Resateing machinery has taken a very important place in the economy of sawing. It has now become the custom almost all over our country to saw the logs at the mill only into stand ard dimensions of considerable size, and to ship these to near the place of distribution and consumption, where they are then sawed thinner, to such dimensions as may be considered most desirable for the local market or special demand. This policy greatly lessens the waste of lumber, in that the kerf taken by the resawing machine in slitting a plank into two boards is less than that made by a heavy log-saw, and also there is less material spoiled by the grit, dirt, and defacing marks which are inseparable from shipment by rail, canal, or raft. The light and rapid resaw also enables a dealer to fill his orders for irregular thicknesses, or for any great quantity of any regular size with reasonable promptness. and without having to keep on hand, drawing interest, and subject to fire risks, an unreasonable stock of lumber.
The resawing machine shown in Fig. 2, and made by Rowley, Hermance & Co., of \I'll liamsport, Pa., has a heavy frame east in one piece. The arbor overhangs the box next the saw, admitting of the latter being easily removed. The saw arbor boxes are connected by a heavy yoke and keyed to the frame, and are moved to and from the rolls by a screw, keeping the saw in line with them. The rolls move upon the platen in pairs and adjust themselves to various thicknesses of lumber, opening 0 in. and permitting a 1-in. board to be cut from a 6-in. plank. One pair of rolls may be made stationary, and lumber of even thickness cut upon that side, and inequalities of thickness confined to the other side. The table upon which the lumber rests being very close to the rolls, permits of sawing very narrow boards. The feed works are reversible, and lumber may be run from the saw more rapidly than to it. The ,platen that supports the rolls turns upon a center for sawing beveled siding, and is regu lated by a graduated index plate. The saw may be lifted out of the frame and kept sus pended on a pin in the center, thus protecting the teeth from bending and twisting.
'The 24-in. circular resawing machine shown in Fig. :3, and made by the Egan Co., is for beveled siding and general planing and furniture work. The frame is one piece, cored out. There are four vertical feed rolls, which work so close to the board rest that a 4-in. strip may be cut if necessary. The feed rolls arc on a swing ing frame, and by the adjustment of a hand nut any angle of cut may be obtained. The feed
rolls are carried together, and the belt which drives them runs from the middle to the counter shaft, and from that to the cone pulley on the feed shaft, so that when the feed mils are thrown on a bevel the feed belt keeps its tension. The feed rolls may be moved all four at once, or only two at a time. There is lateral adjustment by a crank at the end. They are self-centering, and will take any lumber from f, in. to 8 in thick. Those on one side may be made rigid by a crank handle at the side of the swinging frame, to per mit of taking a piece lin. thick from the side of a thick plank, In a resawing machine made by Hoyt & Bro. there is an iron trough which nearly follows the lower periphery of the saw, and merges into is spout which conducts the sawdust clear of the machine, or to a chute or exhaust pipe, thus materially adding to the convenience of the machine.
For the larger grade of resaws, the saws are sectional, having thin sectors fastened by flush screws to a tapering central disk ; the adja cent radial edges of the sectors being joined by dovetail pieces flush with the edges of the plate. and close to the tooth line. Of course, this permits the use of thinner saws than would be possible where a single disk was used.
Various Forms of Circular Sawing _Mark ines.— Of circular sawing machines other than those for log-cutting and board resawing, there many varieties, distinguished or classifiable according as there is one or more than one upon the table, and whether, where there are two, these are parallel and upon the same axis, so that both may be used at once, or are on separate arbors, so that only one may be swung into use at once. In some machines, too, the work is fed to the saw ; in others the saw is fed to the work ; and in those in which the saw is stationary, Lhe work may be fell by hand, or drawn along by a chain upon rollers, or fastened to the carriage and moved with it. In those machines in which the saw is moved to the work, it may be on a carriage or saddle, or swinging at the end of a pendulum. Where it is on a carriage or saddle, its motion maybe either horizontal or vertical, and if at the end of the pendulum it may be pivoted either below or above the work. All these varieties exist ; each of them having some special purpose, and being best adapted for that purpose. Some sawing machines are for ripping, others for cross cutting ; sonic for gaining or grooving as well as for separating.