Fig. 32.
The Racking Cam, Ratchet and Studs.
There is a large flat bottom hole, c, bored about half way through the plate; through the bottom of this hole there is made an elongated hole, b, through which the plate is attached to the frame by the shouldered screw, a, the head of which is flush with the top of the plate. It will readily be seen that with this method the plate cannot be moved in any direction except lengthwise of the plate, or crosswise of the needles. To secure this movement at will there is a steel strap, d, attached to the under side of the plate by the screws j and k, and through the outside end of this strap there are two elongated holes through which are attached two shouldered studs with nuts e and f. These studs extend down on both sides of the steps of the racking cam, g, and together with the plate are moved back and forth by the steps on the racking cam. The cam is moved by the handle, i, in the hand machines, or by the ratchet, h, being operated by pawls or dogs in power machines.
The letter h shows a front elevation of the ratchet, while i is a side view. It will be noted that there are only three teeth on each side, and these two groups are opposed one to the other. If the reader will examine the racking cam, g, with due thought the reason for this will be obvious. There are three steps on the cam and the cam must have an oscillating movement and not a rotary one. The ratchet, h, and the racking cam, g, are both attached securely to one hub, therefore must move together on a stud which projects from the end of the frame.
The plate as illustrated in Fig. 32, sets at the limit of its movement to the left, consequently any racking that is to be done must move the plate to the right, therefore the pawl at the top of the ratchet would engage the uppermost tooth, q, and turning the ratchet one tooth would move the racking cam one step, thus moving the plate over one needle through its contact with the studs, e and f. There are two pawls, upper and lower, arranged to engage the teeth on the ratchet either at the top or the bottom as required. If we wanted a one-needle rack only, after putting on one round of stitches we would have the lower pawl engage the tooth, n, of the ratchet and move the racking cam back to its first position. If, however, we wanted a two-needle rack, the upper pawl would engage the second tooth, o, of the ratchet. For three racks it would then engage the next tooth, m, after which it would be necessary to start on the return to the first position, remembering to put on one course or one round, as the case may be, of stitches between each rack. If racking on the half cardigan stitch there should be one full round between the racks, but if on the full cardigan the racking may be done every half round or every course, as will be explained hereafter.
Fig. 33 is a photographic reproduction of a piece of fabric, face and back, of a one-needle rack which shows on one side of the fabric only. A fabric with the two-needle rack which would show on both sides of the fabric is not illustrated, for it would be the same on both sides as the face side of Fig. 33. A line drawing of the rack stitch is shown at Fig. 34. This is drawn out of proportion and is very loose and not like the fabric, but by making it this way the direction the yarn takes may be easily located.
Fig. 33.
Face and Back of One-Needle Rack.
The Zig-Zag Stitch
