Patent GB-191119295-A (GB)
Title: Button Hole Attachment for Sewing Machines.
Inventor: BOYLER EMANUEL JOHN
IPC: D05B3/24
Filed: 1911-08-29
Granted: 1911-12-21
Abstract: 19,295. Boyler, E. J., Greist, P. R., and Greist, H. N. Aug. 29. Sewing- machines; buttonholing - attachments. - The work is held upon the underside of a clamp-plate 46 by a spring-clip 48, and is engaged by teeth 47 formed about the edges of a rectangular slot in the clamp-plate. The clamp-plate is secured to a rack-plate 45 having a sliding - rocking connexion with a vibrating- plate 43 which is pivoted at 44 to the stationary frame of the attachment. A pin 54 on the rack-plate enters a cam-slot in the vibrating plate which comprises two straight portions 52 joined by a semicircular portion 53. The vibrating-plate is vibrated by a lever 41, a screw 59 on which engages near the end of its movement with a pin 60 on the vibrating- plate. A ratchet-wheel 64 is carried by the vibrating-plate and is intermittently rotated by engagement with a stationary pawl 65. A pinion, rotating with the ratchet-wheel, engages with the teeth on the rack-plate and imparts to it a step-bystep feeding movement. At the completion of one side of a buttonhole, the pin 54 reaches the end of the first straight portion 52 of the cam slot and the pinion, engaging with a curved portion 57 of the toothed rack, commences to turn the rackplate. This movement is continued manually by the operator until teeth 55 on the opposite edge of the rach-plate engage with the pinion, which then commences the feed for the second side of the buttonhole. To obtain barring stitches, a barring-plate 76 carried by the vibrating-plate is moved to press upon the tail 79 of the pawl 65 and move the pawl out of engagement with the ratchet-wheel. This movement also wedges the cam-edge 11 of the barring-plate against the lever 41 and, thereby, the whole of the movement of the lever is transmitted to the vibrating-plate. The lever 41 is linked to a slide 35 which is moved to-and-fro as follows:-The needle-bar oscillates a lever 20 pivoted to a bracket on the stationary frame, and the motion is transmitted by a pin-and-slot connexion to a leverplate 23 pivoted to a second bracket on the frame. A pawl 31 on the plate 23 engages the shoulders of the parts 29 and the notches 30 of a cam-disk and rotates it. The cam-disk has an odd number of high points 29 and is engaged by lugs 27 on a plate 26 sliding between guiding flanges 25 on the lever-plate 23. Thereby, the flanges 27 are moved, alternately, into engagement with the edges 36, 37 of the slide 35 and impart to it a single movement for each complete reciprocation of the needle - bar. The bracket carrying the lever 20 is secured to the presser-bar for the support of the whole attachment. This bracket is secured to the main-plate 15 by a screw 16 and can be adjusted relative to it by a screw 91 which engages with the bracket supporting the lever plate 23. This adjustment moves the attachment relative to the stitching point and so alters the width of the buttonhole. The number of stitches to the inch is varied by means of a stitch-regulating anchor 68, which may engage with one or other of two edges 71, 75 on the feed pawl 65. A spring- controlled plate is attached to the rack-plate 45 to ensure its engagement with the feed-pinion. The length of the buttonhole is determined by the initial position of the rack-plate which is graduated to indicate the initial positions for various sizes of buttonhole. A feed cover-plate is used to mask the usual feed-dog of the sewing-machine. If desired the spring-clip 48 may be dispensed with and the teeth 47 be relied on to move the fabric over the feed cover-plate. In a modification, Fig. 24, the pin 60 is carried by a plate 92 sliding upon the vibrating-plate, and it is moved into contact with the screw 59, to increase the throw of the plate for the barring stitches, by the engagement of a pin upon it with a cam-slot in a plate 97, also sliding upon the vibrating-plate. The plate 97 is connected by a pin-and-slot which permits some lost motion with a third sliding plate which is used to remove the feed pawl from engagement with the ratchet-wheel. The stitch-regulating anchor engages with steps on the plate 97.