a new form of power stabbing-machine the main feature is that the awls revolve. While going into and coming out of the work, they turn, thus operating much easier, especially in thick books and a smoother and smaller hole than when the stabbing is done in the usual way. A pinion on the driving-shaft meshes with a gear upon the eccentric shaft. and the eccentric, through a vertical yoke and cross-bar connected to vertical slide rods passing through the table, and terminating in the awl causes the latter to move up and down at proper intervals for piercing the work. The travels upon stationary guide-burs which have their own fixed head. containing threaded boxes which receive the correspondingly threaded upper ends of the awls, in this way impart ing rotary motion in reversed directions to the awls as their c•ross-head is moved up and down by the eccentric. In forming backs for blank-books, and for small job-work, a simple ma chine is employed which has two pairs of rolls, of different sizes, journaled in a plain upright frame which is fixed to a table. One of each pair of rolls has self-adjusting spring bearings, and each pair is geared together. A key-crank turns either pair of rolls at the will of the
operator, according to the size of back he is making. The rolls are heated by gas. by gas pipes placed back of the rolls, and both pairs can be heated at once or separately. Each roll has an apron attached to it. The book back is formed by wetting it on one side with a sponge, and feeding it in dry side next to the roll. The roll is stopped for a moment just before the back passes out, so as to give it a chance to take shape and harden ; then it is released. Bands are formed in the same way by setting them in a band board and feeding them to the roll. Among the advantages are the facilities for forming different sizes and thicknesses of backs in the same machine—and a dozen or more bands at the same time as one—while producing harder and better work than can be done by hand, and saving time and labor.
see Tioring Machines. Metal: Boring Machines, Wood ; Lathe Tools, Milling Machines, Mortising Machines, and Wheel-Making Machines.