Patent GB-429875-A (GB)
Title: Improvements in and relating to embroidery and hemstitching machines
IPC: D05B19/00
Filed: 1934-10-08
Abstract: 429,875. Sewing-machines. ANCIENS ETABLISSEMENTS R. CORNELY & CIE, 87, Faubourg St.-Denis, Paris. Oct. 8, 1934, No. 28757. Convention date, Oct, 6, 1933. [Class 112] An embroidery and hemstitching machine has oscillating needles co-operating with rotating hooks to produce single and double " Turkish " and " river " hemstitching by the provision of driving cams of suitable profile and speed. The needles are oscillated symmetrically in known manner by links. The feed dog 18 is operated by the members 20, 21, 22, 23 and 86 for the vertical movements and by the cam 30 and levers 31, 32, 33, 87 for the longitudinal movement. In order to produce the double " Turkish " hemstitch shown in Fig. 8, the shaft 52 carrying the cams is driven at a speed eight times less than that of the main shaft 3 by gears 54, 56. The shape of the cams 20, 30, 42 produce movements of the feed, needles and hooks to produce the effect shown in Fig. 8 by an eight movement cycle. First, the needles penetrate the fabric close together at o-o, the longitudinal threads between the threads AA, BB, having been drawn. As soon as the needles have penetrated the fabric, they move from the lines EE, FF to the planes XX, YY, at the loop-taking point where the hooks 12 and 13 seize the needle loops. The needles then rise above the fabric which is fed in the direction indicated by the arrow F for a distance equal to 0-1. This corresponds to the phase 0-1 shown on the cam of Fig. 3. Second, with the needles again close together, they penetrate at 1-1 and at the loop-taking point move to position XX, YY and rise. The fabric is then fed backwards in the direction R for a distance 1-2, phase 1-2 on the cam 7, Fig. 3. Third, the needles, close together, penetrate at 2-2, go to the looptaking point and rise again. The fabric is fed in the direction F for a distance 2-3, phase 2-3 of the cam of Fig. 3. Fourth, the needles, still close together, penetrate at 3-3 and travel to the loop-taking point. The thread bar between 2-2 and 3-3 is then tightened by the thread which winds about it. The work is thus fed slightly in the direction R corresponding to the distance 3-1 and the projections 3-4 of the cam. The feeder then descends to release the work and rises to renew contact after having moved back a distance corresponding to half the distance d separating two thread bars, Fig. 8. Fifth, the separated needles penetrate at 4-4 on the lines CC, DD and move towards each other to arrive at XX and YY at the loop-taking point. After they rise, the work is fed in the direction F a distance equal to 4-5, phase 4-5 of the cam. Sixth, the needles penetrate at 5-5, arrive at the loop-taking point, rise, and the material is carried in the direction R for a distance equal to 5-6, corresponding to the phase 5-6 of the cam. Seventh, the needles penetrate at 6-6. The loop-taking point is at XX and YY. The needles rise and the material is carried in the direction F for a distance 6-7, phase 6-7 of Fig. 3. Eighth, the needles penetrate at 7-7. The looptaking point is at XX and YY. The thread bars held between 6 and 7 are tightened. The material is fed a short distance in the direction R corresponding to 7-8. The feeder then descends, releasing the work, and rises again to make contact with the work after having moved backwards equal to half the distance d, phase 7-8, Fig. 3. The same eight-movement cycle is then recommenced. By using different shaped cams, different forms of hemstitching such as shown in Figs. 7, 9 and 10 can be formed. The work may be held stretched by a circular member 77 surrounding the presser foot 76 and carried by a rod 75, Fig. 6.