Abstract: An adjustless V-belt and method of manufacture. The V-belt comprises: a compressive rubber layer made of a heatproof or coldproof rubber and an adhesion rubber layer laminated on said compressive rubber layer. A group of cogs protrude from said adhesion rubber layer with a predetermined pitch and depth and a longitudinally stretchable cover canvas covers the cogs, and the roots between said cogs. Rope tensile members are embedded between the adhesion rubber layer and the group of cogs with a regular pitch line and in the cylindrical state such a manner that parts of the tensile members are in contact with said cover canvas. The rope tensile members have a high thermal contraction stress of at least 3.5 g/denier which is the differential between a thermal contraction stress at 100.degree. C. and that at room temperature (about 20.degree. C.). Short fibers are embedded in the compressive rubber layer in such a manner that the short fibers are orientated laterally therein.

Abstract: An endless power transmission belt having a plurality of grooves which are formed in the inner surface of the belt in such a manner that the grooves extend perpendicular to the longitudinal axis of the belt, and a plurality of cogs each of which is formed between adjacent grooves thereof. At least two of three factors, groove pitch in the longitudinal direction of said belt, grooves depth and groove cut angle are changed at random. In one example, the groove pitch is changed at random in a range of 60% to 100% of the thickness of said belt, groove depth is changed at random in a range of 20% to 40% of the thickness of the belt, and the groove cut angle is changed at random in a range of 10.degree. to 40.degree..

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 pulley configuration which increases the contact area between the pulley tooth tips and the land area of the belt teeth. The increased contact area reduces land area wear between belt teeth. The pulley tooth tip has a longitudinal cross-sectional contour partially composed of two substantially circular arcs connected by a line segment which is substantially straight or slightly curved. The length of the line segment is from 2 percent to 100 percent of the width of the belt tooth on which the pulley is used, and preferably less than about 7 percent of the width of the belt tooth. The pulley groove depth may be less than the height of the belt tooth and the groove has a longitudinal cross-sectional contour partially composed of two substantially circular arcs connected by a line segment which is substantially straight or slightly curved. The pulley in combination with a toothed belt forms a positive power transmission system.

Abstract: A belt for transmitting power from a cogged driving member to a cogged driven member such as a pair of wheel sprockets. The belt has inflexible teeth spaced along the direction of its travel. Each of the teeth have a longitudinal axis transverse to the direction of belt travel. The belt also includes substantially inextensible fasts spaced transversely to the direction of belt travel. The fasts extend in the direction of belt travel adjacent to the teeth and are looped around preselected numbers of the teeth.