Abstract: A method of making elements with profiled cross-section from sheet metal for use in a driving belt by a rolling process, for providing a strip with a middle groove in longitudinal direction and by rolling the material continuously symmetrically with respect to that groove to two profiles punching out the elements on both sides of the middle groove, with their longitudinal direction in the direction of movement of the strip, according to lines which are located at accurately predetermined distances on both sides of the groove.

Abstract: A method of providing transverse elements to be arranged in a consecutive series side by side on a driving belt with curved surfaces by which they support the driving belt. The surfaces obtain a curvature by replacing the driving belt by an endless grinding band having grinding material on its inner side engaging the said surfaces and running the whole on two pulleys, one of which has a smaller diameter than the other one. The grinding band has longitudinal zones with different abrasing capacities, for example by providing the band with a longitudinal range of gaps in its middle zone. In this way the supporting surfaces obtain simultaneously a curvature in the running direction of the belt and in a direction opposite thereto.

Abstract: A fully hydraulic control mechanism for an infinitely variable cone pulley gear. The torque is transmitted by the intermediary of an oil cushion in a coupling between a driving and a driven element providing for a torque-dependent oil pressure in an oil circuit. The oil circuit delivers pressure on surfaces of different size of axially movable discs for primary and secondary cone pairs between which a transmission belt is running.The oil circuit leads from the primary to the secondary cone pair through a pressure reduction device which is under speed-ratio progressive control.