Patent GB-190100350-A (GB)
Title: Improvements in Automatic Metal-working Lathes
Inventor: POTTER JAMES CHARLES
Filed: 1901-01-05
Granted: 1901-10-05
Abstract: 350. Potter, J. C., and Johnston, J. Jan. 5. Lathes.-In an automatic lathe, the variablespeed gear for driving the mandrel b<12>, Fig. 4, comprises a driving-shaft b with pulleys b<2>, b<3> and a cone b<1>. A belt on the cone drives a cone b<4>, geared to a back shaft on which are two loose wheels of different sizes, gearing with wheels b<10>, b<11> on the mandrel, one pair having an intermediate wheel or wheels, giving different speeds in' the same or opposite directions. Either wheel on the back shaft may be clutched to the shaft by a handlever on the front of the headstock. The shipper b<16> for the cone belt is moved by a rack b<17> operated by gears b<18> and a sector lever b<19> moved by a cam drum b<21> on the shaft f<2>. A shaft c, which operates mechanism for reciprocating the turret slide, is similarly driven and controlled by the pulleys b<3> b<22>, cones b<23>, b<24>, stepped cones b<25>, b<26>, and a shipper b<161> and gearing b<171>, b<181>, b<191>. The shaft c, through worm gearing c<1>, c', Fig. 6, a shaft e, and pinion c<3>, drives a wheel c<4> carrying a crank-pin c<9> engaging a slotted lever c<12>, pivoted at c<13>, and connected by a link c<14> to a bracket d' on the turret slide d. The bracket is adjustable by a screw d' to shift the position of the traverse, and the crank-pin is carried by a slide on the back of the wheel c<4>, the slide being adjustable by rack and pinion gearing, operated by a shaft c<20>, passing through the centre of the wheel and operated by a handle at the front of the lathe, so that the length of traverse may be varied. The mechanism for connecting the worm-wheel c<2> to, or disconnecting it from, the shaft e is shown in plan in Fig. 21. In the position shown, the shaft c is driven at a slow rate by wheels e', e<2>, differing by one tooth and gearing with a pinion on the worm-wheel. The worm-wheel and the wheel e<2> are loose on the shaft, while the wheel e<1> is fixed to it. For the slow motion the wheel e<2> is held by a pawl e<19> engaging ratchet teeth e<7> formed on the wheel. A spring frame e<3>, carrying pins e<4>, , can be pushed forward by pins e<6> on a ring outside the whe el e<2> to lock the worm-wheel to the wheel e<1> when it is desired to run at a high speed. This coupling is effected by a tappet rod and bell-crank lever, operated by a hand-lever on the front of the machine, which may be turned in the opposite direction to disengage the pawl from the ratchet and allow the wheels to run free, thus stopping the traverse of the turret. The pawl is disengaged by a rod e<21> connected to a shipper e<14>, sliding on the shaft e and operated by the hand tappet rod. The shipper may be moved automatically by cams on a disc f<5> on the cam shaft f driven by worm gearing f from the shaft e. The cams are arranged to effect the desired changes of speed by acting on a lever f <8>, pressing against the boss e<20> of the shipper. The lever is held in the position shown by a latch f<10>, but, at the desired periods, the latch is tripped by pins f<11>, and the shipper returned by a coiled spring e<201>.. The shipper then operates a rod e<15> to couple the worm-wheel c<2> direct to the shaft e by a cup clutch e<16>, e<17> giving a high speed. At any desired period, say one complete revolution of the turret, along cam moves the lever f <8> sufficiently to stop the turret traverse by disconnecting the worm-wheel and shaft. The turret d<4>, Fig. 26, is locked by a spring bolt d<8> with a pin d<17>, engaged by a bell crank d<20> pivoted on the turret slide d. During the backward traverse of the slide the arm d<15> of the bell crank engages a switch d<18>, pivoted on a bracket d<13> adjustable on the lathe bed, causing the locking-bolt to be withdrawn. The turret is then given a step rotation by a fork d<10> engaging pins d<6> on the turret and operated by engaging with the arm d1<4 >of the bracket d<13>. The cross-slide g<2>, Figs. 4 and 15, carrying one or more slides g<6> is mounted on a saddle g, adjustable along the lathe bed. The slide is operated by a rack 9<4>, engaged by a pinion g<7>, on a vertical spindle on the saddle which carries a second pinion gearing with two rack rods g<9>, g<10> at the back of the lathe. These rods have adjustable tappets g<13>, g<14> and collars g<16>, g<17>, and a sliding block g<15.> An arm g<18> on the turret slide carries a bell crank g<19>, normally pressed towards the position shown in dotted lines by a spring. At desired positions round the turret, pivoted stops g<23> are placed which engage the arm of the bell crank when the turret reaches the proper angular position, and move it to the position shown in full lines During the back stroke, the arm wipes past the tappet g<14>, but, engages it during the forward stroke and pills for-' ward the rod g<10 >to feed the cross slide in one direction. During the return stroke, the arm engages the block g<15> and pushes back the rod, returning the cross-slide. By turning the stop g<23> to the position shown in dotted lines, the feed of the cross-slide is reversed. The bell crank may be swung aside when no cross-feed is required.