Patent ID: 6409584
Filing Date: 2002-06-25
Classification: B24B

Abstract:
A speed adjusting device for a pneumatic grinding tool, comprising:an axle having a passage defined longitudinally in a rear end thereof and a plurality of apertures defined in an outer periphery of the axle at equal intervals, said apertures communicating with said passage, a front end of said axle connected to a rotator; a base being a circular member and mounted to said axle and rotated with said axle, said base located in front of said apertures, a plurality of paths located in a periphery of said base at equal intervals; a plurality of slide members respectively and movably received in said slide paths; a disk having a circular body and a flange extending from a periphery of a front side of said body, said flange having an inclined cone-shaped surface defined in an inner surface thereof, a mount hole defined through a center of said body, a neck extending from a rear side of said body along a periphery of said mount hole, a plurality of air holes defined through said neck at equal intervals, said disk movably mounted on the axle by said mount hole and rotated with said axle, the flange covering the outside of the base, said slide members could contact said cone-shaped surface of said flange, said air holes located in alignment with said apertures; a spring pushing said disk which is maintained to slide forward and positioned at a normal position; whereby said air holes located in alignment with said apertures when in normal condition; said air holes located off alignment with said apertures when a rotational speed of said rotator is over speed and the disk is pushed backward by the slide members affected by centrifugal force.