Abstract: A transmission belt is described which comprises a body made of a first elastomeric material, a plurality of teeth and a plurality of longitudinal cords buried in the body of the belt and a back. The belt has a working surface on said teeth and the working surface is at least partially covered by a covering made of a plastic and/or metal material. Defining the area comprised between the plane defined by the neutral axis of the cords, the working surface and the median transverse planes of two adjacent teeth as the unitary longitudinal section, the covering preferably occupies at least 25% of the unitary longitudinal section.

Abstract: The hybrid tape includes an outer member that is formed with a material having desirable tensile qualities, such that the outer member is tailored to exhibit superior fatigue performance in tension induced from bending. The hybrid tape further includes an inner member that is formed with a material having desirable compression qualities, such that the inner member is tailored to exhibit superior fatigue performance in compression induced from bending. The hybrid tape is configured such that the bend neutral axis is located between the inner material and the outer material, thereby insuring the outer material only experiences tension in bending while the inner material only experiences compression in bending.

Abstract: A drive belt having a belt body which is made of a flexible material and a tensile reinforcement that extends in belt axial direction and which is surrounded by said belt body in sections at least to improve the tensile strength of the body in belt longitudinal direction wherein the tensile reinforcement is a carbon cord made of a plurality of twisted carbon fibers with a plurality of cavities between the fibers which are charged with a filler material in part at least. A first portion of the carbon fiber cavities is charged with a rupture risk reducing filler of a type different from the belt body flexible material and a second portion of said cavities of the carbon fibers is filled with belt body flexible material. The carbon cord has less than 0.2 mg of belt body flexible material per one millimeter3 cord volume.

Abstract: A flat belt (2), which is made of elastomeric material (46a, 46b), is made up of a first partial belt (2a) and a second partial belt (2b). The first partial belt (2a) is reinforced with a reinforcement layer (4) made up of cords. A layer separation which is to be feared theoretically is to be reliably avoided and the bonding of the belt material to the reinforcement layer (4) is to be optimized. The first belt part (2a) is provided with slots (44) with the aid of mold drum winding-projections (42); the second belt part (2b) defines a filling of the slots (44) of the first belt part (2a). Preferably, the reinforcement layer (4) is positioned centrally in the neutral bending plane of the finished flat belt (2). The first belt part (2a) and the second belt part (2b) can be made of different elastomeric materials (46a, 46b). Also, at least one of the two surfaces of the belt (2) can be coated and/or provided with a longitudinal profile or transverse profile.

Abstract: A fabric for reinforcing a power transmission belt including fibers of polyarylene sulfide and a belt utilizing the fabric. The fabric may have textured or elastic core wrapped stretch yarns in the longitudinal direction. Longitudinal yarns may include PPS and textured transverse yarns include nylon. Yarns may include blends of high performance fibers and nylon or other fibers.

Abstract: A power transmission belt has a compression section, a tension section, and a load carrying section. The load carrying section has a plurality of reinforcing cords. The reinforcing cords are formed from poly(p-phenylene-2,6-benzobisoxazole) (PBO). In each reinforcing cord, the cords have a yarn twist greater than the cord twist, and the cord twist is in the range of one-forth to one-half of a ply twist.

Abstract: A power transmission belt. The power transmission belt includes the following: a backing layer; a body having a top surface and a bottom surface, the bottom surface joined with the backing layer, the top surface including a plurality of teeth, and the body including a plurality of reinforcing cords positioned between the top and bottom surfaces; and a fabric material having a top surface and a bottom surface, the bottom surface at least partially embedded in the top surface of the body, the fabric material being a weft knitted structure having N×N ribs, wherein N is at least 2, and the top surface of the fabric material being at least partially exposed at surfaces of the plurality of teeth.

Abstract: [Problems] To provide an endless belt for power transmission capable of efficiently improving the yawing attitude of the elements in a variable pulley. [Means for Solving the Problems] This endless belt (40) for power transmission includes the elements (42) and an annular band-like member (46) for supporting the elements (42). The endless belt is winched between a pair of variable pulleys (20, 30). Groove parts (60) extending from the front surface of the belt in the forward movement direction to a predetermined position not reaching to the rear surface of the belt in the forward movement direction are formed in the side surfaces (42A) of the elements (42) contacting with the belt sliding surfaces (26, 36) of the variable pulleys (20, 30).

Abstract: A power transmission belt. The power transmission belt includes the following: a backing layer; a body having a top surface and a bottom surface, the bottom surface joined with the backing layer, the top surface including a plurality of teeth, and the body including a plurality of reinforcing cords positioned between the top and bottom surfaces; and a fabric material having a top surface and a bottom surface, the bottom surface at least partially embedded in the top surface of the body, the fabric material being a weft knitted structure having N×N ribs, wherein N is at least 2, and the top surface of the fabric material being at least partially exposed at surfaces of the plurality of teeth.

Abstract: A method of making a power transmission belt/belt sleeve having a body with a continuous length extending around an axis, an inside, an outside spaced radially from the inside, and at least one of a) a plurality of ribs extending lengthwise and b) a plurality of cog teeth spaced at lengthwise intervals, on one of the inside and outside of the belt/belt sleeve.

Abstract: A multi-ribbed power transmission belt has transverse grooves in the compression section which are oriented at angles other than perpendicular. The combination of longitudinal grooves and transverse grooves form a plurality of cogs on the belt surface, with a row of cogs being defined between adjacent transverse grooves. Each cog has a pitch length P extending from a location on the cog to the identical location on the longitudinally adjacent cog. The pitch lengths of the rows of cogs are randomized over the entire length of the belt to reduce the noise of the belt as it travels about its associated pulleys.

Abstract: A toothed transmission belt comprises a metal core including two mutually parallel and spaced apart metal strips, substantially coplanar to each other, and a plurality of metal cross-members, distributed according to a constant pitch in the longitudinal direction of the belt, which connect the two metal strips to each other.

Abstract: A power transmission belt having an endless body with a length, an inside, and an outside. The body has cogs on at least one of the inside and outside of the body and spaced along the length of the body so as to define alternating cog crests and cog troughs. The cog crests each have oppositely facing side surfaces with an apex between the oppositely facing side surfaces. There is a reinforcing fabric on the at least one of the inside and outside of the body. The reinforcing fabric has first and second spaced end portions with a first free end at the first end portion and a second free end at the second end portion. The first and second end portions overlap so that the first and second free ends are each at a side surface on a cog crest.

Abstract: A power transmission belt having an endless body with a length, an inside, and an outside. The body has cogs on at least one of the inside and outside of the body and spaced along the length of the body so as to define alternating cog crests and cog troughs. The cog crests each have oppositely facing side surfaces with an apex between the oppositely facing side surfaces. There is a reinforcing fabric on the at least one of the inside and outside of the body. The reinforcing fabric has first and second spaced end portions with a first free end at the first end portion and a second free end at the second end portion. The first and second end portions overlap so that the first and second free ends are each at a side surface on a cog crest.

Abstract: A toothed belt transmission is provided in which a toothed belt is trained around drive and driven pulleys. Each toothed pulley has a circumferential periphery formed with a plurality of teeth. Adjacent teeth are assigned as a first tooth portion and a second tooth portion. Respective tooth portions have arcuate portions at corners defined between tooth edges and tooth surfaces. A line touching the arcuate portions of the first and second tooth portions is assigned as a common tangential line. A line passing over a starting point of the arcuate portion of the tooth edge of the first tooth is assigned as a first tangential line. An angle between the common tangential line and the first tangential line falls in a range between 6° and 14.4°.

Abstract: A linear drive includes a toothed belt (2) driven by direction-changing rollers (1) in the pretensioned state. The toothed belt (2) has at least one tension reinforcement. The teeth (3) of the belt (2) engage in the teeth gaps (4) of a linear toothed counterpiece (5) over a specific length. The pitch of the teeth (3) of the belt is slightly less up to 0.8% than the pitch of the toothed counterpiece (5) in the pretensioned state of the toothed belt (2) and during loading of the toothed belt which occurs during operation under load. The tooth flank (6) of the tooth (3) of the belt is at right angles or almost at right angles to the plane of the tension reinforcement (7) and the tooth gap (4) of the toothed counterpiece (5) is approximately 20% to 80% wider than the width of the tooth (3) of the belt. The belt teeth (3) are elastically configured compared to the high stiffness of the tension reinforcement (7).

Abstract: A continuously-variable-ratio transmission belt includes a beltlike continuity element having a body made of elastomeric material and in turn having inner teeth and outer teeth and a number of threadlike longitudinal inserts embedded inside the body; and a number of separate friction blocks which are made of plastic material, are co-molded onto the continuity element so as to each incorporate one tooth of the inner teeth and one tooth of the outer teeth, and are each defined by two lateral surfaces converging inwards of the belt and cooperating with respective sides of a groove of a trapezoidal-grooved pulley.

Abstract: A toothed belt power transmission system includes a toothed belt having evenly spaced teeth adapted to mesh with evenly spaced teeth on a toothed pulley for power transmission. The belt teeth have a curved engagement surface including a convexly arcuate tip portion and a concavely arcuate root portion that come in sliding contact with a concavely arcuate root portion and a convexly arcuate tip portion, respectively, of a curved engagement surface of the pulley teeth in such a manner that a space is defined between the confronting engagement surfaces of the belt and pulley teeth. By virtue of the space thus formed, air confined between the belt tooth and pulley tooth is allowed to escape in the transverse direction of the belt and does never produce bursting sound at the mesh of the belt tooth with the pulley tooth. In this instance, the air serves also as a pneumatic damper and thus suppresses the impact force.

Abstract: A method of producing synchronous belts having two or more tracks of teeth extending obliquely from the belt. The method includes forming an internal drum mold from a series of concentric rings, building a belt sleeve around the drum mold, vulcanizing the belt assembly, cutting the belt sleeve into widths and removing drum rings from the belt sections.

Abstract: An endless belt (10) for use in exercising treadmills is provided. The endless belt includes at least an underlying ply (18) of low friction material, an internal core (38) of compressive and resilient material, and an overlying skin (42) of abrasion resistant material. The internal core (38) consists of a series of transverse projections (30) having inclined side walls (46, 47). The shape of projections (30) of the internal core (38) allows for the compression thereof while providing a suitable walking/running surface. The underlying ply (18) minimizes friction between the belt and any underlying support. The overlying skin (12) increases the durability of the belt while providing friction between a user's foot and the belt (10) for movement thereof. The belt may further include a reinforcing ply (32) disposed between the underlying ply (18) and the internal core (38).

Abstract: Toothed belt in which the toothed part is covered with a fabric consisting of a warp and a weft consisting of weft threads formed by an elastic thread, preferably made from polyurethane, acting as the core, and by at least a pair of composite threads wound on the elastic thread. Each composite thread comprises a thread with high heat resistance and high strength, preferably made from para-aromatic polyamide, and a covering thread, preferably made from nylon, wound on the thread with high heat resistance and high strength. The structure of the weft of the toothed belt is such that each thread with high heat resistance and high strength can be completely isolated in such a way that it is not damaged by the friction of the belt against the teeth of the pulley, ensuring a greater durability of the belt. The structure with a pair of composite threads also makes it possible to increase the breaking load of the fabric.

Abstract: An apparatus and method for manufacturing a synchronous drive belt or timing belt is disclosed. The method allows a belt with axially interlocked teeth to be manufactured. The method utilizes transfer molding, as opposed to compression molding, and involves an inflatable diaphragm which pushes rubber radially outwardly from a mandrel into a mold having teeth on an inner surface. The method includes the provision of a barrier layer which can be advantageously built into the belt to improve the transfer molding process.

Abstract: A magnetic tape cartridge incorporating a drive belt characterized by a pattern of recesses in the belt surface in contact with the magnetic tape which are used to provide traps for tape contaminants. Different types of patterns are used to eliminate tension variations which would otherwise occur as a consequence of tape contaminants during the projected life of the cartridge.

Abstract: A synchronous belt of the present invention has a tension member in the form of a cord, a plurality of teeth fixedly provided on one side of the tension member at set intervals in a longitudinal direction of the belt and a back layer bonded to the other side of the tension member. The back layer and the teeth are formed of urethane elastomer. The tension member is formed of inorganic fibers and is impregnated with a water based latex adhesive. A film of an epoxy adhesive is formed on the surface of the tension member.

Abstract: A power transmission belt with a body of belt material and belt teeth formed of the body and covered with a knitted fabric with a 1.times.1 rib construction.

Abstract: An endless flexible seamed belt with a mechanically invisible seam and substantially equivalent in performance to a seamless belt is formed by joining two ends of material from which the belt is fabricated each end of which has a plurality of mutually mating elements in a puzzle cut pattern which are in interlocking relationship in at least one plane and which when joined mechanically enable the flexible belt to essentially function as an endless belt having a substantially uniform thickness.

Abstract: An endless elastomeric belt includes a plurality of longitudinally separated guide blocks each having a longitudinally extending slot in a tip portion thereof. The slot reduces the mass of the guide block at a location most effective for reducing acceleration forces generated in the belt at a position where the belt separates from the entrained wheels at high rotational speeds. Reducing the acceleration forces reduces fatigue failures tending to occur in the bond joint between the guide block and a belt body.

Abstract: The combination of an endless power transmission belt construction and pulley therefor, the belt construction and methods of making the same are provided, the belt construction having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart like longitudinal projections and longitudinal grooves that are adapted to mesh with a ribbed surface of a pulley, the inner surface of the belt construction being cogged and defining a plurality of transversely disposed and alternately spaced apart transverse projections and transverse grooves, the transverse grooves each having a depth that is approximately one-half of the depth of the longitudinal grooves and that is approximately one-fourth of the thickness of the belt construction.

Abstract: An endless elastomeric vacuum sweeper belt for use in a vacuum sweeper having a diamond pattern drive surface. A first set of ribs project inwardly in a substantially diagonal direction along the drive surface of the belt. A second set of ribs project inwardly along the drive surface of the belt in a substantially diagonal direction opposite the direction of the first set of ribs. The first and set second set of ribs together define a diamond-like pattern on the drive surface as well as a number of particle recesses for the temporary collection of matter. Each rib includes knife-like edge portions to increase the traction of the belt on a drive surface by cutting, loosening and expelling foreign matter lodged between the belt drive surface and the rotation member and/or the drive source of the vacuum sweeper.

Abstract: A toothed belt of the present invention comprises a back surface section and tooth sections that are made of an acrylonitrile-butadiene copolymer (NBR) with a hydrogenation rate of 90% or more; a tooth cloth that covers the surface of the tooth sections and tooth lands, the tooth cloth being made of an industrial nylon raw fiber with a viscosity relative to sulfuric acid of 2.45 to 2.53, a tensile strength of 5 g/denier or more, and a fineness of single fibers of 5 denier or less and being treated with resorcinol-formaldehyde-latex (RFL) liquid in which resorcinol-formaldehyde resin is mixed with a hydrogenated NBR as a latex component; and core fibers with a core diameter of 0.63 to 0.85 mm, the core fibers being made of twisted bundles of glass fibers of high strength.

Abstract: An endless belt comprising a belt main body prepared from a liquid castable elastomeric material, a reinforcing fabric providing over the surface of the main body, and a shock absorbing layer of elastomeric material formed between the main body and the fabric. The belt is in the form of a flat belt or a belt having teeth or projections on at least one side thereof, has improved bending resistance and is operable with diminished noise. The belt is prepareed by a process comprising the steps of forming a shock absorbing layer of elastomeric material over the surface of a reinforcing fabric, fitting the fabric to one of an inner die and an outer die with the layer facing the other die, and pouring or injecting a liquid castable elastomeric material into a space between the fabric and the other die for molding.

Abstract: An endless power transmission belt construction and method of making the same are provided, the belt construction having opposed side edges and having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart projections and grooves for meshing with a ribbed surface of a rotatable pulley or the like and defining a plurality of transversely disposed and alternately spaced apart projections and grooves that respectively extend between and to the opposed side edges, the longitudinal spacings between the transverse grooves or/and the depths of the transverse grooves being staggered so as to tend to reduce noise during normal operation of the belt construction with the pulley or the like.

Abstract: An adjustable torque transmitting belt comprising a plurlity of links. The links are attached end to end forming a belt of any desired length. The ends of the belt formed by the plurality of links are attached together by combining three different specialized links with a flexible bolt. The flexible bolt fits through a bore in a male link attached to one end of the belt, then through a bore in a rotator link, then treaded into a female link attached to the other end of the belt. A continuous loop belt is then formed that can be easily adjusted by the specialized link and flexible bolt assembly. A single flexible elongated link may be utilized in lieu of a plurality of smaller links. In another embodiment a plurality of identical links are assembled together to form an adjustable continuous belt. Each link can be securely attached without the use of tools due to the flexible nature of the configuration and the material of the similar links.

Abstract: An endless power transmission belt construction and method of making the same are provided, the belt construction having opposed side edges and having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart projections and grooves for meshing with a ribbed surface of a rotatable pulley or the like and defining a plurality of transversely disposed and alternately spaced apart projections and grooves that respectively extend between and to the opposed side edges, the longitudinal spacings between the transverse grooves or/and the depths of the transverse grooves being staggered so as to tend to reduce noise during normal operation of the belt construction with the pulley or the like.

Abstract: An endless power transmission belt construction, a rotatable pulley therefor, a combination of the belt construction and pulley and methods of making the same are provided, the belt construction having opposed side edges and having an inner surface defining a plurality of longitudinally disposed and alterntely spaced apart like projections and grooves for meshing with an outer peripheral ribbed surface of a rotatable pulley, each projection of the belt construction having a generally V-shaped transverse cross-sectional configuration defined by two substantially straight side edges that converge from the respective apexes of the grooves of the belt construction that are on opposite sides of that projection to an apex of that projection, the side edges of each projection of the belt construction defining an angle of approximatly 60.degree. therebetween with the thickness of the belt construction being substantially the same as the thickness of a similar belt construction wherein the angle is approximately 40.

Abstract: An endless power transmission belt construction and method of making the same are provided, the belt construction having opposed side edges and having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart projections and grooves for meshing with a ribbed surface of a rotatable pulley or the like and defining a plurality of transversely disposed and alternately spaced apart projections and grooves that respectively extend between and to the opposed side edges, the longitudinal spacings between the transverse grooves or/and the depths of the transverse grooves being staggered so as to tend to reduce noise during normal operation of the belt construction with the pulley or the like.

Abstract: A belt formed of elastomeric material is provided for transmission of forces in cooperation with at least two pulleys. The belt is formed by an outer part under traction, an inner part under compression and an intermediate part interposed between the inner and outer parts. The inner part includes at least two lateral, opposite and convergent surfaces suitable for transmitting frictional forces with the corresponding surfaces of the pulleys. The belt includes a plurality of transversely directed alternating protuerances and cavities in the inner part. The sequence of transversal cavities and protuberances define an undulated profile. The ratio between the pitch (p) and the depth (h) of the transversal cavities is between 8 and 20, and the ratio between the radius of curvature (r) of the transversal cavities and the depth (h) of the cavities is between 3 and 6.

Abstract: An endless power transmission belt construction and method of making the same are provided, the belt construction having opposed side edges and having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart projections and grooves for meshing with a ribbed surface of a rotatable pulley or the like and defining a plurality of transversely disposed and alternately spaced apart projections and grooves that respectivley extend between and to the opposed side edges, the longitudinal spacings between the transverse grooves or/and the depths of the transverse grooves being staggered so as to tend to reduce noise during normal operation of the belt constructuion with the pulley or the like.

Abstract: A toothed power transmission belt having a high modulus polyurethane body, an aramid type -II tensile member occupying up to about 88 percent of the belt width, and a wear-resistant fabric disposed along the belt inner surface at the tooth flanks.

Abstract: An endless power transmission belt construction and method of making the same are provided, the belt construction having opposed side edges and having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart projections and grooves for meshing with a ribbed surface of a rotatable pulley or the like and defining a plurality of transversely disposed and alternately spaced apart projections and grooves that respectively extend between and to the opposed side edges, the longitudinal spacings between the transverse grooves or/and the depths of the transverse grooves being staggered so as to tend to reduce noise during normal operation of the belt construction with the pulley or the like.

Abstract: The combination of a toothed pulley and a toothed belt and method of making the same are provided. The toothed belt has teeth that serially mesh with cavities of the pulley that are respectively disposed between adjacent teeth thereof. Each pulley cavity has a longitudinal substantially trapezoidal cross-sectional configuration. Each belt tooth has a longitudinal cross-sectional configuration that defines a pair of spaced side faces that respectively has free end portions that are remote from adjacent roots thereof and that are spaced apart from each other by a bottom face of the tooth.

Abstract: The combination of a toothed pulley and a toothed belt and method of making the same are provided. The toothed belt has teeth that serially mesh with cavities of the pulley that are respectively disposed between adjacent teeth thereof and that respectively have bottoms. Each belt tooth has a longitudinal cross-sectional configuration that defines a pair of spaced side faces that respectively have free end portions that are remote from adjacent roots thereof and that are spaced apart from each other by a bottom face of the tooth, each bottom face having a center.

Abstract: A V belt to be used for a dry type transmission. It comprises two endless load carriers and a plurality of blocks in engagement with said load carriers relatively immovable in lengthwise direction of the belt. Said load carrier has elastomers and tensile members embedded in said elastomers. Said block is made of plastics or hard rubber and has slant side surfaces to fit substantially to the groove surface of a pulley on which the V belt is wound and a slot which extends from said slant side surface toward the central part of the block and in which the load carrier is fitted.

Abstract: An endless power transmission belt construction and method of making the same are provided, the belt construction comprising an outer tension section, an inner compression section and a load-carrying section secured to and disposed intermediate the tension section and the compression section, the compression section having an inner surface defining a plurality of longitudinally disposed and alternately spaced apart projections and grooves and a plurality of transversely disposed and alternately spaced apart projections and grooves. Each transverse groove has a depth between approximately 0.070 of an inch and approximately 0.080 of an inch and is spaced from the next adjacent transverse groove thereto by a distance between approximately 0.3 of an inch and approximately 0.4 of an inch while each longitudinal groove has a depth of approximately 0.095 of an inch and is spaced from the next adjacent longitudinal groove thereto by a distance of approximately 0.140 of an inch.

Abstract: A belt construction and method of making the same are provided, the belt construction having opposed sides and comprising a tensile unit intermediate the opposed sides, a plurality of teeth defining one of the opposed sides of the belt construction and being mainly formed of a first polymeric material that has reinforcing fibers therein, each tooth having opposed sides that are disposed in spaced relation to adjacent sides of adjacent teeth, the belt construction having a land area between adjacent teeth, and a backing member defining the other of the opposed sides of the belt construction, the backing member being mainly formed from a second polymeric material that is initially separate from the material of the teeth.

Abstract: A belt construction and method of making the same are provided, the belt construction having opposed sides and comprising a plurality of teeth defining one of the opposed sides of the belt construction and being mainly formed of a first polymeric material that has reinforcing fibers therein, each tooth having opposed sides that are disposed in spaced relation to adjacent sides of adjacent teeth, the belt construction having a land area between adjacent teeth, and a backing member defining the other of the opposed sides of the belt construction, the backing member being mainly formed from a second polymeric material that is initially separate from the material of the teeth.

Abstract: A reinforced elastomeric drive belt 20 having tooth-like protuberances 21 for meshing with the teeth of a pulley is provided with reinforcing fibers 27 distributed through at least a portion of each tooth 21.Also provided is a method for building the improved belt and an improved apparatus for building such a belt.

Abstract: A V-belt construction (10) utilizing one or more layers (19) of transverse cord fabrics in the compression section (17) thereof. The fabric cord layers are embedded in cushion rubber provided with short transverse reinforcing fibers and are laid down in a serpentine manner so as to follow the valleys and peaks of the cog portions (16) of the belt, with the layers being spaced apart in the peak portions (22) of the cogs and closely juxtaposed in the valley portions (21) thereof.

Abstract: A V-section cog belt having a rubber body provided with longitudinally spaced inner cogs defining an inner surface. The belt is provided with conventional tensile cords extending longitudinally thereof. Rigid metal reinforcement members are provided in the cogs extending transversely across the belt in outwardly spaced relationship to the inner surface thereof. The reinforcement members may have any one of a plurality of different configurations, including tubular configurations and solid cross section configurations. The outer and inner surfaces of the tubular configurations may be similar or different as desired. In one form, the reinforcement members are spring plates. The reinforcement members may be provided as single members in each of the cogs or a plurality of members in the cogs as desired.

Abstract: A power drive system including a toothed belt (10) arranged for improved engagement with a grooved pulley (15). The belt teeth (13) define, in longitudinal cross section, planar flank surfaces (22, 23) and an intermediate arcuate tip surface (25). The pulley groove (14) has corresponding planar flank surfaces (17, 18). The arcuate distal portion of the belt tooth is disposed within an arcuate segment centered on the point of intersection (19) of a flank surface (17) of the belt pitch line (20) defined by the tensile members (12) of the belt body portion. The tooth tip portion (25) defines a circular cross section centered on a point (37) disposed within a preselected range on the tooth centerline (24).