| 摘要 |
1484719 Sewing machine; looper adjustment SINGER CO 31 Oct 1974 [15 Nov 1973] 47286/74 Heading DIG [Also in Division F2] In a sewing machine having a rotary drive shaft 20 and an oscillatory stitch forming instrumentality an adjustable throw eccentric is provided on the shaft, a pitman 22 connecting the eccentric to the instrumentality (in this case a looper 15 Figs. 1 and 2 not shown). The eccentric comprises an inner eccentric member 60 having an outer flange 64 and a radial slot 65, and an outer circumscribing eccentric member 61 having a flange 69 provided with holes 70 bearing screws 71 which extend through slot 65 to engage the drive shaft and lock the assembly in a selected relationship with the shaft. To adjust the eccentricity the screws are slackened and member 61 rotated relatively to the rest of the assembly, indicia a-c and x on flange 69 and pitman 22 co-operating to indicate primarily the eccentricity set and being related in this case to the needle size. It is stated that rotation of part 60 on shaft 20 allows alteration primarily of timing, indicia a-c on flange 64 being provided. Looper Drive. The eccentric assembly (21) drives a rock shaft (25) connected to a rock frame (26) bearing spaced arms (30, 31) between which a looper carrier (35) is pivoted on a pin (38). Rocking movements of the frame (26) provides the needle avoiding movement of the looper bill (15), endwise movements being derived from a crank mechanism (43-52). |
