A Manual of Shoemaking and Leather and Rubber Products

by William H. Dooley

Notice should be taken of the difference between the way the outsole is stitched and the inner sole is stitched to the upper. In place of three threads in the chain stitch “that holds the welt to the upper and insole” there are but two here—an upper and a lower one. The upper thread extends only part way down, where it loops, twists, and locks into the lower thread. This is the reason why you can wear a welt sole clear through without its pulling loose.

Shoes that are stitched aloft go through the same operations as the channel-stitched shoes, with the exception that the rounding machine contrivance of cutting is eliminated.

Shoes that are to be fudge stitched are sent through the same machine as the regular stitched aloft, but an additional little knife point on the arm of the Goodyear stitcher digs a channel in the welt so that the stitches on that side are sunk into the leather.

The outsole is nailed at the heel after the stitching on the “loose nailing machine,” which drives the nails through the outsole and insole and clinches against the steel plate of the last. The machine drives separate nails fed from the hopper of any desired size or length, at the rate of three hundred and fifty per minute.

The edge of the outsole around the heel is now trimmed to conform exactly to the shape of the heel on the “heel seat pounding machine.”

The stitches of the regular stitched shoes are separated by a series of indentations, giving the shoe that corrugated effect which adds so much to the appearance of the shoe. In the fudge-stitched work the stitches are entirely covered up by the indentations.

Then a leveling machine, called the “automatic sole leveling machine,” with a pressure of about two and a half tons to each of the concave rollers, comes into play. The rolls move automatically back and forth and from side to side, doing the work that the shoemaker used to do on his lap with a hammer and stone, but doing it better and more quickly. It practically levels off the bottom of the soles.

An automatic guage regulates exactly the distance from the edge of the last, and by the use of this machine the operator is enabled to make a sole conform to that of all others of a similar design and size.

Heels are formed by cementing different lifts of leather. A machine called a “heel cutter” shapes out the lifts. The heel is then placed under pressure, giving it exact form and greatly increasing its wear.