| 摘要 |
<p>1477579 Centrifugal governor CHICAGO PNEUMATIC TOOL CO 30 April 1975 [3 June 1974] 17982/75 Heading G3B [Also in Divisions B3 and Fl ] A hand-held power-operated vertical-type grinding tool includes a pneumatic motor 11 e.g. of the sliding-vane type, and an air inlet port 33 controlled by a speed governor and an overspeed safety device. The governor may be mounted on the output shaft 21 and comprise a valve 38 biased to an open position by a spring 43 and operated by centrifugal weights 44, only the righthand half of this device being shown in Fig. 1. The safety device may comprise a leaf-spring valve 48 held open by a pin 51 with a spherical head 52 and resting on a fixed seat 55 from which it is dislodged by a weight 57, Fig. 3 on a leaf-spring 56 when the shaft speed becomes excessive, the spring being attached to a collar 45 carrying the weights 44. The air-flow to the port 33 through a handle 28 may be regulated by a manually-controlled throttling valve 29. The grinding wheel is indicated at 24.</p> |
