GB351677A - Improvements in and relating to buttonhole sewing machines - Google Patents

Abstract

351,677. Buttonhole sewing-machines. HUGHES, R. M., 72, Cannon Street, London.-(International Button Hole Sewing Machine Co. ; 502, Harrison Avenue, Boston, U.S.A.) May 20, 1930, No. 15458. [Class 112.] In machines for sewing " straight or " eyed '' buttonholes, the stitch-forming mechanism and work-holding means have a relative forward movement while stitching along the first side of the buttonhole, and at the " eye " end of the buttonhole, the stitch-forming mechanism is given a rotating movement to carry the stitching round the " eye." If a straight buttonhole is desired, the stitch-forming mechanism is rendered inoperative while passing round the eye. The stitching mechanism may be rendered inoperative after stitching along one side only of the buttonhole, to produce an " imitation " buttonhole. The work is supported in the usual clamp plates 8 and stitch-forming mechanism of the usual type with upper and lower threads is employed. The stitch-forming mechanism including the lower thread turret and needle bar 11 is arranged to be turned bodily about a vertical axis at each end of the buttonhole by a rock shaft 14 carrying a segmental gear 15 meshing with a gear 160. A cam rigid with the frame 13 provides for relative movement between the workholding means and stitch-forming mechanism during stitching along the sides of the buttonhole. The stitch-forming mechanism is driven from a shaft 18 by a loose pulley 19, clutched to the shaft or dog clutch 20. So long as the projection 23 engages the shoulder 24 on the pulley, the shaft and pulley are coupled. Release is effected by bringing a disengaging member 25 into the path of the tail 26. The member 25 is yielding supported on a rocking member 27 mounted on a rock shaft 28 supported on the frame 13 and having an arm 29. During stitching this member 27 is held in inoperative position by a latch 30 pivoted at 31 on the head 13 and adapted to engage a lug 32 carried by the arm 29. The latch 30 is disengaged from the lug 32 after the production of a single line of stitches to produce an " imitation " buttonhole by an arm 36 pivoted at 37 on a stand 38 on the bedplate, this arm being turned by the handle 39. Means are also provided for causing the clutch dog 20 to re-engage the shoulder 24 after the stitching mechanism has been swung round, to form a straight buttonhole. A portion 42 of the lever 36 has a dog 43 pivoted at 44 and having a finger 45 normally resting on the spring plate 46. The arm 29 carrying the projection 32 has a cam finger 47 with an inclined face 48. When the lever is swung out of position, the finger 45 and dog 43 are out of line. When the swinging lever 36 and carrier 52 are in the position shown in Fig. 5, the parts are in position for forming an " eyed " buttonhole.