(under subclass 28) Subject matter wherein said parts transmitting rotary motion by surface friction of rolling contact include means to vary the rotational velocity of the output body divided by the rotational velocity of the input body. [figure] [caption] The turntable has a peripheral flange provided with an exterior annular recess 15 so as to give the turntable the character of a large pulley which is driven by means of an elastic belt 24 from a driving pulley 22. The arrangement is more specifically shown in the figure. The pulley 22 is rotatably supported on a spindle 18 which also supports a friction gear wheel 20 adapted to engage and be driven from a power spindle 10 of an electric motor 19 which is not shown in detail. The driving mechanism to be described hereinafter is constructed so as to enable the turntable to be rotated with a selected one of three different predetermined speeds. To this purpose the motor spindle 10 is provided with three sections 12, 14, and 16 of different diameters adapted to be selectively engaged by the friction wheel 20 which can be axially displaced.
