How Machines Sew

The first challenge in the development of the practical sewing machine was the design of an apparatus that could make a mechanical stitch. The second was the refinement of that apparatus into a reliable machine able to make stitches by the thousand, continuously and without a hitch.

From the beginning the most common type of work was the lock stitch, using two threads. In both the Hunt and Howe models, a curved needle threaded at the point pierced the cloth and then withdrew, under the control of a hand crank. When the curved needle was at its apex, the thread was stretched out “something in the manner of a bowstring,” as Howe wrote in his patent, “leaving a small open space between the two.” Through this space moved a shuttle shaped like a little rocket ship, carrying the second (bobbin) thread. As the needle receded back through the cloth, the shuttle returned to its original position, having secured both threads in a crisscross.

Elias Howe’s machine stitched, but with the clatter of wasted motion, emanating primarily from the shuttle and the “very bungling device” (in the words of a competitor) that was supposed to help create the loop. Furthermore, the operator had to realign the cloth after every six inches.

Through the uncoordinated efforts of a half-dozen subsequent inventors, the sewing machine emerged on fairly standardized lines by 1856. To allow for uninterrupted sewing, the stationary basting plate, which secured a length of cloth with pins, gave way to a revolving belt, also using pins; this was soon replaced by Allen B. Wilson’s four-motion feeder, a toothed plate facing up against the bottom of the cloth. The teeth pushed the cloth forward the length of one stitch before the whole feeder plate rolled down, back, and then up for another “bite.” Isaac Singer developed the yielding presser foot, to hold the cloth in place against the action of the feeder.

Various shuttle systems remained in use, many of them pointed at both ends to make stitches coming and going. But the smoothest action came from Wilson’s revolving hook, which took hold of the loop at its beginning by the eye of the needle and then, instead of putting the bobbin thread through the loop, pulled the loop around the entire bobbin and thread. The loop was managed through a series of tension regulators leading from the spool to the needles, giving slack when necessary and pulling taut on cue. Precision in the feeding and bobbin systems eventually allowed the sewing machine to outgrow the curved needle.

All these inventions were well covered in patents, but the single most important factor in the sewing machine was synchronization. Without it the thread would snap or the stitches would be loose. With it the two separate systems of the sewing machine—the oscillating needle with its mechanism above and the bobbin with its mechanism below—work together perfectly.