Fig. 40.
Dubied System of Double Locks.
Fig. 40 shows a type of double lock used in a Dubied machine made in Switzerland. The reader will understand from what has gone before that this illustration shows the locks turned upside down, that is, if they were in operation on a machine they would be turned over with the cams close to the needle plates. It will be noted that the fundamentals are the same as in the Lamb system previously described, but the method used to change from the plain rib to the full or half cardigan, or vice versa, is different.
In making a plain rib fabric the needle butts would follow the camway as in the Lamb system, that is, if the carriage were being moved from left to right the needle butts would follow the course up with cams 1a, 1b and 1c below, and 1, 1s, 8s and 8 above. This explanation would of course apply to all four sets of cams. The cams 1b, 2b, 3b and 4b have studs which project through the cam plate and there are means provided to draw any one or all of these cams back through the cam plate by these studs far enough so that the faces of the cams are flush with the cam plate, and entirely out of operation.
The cams 1c, 2c, 3c and 4c are made to swing on the pivots, aa, and are held down on cams, 1a to 4a, in the position shown, by springs. It should be particularly noticed that the cams just mentioned, 1b to 4b, and 1c to 4c, are exactly alike in the four sets of locks, but their positions are reversed in the sets opposite. They are placed in this way in order to facilitate the making of the cardigan stitches.
Making Half Cardigan Stitch
In the study of what follows it should be remembered that the illustration at Fig. 40 shows the locks bottom up, therefore in actual operation the lower set in the illustrations would be the back ones, and the upper set the front ones.
In making the half cardigan stitch it is customary to have the tuck or holdover stitch on the back plate; on the double-lock machine, where we have two feeds, it is on the back feed, and the plain course is on the locks that are leading. Therefore, to make a half cardigan stitch with these locks we would simply raise cams 2b and 3b up through the cam plate out of working position.
Now remembering that the cams 2c and 3c are free to swing up and down on the pivots, aa, and are held down in their present position by a small spring, it should be readily understood that in moving the carriage from, let us say, left to right, the butts of the needles would follow up the right side of cam 2a, and on up over 2c, therefore would knit out on this course. But when these butts came to the second set of locks they would move up the right side of cam 3a until they came to the upper right hand corner of this cam, and at this point, on account of cam 3b being up out of operation, they would move across and raise up cam 3c and pass under it. Cam 3a not being high enough to raise the needles to the point where the stitch would drop off the latches, obviously the needles must hold the two stitches on this side of these locks.
On the return of the carriage from right to left the operation of the needles would be reversed, that is, they would pass up over cam 3c and knit out on the locks in the lead and pass under cam 2c.
To sum up the whole operation in a few words, to make a half cardigan stitch we must alternate with the plain rib course and a course that tucks or holds the previous stitch, as well as the new one on one side. This half cardigan is the stitch used in making what is known as the “cotton back” sweater and other such fabrics.