GB1035894A - Centralized automatic control device in machines employed in manufacturing garments - Google Patents

Abstract

1, 035, 894. Sewing machines. VIRGINIO RIMOLDI & CO. S.p.A. Feb. 20, 1964 [Feb. 25, 1963], No. 7160/64. Heading D1G. Operating members of a sewing machine are electrically operated from a central control box containing relays, whereby operation of the machine is automatically effected by manual presentation thereto of a workpiece. A pair of bell crank levers P<SP>1</SP> and P<SP>2</SP> are pivoted to the head of a sewing machine one behind the other in the direction of work feed, and are so arranged that their lower limbs enter respective slots in the work-supporting plate. A work piece fed manually to the stitching point serves to raise the first lever P<SP>1</SP>, whereby its upper limb closes a microswitch 12 to start the machine. The work then raises the second lever P<SP>2</SP> to close a second microswitch 12 connected in parallel with the first microswitch 12. When the completed work allows the lever P<SP>2</SP> to fall and thereby open the second microswitch 12, the machine is stopped and a thread-cutting knife is automatically actuated. The control gear comprises relays 14,15, 16 and a step-down transformer 21 contained in a transparent box mounted on the sewing machine base. A pair of microswitches 23 are arranged to be held open by the tension in the respective threads, and a microswitch 24 is held closed by the retracted knife of solenoid-operated threadcutting means 24. Secondary current is supplied to the relay coils via the microswitches, and primary current, controlled by the relay contacts, operates the thread-cutter 24 and a magnetic starting-clutch 26. Closure of a microswitch 12 energizes relay 15, whereby contact 15c in the circuit of threadcutter 24 is opened, and contact 15a is closed to energize clutch 26 for starting the machine. Contact 15b is also closed to energize relay 16 via closed microswitch 24a, whereby contact 16b in the circuit of thread-cutter 24 is closed, and a holding contact associated with relay 16 is also closed. When the second microswitch 12 opens at the completion of the sewing operation, contact 15a opens to de-energize clutch 26 for stopping the machine, and contact 15c closes to energize threadcutter via closed contact 16b. Advance of the thread-cutting knife serves to open microswitch 24 for de-energizing relay 16 and thread-cutter 24 for retracting the knife. During normal operation, relay 14 is de-energized, whereby red warning lamp 17 is energized via contact 14b. On breakage of either thread the associated microswitch 23 closes to energize relay 14, whereby contact 14a in the circuits of thread-cutter 24 and clutch 26 is opened to immobilize the latter, and contact 14c closes to energize green lamp 18 and to establish a holding circuit for relay 14 via the push-button switch 20. Re-starting is thereby effected by actuating switch 20 to de-energize relay 14. The machine may also be stopped at any time by closing a switch 28 in parallel with a micro-switch 23. A lever 29 for actuating switch 28 is so arranged adjacent the needle, that switch 28 is automatically closed by the operator's fingers when the needle is re-threaded.