Abstract: A track system for traction of an off-road vehicle such as a snowmobile or an all-terrain vehicle (ATV). The track system comprises a track-engaging assembly and a track disposed around the track-engaging assembly. The track system may be configured to have a reduced noise profile so as to generate less noise, enhanced track rigidity characteristics to improve its traction and floatation, and/or other features improving use and performance of the off-road vehicle.

Abstract: The present invention relates to a helical toothed belt including: a back portion; a tension member buried in the back portion; and a plurality of tooth portions arranged at a predetermined interval along a belt longitudinal direction on one surface of the back portion, in which the plurality of tooth portions have a tooth pitch of 1.5 mm or more and less than 2.0 mm, the back portion has a thickness of 0.4 mm or more and 1.2 mm or less, the tension member is formed of a twisted cord containing a high-strength glass fiber or a carbon fiber, and the ratio of the total value of an interval between the tension members adjacent to each other to the belt width is 20% or more and 60% or less.

Abstract: A long-stroke pumping unit includes a tower; a counterweight assembly movable along the tower; a crown mounted atop the tower; a sprocket supported by the crown and rotatable relative thereto; and a belt. The unit further includes a motor having a stator mounted to the crown and a rotor torsionally connected to the sprocket; and a sensor for detecting position of the counterweight assembly. The pumping unit may include a dynamic control system for controlling a speed of a motor.

Abstract: A long-stroke pumping unit includes a tower; a counterweight assembly movable along the tower; a crown mounted atop the tower; a sprocket supported by the crown and rotatable relative thereto; and a belt. The unit further includes a motor having a stator mounted to the crown and a rotor torsionally connected to the sprocket; and a sensor for detecting position of the counterweight assembly. The pumping unit may include a dynamic control system for controlling a speed of a motor.

Abstract: This disclosure is to provide an elastic crawler drive mechanism including an elastic crawler (20) with engaging portions (22) disposed on an endless belt (21), and a sprocket (10) having teeth (12), wherein: engaging surfaces (F2) of the engaging portions (22) have flat engaging planes (22b) in contact with a part of tooth surfaces (F1) of the sprocket (10) when in contact with tooth bottom surfaces (11a) of the sprocket (10), and when the engaging portions (22) are in contact with the tooth bottom surfaces (11a), and simultaneously the engaging planes (22b) are in contact with the tooth surfaces (F1) of the sprocket (10), at least one of the tooth surfaces (F1) of the sprocket (10) and the engaging planes (22b) of the engaging portions (22) form gaps (C) between the tooth surfaces (F1) and the engaging planes (22b), on sides closer to the tooth bottom surfaces (11a) than contact portions (P) of the tooth surfaces (F1) and the engaging planes (22b).

Abstract: A toothed belt has therein a core wire (3) including a core thread (1) made of aramid fiber and a filament thread (2) made of nylon fiber, and has belt tooth portions (4) and belt groove portions (5) alternately formed therealong. The core wire (3), the belt tooth portions (4), and the belt groove portions (5) are integrated with one another by a rubber material (7). It should be noted herein that the core thread (1) and the filament thread (2) are integrally twined around each other so that the filament thread (2) is formed in the shape of a plurality of loops around the core thread (1). The filament thread (2) in the shape of the loops enters tooth root portions (9) of the belt tooth portions (4) to be arranged therein. As a result, the tooth root portions (9) are strengthened.

Abstract: An elevator system includes a car or platform to transport passengers and/or goods as well as a counterweight, which are arranged as traversable or movable along a travel path, and which are coupled and/or with a drive by a suspension element interrelating their motion. The suspension element is guided and/or driven by a traction sheave and/or a drive shaft and/or a deflecting pulley. The suspension element is a sheathed and/or belt-type, with a first layer made of a first plasticizable and/or elastomeric material and a second layer with a connection plane formed between the first and second layers. At least one tension member—rope-type, tissue-type, or comprising a multitude of partial elements—is embedded in an area of the connection plane, a majority of a surface of said at least one tension member directly contacting said first layer. A manufacturing procedure for one of the suspension elements is provided.

Abstract: A toothed belt includes a body, at least one tooth formed of the body, a jacket disposed along a peripheral surface of the at least one tooth and having a compressed thickness in the range from 0.5 mm to about 0.8 mm, and at least one cord embedded in the body and having a diameter. The at least one cord and said jacket have a ratio of said cord diameter to said jacket thickness of less than 1.8, and said cord diameter and said jacket thickness describe an optical belt PLD of about 1.2 mm or less.

Abstract: A V-belt for high load transmission includes numbers of blocks engaged with and fixed to tension bands. Power is transmitted by meshing teeth of the blocks with grooves of the tension bands. A belt pitch width a being a width of each block at a position of a cord of each tension band, and a meshing thickness b of the tension band between bottoms of upper recesses and bottoms of lower recesses of the tension band satisfy a relationship of b/a?0.08. (That is, the meshing thickness b of each tension band is 8% or smaller of the belt pitch width a). The meshing thickness b of the tension band and a total thickness c of the tension band being a thickness of each of cogs, which are portions of the tension band other than the upper and lower recesses, satisfy a relationship of c/b?2.0.

Abstract: The durability of a belt is enhanced by improving the strength of rubber itself while enhancing its peeling strength with respect to a cord, a fabric or a short fiber. A toothed belt (10) comprises a belt body (13) that is integrally formed by a tooth rubber (11) provided on one surface side thereof, a backing rubber (12) provided on the other surface side, and an embedded cord (14) spirally wound in a boundary portion between the tooth rubber (11) and the backing rubber (12) that extends in the longitudinal direction of the belt. A facing fabric (20) covering the tooth rubber (11) is adhered to a surface of the tooth rubber (11), or one surface of the belt body (13). The tooth rubber (11) is obtained by vulcanization-molding a rubber composition including rubber such as HNBR, resorcinol, a melamine compound, silica and the like.

Abstract: The reinforcing cord of the present invention includes at least one strand. The strand includes a bundle of filaments that are bundled and twisted together in one direction, and a coating layer that is formed on at least the surface of the bundle. The bundle consists essentially of carbon fiber filaments. The coating layer is a coating layer that is formed from an aqueous treatment agent containing a rubber latex and a crosslinking agent as essential components and a filler as an optional component. In the aqueous treatment agent, the total of the mass of the crosslinking agent and the mass of the filler is in a range of 1 to 50% of the mass of rubber in the rubber latex.

Abstract: An energy harvesting system includes a heat engine and a component. The heat engine includes a belt, a first member, and a second member. The belt includes a strip of material and at least one wire at least partially embedded longitudinally in the strip of material. The wire includes a shape memory alloy material. A localized region of the at least one wire is configured to change crystallographic phase between martensite and austenite and either contract or expand longitudinally in response to exposure to a first temperature or a second temperature such that the strip of material corresponding to the localized region also contracts or expands. The first member is operatively connected to the belt and moves with the belt in response to the expansion or contraction of the belt. The component is operatively connected to the first member such that movement of the first member drives the component.

Abstract: A method of making a belt including the steps of: (a) helically wrapping a fabric strip of predetermined width on a mandrel at a first helix angle; (b) helically winding a tensile cord onto the mandrel over the fabric at a second helix angle less than the first helix angle; (c) wrapping a sheet or a strip of elastomer material around the mandrel over the tensile cord; and (d) curing the elastomer material under pressure to form a belt sleeve. The mandrel may be grooved for making toothed belts. The fabric strip may be preformed. A resulting toothed belt has a fabric seam spanning several teeth and having a helix angle. The seam may be joined.

Abstract: A looped material band (100) which includes at least one flat strip (2) having two reversible splice areas (3) in which the serrations (3a, 3b) only extend along a part of its width so that, when the material band is assembled in a loop around two pulleys (10a, 10b), the strands of the material band, which extend respectively between the two pulleys, are continuous and without any splice at least along a portion (9) of their width, regardless of the rotational position of the looped material band.

Abstract: The invention relates to an elastomeric composition comprising a branched polymer obtained from a polymer selected from the group consisting of NBR, HNBR, XHNBR, EP(D)M, and maleized EPDM and from a compound adapted to form a bond at a bond of the polymer to form a side chain. This compound comprises a group Y comprising a perfluoroalkyl functional group and a functional group adapted to react with the double bond. Preferably, Y=F(CF2CF2)m/wherein m is in the range between 2 and 20; R is selected from the group consisting of a double bond C?C, a triple bond C?C, a functional alcoholic, carboxylic, esteric, acrylic, methacrylic group. The invention also relates to the use of a composition as a body compound for a drive belt and to the use thereof in an oil bath.

Abstract: Described herein is a belt comprising a body made of elastomeric material, embedded in which is a plurality of longitudinal filiform resistant inserts, and a working surface covered with a covering fabric; advantageously the working surface is constituted by a toothing. The covering fabric is treated with a coating treatment. The coating treatment comprises a fluorinated elastomer. Advantageously, the coating treatment moreover comprises an antifriction agent and an elastomer formed by at least one copolymer obtained starting from a diene monomer and a monomer containing nitrile groups, more advantageously modified with a salt of an unsaturated carboxylic acid.

Abstract: A method of forming a power transmission belt including the steps of: providing a first layer made from rubber and having first and second oppositely facing sides; providing a mold; pressing the first side of the first layer conformingly against a surface on the mold having alternating projections and recesses to thereby form alternating teeth and troughs on the first layer; locally pressing the second side of the first layer at locations coinciding lengthwise with the teeth to thereby eliminate or prevent the formation of discrete holes; and joining the first layer, having the alternating teeth and troughs thereon, to at least one other component to define the power transmission belt.

Abstract: The invention relates to a drive belt (1), particularly a toothed belt, having an elastic base body, comprising a cover layer (2) as the belt back, and a subframe (4) having a power transmission zone (7), wherein the base body is made from oil-resistant vulcanized rubber on the basis of a copolymer comprising butadiene and acrylonitrile, particularly HNBR, wherein according to the invention the proportion of acrylonitrile (CAN proportion) is <33% by weight with regard to the total weight of the copolymer. The particularly advantageous CAN proportion is 20 to 35% by weight. The power transmission zone (7) is typically also equipped with a textile cover (8), which is further provided with an oil-resistant protective layer (9), which is preferably made from PTFE.

Abstract: A steel rope chain is provided for power transmission, including a plurality of parallel and juxtaposing closed steel ropes to which a plurality of equally-spaced wire rope clips is mounted. The wire rope clips are arranged in a juxtaposed manner and fixed to an elongate thick steel plate to form an array of clip assemblies that secure the steel ropes together. Mating the steel rope chain are a driving wheel and a driven wheel that are selectively made in various forms provided they include spokes having free ends carrying crossbars so that when the driving wheel rotates, the crossbars of the driving wheel are brought into engagement with the clip assemblies to drive movement of the steel rope chain and the steel rope chain in movement brings the clip assemblies into engagement with the crossbars of the driven wheel to cause rotation of the driven wheel.

Abstract: Noise and vibration of a helically-toothed-belt transmission device driven under heavy load or at a high-speed rotation, are reduced. A backlash “D” is selectively enlarged in a helically-toothed-belt transmission device that transmits drive force by meshing between a helically toothed belt and a helically toothed pulley. That is, a tooth helix angle “?” is set in a range of ?0.2?1?W·?/Pt?0.75, with “Pt” being a tooth pitch, “?” a tooth helix angle, and W the width of the belt. The backlash “D” between the helically toothed belt and the helically toothed pulley is set to be 1.6%-3% of the tooth pitch “Pt”.

Abstract: The present invention relates to drive assemblies, and particularly to drive belt and drive chain assemblies for operation of doors, gates or barriers. The invention provides a connection for a flexible toothed belt or similar, including a body having an internal recess with a shaping complementary to that of the toothed belt, configured to allow an end portion of the belt to be engaged therein in a direction transverse to the belt longitudinal direction, so to retain the belt against disengagement in the longitudinal direction.

Abstract: The timing belt and a coupling structure of the same are disclosed, in which a stress focused at a corner portion decreases by forming an optimum shaped groove at a corner portion of a timing belt, so that it is possible to largely increase a fatigue life span of a timing belt and a durability of a timing belt. In addition, noises and vibrations can be minimized by forming a through hole at a threaded surface of a timing belt or a threaded portion of a sprocket. In the timing belt, which has threads at a belt body, there is provided an improved timing belt comprising a groove formed at a corner portion in which the threads and the belt body contact with each other.

Abstract: A drive device (1) for machine auxiliary units (K, L, S/G) for transmitting a machine drive force from a machine (VM) to the machine auxiliary units by a belt. At least one machine auxiliary unit is provided as an electrical machine (S/G) that has either a poly-V-belt pulley to be driven by a poly-V-belt or a toothed belt pulley to be driven by a toothed belt. The belt has a toothed side (R1) and a poly-V side (R2) opposite one another, wherein a machine belt pulley is designed to drive the toothed side of the belt for transmitting the machine drive force, if the electrical machine has a poly-V-belt pulley, or is designed as a poly-V-belt pulley if the electrical machine has a toothed belt pulley.

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 includes the steps of: 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 a belt laminated body of similar structure in place of the removed dummy belt. Thus, abnormal shaped portions of the metal element can be efficiently and assuredly removed.

Abstract: A belt drive system and toothed idler sprocket having an arcuate pitch to significantly reduce noise. The toothed idler sprocket having a pitch sufficient to cause proper engagement between a belt and the sprocket at a minimal belt wrap angle.

Abstract: Disclosed is a belt tooth portion 11 of a toothed belt 8 incorporated in a toothed belt power transmission apparatus for use in equipment for business use. The belt tooth portion 11 comprises tooth root portions 12 formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline C2 in the tooth width direction, power transmission portions 13 formed of circularly arcuate surfaces of convex profile which contiguously adjoin the tooth root portions 12 and are arranged symmetrically with each other in respect to the tooth width direction centerline C2, tooth tip portions 14 formed of circularly arcuate surfaces which contiguously adjoin the power transmission portions 13 and are arranged symmetrically with each other in respect to the tooth width direction centerline C2, and a tooth crest surface 15 formed of an approximately flat surface which interconnects the tooth tip portions 14.

Abstract: A toothed belt includes a front rubber layer having teeth formed in the front rubber layer. A plurality of short fibers are entirely distributed in the front rubber layer. A first side of the front rubber layer is covered with a cover fabric. A back rubber layer contacts a second side of the front rubber layer. A plurality of cord elements extend along a length of the belt and are interposed between the front rubber layer and the back rubber layer in such a manner that a portion of each cord element is embedded in the front rubber layer, and the remaining portion of each cord element is embedded in the back rubber layer.

Abstract: A toothed belt with improved durability and low noise level during operation having a foundation fabric 2 adhesive-bonded along the engaging surface 5 thereof, wherein the yarns of said foundation fabric 2 extending in the longitudinal direction of the toothed belt comprise a plurality of false-twisted yarns false-twisted in the same false twist direction; the foundation fabric 2 is formed by weaving said yarns and the yarns crossing said yarns in a double-faced twill pattern and is located where the face of said foundation fabric 2 with fewer of said exposed false-twisted yarns is exposed to the front face.

Abstract: A toothed belt drive or chain drive has at least one toothed gear wheel and at least one toothed belt or chain. At least one tooth of the toothed gear wheel and/or at least one tooth of the toothed belt or at least one link of the chain has a flank geometry which is different from that of each of the other teeth.

Abstract: A continuously variable all speed transmission apparatus employs a conically-shaped driven surface which is frictionally contacted by a taut endless compliant transmission member that extends to a circular power source such as the pedal hub of a bicycle. The driven surface is centered upon an axis upon which an axle is disposed that causes rotation of a wheel such as a bicycle wheel. A shifting mechanism moves the contact site of the transmission member axially along the driven surface, thereby producing variation in the rotational speed of the wheel. The transmission member includes a central wire and a series of rollers disposed upon the wire in a manner to rotate about the wire without moving longitudinally thereupon.

Abstract: A drive assembly is constituted by a strip (10) and three or more parallel and rotatable supports (12, 16, 22) around which the strip (10) is wrapped. At least two of the rotatable supports (22) are linked together for common movement, for example by a movable holder in the form of a light box (20) carrying a series of light bulbs (50) while at least one of the rotatable supports (12, 16) is stationary.

Abstract: A tension member of a power transmission belt is formed of a braided cord composed of four aramid fiber strands having the same yarn number. The yarn number of the aramid fiber strands is 700 denier to 1300 denier. A ratio p/d of a braiding pitch p of the braided cord to a diameter d thereof is 3.7.ltoreq.p/d.ltoreq.5.5. Thereby increasing the flex fatigue resistance of the power transmission belt.

Abstract: A combination of a sprocket wheel and a rapier band employed in a rapier loom is improved for extending the service life of the rapier band. Each of the female holes formed in the rapier band for receiving teeth of the sprocket wheel is formed in a frustum-like shape. The teeth of the sprocket wheel have tooth surfaces each including a non-interference portion located above an expansion/contraction-insusceptible layer of the rapier band and an interference portion located underneath the expansion/contraction-insusceptible layer. The non-interference portions do not contact the tooth surfaces, while the interference portions are brought into contact with the wall surfaces of the hole formed in the rapier band when the band is wrapped around the sprocket wheel.

Abstract: A toothed belt is provided with at least one end attachment part for connecting an end portion of a toothed belt to a housing part or a component to be driven. The end attachment part is a formed strip made of metal or plastic in order to make the attachment of the toothed belt quicker and simpler. The strip has elements or sections which engage in the teeth of the end portion and are securely held therein. In the assembled condition, the end attachment part includes a portion to facilitate a mechanical connection at its end facing away from the end portion of the toothed belt.

Abstract: A synchronous drive belt has at least two adjacent rows of teeth which are at oppositely balanced oblique angles to the longitudinal direction of the belt. In addition, the centerlines of the teeth in the adjacent rows are offset from each other by a distance of up to 10% to 90% of their pitch.

Abstract: A roller belt arrangement for caterpillar track-type vehicles and having several rotating belts that are connected via grippers that guarantee a positive drive and are secured to the belts via screw bolts. To prevent lateral bulging of the belt from occurring during securement of the grippers, which bulges lead to undesired shearing stresses in the belt body, in the vicinity of lateral edges of the gripper and/or their securement elements, the rubber cover layers are provided with notches that extend along the edges and prevent or reduce the stresses in the belt body caused by the bulging.

Abstract: A device is for connecting the ends of a toothed belt having a plurality of longitudinal reinforcing cords. The device includes a connecting element having at least two interconnected lock parts. Each of the interconnected lock parts has a plurality of holes for respectively receiving an end of one of the reinforcing cords therein. Each of the ends of the reinforcing cords is connected with the lock parts by being force-locked within the hole.

Abstract: In a toothed belt, each tooth of the belt in longitudinal cross-section has a tooth top part composed of a pair of tooth top portions and a tooth tip portions formed in circular arcs, respectively, whose radius dimensions and location of centers are predetermined by a set of equations and inequalities so that a first contact point of the belt tooth with a pulley groove approaches to a tooth center line. In a power transmission device using the abovedescribed toothed belt and a toothed pulley, a shape of each pulley groove of the pulley is predetermined by a set of equations and inequalities so that a compressive force applied to the belt tooth during engagement concentrates to the tooth center line.

Abstract: A flexible link belt has a flexible belt woven of weft and warp threads or filaments leaving interstices between the filaments. Links, such as snap buttons or gear teeth of synthetic material, have one portion on each side of the flexible belt. The link portions are secured to each other directly through the interstices by melting the link portions to each other through the interstices by injection molding.

Abstract: A wire processing system wherein lengths of insulated wire are sequentially presented to processing stations for insulation stripping and subsequent terminal crimping, is disclosed employing an improved wire gripping and transporting arrangement having a flexible conveyor belt with a plurality of wire keepers molded to and distributed about the belt, each keeper including a pair of upstanding resilient projections having a gap therebetween to receive and grip a section of wire, an input station where wire is pushed into the gap between projection pairs, and an output station including a picker to be positioned adjacent the projection pair between the wire and the belt with relative motion between the picker and the keeper ejecting the wire from the gap. The belt is entrained on a drive wheel having a plurality of generally flat peripheral surfaces, and on an idler wheel.

Abstract: A toothed belt that has a tensile member of spirally wound cord where the operating pitch line of the belt is at least partially established by the cord which is made by twisting together at least two substantially zero twist, unequal denier yarn ends to form a ply, and twisting at least two of such piles together in the opposite direction to form the cord.

Abstract: A belt for transmitting motion between two pulleys comprising an annular body of elastomeric material, at least a plurality of openings aligned in the longitudinal direction of the belt for engaging with corresponding protuberances on the pulleys, continuous elongated elements resistant to traction and directed in the longitudinal direction of the belt, and reinforcing elements directed along two directions, symmetrically inclined to each other with respect to the longitudinal direction of the belt.

Abstract: A continuous driving belt, adapted for transmitting movement between two elements, each one of which is rotatable around an axis and which is provided with pins projecting in the radial direction with respect to said axis, which are adapted for insertion into corresponding holes made in the belt itself. Said belt is constructed with a primary, deformable polymeric material having a Shore-A hardness greater than 75 degrees, and is provided with a reinforcing structure that comprises a plurality of annular elements which are embedded in said primary material and which are constructed out of a secondary material that presents an elongation substantially less than that of said primary material. The annular elements lie on planes that are substantially parallel to the longitudinal plane of the mid-plane of the belt itself.

Abstract: Herein disclosed is a V-belt transmission device in which a plurality of substantially V-shaped metal members (2) and a plurality of resilient metal members (3) are alternately mounted to an endless metal belt member made of band steel and are in contact with each other to constitute a V-belt which is subjected to a tension between a driving V-pulley (5) and a driven V-pulley (6), thereby effecting a torque transmission between both the pulleys. Each of the V-shaped metal members (2) is provided with a substantially U-shaped groove (7) directed to the outside. Each of the resilient metal members is formed as a hollow roller to engage with recessed surfaces (8) which are formed in opposing surfaces of a pair of the V-shaped metal members (2). The V-shaped metal members (2) and the resilient metal members are fastened together at their outer peripheries by the metal belt member.

Abstract: An interlocking driving belt wrapped around a toothed driving wheel and a toothed driven wheel to transmit power from the former wheel to the latter wheel, comprising a plurality of toothed blocks having tooth-shaped portions capable of being meshed with tooth spaces on outer circumferential surfaces of both of the wheels, a plurality of rollers held rotatably among the toothed blocks, a flat endless belt member wrapped tightly around outer circumferential surfaces of the rollers, stopper plates fixed to the toothed blocks, each of which stopper plates contacts one of two adjacent toothed blocks to retain these two toothed blocks in predetermined positions, and roller-receiving recesses provided in both of side surfaces of the toothed blocks to hold adjacent rollers therein. This interlocking belt can be made in small dimensions and weight at a low cost and can be suitably used to transmit high torque at a high speed under both the dry and wet conditions.

Abstract: Belt for transmitting motion between two pulleys comprising a flat-shaped annular body of elastomeric material, reinforced with continuous and flexible elongated elements, resistant to traction and arranged in the longitudinal direction of the belt, a plurality of openings in the belt to engage with protuberances on the pulleys, at least one continuous reinforcing element disposed around the opening with ends anchored to the longitudinal elements.

Abstract: A drive belt (10) having an elongated body (11) provided with tensile cords (12). The belt is provided with teeth, or cogs, (13) and a two-ply reinforcement is provided on the surface of the teeth, or cogs, including an inner layer (15) and an outer layer (17). The inner layer is formed of parallel yarn, or twine, elements (16), which may be spirally wrapped to extend in the longitudinal direction of the belt. The outer layer is formed of a woven or knit cloth, and in the illustrated embodiment, is formed of a sailcloth having a highly elastic warp extending in the longitudinal direction of the belt and an inelastic weft for providing improved transverse rigidity and strength. The first layer yarn (16) and second layer warp (19) preferably have a ductility of greater than 50%. A number of candidate materials for the high ductility yarns is disclosed.

Abstract: A flexible power transmission belt having a plurality of teeth each of which has a pair of arcuate convex flank portions which in longitudinal cross-section closely approximate to an arc of a circle. Each tooth exhibits a height to width relationship within a predetermined range, and the arcuate flanks each have a pressure angle within a predetermined range. The belt is preferably used in combination with a toothed pulley whose teeth are substantially conjugate to the belt teeth and whose cavities between the teeth have a height to width relationship within another predetermined range and have concave flanks exhibiting a pressure angle in still another predetermined range, said belt tooth width being approximately 0.98 of the pulley cavity width so as to provide a high torque positive drive power transmission system having minimum backlash.

Abstract: A power transmission belt having a plurality of teeth of elastomeric material positioned along a peripheral surface of said belt, each possessing a predetermined spring rate, and a fabric cover formed over the teeth and over the land portions between the teeth, said fabric cover cooperating with said teeth such that the spring rate of each fabric covered tooth is greater than 1.2 times and less than 3 times the spring rate of such tooth alone.