GB1467239A - Tool selection structure and method of random tool selection - Google Patents

Abstract

1467239 Automatic control EX-CELL-O CORP 28 Feb 1974 [29 May 1973] 41029/73 Heading G3N A tool-changer employing a conveyer with toolholders for separate tools is associated with a random tool selection structure comprising a memory for storing tool code numbers, means associating each address in the memory with a tool-holder on the conveyer and means in response to a toolrequest for interrogating the memory and bringing the requested tool into an exchange position in a direction so that the distance the conveyer travels is a minimum. As shown, tools from a conveyer 130 are transferred by an exchange structure 57 to a machine tool 56. The conveyer is positioned by a drive 38 actuated over direction-determining lines 40, 42 from an auto-coincidence circuit 12. The position of the conveyer is sensed by a rotary switch 26 and fed, through an interface 24 to the circuit 12. During loading of the conveyer tool codes and corresponding tool-holder positions on the conveyer are manually set into a core memory 14 by thumbwheel logic 28. In automatic operation, a machine control unit 44 provides a tool word, for the tool to be placed into an exchange position 138, which is held in a register 20, and provides through a stroke unit 22 an indication to the circuit 12 that a new word is in register 20. The circuit 12 interrogates the memory 14 to cause a tool word, corresponding to the position of the conveyer as sensed by the switch 26, to be issued to coincidence logic 18. Lack of coincidence with the number in register 20 causes the circuit 12 to index the memory 14 until coincidence is attained. The circuit 12 then determines the required direction of travel and energizes the drive 38 accordingly. The tool number of the exchanged tool is temporarily held in a store 30 and the number of the returned tool transferred to a spindle store 32 and, subsequently, through logic 28 into the memory 14.