Patent GB-664265-A (GB)
Title: Machine tool of the screw machine type
IPC: B23G1/04
Filed: 1949-02-11
Abstract: 664,265. Turret lathes. GEAR GRINDING MACHINE CO. Feb. 11, 1949 [Feb. 24, 1948], No. 3822/49. Class 83 (iii). [Also in Group XXIV] An automatic screw. machine comprises a bed A on which are mounted a work-holding spindle B and a tool holding and operating unit assembly G, the latter being adjustable as a unit along a slideway A<SP>1</SP> of the bed relatively to the spindle and comprising a base G<SP>1</SP> having mounted for reciprocation thereon a carriage H provided with an obliquely-arranged tool turret I, which carries the end working tools, an electric motor G<SP>3</SP>, and an operating mechanism for the carriage and turret, actuated by the motor C<SP>3</SP>, and including a step-down transmission. The operation of the machine is controlled by a cam-shaft J driven from the motor G<SP>3</SP> at greatly reduced speed by means of a transmission including a two-speed pulley and belt connection 10, change gears and a clutch, Fig. 12 (not shown). The unit assembly G is adjustable along the slideway A<SP>1</SP> by means of a lug G<SP>6</SP>, Fig. 3, and a fine pitch adjusting screw G<SP>7</SP>. The carriage H is moved-against the action of return springs by means of a cam J<SP>2</SP> mounted on an auxiliary cam-shaft J<SP>1</SP> driven from the cam-shaft J, the cam J<SP>2</SP> being adapted to engage a roller 38 mounted on a rockable member 37 connected to one end of a rod 36 the other end of which is connected to the adjustable crankpin 35 of an eccentric mounted on a shaft 33, Fig. 14, geared to a shaft 30a which at one end has a swivel engagement with a gear housing H<SP>1</SP> on the carriage H and at the other end is splined within a hollow shaft driven from the motor G<SP>3</SP> through a transmission including a clutch 31. The shaft 33 is geared to a shaft 43, Fig. 14, a disc head 44 on which has projecting therefrom a crank-pin 45 which, during each revolution of the disc head, is adapted to engage one of a number of slots I<SP>3</SP> on a conical member I<SP>2</SP> mounted on the turret shank I<SP>1</SP>, to index the turret. The turret is locked after each indexing operation by means of a spring-pressed locking bolt I<SP>4</SP> which is withdrawn, when necessary, by means of a cam-operated lever I<SP>8</SP>. The clutch 31 is normally held disengaged by a pin 46, Fig. 7, engaging an annular groove 47 in the clutch sleeve, the pin being carried by a rock arm 48 from which a bell-crank arm 49 extends into proximity to a rotary head 50 splined to the cam-shaft J, the head 50 having series of adjustably-positioned trip cams 51 thereon. A finger 52 on the arm 49 is actuated by each of the cams 51 to rock the arm 49 and thereby withdraw the pin 46 from the groove 47. The clutch is engaged but immediately after this, i.e. at the end of a revolution of the shaft 30, the pin 46 re-engages the groove 47 and a cam 47 a in the groove engaging the pin moves the clutch sleeve out of clutching engagement. Side operating tools are carried on cross slides controlled by means of cams K, K<SP>1 </SP>on the camshaft J. The spindle! B is driven by an independent electric motor and is controlled as to speed of rotation, direction of rotation, and chucking and releasing of the work by means of trip mechanisms, Fig. 17 (not shown).