| 摘要 |
933,923. Programme controlled jig-borers. FOSDICK MACHINE TOOL CO. Jan. 13, 1960 [Jan. 13, 1959], No. 1268/60. Drawings to Specification. Class 38 (6). [Also in Group XXII] The co-ordinate movements of the worktable and the tool spindle speed and feed-rate of a programme controlled jig-borer are read serially from the punched programme tape and temporarily stored in a cross-bar switch before being used to control the jig-borer disclosed in Specification 831,654, substantially in the manner disclosed in Specification 893,795. The tape, Fig. 4 (not shown), has eight hole positions across its width used for the four numbers 1, 2, 4 and 8 the remaining numbers being obtained by a parallel combination of these holes, and for four code letters. The letters are used to identify the X and Y coordinate commands, to indicate the necessity for a tool change, and to indicate the end of a block of information. In sequence, the first three numbers define the serial number of the machining operation, two sets of six numbers define the X and Y co-ordinates to one tenthousandth of an inch and two set of three numbers define the speed and feed rates. The tape reader has contact pins which control relay trees which convert the 1, 2, 4, 8 code into nine decimal lines which can energize the appropriate horizontal select solenoid of the cross-bar switch. A multi-bank stepping switch clears the previously stored information and applies the output of the reader and decoder in sequence to successive vertical hold solenoids of the cross-bar switch until all the required 18 digits have been stored. The code letters selectively energize relays which prepare circuits so that the stored information can be routed to the appropriate control circuits. The X and Y co-ordinates are controlled substantially as in Specification 893,795 in which gauges are stored in turrets which are stepped to a contact marked by the programme and the feed rate and spindle speeds are controlled by selected electromagnetic clutches in change-speed gear-boxes. Provision is made for parity checking the programme tape, changeover to manual control, and a large number of indicator lamps. |
