II. MACHINES FOR MANUFACTURING PURPOSES AND HEAVY WORK.—The Wheeler & No. 12 Machine, Fig. 10.—In this machine the moving power is applied to the upper revolv ing shaft. which communicates a uniform rotary motion to the lower main shaft by means of two connections and double quartering cranks. The loop-taker (which takes the place of the ordinary rotating hook, such as is used in the No. 9 machine) passes through the loop of upper thread. It moves in a circular guide with a motion alternately accelerated and retarded. It is rotated by means of a driver attached to a short shaft, the axis of which is eccentric to that of the main lower shaft, and which in consequence of the eccentricity receives a variable motion from the motive lower shaft by a link connection, as shown in the figure. The axis of the driver is also eccentric to that of the loop-taker, so that, by reason of this eccentricity, the necessary openings for the free passage of thread between the driver and the loop-taker are alternately formed at either end of the driver. By this arrange ment the loop of upper thread is carried around the bobbin of lower thread without meeting with any resistance. Fig. 11 shows the large bobbin -of this machine, and its case, with adjustable tension spring. Fig. 1'2 shows the bobbin ease in t he loop-taker, with the bobbin-holder thrown open. The automatic thread controller is actuated by the presser-foot through the medium of the presser bar, so that the controller gives automatically in ore or less spread• according to the varying thickness of the goods. This machine is pro vided with a knee presser lifter, by means of which the operator can at any time raise and lower the presser-foot by a movement of the knee, leav ing both hands free for ma nipulating the work.
St ra w hat Machine makes prac tically a concealed stitch. It has a claimed capacity of 1,000 hand stitches per ndn ute. It produces all sorts of plaits, from the coarsest " rough-and-ready " to the finest " Florence Milans."
This is secured by compen sating action between the threader, Ipoper, and presser-foot, whereby the needle automatically adapts itself to the thick • ness of the plait operated upon. The double needles operate from below, and carrying the thread upward through the straw, a looper takes the thread from the threader, and passing over, a small double stitch is made on the upper side, almost invisible, and a long triple stitch on the under side. The hat can be shaped while being stitched.
Two-needle Maehines.—A machine of this class, Fig. 18, made by the Singer Manufac turing Co., is a development of the regular automatic chain-stitch machine. It has two needles, and their stitch-forming mechanism. the hook being underneath, is so arranged as to pick up both threads. The gauge, or distance, from one needle to the other can be varied by intervals of in. from & in. ton in., by substituting feeds, throats, and needle clamps suitable for the required width between seams. These machines are used in corset work, for staying shoes, and for all manner of double seams. A reel is provided for carry ing tape or staying material. The same result is obtained by having two chain-stitch machines attached to a base, one being adjustable in relation to the other, so that the width between seams can be varied from 21, to 16 in., and the length of stitch from 8 to 30 to the inch. An other form of two-needle machine, made by the Singer Co., called the "three-stitch zig-zag machine," makes two rows of stitching, and three lateral stitches in each direction before reversing, and can be fitted to make less or more stitches.
The Singer Two-needle, Two-shuttle Sewing Machine.
—This is a lock-stitch machine, having oscillating shuttle mechanism, and is fitted with two needles set to any desired gauge, with two shuttles (right and left) to correspond, and both actuated by the same shaft. It makes two complete and uniform rows of stitching, and is used in making shirts and corsets, India-rubber clothing, etc.