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Publication numberUS1703390 A
Publication typeGrant
Publication dateFeb 26, 1929
Filing dateMar 4, 1924
Priority dateMar 4, 1924
Publication numberUS 1703390 A, US 1703390A, US-A-1703390, US1703390 A, US1703390A
InventorsDuffy Peter J
Original AssigneeDuffy Peter J
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1703390 A
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Description  (OCR text may contain errors)

Feb. 26, 1929.

P; J. DUFFY DRILL Filed March 1924 v ljatented- Feb. 26, 1929.


rnrnn J. DUFFY, or nousrou, TEXAS. Y

Application filed March 4, 1924. Serial No. $6,761.

This invention relates. to new and useful improvements in a drill. I

rOne object of the invention resides in the provision of a drill particularly designed .for use in drilling through soft formations, but which may also be used in drilling through rock or other hard formations,

Another object of the invention is to provide a drill of the character described which is of such construction and contour that it will drill a comparatively straight bore.

A further feature of the invention resides in the provision of a drill having a detachable pilot, and detachable side cutters which may be readily renewed in case they become worn or broken.

A still further feature of the invention resides in the provision of a drill having a central spiralled conveyor, so that when the pilot is removed a core will be formed, by the drill, and conveyed up into a core barrel with which the drill is equipped. With the above and other objects in view, this invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawings, where- Figure 1 shows a plan view of the drill.

Figure 2 shows a bottom end view. 1 I

Figure 3 shows a vertical sectional view.

Figure 4: shows a perspective view of one of the side cutters.

Figure 5 shows a side view of the pilot bit.

Figure 6 shows a point view thereof;

Figure 7 shows a side view, partly in section, of a supplemental core conveyor, which may be employed; and Fi re 8 is a plug adapted to be screwed into t e drill head 1, in lieu of pipe 6. 1

Referring now more particularly to the drawings, wherein like numerals of reference designate similar parts in each of the figures, the numeral 1 designates the drillheadwhose upper end is slightly reduced and outwardly threaded to receive the drill collar 2, by means of which the drill is attached to the drill stem (not shown). The head, beneath said collar,

tapers slightly downwardly, or is of an inverted frusto-conical contour. The tapered part of the head has the outside vertical dovetailed grooves 3, spaced a artthere-around. Side'cutters 4, 4 are fitte into these respective grooves, the inner sides of the cutters. being dovetailed to fit into the grooves.

The sides of the grooves, and likewise the sides of the cutters are contracted or converge downwardly and the cutters are fitted into the grooves from the upper ends of the latterand wedge therein. The drill collar 2 is then screwed onto the shank of the drill and its lower end abuts against the upper ends of the cutters and locks them against detachment.

The outer edgesof the cutters are extended forwardly, as at-5, and formed with sharp cutting, or reaming edges, which converge at their lower ends and project some distance below the drill head. The cutters 4 have their cutting edges serrated, the teeth of some of said cutters being staggered with relation to the teeth of the other cutters.

Within the drill stem, and screwed into the upper end of the head, there is a core barrel 6,

of any desired length-whose upper end may be closed in any preferred manner to exclude water or foreign matter and prevent the same from mingling with the core. Aligned with the core barrel there is a vertical bore 7,

through the head, whose walls are .provided with a spiral 8, forming a core conveyor.

the bit progresses through the strata, the projecting lower ends of the cutters 4, 4' form a core which passes up into'the bore 7 and is caught by the spiralled conveyer 8, and car-- ried on upwardly and finally delivered into the barrel 6. The bore 7 is sli htly enlarged upwardly so that the core'wi not bind, or become stuck therein.

. If a smaller core be desired, a supplemental core conveyer 9 may be screwed down- 7 wardly into the bore 7. This conveyer 9 has a vertical bore provided with a. spiral 10,

drill rotates in progress of the work. The

bore 7 and the supplemental conveyor 9 are provided with keyways 7 9 adapted to register when the conveyor 9 is screwed home and to receive a key to prevent the unscrewing of the conveyor 9.

The lower end of the supplemental conveyer 9 is toothed, so as to reduce the size of the core formed by the cutters 4, 4:, in order that the reduced core will enter the con veyer 9. p

When it is desired to use the device as a drill only, a pilot 12 is threadedup into the lower internally threaded end 13, of the bore 7. lhis pilot will hold the drill centered and a straight bore will thus be made. This pilot may be of any desired form. Preferably it is substantially conical in shape, and provided with radiating cutters 14, as shown. The head has the usual water courses 15 to admit flushing water to the cutting edges of the cutters.

As illustrated, the drill is shown with six detachable cutters, but it is to be noted that any desired number may be used, and these cutters may vary in width, so that different iizeg of bores may be drilled with the same When the drill is usedfor takin a core,

particularly in deep drilling, it may e found,

desirable to reduce the bore and this maybe done by removing the cutters altogether. The bearing shoulders, behind the respective cutters are formed with sufiiciently sharp cutting edges to ream out the bore during this core taking process, or very narrow blades may be used, so as'to reduce the bore during the core taking process, to the desired diameter,

It may be further noted that when the drill is not being used as a core taker the core barrel 6 may be removed from the drill head, and

a plug as 16 screwed inthe upper end of said moaeeo head in an obvious manner which will greatly strengthen the drill shank and lessen the liability of its breaking of.

, It is to be further noted that the forward sides of the cutters 4, 4: decline rearwardly or are slightly spiralled relative to the head, so that the cuttings will more readily travel up said declining sides and faces and will not be so liable to congest against the cutters.

It is further to be noted that the cutting edges of the cutters may be inset with diamonds as illustrated in Figure 4, or said cutters may be made of any other hard material desired.

What I claim is 1. A drill including a head, formed with a vertical bore having its inner walls formed into a spiralled conveyor, and approximately vertical side cutters carried by the head whose edges recede toward both ends thereof and, whose lower ends extend below the head.

2./'In a drill, a head having a vertical bore formed into a spiralled conveyor and dove-- tailed side cutters carried by the head, and formed with cutting edges which recede toward each end thereof.

In testimony whereof I have signed my name to this specification.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2520876 *May 13, 1949Aug 29, 1950Koebel Diamond Tool CompanyCore bit
US2657016 *Jan 20, 1950Oct 27, 1953Grable Donovan BFluid circulation head for drill strings
US2803435 *Jun 20, 1955Aug 20, 1957Kammerer Jr Archer WRotary drill bit and stabilizer
US2815933 *Oct 1, 1952Dec 10, 1957Joseph DionisottiDetachable drill bit insert for rock boring tools
US3199379 *Feb 15, 1963Aug 10, 1965Madison Ind IncMethod of manufacturing trepanning head
US3327794 *Oct 16, 1964Jun 27, 1967Creel Ernest SDrill bit assembly
US4790396 *Jun 26, 1986Dec 13, 1988Nl Petroleum Products LimitedRotary drill bits for use in coring holes in subsurface formations
US4953642 *Mar 20, 1989Sep 4, 1990Skaggs Roger DRock drill bit
US5366032 *Jun 9, 1993Nov 22, 1994Kay Mark ARock bit
US6397959May 17, 2000Jun 4, 2002Ramiro Bazan VillarrealMill
US20110013999 *May 19, 2010Jan 20, 2011Hilti AktiengesellschaftDrill
U.S. Classification175/394, 175/413, 175/403, 175/393, 76/115
International ClassificationE21B10/00
Cooperative ClassificationE21B10/00
European ClassificationE21B10/00