Patent GB-1088651-A (GB)
Title: Improvements in or relating to a method of and an apparatus for controlling an electromechanical element with on-off operation in accordance with a digital program in a machine having a variable operating speed
IPC: D04B15/78
Filed: 1965-02-02
Abstract: 1,088,651. Programmed control of textile processes. A. CORBAZ. Feb. 2, 1965 [Feb.4, 1964], No.4574/65. Heading G3N. In a machine an ON-OFF operating electromechanical element, having a fixed time constant, is controlled in accordance with a digital programme and arranged to operate at a rate which is proportional to the operating speed of the machine by generating a series of periodic electric pulse sequences of the same frequency but differing phases, and selecting one of the pulse sequences as a function of the operating speed of the machine and controlling the passage of actuating signals corresponding to pulses derived from the programme by means of the selected pulse sequence in such a manner that the signals are transmitted to the element when a pulse of the selected sequence is present and prolonged until the following pulse of the sequence occurs. As shown, control circuits 1, 2, 3 for the elements are identical and for circuit 1 the inputs comprise line 6, receiving pulses from a tape reader, not shown, responsive to a punched tape, and an auxiliary line 7 receiving pulses from a synchronizing circuit 4. The pulses on lines 6, 7 act on a NOR-logic element 8 and, with the pulses on line 6 fed through an inverser 11, on a NOR-logic element 10. The outputs of elements 8, 10 are fed to NOR-logic element 12, 13, interconnected to form a memory element, an output 16 being fed to an electromechanical device, Fig.5 (not shown), comprising a selector for a jack of a needle bed of a circular type knitting machine. The synchronizing circuit 4 has three input lines 20, 21, 22 having phased sequence pulses delivered thereto from a pulse generator comprising, Fig. 5 (not shown), a photo-electric device driven by the knitting machine, and two auxiliary input lines 35, 36, from a tachometric circuit 5 fed from line 22. The circuit 5 incorporates similar sub-circuits 51, 52, fed through a bi-stable multivibrator 48, of which sub-circuit 52 comprises a differentiating condenser 55 acting on a mono-stable multivibrator 56, and through an inverser 57 acting on a NOR-element 58 having its second input from the multivibrator 56. The output of multivibrator 56 is also fed through an inverser 59 to a NOR-element 60 having its second input from the inverser 57. The outputs of the NOR-elements 58, 60 are applied to push-pull interconnected NOR-elements 61, 62 from which the sub-circuit 52 output is derived from a line 65. An output is also derived on 67, 47 from the sub-circuit 51. The switching time of the multivibrator 56 is twice that of a similar multivibrator 69 in sub-circuit 51. The outputs on lines 65, 67 are applied to a NOR-element 66 and through an inverser 68 provides an output on line 46. The outputs 46, 47 are applied to NOR-elements 23-25 of the synchronizing circuit 4 together with the appropriate sequence pulses from lines 20-22. The outputs of NOR-elements 23-25 act through a NOR-element 37 on a mono-stable multivibrator 38 producing rectangular pulses which through an inverser 40 provides the synchronizing pulses for the control circuits 1-3. The Specification sets out the possible logic cases whereby one of the pulse sequences on lines 20-22 is selected in dependence on the machine range, determined by multivibrators 56, 69 and presented on lines N 1 , N 2 , and applied to the control circuits 20-22 so that the programme order is transmitted to the electromechanical element only when one of the selected pulses appears and is memorized until the appearance of the subsequent pulse. Further, when the programme order is changed it is only transmitted when the next selected pulse occurs.