. _ Bracket stationary cut-off saws appear in two principal varieties, one in which the bracket is fastened to a post or wall, and another in which it is borne by a special cast-iron column. The bracket has a vertical adjustment upon the column, where there is one, and upon the wall plate where there is no column, The arbor runs horizontally in a sliding gate-way gibbed to the face of the bracket. The table bearing the work is at right angles to the bracket and has rollers to facili tate feeding along the stuff. The table has vertical adjustment by hand wheel, to suit the thickness of the material being cut or the wear of the saw to smaller diameter.
A vertical cut-off saw made by the Berry & Orton Co. has a vertical column, tip and down one face of which there slides a counterbalanced saddle bearing a saw mandrel and its movement up and down, which is by a rack and pinion, is controlled by a treadle. The table which bears the work has adjustment to and from the column to suit different diameters of saws, and also radial adjustment for angle sawing. The same machine may be used for gaining if desired.
In a direct-acting steam cut-off saw by William E.
Hill & Co., the circular saw and its mandrel are on the top of a solid iron frame, planed on its side and edges, and working in adjustable vertical guides. This iron frame is worked up and down by an upright steam cylinder with 28in. stroke, and having steam cushion at each end to permit of high speed of working.
A powerful machine for cutting off and gaining, as in railway, car, bridge, and other heavy work, has a vertical column from which there projects a strong horizontal bracket, on the under surface of which there slides a carriage bearing a saw with horizontal mandrel. Under, and at right angles to this bracket, there is a horizontal table at which is placed the material to be cut off or gained ; this table having, rollers to permit the material to be moved lengthwise to bring the proper mark under the saw. To provide for the use of circular saws of various sizes, and to allow for the cutting of gains of different depths, the arm or bracket is adjustable vertically by screws operated by hand or power. The saw carriage, which traverses the entire length of the arm, is moved by a screw actuated by a friction clutch, the feed being started and stopped by either one of two one at the front of the table and the other at the side of the column, thus placing the machine well under the operator's control. The
saw is driven by au endless belt wrapping around idlers in such a way that it preserves its tightness, no matter how fa-r out upon the bracket the saw mandrel may be.
In the railway cut-off saw of the H. B. Smith Machine Co. there is a horizontal table bearing a horizontal cross-head or saddle, which supports in proper bearings the horizontal mandrel of the saw. This cross-head or saddle is attached to a connecting-rod pivoted at its other end to a frame which vibrates about a center at its lower end, this being the center about which a large pulley rotates. From this large pulley a belt rises and passes over a small pulley near the top of the vibrating frame, then horizontally to the saw pulley, back horizontally to a second or upper small pulley on the v ib rat i ng frame, and down to the lower or large pulley. A long hand lever enables this vibrating frame to be drawn forward, and with - it the saw, giving traverse in the machine. Above the saw bearings are two horizontal guide bars which serve as rests for the stock.
In the swing cut-off saw shown in Fig. 4, and made by Rowley & Hermance, the frame swings upon the hang ers instead of upon the countershaft, as in most other machines ; it is adjustable for different heights of ceiling, the saddle holding the arbor having a sliding adjustment of 5 in. ; thus incidentally permitting the saw being entirely used up. The saw is protected by a shield.
In a parallel swing saw machine made by P. Pryibil, Fig. 5, the saw arbor travels in a horizontal straight line. instead of rising and falling in an arc, as in all swing saws, thus enabling a comparatively small saw to be used for wide and thick timber, and permitting the use of a dado-head for grooving, gaining, rebating, tenoning, molding, etc. The moving parts are balanced so that they will stay in any position in which they may be left. The parallelism is given by the main bearings sliding in vertical grooves, and the pendulum being connected at about the center of its length with a link-piece pivoted at about the height of the saw arbor, as shown in the illustration.
The combination slitting and cut-off saw table made by Beach, Brown & Co., and shown in Fig. 6, has a bed mounted upon roller bearings, so as to make it run easily and square with the saw, For clack cutting, grooving, etc., the saw is raised and lowered by a hand wheel and screw, or for ordinary work by a hand lever.