Patent GB-765839-A (GB)
Title: Automatic welt turning apparatus
IPC: D04B11/32
Filed: 1952-12-02
Abstract: 765,839. Knitting. COBERT, A. J. Dec. 2, 1952 [June 21, 1952], No. 30514/52. Class 74(2). For topping welt fabric loops on to co-operating needles 101 of a straight bar machine, there are provided a series of vertically disposed, upwardly projecting transfer points 109 supported rearwardly of said needles to co-operate with a transfer hook bar 110 bearing vertically disposed transfer hooks 111, to transfer fabric loops from the hooks to the transfer points, which points are arranged to cover the beards of said needles for transfer of said loops to the needles. If the machine is started up empty, the first few strokes are idle, during which the welt turning mechanism is placed in the starting position. In continuous knitting the welt turning mechanism is started as the toe of the preceding stocking is nearing completion. The welt bar 110 first tilted to bring the hooks 111 from a substantially vertical attitude to a horizontal attitude. At the same time, the welt bar assembly is moved outwardly away from the narrowing frame 112 and descends. The welt bar assembly now moving towards the needles, the welt hooks are positioned between them, receive the first row of loops and are then drawn away from them. After knitting of about a hundred courses, the welt wire assembly is lowered to position the welt wire 285 on the fabric, the welt bar having swung to the limit of its arcuate movement away from the needles, rising slightly in doing so. The welt wire depresses the fabric and moves under the welt bar, pulling the fabric back from the hooks. When the first row of loops has been pulled back to barbs 111<SP>1</SP> on the welt hooks, the welt bars are raised and tilted to position them closer to the needles and to allow free movement of the welt wire. The welt bar and fabric tension rollers 316, 317 are next wound inwardly, the rollers being separated to allow passage of the welt wire between them. After a further fifty or so courses, the welt bar is first moved inwardly (Fig. 32, not shown), to centre the welt on the welt wire, and then retracted, Fig. 33, to provide slack in the fabric. At the same time, the rollers 316, 317 are closed and the welt wire moved towards the needles. The welt wire being smooth and the rollers soft and urged together with little pressure, the wire easily forces its way between the rollers, leaving the fabric behind, and is later withdrawn to inoperative position. The welt bar is now raised to a level at which it can be locked to the narrowing frame and is tilted to bring the hooks substantially vertical and the welt wires are retracted to their inoperative position. The welt bar is then locked to the narrowing frame 112 and the two descend, the welt hooks 111 and transfer points 109 interengaging so that the hook and point embed themselves each in a groove in the other, the loop being above the point of contact between them, but low enough to come below the sinkers 103 which, after being retracted to permit free passage of the fabric, are advanced as the interengaged hooks and points ascend in unison. The advanced sinkers force the loops down on to the transfer points, the freed welt hooks rise clear of the fabric and the transfer bar is moved slightly towards the sinker head 105. The needles 101 now move inwardly, to engage with the transfer point 109, the needle beards becoming embedded in the grooves of the point; and needles and points rise together, so that the needles slide through the loops. The needles continue upwardly to their knitting position in readiness for the next course, the transfer points move downwardly and backwardly to the inoperative position and, as soon as the welt hooks are clear of the loops, the narrowing frame carries the welt bar upwardly to a rest position, after which the welt bar is unlocked and moved to the inoperative position. After the welt has been turned, the rollers 316, 317 are so released that only the fabric prevents their falling outwardly away from the needles; the fabric is thus tensioned, the tension being kept constant by spring means. The lower roller 316 is normally under the action of a pawl, take-off tension being variable by adjustment of a spring. When the roller assembly is moved inwardly to the welt turning position, this pawl itself is not directly operative, but an auxiliary pawl, operated from it through Bowden wire, takes over. Specification 765,841 is referred to.