This section is from the book "The Manufacture Of Boots And Shoes: Being A Modern Treatise Of All The Processes Of Making And Manufacturing Footgear", by F. Y. Golding. Also available from Amazon: The Manufacture Of Boots And Shoes.
For certain portions of the work, dies or knives may be used to advantage. Topbands, facings, inside and outside straps, tongues, etc., may be thus cut under a press. By giving a little consideration in designing the patterns, many of these named parts may be made to serve for several sets of patterns. Offal may be cut by handled dies and mallet even in smaller factories that would not have suitable work for a press.
A clicking press of the Revolution type is illustrated in Fig. 181. The beam, or head, rises at the completion of each revolution, and, when the operator presses his foot on the treadle, it descends and dies out, returning and stopping at the highest point, until released by a second step on the treadle.
Machines for measuring the surface-area of the skins are also used with advantage. There are two kinds usually found in use, the "Sawyer," and the "Justice." The former machine has mechanical means provided for collecting the various measurements observed, when the skin to be measured is placed between the roller or feed and the upper wheel. The "Justice" machine consists of a roller or shaft, so arranged that the leather put on the front board feeds on its highest point. Separated by a slight distance above this shaft, is arranged, some two inches from each other, a number of wheels mounted on levers, pivoted at the back, so that when anything is placed between the roller and upper wheel, this pivoted lever allows the wheel to rise, and automatically adjust itself to the substance of the material used. On the face of each of the wheels an involuted slot is made, into which works a finger, preventing the wheel from slipping without registering.
Attached to the spindle of each wheel is a cord, which is coiled round the drum as the rim of the wheel passes over the material. The cord passes over a pulley at the back of the machine, and is fastened at the other end to a hollow metal cylinder, which works in a tube. Each of the tubes is connected at the bottom with a main vertical tube, in which is placed a float. The float carries a lath, marked in equal units to represent square feet. Before using, the main tube and its tributaries are filled with water. When the cord is coiled round the spindle of the wheel, the tube attached rises, and the water in proportion lowering on the main tube, and, according to the amount lowered, so the scale is effected.
The accuracy of the machine is proved by using pieces of cardboard (cut to a square foot, half square foot, etc.), to mark up a skin, totalling the sections, and thus obtaining the number of feet portioned off. This skin placed through the machine, and the area indicated, coincides with that obtained when using the cardboard patterns.
The skiving, scarfing, or bevelling of the various parts by machine, is often done in this department, so that any damage may be easily replaced, etc. The Douglas skiver (a fixed knife machine) is used for the heavy leathers, and the Amazeen (a revolving knife - see Fig. 187, and p. 247) for the lighter leathers.
Machines for scolloping the edges of vamps, caps, top-linings, etc., are also used, and an illustration of Squire's machine is given in Fig. 182, which is one of the best for this purpose. Toe-cap perforating machines are also used in this department.