GB359299A - Improvements in or relating to turning lathes - Google Patents

Abstract

359,299. Lathes. HAHN, H., HAHN, 0., and TESSKY, K., (trading as INDEXWERKE HAHN & KOLB), Esslingen-on. Neckar, Germany. Dec. 20, 1930, No. 38417. Convention date, Dec. 20, 1929. [Class 83 (iii).] In a lathe or like machine tool in which the clamping and feeding means for the workbar are actuated from a control cam c through levers d, f respectively, the cam c may be driven either directly from the main cam shaft a or indirectly from a driving shaft q which drives the main cam shaft through gearing r, t. The shaft q carries a wheel o engaging a wheel n fixed on a shaft m passing through a sleeve 4 carrying a wheel k connected to a wheel h secured to the control cam. A clutch member 3 splined on the sleeve 4 is normally urged by a spring 5 into engagement with the driven wheel n. The clutch is controlled by a lever w and cam x. When the lever is operated by its cam, a projection is withdrawn from a recessed groove 6, Fig. 6, in the clutch, thus allowing the spring to effect the engagement. After one revolution of the clutch, the lever drops into the recess 7 whereupon the inclined portion 9 of the recess causes the clutch to be moved axially to disengage the drive. In cases where the shaft a is driven sufficiently quickly for the feeding and clamping to be effected without undue loss of time, the wheel h is replaced by a clutch sleeve having a projection which couples the control cam directly with the shaft a. In a modification, Fig. 5, the wheel h is provided with a coupling part z<1>, the parts h, z<1> being moved axially by a hand-lever l to engage either the direct or the indirect drives. In a further modification the clutch 3 may be mounted on an extension q<1> of the shaft q so as to drive the wheel i directly from this shaft.