see Lathes, Saw : see Saws, Metal-Working. Grinding. Machinery, Ore: see Ore-Crushing Machines.
The Sellers Drill-Grinding Machine is represented in Fig. 1, with a drill in place ready to be ground. The drill is carried in a holder which is pivoted to the top of the main upright. The adjustment of the drill to any required angle of point be tween 90° and 130° of included angle is effected by swinging this holder about its center. The lips of the drill are chucked by two jaws, which are opened and closed by the hand-wheel A. The back end of the drill is steadied by an adjustable center-stop B. This stop is made reversible. being provided with a male center at one end and a female center at the other, the latter to be used with the small drills having no center-holes in their ends. The grinding wheel is carried on a shaft at the top of the water-box C. The lever 1), raised and lowered by the right hand of the workman, passes the face of the grinding-wheel hack and forth over the lip of the drill. The hand-wheel E adjusts the face of the stone to the lip of the drill ; that is, it regulates the cut by up the stone closer to or farther from the part to be ground. To this hand-wheel is adapted an adjustable stop, which enables an adjustment to be made separately when grinding each lip, and yet permits them both to be gauged to the same length by means of this final stop. If the final grinding of both lips is made without anv adjustment of the stone, the same result is obtained without the use of this stop. The grinding-wheel iR protected by a cover, except where the drill comes in contact with it. In this cover is a curved water-way, through which water is delivered by an endless-belt pump, and from which it is thrown on the face of the stone and on the end of the drill in a continuous stream. The ball-handle 1', operated by the left hand of the workman, rotates the drill back and forth in front of the grinding-wheel in a way to insure the proper clearance.
The Sellers Tool Grin-ding and Shaping -11achilz-e, represented in Fig. 2, is intended for grinding and shaping all the fares of almost any kind of lathe, planer, slotter, and shaper tools. The main features of the machine are as follows: A grinding-wheel is mounted in it cast-iron frame forming a large tank, which receives the water used for flooding the tool in grinding.
Slide-rests are provided, by which a vertical and two horizontal motions at right angles to each other can be imparted to the tool-holding chuck. The slide-rests and chuck are carried upon a vertical slide, which may be moved up and down by the long lever which is operated by the left hand of the attendant, the object of this movement being to move the tool in a vertical plane up and down past the grinding-surface of the stone, and thus produce a plane surface on the tool. In grinding curved surfaces no vertical movement is given to the chuck holding the tool, but it is made to rotate, to produce the curve desired. If the curve of the tool is not IL eirenIar one, then former" plate is required. Nenns are provided hy which any sample tool, whether ground by hand or otherwise. can he used as a templet for grinding the " former plate to be 'afterward used for the reproduction of the shape of this sample tool. These formers simply consist of small cast-iron plates in. thick. The chuck which holds the tool can bo rotated in two planes at right angles with each ot her, and the exact amount of rotation in either plane is indieated by graduated circles and verniers, so that any desired angle of tool or of clearance can he aecurately obtained. Poe grinding the curved-face tools, the former plate is first selected and placed in the machine: then the tool to be ground is placed in I he swinging-chuck with h the base of the tool toward the left, and pushed forward against the end gauge until the index-finger of this gauge points to the 1111111h0C given in a table fur nished by the makers, showing the vertical timid horizontal angles which they have found best in riot pmrtniP, plus the animint reqnired to he ground off the tool. The tool is clamped in the chuck and the elmek-swing% so that the entire ellrVe of the tool will rub against t he Nal gauge. The oseillat ion of the index-figure is noted, and the chuck adjusted by means of the handle on the left, until these oscillations are reduced to a minimum. The tool will then be in the best position fur grinding.