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Publication numberUS2224480 A
Publication typeGrant
Publication dateDec 10, 1940
Filing dateOct 27, 1939
Priority dateOct 27, 1939
Publication numberUS 2224480 A, US 2224480A, US-A-2224480, US2224480 A, US2224480A
InventorsJoseph Kartarik
Original AssigneeJoseph Kartarik
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Centering device
US 2224480 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Dec. 10, 1940. J. KARTARIK CENTERING DEVICE' v Filed ot. 2'?, 195s Patented Dec. 10, 1940 UNITED sTATEs PATENT OFFICE CENTERING DEVICE Joseph Kartarik, St. Paul, Minn. Application October 27, 1939, Serial No. 301,665

2 Claims.

This invention relates to an improved centering device for drill bits, and the primary object of the invention is to provide a novel bit attachment adapted to accurately center a hole formed by a bit in a piece of iWork, relative to a countersunk opening in a member attached to the work.

A more specic object of the present invention is to provide a bit attachment of the above kind which may be readily applied to a drill bit, and

which may be eiectively clamped, together with the drill bit, Within the chuck of a brace at a single operation.

A still further object of the present invention is to provide a centering device of the above kind which is simple in construction, durable, and

eiiicient in use.

Other objects of the present invention will become apparent from the following description when considered in connection with the accompanying drawing, inwhich:

Figure 1 is an elevational view of a drill bit equipped with a centering device constructed in accordance with the present invention.

Figure 2 is a longitudinal sectional view thereof taken on line 2- 2 of Figure 1.

Figure 3 is atop plan view of the same; and Figure 4 is a transverse section online @-4 of Figure 1.

Referring in detail to-the drawing, the pres- 3o ent centering device comprises a tubular member through which the conventional drill D is adapted to be directed, and which is preferably composed of an upper section 5 whose lower end is in the form of an internally threaded cap 6. The remaining portion of the upper section 6 is in the nature of a reduced shank l rigid with and projecting upwardly. lfrom the cap portion 6 and split longitudinally at a plurality of points as at 8. The shank l is adapted for reception in:

4 the chuck of an ordinary brace, and by splitting the shank as at 8, said shank is capable of compression under the inuence of the Jaws of the brace chuck for effecting the equipped clamping action of the shank 'l upon the drill D, whereby said drill and the centering device may be locked in the chuck at a single operation.

The centering device further includes an intermediate section 9 in the form of a cylinder having anopen upper end threadedinto the cap portion 6 of the upper section and provided with abottom wall having a 'central opening at I0. The centering device further includes a lower section II slidable through the bottom opening I0 of the intermediate section 9 and having an 55 external annular ange ,I2 at the top thereof (Cl. T1-55) arranged to abut the bottom wall of the intermediate section 9 to limit the downward movement of the lower section II under the iniiuence of a helical compression spring I3 arranged in the intermediate section 9 and having its ends 5 respectively abutting the top wall of the cap portion 6 of the upper section 5 and the upper end of the lower section II. In this way, the lower section lII is yieldingly projected substantially ush with the lower end of the drill D, and 10 the lower end of the lower section II is tapered or of conical form as at I4 to provide a nose adapted to enter the countersunk opening of a member and thereby direct the drill bit D perpendicularly to this member precisely at the cen- 15 ter of the countersunk opening. Thus, when the drill bit D is used to form an opening in the work, such opening will be accurately centered with respect .to the countersunk opening of the member referred to, the lower section II of the 20 centering device receding as the drilling proceeds as permitted by the spring I3; The lower and intermediate sections II and 9 are provided in the sides with openings I5 and I6, respectively to permit the escape of drilling outwardly there- 25 through in case the same should nd their way l into said sections II and 9 of the device.

The present invention will be found of great value when it is desired to fasten a-metal plate onto a backing by screws, which plate is drilled 30 and provided with proper countersinks for the screw heads. AIn order that the screws shall have their heads rest flush with the surface of the plate when they are screwed home, it is necessary that the screws be started exactly in the 35 center of the countersunk hole, as well as accurately perpendicularly to the plate. Otherwise, the head or one side thereof would project above the plate. By means of the present attachment,

' this true centering can be readily and accurately 40 performed without depending upon the skill and vjudgment of thevmechanic. 'I'he device is extremely simple, convenient to use, and efcient. While I have shown what I believe to be a preferred -embodiment of the present invention, it 45 Vwill-be understood that the same is capable of l various modifications and changes in specic details of construction. i y

While the main purpose of the present inven- 50 tionis to center a drill bit as above described; it will be noted that the device acts as a guide which braces the drill bit against deiiection and breakage. Also, by varying the position of the drill bit longitudinally with respect to the device, the latter will act to regulate the depth of drilling. y

What I claim as new is: 1. A centering device for drill bits comprising 'a tubular member through which the drill bit is adapted to be directed, said tubular member comprising an upper section reduced at its upper end to provide a shank, and a spring projected .lower section having a conical lowerV end` providing a nose adapted to enter a countersunk opening with which an opening to beformed by the .drill is adapted to bel centered, said-shank being split longitudinally so as to be capable of compression whereby the centering device and drill may be secured in a chuck at a single operation, said uppersection consisting of an in- 4ternally threaded cap having the shank rigid cap portion and the top of said lower section.

2. A centering device for drill bits comprising a tubular member through which the drill bit is adapted to be directed, said tubular member comprising an upper section reduced at its upper end to provide a shank, a spring projected lower section having a conical lower end providing` a lnose adapted to entera countersunk opening with which an opening to belformed by the drill is adapted to be centered, said shank being split longitudinally so as to be'capable of compression whereby the centering device and drill may be secured in a chuck `at a single operation, said upper section consisting of an internally threaded caphaving the shank rigid with and project- -ing upwardly therefrom, a cylindrical intermediate section threaded into said cap at its upper end and havinga central opening in Ithe bottom thereof through which the lower section slidably projects, said lower section having' an external y annular iiange on the upper end thereof. ar-

ranged to abut the bottom o'f the intermediate Isection to limit the projection of said lowerfsection, and a helical compression spring` arranged in the intermediate section and having its ends respectively bearing against said cap portion and the top of said lower section, said lower and intermediate sections having openings through the sides thereof for the escape of drilling.

- JOSEPH KARTARIK

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2453825 *Jun 20, 1945Nov 16, 1948Wright Samuel BaileyTailstock lathe for drilling
US2547915 *Jul 28, 1948Apr 3, 1951C G S Lab IncGrooving tool
US2612793 *Nov 17, 1950Oct 7, 1952Robert F KrainzHole spacing and centering device
US2788684 *Apr 8, 1953Apr 16, 1957Scharf John HDrilling jig
US2792726 *May 4, 1953May 21, 1957Vick Selmer ESelf-centering bit
US3027785 *Sep 9, 1960Apr 3, 1962Norfolk Products CorpDrill and centering device
US3129614 *Dec 22, 1961Apr 21, 1964Sundstrand CorpTool guide
US4969781 *Apr 7, 1989Nov 13, 1990The B. F. Goodrich CompanyBlind fastener hand tool
US4995434 *Aug 8, 1989Feb 26, 1991Christiansen Clead MWoodworking lathe tailstock assembly
US5507801 *Dec 16, 1992Apr 16, 1996Synthes (U.S.A.)Compression drill guide
US5509762 *Mar 16, 1995Apr 23, 1996Fredricksen; Robert L.Drill bit centering device
US5649793 *May 25, 1995Jul 22, 1997Ericksen; Colin W.Self centering drilling tool
US5779404 *May 11, 1995Jul 14, 1998Jore; Matthew B.Reversible drill/driver tool
US6302409 *Sep 10, 1999Oct 16, 2001Gunter Emil GutscheElements for a magnetic tool holder system
US6488452Aug 2, 2000Dec 3, 2002Vermont American CorporationDrill and drive apparatus having arrangement to accommodate long drill bits
US6761361Aug 9, 2002Jul 13, 2004Credo Technology CorporationDrill and drive apparatus with improved tool holder
US7261499 *Nov 11, 2004Aug 28, 2007The Boeing CompanyAdjustable drill microstop with multiple offset depth settings
US7704257 *Nov 23, 2005Apr 27, 2010Stryker Trauma S.A.Compression instrument
US9095947 *May 22, 2012Aug 4, 2015The Boeing CompanySensing tip reamer
US9610639 *Jul 15, 2014Apr 4, 2017Airbus Operations GmbhHead unit, stop holder and method for stabilizing a drilling machine
US20060099040 *Nov 11, 2004May 11, 2006Mathis Dennis RAdjustable drill microstop with multiple offset depth settings
US20070041799 *Aug 22, 2005Feb 22, 2007Schaefer Robert HTap safety cover
US20070118146 *Nov 23, 2005May 24, 2007Stryker Trauma S.A.Compression instrument
US20150023747 *Jul 15, 2014Jan 22, 2015Airbus Operations GmbhHead unit, stop holder and method for stabilizing a drilling machine
EP0460447A1 *May 21, 1991Dec 11, 1991Synthes AG, ChurCompression drill guide
Classifications
U.S. Classification408/81
International ClassificationB23B49/00, B23B49/02
Cooperative ClassificationB23B49/02
European ClassificationB23B49/02