Abstract: A ratchet tensioner has a plunger retractably mounted in a housing and urged by a spring in a direction to project outward from the housing, and a ratchet pawl pivotally mounted on the housing and having a first prong normally engaged with one of ratchet teeth formed on the plunger so as to prevent backward motion of the plunger. The ratchet pawl also has a second prong spaced a predetermined distance from the first prong in the backward direction of the plunger and engageable with a second rack tooth to release meshing engagement between the first prong and the rack tooth when the plunger is moved forward due to a slack of a timing chain used with the tensioner. In order to maintain a predetermined amount of backlash between the first prong and the rack teeth, the rack teeth have a height greater than a half pitch of the ratchet teeth.

Abstract: A motive assembly for moving a plurality of warp yarns (32) in a loom between upper and lower shed positions, the motive assembly including a plurality of selectively controllable ultrasonic cyclic motors (10), each of which is drivingly connected to one or a group of said warp yarns (32) for moving the warp yarn(s) (32) between upper and lower shed positions.

Abstract: A closed hydraulic tensioner has a high-pressure chamber, a low-pressure chamber and a reservoir that are previously filled with an oil sealed in the hydraulic tensioner. The hydraulic tensioner further has a pressure chamber disposed next to said reservoir with a movable member disposed therebetween so as to displace the movable member toward the reservoir to thereby pressurize the oil inside the reservoir. The pressure chamber is supplied with an oil from the exterior of the tensioner.

Abstract: A ratchet tensioner includes a plunger locking and releasing mechanism for selectively locking and releasing a plunger relatively to a ratchet pawl pivotally mounted to a housing. The plunger locking and releasing mechanism has a lever-like pin contact portion formed integrally with a ratchet pawl body, a pin member-fitting hole formed in two opposed side walls of the housing in registry with the lever-like pin contact portion such that there being two pin-accommodating spaces defined between the lever-like pin contact portion and an inner peripheral surface of the pin member-fitting hole on opposite sides of the lever-like pin contact portion, and a pin member removably and selectively inserted in the pin-accommodating spaces.

Abstract: A tensioner includes a plunger stopper mechanism for holding a plunger in an inoperative position in which the plunger is retracted into a cylinder chamber formed in a tensioner body. The plunger stopper mechanism has a radial pin hole formed in the tensioner body and communicating with the cylinder chamber, an annular pin stopper groove formed in a circumference of the plunger, and a stopper pin removably inserted through the radial pin hole into the annular pin hole. The radial pin hole has a center line extending parallel to a tangent to the bottom of the annular pin stopper groove and offset from the tangent toward an open side of the annular pin stopper groove, and the annular pin stopper groove has a depth slightly greater than a diameter of the stopper pin, so that a side face of the stopper pin is held in contact with the bottom of the annular pin stopper groove.

Abstract: A tensioner has a substantially U-shaped stopper pin hooked at opposite end parts on a tensioner body and part of a plunger, respectively, to keep the plunger in a retracted position against the force of a spring before the tensioner is mounted to an engine body at an appropriate position relative to a power transmitting chain.

Abstract: A tool pot separation type chain for use in a tool magazine includes a plurality of tool pots, and a plurality of pairs of laterally spaced link plates each adjacent ones of which are connected to each other by a connection pin. Each of the pairs of link plates has a tool pot receiving section for removably receiving one of the tool pots therein. Each of the tool pots has a pair of bearings mounted thereon such that outer races of the bearings are movable in rolling contact on a guide rail or a tool pot jumping-out preventing rail provided in an opposing relationship with the guide rail in the tool magazine. With this construction, the tool pot separation type chain is able to minimizes the traveling resistance thereof during carrying of the tool pots to reduce the driving force, prevent abrasion of the tool pots and the rails and suppress generation of noise and also facilitates a carrying in or carrying out operation of each tool pot at a tool pot loading/unloading position.

Abstract: A tensioner lever for chain drives has an internal space formed therein for accommodating within it at least a coiled portion of a torsion coil spring. The internal space has an opening for enabling the torsion coil spring to be assembled in the internal space. The lever body further has a boss disposed inside the internal space. The boss has an axial hole through which a pivot shaft extends and an outer peripheral surface around which the coiled portion of the torsion coil spring is loosely fitted, the axial hole and the outer peripheral surface being concentric with each other. The tensioner lever of the foregoing construction requires only a small space for installation to a mount surface and can be easily and speedily assembled onto the mount surface.

Abstract: A shoe for a tensioner device and chain guide is formed a polyamide 66 or 46 resin mold product having a relative viscosity more than 100 (90% formic acid method). A skin layer of the resin mold product includes a non-spherulite area less than 100 &mgr;m in thickness. The shoe excels in the wear resistance, slidability, impact resistance, heat resistance, and oil resistance, has a high degree of freedom in the shape, and excels in the workability.

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

Abstract: Cam follower includes a cantilevered stud, and a bearing unit mounted on a head portion of the stud and having rollers and an outer ring. The outer peripheral surface of the outer ring constitutes a cam-driven surface. The cam-driven surface includes a central load-bearing region substantially parallel to the axis of the cantilevered stud, and a couple of load-reducing bearing regions indented radially inward from the central load-bearing region and located on opposite sides of the central load-bearing region axially symmetrically to each other. Mechanical stress acting on the inner surface of the outer ring, outer surface of the roller and outer surface of the stud's head portion presents a maximum intensity level at their respective points corresponding to a point of the outer ring which is subjected to maximum mechanical contact stress from a cam.

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

Abstract: A toothed belt particularly suitable for use in general industrial machineries includes a cured rubber belt body, a tensile member embedded in the belt body, and a tooth fabric adhered to the surface of teeth of the belt body. The belt body is formed primarily from a vulcanizable rubber composition containing hydrogenated nitrile rubber and zinc polymethacrylate. The zinc polymethacrylate and the hydrogenated nitrile rubber are blended together in a ratio of from 22:78 to 45:55 parts by weight. To the vulcanizable rubber composition, a vulcanizing agent comprised of peroxide and a reinforcer comprised of carbon black are added, and a mixture is vulcanized and pressed or otherwise molded to form the afore-said cured rubber belt body with the tensile member embedded therein. The tensile member is made of high-strength glass fibers. The glass fibers preferably have a resorcin-formalin-latex layer and an overcoat layer both formed thereon.

Abstract: An electronic jacquard including a plurality of elongate heald hooks (1a, 1b) movable longitudinally between upper and lower shed positions and a plurality of electrically operable selection devices (50) for co-operation with the heald hooks (1a, 1b) for selectively retaining the heald hooks (1a, 1b) at one of said shed positions, each selection device including a latch (4a, 4b) movable between a latched position and a non-latched position, the latch (4a, 4b) when at said latched position being capable of latching engagement with the heald hook (1a, 1b) in order to retain it at said shed position, and an ultrasonic cyclic motor (55), preferably a piezo-electric motor, drivingly arranged to move the latch (4a, 4b) from its non-latched position to its latched position.

Abstract: A sprocket has a central through-hole for attachment of the sprocket to a rotating shaft, a boss coaxial with the through-hole, and teeth on the periphery of the sprocket. The boss has a cylindrical outer surface coaxial with the through-hole and having stepped small-diameter portions formed at opposite ends of the boas. A cushion body is in the form of a disk having an eccentric through-hole and includes an annular bearing having a cylindrical inner surface defining the through-hole, and a cushion member press-fitted over a cylindrical outer surface of the bearing. The bearing is slidably mounted on the cylindrical outer surface of the boss on each side of the teeth, and a ring-like flange is press-fitted over each stepped portion of the boss so as to prevent the cushion body from moving in the axial direction of the sprocket while allowing sliding movement of the cushion body relative to the boss.

Abstract: A cylindrical roller bearing includes a plurality of cylindrical rollers disposed between a circular outer race and a circular inner race without using a retainer. The inner and outer races are devoid of annular flanges extending radially from opposite axial ends of the races for controlling the position of the cylindrical rollers in an axial direction. A pair of thrust bearing plates are disposed on the opposite sides of the outer race for controlling the positions of the outer race and the cylindrical rollers in the axial direction. One or more of the cylindrical rollers are formed shorter than the other cylindrical rollers. With this arrangement, a skew of one or more of the cylindrical rollers, which may occur when the outer race is subjected to an axial load, is taken up by circumferential gaps formed between the shorter cylindrical roller and adjacent cylindrical rollers at opposite ends of the shorter cylindrical roller.

Abstract: Separation apparatus and method for separating magnetic and/or magnetically-labeled particles from a test medium in a reaction chamber which incorporates baffles, a spinner, a stirrer, or a plunger operable to be displaced along a collection surface to define a narrow flow path through which the particle-laden test medium must flow. The collection surface is a thin-walled non-magnetic material having a plurality of magnetic pole faces positioned therearound. Test medium within a reaction chamber is caused to flow past a collecting surface, and a high-gradient magnetic field is applied to the surface to capture magnetically responsive particles in the test medium. The particles are deflected toward the collection surface in the flow path for the test medium. The narrow flow path assures that substantially all of the particles pass within the high-gradient magnetic field along the collection surface.

Abstract: Two cam-bearing holders of an indexing drive are bolted to opposed side walls of a housing in such a way that respective positions of the cam-bearing holders are adjustable in a plane orthogonal to an axial direction of the cam shaft along the side walls. Each of the cam-bearing holders has a first reference surface for positioning the cam-bearing holder relative to a positioning reference surface of the output shaft in the axial direction of an output shaft and a second reference surface for positioning the cam-bearing holder in a direction orthogonal to the axial direction of the output shaft. With such novel arrangements, there is achieved an improved cam-positioning mechanism for the indexing drive which can accurately adjust a meshing engagement between the cam and roller followers of the output shaft and thereby allows the indexing drive to be assembled with greatly increased accuracy.