Abstract: A notched transmission belt has a plurality of notches whose bottom in a cross-section taken along a plane orthogonal to the width direction of the belt includes a linear portion at a center, and recessed curved portions continuously formed at both sides of the linear portion.

Abstract: A notched transmission belt has a plurality of notches whose bottom in a cross-section taken along a plane orthogonal to the width direction of the belt includes a linear portion at a center, and recessed curved portions continuously formed at both sides of the linear portion.

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 flat belt transmission has two spaced flat pulleys and a flat belt reeved around the flat pulleys. Each pulley can have a plurality of crowns arranged in the width direction of the outer periphery thereof. The flat belt can be a plurality of belts with a narrow width, one for each of the crowns. The flat belt can be a single belt with a part extending in the longitudinal direction of the belt in its inner periphery. The flat belt can be used with the flat pulley of the above construction or a flat pulley having a single crown of its outer periphery. In addition, the plurality of crowns are formed on the outer periphery of the flat pulley so as to be spaced at the same distance from the center of rotation of the pulley, or the outer periphery of the flat pulley can be in the form of a circular arc to change height of the crowns.