GB604635A - Improvements relating to work centring machines - Google Patents

Abstract

604,635. Drilling-machines. MANCHESTER REPETITION ENGINEERS, Ltd., LIVING- STONE, H., and ROGERS, W. E. Nov. 29, 1945, No. 32290. [Class 83 (iii)] A centre-drilling machine comprises a headstock with a drill revolving therein, two spindles mounted for axial movement in the headstock at opposite sides of the drill axis, a cross-head connecting the forward ends of said spindles, means in the cross-head for receiving the end of the work-piece to be centred by the drill, springs resisting movement of the cross-head towards the drill, and adjustable means limiting such movement, a tailstock with means for carrying an end of the work-piece and means for traversing the work-piece towards the headstock. The centring machine in one form, Fig. 1, comprises a headstock a and tailstock b carried by a bed c, the tailstock being adjustable thereon to suit the length of the work-piece m to be centred. The centre drill g, Fig. 3, is carried in a collet type chuck tightened by a nut h in a spindle d rotated by a belt pulley e. A cross-head j, Fig. 5, is arranged centrally across the face of the headstock supported by a pair of spindles or rods i, slidable in the headstock and adapted to be moved rearwardly against the pressure of springs n. The crosshead carries a hardened steel bush at its centre having a conical recess to take the end of a work-piece. The tailstock has a non-rotatable sleeve q adapted to be fed axially by a hand wheel and rack-and-pinion gearing and has a bush with a conical recess to take the other end of the work. Axial feed of the tailstock sleeve presses the headstock end of the work against the resilient headstock bush and the work is thus centre-drilled. The depth of hole drilled is limited by an adjustable stop-bolt p. In a second form of the invention, Fig. 7, for drilling centre holes at each end of the work in one set-up, the tailstock B is provided, similarly to the headstock A, with a centre-drill and a resilient cross-head 9. The drive to the tailstock drill spindle is taken from a shaft j through a slidable pulley 4 which moves in unison with the tailstock through a fork-piece x carried by the latter engaging a groove on an extension of the pulley. According to the Provisional Specification the work-pieces may be fed into position and discharged automatically.