Abstract: The working apparatus, useful as a cleaning apparatus for textile machines, comprises a mobile servicing or working unit possessing a ventilator cooperating with air guide elements and operates in cleaning zones located at these textile machines. The servicing unit is movable on a track or rails. A stationary drive motor provides the relatively high power drive for the travel motion of the servicing unit along the track and for the ventilator by means of an endless belt trained over transmission members arranged at the servicing unit. These transmission members each contain different size coaxially arranged pulleys. By changing the position of one strand or run of the belt from a smaller size to a larger size pulley and vice-versa, the direction of movement of the travelling servicing unit can be selectively reversed. The movement of the servicing unit is monitored by a control device arranged at the servicing unit with the aid of terminal or limit switches and sensors.