GB375007A - Improvements relating to clutches for drilling machines - Google Patents

Abstract

375,007. Friction ratchet clutches. ARCHDALE & CO., Ltd., J. and JEWSBURY, J., Ledsam Street, Birmingham. April 16, 1931, No. 11253. [Class 80 (ii).] A multiplate friction clutch for drilling machines has a pressure plate in screw-threaded connection with a member carrying some of the plates, and a spring, weight, or fluid operated device, acts on a lever controlling the pressure plate to hold the latter in its operative position. As shown a pressure plate g is screwed to a hollow shaft e which is driven by a pulley f and has clutch plates c. The coacting clutch plates b are carried by a member a secured to a toothed wheel u driving a shaft w. A rod i passing through the shaft e carries a pin j which extends through a helical slot k in the shaft e and is fixed to the plate g. The outer end of the rod i has a thrust bearing l carried by a member m screwed to a fixed member n. The member m has a handle p having a projection q with which a spring- urged catch r engages. A second rod i<1> screwed to the rod i is associated with a pressure plate g<1>, a clutch a<1> and toothed wheel u<1>, for reverse driving of the shaft w. The projection q has inclined side faces. Movement of the handle p so that the catch r engages one of the side faces of the projection q causes the pressure plate to engage the clutch plates b, c, the spring-t of the catch r tending to exert a slight pressure to hold the clutch in operation. Engagement of the catch with the other inclined face of the projection q engages the clutch a<1> and drives the shaft w in the reverse direction. In a modification the pressure plate g, Fig. 3, is operated by a pivoted lever p and a catch r when the clutch is in operation tends to hold the lever p in the operative position. In another modification the lever p is operated by a fluid controlled piston.