GB1106179A - Apparatus for indexing the work spindle in automatic lathes through predetermined angles of rotation - Google Patents

Abstract

1,106,179. Lathes. INDEX - WERKE KOMM. GES. HAHN & TESSKY. 9 Aug., 1965 [8 Aug., 1964], No. 34078/65. Heading B3T. In an automatic lathe the spindle 10 is stopped in predetermined positions by means of an index disc 14 attached to the spindle and engageable by a click-stop device 28 which is freed from a holding device 26 when the spindle is rotating at a slow speed, the holding device being deactivated by at least one releasing member 34 rotating with the spindle. The stop bolt 28 is moved towards the disc 14 by an electromagnet 32. The releasing means consist of magnetic pins 34, 36, 38 which give impulses to a device 42. In operation, the speed of the spindle is gauged by the impulses transmitted to the device 42 by the south pole of the magnet 34. When the spindle is braked and has been slowed sufficiently, a clutch is operated to engage a slow-speed drive. Operation of the device 42 by the magnet 34 then causes release of the plunger 28 and stopping of the spindle. A drilling or milling operation is then carried out. When the operation is complete, the electromagnet 32 is de-energized and the plunger 28 is withdrawn, causing a switch 44 to be actuated to re-commence the slow-speed drive. The spindle is stopped again at the notches 18 and 22, the notch 20 being inoperative due to the absence of a magnet. A second magnet 50 at the notch 22 sets the electrical control circuit to prevent further operation of the plunger 28. If more than one indexing revolution of the spindle is required, such as for drilling a series of holes in the circumference of a workpiece and then tapping them, an electrical counter is provided. In a modification, an indexing cycle is started by applying pressure to a piston 168, Fig. 5, to raise it and actuate a slow-speed switch 184. It also raises a rod 202 which is engaged with a slotted lever 224 and swings it to rock a bell-crank 234 and bring a roller into the path of a dog 144 on the spindle 130. When the dog 144 rocks the bell-crank, the lever 226 moves the rod 202 to release a catch 194 and allow the plunger 156 to engage a recess 134. Movement of the plunger releases a switch 164 to stop the slow speed drive. Indexing of the spindle follows in sequence as before.