Fecha de publicación: 06/11/1913 Fuente: WIPO "pollen" 360. Pollen, A. H., and Isherwood, H. Jan. 5. Variable-speed friction-gearing.-A friction disk A is continuously rotated and spring-urged towards a ball B which is adjustable radially across its surface. Motion is transmitted from this ball to a pair of rollers R1, R2 engaging by spur-gearing a shaft T which is thus driven at a variable rate.