Figure 1. Showing blank for paper box, cut to proper size, scored,
but with corner-pieces not yet removed.
The next operation is in removing the corner pieces from the blanks. This work is performed with the aid of a cornering machine. There are single, double and quadruple cornering machines in some of the larger plants, but the single and double cornering machines seem to be the most popular. The single cornering machine removes only one corner from the blank with one operation; the double cornering machine cuts out two corners with a single operation and the quadruple machine removes all four corners with one operation.
Power Double Cornering Machine.
The cornering devices are equipped with cutting knives, arranged so that they may easily be adjusted. The guides may be adjusted so that many different sizes of corners may be cut out of the blank stock. As many as twenty or more blanks may be placed under the knives at one time. The double cornering machine has two sets of knives and guides which are adjustable to provide for the various sizes of blanks. In the same manner the knives and guides of the quadruple machine are adjustable to provide for many different sizes of stock and also various sizes of corners.
When feeding the blanks into the single cornering machine, it is necessary, of course, for the operator to feed the sheet four times before all of the corner pieces have been removed.
When the four corner-pieces have been removed from a sheet of stock, the blank has the following appearance:
Figure 2. Showing blank for paper box, cut to proper size, scored
for folding, and with corner-pieces removed.