaging portion for contact with the plunger of a tensioner at a location remote from its pivot axis. A reinforcing plate is located in a slot in a resin guide body, and is slightly recessed at the location of the plunger-engaging portion so that it does not protrude from the slot opening and is not contacted by the plunger of the tensioner. Superior quietness of operation, ease of assembly, and reduction of production cost are achieved.

Abstract: A plastic movable guide for a chain or other traveling transmission medium, comprises a guide body composed of a shoe and a slotted plate-receiving portion integrally molded as a unit from a resin, and a reinforcing plate inserted into the slot. A mounting hole adjacent one end of the guide body is aligned with a hole adjacent one end of the reinforcing plate. The diameter of the hole in the reinforcing plate is larger than the diameter of the mounting hole in the guide body, so that the inner periphery of the hole in the reinforcing plate does not extend inward past the edge of the mounting hole. The guide so configured exhibits excellent quietness and assembly efficiency and can be produced at a relatively low cost.

Abstract: A ratchet tensioner includes a plunger releasing mechanism for turning a ratchet pawl against the force of a plunger spring to disengage a locking prong of the ratchet pawl from a rack tooth of a plunger. The plunger releasing mechanism has a pin insertion hole formed in a plunger housing transversely across a recessed groove formed in the housing for mounting the ratchet pawl, and a sloped surface formed on the ratchet pawl and normally extending obliquely across the axis of the pin insertion hole. The sloped surface, upon abutment with the tip end of a pin which is inserted in the pin insertion hole, is capable of causing the ratchet pawl to turn against the force of the ratchet spring to thereby disengage the locking prong of the ratchet pawl from the rack tooth of the plunger for releasing the plunger.

Abstract: The present invention relates to a hydraulic type tensioner with a relief valve. In this tensioner, a relief valve, which is opened and closed in accordance with the oil pressure of oil supplied under pressure from an oil pressure generating source such as an oil pump or the like through an oil supply port, is provided in a bypass oil path, which detours a check valve mechanism formed in a tensioner body and communicates between the oil supply port and a high pressure oil chamber.