Patent GB-917060-A (GB)
Title: Overedge sewing machines
Inventor: SIGODA VICTOR JOSEPH
IPC: D05B1/20
Filed: 1961-11-17
Abstract: 917,060. Sewing; sewing-machines. MAN-SEW CORPORATION. Nov. 17, 1961, No. 41215/61. Class 112. An overedge sewing-machine comprises a threaded underlooper arranged to move in the line of stitching, a spreader member arranged to seize the underlooper thread and to convey a loop thereof to a point beyond the edge of the work, and means for intercepting said loop and for carrying a thread loop upwardly and across the surface of the work into the path of reciprocation of the needle. The arrangement as shown consists of a modification of a known machine in which a pair of needles 11, 12 cooperate with a pair of threaded underloopers 21, 22 swinging in the line of stitching and a pair of loop-spreading fingers 25, 26 carried by a laterally reciprocating bar 28, to form two parallel lines of two-thread chain stitching. The modification consists in increasing the lateral movement of at least the inner spreader 26 to carry the loop taken from looper 22 beyond the edge of the work, and the provision of vertically-moving threaded looper 104 and a threaded upper looper 91 which moves laterally above the work. The arrangement produces the stitching shown in Figs. 18 and 20, 165 and 166 being the threads from the needle 11 and looper 21 forming two-thread chain-stitching, and 168, 169, 170, 171 being the threads from the needle 12, underlooper 22, vertical looper 170 and upper looper 171 forming a four-thread overedge seam. Fig. 21 shows an arrangement in which spreader 25 is given sufficient lateral movement to concatenate the thread 166 with the overedge seam. Looper 91 may be unthreaded for producing a three-thread overedge seam, and loopers 91 and 104 may be unthreaded for producing a twothread overedge seam. The machine is arranged for needle feed, the needle bar 10 being slidably journalled in a bracket 35 rigid with a shaft 32 oscillated via an arm 31 from a variable eccentric 29 on the upper arm shaft 6. A drive box 42 fitted to the bed-plate 15b of the machine contains three shafts 60, 70 and 74 adapted to be oscillated via a train of gears 36, 40, 41 from the bed shaft 9. An arm 96 rigid with shaft 79 is connected by a double ball-jointed link 95 to an arm 92 rigid with one end of a shaft 89 which is journalled in a bracket 85 fixed to the needle-feed arm 31, and carries at its other end the upper looper 91. An arm 106 rigid with shaft 74 is connected by a link 105 to one arm of a bell-crank lever 101, the other arm of which carries the vertical looper 104. The spreader-carrying shaft 28 is disconnected from its normal drive and is connected by a link to an arm 111 which is rigid with shaft 70 and passes through a slot 44 in the bed-plate. Spreader 25 is re-positioned to compensate for the greater travel of shaft 28. In alternative constructions the original driving connection to shaft 28 is retained, but spreader 26 is removed and is replaced by an independent spreader carried by an arm pivoted either about a horizontal or a vertical axis, said arm being connected by a link to arm 111 which is then arranged to oscillate in a notch 45 formed in the bed-plate. The work is trimmed in advance of the stitching point by a movable blade 134 cooperating with a fixed blade 139. Blade 134 is carried at one end of a resilient arm 132, the other end of which is bent through 90 degrees and is pivoted within a horizontally-forked block 131 rigid with an oscillating shaft 82 also projecting from the drive-box 42. A yoke 138, embracing block 131 and pivoted thereto, carries a screw 136 which bears on the bent end of arm 132 beyond its pivotal axis to bias a finger 135 extending from blade 134 against blade 139. The throat-plate 18 is apertured to expose the feed dog 19, the fixed blade 139 and a chaining- off finger 141 which extends rearwardly from the latter. The work-supporting plate 15a is provided with a slide plate 16 which partly embraces the throat plate and affords access to the under loopers. Specification 802,833 is referred to.