US669764A - Guiding appliance for drills. - Google Patents

Description

No. 669,764. Patented Mar. [2, I90I. M. POTTER. GUIDING APPLIANCE FOR DRILLS.

(Applicaticn filed Nov 27, 1900.)

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MORGAN POTTER, OF FISHKILL-ON-THF-HUDSON, NEW YORK.

GUIDING APPLIANCE FOR DRILLS.

SPECIFICATION formingpart of Letters Patent No. 669,764, dated March 12, 1901.

Application filed November 2'7, 1900. Serial No. 37.889. (No'modelJ To all whom it may concern.-

Be it known that I, MORGAN POTTER, a citizen of the United States, residing at Fishkillon-the-I-Iudson, county of Dutchess, and State of New York, have invented certain new and useful Improvements in Guiding Appliances for Drills, of which the following is a full, clear, and exact specification, reference being had to the accompanying drawings and to the letters of reference marked thereon.

My invention relates to drills, especially of the class employed for perforating metal, and preferably to the kind known as twistdrills, although my improvements may be found useful in connection with metal-drills of other kinds.

The object of my invention is to provide or supply metal-drills with reliable and effective appliances whereby the drills will be enabled to be used for accurately following or reboring a perforation already made in the metal, so that the new perforation will be exactly and accurately in line with the first and the drill prevented from dancing, chattering, or cutting out of true line.

To accomplish the foregoing object and to secure other and further advantages in the matters of construction, operation, and use, my improvements involve certain new and useful arrangements or combinations of "parts and peculiarities of construction, all of which will be herein first fully described and then pointed out in the claims.

In the accompanying drawings, forming part of this specification, Figure 1 is a View in elevation of myimproved appliances constructed and arranged for operation in accordance with my invention and assembled as for use, indicating in dotted lines the manner of applying a pair of ordinary calipers in order to guide the operator in the operation of sharpening the drill. Fig. 2 is a section and elevation on a plane through line m w of Fig. 1, showing the drill-guide in elevation. Fig. 3 is a plan view of one of the drill-guides detached from the drill, the cylindrical portion of the guiding-block being smaller than in previous figures to indicate that this portion may be of, any diameter smaller than that of the drill, but larger than that of the shank of the guiding-block. Fig. 4 is a view similar to Fig. 3, but showing the guidingcylinder of diameter same as that of its shank.

In all the figures like letters of reference, wherever they occur, indicate corresponding parts.

A is the body of the drill, preferably of the form known as twist-drill, but under some circumstances other forms of drill might be substituted for this one or my improvements applied in connection with other forms. The shank of this drill a is shown as cylindrical and adapted to be received and held by any suitable form of chuck; but it may be fashioned otherwise than indicated in the drawings. The drill is perforated axially through and through, a portion of this perforation I) being smaller in diameter than the remaining portion, leaving a square shoulder, as at c, at about the region of the union of the shank of the drill with the other part.

B represents the cylindrical portion of the guide, the same being formed with or applied on a shank O, which shank is fitted to closely occupy the larger portion of the bore through the drill and is of a length to abut against the shoulder c and hold the inner face of the cylindrical guide B a very trifle away from the cutting lips of the drill-say-. a sixtyfourth of an inch-so that the cutting-lips will not be damaged or dulled thereby. The cylindrical shank O is planed off or cut away for nearly its entire length, leaving a narrow flat surface d, against which the end of the settingscrew bears to keep the shank and guide from turning or moving from the seat provided for it when the drill is at work.

D is the securingbolt, which is tapped through the body of the drill at a point well back from the cutting-lips, so that the drill may be ground away practically for its entire length.

The outer extremity of the guide-cylinder is slightly beveled, as indicated at 6, so as to facilitate the insertion of the guide in the drill-hole that is to be followed without difficulty and without damaging the perforation or the guide.

In Fig. 4 the cylindrical guide at Binstead of being of greater diameter than the shank C is of the same diameter, so that it may be entered in a smaller perforation. In this on the side toward the cutting-lips.

form the inner extremity of the cylindrical guide instead of being located a trifling distance outside the limit of the cutting-lips should be located a corresponding distance within the limit of these lips.

From the foregoing it will be seen that I propose to employ these guides of any required or desired size from the diameter of the bore up to that of the drill. They are preferably of hardened steel,so that they cannot be worn by turningin the metal, as they must do while the drill is revolved, and they are smooth on the exterior, so that they cannot enlarge the opening as the drill progresses, but will compel the drill to follow accurately in the axis of the opening.

These guides are employed in cases where accurate work is necessary or desired. It is well known that ordinary metal drills following in a perforation already made will naturally bear toward one point or another as the variations in the metal will compel or permit or as the condition of the cutting edges will compel or permit, and this is obviated by myimproved guide.

It will be observed that the perforation through the drill is smallerin diameter than the smallest portion of the drill, so that the grooves are not cut through to the weakening and damage of the drill. The purpose of perforating the drill throughout its length is to permit the insertion of a drift at the back of the drill to drive out the shank 0 when it is necessary to remove it for inserting a new or different guide or for grinding the drill, and to prevent accumulation of foreign matters within the perforation, and to facilitate cleaning the perforation.

To facilitate gaging, I supply the drill with a groovef, leaving a square or plain face 9 This face being turned perpendicular to the axis of the drill operates as a guide for one point of a pair of caliperssuch, for instance, as represented in dotted lines at E in Fig. 1the other point of the calipers being made to determine the proper location of the extremity of the cutting-lip, but the groovefand plain face 9 may be omitted.

In grinding the drill of course the guide B or B must be removed. After the drill is ground the inner end of the shank C should be correspondingly cut away or ground off, so that when the end abuts against the shoulder 0 the guide B or B will be in proper location. It is for this reason that the plain surface 01 extends about the length of the shank 0; otherwise when the end of the shank is ground away the upper surface of it would also need to be ground.

I am aware that it has heretoforebeen proposed to locate a second twist-drill within a larger drill for the purpose of operating in conjunction-that is, so that in boring the first drill would cut a small perforation while the larger one is cutting a larger perforation. Such a drill requires that the outer drill be cut through the grooves, and, besides, the smaller drill could not operate as a guide after the manner of my improvement, for the reason that the edges of the grooves would cut and enlarge the first perforation, and thereby defeat the accurate boring of the larger perfo' ration, as is accomplished by my invention.

My improved appliances constructed and arranged as above set forth are found in practice to admirably answer the purpose or object of the invention hereinbefore alluded to. Involving nothing but circular work, they are easily, cheaply, and accurately made, and they are durable and efficient without interfering with the complete utilization of the drill.

Having now fully described my invention, what I claim as new herein, and desire to secure by Letters Patent, is

1. The herein-described cylindrical guide for drills, the same being provided with a shank and combined with a drill having an axial perforation smaller in diameter than the smallest part of the drill and extending throughout its length, said perforation being smaller in diameter at one portion than at the other, leaving aninner shoulder against which the said shank abuts, substantially as shown and set forth.

2. The herein-described cylindrical guide for drills, the same being provided with a shank having aflattened or cut-away portion as explained and being combined with a drill having an axial perforation, an inner shoulder, and a setscrew for holding the shank, substantially as shown and set forth.

3. The herein-described cylindrical guide fordrills, the same being provided with a beveled extremity and a shank having a flattened portion and combined with a drill having an axial perforation extending throughout its length, an inner shoulder againstwhich the shank of the guide abuts, and a set-screw for holding the shank, substantially as shown and set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

MORGAN POTTER.

Witnesses:

M. E. CURTISS, THOMAS ALDRIDGE.

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