Patent GB-1101831-A (GB)
Title: Improvements in or relating to machine tools
IPC: B23Q3/157
Filed: 1965-02-15
Abstract: 1,101,831. Tool-changing. GIDDINGS & LEWIS MACHINE TOOL CO. 15 Feb., 1965 [14 Feb., 1964], No. 6410/65. Headings B3B, B3C and B3K. A machine tool comprises a tool headstock 32 and a tool storage means 60 carried on vertical columns 34, 56 and movable in unison (by screws 106, 104), and a tool change means 66 mounted on the headstock. The tool spindle 38 can be advanced by a ram 52 and clamp in selected positions, the work then being fed to effect a cut. The tools are carried from the store to the change-arm by a shuttle 62. The store has two concentric rings 74, 76, Fig. 8, supported on balls 88, 94 running on twin-wire races 96. the rings are individually rotated by an hydraulic motor 114, Fig. 10, through worm and planetary gearing at a speed determined by a valve 126 in the return line. Each ring can be locked by a pivoted catch 170, 172, and can be slowed to a stop by a cam 180, 182. The cams 180, 182 each rotate once for every socket passing the transfer station and co-operate with a swinging lever 194 attached to a valve-operating rod 196 which can be latched by a fluid operated device 200. Tools are identified by cam stacks and magnetic read-out heads or by the socket number. When the required tool is approached on that matrix ring which is allowed to rotate by the latch 172 which is freed, the latch 200 is released to free the lever 194. As a roller 192 runs down the cam 182, the matrix ring slows down, the motor 114 begins to act as a pump and the latch 172 is then moved to lock a disc 164 and thereby the ring. Each tool is held in a matrix socket by a threaded stub 220, Fig. 8, which is rotated to grip a tool by spring-pressed rack-plungers and a gear 244 as the tool is moved into the socket. The tool is released by advancing a fluid pressure plunger 248. The shuttle 62, Fig. 5, is moved on rods 70 by an hydraulic motor 266 driving a screw 264 and carries a gripper slide 278 moved on rods 280, 282 by an hydraulic device 286. The shuttle is decelerated at each end of its stroke by a valve 274 brought into operation by a projection 322 on the shuttle moving a bar 308 axially, the bar having a cam portion 306. The gripper slide 278 has a pivoted jaw 336, Fig. 8, moved by springs (342) to grip a flange 330 on a tool and released by fluid means (340). Two balls (343) are attached to the jaw 336 and seat in a groove (344) in the face of the flange. When taking a tool from the inner ring 74, the slide 278 is moved axially of the tool and then raised before the shuttle is traversed towards the transfer arm. One tool is omitted from the outer ring 76 to provide access to the inner ring. Tool orientation is maintained so that driving dogs on the spindle may engage recesses 366 on the tool. The transfer arm 66, Fig. 23, has pivoted gripping fingers 361, 362 operated by springs 369 and opened by an hydraulic piston 370. The arm is moved axially by an hydraulic device 376 to withdraw it to a parked position. To engage a tool in, or withdraw it from, the spindle 38, the spindle is moved axially and a draw-bar 378 is actuated by an hydraulic motor 380. The arm 66 is rotated through 180 degrees to its operative positions by an hydraulic rotary motor 382 carrying a single vane 398 engaging vanes 396, 400 on a second hydraulic rotary motor 384. This latter motor is operated against the motor 382 to provide for a 30 degrees parking movement. Any looseness between the spindle 38 and the sleeve 40, through which it is rotated by a motor 406, is eliminated by a collet or spindle clamp. To position the spindle axially for boring and for tool exchange, a series of gauge rods 416 co-operating with a stop 418 are carried on a drum 410 indexed by a stepping motor 414.