Patent GB-467972-A (GB)
Title: Improvements in lathes and like machine tools
IPC: B23Q15/00
Filed: 1935-12-20
Abstract: 467,972. Lathes. JONES & LAMSON MACHINE CO. Dec. 20, 1935, No. 35340. Convention date, Dec. 20, 1934. [Class 83 (iii)] A lathe or like machine tool has the spindle driven by a motor 5 which is started by means of a push button which may then be released while the motor runs on until stopped either at the end of a cycle, or by a manual control, further means being operable to cause release of the button, after starting, to stop the motor. The motor armature shaft 7, Fig. 7, carries a brake drum 8 and is connected by a gear train 11 ... 18 with the work spindle 3. Between the frame members 20, 21, is arranged a rockable and axially movable tool bar 25 carried in spaced bearings 28. A second tool bar 35 having rocking movement only is arranged at the back of the bed. The front tool bar carries an arm 40 with an adjustable slide 41, Fig. 3, and the angular position of the arm is determined by a shoe 45 engaging a former cam 45 adjusted by screws 47 on a slide 48 which in turn moves along a pivoted track member 49 which is angularly adjusted by screws 50. The slide 48 is actuated through a link 55 from an arm 57 actuated by cams on the drum 88 carried by the cam shaft 80. Axial movement of the tool bar is effected by cams mounted on a second cam drum 72. The cam shaft terminates beneath the spindle nose so as to leave a free chip receiving space between the frame members 20, 21. The back tool bar 35, Fig. 3, carries a tool holding arm 100 fitted at the rear with a circular bar 102 adjustably clamped in a split bearing and pivoted to a shoe 106 engaging a former cam 110. This cam is secured to a slide 112 moving in an adjustable guide similar to that for the cam 46. The slide 112 is actuated by a link connected to a slide actuated by cams on the drum 72. The shoe 106 is kept against the former by a. weight. The cam shaft is driven through worm gearing from a shaft 86 having selective high and low speed drives. The high speed drive is derived from the motor shaft 7 through bevel gearing 150, shaft 152, Fig. 10, bevel gearing 156, spur gears 155 and clutch collar 167. A pulley 160 driven from this gearing drives a coolant pump (not shown). The low speed drive is derived from the spindle 3, through bevel gearing 176, which drives a shaft 177 extending into a partitioned gear box 180 and driving through a train consisting of change gears 187, 192, 1920 and 1960 and further gears 195, 200, a gear 201 connectible by a clutch 203 with shaft 87. Loose gears 190. 185 are driven from this train to carry lubricant to the upper part of the gear box to a lubricating channel 183, and the train may be interrupted by sliding the gear 195 out of mesh by means of an external crank arm 210. The high and low speed clutches are selectively actuated by a connecting link 212 operated either from a hand lever 220 or automatically by cams on the main drum acting on a follower 2210. Load-and-fire quick change mechanism is provided at 224. The clutch 203 has a resilient clutch portion so that it is disengaged by the overrunning action of the high speed drive thus preventing both drives being out of engagement at the same time. The cam drum 88 also carries a cam 250 which at the end of a cycle opens a switch 252 in circuit with the motor 5 to stop the machine. The interruption of current also de-energizes a brake release solenoid 253 to permit a spring 254, Fig. 7 to engage a pair of hinged shoes 255, 256 with the drum 8 to stop the motor shaft quickly. When solenoid 253 is energized an arm 266 of a bell-crank' lever 261 pivoted at 260 to the arm 257 is pulled downwards to separate the brake arms and release the brake but when the solenoid is de-energized the spring 254 reacting between the arm 257 and one end of rod 264 lifts the arm 266 and applies the brake. The wiring diagram for supplying the motor with three phase current is shown in Fig. 12. When the switch 301 is closed, depression of a starter button 294 actuates the solenoid 284 and closes switch 283 thus starting the motor 5. On release of the button a branch circuit 300 including a stop button 291 still remains closed to supply the solenoid and maintain the motor running. In this' condition the machine may be stopped at any time by depression of the stop switch 291 or, at the end of the cycle, by the actuation of switch 252. If however the switch 301 is opened, for setting up the machine, the branch circuit 300 is broken and then the motor will operate only so long as the starter button 294 is depressed. The cam drum may also be turned over by hand when required.