GB1026538A - Apparatus for the automatic control of sewing machines - Google Patents

Abstract

1,026,538. Programmed control of sewing machines. DURKOPPWERKE A.G. Aug.14, 1962 No.31131/62. Heading G3N. [Also in Division D1] A buttonhole sewing machine 2 is mounted on a carriage 22 which is supported by wheels 23, 23<SP>1</SP> on rails 24, 24<SP>1</SP> and is adapted to be driven therealong by a motor 1. The sewing machine thereby moves relative to a fixed table 28 carrying a workpiece 29, and the arrangement is such that the machine sews a succession of buttonholes L1, L2 &c. the distance between the edge of the workpeice and the first buttonhole, and the spacings between the buttonholes being predetermined and adjustable. A disc 3, rotatable with the wheels 23<SP>1</SP>, is formed at is periphery with a circle of holes 27. A photo-electric cell 5 on carriage 22 is so arranged as to receive light successively through the holes 27, on movement of the carriage 22, from a lamp 4 also mounted on the latter. Cell 5 is connected to electronic counting tubes 30, 31, 32 registering respectively units, tens and hundreds. Potentiometers 48, 47, 46, each having ten tappings connected to contacts engagable by pivoted blades 86, 85, 84 respectively, are connected to the respective tubes 30, 31, 32. By suitably adjusting the position of the blades, the tubes can be made to register initially any number short of a thousand. The tubes on receiving a complementary number of impulses from cell 5 then return to zero and a switch 58 closes. Each impulse corresponds to an advance by carriage 22 of 1 mm. Stepping of the blades is effected by energization of respective solenoids 90, 91, 92. A programme disc 36, rotated by a motor 34, is formed with five concentric circles 37, 38, 39, 40, 41 of holes, each of which can receive a cam member 42. The cams in the respective circles 37, 38, 39 are adapted to close respective micro-switches 43, 44, 45 for energizing the solenoids 87, 88, 89 respectively. Cams in circle 40, equal in number to the number of,buttonholes, are adapted to close a switch 49 to energize a solenoid 50 for stopping motor 34. A single cam in circle 41 is adapted, at the end of a rotation of disc 36, to close a switch 60 to energize a solenoid 61 for tilting a pair of mercury switches 62 and 65. Operation is initiated by momentarily depressing a starting switch 82, whereby a triode valve 79 is activated to effect switching off of lamp 4 and the starting of motor 1 to traverse carriage 22. Motor 34 is also started to rotate disc 36 until it is stopped by the actuation of switch 49, when the arms 84, 85, 86 have been stepped to the extent corresponding to the distance required between the edge of the workpiece and the first buttonhole. A beam of light from a lamp 12, carried by the sewing machine, is reflected from a surface adjacent the stitching point on to a photo-electric cell 13 also carried by the sewing machine. When said beam is interrupted by the edge of the workpiece, valve 79 is de-activated and lamp 4 is illuminated to impress the complementary number of impulses on the tubes 30, 31, 32 to effect closure of switch 58. Thereby motor 1 is stopped, machine 2 is started to commence sewing of the first buttonhole, and motor 34 is started to set the arms 84, 85, 86 corresponding to the distance between the first and second buttonholes. On completion of the buttonhole, a lever 63 of the sewing machine allows a switch 64 to close for starting motor 1, whereby carriage 22 travels until cell 5 applies the complementary number of impulses. Closure of switch 60 on completion of a revolution of disc 36 serves to return the carriage 22 to its initial position after completion of the last buttonhole.