Patent GB-390511-A (GB)
Title: Improvements in or relating to multiple lathes or the like
IPC: B23B9/02
Filed: 1931-10-05
Abstract: 390,511. Multiple spindle turretlathes. NEW BRITAIN GRIDLEYMACHINE CO., 140, Chestnut Street, New Britain, Connecticut, U.S.A.-(Assignees of Gridley, G. O. ; 22, West End Avenue, New Britain, Montgomery, D. H. ; 1, Hudson Street, Berlin, and Wheeler, E. H. ; 210, Farmington Avenue, Hartford, all in Connecticut, U.S.A.) Oct. 5, 1931, No. 27645. Convention date, July 16. [Class 83 (iii).] Chucks.-A multiple-spindle lathe has an indexable work-turret which is supported out of contact with its frame support during the indexing movement, means being provided to lock the work-turret to the frame between indexing movements by movement of the turret in a transverse direction. The gear-housing 2 and work-turret head 3 are connected by a tie-bar 4, which may support auxiliary slides or attachments. The work-turret, which is supported on the stem 98 having a flange at 157, carries a slotted plate 159 which coacts with a roll on an indexing arm 162 driven through spur gears 163 from an auxiliary cam shaft 140. A spring saddle 165 is mounted with rollers 167 bearing beneath the turret and located so that when the turret is unlocked, it is lifted just clear of spaced supporting abutments 169, and into contact with other rollers 170, 170<1>, so that during indexing the turret is supported entirely by these rollers to ensure free movement. When locked the turret is held down against the abutments 169. A locking-arm 174, held up by a spring 175 and engaging inset blocks in the turret, is cammed out of position during indexing by the surface 173 while a second locking-arm 176, positively withdrawn by a cam 180, tends in its locked position to force the turret downwards on to its supporting abutments. The Specification as open to inspection under Sect. 91 also describes an electric motor 5 which is connected by a chain 10 to a high speed countershaft 6 and to a central shaft 8, a jockey pulley being provided at 12. The shaft 8 is connected through back gearing to a shaft 13 which extends through the main tool slide support 98 and drives the work-spindles. The shaft 13 is also connected through worm gear 19, Fig. 4 (Cancelled), change gears 21, overrunning clutch 24, and sliding clutch 25, to a worm 23 driving the main cam shaft 27 at its low speed. The worm wheel 26 on the cam shaft is preferably so mounted that it may slip if excessive resistance is encountered. The high speed drive for the cam shaft is derived from the shaft 6 which is connected to the worm shaft 23 through clutch 28, bevel gearing 29, and spur gearing 32. The clutch 24 overruns so that the high speed is effective when both the high and low speed clutches are engaged. The high speed clutch 28 is normally automatically controlled while the low speed clutch 25 is moved manually by a clutch rod 33 operated from a handle 35. The clutch 28 is controlled by a rod 36 which crosses the clutch rod 33 and is interconnected therewith so that when the low speed clutch is disengaged the high speed clutch is also disengaged and is locked out of engagement. The disengagement of the low speed clutch also actuates a brake to assist in stopping the cam shafts. For hand operation of the cam shaft a shaft 44 is shifted to the right, Fig. 3 (Cancelled), to engage a wheel 45 with a wheel 31, but interlocking means are provided whereby the hand cranking mechanism and power feed cannot be operative at the same time. Means are also provided to stop the machine automatically at the end of an indexing operation if required. For this purpose an arm 48 may be shifted into the path of a cam lever 50 engageable with a cam 51 on the cam shaft 27 to throw out the clutch 25. A shaft 53, Fig. 6 (Cancelled), driven directly by the shaft 6 serves to drive cooling and lubricating pumps. The shaft 53 drives a pump shaft 56 and the base is provided with a cutting fluid reservoir 57 which feeds a centrifugal pump 58 discharging into a cored conduit 59 conducting oil to the tools and work. A second pump 60 draws oil from a reservoir 62 and discharges to the required points. Preferably a third pump fed from the pump 58 is arranged to supply cutting fluid at high pressure when required for example in deep-hole drilling. At the gear housing end of the machine are located four tool spindles 67 .. 70 corresponding to the four work spindles. These spindles may be employed for threading or other purposes and may be rotated from a gear 71 on the shaft 13 either directly or through an idler so that the spindles may be driven in either direction. An auxiliary cam shaft 75 driven by a chain from the main cam shaft carries cam drums 76, 77, either of which may carry dogs to actuate a clutch mechanism for a threading spindle. The upper cam shaft also actuates a work stop 84 by means of a cam acting through a rack lever. The stop may be actuated manually when required. The rotary tool-spindle 67 is carried in a slide 90 guided on a rod 91 and between guides 92, 4. The slide 90 is adjustably secured to a rod 93 secured to a slide 94 which is fed by a cam on the upper cam shaft. The tool-spindle 70 may be similarly fed but the lower tool-spindles are preferably fed by the main tool-slide 97 which is slidable on the stem 98 and is provided with slots to receive tool holders such as 101. The main tool-slide is fed bv cams 104 on the main cam shaft. Guide blocks 106, 109, Fig. 7 (Cancelled), coact with a depending arm 102 to prevent rotation of the tool-slide, the block 109 being adjustable. The direction of the cam pressure is such that all the wear normally occurs on the adjustable block. Cross-slides are preferably provided for each spindle, the guides for these slides comprising substantially cylindrical studs 116 bearing in the frame. The lower cross-slides are split to fit over the studs, the splits having interposed stems and being held together by bolts 121. To prevent rotation, the lower slides have upstanding arms 122 guided between spaced wear blocks 124. Interchangeable tool-holding plates 126 are carried on the slides and the end of the bore in each slide is closed by a plate 128. Thus on the forward stroke of the slide a partial vacuum is produced behind the plate 128 which tends to prevent overrunning, while on the return stroke a cushioning effect is obtained. Oil grooves in the studs communicate by a pipe 130 with an oil mist above a reservoir so that on the forward movement of the slide, oil is sucked into the slide cylinder to give continuous lubrication of the slides. The upper tool-slides which are lubricated in a similar manner may be both mounted on a single stud 131 and have depending arms guided between the blocks 124 to prevent rotation. The cross-slides are all operated by levers pivoted on studs 147, and actuated by front and rear auxiliary cam shafts 137, 140 driven by gearing from the main cam shaft. The withdrawal of the cross-slides is positively effected to clear the tools for indexing. Each of the work-spindles 158 is provided with a gear engaging a central gear on the shaft 13 and is carried on preloaded ball bearings, Fig. 13 (Cancelled), separated by inner and outer spacers 193, 187 which may be of slightly different lengths to preload the bearings. When a smaller spindle is required such a spindle is fitted with ball bearings of larger size and the use of liners or adapters may be dispensed with. The spindle nose has inclined ways 197 operating collet jaws 198, the collet being drawn rearwardly to close the chuck by a sliding sleeve 209, movement of which forces balls 208 inwardly between a fixed collar 202 and a collar 203 secured to the collet tube. The stock is fed by feed fingers 213 carried by a feed tube 214 which is supported in a roller bearing 215 and is operated by a shoe carried by a feed slide 216 guided in bars 217, 218. The feed shoe may be drawn out of the spool to remove a spindle for repairs. The feed slide is moved in the feed direction by a spring under the control of the feed cam 225 on one of the auxiliary cam shafts. Automatic means are provided for latching the feed shoe in withdrawn position and for causing it to re-engage the feed tube spool correctly. The chucking sleeve is actuated by a fork 210 slidable on a stud 227 and having a finger engaged by a slotted shoe carried by a chucking slide 230 actuated by cams on the auxiliary cam shaft 137. The feed tube spools which are not in engagement with the feed shoe are held rearwardly by an adjustable track 235 and the guide fingers of the chucking slide when not in engagement with the chucking shoe are held in chucked position by a fixed track 236. The chucking slide may be actuated by hand from a shaft 239. The stock reel 240, Fig. 15 (Cancelled), supported on rollers on a standard 241, is connected to the turret by a tube 243 which also supports a spider 246 having roller bearings for the stock tubes. By this construction the stock reel is positively rotated with the turret. In order to convert the machine into a chucking lathe means are provided to stop one spindle at a loading position after each indexing, fluid pressure being employed for chucking and for actuating the spindle clutch. The chucking spindles 250 are supported on ball bearings, Fig. 18 (Cancelled), similarly to the screw machine spindles and are driven from a central gear 183 through a clutch comprising a splined positive clutch sleeve 255 which is engaged only after the spindle has been speeded up by a friction clutch 264. The sleeve 255 is splined to an abutment sleeve 258 and is actuated bv a fork 261. A second abutment sleeve 263 is movable to the right in Fig. 18 (Cancelled) to engage the friction clutch and rotate the spindle. This clutch is actuated by means of balls 265 which are moved radially inwards by movement of the sleeve 255 to the right. When the spindle has been speeded up by the friction clutch, further movement of the sleeve 255 engages the positive clutch after which the balls may move outw