Abstract: A belt clutch control apparatus is disclosed having a control handle and linkage means for selectively controlling the transmission and power from a driving pulley to a driven pulley through a driving belt. In a preferred embodiment, the apparatus is specially adapted to control the operation of the cutting blades on a riding mower. The linkage includes an undercenter connecting link for transmitting rotational movement of the control shaft to a bellcrank, which engages a tension spring to operatively move an idler pulley between engaged and disengaged positions relative to the driving belt. The undercenter link moves exclusively between first and second undercenter positions, and is never forced into an overcenter position. An assist spring is provided for securing the undercenter link in both its on and off undercenter positions, thereby relieving the idler pulley spring for this purpose.

Abstract: A power transmission system for the transmission of power or the transmission of movement from a first device to a second device comprises an endless flexible belt for transmitting power from a first power driven device to a second device for receiving the power. Such a belt can preferably be a toothed belt, also called a synchronous belt, as used, for example, on internal combustion engines for the synchronous propulsion of cam shafts at the cylinder head, and which belt has a construction capable of withstanding the operating environment for which it is intended.

Abstract: An improved tool is disclosed for use in aligning pulleys. The tool has a shaped configuration with multiple engaging pads adapted to align the pulleys with in about 0.2 degrees.

Abstract: A tensioning device for an elevator air cord that forms a loop has: a support having a relatively accessible first surface and a relatively inaccessible second surface; a holder on the second surface for fixedly holding a first end of the air cord; a tensioning device on said second surface for holding a second end of said air cord such that the tension of the loop of air cord may be adjusted; and key communicating between the first and second surfaces for manipulating the tensioning device to adjust the tension of the air cord loop.

Abstract: A continuously variable transmission having a belt ratio measurement system. The continuously variable transmission contains a moveable sheave and a fixed sheave. The measurement system includes two tone wheels and pickups. The first tone wheel is mounted to the fixed sheave with a corresponding first pickup mounted proximate thereto. The second tone wheel is mounted to the moveable sheave with a corresponding second pickup mounted proximate thereto. The second tone wheel has angled teeth so that the signal sensed in the second pickup varies in relation to the axial position of the moveable sheave. By comparing the signal sensed by the first pickup with the signal sensed by the second pickup, the axial position of the moveable sheave, and thus the belt ratio of the transmission, may be determined.

Abstract: A rotary arm sewage treatment bed has its rotary arms driven by an electrical drive system. The drive system comprises a driving ring (7) to which the arms are secured. The drive ring is driven by a friction belt (8), from a drive wheel (10). The drive wheel (10) is mounted on a pivoted carriage (18). A compressor (30) operates a piston/cylinder (36)/(34). In normal use, the piston (36) acts on the carriage (18) to cause tensioning of the belt (8), and thus enable drive. In the event of a supply failure, the piston is retracted by a return spring and the drive is disengaged, the carriage being pivoted such that the drive wheel is no longer in a position to tension the belt (8). The arms are then free to rotate under the reaction force of the sewage emitted, until the power supply is restored.

Abstract: A variable inverted pulley circumference mechanism supported by an external mechanism that locates the pulley halves. Power transfer takes place via either a combination of a variable pulley located inside the variable inverted pulley, working together with fixed planet wheels, or with innovative variable span planet mechanisms working together with a traditional sun wheel or a variable pulley in place of a traditional sun, wherein the variable circumference mechanism consist of one or more surfaces, so that part of the surface is used as needed to form the circumference, and unused parts of the surface is stored opposite of a contact surface of the circumference.

Abstract: The air system on a harvester includes a fan with a remotely actuatable belt tightener assembly controlled by an electric acme thread actuator. A control circuit connected to the actuator includes a fan control switch and an engine speed switch for preventing fan actuation above a preselected engine speed. The actuator retains the belt tightener in the engaged position when the engine is switched off so that belt inspection and tension adjustments can be made easily. The tightener assembly includes simple tension indicating and adjusting structure for providing easy and accurate belt adjustments when the engine is off.

Abstract: In an internal combustion engine, there is arranged a belt transmission for driving an accessory device. In this connection, deflection members are arranged so that the drive belt for its driving bears against, for example, the flywheel of the engine. The deflection members are arranged so that the area enclosed by the drive belt lies outside the area which encloses the axis of rotation of the flywheel. By virtue of the fact that consequently the drive belt can be mounted without the drive belt needing to cross the axis of rotation, the belt transmission can simply be arranged at the rear side of the engine. This means that the axial extent of the engine can be reduced.

Abstract: A belt-drive tensioning system for a motor drive positioning system, especially for X-Y digital plotters. The tensioning system employs spring-loading involving motion along only one translational direction to accurately preset and maintain constant the desired belt tension. Preferred embodiments to provide a self-contained modular unit include a dual plate assembly in roller-bearing relationship, and the use of V-shaped mounting springs.

Abstract: A dancer pulley assembly includes a first horizontal plate having an upper surface and a lower surface, a swing arm having a proximal end pivotally mounted to the first horizontal plate on the lower surface thereof and being pivotal about a vertical pivot axis A, a second horizontal plate having an upper surface and a lower surface and being spaced vertically above the first horizontal plate by at least one vertical support, a pulley shaft having an upper end and a lower end, the lower end being mounted on a distal end of the swing arm and extending upwardly through an arcuate opening formed in the first horizontal plate, a dancer pulley rotatably mounted on the pulley shaft between the first and second horizontal plates for rotation about a vertical rotation axis B and being swingable on the swing arm through an arc defined by a distance between the pivot axis A and the rotation axis B, means for guiding the upper end of the pulley shaft during swinging motion of the dancer pulley, and means for adjusting th

Abstract: An apparatus for tensioning a belt or cable, reeved about first and second pulleys or sprockets, both mounted for rotation on supports. The apparatus includes a base plate and a post mounted through a closely-sized aperture in the base plate. An arm is mounted to the post at a mounting point at one end of the arm, such that the arm is rotatable about the post with respect to the base plate. An idler sprocket is rotatably attached to the arm at a point spaced apart from the mounting point of the arm, near the opposite end, and positioned so as to be engageable with the belt or chain. Engaging pins are positioned on the arm at a point near the idler sprocket. The base plate has corresponding holes for engaging the engaging pins on the arm in a plurality of positions with respect to the base plate.

Abstract: An adjustable belt retainer is provided for use with a belt driven mechanism, such as an auxiliary blower for a mower deck. The retainer allows quick and easy adjustment between a belt retaining and a belt removal position. Its L-shaped with one leg being slidably mounted to the housing, the other leg extending adjacent the belt near its contact with the pulley. A releasable stop is provided between the housing and retainer being biased towards engagement to maintain a retainer in its belt retaining position. A finger handle is provided to allow the operator to disengage the stop easily without the need for tools and guide surfaces are provided to allow quick and easy sliding adjustment of the retainer between its two positions.

Abstract: A torque transmission system for effecting a driving connection between laterally spaced driving, and driven shafts. A fist wheel is mounted on the driving shaft and a second wheel is mounted on the driven shaft. Each of the wheels have substantially identical pitch diameters. An endless flexible torque transmitter operatively connects the first and second wheels. A traveling insert band circumscribes and operatively engages one of the wheels at a time, and when the traveling insert band engages one of the wheels, the insert band is located radially inwardly of the endless flexible torque transmitter. The traveling insert band has leading and trailing ends located in substantially circumferentially opposed juxtaposition when the traveling insert band operatively engages one of the wheels. Mechanisms are also provided selectively to derail the leading end of the traveling insert band from that wheel operatively engaged thereby.

Abstract: The V-belt drive has a V-belt (R), revolving endlessly around a drive pulley (A) and at least one driven pulley (C) and a back chucking roller (D) is associated with the V-belt on the slack side (R1). The back chucking roller (D) is preceded in the belt travel direction (RL) by a profiled idler pulley (E), and both rollers (D, E) form a clamping unit (SE) that is subjected to clamping force action and acts near the driven pulley (C). In every position of the clamping unit (SE) the entry and exit point (G1 and G2, respectively) of the V-belt (R) at the profiled idler pulley (E) are located before, in the belt travel direction (RL), or at best coincide with the entry point (K1 and K2, respectively) of the back chucking roller (D).

Abstract: A mounting structure for drivingly connecting a belt driven attachment such as an auxiliary blower to a mower deck or similar implement. The connecting structure includes a pivot and sleeve arrangement between one end of the blower and the mower deck for quickly and easily positioning the blower on the mower deck. The pivot then allows for the blower to be swung around adjacent to the mower deck to permit a latching mechanism to be engaged between the mower deck and the blower. The combination latching and belt tensioning mechanism permits generally simultaneous belt tensioning for belt driven blowers as the rear of the blower is latched to the mower deck. Should the latch not be aligned and, therefore, not secure the mower to the blower deck, provision is made for the belt tensioning arrangement to not engage the blower attachment adequately with the mower's belt drive.

Abstract: A friction device, in particular for belt tensioners for driving auxiliary units of internal combustion engines, comprising a housing (1), a pressure disk (17, 20, 21) and arranged therebetween, a friction disk (19), the pressure disk (17, 20, 21) and the friction disk (19) being rotatable with respect to each other and an axial force acting between the pressure disk (17, 20, 21) and the housing (1) via the friction disk (19), characterized in that at least one end face of the friction disk (19) is in contact with a protruding (convex) support surface (22, 23) extending towards it.

Abstract: Disclosed is an actuator having a frame in which a drive source and a slider displaced under the action of the drive source are held, and an actuator arrangement comprising a plurality of actuators connected to each other by connecting devices. A beam member, which constitutes the frame, has a concave portion defined in a side thereof and the drive source is held in the concave portion. A slider base is held in the concave portion and includes the slider displaced along the concave portion. A cover is used to cover the concave portion defined in the beam member. The beam member has grooves defined in respective outer sides thereof, which have substantially T-shaped cross sections and enable other beam members to be mounted to the beam member. The grooves are defined along the longitudinal direction thereof so as to be substantially identical in structure to one another.

Abstract: Belt tensioning apparatus particularly suited for maintaining the proper tension in a drive belt for providing reciprocal linear movement for scanning apparatus wherein a coiled spring having a first hook portion extending from one end thereof and a second hook portion extending from the other end thereof is located so that a portion of the drive belt passes under the first hook portion, around the coiled spring and under the second hook portion to apply a relatively constant tensioning force on the drive belt.

Abstract: A gardening utility machine having a counter-rotation twin shaft system can perform multiple types of work required for gardening (tilting, soil removal, weeding, racking and shredding of leaves), snow/ice removal and for power de-thatching and mowing of lawn grass. This can be done by exchanging attachments on the counter-rotating twin shafts: if tines are installed on the twin shafts, soil tilling, weeding can be done; if auger blades with or without digging bits are in place instead, the machine can simultaneously till and remove soil or can remove ice/snow, or rack and shred leaves; if the front shaft is installed with a spiked roller and the rear shaft, a shearing reel, then the machine can power de-thatch and mow grass at the same time, and, additional grass clipping mulching ability can be performed if a fan blower equipped with a mulching fan blade and a retractable bedknife is in place.

Abstract: A tensioner lever for applying tension to an endless power transmission in the form of a chain, belt or the like, comprises an elongated arm made of aluminum and having I-shaped cross-sections in section planes transverse to its direction of elongation.

Abstract: An adjustment device for adjusting a lever arm located inside a machine frame wherein the lever arm is pivotally mounted to the frame at a first location and is spring biased against a stop at a second location of the frame. The device comprises a resilient sleeve having a shank portion adapted to extend through an aperture in the frame to act as the stop, and a head portion of larger diameter then the diameter of the aperture in the frame. The shank portion has a threaded section and a non-threaded section, the non-threaded section having a length greater than the frame thickness at the aperture, wherein the lever arm pivots as a screw extending axially through the sleeve is turned in the threaded section.

Abstract: A pretensioner for a vehicle seat belt system comprises a casing, a drive mechanism including a spring having an operating end and an output member coupled to the operating end, a trigger mechanism for restraining the drive mechanism in a preloaded state and including a toggle linkage engaged between the casing and the drive mechanism, and a sensor mechanism having a output member for releasing the trigger mechanism upon acceleration in excess of a predetermined value by causing articulation of the toggle linkage about a pivot axis such that it ceases to be engaged between the drive mechanism and the casing and thereby releases the drive mechanism from the preloaded state.

Abstract: An anti-chain wrap device for bicycles has a short mounting plate with large fastener holes for universal adjustments in the plane thereof and a clamp plate fastener with conventional fastener holes. Chain lifter fingers for contacting chain stuck on a chainring have portions bent out of the plane thereof to avoid interference on chainrings having extra teeth thereon. The fastener plate may have a fender mounting tab thereon as well as a control cable guide.

Abstract: A chain adjusting device for vehicles having a rear fork pivoted to a main vehicle frame with an intermediate shaft and a driving shaft rotatably mounted to the rear fork. A primary chain coupling the intermediate shaft with the output shaft of an engine and a secondary chain coupling the intermediate shaft with the driving shaft directs power from the engine to a drive wheel. The intermediate shaft is mounted to the rear fork by means of a bearing assembly mounted to a bracket located between parallel cross members of the rear fork. An adjustment bracket is provided to mount arms associated with the bearing assembly in position.

Abstract: A hydraulic control apparatus for controlling a belt-and-pulley type continuously variable transmission of a motor vehicle having an engine, which transmission includes a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of a transmission belt. The hydraulic control apparatus includes an engine-output detecting valve for generating an engine output pressure indicative of a currently required output of the engine, a solenoid-operated valve for regulating a modified engine output pressure based on the engine output pressure generated by the engine-output detecting valve, and a pressure regulating valve for regulating the belt tensioning pressure based on at least the modified output pressure. The modified engine output pressure is obtained so that the belt tensioning pressure is controlled to an optimum level.

Abstract: A positioning device for preventing an endless belt passed over a plurality support rollers from being shifted to either of opposite sides in the axial direction of the rollers. A pair of forcing elements are located at both ends of at least one of the support rollers for forcing back, when the belt is shifted toward either of opposite ends of the support roller to contact the end of the latter, the belt toward the center of the roller in the axial direction of the roller. The forcing elements each are implemented as a plurality of spaced flanges. The maximum diameter of the flanges sequentially increases from the innermost flange to the outermost flange in the axial direction of the roller. The plurality of flanges may be replaced with a single spiral flange.

Abstract: In a chain thrower mechanism of a bicycle derailleur gear mechanism a parallelogram linkage is formed from plastics material at least part of the joints of which are plastic film hinges.

Abstract: A device for applying tension to an endless chain, belt or the like comprises a ratcheted plunger having a substantially planar face disposed in substantially perpendicular relationship to the axis of movement of the plunger, and a chain or belt-engaging lever having a pad with a convex face arranged to contact the substantially planar face of the plunger. Vibrational forces exerted by the lever on the tensioner are substantially parallel to the axis of movement of the plunger, so that wear of the plunger and plunger guide are significantly reduced.

Abstract: A lead frame conveying apparatus comprises a driving force converting unit for transmitting to a frame receiving arm a horizontal reciprocating linear motion of an elliptic motion of a timing belt place over two timing pulleys between the centers of the timing pulleys and converting semicircular motions at both ends of the horizontal reciprocating linear motion into vertical reciprocating linear motions by employing rolling contact for absorbing the horizontal component thereof and transmitting the vertical reciprocating linear motion to the frame receiving arm so as to put the frame receiving arm into a rectangular motion. The apparatus thus requires only one induction motor as a driving device.

Abstract: An engine equipped with driving belts is provided with an automatically regulated belt-stretching device, arranged in the vicinity of one belt, mounted on a support fixed to the engine. The device includes a pin extending from the support and defining a longitudinal axis, the pin being provided with a pair of shoulders at a distance from one another, between which two bushings are inserted. The bushings are adaped to define, together with the pin, a pair of housings. Springs capable of displacing the bushings relative to the shoulders and to the longitudinal axis of the pin are housed in the respective housings. A bearing which rotates in contact with one belt is provided on the outer surface of each bushing.

Abstract: A belt driving system having at least one roller for adjusting creep within a plurality of rollers. Creep detecting means provided at one end of the creep adjusting roller is rotated by torque of a flat belt in contact with the creep detecting means. Biasing means for biasing the flat belt toward the creep detecting means and roller-end displacing means for converting the torque of the creep detecting means to displacement of the end of the creep adjusting roller toward a predetermined direction so that the flat belt is moved to the direction contrary to the creep caused by the biasing means are provided. When the flat belt creeps, the creep contrary to the original creep is caused by the roller-end displacing means, and thus the original creep is compensated. Consequently, stable running of the flat belt is obtained and clear pictures of the electrophotographic machine can be also obtained.

Abstract: The inventive device includes a support shaft having a longitudinal axis with a locus that does not change, including when the shaft is positionally rotated about such axis. A collar is mounted on the shaft for supporting an idler pulley having an axis of rotation. An indexing plate is also mounted on the shaft for maintaining a selected position of the collar, the angular position of which is adjustable. An indexing surface is in position-affecting relationship to the collar and defines a plane oriented at an angle with respect to the shaft axis. This angle is adjustable for selecting the position of the collar. The device permits the locus of the axis of rotation of the idler pulley to be selected to maintain alignment of a belt with a driving pulley, thereby preventing such belt from becoming disengaged from the driving pulley.

Abstract: An internal combustion engine having a power generating device, and a transmission link connecting the power generating device to an accessory operated by the power generating device, the transmission link being tensioned by a tension adjusting device which elastically presses a tension pulley against the flexible transmission link by the electric deformability of a deformable parallelepiped solid constituted by a pair of elements formed of composite flexible strips held parallel, and separated, by the permanent fixing of their extremities in a bearing holder block and in an adjustable fastener, the flexible strips possibly supporting a means to modify the flexibility of the elastic tension device which may include a means to damp the vibrations of the flexible link.

Abstract: A drive chain assembly for vehicles having two chains, an idler sprocket, and a thrust link or strut. The first chain extending from the vehicle motor to the idler sprocket. The second chain extending from the idler sprocket to a driven axle sprocket. The second chain extending downwardly at a substantial angle from the driven axle to the idler sprocket and the idler sprocket supported on a mounting member which pivots on the same axis as the driven axle itself. The thrust link is pivotally attached at one end to the chassis of the vehicle near the engine and at its other end to the mounting of the idler sprocket. This strut forms one of the long side of a parallelogram linkage. The first short side of the parallelogram linkage is the distance between the pivot point at the engine end on the chassis for the strut and the engine sprocket. The second long side of the parallelogram is the first drive chain itself.

Abstract: A resilient rotational bias device that is continuously adjustable to supply any preselected rotational bias force to a shaft, within a wide range, by rotation of a multi-step shaft retention member, usually a gear, by a simple drive such as a worm gear that engages the shaft retention member; the shaft retention member an the drive are mounted in a housing that is affixed to one end of a resilient torsion member, the other end of the torsion member being affixed to a stationary frame. All elements of the device other than the torsion member, but including a connector for connecting the shaft retention member to the end of a biased shaft, are mounted in the housing. All elements of the device, except a drive shaft for th worm gear, are usually formed of the same molding resin, preferably polyurethane.

Abstract: A continuously variable transmission system having a primary pulley, a secondary pulley, a driving belt disposed therebetween, and a torque converter disposed between an engine and the primary pulley. The pulleys each have discs movable by applying an hydraulic pressure to control the tension in the belt such that during acceleration from a stationary position the tension is temporarily increased to a level above a maximally allowable tension being determined on the basis of the statistic average of the expected number of revolutions at the end of the life of the belt.

Abstract: A work holding apparatus for holding a work to be coated such as a bumper for an automobile while rotating the same is disclosed. The work holding apparatus includes a frame mounted for rotation on a support member, a work holding member mounted on the frame by means of a support bar extending perpendicularly to the longitudinal direction of a work, and a drive mechanism for rotating the frame. An axis of rotation of the frame is disposed substantially at a central position of a work held on the work holding member along a width of the work in a direction perpendicular to the longitudinal direction of the work.

Abstract: A chain-type power transmission mechanism, having first and second sets of sprockets, each set of which has a sprocket provided on both a drive shaft and a driven shaft. A first chain extends over and between the first set of sprockets, and a second chain extends over and between the second set of sprockets. The two sprockets provided on at least one of the shafts are relatively changeable in rotational position whereby the forward side of one chain and the backward side of the other chain are tensioned.

Abstract: A variable inverted pulley mechanism supported by an external mechanisms that located the pulley halves. Power transfer takes place via either a combination of a variable pulley located inside the variable inverted pulley, working together with fixed planet wheels, or with innovative variable span planet mechanisms working together with a traditional sun wheel or a variable pulley in place of a traditional sun.

Abstract: An audio control system including a unique pulley assembly for automated linear movement of the device is disclosed. The pulley assembly includes two pulleys with two different diameters and parallel axes of rotation. A capstan with a different axis of rotation than either of the pulleys is disposed between the two pulleys. A string is wound around the capstan and the circumferences of the pulleys. The diameters of the pulleys are selected such that the turns of the string on the pulley do not overlap.

Abstract: A swing saw for cutting logs to length prior to cutting into lumber or plywood veneer is provided with a rotary arbor shaft coupled to a secondary drive shaft through a drive chain, the secondary drive shaft being coupled to an electric drive motor through drive belts. The secondary drive shaft is supported on laterally spaced bearings which, in turn, are maintained parallel by adjustment screws mounting rotatable sprockets which are coupled together through a secondary chain by which adjustable rotation of one of the sprockets effects simultaneous adjustable rotation of the other sprocket to precisely the same degree and direction. The adjustment screws thus are moved longitudinally in the same direction and precisely the same distance, and therefore the axis of the secondary drive shaft is maintained precisely parallel to the axis of the arbor shaft. The secondary drive shaft is secured by clamp plates when adjusted. Both shafts are mounted on a hollow housing in which the drive chain is contained.

Abstract: A portable printer including paper feed apparatus for utilizing sheet, roll or continuous form paper. The paper feed apparatus having pin feed drive members and friction rollers for feeding all three forms of paper. The printer also includes apparatus for selecting printing different character pitches to reduce the memory capacity required. A method is provided for operating the printer to obtain alignment of the paper feed drive motor prior to printing.

Abstract: A tensioning device is provided for selecting and imparting torsional bias to a shaft and simultaneously providing a shock absorbing mechanism. The device includes a resilient elastomeric biasing member in the form of a web extending radially between the shaft and an actuator member. The first end of the biasing member is connected to the shaft for conjoint rotation therewith and the second end of the biasing member is connected to the actuator member. A locking mechanism selectively connects the actuator member to a fixed frame after a torsional biasing force is imparted to the shaft.

Abstract: An improved mounting for spaced band wheels about which the sealing bands of a band sealer move is achieved by mounting at least one of the band wheels carrying each band from a double ended cylinder movable longitudinally with respect to the inter-band wheel distance to thereby allow adjustability in the distance between the drive and idler band wheels and, in turn, modulate the tension in the band and with the shortest wheel distance allow easy removal and replacement of the band.

Abstract: In a pre-mounted tensioning device the fastening bolt is covered by the idler wheel. The fastening bolt is serviced through a recess provided in the wheel surface. A pre-mounted unit is created through the insertion of a fastening bolt whose head is pushed by spring elements against the wheel surface, thus preventing the idler wheel from turning and forcing the recess to coincide with the fastening bolt.

Abstract: The invention relates to a method and apparatus for installing belts on belt drives of the type where the belt is tensioned on the belt drive with the use of an adjustable tensioning device. In order to avoid a rapid slacking of the adjusted belt tension, the belt is driven in a preconditioning device at a defined tension value for a predetermined period or time. The belt is preferably installed on the belt drive immediately after removal from the preconditioning device. The preconditioning device includes a drive motor for driving a first pulley, a second pivoted pulley, and a tensioning device for tensioning the belt while it is carried by the pulleys.

Abstract: Wheel suspension for a wheel driven by an endless transmission, characterized in that the rocking point (11), apart from the driven wheel (2), of the rocking arms (9-10) are connected by levers (13-15), (28-29). With respect to a part of the vehicle of which the driven wheel is a part, these levers ensuring that during the rocking of the levers (9-10) aforementioned rocking point (11) is always located on an axis drawn through shafts (7-11-3) of the transmission (6-5-4), in which the distance between shafts 3 and 7 is constant or virtually constant.

Abstract: A self adjusting tensioning system for a variable transmission. An endless belt is advanced by and supported on a pair of spaced apart, variable diameter, sheaves which are independently movable between reduced and enlarged configurations and which result in the belt assuming different paths. A pair of rollers are rotatably mounted at fixedly spaced locations on an elongated carrier member. One of the rollers is actively biased into engagement with the belt by a compression spring assembly. A cam surface on the carrier member proximate the other of the rollers is slidable along a fixed contoured supporting surface and passively assures engagement of the other of the rollers with the belt. As the ratio of the transmission changes with changed diameters of the sheaves and the belt thereby assumes a changed path, the belt is effective to automatically move the rollers therealong so as to maintain a substantially constant tension in the belt.

Abstract: In a wrapping type transmission structure for internal combustion engines, provided with a first wrapping type transmission system which includes a first tensioner urged into press contact with a first endless power-transmitting belt and which is disposed on a side wall of an engine body, and a second wrapping type transmission system which includes a second tensioner urged into press contact with a second endless power-transmitting belt and which is disposed at a location remoter from the engine body than the first wrapping type transmission system, a support shaft is fixed to the engine body and is inserted through the first and second tensioners which are relatively movable in a plane perpendicular to the axis of the support shaft, while permitting the movements of the tensioners in directions of press contact with the first and second transmitting belts. This enables the tensioner arrangement to be compact and permits an increase in freedom for disposition of the transmission systems.