Patent GB-404205-A (GB)
Title: Sewing machine
IPC: D05B73/12
Filed: 1933-06-02
Abstract: 404,205. Sewing-machines. FAIRWEATHER, W. C., 65, Chancery Lane, London.-(Singer Manufacturing Co. ; Elizabeth, New Jersey, U.S.A.) June 2, 1933, No. 15971. [Class 112.] Hem-stitching machines; needles vibrating laterally.-In a machine with a pair of endwise reciprocating needles, the needle actuating mechanism has means for vibrating the needles laterally in directions towards and from each other. A pair of chain stitch loopers co-operate with the needles at the relatively remote sides thereof. In operating the machine, the piercer 43 commences to descend before the needles have quite finished their upstroke, the piercer reaching the end of its downward stroke at about the time the needles 15, 16 are entering the work. The work is advanced by the feed dog 59 and the needles enter the pierced hole close together. While in the work, they are moved slightly sideways away from each other. If the needles lag in the sideways movement, a wedge shaped pin 174 ensures proper movement for seizure of the needle loops N', N<2>, by the loopers 106, 107. These begin their advancing movements in a horizontal plane at about the time the needles are entering the work and reach their loop-seizing position directly after the needles spur 1071 and thus carried forward to a position for entrance by the fang 160. When the fangs 160, 161 are about midway of their advancing movement into the needle are looper loops, the commence their upstrokes. At this time the piercer 43 has emerged from the work another loop-detaining and spreading fangs 160, 161 are pausing in their retracted position with the pin 174 between the needles, so preventing mutual interference of the needle loops. At the extreme forward limit of their movement, the loopers are shifted slightly sidewise to provide clearance for the fangs 160, 161 which at this time begin their advancing movement. The blade of the looper 106 enters the needlethread loop N' and the loop of the looper thread L is opened by the lateral movement of the looper 106 for entrance by the fang 161. The needle-thread loop N<2> is entered by the point of the looper 107, being detained by the loops are held spread. As the fangs 160, 161 reach their extreme advanced position, the loopers 106, 107 are on the point of shedding the needle thread loops N<1>, N<2>, with the needle loops N<1> embracing the looper-thread L, the needle loop N<2> detained by the fang 160 and the looper-loop by the fang 161. The piercer begins its succeeding work-penetrating movement at about the time the loopers begin their retreating movement, and the needles reach the top of their stroke when the fangs 160, 161 have completed their advancing movement, the needles being shifted further apart as they approach the upper end of their stroke. Presser feet ; pressers with periodic control. The presser has a shank 84 secured to the usual spring-depressed bar 85. The shank 84, Fig. 20, has a foot-plate carrying bracket 86 recessed at its under side to provide for vertically yielding movements of three spring tongues 87, 88, 89 formed adjacent to each other in a flat spring plate 90. A foot-plate 94 carrying a spacing block 95 for the attaching screws of the springs is provided. A spacing block 100 is fixed on the upper face of the tongue 89 and carries a foot-plate 101. A chaining off foot-plate 98 is also provided. These plates are resilient by reason of the three springs to accommodate various thicknesses of work. A horizontal compensating plate 102 is provided for properly distributing the presser bar pressure on the spring plates. On the forward end of the rock shaft 35 is an arm 203 with a boss 204 projecting into an aperture in the arm 3. A spring- pressed plunger 205 slides in the boss 204 and is normally urged out of engagement with a cam-nose 206 provided with a spur-gear 40, the usual means being provided for latching the plunger in cam-nose engaging position. On the rear end of the rock shaft 35 is an arm 207 connected by a link 208 to the usual presserfoot lifter-lever, so that the presser is intermittently lifted in the operative position of the plunger 205, to permit turning of the work. Thread - tensioning device. A bracket 240 carries tension discs 242, a thread nipper 243, tension-releasing pins, a nipper releasing pin and a thread guide 250. The looper thread is controlled by tension discs 212, Fig. 13. Upper and lower shafts, connecting. The upper shaft 5 and lower shaft 128 are connected by a vertical shaft 136 and bevel gears Lubricating. A wick in the holder 185 allows lubricant to drip to the lower shaft through holes in a bearing sleeve 184.