Patent GB-870400-A (GB)
Title: Improvements in or relating to sewing machines
IPC: D05B29/06
Filed: 1958-09-18
Abstract: 870,400. Sewing machines. UNION SPECIAL MACHINE CO. Sept. 18, 1958 [Oct. 2, 1957], No. 29846/58. Class 112 Multi-needle machines, stitch-forming devices, frames. A sewing machine adapted to produce simultaneously a seam adjacent the edge of work and an overedge seam enclosing said edge comprises a base provided with a horizontal work-supporting surface, a rotary drive shaft mounted in said base, an auxiliary housing mounted on said base and communicating therewith, a plurality of reciprocatory shafts mounted in said housing and each carrying a stitchforming element, and connections between said driving shaft and said reciprocatory shafts for reciprocating the latter, said connections comprising a member arranged for rocking movement about a vertical axis for reciprocating one of said reciprocatory shafts. The machine base 10 carries a cloth plate 11 and journals a driving shaft 15. A lever 18 journalled at 19 in the upper arm 13 is connected at one end by a pitman 17 to a crank pin on shaft 15, and is connected at the other end by a link 20 to the needle bar 22 which carries needles 23 and 24. Needle 23 co-operates with a threadedlooper 25 to form a line of double-loop stitches inwardly of the work edge, and needle 24 cooperates with a threaded underlooper 36 and an unthreaded overedge looper 48 to enclose the work edge. A threaded looper may be substituted for the looper 48 to form a three-thread overedge seam. Looper 25 is mounted on a carriage 26 pivoted at 27 on a sleeve 28 secured to a rock shaft 28a. Carriage 26 is connected by a link 29 to one arm 30 of a lever pivoted at 31, the other arm 32 being connected by a pitman 33 to a crank pin on shaft 15, for imparting loop seizing and shedding movements to the looper. An arm 34 projecting from shaft 28a is connected by a pitman to an eccentric on shaft 15 for rocking shaft 28a to impart needle-avoiding movements to the looper. Looper 36 is secured to one end of an inclined shaft 37 slidable in a bearing 38 fixed in a wall of an auxiliary housing 39 which is secured to the upper surface of base 10 and is closed by a cover 40. The other end of shaft 37 is connected by a link 41 to one arm 42 of a lever pivoted at 43 in housing 39, the other arm 46 being connected by a pitman 47 to a crank pin on shaft 15, to impart reciprocatory movements to shaft 37. The looper 48 is secured detachably to one end of a horizontal shaft 49 journalled in a bearing 54 fixed in the wall of housing 39. A lug carried by shaft 49 has in a helical slot 53 formed in bearing 54, whereby reciprocation of shaft 49 is accompanied by oscillation thereof. A vertical shaft 62a, fixed in housing 3a, journals a sleeve 62. An arm 60 projecting from the upper end of sleeve 62 has a forked end 61 which embraces shaft 49 and is disposed between fixed abutments 58, 59 on the latter. An arm 63 projecting from the lower end of sleeve 62 is connected by a pitman 64 to a crank pin 65 on shaft 15, to impart reciprocatory movements to shaft 49. Thread 67 for needle 23 passes to the latter via a tensioner 71, a fixed guide 72, a guide 73 mounted on lever 18, and a guide 74 mounted on the needle bar 22. Thread 68 for needle 24 passes to the latter via the tensioner 71, a fixed guide 72a, a guide 75 carried on lever 18, and a fixed guide 76. Thread for looper 25 passes thereto via the tensioner 71, a fixed guide 77, and a rotary takeup 78. Thread for looper 36 passes thereto via the tensioner 71, the fixed guide 77, a fixed guide 79, a guide 80 carried by the lever arm 30, and a fixed guide 81. Feed by dogs. A feed dog 82 is carried at one end of a bar 83 the other end of which is pivoted to the upper end of an arm 84 pivoted at its lower end on a fixed pin 85. A link 87 pivoted at one end on a pin 86 projecting from arm 84, is connected at its other end by a pitman 88 to a crank pin on shaft 15, for imparting feed advance movements to dog 82. Said crank pin is adjustable radially of the axis of shaft 15 to vary the feed stroke. An arm 91 depending from bar 83 is connected by a pitman 92 to an eccentric 93 on shaft 15, to impart vertical movements to the feed dog. Trimming. The edge of the work is trimmed in advance of the needles by a stationary blade 101 co-operating with a movable blade 125. Blade 102 is clamped in adjusted position in an upwardly inclined channel formed in a support 102. Carried by a block 105. A screw 106 passing through a slot 107 in block 105 and entering a tapped hole in a fixed plate 11a supporting the cloth plate 11, clamps block 105 in adjusted position. A forked member 109, depending from plate 11a, embraces a grooved portion 110a of a screw element 110 whereby turning of the latter, after slackening screw 106, effects adjustment of blade 101 transverse to the line of sewing. Blade 125 is mounted on a rock frame 111 pivoted on an eccentric portion of a pin 115 secured in the wall of housing 39. Blade 125 is clamped in an inclined channel formed in a carrier 122 which is slidably mounted on a block 118 and is clamped in adjusted position thereon. Block 118 is fixed to a shaft 117 slidable in spaced lugs extending from a head 116 of frame 111. A spring 120 biases shaft 117 to the left, when a projection 119 from block 118 overlies one of said lugs to maintain blade 125 in operative position. Block 118 may be moved to the right to align projection 119 with a channel 121 in head 116, when block 118 may be tilted to raise blade 125 for providing access to the loopers. A guard 132 is provided to discharge the trimmings forwardly and downwardly. Lubrication. Parts within the enclosed portion of the frame are lubricated by mist created by the action if certain parts of the mechanism on the body of lubricant provided in a reservoir at the base of the frame. Parts outside the enclosed portion are lubricated by tubes and wicks. The machine stands in an oil pan, and means are provided for returning lubricant collecting in the latter to said reservoir. For this purpose a gear-type oil pump 133 is secured by screws 134 inside the base 10 and is driven by gears 140, 141 from shaft 15. A suction pipe 146 extends from pump 133 to an opening in a plug 149 fitted in the bottom of base 10. Lubricant is discharged through an opening 153 in the upper surface of the pump casing. Oil guards such as 154 and 155 are provided for preventing discharge of lubricant collected from the mist through various openings in the walls of the casing. Specifications 779,132 and 779,133 are referred to.