Patent GB-885779-A (GB)
Title: Improvements relating to sewing machines
IPC: D05B73/00
Filed: 1958-03-19
Abstract: 885,779. Sewing-machines. ANKERPHOENIX NAHMASCHINEN A.G. March 19, 1958 [March 20, 1957], No. 8828/58. Class 112 Frames. The base of a sewing machine is provided with one bore disposed transversely to its longitudinal axis and at least two bores, disposed parallel to that axis, the bores being available to accommodate alternative loop taker driving gear according to the type of loop taker drive to be installed. The base is open at the top and bottom and is provided with a snap-on cover. Driving by motor. A motor in the base (see Fig. 9) drives an arm shaft 3 by means of a belt which engages the handwheel 4. A pulley 20 mounted on the arm shaft engages a belt 21 which drives the lower shaft 22 (see Figs. 11 and 17) or 62 (see Fig. 14). Feed by dogs, reversing and regulating. A feed bar 43, which carries at its free end a feed dog, has its other end engaged by levers 47 on a feed advance shaft 35. A feed member 33 encircling an eccentric 31 mounted in the shaft 22 has one end pivotally connected to the end of a crank 34 mounted on the feed advance shaft 35. The other end of the member 33 carries a pin 46 on which is carried a sliding block 36 engaged with the groove in a slotted guide member 37. This guide member is angularly adjustable (see Fig. 13) by a stitch setting handle 40 to vary or reverse the feed advance motion. The feed lift motion is imparted directly to the feed bar 43 either by a cam 32 on the shaft 22 (see Figs. 11 and 17) or by a cam 71 on the loop taker shaft 66 (see Fig. 14). Actuating needles, needles shifting laterally, needle thread take-ups. The lower eye of a thread take-up lever 7 (see Fig. 8) is journalled on a stud 6 secured to a crank 5 mounted on the arm shaft 3. The upper eye of the lever is pivotally connected to a take-up link 8 pivoted to the arm of the machine. A needle bar link 11 is pivoted at its upper end to an eccentric boss 10 mounted on the stud 6, the lower end of the link being pivoted at 12 to a needle bar block fastened to the needle bar 13, to reciprocate the latter in the needle bar support 14. This support 14 is secured to the arm of the sewing machine when the latter is to be used as a straight stitch machine, but is pivotable about pintles 15, 16 when zig-zag stitching is required. The swinging motion of the support 14 is then derived from a cam 114 (see Fig. 9) driven by 2:1 ratio spiral gears 112, 113 from the arm shaft 3. A spring-urged connecting lever 116, pivoted at 120 to the top of the needle bar support driving lever 121, engages a side face of a cam follower 115. A slot 117 in the end of the lever 116 is engaged by a pin 118 secured to a manual lever 119 by means of which the magnitude of the zig-zag stitches may be controlled. To provide decorative stitching the spiral gear 113 may be replaced by a gear (Fig. 10, not shown) which has a cylindrical extension on which may be placed a cam disc of selected shape to obtain a particular stitch formation. Actuating rotary hooks. Figs. 11 and 17 show respectively arrangements for driving a hook rotating in a plane transverse to the line of feed and a hook rotating in a plane parallel to the line of feed. In the first case the shaft 22 drives, by means of spiral gears 79, 78, a shaft 76 carrying at its end a rotary hook, the bores 157 and 81 in the base 2 being utilized for this purpose. In the second case the shaft 22 drives, by means of gears 24, 25, a looper shaft 26 running in an eccentric sleeve 27 carried in a bore 127. The provision of the eccentric sleeve allows the upper position of the point of the hook to be adjusted. Actuating shuttles (see Fig. 14). In this arrangement, in which the bores 128 and 127 are utilized the shaft 22 is replaced by a shorter shaft 62 having at one end a crank 63 connected by a link 64 to a gear wheel 24 so as to oscillate the latter, about a shaft 65 carried in the bore 128, as the shaft 62 revolves. A gear 25 is secured to a shaft 66 and meshed with the gear 24 to oscillate the shaft and hence the oscillating shuttle 70. Work supports. To permit access to the hook or shuttle irrespective of whether these move in planes parallel or transverse to the lines of feed an access plate (see Fig. 4a, not shown) which surrounds three fourths of a circular stitch plate is provided. The plate is retained in position by leaf springs. In a modification (Fig. 4, not shown) the stitch plate is of triangular form with an access plate hinged along one side of it. Specification 885,780 is referred to.