Flat Machine Knitting and Fabrics

by H. D. Buck

Fig. 56.
Needles and Needle Springs Used in Automatic Widening Machine.

These cams are arranged so that normally they are raised up in the cam plate and pass over the lower butts of the needles, but they may be lowered to operate the needles and raised again, all automatically, at the proper time and place by slides and levers similar to those described in a previous article on the automatic machine. The manner of returning the widening needles to their lowest position so they will be out of operation should be obvious to the reader after the foregoing explanations and a study of the illustrations.

When the time comes to cast off these added stitches in order to start a new sleeve or fabric, the plate on which cams c1 and d1 are attached is automatically lowered when the carriage is over to the extreme right. Then upon its return the lower needle butts of the widening needles will come in contact with the left side of cam d1, and moving up over the top of this will, of course, raise the needles to a point where the latches are above the stitches. As the carriage moves farther along, and the butts come in contact with the left side of cam c1, they will slide down and cast the stitches off over the latch and hook, and at the same time be drawn down to a point so low that the knitting or upper cams cannot operate on the upper butts.

At the same time that the cams c1 and d1 are lowered to cast off and draw out of operation the widening needles, a plunger, which is attached to the carriage, drops down and engages a recess on the under side of the yarn carrier stop i, Fig. 54, and through the lug j moves the lever f, together with the slide g and stop h, back to its first position where the plunger is disengaged by an inclined stop. The stop h will hold this part of the mechanism in this place by contact with the first needle spring as explained before.

It should be understood that while this explanation covers only one of the four corners that must have the needles pushed up to widen the fabric, the method applies to all of them. Also in the manner of casting off the widening needles and returning them to their lowest positions preparatory to starting a new fabric, we have confined ourselves to the right end of the front plate only in order to present the matter in the simplest possible manner. In actual practice the pair of cams on the left, indicated by c3 and d3, together with c4 and d4, are put into operation first by a medium stud on the widening chain while the carriage is at the extreme left end. Upon the return movement of the carriage these cams would cast off and return the widening needles to their lowest point on the left end of both front and back plates. Immediately this is done the cams are released by means provided, and they again rise up into the plate out of the working position, thus passing over the right side widening needles without effect.

After putting on one full round the cams d1 and c1, together with cams d2 and c2, are put into operation at the extreme right end of the machine by a high stud on the widening chain, and these cast off and draw down out of operation the front and back widening needles on the right in the same manner as heretofore explained.

Yarn Carrier Stop

The reader will realize from what has gone before that when there are needles added to or taken from the edge of a fabric, while in the process of knitting on a machine, it would be necessary to arrange to change the stopping position of the yarn carrier in order to prevent it from stopping too far away from or too close in to the fabric as the widening operation progresses. This is done by the simple expedient of having the yarn carrier stop mounted on its bar or way so it will slide freely, and providing the lugs j and k, Fig. 54, on both sides of the lever f, so that it, with the lever f, and slide g, with stop h, will at all times move together. Therefore the needle on the edge of the fabric and the yarn carrier stops are always in the same relative position.

If the reader has stopped to ponder on the working of this machine, with the resultant fabric, he may realize that there should be more pull or tension on the fabric during the last part of it than when it is started. As there have been needles added it is wider. This has been provided for so that by placing high studs on the main chain at the proper point they will increase the tension on the take-up rollers where and as much as needed. When the widening needles are cast off, and the width of the fabric is reduced to its narrowest portion, this extra tension may be automatically released and the pull reduced to the proper strain for the narrower fabric.

These machines are made only in the double lock type, but there are means provided through the before described levers and slides to change automatically to single lock by raising one pair of the locks up out of operation. This is quite an advantage where one wishes to make some style of garment with a rack showing on both sides of the fabric such as the turned-up cuff on ladies’ sweaters, etc.