| 摘要 |
564,042. Sewing - machines. UNION SPECIAL MACHINE CO. May 27, 1943, No. 8494. Convention date, June 23,1942. [Class 112] In a lockstitch sewing - machine thread take - up means comprises pegs 60 on a disc 58 and a cam 54, both disc and cam being mounted on a' shaft 47, the two take-ups being additive over parts of the cycle, and subtractive over the other parts. A gear 46, on the shaft 47, is driven by a gear on the main machine shaft, and is supported on bearings in the machine head 13; lubricating holes are provided. The cam 54 is screwed to a flange 53, and the pegs 60 which may have rollers are screwed between discs 58 and 59. The relative positions of the cam and discs may be varied. A plate 62, secured to the head, has a slot 63 through which the cam 54 passes. Thread passes through a guide 75, around a tensioning device 44 which includes a check wire 76, under a pull-off arm 77 carried by a block secured to the presser-bar, through an eyelet 68, over the edge of cam 54, via an opening 69 in the plate 62 and around the forward stud 60. At times the thread passes across a groove 70a in a pin 70. The thread then drops clown to a fixed guide 78 to the needle 15. Fig. 2 shows a minimum length of thread from the pull-off arm 77 and the guide 78, the thread between the eyelet 68 and the opening 69 being deflected only slightly by the cam 54 and passing over the fixed guide pin 70. Fig. 8 shows the thread drawn from the eyelet 68 across the larger diameter of the cam and passing over the pegs 60. In this position the needle thread will have been drawn up tightly against the underside of the work and the check wire 76 depressed. |
