GB859981A - Improvements relating to zig-zag sewing machines - Google Patents

Abstract

859,981. Sewing machines. ANKER-PHOENIX NAHMASCHINEN A. G., [formerly PHOENIXNAHMASCHINEN AKTIENGESELLSCHAFT BAER & REMPEL]. May 9, 1958 [May 11,1957]. No. 14957/58. Class 112 In a zig-zag sewing machine comprising respective controlling means for the stitch width, stitch position and work feed, with respective manipulating means therefor, said controlling means can be coupled together and can be swung into a position such that, by the operation of one manipulating means only, the controlling means is brought as a unit into predetermined position for effecting e.g. the sewing of a buttonhole. As described, said controlling means comprise coaxial cams mounted within the machine frame. each of the cams having along one circumferential portion a profile to adapt the machine for normal sewing, and along another circumferential portion a profile to adapt the machine, when the cams are coupled together, for semi-automatic operation to effect buttonhole stitching under the control of one of said manipulating means. A plate 47, Figs. 4, 5, covering an aperture 50 in the frame 1 has fixed thereto a bush 93 which journals a hollow shaft 94 carrying at its inner end three cam discs 85, 86, 87 and at its outer end a disc 98. A shaft 96, journalled in shaft 94. carries at its inner end a cam disc 88 and at its outer end a handle 103. A handle 99, pivoted at 100 to disc 98, has an extension 102 ending in a nose 101 which is normally biased by a spring 123 into an annular groove 107 in handle 103.. The handle may therefore by moved independently of each other for normal stitching, cams 86 and 87 controlling the stitch width and cam 88 the stitch position, while a concentric portion on cam 85 renders the latter inoperative. A lever 44, pivoted at 46, has follower noses 112, 113 which co-operate with cams 87 and 86 respectively. A lever 52, also pivoted at 56, has follower noses 114, 115 which co-operate with cam 88. A lever 83, pivoted at 84, carries an adjustable follower stud 108 which co-operates with cam 85. For sewing buttonholes, handle 99 is pulled outwardly to disengage nose 101 from groove 107 and is turned through 180 degrees and released, when nose 101 will enter a recess 106 in handle 103 to couple the handles together. Operation of handle 99 then rotates all the cams simultaneously, cam 85 serving to control the work feed. Handle 99 is first engaged with a stop pin 111 for sewing the left hand side of the buttonhole with reversed feed, and is then moved to the upright position for sewing the bottom barring stitches with slow forward feed. Handle 99 is next engaged with a stop pin 110 for sewing the right hand side in forward feed, and is finally moved to the vertical position to sew the top barring stitches. A rotating cam 7, Figs. 1, 2, embraced by the forked end of a lever 8, is driven by gears 3, 4 from the machine arm shaft 2. The other end of lever 8 is pivoted at 9 to an arm 10 on the needle bar gate 11 mounted on horizontal pivots 12, 12<SP>1</SP>. Lever 8 is fulcrumed on a pin 14 carried by a block 15 slidable in a slot 16 in a member 17 pivoted to one arm 18. of a double-armed lever 18, 35 fulcrumed at 19. Pivotal movement of member 17 serves to vary the stitch width, and pivoting of lever 18, 35 serves to shift the stitch position. An arm 34 on member 17 is connected by a link 31 to one arm 20 of a double-armed lever fulcrumed at 19, and the other arm 20<SP>1</SP> is coupled by adjustably connected links 27, 41 to the cam follower lever 44. Arm 35 of lever 18, 35 is coupled by adjustably connected links 39, 40 to the cam follower lever 52. The feed dog 69, Figs. 1, 3, is carried by a feed bar 67, one end of which is forked to embrace an oscillating pin 68 on the feed lift shaft, and the other end is pivoted at 66 to a crank 65 on the feed advance shaft 64. A crank 63 on the latter is pivoted at 62 to one end of a lever 61 which is apertured to embrace a cam 60 on a rotary shaft 58. The other end of lever 61 is pivoted at 70 to a block 71 slidable in a slot 72 in a member 73 carried by a pivotally mounted pin 89. The angular position of slot 72 relatively to a line between pivots 62 and 70 will therefore determine the extent of oscillation of the feed advance shaft 64. A pin 75 on member 74 is biased by a spring 91 to the lower end of a slot 80 in one end of a link 76, the other end of which is pivoted to an arm 78 on a shaft 90 which carries a handle 77. Operation of the latter thereby normally serves to vary the work feed. When handles 99 and 103 are coupled together, a link 82 pivoted adjustably to follower lever 83 is then raised to bring the lower end of.a slot 81 therein into engagement with pin 75. Operation of handle 99 will then control the feed via cam 85 and link 82. In a modification, Fig. 15, a cam 142, carried by a shaft 146, is turned by a handle 152 to control the stitch position, a cam 143, carried by a hollow shaft 147, is turned by a handle 151 to control the stitch width, and a cam 144, carried by a hollow shaft 148 is turned by a handle 150 to control the work feed. During normal sewing the handles are turnable separately. For buttonhole sewing the handles are coupled together by a spring-biased plunger 153 and are then turned through 180 degrees.