Patent GB-477383-A (GB)
Title: Improvements in lathes or other machine tools
IPC: B23Q5/18
Filed: 1936-03-23
Abstract: 477,383. Lathes. WARNER & SWASEY CO. March 23, 1936, No. 8598. Convention date, Dec. 11, 1935. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 9, 1936.] [Class 83 (iii)] [Also in Group XXIV] A lathe or other machine tool has a movable part such as a spindle operated by changespeed gearing controlled by means which actuate an indicator indicating the different sequential operative steps of a work cycle and the speed of the spindle &c. for each such step. In addition to a turret slide (not shown), the bed carries a slide rest 23 having a cross slide 25. The work spindle 26 is driven from a main shaft 27 connected to a two-speed electric motor and carrying a splined clutch member 27f coacting with loose clutch members 27b, 27c on gears 27d, 27e respectively. These gears are connected directly or through an idler with gears 28a, 28b on a second shaft 28 which may thus be driven in either direction. The shaft 28 carries a sliding three-step cluster 28c coacting with gears 29a ... 29c on a third shaft 29. A sliding pair 30a, 30b on a fourth shaft 30 selectively engage gears 29d, 29a on shaft 29 and a second sliding pair 30c, 30d on shaft 30 coact with gears 26a, 26b on the spindle which may thus be driven at twelve speeds in either direction for each speed of the main motor. A slow power drive is imparted to the change-speed gearing preparatory to and during the shifting. For this purpose the main shaft 27 carries a gear 27h engaging a gear 31a on a flange sleeve 31b rotatable on a second flanged sleeve 31c. Sleeve 31b carries double pinions 31d, one pinion engaging a fixed internal ring and the other, with one more tooth, engaging an internal gear. on the sleeve 31c, which is thus slowly driven in the same direction as sleeve 31b. The sleeve 31c is connected by an overrunning roller clutch device to a sleeve 31f keyed to a shaft 31 so that the shaft is driven slowly through the roller clutch except when a high-speed drive of shaft 31 is operative. Gears 31o, 31m loose on shaft 31 engage respectively with gears 27d, 27e on shaft 27 and are selectively clutched to a splined clutch member 31n. Thus, while the clutch 27f is in neutral and the clutch 31n engaged, the work spindle is driven slowly in either direction. As soon as the clutch 27f is engaged, the slow drive is overrun and one of the normal drives is imparted to the spindle. The clutch member 27f is shifted by means of a yoke 32 on a slidable rod 32a, Fig. 5. Clutch member 31n is similarly shifted by a yoke 33 on slidable rod 33a. The three-step cluster 28c is shifted by a yoke 34 and the sliding pairs 30ab and 30cd by similar mechanism. The gears are shifted by means of a pair of endwise movable and rotatable spools 39a, 39b having three series of thirteen co-operating pairs of projections (one for each speed and a neutral) and operating in the manner described in Specification 475,960. The spools are indexed by rotation of the shaft 39. The spoolseparating sleeves 40a, 41a are interconnected by a rockable bar 42 on a shaft 42cz actuated by a lever arm 42b, Fig. 8, and remote controls mounted on the slide rest 23 is provided for this mechanism. A speed indicating dial 44 is mounted on a vertical spindle 43 geared to a longitudinal shaft 47, Fig. 1, connected through further gearing, to the speed selecting spools 39a, 39b. A control lever 50 is connected by lever mechanism, Fig. 3, to a shaft 51 connected to a shaft carrying lever, arms for operating the forks 33, 32 of the clutches 31n, 27f respectively. When the lever 50 is in neutral position N, both clutches are disengaged. In position A, only the clutch 31n is engaged to give the slow forward drive and in position F the selected fast speed is engaged, the low speed being overrun. The positions Band R give similar slow and fast drives in the opposite direction. The shaft 51 of this mechanism carries a contact arm 54, Fig. 8. Normally, when the lever 50 is in neutral the selector spools are held together by a solenoid 57 drawing down a bar 57a, but when the position A is reached, contacts 54a, 53a are brought into engagement to close the circuit of a solenoid 60 and act through a relay switch 58b to de-energize the solenoid 57. This moves the arm 42b to the dotted position and separates the spools. Further movement of the lever to position F starts the operative movement and the operator preselects the next speed by turning the dial 44. When a, speed change is required, the lever is moved back to A, for the slow drive, thus breaking contacts 54a and allowing switch 58b to energize solenoid 57 and move arm 42b to move the spools inwardly and engage the preselected speed, the slow drive still being operative. When the position N is reached the slow power drive is stopped. The lever is then moved back to F thus separating the spools and starting the preselected fast drive. For production work an indicator 59 mounted on the headstock is employed. This comprises an apertured casing and.a drum geared to the shaft 47 of the preselector mechanism so that when the knob 44 is turned to index the spools the drum is rotated to vary the indications seen in the window 61c of the casing. The upper end of the drum carries a head 66 having slots in which metal blocks 69, Fig. 9, may be secured. These bear numbers 1, 2 &c. and are positioned according to the required sequential speed changes for the particular job so'that the operator merely turns the indicator 44 to bring these blocks successively opposite an index mark to obtain the required speed changes. The drum carries indications of the spindle speed and also cutting speeds for various work diameters. The Specification as open to inspection under Sect. 91 describes also an indicating device wherein the drum indications seen through the window 61c give the correct tooling to be employed for hexagon and square turret faces, the feeds for each turret, the type of operation and the motor speed. The indicator thus constitutes a production log for the machine cycle. In another form, the drum indications comprise two columns corresponding with the two main motor speeds. The indicating lines on the head 66 have slots on either side and numbered blocks for the successive operations are positioned on one side or other of a line according to whether the high or low motor speed is required. This subject-matter does not appear in the Specification as accepted.