Machine à coudre permettant de réaliser automatiquement des points formant des motifs divers

摘要

833,310. Sewing machines. MEFINA SA. May 2, 1958 [[May 9, 1957], No. 14079/58. Class 112 Needles, shifting laterally; work feeding. In a sewing machine having a control device adapted to act upon a needle bar, or upon a work-feed element, for producing a predetermined pattern of stitches, the control device comprises a digital programme controiler furnishing electrical signals, a series of electromagnets to which the signals are transmitted, a series of mobile abutments controlled by the electromagnets and each abutment being adapted to occupy a withdrawn position and a working position, a slidable control member connected mechanically to the needle bar or feed element, and driving means adapted to displace the control member in one or the other direction, the control member comprising arresting surfaces which co-operate with the abutments and are so arranged that each abutment determines two stopping positions of the control member depending on whether the latter engages an abutment when being displaced in one direction or the other. As shown, the swinging needle barcarrying gate 3 of a zig-zag sewing machine is connected by a link 5 to a slidable control member 6 adapted to be displaced in one direction or the other by electromagnets 8 and 9 respectively. The displacement is limited by rods 10, 11, 12 fast with the plungers of electromagnets 13, 14, 15, energization of which causes the respective rod to penetrate the respective one of a series of holes 16, 17, 18 of different diameters in the control member. Each rod when raised is adapted to stop the control member in two positions, depending on which direction the control member is displaced. The control member may therefore be stopped in eight different positions including the extreme left and right hand positions it can occupy when all the rods are withdrawn. The sequence of energization of the electromagnets is determined by a programme controller which comprises a ring 22 embracing an insulating disc 23 driven rotatably by the sewing machine. Mounted in the disc are five concentric rings of contact rods 24, the lower ends of which are respectively connected, via fixed contacts 26a to 26e, to the respective electromagnets. The lower end of ring 22 is connected, via a fixed contact 21, to a source of current 19, and the upper end engages a disc 25 formed with perforations 28 so arranged that some of the rods 24 are electrically connected to disc 25 while others are insulated therefrom. On rotation of the disc, current will pass to the electromagnets in a sequence determined by the perforations 28, the disc being interchangeable to provide various patterns of stitching.