Patent GB-1109104-A (GB)
Title: Control system for sewing machines
Inventor: COHEN SAUL MEYER
IPC: D05B69/20
Filed: 1965-10-04
Abstract: 1,109,104. Electronic counters. CLINTON INDUSTRIES Inc. 4 Oct., 1965, No. 42052/65. Heading G4A. [Also in Divisions D1 and H2] In sewing apparatus an electric pulse is produced for each stitch-forming cycle, the pulses actuate a binary counter, and after a predetermined number of pulses, as determined by the setting of ganged rotary switches, the winding of an A.C. driving motor is disconnected, and a charged capacitor is connected across the winding to stop the motor. A sewing machine 10 is driven by an A.C. motor M having a running winding W and a starting winding W1 shunted by a capacitor C13. A cam 13 is adapted to close a switch S1 for each stitch-forming cycle. Closure of a main switch 25 in A.C. lines X, Y serves to energize a capacitor C11 via a diode D12 and a normally-closed switch contact 2RC1 of a relay 2RL, and also, via a transformer T, to energize a rectifier DR having its.negative terminal connected to a line A and its positive terminal earthed. Line A is connected respectively to the following power terminals: PS3 of a pulseshaping circuit PS; 1FF5, 2FF5, 3FF5, 4FF5 of bi-stable flip-flop circuits 1FF, 2FF, 3FF, 4FF; and FS2 of a control circuit FS. The input terminal PS2 of circuit PS is earthed via switch S1. The output terminal PS4 of circut PS is connected to the input terminal 1FF1 of circuit 1FF, the output terminal 1FF2 of which is connected to the input terminal 2FF1 of circuit 2FF, and via a diode D8 to certain of the fixed contacts of a rotary switch 1RS. The output terminal 2FF2 of circuit 2FF is connected to the input terminal 3FF1 of circuit 3FF, and via a diode D9 to certain of the fixed contacts of a rotary switch 2RS. The output terminal 3FF2 of circuit 3FF is connected to the input terminal 4FF1 of circuit 4FF, and via a diode D10 to cerrain of the fixed contacts of a rotary switch 3RS. The output terminal 4FF2 of circuit 4FF is connected via a diode D11 to certain of the fixed contacts of a rotary switch 4RS. The switches RS are ganged and their movable arms are connected to the input terminal FS1 of circuit FS, and via a resistor R23 to line A. The arrangement is such that each time switch S1 closes for earthing terminal PS2, a positive. pulse of uniform intensity and duration is applied to terminal 1FF1. The circuits FF are so arranged that their output terminals change from positive to negative and vice versa on the application of successive positive pulses to their input terminals. Circuit FS is so arranged that a negative pulse applied to its input terminal FS1 serves to activate circuit FS, whereby a relay 3RL is energized via the output terminals FS3, FS5 of circuit FS, said negative pulse occurring only when negative pulses are applied to all the switches RS which are connected in circuit. The connections to the fixed contacts of the switches RS are so arranged that the successive positioning of the movable arms from the contacts 2 to the contacts 12 require successively 3 to 13 positive pulses applied to terminal 1FF1 to actuate circuit FS, the contact 1 requiring 14 pulses. To initiate sewing, a switch S3 is closed momentarily to energize a relay 1RL for opening switch contacts 1RC1, 1RC2 and closing contacts 1RO1, 1RO2. Motor winding W is then energized via contact 1RO1, and relay 1RL is held via contact 1RO2. After the predetermined number of pulses has been applied to terminal 1FF1 for actuating circuit FS, relay 3RL is energized to open contacts 3RC1 3RC2, 3RC3 and to close contacts 3RO1, 3RO2, 3RO3. Opening contact 3RC3 deenergizes relay 1RL to close contacts 1RC1, 1RC2. Motor winding W is thereby deenergized, and relay 2RL is energized via contacts lRC2, 3RO3 to open a contact 2RC1 and close a contact 2RO1, whereby capacitor C11 discharges through winding W 1  via contacts 1RC1, 2RO1 to stop the motor M and sewing machine 10. Cam 11 is so arranged that the needle stops either in the fully-raised or in the fully-lowered position. Closing of contact 3RO2 applies a negative pulse to the re-set terminals 1FF3, 2FF3, 3FF3, 4FF3 of the circuits FF to return the latter to their original condition. Closing of contact 3RO1 connects the re-set terminal FS3 of circuit FS and an earthed capacitor C10 to line A via a rheostat R28, whereby circuit FS is restored to its original condition, for de-energizing relay 3RL, upon charging of capacitor C10, the charging time being determined by the setting of rheostat R28.