Patent GB-946154-A (GB)
Title: Multiple spindle tool changer
IPC: B23Q3/157
Filed: 1961-08-01
Abstract: 946,154. Drilling; chucks; machine-tool details. KEARNEY & TRECKER CORPORATION. Aug. 1, 1961 [March 14, 1961], No. 27832/61. Headings B3B and B3C. A machine tool comprises a plurality of toolholders 112 in a tool head 27 and a multiple toolchanger 63 operable to insert a plurality of tools 114 into the holders. The head 27 is traversed at variable speed rates by a motor 28 driving a screw through a clutch. The spindles are supported by adjustable arms 36-45 and are rotated by a motor 54 through a clutch, variable-speed gear and flexible shafts 105. Sets of tools are carried in a turret 58, the faces of which carry tool-retaining recesses 59 each set in an identical arrangement, into which arrangement the toolspindles must be moved before a tool transfer can take place. The changer 63 comprises a slide 86 movable transversely by an hydraulic device 69 and having tool grips positioned, in the same arrangement as the recesses 59, on a slide 90 movable axially by an hydraulic device 92, each tool being transferred always to-and-from its own socket in the turret. Each tool has, or is, fixed in a tool-holder having a cylindrical shank 114. The shank 114 is gripped by a spring collet 112 closed by an axially movable friction ring 117. Each spindle support arm such as 36, Fig. 3, is clamped in an adjusted position by a pivot clamp 125 and a movable clamp 144. The clamp 125 is actuated by springs 132 and released by fluid pressure means 139. The clamp 144 is similarly actuated by springs, acting through a bridge piece 160 and released by fluid pressure means 171 which move only so far as to leave a frictional hold on the arm 36. The bridge piece 160 also serves to operate the clamps for the arms 37, 45. Similar clamps are provided for the arms along each side of the head 27. The fluid-pressure clamping means are controlled by solenoids operable singly or in unison. The arms and tools may be positioned by a template or automatically by means as described in Specification 931,276. The tools are held on the slide 90 by devices 62 actuated by hydraulically-operated sleeves 197, 198 and a piston 194 to give three positions of a rod 196. The devices 62 include a slotted sleeve 228 moved by the rod 196 to engage and pivot levers 216. In operation, as the slide 90 is moved to pick up tools, a collet 253, Fig. 6, is urged by a spring 260 to engage a groove 267 in a tool shank 114, the ends of the levers 216 engage and move the ring 117 to release the tool, and spring fingers 212, 213 engage grooves 270, 271 in the collet 253. As the withdrawal movement takes place, the levers 216 are held inwardly to cause pins 223 thereon to engage the fingers 212 and lock the tool in the device 62. All the tools are thus withdrawn from the spindles and are moved rearwardly, transversely and forwardly back to their sockets in the turret where they are retained by spring-pressed detents. When the devices 62 have each been moved to insert a new tool in a spindle, the ring 117 is moved forwardly by notches 295 in the levers 216 while the tool is held steady by the collet 253 and the spring 260. The two positions of the slide 86 are determined precisely by hydraulic plungers thereon which engage bevelled recesses in the machine base. The turret 58 is similarly positioned by a plunger on the frame and is indexed through one or more stations by hydraulicallyoperated ratchet gearing. A complete toolchanging sequence is controlled automatically by a seven-arm stepping switch which is stepped by a solenoid actuated when all the limit switches in a completed step have been actuated. Specification 942,040 also is referred to.