Abstract: A transmission ratio varying arrangement involves establishing transmission between a drive shaft and a driven shaft by two orbital systems, one for each shaft, and including gear wheels which move concentric to the respective shafts thereof. One orbital system is joined to the other by simple or composite conventional transmission elements, the radius of each orbit being variable simultaneously, maintaining the sum thereof constant. Each of the shafts is provided with an identical truncated thickening which is in direct position and which, acting as a wedge, contacts radial supports which are guided in holes made in a sleeve which is equally spaced from the holes and which is provided at its outer part with peripheral wings perpendicular to the shaft. The wings are provided with radial notches in which there are guided the shafts on which there rest the gear wheels which move when the thickened shaft and the sleeve turn in unison joined by keys.

Abstract: A transmission ratio variator establishes transmission between a drive shaft and a driven shaft between two orbital systems comprising gear wheels which move concentrically to their respective shafts and where the radii of each orbit are simultaneously variable. The gear wheels are mounted on shafts which are radially displaced in notches made in peripheric wings of sleeves joined to the control elements of the orbits. Each of the shafts of the gear wheels has a truncated thickening contained in a housing provided in each gear wheel. The shafts are axially displaced while blocked in and unblocked from the wheels depending on the direction of the displacement thereof which is controlled by a disc emerging from a ring which is displaced along the sleeve controlled by a double fork whose movement is controlled at will and is produced by conventional means.