(Model.) 2. Sheets-Sheet 1. J. BIRKENHEAD, MECHANISM FOR SUPPORTING AND GUIDING DRILLS WHILE BEING GROUND, No. 327,758, Patented Oct. 6, 1885,

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(Model.) 2 sheets-sheet 2. J. BIRKENHEAD. MECHANISM FOR SUPPORTING AND GUIDING DRILLS WHILE BEING GROUND. No. 327,758. Patented 00t, 6, 1885,

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N, PETERs, Photo-Lithographer, Washington, C. C.

UNITED STATES PATENT OFFICE.

JOHN B I. R. KEN HEAD, OF MANS FIELD, MASS ACHU SETTS. MECHANISM FOR SUPPORTNG AND GUIDING DRILLS WHILE BEING GROUND,

S321:CIEICATION forming part of Letters Patent No. 327,758, dated October 6, 1885. Application filed September 19, 1883. Serial No. 106,796. (Model.) To a 2Z Zuhon, it inval/ conce772, : prevent end wise motion of Said journal in its Be it known that I, JoHNBIRKENHEAD, of bearing. This bearing f has a journal, h, ex Mansfield in the county of Bristol, of the tending down from it into a post, i, also made Commonwealth of Massachusetts, have invent so as to be capable of being clamped to the ed a new and useful Improvement in Mech journal by a screw, k. This post extends up anism for Supporting and Guiding a Twist or ward from a base, l, having appliances for fiX Angularly Pointed Drill while in the act of ing it on the trough of a grindstone in a being Sharpened by a Grindstone; and I do manner to enable the tool-rest to be brought hereby declare the same to be described in the into a suitable position relatively to the stone following specification and represented in the for a drill to be ground or sharpened thereby. O accompany drawings, of which The devices described for supporting the Figure 1 is a top view, Fig. 2 a front eleva tool-rest admit of it being turned horizontal tion, and Fig. 3 a side view, of mechanism ly and vertically for adjusting and moving a embodying my invention, the nature of which drill for the grindstone to grind it to the prop is defined in the claims hereinafter presented. er inclinations at its angular cutting end. By Fig. 4 is a longitudinal section, and Fig. 5 a. Such devices the tool-rest can be raised or de transverse section, of the adjustable clamp or pressed, as the size or diameter of the drill to pivot carrier, the eccentric sleeve thereof and be sharpened may require, in order to bring the tubular spindle of the adjustable tool-rest the part to be ground into its due relation to to be described. Fig. 6 is a top view of the the stone for such part to be ground convex disk B and its journals b and c. Figs. 7 and rather than concave. S are drawings illustrative of two methods of Drills for boring into metal, specially what curving the edges of angularly-pointed drills. are termed “twist-drills,' usually have an Fig. 9 is a front end view of the tool-rest. Fig. angular cutting end, each of whose two bevels 75 10 is a top view, and Fig. 11 a side view, of it is desirable to have somewhat convex rather 25 parts of a grindstone and its trough with a than flat or concave transversely of it. If in twist-drill and its Sustaining mechanism, as grinding the drill by a grindstone such drill hereinafter described, applied to it. Fig. 12 be moved rectilinearly forward against the is an end view of a twist-drill, showing its cut periphery of the stone, it will be seen that the ting-edges. reduction of the end of the drill Will neces In the said drawings, A. denotes the tool sarily be more or less concave; but to give rest, it having on and through it, to receive greater strength to the drill at its cutting the tool, a groove, ct, right angular in its trans edges it is desirable and it is customary, espe verse section, such rest being Supported on cially with a twist-drill, to grind it convexly 8 5 and clamped to the journal b of a disk, B. to each cutting-edge, as shown at at in Fig. This journal b projects from one side of the 7, rather than concavely, as shown at b in disk concentrically with the circumference Fig. 8. of the disk. From the opposite side of the The object of having the tool-rest sustained disk another journal, c, extends eccentrically by the journal c and its bearing is to enable to the said circulaference. such rest, while a drill supported on it is be The tool-rest A. can turn on the journal b, ing ground, to be turned, so as to cause the the part e, encompassing such journal, being ground part to be reduced convexly vertically, contractible or constructed So as to be capa as shown in Fig. 7, whereby the cutting part ble of being clamped to the journal by a screw, is rendered stronger than it would be if con 95 d, properly adapted to such part. The longer cave, as shown in Fig. S. 45 journal c turns in and is supported by a From the tool-rest a tubular cylindrical bearing, f, contractible or constructed so as to shank, C, projects in manner as shown, it be capable of being sprung and clamped to going through a cylindrical sleeve, D, whose the journal by a screw, g. A screw, u, is bore is eccentric relatively to the periphery ICO screwed through one side of the bearing fand of such sleeve. The sleeve is sawed or Split into an annular groove, , in the journal c, to lengthwise to enable it to be clamped on the

327,758 shank by a Screw-clamp, E, encompassing the low the said journal b. (See Fig. 11.) The sleeve and provided with an ear, m, extend screw d should now be tightened, so as to ing from it, (the said clamp), as represented. firmly hold the bearing e from turning in its Through the said ear a pivotal screw, F, is journal b. The bearing f should also be made, Screwed. A twist-drill is shown in dotted by the screw g, to firmly bear on the journal lines at G in Fig. 1 and in full lines in Figs. c, so that it will not turn too easily thereon. 10 and 11, as in the rest, and supported at its The cutting-edge of the drill to be ground rear end by the said pivotal screw, whose should stand in a horizontal position or par conical end enters a like centering-recess in allel to the axis of the stone, and the gage L. 75 O the end of the shank of the drill. should be adjusted by means of the screw M. By revolving the sleeve D the clamp can to bear against one edge of one of the spiral be moved so as to bring the screw F nearer grooves of the drill. (See Fig. 10.) The grind to or farther from the shank C, as the size of ing of the drill can now be proceeded with. a drill to be ground may require; and besides The grindstone being in revolution, the drill this the clamp can be turned on the sleeve, should be advanced by the screw F to bear So as to further adjust the screw in order for tightly against the stone by the attendant, it to properly sustain the drill. By revolving who is supposed to hold the drill against the the screw F the drill can be advanced toward screw F with his right hand and the shank and against the stone. C in his left. The dotted lines in Fig.11 rep There extends through the shank C a rod resent a drill as it appears in the said opera or shaft, H, having projected from it at its tion, one of its lips being ground, the cutting end next the tool-rest an arm, I, formed as edge of said lip being in a horizontal position shown, the shaft at its other end being pro or parallel with the axis of the stone, 1 rep vided with a prismatic head, K. On apply resenting the lip that is being ground in Fig. ing a Wrench to the said head and turning it 11 and diagrammatically in Fig. 12, and 2 the arm I may be turned down upon or off the that which is shown by the same number in drill as occasion may require, the purpose of both figures. The shank is now to be raised the said arm being to hold or aid in holding and lowered vertically. That part of the drill the drill down within the rest by means of which comes in contact with the stone during 3O power applied by the hand of the attendant said movements will of course be removed. to the said Wrench, said holding mechanism The drill is again to be advanced by the screw being for use in the grinding of drills of small F and the shank raised and lowered again, diameter. Furthermore, there is adapted to and this operation is to be continued until ICO the tool-rest an adjustable gage, L, which is that part of the end of the drill shall have particularly shown in Fig. 9 as arranged been properly ground. As the shank C is against its front end, and provided with a raised the tool-rest will turn on its axis c, and screw, M, for adjusting it nearer to or farther when the drill reaches the position shown in from the bottom of the said rest, as thesize of full lines lip 1 will have been carried past the drill to be ground may require. This gage is nearest point of the stone and have received -4) to extend into one of the spiral grooves of the the shape shown in full lines in Eig. 11. The drill and against one edge thereof, in which shank c should now be lowered, and the drill case the gage determines the position of the turned on its axis, or so as to bring lip 2 into part to be ground, and enables an attendant to the position previously held by lip L. Now, IO at once turn the drill to bring such part into on raising the shank c, as before, lip 2 will be its correct position. ground to the same shape as lip 1. The drill In Figs. 10 and 11 a grindstone in part is is now to be revolved on its axis one hundred shown at S and its water-trough at T. In the and eighty degrees of a circle, and the other said figures the basel of the twist-drill sup part or bevel of the end of the drill is to be porting mechanism is represented as arranged operated upon in like manner as the preced II5 on and clamped to the said trough, a drill be ing one. The purpose of having the two jour ing exhibited as duly applied to the mechanism nals b and c is to admit of the tool being raised and the Stone. or lowered as may be necessary for the grind The operation of grinding a drill may be ing of drills of different sizes, it being desir thus described: The front or cutting end of the able to have the axis of the drill, when in the drill is to be placed in the rest A, and the cen rest and in a horizontal position, as shown in tering hole or recess in the rear end thereof is Fig. 11, a little below the journal c, on which to receive the conical end of the screw F, (see the tool-rest swings in the operation of grind Fig. 10,) which should and can be adjusted by ing, in order that the end of the drill, when means of the sleeve D, so that the drill will ground, may have the desired convexity, said I 25 bear evenly in the rest. Said adjustment hav. convexity being the arc of a circle whose cen ing been effected, the sleeve should be con ter is in the axis of the journal c, produced. fined to the shank C by the clamp E. The (See Fig. 11.) This invention is applicable to clamp-screw d should now be loosened, and the drills having cutting-edges of any shape, as journal c turned by the aid of a wrench ap well as the kind specifically shown. plied to the prismatic part thereof, so as to I claim raise or lower the journal b, as may be neces 1. The tool-rest, substantially as described, sary to bring the axis of the drill a little be in combination with mechanism for support.

327,758 3 ing it and adjusting it vertically and horizon shank C, all being arranged and adapted to tally, and allowing of it being turned, essential operate in manner substantially as set forth. ly as set forth, such mechanism, as described, 3. The combination of the tool-holding arm consisting of the tool-rest clamp e d, the disk I and its carrying-shaft H with the tool-rest I5 B and its journals b and c, the clamping-bear A and its shank C, all being adapted and ar ing f, and its screw g and journal h, and the ranged substantially as set forth. clamping part i and its screw k, arranged and adapted as represented. JOHN BRKENHEAD. 2. The combination of the pivotal screw F, Witnesses: IO and its clamp E, and the eccentric and con R. H. EDDY, tractile sleeve D, with the tool-rest A and its E. B. PRATT.