Abstract: A reversible locking device 1 for a tensioner 100 of a timing chain 20 includes a locking device body 3, integral with the tensioner 100 and protruding with respect to the body of the tensioner 100, which has a shaped slot 2. A perforated protrusion 4 is integral with the shoe 5 carried by the piston 6 and protrudes with respect to the shoe 5 so that its hole is aligned with the shaped slot. A rod 7 has a first part 8 with a shape complementary to that of the shaped slot 2 and a second part 9 bearing at one end a conical portion 10 adapted to couple it irreversibly to the perforated protrusion 4 integral with the shoe 5.

Abstract: A tensioner for imparting tension to a chain having a body, a resilient chain guide element, at least one blade spring, and at least one bracket. The body of the tensioner has a surface with a profile of the path of a new chain and a groove found longitudinally along the length of the surface. The resilient chain guide element, on the surface of the body has a chain contact surface and two ends wrapped around the ends of the body, with the chain guide being sufficiently larger than the body, such that the chain contact surface is capable of being biased away from the body. The blade spring is present in the groove with its end in the containments means of the groove, biasing the chain guide out and away from the body.

Abstract: An eccentric pivot arm tensioner capable of automatic belt tensioning and substantially simultaneous operating range indexing during installation. The tensioner comprises a stop plate and cooperating lock plate. The tensioner comprises a pivot arm having a pivot arm member that cooperatively engages a base plate member. In a first, or transit mode, the pivot arm member temporarily engages the base plate member to put a torsion spring and thereby the pivot arm in a preloaded condition. The lock plate is engaged with the stop plate. As a mounting fastener is engaged into a mounting surface the pivot arm member is automatically disengaged from the base plate member by an axial movement of the pivot arm, thereby allowing the pivot arm to rotate and thereby impart a torsion spring force to a belt, i.e., tensioning the belt in an operating position.

Abstract: A chain tensioning device links multiple tensioning arms to a common link, causing the tensioning arms to rotate into and displace chain strands with a single applied force and motion. The two tensioning arms rotate and tension proportionally, and when the pivot pin distances are equal, the two tensioning arms rotate and tension equally. The chain tensioner is preferably used to tension two slack chains flanking an auxiliary drive shaft. The chain tensioner is biased against the chain by a hydraulic tensioning assembly in one embodiment and by a spring tensioning assembly in another embodiment.

Abstract: In a hydraulic tensioner having a relief valve inside its plunger, a relief valve spring-receiving plug, press-fit into the plunger is formed by forging a plurality of flat surfaces on its exterior. These flat surfaces, in cooperation with the cylindrical inner wall of the plunger, form plural oil passages, each having a segment-shaped cross-section. The oil passages allow flow of oil past the plug to a discharge opening at the front end of the plunger, and the flow of oil is substantially unaffected by circumferential displacement of the oil passages on the periphery of the plug relative to the oil passages on the periphery of the relief valve seat.

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 tensioner for imparting tension to a chain having a body, a resilient chain guide element a support member and at least one blade spring. The body contains at least one groove on its surface adjacent to the resilient chain guide for containing a blade spring in compression. The length of the blade spring is less than the length of the support member.

Abstract: A pivot joint for a single blade spring tensioner or double blade spring tensioner generates a biased friction loss at a pivot joint. The friction torque generated in one direction of joint rotation is greater than the friction torque generated in the opposite direction of rotation. In one embodiment, the direction of torque bias at the joints is used to make the damping of the blade spring greater in compression than in extension. High damping in compression and low damping in extension is a desirable characteristic for a tensioner in most applications. The device may be designed to act as a one-way clutch or as a two-way clutch. The device may also be designed to apply large friction torques only when the joint undergoes large amplitude motions (loss of control).

Abstract: A chain drive system includes a drive sprocket, a driven sprocket and a chain looped over the drive sprocket and the driven sprocket. The chain and the sprocket having respective sliding surfaces slidable relative to each other in the presence of lubricating oil, and any adjacent chain components of the chain having respective sliding surfaces slidable relative to each other in the presence of lubricating oil. At least one of the sliding surfaces between the chain and the sprocket and at least one of the sliding surfaces between any adjacent chain components have hard carbon coatings formed on base portions thereof. Each of the hard carbon coatings has a hydrogen content of 10 atomic % or less.

Abstract: A stepped set groove having shallow and deep portions is formed in the inner periphery of a cylinder chamber formed in a housing of a chain tensioner near its open end. A radially and elastically deformable set ring having circumferentially separated ends is received in the set groove in a radially compressed state. The set ring has at the respective ends thereof a pair of grip portions which are received in a cutout formed in housing at its front end. By engaging the set ring in an engaging groove formed in the outer periphery of the plunger near its front end and the shallow portion, it is possible to keep the plunger pushed into the cylinder chamber. In this state, the chain tensioner is mounted in position.

Abstract: In an engine timing chain drive, a pivoted chain guide is provided on the tension side of the chain, and a synchronizing sprocket is incorporated into the chain guide and driven by the chain. The synchronizing sprocket rotates a cam which effects reciprocating movement of the guide to compensate for cyclic variations in tension resulting from operation of intake and exhaust valves.

Abstract: A tensioner for maintaining tension in a timing chain or belt comprises a pivotally mounted lever body biased in a direction to increase tension in the chain or belt, and having a built-in, one-way clutch permitting the lever to pivot the tension-increasing direction but blocking pivoting movement in the opposite direction.

Abstract: A tensioner for imparting tension to a chain in a closed loop chain drive system of an internal combustion engine is disclosed. The tensioner contains two tensioning devices, one for each strand of chain that traverses between a drive sprocket and at least one driven sprocket. The two tensioning devices are installed on a single bracket which is mounted to the engine housing at a single dampened pivot mount. The pivot mount is positioned equidistant from the mid points along the lengths of each of the chain sliding surfaces of each of the tensioning devices to substantially form an isosceles triangle.

Abstract: The present invention relates to a belt tension adjustment mechanism for use with a device including a main body and a belt pulley set. The belt pulley set includes a belt. The belt tension adjustment mechanism includes a slab, at least two tension pulleys and a fixing element. A tight tension force and a slack tension force are exerted on the opposite sides of the belt to define a tight side and a slack side of the belt when the belt pulley set runs. A counterforce is generated from the tight side of the belt to exert on the tension pulley contacting with the tight side, the slab is moved in response to the counterforce. The slack side of the belt is suppressed by the tension pulley contacting with the slack side such that the slack tension force is adjustable.

Abstract: A chain tensioner includes a housing having a cylinder chamber. A plunger is slidably mounted in the cylinder chamber. A spring is mounted in the cylinder chamber to bias the plunger outwardly of the cylinder chamber. The plunger has a radially extending locking pin at its lower portion near its front end. The housing is formed with a pin hole extending substantially perpendicular to an axis of the cylinder chamber near the front end of the housing and under the cylinder chamber. The chain tensioner further includes a support pin inserted in the pin hole, and a locking lever supported on the support pin so as to be pivotable about the support pin. The locking lever can engage the locking pin when the plunger is sufficiently pushed into the cylinder chamber, thereby keeping the plunger pushed in the cylinder chamber.

Abstract: 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°. 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.

Abstract: A hand-held power tool for driving a working tool (1) includes a drive belt (3), first and second arms (5a, 5b) longitudinally displaceable relative to each other and carrying respective deflection rollers (6) of the drive belt (3), a belt tensioning device (4) located between the first and second arms (5a, 5b) and including a spring (8) preloaded against the first arm (5a), and a displaceable pressure piston (9) located between the spring (8) and the second arm (56).

Abstract: A ratchet assembly includes a threaded rod and a support collar that defines a bore. A portion of the threaded rod is disposed in the axial bore of the support collar. A ratchet pawl is pivotable carried by the support collar between locked and unlocked positions. The ratchet pawl has at least one tooth that threadably engages the threaded rod when the ratchet pawl is in the locked position to allow the threaded rod to threadably rotate with respect to the support collar for fine position adjustments. The ratchet pawl automatically pivots to the unlocked position when the threaded rod is forced in a direction from the first end toward the second end to allow for gross position adjustments.

Abstract: A tensioner (10) features a backstop device (40) which allows free rotation of the pivot arm (20) in one direction but not the other. Reverse rotation is prevented by friction that is able to resist torque on the pivot arm (20) under ordinary operating conditions which otherwise could permit belt tooth-skip to occur. In disclosed embodiments, the backstop device (40) includes a stop sleeve (50) and a clamp holder (60) which are axially interlocked and are able to rotate relative to each other. A clutch spring (80) surrounds permits relative rotation between the stop sleeve (50) and the clamp holder (60) in one direction but not the other. A clamp (70) retained within the clamp holder (60) frictionally engages the pivot shaft. A viscous coupling may be used in place of the frictional clamp.

Abstract: An accessory drive for an engine has a belt driven starter generator adapted for driving and being driven by the engine. In an exemplary embodiment, the drive includes a first engine drive pulley and a second starter drive pulley. A drive belt engages the drive pulleys for driving either pulley from the other. A dual belt tensioner made as a preassembled unit has a carrier with a central pivot mounted to the engine and first and second carrier arms extending radially from the central pivot. A first tensioner mounted on the first arm carries a first tensioner pulley biased against a first belt run adjacent the second drive pulley that is slack during engine starting.

Abstract: A tensioner for imparting tension to a chain having a body, a resilient chain guide element, at least one blade spring, and at least one bracket. The body of the tensioner has a surface with a profile of the path of a new chain and a groove found longitudinally along the length of the surface. The resilient chain guide element, on the surface of the body has a chain contact surface and two ends wrapped around the ends of the body, with the chain guide being sufficiently larger than the body, such that the chain contact surface is capable of being biased away from the body. The blade spring is present in the groove with its end in the containments means of the groove, biasing the chain guide out and away from the body. At least one bracket is fixedly attached to the body and has a pivot.

Abstract: An all terrain vehicle includes a caliper bracket that moves with the movement of a rear axle by the rotation of an eccentric hub. The eccentric hub rotatably supports the rear axle in a position eccentric to the radial center of an axle supporting section. The caliper bracket includes a range specifying section or, specifically, a first engaging portion, which engages with the rear arm, for specifying the rotating range of the eccentric hub according to the position of engagement with the rear arm. The rear arm includes a second engaging portion that engages with the first engaging portion.

Abstract: A blade tensioner comprising a blade shoe with a proximal end pivotally attached to the bracket and a distal end of a clevis shape having a raised portion and a recessed portion for receiving a semicircular ratchet wheel, with an edge of the raised portion defined by a radial journal in between a pair of shoulders. The ratchet wheel is pivotally attached to the recessed portion of the distal end of the blade shoe having a plurality of ratchet teeth, a pair of shoulders, and a reduced diameter portion forming a bearing surface with the radial journal of the raised portion of the distal end. A ramp surface having a plurality of ramp teeth that receives the ratchet teeth of the ratchet wheel and allows freedom of movement in the direction of the pivot pin, but limits movement in the opposite direction to the designated backlash.

Abstract: A tensioner that includes a piston supported slidably in a piston bore formed in a housing, a piston spring biasing the piston in the protruding direction, and a circlip member having an expandable ring-shaped body that is engageable with the rack teeth of the piston. In the piston bore, the ring-shaped body of the circlip member is adapted to engage with an upper and lower stop surface. The rack teeth of the piston are formed in such a shape that when the ring-shaped body of the circlip member engages with the upper stop surface of the piston bore, the piston is permitted to move in the protruding direction and, when the ring-shaped body of the circlip member engages with the lower stop surface of the piston bore, the piston restricts movement in the retracting direction.

Abstract: The invention relates to a guide unit (1a) associated with a traction drive means, which guide unit (1a) comprises a tensioning element (3a) and a guide element (4a). The components: the tensioning element (3a) and guide element (4a), which are displaceable separately from one another with respect to a housing (2), are associated with separate regions of the traction means (8) in the operating state of the traction means drive.

Abstract: There is provided a pretension loading method for a power transmission chain, in which a chain with an endless loop shape having a plurality of laminated link plates bendably connected to each other by pin members is wound around a plurality of rollers and the chain is endlessly rotated while a load is loaded on the chain so as to load pretension on the chain, the method including the steps of: (a) maintaining the chain in a substantial tension state without a slack by controlling tension of at least one of the plurality of rollers while endlessly rotating the chain; (b) measuring a length of the chain in the tension state; (c) stretching the chain to a target length by controlling a displacement of the at least one of the rollers; (d) maintaining the chain in a substantial tension state without a slack by controlling tension of the at least one of the rollers; and (e) measuring the length of the chain in the tension state.

Abstract: In a hydraulic tensioner a cylindrical plunger slidably protrudes from a plunger-accommodating hole in a tensioner housing. A check valve unit allows oil to flow under pressure into a high pressure chamber formed by the plunger and the housing, but blocks reverse flow. The plunger is biased in the protruding direction by a spring located in the high pressure chamber. The plunger has an annular groove in its outer circumferential surface, and a C-shaped ring disposed in the groove is resiliently biased radially outwardly against the inner circumferential wall of the plunger-accommodating hole. A radial clearances is provided between the ring and the bottom of the groove, and the ring also fits into the groove with an axial clearance.

Abstract: Tensioning roller device including a non-rotating part about which there is rotationally mounted a pulley-forming rotating assembly designed to collaborate with a belt or a chain and a rolling bearing positioned between the non-rotating part and the pulley and including a rotating ring, a non-rotating ring and rolling elements, the pulley including a rigid rim including a first part fixed to the rotating ring of the bearing and a second part that can move with respect to the first part under the action of an elastic element, and an expandable sleeve of annular overall shape designed to be in contact with the belt or the chain, the diameter of the expandable sleeve varying according to how hard it is pressed by the second part.

Abstract: A belt assembly, particularly for driving camshafts of an internal combustion engine, includes a driving gear, at least one driven gear, a belt, and a first and a second tensioner blade that are joined to one another for transmitting a defined force and motion. One tensioner blade can be subjected to the action of tension force by use of a first tensioning device supported on the tensioner blade on one side and externally on the other, and the tensioner blades can be subjected to the action of tension force by use of a second tensioning device both with regard to one another as well as with regard to a case of the internal combustion engine.

Abstract: An auto-tensioner includes a housing having an open end and a closed bottom at another end. A cylindrical plunger is slidably inserted in the housing with its open end facing the closed bottom of the housing and its other end protruding from the housing. A ring-shaped seal member is mounted between the inner periphery of the housing and the outer periphery of the plunger for hermetically sealing oil in the housing. A screw rod and a nut member are mounted in the plunger so as to be coaxial with the plunger, with the nut member in threaded engagement with the screw rod. A return spring is mounted between the nut member and the plunger to bias the nut member and the plunger in a direction axially away from each other. A spring is mounted between the screw rod and the closed bottom of the housing to bias the screw rod in a direction away from the closed bottom of the housing.

Abstract: Traction element tensioner (1), which is preferably a hydraulic traction element tensioner for a chain drive, with a housing (2), which holds a tensioning piston (3) that can move axially and that is adjacent to a tensioner high-pressure space (4). The tensioner high-pressure space (4) is fed via a fluid supply opening (5) and also a non-return valve (6). The traction element tensioner (1) includes a valve assembly, which is constructed as a pressure-limiting valve (7) and limits a fluid pressure in the tensioner high-pressure space (4).

Abstract: A camshaft drive system for an internal combustion engine includes a drive sprocket fixed upon a crankshaft of the engine and a driven sprocket fixed upon a camshaft of the engine. A flexible power transmission element extends between the drive sprocket and driven sprocket. A tensioning device for the flexible power transmission element includes a linear actuator and a number of movable contactors for engaging and tensioning both the slack side and the tight side of the power transmission element, such that proper phasing of the camshaft with respect to the crankshaft is maintained.

Abstract: A chain or belt tensioner comprises a plunger displaceable in a bore of a housing between retracted and extended positions. The plunger and the bore between them define a variable volume chamber for receipt of pressurised hydraulic fluid. The tensioner is designed for insertion into a supporting bore of the cylinder head of an internal combustion engine such that the plunger has only a limited number of possible orientations so that it can engage with the tensioner arm. The plunger has an air purge passage that extends from adjacent to the chamber to atmosphere. The passage formation is designed so that there is a portion of it adjacent to the chamber is uppermost in any orientation of the plunger so as to ensure rapid and effective air purging. There may be a single air purge passage extending in an axial direction along the length of the plunger or a combination of several axial and circumferential portions that permit the plunger to be disposed in more than one orientation.

Abstract: The apparatus of the present invention provides an improved automotive accessory drive system. The automotive accessory drive system including a drive pulley operatively connected to an engine, and a plurality of driven pulleys operatively connected to one of a plurality of driven devices. A flexible drive belt connectively couples the drive pulley and the plurality of driven pulleys, and is operable to transfer drive forces therebetween. The automotive accessory drive system also includes a flexible drive belt tensioner operable to maintain frictional engagement between the flexible drive belt and the drive pulley and at least one of the driven pulleys. The flexible drive belt tensioner has a damper element that preferably includes a damper housing, and a variable viscosity fluid disposed within the damper housing. The variable viscosity fluid is configured to provide a variable dampening rate and is selectively operable to lock the flexible drive belt tensioner.

Abstract: The boss portion of an arm is oscillatably supported with respect to a support member. A tension pulley is rotatably engaged with a tip portion of the arm. A guide plate is fixed to the axial tip portion of the support member to face the boss portion. A friction plate is sandwiched between the boss portion and the guide plate to apply an oscillational resistance to the boss portion by a spring. A vibration attenuating member is provided in the guide plate so as to control the vibration of the guide plate caused by a stick-slip phenomenon in contacting portions between the friction plate, boss portion and guide plate.

Abstract: A pulley fixing apparatus of an office machine having a pulley fixing part rotatably fixing a driven pulley on a frame, a sliding part movably supporting the pulley fixing part on the frame, and an automatic tension adjusting part elastically urging the pulley fixing part in a direction such that the driven pulley imparts a predetermined tension to a power-transmitting belt. The pulley fixing apparatus readily enables mounting and dismounting of the power-transmitting belt and the driven pulley and control of the power-transmitting belt tension by simplifying structure and assembly. Further, the pulley fixing apparatus reduces manufacturing cost and assembly time by decreasing the number of parts.

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: In an auto tensioner, a high pressure oil chamber sectioned by a leading end portion of a cylinder and a plunger is provided within the cylinder. A gas chamber and an oil reservoir chamber are sectioned in a sealed manner in an outer periphery of the cylinder and the plunger. A first oil passage communicating the gas chamber with the high pressure oil chamber is provided within the plunger. A second oil passage communicating the high pressure oil chamber with the oil reservoir chamber is provided in the cylinder. The first oil passage is provided with a pressure side damping force generating means, (an orifice hole) and a first check valve closing during expansion. A second check valve closing during compression is provided in the second oil passage, and a locking means (an electromagnetic valve) closing the first check valve is provided.

Abstract: In a ratchet type chain tensioner, having a toothed rack on its plunger and a pawl cooperable with the rack, a recess is provided between the front end of the rack and the protruding end of the plunger. In the initial stages of operation of the tensioner, the pawl can enter the recess while permitting the plunger to protrude and retract freely within a limited range. Therafter, when the chain controlled by the tensioner becomes elongated, the pawl cooperates with the rack to limit retraction of the plunger.

Abstract: In a hydraulic chain tensioner for an engine timing drive, an annular groove is formed on an outer circumferential surface of a plunger, and a friction ring is disposed in the groove. The friction ring is composed of an external resin ring and an internal steel ring incorporated into the inside of the resin ring. The friction ring is fitted into the annular groove of the plunger with a predetermined axial clearance. It allows the tensioner to operate with good responsiveness during normal engine operation, but resists excessive slack in the chain, and prevents backlash and fluttering, during engine start-up.

Abstract: In a chain drive for an internal combustion engine, said chain drive comprising a driving wheel (2), a driven wheel (3), an endlessly circulating chain (1) that connects the driving wheel (2) and the driven wheel (3), a chain tensioner (9) acting on the slack strand (7) of the chain (1), and an additional tensioning device (12) that is loaded by a spring (13) and acts on the tight strand (6) of the chain (1) while being arranged for pivoting, a further driven wheel (4) is installed in the tight strand (6) of the chain drive and is used as a driving wheel for a rotatably mounted compensating shaft for offsetting free forces and moments that occur during operation of the internal combustion engine.

Abstract: A continuously variable transmission including a drive element rotatable about a drive axis, an output element rotatable about an output axis parallel to the drive axis, and an adjusting mechanism with which the drive axis and the output axis can be laterally offset from each other. Coupling elements operate between the drive element and the output element and are spaced from each other in the peripheral direction of the drive element and output element for transmitting torque between the elements. The coupling elements change the movement of a peripheral region of the drive element faster than that of the output element so that forces acting on the coupling elements from the drive element and the output element lie substantially in a common plane that extends perpendicularly to the axes of rotation. The continuously variable transmission can be incorporated into a transfer case for an all-wheel drive system.

Abstract: This invention provides a chain tensioner that is compact, excellent in operation, easy to maintain and handle and low in manufacturing cost. This chain tensioner has a tubular housing 1 having a bottom, a plunger 3 installed in the inner periphery 1a of the housing so as to smoothly slide inside the housing, a return spring 5 providing the plunger 3 with a force pushing outward, a plurality of latching grooves 33a–33d formed on the outer periphery of the plunger 3, a resister ring 7 capable of locking in the latching grooves, and a check valve 6 that is mounted on the bottom of the housing inner periphery 1a, provides the housing inner periphery 1a with operating oil and prevents its reverse flow. The range of backward movement of the plunger 3 is limited by mating the resister ring 7 locked in the latching grooves 33a–33d with a first stopper 21 formed on the housing inner periphery 1a.

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

Abstract: A belt tensioner for a power transmission belt may be provided that operates on an endless path and that utilizes asymmetric motion control. The belt tensioner may have an arm with a belt engaging section and a drum section, a support member for securing the tensioner relative to the belt, where the arm pivots on the support member, and a tension 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 may have a fluid filled chamber inside a portion of the drum section of the arm and a valve pivotally attached to the tensioner so that the valve extends across the fluid containing chamber.

Abstract: In a belt tensioner, a cylinder is mounted to a side of a stationary member positioned in an upper side. A plunger is mounted to a side of a pulley positioned in a lower side. An outer tube sectioning an oil reservoir forming a gas chamber in an upper portion is provided in an outer periphery of the plunger and the cylinder. A first oil passage communicating the gas chamber with a high pressure oil chamber is provided in an upper portion of the cylinder. A second oil passage communicating the high pressure oil chamber with the oil reservoir is provided in the plunger. An orifice hole is provided in the first oil passage. A first check valve closing at an expansion time is provided in the first oil passage, and a second check valve closing at a compression time is provided in the second oil passage.

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: An adjusting device provided on a transmission belt to adjust the tension of the transmission belt. The adjusting device includes a housing and a fastener fixed on the housing, the fastener engaging the transmission belt so that there is no relative displacement between the fastener and the transmission belt. A sliding mechanism is disposed on the housing and is capable of sliding in a linear direction on the housing, the sliding mechanism engaging the transmission belt so that there is no relative displacement between the sliding mechanism and the transmission belt. An elastic device is fixed to the housing at a first end and fixed to the sliding mechanism at a second end for maintaining proper tension in the transmission belt.

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, in which an outer body and an inner body, which can deal with a tensioner mounting form required by various engines and a tension-imparting function, can be assembled. The inner body and a movement backward preventing mechanism, which form an inner body unit, can be unitized in a shape by which press-fitting and assembling is easy, and its efficient assembling production can be performed. A body 22 of a tensioner 21 is composed of outer and inner bodies 23 and 24 of different members. The outer body 23 is provided with a tensioner mounting means and an inner body fitting hole 23a. The inner body 24 is provided with a plunger accommodating hole 24a into which a plunger 26 biased by a compression spring 27 was slidably fitted, and a movement backward preventing mechanism 32 for preventing the backward movement of the plunger 26 is incorporated into the inner body 24.