| 摘要 |
<p>1465806 Sewing machine; zig-zag drive SINGER CO 13 June 1974 [16 July 1973] 26194/74 Heading D1G Changes in position of the needle bar in a swing-needle sewing machine are effected by changing the total axial length of a stack of cam discs using electromagnets. One end disc 70 is made fast to the shaft 25, and the position of the opposite end disc along the shaft is 'monitored by a roller 31 and conveyed to the needle gate by a pivoted lever 29 and the bar 26. Alternate discs 50 in the stack are keyed to the shaft 25, the others 60 are freely rotatable. When elements 80 and 97 on adjacent discs are aligned the discs separation increases by one increment: by aligning the appropriate discs the desired total length of the stock may be achieved: by arranging the elements 80 and 97 of different discs to be different heights a binary sequence of increments may be generated. Due to friction between them all the discs rotate together unless interrupter arm 100 is moved by its electromagnet 104 to intercept a stop member 92 or 95 on one of the freely rotating discs 60. As the adjacent keyed disc continues to rotate the element 97 on the stopped disc rides up or down a ramp 81 to either add one increment to or subtract one increment from the length of the stack. Once the element is in its new position the interrupter arm is moved away from the stop member to allow the disc 60 to rotate again in its new angular position with respect to disc 50. The interrupter arm is kept out of contact with the stop elements by eccentric cam surfaces 75, 76 on disc 50 until the stack length is altered again.</p> |
