Patent GB-1492329-A (GB)
Title: Numerically controlled automatic lathe
IPC: B23B7/06
Filed: 1975-09-26
Abstract: 1492329 Automatic lathes CITIZEN WATCH CO Ltd 26 Sept 1975 [27 May 1975 1 July 1975] 39497/75 Heading B3T A numerically controlled automatic lathe comprises a headstock having a rotary work spindle and a plurality of tool holders mounted for movement towards and away from a workpiece carried in the spindle, the tool holders are actuated by a crank and lever mechanism from cam shafts the speed of rotation of which are controlled by reversible electric motors from a central A.C. system and which also controls the speed of rotation of the spindle and/or the displacement of the headstock. In each tool holder actuating means there is also provided an independently actuable connecting means whereby each tool holder with its appropriate cutting tool may be engaged or disengaged in relation to a predetermined operating sequence defined by the central control system, the operation of the connecting means also being effected from the control system. In the embodiments described the headstock 10 with its spindle 14 is actuated by motor 18 from the control system 20 and which in this instance controls the displacement of the headstock relative to the bed 12. A tool carrier 24 with a central bush 25 for supporting the workpiece, supports a plurality of radially movable tools 80, 82, 84 and a further pair of tools 26, 28 mounted on a lever 30 pivotable on the carrier 24 about an axis parallel to the workpiece and spindle. The tools 80, 82, 84 are actuated through a lever linkage 106, 102, 96, 92, from a first cam shaft 170 controlled by a reversible motor 162. The tools 26, 28 are actuated from a second cam shaft 182 controlled by a motor 164. A third auxiliary cam shaft 188 is provided for selective engagement by clutch means 194 or 196 with either the first and second cam-shafts 170, 182 for actuating, by way of a cam 58 and lever 72 a further tool holder 32 which is coaxial with the workpiece. In each of the drive mechanisms for each individual tool and tool holder there is provided a connecting means whereby the drive from the respective cam-shaft can be selectively disconnected to permit selective use of the cutting tools whilst continuously rotating the cam-shafts. The connecting means for the tools 80, 82, 84 is provided at the end of lever 96 at the location of rod 102 and is formed by an L-shaped bracket actuated by a solenoid to displace the end of the rod 102 from engagement with a pin 104 thereby immobilizing the respective tool and holder 82 (see Fig. 6). For the tools 26 or 28, a pivotable stop 140 is actuable to engage or disengage with the lever 30 to stop the cutting movement of the tool 28 or by way of a solenoid actuated rack-and-pinion 128a, 132a means to pivot the cam follower 130 out of engagement with the cam 54 on the shaft 182 (see Fig. 4). A similar pivoting arrangement is provided at the end of lever 72 which operates tool holder 32, a solenoid operated rack-and-pinion 154, 154a and 152 pivots the cam follower 150 out of or into engagement with cam 58 on the auxiliary camshaft. The operation of the motors 162, 164, the connecting means solenoids and the clutches 194, 196 by solenoids 216, 234 and the headstock motor 18 in a controller sequence by the control system 20 permits a variety of operations to be performed on a workpiece sequentially or simultaneously thus fully utilizing the operating time of the lathe. Additional tool holders may also be incorporated in the lathe such as obliquely mounted holders (260), (262) and or parallel holders (32a), Figs. 12, 13 and 14 (not shown).