Patent GB-525976-A (GB)
Title: Improvements in the welt turning mechanism of straight-bar knitting machines
IPC: D04B11/32
Filed: 1939-03-04
Abstract: 525,976. Knitting. BLACKBURN & SONS, Ltd., G., START, H. W., and START, E. March 4, 1939, Nos. 7124 and 19770. [Class 74 (ii)] Welt turning mechanism for a straight-bar knitting-machine comprises a set of points 1 for removing the loops of the first course of loops and a set of welt hooks 6 for receiving and retaining them unti a sufficient number of courses have been knitted. The points 1 are similar to ordinary coverer points but with longer flutes and may replace the picot points Alternate loops of the first course are sunk on alternate needle 4 and the remaining loops on the lower ends of the points. When the needle bar descends, the loops on the needles are drawn into the beards while those on the points are eventually delivered on to the sinker noses. Subsequent movement of needles and sinkers delivers the loops released by the points 1 on to welt hooks 6. Knitting is continued on all needles until a sufficient number of courses to form the welt have been knitted, after which the loops on the welt hooks are replaced on the needles. The first course may, however, be drawn on all needles and alternate loops may be taken from the needles by the points, which may be the picot points, and delivered to the sinkers. To prevent loops from sliding along the stems of the welt hooks 6, stops 6b are provided. The welt hook bar 7 is drawn horizontally away from the needles on brackets 8 by straps attached to take-up rollers 18 and can be moved towards the needles by means of sliding racks 9 with abutments 16 when the welt hook bar has retired to the full extent of its movement, during the knitting of the first portion of the welt, i.e., has moved back into engagement with the abutments 16, the work is further taken up by welt wires 20. These are inserted before the bar 7 has completed its full movement and are operated by straps 21 connected to a take-up roller 22. When the bar 7 has been withdrawn to the position shown in Fig. 17 the welt wires 20 are pressed down on the work 24 and engaged under catches 25 fixed to the brackets 8. The take-up straps 21 are placed in channel shaped guides 26, carried by arms 27, pivoted at 28 and provided with notches 29 which are engaged with the welt wires 20. The straps 21 are then withdrawn under the action of the take-up until hooks 30 engage the wires 20. The guides 26 are then returned to normal position and further movement of the take-up roller 22 draws the work 24 into a loop beneath the welt hook bar 7. The welt wires then continue to take up the work. The operation of returning the loops on the welt hooks to the needles is aided by the use of a bar, instruments on which displace alternate needle stems. The loops are replaced by the points. If the points used for the welt turning operation are the picot points ordinarily in use in the machine, mechanism for adjusting their positon when carrying out their normal function is provided. In the preferred method of replacing the loops, the points 1 may be shogged one needlespace and moved down to shield needles which are not to receive loops, and then moved up after :he loops have been placed in the remaining needles, so that the needles which are not to receive loops pass up through the work.