Patent GB-190928830-A (GB)
Title: Improvements in Thread Buttons.
Inventor: LAULA HEINRICH
IPC: B65H81/02
Filed: 1909-12-09
Granted: 1910-12-01
Abstract: 28,830. Laula, H. Dec. 9. Button-covering machines.-A button is made by covering by sewing a metal or like ring. The ring is first covered by an overcasting stitch in which the needle thread b, Fig. 1, is pulled so tight that it passes, substantially without deviation from the circular, through the shuttle thread loops h, k, which are pulled right round the outside of the ring. The centre of the ring is filled in by a radial or chordal stitches b<1>, concentrated between the button blank and the ring of needle thread and then the overcasting stitches and cross - stitches are secured by a circular row of plain stitches b<2> on the inside of the ring. The centre can be ornamented or strengthened by varying the cross - stitches and by the addition of annular stitching as b<3>, Fig. 3. The whole process is carried out automatically in one machine. The ring or button blank is held on a button-feed disk 20, Fig. 11, between two toothed wheels 16 and a pressing-wheel 18, which may be rotated by an annular toothed wheel 25. When the ring is being overcast, the disk 20 is locked, and the ratchet-wheel 27 on the wheel 25 is rotated, thus rotating the button blank upon the disk 20. The sewing-threads at the beginning of the operation are secured in a clamp 51 or a disk 28, which is rotated in an opposite direction to the wheel 27 so as to have no movement relative to the button blank. During the overcasting, the needle-bar is vibrated laterally by a pitman which has been moved by a cam to engage with an active portion of a usual quadrant. At the completion of the covering - stitch, the pawls driving the wheels 27, 28 are removed, and the needle-vibrating pitman is moved to the part of the quadrant in line with its pivot. For the cross-stitching a pawl is put into operation which through gear-wheels rotates the buttonfeed disk 20. The needle does not vibrate, but between the stitches the button is rotated through a large angle. The last-mentioned actuating-pawl is withdrawn, and another pawl is brought into action which rotates the buttonfeed disk a small angle at a time for the annular locking-stitch. During the overcasting and the locking stitches the machine is driven at a high speed, and during the cross-stitching it is driven at a low speed. To obtain this, the machine is provided with a high-speed belt and a low-speed belt which are brought into use alternatively by a suitable cam. During the overcasting, the needle thread is put under a strong tension. Fig. 16 shows the tension device. Normally a light spring 115 only presses the disks together. A heavy spring 118 also presses upon the disks when during the overcasting a rod 121 is allowed to move to the left. For the overcasting-stitch it is necessary to pulloff a loop of shuttle thread for each alternate stitch. This is performed by a cam-actuated lever under the button plate, at a time the needle thread is held by a strong thread clamp. During the overcasting the presser-foot is lifted for alternate stitches and also given a slight oscillatory motion. When the overcasting is completed, the presser-foot is finally raised out of action. Most of the cams mounted upon the main cam-spindle operate their respective parts simultaneously, that is, at the changes from one form of stitching to another. At these times the speed of the cam-shaft is temporarily increased by the engagement of a fast-moving pawl with a suitably placed ratchet notch in an otherwise plain disk.