Patent GB-850442-A (GB)
Title: Improvements relating to sewing machines
IPC: D05B73/00
Filed: 1958-06-19
Abstract: 850,442. Sewing machines. ANKER-PHOENIX N€HMASCHINEN A. G., [formerly PHOENIXN€HMASCHINEN A. G. BAER & REMPEL]. June 19. 1958 [June 19, 1957], No. 19709/58. Class 112 Rotary hooks, work supports, frames. In a flat bed sewing machine, Figs. 2, 4, 6, the support 32<SP>1</SP> for the bobbin case 7<SP>1</SP> in a rotary hook 7 is carried by a flap 32 which is pivoted at 33 to the machine frame and is also pivoted at 35<SP>1</SP> to a work-supporting plate 37 provided on its lower surface with slots 38<SP>1</SP> embracing a fixed pin 38. In operative position flap 32 and plate 37 are held at right angles to each other against the bias of a spring 35 by latch means, release of which allows the flap and plate to assume an aligned and inclined position abutting a fixed stop 36, for providing ready access to the support 32<SP>1</SP>. Rotary hook 7 is carried by a transverse shaft 6 driven by 2:1 gearing 5, 4 from a longitudinal shaft 2 driven by a belt 3<SP>1</SP> from the upper arm shaft. In a modification, Figs. 8, 9, 10, a free arm machine has a rotary hook 60, the support 96 for the bobbin case 60<SP>1</SP> of which is carried by a flap portion 99 of the free arm, said flap being hinged at 100 and being held in the operative position against the bias of a spring-loaded plunger (not shown) by latch means, release of which allows flap 99 to pivot downwardly for providing access to support 96. Rotary hook 60 is carried by a transverse shaft 59 driven by 1:1 gearing 57, 58 by a longitudinal shaft 56 which is driven by 2:1 gearing 55, 54 by a tubular longitudinal shaft 52, driven by a belt 53<SP>1</SP> from the upper arm shaft. Feed by dogs. An eccentric 9 on shaft 2 is embraced by a forked portion of a lever 11 which is pivoted at 14 to a crank 15 on a feed advance shaft 17, and is also pivoted at 12 to a block 13 slidable in a slot formed in a block 10. The latter is fast with a journalled shaft which carries a crank 22 connected by a link 21 to a pivoted handle 20, operation of which serves to rotate block 10 for varying the feed. The feed dog 8 is carried by a feed bar 19, one end of which is pivoted to a crank 18 on the feed advance shaft 17 and the other end of which is forked to embrace a pin 26 slidably mounted in one arm of a bell crank lever 25, the other arm of which is connected to the pitman of an eccentric (not shown) on shaft 2. An upstanding pin 31 on pin 26 lies in a slot 30<SP>11</SP> in a lever 30 connected by a link 29 to a crank 28 on a manually rotatable knob 27. If knob 27 is turned to position III lever 30 is swung against the bias of a spring 39 to withdraw pin 26 from bell crank lever 25 to allow the feed dog to be lowered to an inoperative position. When knob 27 is moved to position II pin 26 engages bar 25 for normal operation. If knob 27 is moved to position I lever 30 is moved against the bias of a spring 39<SP>1</SP> towards the rotary hook and out of engagement with an arm 34 fast with the pivot 33 of flap 32, whereby the latter is opened by spring 35. An eccentric 62 on shaft 52 is embraced by a forked portion of a lever 64 pivoted at 67 to a crank 68 on a feed advance shaft 71, and also pivoted at 65 to a block 66 slidable in a block 63 fast with a journalled shaft 63<SP>1</SP>. A crank 81 on the latter is connected by a link 80 to a pivoted handle 79 operation of which serves to vary the feed. The feed dog 61 is carried by a feed bar 76 pivoted at one end to a crank 73 on shaft 68 and also pivoted to an arm 72 journalled on a tapered pin 70 supporting one end of shaft 71. The other end of bar 76 carries a block 84 normally biased by a spring 85 into engagement with an eccentric 82 driven by shaft 52. Eccentric 82. which is integral with a cylindrical portion 82<SP>1</SP>, is slidable on shaft 52 and is fixed, by means of a transverse pin 95 passing through longitudinal slots 52<SP>1</SP> in shaft 52, to a rod 94 slidable in the latter. The outer end of rod 94 is connected by a slot 93<SP>1</SP> to a crank pin 92 fast with a manually rotatable knob 86. When the latter is in a central position eccentric 82 is situated under block 84 for normal operation. When knob 86 is turned clockwise, portion 82<SP>1</SP> is positioned under block 84 and the feed dog drops to an inoperative' position. When knob 86 is turned anti-clockwise, the transverse face of portion 82<SP>1</SP> engages a pin 108 on a spring-biased plunger 102, whereby a nose 101 of the latter is disengaged from a catch plate 104 on flap 99 to release the latter for movement to the open position.