Patent GB-190103298-A (GB)
Title: Improvements in Machines for Making Screws and similar Articles.
Inventor: SITTMAN GUSTAV
Filed: 1901-02-15
Granted: 1901-10-12
Abstract: 3298. Sittmann, G., and Pitt, W. H. Feb. 15. Lathes.-Relates to turning-lathes for making screws and the like. Tools are fixed to the turret head 2, which rotates on the slide 3 and reciprocates with its slide upon the adjustable guide 4. The slide 3 is reciprocated by a r a c k 9, which gears with a pinion 8 engaging with a second rack 7 fixed to the slide. The rack 9 is reciprocated by levers 25, 30 pivoted on the rods 26, 31 and engaging with a cam 23, Fig. 6, on the longitudinal shaft 24. The cam has one edge 23<b> running parallel to the axis of the cam and bounding a rectangular face 23a. It has also a cylindrical part 23<g>, bounded on one side by an edge (not shown) parallel to the edge 23<b>, and on the other side by a spiral edge 23<f>. From the edge 23<b> to the edge 23<f> is the tapering working face 23<d>. By shifting the lever 25 parallel to the axis of the cam, different parts of the face 23<d> act upon it to vary its movement. The lever 25 is shifted automatically by the rod 32, lever 34, and cam projection 36 adjustable on the drum 37. The lever 25 acts on the rack 9 through the medium of a pivoted bail 27. The turret head 2 is rotated by a ratchet-wheel on the head and a pawl carried by the guide 4. A spring bolt 15 locks the head in position. The cam 23 is loose on the shaft 24, and is driven from the pulley 49 by differential gearing actuating the worm 47 and worm-wheel 40, which is connected to the cam 23 and like it is loose on the shaft 24. The rotation of the shaft 24 is always commensurate with that of the cam 23, by reason of spur gearing connecting the worm-wheel and shaft. A quick-return motion is given to the turret head by means of cam projections on a disc on the shaft 24 which trip a clutch so that the worm 47 is connected directly to the shaft of the pulley 49. The stock is held in the clutch 5, in front of which is the transverse tool-carrying slide 70, operated by levers and cams in a similar way to the rack 9. The stock is gripped by the longitudinal movement of the tube 108 acting on the jaws 109. This is effected by levers 111 acted on by the coned piece 115 shifted laterally by a cam-actuated slide. The levers 111 bear against the head 110, and press back the ring 112 fixed to the tube 108 by a'pin passing through a slot in the spindle 85. The stock is fed by the cam-actuated slide 119 engaging with the head 107 of the inner tube 105. The slides 119 &c. are acted on by cam projections on a drum. To vary the effect of the projection on the slide 119, and therefore to vary the feed, the slide 119, Fig. 17, may carry a lever 129 pivoted at 128 and vibrating between a stop 125 and a set-screw 127. The cam acts on the lever 129, and more or less of its motion is communicated to the slide 119 by adjusting the set-screw. The spindle 85 is rotated in either direction by pulleys 86, 87, either of which may be clutched to the spindle by shifting the sleeve 90. The sleeve carries arms 90<a>, 90<b> engaging with levers 97 which draw out or force in the cones 95 arranged between curved arms 94 fitting within the pulleys. The levers 97 are pivoted to the plates 88, 89, and the stems of the cones pass through these plates, which are fixed to the spindle 85. The sleeve 90 may be shifted automatically by a cam on the shaft 24.