Patent GB-1381659-A (GB)
Title: Machining apparatus with automatic tool changing device
IPC: B23Q3/157
Filed: 1972-04-11
Abstract: 1381659 Tool changers TOYODA-KOKI KK 11 April 1972 16730/72 Heading B3B An apparatus for machining a workpiece comprises a bed 20; a column 24; a spindle head 25 movably mounted on the column; a spindle 26 for receiving a machining tool T1, T2; a tool storage magazine 33 independent of the spindle head means for selectively indexing a desired tool to a tool change position, i.e. at tool position T3; a carriage 71 movable on the column parallel to the spindle head movement; first power means, e.g. hydraulic ram 101, to move the carriage 71; intermediate transfer means 82 movably mounted on the carriage and adapted to hold a tool T2; second power means for moving the intermediate transfer means 82 between a first position near the spindle and a second position near the magazine; main transfer means 30 for transferring a tool between the spindle and the intermediate transfer means at the first position; first control means for controlling the operation of the first power means 101 such that the carriage 71 follows the movement of the spindle head 25; sub-transfer means 31 for transferring a tool between the intermediate transfer means at the second position and the tool change position on the magazine; and second control means for rendering inoperative the first control means such that the carriage 71 may be moved to a third position near the magazine tool change position to allow a transfer between the intermediate transfer means 82 at the second position and the storage magazine at the tool change position. The main transfer means 30 has an arm 43 with grippers at each end and can be parked at a horizontal position. The intermediate transfer means 82 includes a tool holder 90 which is rotated through 90 degrees before a transfer to the arm 43. The sub-transfer means 31 also rotates a tool through 90 degrees to align a tool with a receiving socket 150 on the magazine 33. The storage magazine 33 comprises a pair of chains passing round a rectangular path defined by corner drive sprockets and idler pulleys, The drive for the chains also rotates a coding drum (176) (Fig. 13, not shown), having a series of dogs (178) to actuate switches of a reading device to enable a required tool be located. The drum rotates once for a complete revolution of the chains carrying the tool sockets 150. Machine tool details.-The spindle head 25 is counterbalanced by a pressure ram 28 acting through a chain 27. The carriage 71 is guided on vertical shafts 70. A workpiece W is mounted on an indexable table 23 which is supported on superposed slides 21, 22. The various movements are actuated hydraulically through pistons driving rack and pinion drives, and by motor driven worm and wheel drives. The chain is indexed by a motor (164) (Fig. 15, not shown), driving through an override device (171), (172) to allow a plunger (192) (Fig. 14, not shown) to engage slot to fix the chain magazine in an indexed position. The carriage 71 follows the spindle head by a servo valve connection (Fig. 8, not shown), the valve (110) being operated by a solenoid (127) during a tool change to raise the carriage to the said third position at the top of the column 24.