BAND SAws.--While the hand saw was invented about the year 1808, it did not come into use until 1835, since which time there has been a gradual but steady and satisfactory devel opment along, various lines of design and work, Its use takes in practically nearly every kind of wood sawing, both curved and straight lines, from very delicate outside fret-work to the heaviest logs ; the latter having band-wheels as large as 96 in, in diameter, carrying 8-in, saws 50 ft. long, A band resawing machine made by the Egan Co. has the two front feed rolls close to the saw blade, and the tops of the roller brackets are connected, so that the plank may be straight erred while sawed. The wheels are of iron with steel spokes. and their mandrels run in self-oiling boxes. The lower wheel is thicker and more solid in the rim than the upper, giving it more momen tum, although it may be readily stopped by the brake. Each wheel is supported by an outside bearing each side of the column, giving three bearings each to the upper and the lower shaft. The feed consists of six large geared rolls driven by a graduated feed, so that the speed eau be changed at once by turning a hand wheel while the board is being fed through the machine. A ratchet lever connected with the upper permits changing the latter to suit the width of board being cot.
Another band resawing machine, Fig. 10, has vertical feed rolls, the front two of which are close to the saw bed, and the system of employed permits the plank being straightened sawing. The wheels are entirely of iron, and the lower one is thicker and more solid than the upper, giving a certain amcunt of momentum where it is desired to make the sawing steady, at the same time being within the control of the brake. There are six large feed rolls, heavily geared, and driven by a graduated feed, which permits the speed to be changed instantly, by a hand wheel, while the board is being fed through the machine. By a running lever handy to the operator, the upper guide may be changed to snit the width of board. The Egan Co. has made a band resawing machine which will saw a plank into two 1-in. boards at one cut,
thus effecting a considerable in lumber.
The firm of 'Marston & Co. makes a hand and foot-power band saw with both hand crank and treadle, and which for out side work will act faster than a hand jig saw. This machine has a capacity of 6 in. in thick ness under the top guide, and swings 15 in. between the saw and the frame. The table is rounded for -cutting on the bev el. The speed-multiplying rig consists of a large spur wheel on the crank shaft. meshing with a pillion on the lower band wheel ; the shaft bearing the latter having a fly-wheel to steady the motion.
For band resaws a very de sirable attachment or feature is the duplex reversible table and rolling guides, shown in Fig.11, the column being broken away in large part. The table is made in two sections, divided upon a line at right angles to the saw teeth. On the front section of the table are mounted the feed works, consisting of four geared rollers having a gradu ated friction feed, which may be varied at once from slow to fast. These feed rollers hare lateral adjustment to suit the thickness to be cut. By loosen ing a nut in front, upon which the outer section of the table is mounted, it may be turned com pletely over, its lower side when so reversed forming a clear table for plain band-sawing purposes.
A band-saw snide. Fig. 12, made by Goodell & Waters, has two side guides consisting of metal plates, which are adjustable for thickness of the blade, and a wheel with a back guide, the latter having a grooved or concave periphery, and being set on an angle so that the back of the saw passes diagonally across the wheel periphery, and rotates it. Thus the point of bearing of the wheel against the back of the saw blade is constantly changed, and the saw is prevented grooving the surface of the wheel by continued action in any one place. The saw has a bearing of 1* in. at the back, and is not liable to twist or turn, even if the side pieces are removed. The wheel runs on a ball bearing.