Abstract: A tensioning device (32) for tensioning at least two, substantially length-invariant belts (18, 24) includes a first belt (18) guided about a first axis (A), which repeatedly guides an adjusting movement in an adjustment direction substantially orthogonal to the axial direction of the first axis (A). In addition, the first belt (18) and a second belt (24) are guided about a common second axis (B), whereby the tensioning directions (V18, V24) of the first belt (18) and of the second belt (24) in a region of the second axis (B) forms a varying angle of between 0° and 180°.

Abstract: In a ratchet-type hydraulic tensioner for use with a timing chain of an internal combustion engine, two or more oil reservoirs gradually receive oil fed under pressure from an external source, and supply the oil through a hydraulic valve mechanism to a high pressure oil chamber formed by a plunger and a housing in which the plunger is slidable. Throttle holes, formed in partition walls separating the reservoirs, control the flow of oil from one reservoir to another. An excess oil discharge hole is optionally provided in one of the reservoirs. The invention prevents abnormal protrusion of the plunger, reduces chain noise and component damage due to wear, and rapidly re-establishes proper tension on engine start-up.

Abstract: A motorcycle includes a frame, and an engine and transmission mounted to the frame. A swingarm is pivotably mounted to the frame, and a rear wheel is rotatably mounted to the swingarm. An output shaft of the transmission is coupled to the rear wheel to cause rotation of the rear wheel under power of the engine. A stationary tensioner is mounted to the frame such that as the rear wheel bounces up and down with respect to the frame, the tensioner maintains substantially constant tension and belt path length in the belt without requiring the tensioner to move in a translational or pivotal sense.

Abstract: A belt tension adjustment apparatus and an optical scanner using the same. The belt tension adjustment apparatus includes a plate spring and/or a tension spring. Utilizing the elasticity of the plate spring or the elastic forces provided by the plate spring and the tension spring, a section of the transmission belt bends to produce a tension in the belt. With the belt tension adjustment apparatus, belt tension in the transmission belt can be easily adjusted and hence the belt can be easily mounted or dismounted from the belt wheels during installation, maintenance or adjustment.

Abstract: A combination belt tensioner and idler has a fixed pivot structure. A moveable arm is mounted for pivotable movement about the pivot structure. A belt tensioning pulley is mounted on the moveable arm. A helical coil spring biases the moveable arm in a direction so as to force the pulley into tensioning engagement with a belt. A mounting bolt mounts the fixed pivot structure on a motor vehicle engine. An idler pulley is mounted for rotational movement about an axis defined by the mounting bolt.

Abstract: Engine accessory drive belt tension is maintained by a spring loaded roller positioned to impinge against the belt. Belt deflection is reflected by changes in position of the roller, and measured by a deflection sensor. Changes in deflection may indicate changes in belt elasticity, indicating the possible need to change the belt.

Abstract: An idler or tensioning assembly for an electronically controlled sanding/polishing machine is provided, the sanding/polishing machine utilizing a plurality of exchangeable polishing wheel assemblies of which the idler assembly is one. Each polishing wheel assembly interfaces with the sanding/polishing machine through a coolant manifold and a polishing wheel shaft receptor. The idler assembly is operative to provide releasable tension to a sanding/polishing belt that is situated around the idler and the associated sanding/polishing wheel. The idler assembly has a pivoting idler that is actuated by a hydraulic cylinder. The hydraulic cylinder utilizes coolant tapped from the coolant manifold of the idler assembly for actuation. Coolant is provided to the hydraulic cylinder in response to a valve signal. The idler assembly thus has a tensioned mode and an untensioned mode.

Abstract: To reduce seizing in a tensioner having a plunger slidable in a plunger-accommodating hole of a tensioner housing and biased in the projecting direction, the tensioner housing is formed of a hyper-eutectic Al—Si series alloy containing Si in the range from 14 to 16 weight % and having a particle diameter of proeutectic Si in the range from 20 to 30 &mgr;m.

Abstract: In a hydraulic tensioner, a check valve assembly comprises a synthetic resin ball guide with a check ball movable therein. Oil grooves are provided in the wall of the ball guide, and minimum clearance is allowed between the ball and the wall of the ball guide. The ball is biased toward a metal ball seat formed as a separate element from the ball guide and attached to the ball guide by crimping portions of the synthetic resin of the ball guide over a flange of the seat, using heat fusion. A metal retainer disc, also a separate element, is similarly attached to the ball guide by crimping using heat fusion. A resilient annular lip is formed on the synthetic resin ball guide, and the assembly is press-fit into a plunger-receiving hole in a tensioner housing with the lip in engagement with the wall of the hole.

Abstract: A belt tensioner (10) includes a housing part (12). The housing part (12) includes an elongated cylinder tube (18) in which a piston (14) is displaceably arranged. The belt tensioner (10) also includes a drive (16) which can exert a driving force onto the piston (14). The housing part (12) is constructed in a T-shape with a foot section (20) extending transversely away from the cylinder tube (18). The cylinder tube (18) is constructed in one piece with the cylinder tube and forms an accommodation space (30) for the drive (16). In a method for manufacturing such a belt tensioner (10), the foot section (20) forming the accommodation space (30) for the drive (16) is constructed in the housing part (12) by internal high pressure deformation.

Abstract: A drive assembly for a driven device having an input shaft is provided, including an attendant methodology for optimally configuring components thereof so as to minimize instability without recourse to utilization of a pivot regulating mechanism. The drive assembly includes a driving device having an output shaft, a driving device support structure, and a drive operatively linking the output shaft of the driving device with the input shaft of the driven device. The driving device support structure includes an anchorable base and a selectively positionable platform pivotable, with respect to the base, about a pivot axis so as to thereby define a tilt angle &agr; for the platform relative to a horizon. The drive including a drive sheave, a driven sheave, and an endless loop, a hub load being generated by the endless loop about the sheaves and acting therebetween along a hub load line. The hub load line has an angular relationship e relative to the horizon.

Abstract: A tensioner, for a timing chain, belt or the like in an internal combustion engine, has a projection-preventing hook that secures a spring-urged plunger in a withdrawn condition prior to installation of the tensioner, but releases the plunger during operation so that the plunger can exert a force on a pivoted chain- or belt-engaging tensioner lever. A resisting member is provided on a fulcrum pin on which the hook is pivoted, in order to exert a frictional force on the hook, thereby preventing the hook from unexpectedly returning to its plunger latching condition and preventing vibration noise to movements of the hook. The tensioner can be mounted without regard to its direction, and therefore a threaded mounting can be used, simplifying mounting and demounting of the tensioner.

Abstract: A belt tensioner for a power transmission belt is provided that utilizes asymmetric motion control and is operable in a first condition and a second condition. The belt tensioner has an arm with a belt engaging section and a drum section, a support member for securing the tensioner relative to the belt, and a spring that urges the arm to pivot about the support member in a first direction and urges the belt engaging section against the belt with a force to tension the belt. The tensioner also has a stator coupled to the support member to form arcuate spaces circumferentially spaced around the stator between the stator and the drum section and arcuate shaped wedges in the arcuate spaces. The tensioner further has a Belleville spring coupled to the arm for pivoting therewith and a friction device in sliding contact with the wedges and Belleville spring.

Abstract: An improved pneumatic tensioner apparatus is disclosed, the apparatus including: a main drive belt; a chuck assembly, suspended from said main drive belt, having a spinning member and a drive contact portion; a first frictional drive belt in a first track in contact with said drive contact portion operative to spin said chuck assembly; a first tension adjusting device operative to apply pressure to said first frictional drive belt tangentially to said drive contact portion; a second frictional drive belt disposed in at least one idler roller on an opposite side of said chuck assembly to said first frictional drive belt, said second frictional drive belt in contact with said drive contact portion; and a second tension adjusting device operative to apply pressure to said second frictional drive belt tangentially to said drive contact portion.

Abstract: An pneumatic tensioner apparatus is disclosed, the apparatus including: a main drive belt; a chuck assembly, suspended from the main drive belt, having a spinning member and a drive contact portion; a first frictional drive belt in a first track, the first frictional drive belt in contact with the drive contact portion operative to spin the chuck assembly; and a first tension adjusting device having at least one pneumatic tension adjustment member operative to apply pressure to the first frictional drive belt tangentially to the drive contact portion.

Abstract: A hydraulic chain or belt tensioner includes a ratchet-pawl interface on the piston skirt that can be reset to a locked position by rotating the piston and compressing it until locked. The tensioner preferably includes at least one flat on the piston. The flat prevents the piston from rotating axially and locks the piston into place. The locked position is especially useful for shipping the tensioner.

Abstract: A hydraulic tensioner that decreases the number of components, secures an adequate backlash, and prevents backward movement of a plunger. The hydraulic tensioner includes a hollow plunger having rack teeth formed on a portion of an outer circumferential surface, slidably received in a bore of the housing, where the plunger has an inner space to form a fluid chamber with the bore. A slider housing portion, having an inclined surface, located in the housing, receives a wedge-shaped slider having a ratchet portion adapted to engage with the rack teeth of the plunger and a second side surface. The wedge-shaped slider being slidable along the inclined surface of the slider housing portion in a direction crossing an axial centerline of the plunger. The hydraulic tensioner further includes a first spring biasing the plunger in a protruding direction, and a second spring biasing the slider such that the slider moves along the inclined slide surface of the slider housing portion.

Abstract: A chain tensioner has a spring-biased plunger with rack teeth engageable with teeth of wedge-shaped cam chips cooperating with a spring-biased cam-receiving ring in a recess formed in a tensioner housing. A seal plate, having a central hole through which the plunger extends, is provided as a closure for the recess to hold the cam chip assembly in place. A wire loop, for temporarily engaging a pin protruding laterally from the plunger, is pivoted in tube formed by rolling a portion of a seal plate. The wire loop holds the plunger in its retracted state while the tensioner is being installed, and automatically disengages the laterally protruding pin when the plunger is pushed inward by a tensioner lever, thereby releasing the plunger for normal operation.

Abstract: An idler or tensioning assembly for an electronically controlled sanding/polishing machine is provided, the sanding/polishing machine utilizing a plurality of exchangeable polishing wheel assemblies of which the idler assembly is one. Each polishing wheel assembly interfaces with the sanding/polishing machine through a coolant manifold and a polishing wheel shaft receptor. The idler assembly is operative to provide releasable tension to a sanding/polishing belt that is situated around the idler and the associated sanding/polishing wheel. The idler assembly has a pivoting idler that is actuated by a hydraulic cylinder. The hydraulic cylinder utilizes coolant tapped from the coolant manifold of the idler assembly for actuation. Coolant is provided to the hydraulic cylinder in response to a valve signal. The idler assembly thus has a tensioned mode and an untensioned mode.

Abstract: A chain drive assembly for an internal combustion engine comprises a chain tensioner (6) that acts upon a chain (2) that is used to drive the cam shafts (4) of the engine. The tensioner has a hydraulically actuated plunger (30) which is moveable within a housing and biasing means in the form of a solenoid (34), compression spring or motor that urges the plunger outwards of the housing at least when there is no hydraulic pressure. The tensioner is controlled by means of a control unit (8) that receives signals from various transducers that transmit signals providing information in relation to the performance of the engine. The control unit receives the measured information, calculates the desired tension to be applied to the chain and transmits the control signal to the chain tensioner so as to operate the biasing means or control the hydraulic pressure so that the desired chain tension is applied.

Abstract: In a ratchet type tensioner comprising a housing, a plunger slidable in, and protruding from, the housing, and biased in a protruding direction, a ratchet mechanism comprising a rack formed on a side surface of the plunger, and a pawl provided on the housing and engageable with the rack to prevent the return movement of the plunger, the pawl is composed of a sintered alloy having a density of at least 7.2 g/cm3. The sintered alloy is formed by warm molding, high temperature sintering, recompression, or combinations thereof, and preferably contains a total of 0.5 to 8 weight % of at least one element from the group consisting of Nickel, Copper and Molybdenum. The balance of the composition of the sintered alloy consists of Iron and impurities. The invention provides a ratchet type tensioner having a high strength and excellent wear resistance at a low cost.

Abstract: A tensioning device for a drive system having a flexible drive element mounted on at least one driven member, the tensioning device including a first tensioning member having a first side, a second side, and a first contact surface for contacting the drive element and a second tensioning member having a first side, a second side, and a second contact surface for contacting the drive element. The tensioning members are secured to the first and second ends of an elongated connecting member, positioning the members in a spaced relationship to one another so that the contact surfaces of the tensioning members are in opposing disposition facing one another. The tensioning members are spaced apart so as to permit the first and second runs of the drive element to pass between the tensioning member contact surfaces.

Abstract: The invention is an improved tensioner for tensioning a power transmission belt. It is of the type having a pulley adapted to communicate with a surface of a power transmission belt, an arm supporting the pulley upon which the pulley is rotatably mounted via a pulley bearing, and having a shaft supporting the arm. The shaft is rotatably supported by a pivot bearing. Further, it is of the type having an attachment point for a strut with the strut attached to the attachment point. It is improved by the pulley and the attachment point being laterally offset in relation to the pivot bearing and substantially balanced in terms of parasitic torque across the pivot bearing.

Abstract: A belt driving apparatus has a motor for generating the driving force, a toothed driving pulley rotating by the driving force, an endless toothed belt wound on the pulley, wherein a first surface of the toothed belt has teeth corresponding to teeth of the pulley and a second surface of the toothed belt is substantially smooth, an auxiliary roller for holding the toothed belt in a gap defined by the pulley and the auxiliary roller, a roller holding unit for holding the pulley and the auxiliary roller to be able to respectively rotate on axes of the pulley and the auxiliary roller and maintaining the gap between the pulley and the auxiliary roller and an urging member for urging the roller holding unit in a direction to the toothed belt around the pulley in order for the auxiliary roller hold by the roller holding unit to provide a tension to the toothed belt.

Abstract: A shiftable toothed-belt drive, containing an engagement and disengagement device, in order alternately to mesh radially and demesh radially a toothed belt, which is guided around at least two gearwheels, with and from at least one of the two gearwheels. A disengager in the form of two externally profiled pulleys is urged axially along the shaft of one of the gearwheels supporting the toothed belt for radially raising the belt and demeshing the belt from the gearwheel. An engager engages the outside of the belt for tensioning the belt sufficiently to counter the effect of the disengager, move the pulleys apart and mesh the belt with the one gearwheel.

Abstract: A piston rod position detecting mechanism is proposed which can detect continuously or in a multiple-point manner that the piston rod position has changed due to increase or decrease in the protruding amount of the piston rod due to aging. The protruding amount from a cylinder end wall is detected by a position detecting mechanism comprising a detecting coil housed in a bobbin provided at the cylinder end, a flange portion formed on the piston rod, and a coil spring. Also, an autotensioner and an electromagnetic valve with such a position detector are proposed. Further, a belt tension adjusting device is provided with a detector for detecting the position of a tension pulley which is pivotable with increase or decrease in the belt tension.

Abstract: The belt tension/drive for a pinch roller system of the present invention combines means for urging a plurality of pinch rollers toward a capstan roller with means for driving pinch rollers when a pinch roller is not in contact with the capstan roller. The capstan roller is surrounded by and aligned with a plurality of pinch rollers. A resilient belt disposed about the plurality of pinch rollers urges the pinch rollers toward the capstan roller and drives any pinch roller not in contact with the capstan roller, assuring that all pinch rollers maintain the same surface speed as the capstan roller.

Abstract: The present invention relates to a tensioner for endless driving elements, such as chains, belts etc., comprising a tensioning piston provided with locking means, and a locking piston which is implemented such that it is adapted to be engaged with and disengaged from said locking means so as to arrest or release the movement of said tensioning piston, said locking piston comprising an operating section causing said locking piston to move to the arresting position and to the release position, and a locking area used for engagement with said locking means of the tensioning piston and arranged separately from said operating section.

Abstract: A drive unit of a carriage has a drive wheel and a deflector, offset parallel to a racks both of which are implemented as gearwheels, around which a closed elastic toothed belt with teeth on both sides is guided, whose inner teeth engage with the wheels described and whose outer teeth engage with the rack. A pressure block relocatable relative to the rack is positioned between the wheels, which exercises an elastic force on the part of the toothed belt facing the rack by means of a pressure surface under the influence of the part facing away from the rack, which presses the first part mentioned against the rack. In this way, a snug engagement with the rack and low-noise and uniform movement of the carriage are always ensured. A pressure wheel implemented as a pinion and engaging with the inner teeth of the toothed belt can also be used instead of the pressure block.

Abstract: Clutch arrangement which includes a movable actuating device and a pivotally mounted idler device. The idler device includes a guide wheel and an idler wheel. The idler wheel is arranged to engage a mechanism which transfers drive between at least two drive mechanisms. The guide wheel is arranged to engage or abut the actuating device. The idler device experiences pivotal motion when the actuating device is moved into engagement with the guide wheel.

Abstract: A tensioner, in which a bearing of the drive shaft is not necessary and the initial load of the torsion spring is maintained when the tensioner is disassembled, two shaft members that compose a set and that are engaged by screw portions, and a spring that is inserted in the driving unit by fastening onto the shaft members the hooking portions that are located at each end of the spring. The spring is inserted in the set of the shaft members under an appropriate windup condition. One shaft member moves forward from the loaded strength by the spring. The tensioner also includes, beside the driving unit, a case into which the driving unit is inserted, and a system that prevents the driving unit from coming off the case.

Abstract: A power transmission device is disclosed which is capable of easily, swiftly and appropriately altering the distance between the axes of a pair of transmission wheels such as pulleys, enabling an endless belt to be kept under constant and appropriate tension without necessitating a tension roller. This power transmission device comprises an endless belt wound around a pair of transmission wheels; and a cam-type adjusting mechanism which is interposed between a driving side supporting member and a driven side supporting member and configured to adjust a distance between the axes of the wheels. This cam-type adjusting mechanism comprises a supporting shaft secured to either the driving side supporting member or the driven side supporting member and disposed parallel to the rotational axes of the wheels; and a cam rotatably secured via a manipulating boss member to the supporting shaft.

Abstract: A blade tensioner is configured with a blade shoe having a chain sliding face, several plate-spring-like blade springs stacked on the reverse side of chain sliding face of the blade shoe in order to apply a spring force to the blade shoe, and spacer members provided between respective adjoining blade springs and brought in contact with corresponding blade springs at least at two points separated from each other by a fixed distance. In such case, the blade springs contact the spacer members at a fixed span. Accordingly, the damping factor of the overall blade spring or system is constant, so that the damping performance of the blade tensioner can be stabilized.

Abstract: An element correction method of continuously variable transmission belt assembled through supporting an element laminated body constituted of a number of metal elements on a belt laminated body constituted of a plurality of steel belts. The method comprises: a pre-step of removing the belt laminated body from the continuously variable transmission belt, and attaching a dummy belt in place of the removed belt laminated body; a trial step of applying a load on a continuously variable transmission belt to which the dummy belt is attached for trial use; and a post-step of removing the dummy belt from the continuously variable transmission belt after completion of the trial step, and attaching the belt laminated body removed in the pre-step or an equivalent belt laminated body in place of the removed dummy belt. Thus, abnormal shaped portions of the metal element can be efficiently and assuredly removed.

Abstract: A piston rod position detecting mechanism is proposed which can detect continuously or in a multiple-point manner that the piston rod position has changed due to increase or decrease in the protruding amount of the piston rod due to aging. The protruding amount from a cylinder end wall is detected by a position detecting mechanism comprising a detecting coil housed in a bobbin provided at the cylinder end, a flange portion formed on the piston rod, and a coil spring. Also, an autotensioner and an electromagnetic valve with such a position detector are proposed. Further, a belt tension adjusting device is provided with a detector for detecting the position of a tension pulley which is pivotable with increase or decrease in the belt tension.

Abstract: A tensioner has a tensioner body and a plunger slidably mounted in a hollow cylindrical part of the tensioner body. A plug is screwed into a female or internal screw formed from one end of the hollow cylindrical part. A coil spring is loaded in a spring accommodating hole of the plunger and in a spring accommodating hole of the plug. The coil spring is a left hand spring. On the other hand, the direction of the plug being screwed into the tensioner body is right, which is opposite to the winding direction of the coil spring. Since the direction of the plug being screwed and the winding direction of the coil spring are different, when the plug is being screwed into the tensioner body with the coil spring held between the plug and the plunger, the coil spring slides on the bottom of the spring accommodating hole of the plunger or on the bottom of the spring accommodating hole of the plug without being caught at either end.

Abstract: A belt tension adjustment apparatus and an optical scanner using the same. The belt tension adjustment apparatus includes a plate spring and/or a tension spring. Utilizing the elasticity of the plate spring or the elastic forces provided by the plate spring and the tension spring, a section of the transmission belt bends to produce a tension in the belt. With the belt tension adjustment apparatus, belt tension in the transmission belt can be easily adjusted and hence the belt can be easily mounted or dismounted from the belt wheels during installation, maintenance or adjustment.

Abstract: A work bench includes a frame, a bench surface on the frame with the bench surface including at least two members, one of which is movable along the frame for clamping a workpiece between the members. A mechanism for moving the member includes two screws coupled with the members. The two screws are spaced with the member for moving the member upon rotation of the screws. A sprocket is coupled with each of the screws. A transmission belt or chain is coupled with the sprockets. At least one handle is coupled with one of the screws to rotate the screws. At least one clutch is coupled with the at least one screw to limit clamping pressure on the workpiece. The clutch enables rotation of one screw with respect to the other screw so that workpieces may be clamped between the members and clamping of the workpiece may be accomplished by rotation of the screws with one hand of the operator. Also, a guard may be present which covers the transmission belt or chain.

Abstract: An idle wheel adjustment assembly has a generally L-shaped frame, a coiled spring, an oblong rocking frame, a first shaft pin, a first bearing, a first idle wheel, a second shaft pin, a second bearing, and a second idle wheel. The generally L-shaped frame has a through hole and an end column. The oblong rocking frame has a main shaft, an upper pillar, an upper circular hole, and a lower round hole. The first bearing is inserted in the first idle wheel. The second bearing is inserted in the second idle wheel. The first shaft pin is inserted through the upper circular hole and the first bearing. The second shaft pin is inserted through the lower round hole and the second bearing. The main shaft is inserted through the through hole. The coiled spring has a first hook end connected to the upper pillar and a second hook end connected to the end column.

Abstract: In a belt tensioner of a seat belt in a vehicle, particularly a motor vehicle, for the return movement of the belt, a return spring is provided which is able to be tensioned by a motor as a function of parameters. The motor may also be used for a reversible tightening of the belt.

Abstract: A blade tensioner includes a blade shoe having a chain slide face, a plurality of blade springs for applying spring force to the blade shoe, and a spacer member interposed between the adjacent blade springs. Each of the blade springs is in the shape of a leaf spring. The blade springs are positioned and layered on the opposite side of the blade shoe from the chain slide face. The spacer member preferably contacts the corresponding blade spring at two contact points apart from each other at a uniform distance. In the blade tensioner of this invention, the blade spring contacts the spacer member at a constant span, which causes the damping coefficient of the whole blade spring to be constant and also causes the damping performance of the blade tensioner to be stable.

Abstract: A tensioning device includes an adjustable tensioning arm having first and second opposed ends, a first mounting bracket secured to the first end of the adjustable tensioning arm, and a second mounting bracket pivotally connected to the second end of the adjustable tensioning arm. The adjustable tensioning arm includes a middle member having first and second opposed ends, a first end member engaged with and extending from the first end of the middle member and a second end member engaged with and extending from the second end of the middle member.

Abstract: A combination starter-generator system for use in a vehicle is provided. The vehicle has an internal combustion engine and a battery. The system includes a starter-generator electrically coupled to the battery to generate a current and to start the internal combustion engine. A drive mechanism connects the starter-generator machine and the internal combustion engine. The starter-generator machine generates the current by receiving a charging torque from one side of the drive mechanism and starts the internal combustion engine by imparting a starting torque to a different side of the drive mechanism. The charging torque or the starting torque is a greater torque. A passive tensioning system cooperates with the drive mechanism to tension the drive mechanism only at the side of the greater torque.

Abstract: A chain tensioner, includes a housing intended for attachment to a stationary machine element of an internal combustion engine, and a piston received in the housing for axial displacement against a strand of a chain to thereby implement a tensioning of the chain. An adjusting mechanism is provided for moving the housing relative to the machine element in a direction to and away from the strand of the chain, whereby a spacer establishes a distance between the housing and the strand to thereby define an installation position of the housing.

Abstract: The belt tension/drive for a pinch roller system of the present invention combines means for urging a plurality of pinch rollers toward a capstan roller with means for driving pinch rollers when a pinch roller is not in contact with the capstan roller. The capstan roller is surrounded by and aligned with a plurality of pinch rollers. A resilient belt disposed about the plurality of pinch rollers urges the pinch rollers toward the capstan roller and drives any pinch roller not in contact with the capstan roller, assuring that all pinch rollers maintain the same surface speed as the capstan roller.

Abstract: In a ratchet-type hydraulic tensioner for use with a timing chain of an internal combustion engine, two or more oil reservoirs gradually receive oil fed under pressure from an external source, and supply the oil through a hydraulic valve mechanism to a high pressure oil chamber formed by a plunger and a housing in which the plunger is slidable. Throttle holes, formed in partition walls separating the reservoirs, control the flow of oil from one reservoir to another. An excess oil discharge hole is optionally provided in one of the reservoirs. The invention prevents abnormal protrusion of the plunger, reduces chain noise and component damage due to wear, and rapidly re-establishes proper tension on engine start-up.

Abstract: In a chain tensioner having a plunger biased to protrude from a housing by a spring, a pair of wedge-shaped cams are received in tapered recesses in the end of the housing, cooperate with racks formed on opposite sides of the plunger, and are urged against oblique seats formed by the tapered recesses by a biasing spring. The cams and racks produce a ratcheting action maintaining chain tension by preventing retracting movement of the plunger. The cams and racks disperse the load imparted to the plunger by the chain, and reduce localized wear, allowing the housing to be made from a light weight material such as aluminum. Accuracy requirements associated with conventional pawl-type ratcheting tensioners are avoided.

Abstract: A tensioner is formed with components having improved wear resistance. At least one component of the tensioner is covered with a diamond-like amorphous carbon coating (DLC). The coating is applied to the tensioner without causing hydrogen brittleness in metallic members. In addition, the coating may be formed on tensioner components formed with resin. In one embodiment of the invention, a metal element is dispersed into the diamond-like amorphous carbon coating.

Abstract: A chain tensioner apparatus includes a mounting bracket adapted for connection to an associated engine block. The mounting bracket defines a pivot point and a support surface. A blade is connected to the bracket and includes: (i) first and second opposite end portions joined together by a central portion; (ii) a hub defined by the first end portion; and, (iii) a first end wall connecting the hub to the central portion. The hub of the blade is pivotably connected to the bracket at the pivot point and the second end of the blade abuts the support surface. The blade defines an exterior chain guide surface adapted for slidingly abutting an associated chain of an associated chain drive system. The chain tensioner apparatus further includes a tensioning spring connected to the blade, the spring having opposite first and second ends located respectively adjacent the first and second opposite end portions of the blade. The spring contacts and exerts a biasing force on the central portion of the blade.

Abstract: A hydraulic timing chain tensioner assembly includes a shoe configured to contact a timing chain, and a plunger having a distal end abutting the shoe. The plunger is movable within a cylindrical opening formed in a tensioner body. The cylindrical opening includes oil and a spring member therein to cushion chain loads transmitted through the shoe and plunger. A spring-controlled oil pressure relief structure is operatively associated with the cylindrical opening to vent the oil when the oil is pressurized above a predetermined level by the plunger, thereby enabling further movement of the plunger into the cylindrical opening to reduce maximum loads experienced by the timing chain.