Patent GB-149955-A (GB)
Title: An improved automatic lathe
IPC: B23B9/02
Filed: 1920-07-26
Abstract: 149,955. Whitaker, C. G. Aug. 19, 1919, [Convention date]. Lathes; chucks.-In an automatic turret lathe operating on 'bar stock, the turret is carried on a horizontal arm which is reciprocated and indexed by means of a cam drum loosely mounted on the hollow work spindles The turret head 29 is mounted on an arm 27 which is reciprocated from a cam drum 32 by means of roller pins 34 extending radially from a series of plane faces on the turret arm engaging removable cam strips 33. The cam drum is arranged to make one rotation for each complete reciprocation of the turret arm. The latter is indexed at the forward end of its travel by means of a roller 38 which disengages a spring-pressed stop 42 located in one of a number of notches 37 in a feathered disk plate 35 and rotates the turret arm until the stop drops into the next successive notch. The turret is accurately positioned by means of holes bored in the head adapted to fit successively over a fixed pin 31. The cut off tool spindle 28 carries a tool arm 43 held normally clear of the work, as shown in Fig. 5, by a spring 44, the forward end of which is secured to a feathered boss 45 carrying a cam arm 46. A rocking spindle 47 carries downwardly extending levers 49, 51 having rollers 50, 52, the former of which engages a flat .cam plate 53, Fig. 5, appropriately located on the turret arm. This rocks the spindle 47 and the roller 52 moves back the boss 45 and its cam arm. The latter then engages the roller 38 to swing the cut-off tool downwards on to the work. The work feed is effected by two complete reciprocations of the turret arm after the operation of the tools. The feed tube 25 is actuated by a double lever 56 pivoted at 57 and carrying a double pawl 59 engaging adjustable stops 60, 61 the latter being resiliently mounted on the end of the turret arm. The opening and closing of the collet 24 are effected through a double lever 68 pivoted on the cutting-off tool spindle and having a double pawl 77 engaging adjustable stops 75, 76 on the turret arm. On the first backward movement of this arm, the feed tube is drawn back over the work. The arm then moves idly forward, and on the next backward movement a collar 70 releases the knobs of pivoted' levers 72 and allows a sleeve 54 to move back from a wedging collar 55 and the collet to open. On the next forward movement the work is fed and the levers 72 actuated to close the collet..The power shaft 80 may be clutched by hand-operated means to a driving sleeve 81 which drives a pinion 92 on the work spindle through gearing 93, and a countershaft 86 through sprocket and spur gearing 88 and clutch 89. The pinion 92 also drives through gearing a worm wheel 97 mounted on a sleeve 98 connected bv a free-wheel d'evice to the countershaft which may thus be driven at a low speed when the clutch 89 is disengaged. The cam drum is driven from the countershaft through a worm 90 and worm wheel 91, and its two speeds are controlled automatically by the reciprocation of the turret arm. The clutch 89 is operated by a bar 100 having a block 104 engaged by a lever 103 pivoted on a fixed arm and carrying a spring pawl 105 at its pivot point. At the beginning of the backward working movements of the turret arm a number of pins 106 successively engage the pawl 105 and turn the lever 103 to move the bar 100 which disengages the clutch 89 and imparts a slow feed to the cam drum. To give the quickreturn motion, the clutch 89 is engaged by a reverse movement of the bar 100 which is effected by the engagement of a projection 107 on the bar with a pin 108 fixed to the back of the worm wheel 91.