Patent GB-1101014-A (GB)
Title: Machine tool with a tool changer
IPC: B23Q3/157
Filed: 1966-02-17
Abstract: 1,101,014. Tool-Changing. KEARNEY & TRECKER CORPORATION. 17 Feb., 1966 [1 March, 1965], No. 7100/66. Heading B3B. A machine tool comprises a tool storage magazine 55 having a " tool ready " 53 and a " tool restock " station 54 and a tool transfer means 56 for moving the previous tool from and the new tool to, the operating station 47. The spindle head 45 is moved by a recirculating ball screw-and-nut mechanism above cross-slides 38, 40. At preselected speeds, the transfer arm 56, Figs. 2 and 3, can be moved axially by a piston 177, it can be rotated by an hydraulic motor 185, and a pinion 225 thereon can be rotated by a second hydraulic motor 226 and a shaft 227 to advance jaws 61A, 61B and 62A, 62B. The jaws are moved into engagement with collars 132 on the tools by spring-actuated conical cam-pins 208 acting against balancing leafsprings 206, 206A. The magazine comprises a number of sockets 105, Fig. 10, linked by pins 107 to a chain 81 passing round four sprockets, two of which are carried on a plate 91, Fig. 9, adjustable for tensioning the chain. A further plate 97 is adjustable to tension the chain drive 101 to the chain 81 from an electric or reversible hydraulic motor 96. A valve (292) controls the motor speed. Each tool holder 48 is held in a socket 105 by a spring-pressed ball 134. Each socket is counted as it moves past a switch 137 and when a rod 146, projected from a holder when a tool 48 is inserted, actuates a switch 143, the motor 96 is stopped and an hydraulic plunger 157 is projected into a locating recess 159 to position the holder accurately. When a large tool such as 50C is used, adjacent holders are left empty. Overall control is by way of a punched tape and reader and a double-bank rotary stepping switch 420, Fig. 15, advanced by a spring returned pawl 443. The rotary switch is advanced to its initial contacts 406, 426 subsequently to moving the magazine to position a new tool. Three counters 461, 462, 463 are associated with the holder-counting switch 137. The counter 461 is operative only when the magazine is reversed for locating an empty holder at the restock station 54. The counter 463 is operative only in the forward direction. The counter 462 or " Minus-1 counter" is. operative after the first tool change cycle and serves as a memory. When the magazine is moved clockwise to position a new tool at the ready station 53 and an empty holder at the restock station 54, the switch 137 is actuated and a pulse transmitted to the operative counter 462. A single pulse is registered as zero and, consequently, there is no output to comparators 464 or 466. The circuit is then prepared for a signal from the record or a manual switch 396 to start a further tool change. When a large tool such as 50C is next to be used, during the clockwise magazine setting movement, the counter 462 successively registers " zero " and " one " as two holders pass the switch 137. A single pulse is thereby transmitted to the comparator 466. When the switch 143 is actuated by the rod 146 of the tool 50B, the plunger 157 is actuated and stops the magazine. When the tool 50B has been extracted, the motor 96 moves the magazine counter-clockwise, as soon as the plunger 157 is withdrawn, to position the correct holder at the re-stock station to receive the previous tool 50A. The movement causes the switch 137 to be actuated to send a pulse to the counter 461 so that it, and the counter 462, both have a count of " one " and the comparator 464 registers coincidence, although the comparator 466 is unbalanced. Relays 467 and 485 are thereby set to enable the tool change sequence to continue correctly. When the magazine is subsequently moved clockwise, the empty holder for the tool 50B actuates the switch 137 and transmits a pulse to the counter 463 to register a count of " one " and establish coincidence in the comparator 466. A mechanism 475 is provided to transmit a pulse to all the counters to reset them.