<p>1516719 Rotary positive-displacement fluidmachines M RADIVOJE and V STANISLAV 28 Oct 1975 [13 Nov 1974] 44321/75 Heading F1F In a pneumatic oscillating-vane motor for a windscreen wiper the flow of air to and from chambers 24, 25 on opposite sides of vanes 19 on a common output shaft 3 is controlled by an oscillating valve 6, which has inlet passages 22 therein communicating with an inlet channel in the shaft. To effect rapid movement of the valve at the end of each stroke of the vanes the valve is connected to the shaft by way of springs 7. The exhaust air is ejected through an expansion chamber 11. The vanes and the adjacent portion of the shaft are covered with sealing material. Seals 4 engage with the said portion of the shaft.</p>
