GB1384124A - Bobbin thread replenishing mechanism in a sewing machine - Google Patents

Abstract

1384124 Sewing; bobbin winding SINGER CO 18 April 1972 [23 April 1971] 17964/72 Heading D1G In a lock-stitch sewing machine a bobbin 95 is rewound using needle thread N which is guided from the reciprocating needle under the bobbin case 50 and through a thread tension bracket 82 (Fig. 12). A spring arm 62 holds the bobbin in the bobbin case 50 (Fig. 4) which itself is held in a rotary hook 28 but is prevented from rotating by the downturned ends on arms 56 and 64. To rewind, an arm 136 on a shaft 132 is moved clockwise across the bobbin (Fig. 6), and the shaft rotates a cam surface 128 into contact with the nose 128 of a stud 115 and raises it. The stud raises a bracket 112 which supports the rotating shaft 102, the top end of which 101 is thus brought into engagement with the bobbin. This bobbin driving shaft is driven through bevel gears 29, 30 from a bed shaft 22 (Fig. 1). When the machine is started the loop taking beak 42 seizes the needle loop as usual. A projection 143 on the arm 136 is so positioned as to direct the upper part of the thread N (Fig. 6) behind the tension spring 82. As the bobbin rotates this thread passes into a slot 97 in the upper flange of the bobbin and continued rotation of the bobbin winds it on. The thread loop on the beak has been drawn off it meanwhile, and the thread assumes the position shown in Fig. 12 as the bobbin takes up the slack. The top thread (Fig. 12) is severed by being repeatedly rubbed across an edge 160 of the arm 136 as the bobbin rotates. Passing the thread under the bobbin case is said to reduce the possibility of the rotating beak accidently seizing any slack which might form in the thread (Fig. 3, not shown).