Patent GB-1167629-A (GB)
Title: Machine Tool
IPC: B23Q5/18
Filed: 1967-11-06
Abstract: 1,167,629. Boring machines. DEVLIEG MACHINE CO. 6 Nov., 1967 [15 Dec., 1966], No. 50412/67. Heading B3C. [Also in Division F2] A machine tool, such as a horizontal boring and milling machine, is provided with a series of clutch-operated constant mesh change speed units between the drive motor and tool spindle, and with control systems for ensuring that the drive cannot be started until the clutches appropriate to the desired speed ratio have been fully engaged and also permitting preselection of spindle speeds and feed rates to be effected during a machining operation. Machine details (Figs. 1, 2).-A bed 20 carries a saddle 21 supporting the work-table 22, the bed 20 being formed integrally with a vertical column 23 supporting and guiding a spindle head housing 25 for vertical movement. The spindle bar 29 is mounted in a sleeve 26 supported by bearings 27, 28. Feed and speed are adjusted by controls 236, 237, while the reversible drive motors are controlled by a switch 235. A boring-tapping selector switch 241 is also provided. Speed drive arrangement (Fig. 3).-The spindle 29 is driven by an electric motor 34 through a series of constant mesh ratio units, the clutches of which are operated by shift rods 67, 79, 93, 105, each controlled by solenoid-operated hydraulic actuators, e.g. shift rod 67 is operated by an actuator 68 and a valve 112 controlled by solenoids Sol. DR and Sol. DL. The rod 67 has an extension with a reduced diameter portion 142 operating limit switches LSDL and LSDR according to the position of the associated clutch fork 66. The motor 34 provides main and creeper drives through clutches 44, 47 and brakes 46, 53, the clutch 47 driving through worm gearing 51, 52, and the clutches being controlled by solenoid valves 113, 117. The desired speed is set by control member 237 having switch contact assemblies, Fig. 9 (not shown) controlling solenoids AL, AR . . . through latching relays CRBS, CRBT . . ., Figs. 15-18 (not shown), the solenoids being energized to engage the appropriate clutch units. Full engagement of the clutches causes closing of the appropriate limit switches LSDL, LSDR . . . and when this state has been attained the solenoid E and valve 113 operate to engage clutch 44 and release brakes 46, 53 to render effective the drive between motor 34 and spindle 29. Feed drive arrangement (Fig. 4).-For normal slow feed rates a lead screw 40 is driven by the motor 34 and drive spindle 29 through pinions 171, 172 and constant mesh ratio units with clutch shift members 205, 206, 207 operated by actuators 210, 212, 214 and solenoid valves 221, 226, 229 under the control of switch assembly 236, Fig. 10 (not shown), the contacts of which operate through latching relays to energize the solenoids S, T, U, Figs. 15-18 (not shown). For rapid feed rates a high speed motor 35 drives lead screw 40 through a clutch 151 conrolled by a solenoid valve 231, and through gear pinions 155, 156, 157. The forward and reverse drive selector switch 235 selects the low speed motor 34 in positions 1, 2 and the high speed motor 35 in positions 3, 4. The boring-tapping selector switch 241 operates to prevent the use of certain high feed rates during these operations. Manual feed of the spindle 29 may be obtained from a hand wheel 166a driving through pinions 166c, 166d, 167. Speed and preselection.-As soon as spindle 29 is rotating at sufficient speed a plugging switch 82 on the intermediate shaft 54, Fig. 3, operates to energize a relay (CRSP2) and open contacts (CRSP2c), thereby disabling the entire latching relay circuit, but not disturbing the existing speed and feed settings. In this condition the switch assemblies 236, 237 may be adjusted for new feed and speed settings without interfering with the machining operation then in progress. This forms the subject matter of divisional Specification 1,167,630. Clutch details (Figs. 5-8, not shown).-The clutches are of the dog type with facial teeth, engagement being facilitated by forming alternate teeth (143, 144 and 146, 147) of greater and lesser axial depth respectively.