Improvements in Machines for Cutting Off Lengths from Metal or other Bars, for Surfacing, and for similar Operations.

摘要

109,876. Taylor, Ltd., C., Taylor, G. B., and Broadfoot, W. H. Nov. 15, 1916. Lathes.-In a lathe for cutting off lengths from metal &c. bars, and for surfacing &c., the cutting speed of the tool in the rotary tool head is maintained constant bv changing the speed of rotation of the head in inverse ratio to the change of diameter of the work. The movement of the cutter is transferred to a switch controlling the actuating-motor through a cam shaped to produce the desired result. The tools are returned to their normal positions, while the speed of the main spindle is a maximum. The tools d6 are secured to slides d5 actuated by screws d8 which are driven by worm gears, e, e2 and toothed wheels g3, g4 from a ring g freely mounted on the spindle d2 and connected to a chain drive g5. If the ring g is rotated on the spindle d2 while it is revolving and in the same direction, the tool d6 is advanced. If it is held stationary, the tool retires, and if the ring is uninfluenced, i.e. rotates with the spindle d2, the tool is unaffected. The main driving shaft c2 actuates the head d by a pinion c3, and a side shaft l by bevel gearing which actuates a speedgear wheel i3 and a pinion i'. The wheel i3 drives either of the three wheels j which by a clutch revolves a second shaft k, which is chain geared to the ring g. Disengaging the clutch j2 leaves the shaft free. The rotation of k rotates wheels k3, k4 and a screw m which engages a screw box n driven from the pinion i4 by means of a wheel n2 and sleeve n3. The box n is connected to a rack which rotates a cam r to actuate a switch t. When the switch engages the bottom stop to produce maximum speed, it is held by a catch bar v while the cam r moves back to normal position again with the cutting tools fully retired. The bar v is then released by a hand lever v3 connected to a brake annulus w, or automatically. In the position shown. the ring g is being rotated and the tool slide d5 is moving inwards. When the tool d6 reaches its inmost point, the lever x is actuated to disconnect the clutch j2 from the. speed gear and connect it with the brake annulus w to hold the shaft k stationary to retire the tool. The lever v3 is then moved to the left to disconnect w and release the rod s. The tool and cam now become inoperative until the clutch j2 registers again with the speed-gear wheels.