GB167664A - Apparatus for machining propeller blades - Google Patents

Abstract

167,664. Stone & Co., Ltd., J., and Peters, P. M. July 6, 1920. Shaping helical surfaces.-In a machine for shaping propeller blades or similar helical surfaces of the type in which the work is mounted on a rotary table while the tool is reciprocated radially along a main guide mounted on saddles carried on two vertical columns, the reciprocation of the tool saddle and the main guide and table feeds are all operated from a single shaft. A rotary work-holding table a having radial T slots b and a central hole b<1> is mounted on a vertical spindle c and supported near the periphery by taper rollers d. Vertical columns f, h, provided with leading-screws k, m operating main guide saddles n, p respectively, are secured by brackets to a wall g<1> supported by a girder g<2> and are connected at the top by a bridge-piece q. The leading-screws are operated through worm gearing from a cross-shaft r carrying a bevel-pinion driven from a shaft 58. The main guide t is pivoted at t<3> to the saddle n and is slidable in a guide t' pivoted to the saddle p so that if necessary the main guide may be inclined to the horizontal. The tool-bar 4 is adjustably secured to a saddle u reciprocated with a quick return by an oscillating link 15 driven from a crank-disc 9 on a shaft 8. An adjustable counterweight 18 mounted on an arm secured to the link 15 serves to balance the weight of the tool saddle for different inclinations of the main guide and the connecting-rod 22 which is braced by tie-rods 27 and a strut 28 is adjustable in a bearing v on the tool saddle by means of a screw 24. The main driving-shaft 33 is driven through a gear box 32 from an electric motor 29 and is connected by bevel-gearing to a shaft 37 carrying a feathered worm 39 driving the crankdisc 9. An extension of the main driving-shaft drives through a second gear-box 45 and suitable gearing a crank-disc 50 operating a ratchet-wheel 56 on a countershaft 57 driving the feed-operating shaft 58. Gearing 59 and a hand-wheel 60 are provided for hand operation of the tool-feed. The intermittent table feed is also actuated from the countershaft 57, which carries a worm driving a worm-wheel on a shaft 75 connected through change-speed and bevel gearing to a shaft 80 carrying a worm engaging a worm-wheel 82 secured to the table. To provide a quick return of the vertical saddles and the work-table, the motor 29 and the ratchet gear are disconnected and a bevel-pinion 84 on the shaft 58 is driven from an auxiliary motor 89 through a handoperated reversing-clutch 87.