Patent GB-189809702-A (GB)
Title: Improvements in Lathes or Screw Making Machines.
Inventor: DAVENPORT WILLIAM SIMEON
Filed: 1898-04-27
Granted: 1898-11-05
Abstract: 9702. Davenport, W. S. Oct. 4, A.D. 1897, [date claimed under Sec. 103 of Patents &c. Act A.D. 1883]. Lathes.-Relates to lathes in which a rod or stock is intermittently fed forward, held by a rotating chuck and successively acted upon by a series of tools to form the required article, such as a screw. Figs. 1 and 2 show elevations from opposite sides of the lathe. The rod is passed through the hollow spindle of the headstock 3, provided with a chuck, the jaws of which are operated by a sleeve 2, levers 4, collar 6, lever 7, and cam 10 on the shaft 11. The rod is fed forward intermittently by a tube 12, with the usual spring fingers, reciprocated by a cam 13 on the shaft 11, and the lever 14, connected by the stud 15 to the slide 16 attached to the tube 12 by a pivoted arm 19. The stud 15 is adjustable by the screw 23 to vary the feed, and the grooves in the slide 16 and lever 14 are arranged to be parallel at the forward position of the lever, so that the stock is always advanced to the same point. The hollow spindle is driven. in either direction by oppositely-rotating pulleys 38, 39, and a clutch 40 operated by a lever 41 and cam 43. The cam 43 is keyed on a sleeve 47 provided with a clutch 45 constantly forced, by a spring 48, to engage a clutch 44 on the shaft 26. Normally the clutch is held out of action by one of the cams or projections 51 or 52 engaging the abutments 49 or 50 on spring levers 53, 54. The levers are struck by tappets 53<1>, 54<1> on a disc 55<1> mounted on the shaft 56<1>, to release the clutch and allow the cam 43 to be rotated through half a revolution, when the clutch is again disengaged. One abutment only may be used, engaged by both cams. A pin on a spring arm 57 enters notches in the clutch 45 to prevent the cam 43 from rotating too far. The cam shaft 11 is rotated at the required times through one revolution by gearing at 62, the wheel 62 being connected to and disconnected from the shaft 26 by the clutch mechanism 58, 60, cam 66, abutment lever 67, stop lever 69, and tappet on the disc 68<1> on the shaft 69<1> acting in a similar manner to the mechanism described in connection with the cam 43. The various tools are secured in a turret head 70 mounted on a shaft 71 in a slide 72, and the turret is rotated intermittently to bring various tools successively into position by a crank-pin 74 on a disc on a shaft 75 engaging slots 73<1> in a disc 73 on the turret shaft 72. The shaft 75 is driven by spiral gearing at 77 and spur gearing 79, 80, 81 from the shaft 26. The wheel 81 is provided with engaging and disengaging clutch &c. mechanism similar to that described in connection with the wheel 62. The pinion 79 is broad enough to be always in gear with the wheel 80 during the reciprocation of the slide 72. In case the turret is to be rotated through two or more steps at once, two or more tappets for actuating the lever to hold the abutment 84 clear of the cam 85 may be placed close together on the disc 90<1>, but, preferably, the wheel 80 is provided with pins 95 which can project to operate on an extension of the abutment lever. The turret is locked by a spring bolt entering recesses in the turret. As the pin 74 enters and leaves the slots 73<1> while moving radially to the disc 73, the locking-bolt may be disengaged by a cam on the shaft 78, and again engaged after the pin 74 enters and before it leaves the slots 73<1>. The turret is preferably advanced slowly while the tools are cutting by cam mechanism, and is returned by more rapidly acting mechanism, which also advances the turret to bring the tools up to the work. A crank-pin 102, Fig. 8, on the shaft 75 is connected by a rod 103 to a bar 104 which can move in the slide 72. Surrounding the bar 104 is a U-shaped block 107 provided with teeth engaged by a toothed segment 110 on a lever 111. During the cutting action of the tools, the block 107 abuts against a shoulder 108 on the bar 104, and the slide 72 is advanced slowly by the cam 114 and lever 111 till the end 106 of the bar 104 abuts against a stop 105 on the machine frame. In this position the abutment 84 is tripped and the shaft 75 rotated through one revolution, and the crank 102 will at first cause the turret slide 72 to be withdrawn quickly, the bar 104 being prevented from moving. The block 107 moves slowly back, and when the turret has been rotated one step, the slide 72 will be moved completely back against the stop 105, and the further rotation of the shaft 75 will move the bar 104 back. With small articles, the backward motion of the block 107 is short, and the shoulder 108 coming in contact with this block causes the crank 102 to advance the slide 72 during the latter part of the rotation of the shaft 75 to bring the tools quickly up to the work. The cam shaft 120 is driven from -the shaft 26, through the changewheels 131, worm gearing 129, 128, cross-shaft 127, and spur gearing. The shaft 69<1>, driven from the shaft 127 by bevel gearing 132, 133, carries two changeable cams 134, 135 for operating the transverse tool slides 136, 137. The shaft 56<1> can be connected to the shaft 69<1> by a coupling 138, 140. The shaft 26 can be connected to and disconnected with a shaft 28 carrying the driving- pulley 31 by a clutch 32 controlled by hand. The cut-off blanks fall down a shoot in the frame, and are deflected to separate them from the turnings &c. by falling on to a deflecting-plate oscillated by a cam at the proper time.