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Publication numberUS3187825 A
Publication typeGrant
Publication dateJun 8, 1965
Filing dateAug 6, 1963
Priority dateAug 6, 1963
Publication numberUS 3187825 A, US 3187825A, US-A-3187825, US3187825 A, US3187825A
InventorsBower Jr Arnold B
Original AssigneeGen Electric
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Cutter bit for roof drill
US 3187825 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

June 8, 1965 A. B. BOWER, JR 3,187,825

CUTTER BIT FOR ROOF DRILL Filed Aug. 6, 1963 lnven/or: Q Arno/d B. Bower, Jr /5 A k by His Afro/nay- United States Patent 3,187,825 CUTTER BIT FOR ROOF DRILL Arnold B. Bower, Jr., St. Clair Shores, Mich., assignor to General Electric Company, a corporation of New York Filed Aug. 6, 1963, Ser. No. 300,216 1 Claim. (Cl. 175-327) This invention relates to a cutter bit for a roof drill and, more specifically, to a cutter bit and to a cutter bit assembly for use in roof drilling in mines where it is necessary to collect and remove dust and rock particles during the drilling operation.

In the drilling of holes in the roof of a mine for the purpose of installing bolts to be used for the support of the mine roof during mining operations, it is usually necessary to collect the removed material in the form of dust and rock particles to prevent contamination of the atmosphere and its resulting hazards to the miner. The two most widely used methods of dust collection employ suction devices which form an integral part of the composite roof drill. The two devices, commonly referred to as external and through-the-steel types, respectively, and described in greater detail hereinafter, require cutter bits of difierent shank length because the means of attachment of the cutter bit is necessarily located at different positions in the two different systems of dust collection. The result is that two difierent types of cutter bits must be manufactured for the same roof drilling operation. Mining companies which use both types of dust collection units must stock two different roof hits as the miner cannot use the two bits interchangeably.

It is a primary object of this invention to provide a cutter bit which may be used interchangeably in the most common types of dust collecting units in roof drilling.

It is an additional object of this invention to provide a cutter bit assembly having a removable cutter bit which may be securely attached to a drill and efiiciently used in roof drilling, regardless of the particular type of dust collector unit employed.

The invention will be more clearly understood from the following description taken in connection with the accompanyin g drawing in which:

FIGURE 1 is an exploded perspective view of a cutter bit assembly for use in a through-the-steel type dust collection unit illustrating one embodiment of the invention;

FIGURE 2 is an assembled view partly in vertical section of the cutter bit assembly of FIG. 1;

FIGURE 3 is an exploded perspective view of a cutter bit assembly for use in an external type dust collector system; and

FIGURE 4 is an assembled view partly in vertical section of the cutter bit assembly of FIG. 3.

Briefly stated, the invention involves a cutter bit for a roof drill in which the cutter bit shank has a first portion adjacent the head of the cutter bit of polygonal radial cross section and a second portion extending therefrom of reduced radial cross section. Within the polygonal portion of the shank of the cutter bit, there are one or more radial apertures adapted to receive a locking pin for attaching the cutter bit to through-the-steel dust collector units. Within the second portion of the shank, there is an additional aperture to receive a locking pin for attachment of the cutter bit to an external type dust collector.

Referring to the drawing, the cutter bit 1 has a head 3,187,825 Patented June 8, 1965 ice.

portion 2, a shank portion 3 and a flat projecting tang 4. The cutter head may be of any conventional shape ordinarily used for roof drilling in mines. The cutter head illustrated in the drawing has a cemented carbide cutting insert 5 brazed to the inner opposite faces of cutter head 2 so that the insert extends across the body of the cutting head. For square seating on the dust collector, the bottom surface or shoulder 6 is fiat at the plane of attachment of the head to the shank. Shank 3 contains apertures 7 and 8 and tang 4 contains aperture 9. Tang 4 extends along a plane which projects axially and diagonally from two opposite corners of square shank 3. Thus, the tang is at a 45 angle to each of the sides of shank 3. This affords maximum width, and thus strength, for tang 4 without extending its width beyond that of shank 3.

The drawing illustrates the two types of cutter bit assemblies ordinarily used for dust collection in roof drilling operations. The cutter bit assembly of FIGS. 1 and 2 is for through-the-steel type dust collection. Dust collector casing 10 possesses an axial bore 11 of square radial cross section to receive shank 3 and tang 4 of cutter bit 1. Casing 10 is coupled to cutter bit 1 by the insertion of a locking pin 12 through an aperture 13 in the casing and the aligned aperture 7 (or 8) in the shank of the cutter bit. During drilling operations, dust or other removed material is forced by suction into openings 14 located at opposite sides of casing 10 and removed through the hollow interior 15 of the casing and thence through the driving unit to a suitable collection unit.

FIGS. 3 and 4 illustrate an external type dust collector in which dust is collected externally of the cutter bit assembly. Cutter bit 1 is inserted in axial bore 16 in dust collector casing 17 and locked in place by insertion of locking pin 18 through aperture 19 in casing 17 and aligned aperture 9 in tang 4 of the shank of the cutter bit. Helical ledge 20 extends along the external surface of casing 17 for conveying the dust away from the mine roof. A roof drill using an external type dust collection system of this type is shown, for example, at page of Mining Congress Journal, November 1956. In operation, a collar of hollow metal is placed with one extremity at the roof of the mine and is attached at its other extremity to a vacuum device which creates a suction in the collar. The cutter bit assembly of FIGS. 3 and 4 is inserted into the collar. During drilling, the dust is conveyed down the helical ledge and is removed by the suction created between the collar and the cutter bit assembly and suitably collected.

Previous practice required the cutter bit manufacturer i to forge a cutter bit having a shank of suf icient length to receive a locking pin for attachment to an external type dust collector casing (FIGS. 3 and 4). A portion of this shank was then necessarily cut otf for use in throughthe-steel type dust collection in order to allow the free flow of dust into the opening (numeral 14, FIG. 2) of through-the-steel casings. The presentinvention makes possible the use of a single interchangeable cutter bit which may be securely and firmly mounted in a drill, regardless of which system of dust removal and collection is utilized. As can be seen from FIG. 2, the shape of the tang and its manner of projection from the shank of the cutter bit are such that it does not interfere with the entrance of removed material or dust through opening 14 in through-the-steel type dust collector units. Yet, the tang is of sufticient length and strength to enable it to lock securely the cutter bit in' place in external dust collector units as shown in FIG. 4.

What I claim as new and desire to secure by Letters Patent of the United States is:

A removable cutter bit for a roof drill comprising a cutter head and a shank, said shank having a first portion adjacent the cutter head of polygonal cross section and a substantially fiat tang of reduced cross section extending vertically and diagonally from said square portion, said first portion of the shank and said tang each having radial apertures therethrough adapted to receive a locking pin for coupling said cutter bit through one of said apertures to a roof drill.

7 References Cited by the Examiner UNITED STATES PATENTS 10 CHARLES E. OCONNELL, Primary Examiner.


Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2339104 *Jun 10, 1943Jan 11, 1944Central Mine Equipment CoDrill bit
US2578593 *Oct 29, 1946Dec 11, 1951Orville PhippsAuger-type drill bit
US2648525 *Jun 9, 1948Aug 11, 1953Orville PhippsCore-breaking drill bit for doubleflute augers
US3022840 *Mar 19, 1959Feb 27, 1962Mine Safety Appliances CoDust collecting rotary rock drill
US3032129 *May 1, 1959May 1, 1962J H Fletcher & CoDust collecting drill steel and bit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3519091 *Feb 14, 1969Jul 7, 1970Kennametal IncArrangement for drilling in mines
US3554306 *Nov 29, 1968Jan 12, 1971Carmet CoPolygonal drill rod assembly
US3592276 *Apr 28, 1969Jul 13, 1971A M Byers CoRotary percussion drilling apparatus
US3613807 *Aug 14, 1969Oct 19, 1971Galis Alex JDrill rod with dust-collecting means
US4009760 *May 6, 1976Mar 1, 1977Carmet CompanyApparatus for roof drilling
US4019590 *Oct 1, 1975Apr 26, 1977Carmet CompanyMethod of roof drilling
US4086972 *Jan 21, 1977May 2, 1978Carmet CompanyMethod and apparatus for roof drilling
US4165790 *May 30, 1978Aug 28, 1979Fansteel Inc.Roof drill bit
US4189013 *May 18, 1978Feb 19, 1980Gte Sylvania IncorporatedRoof drill bit
US4190125 *Nov 9, 1977Feb 26, 1980Fansteel Inc.Drill bit and steel combination for improved fluid flow
US4190128 *Dec 21, 1978Feb 26, 1980Fansteel Inc.Roof drill bit with hexagonal body portion
US4398611 *Feb 8, 1982Aug 16, 1983Gte Products CorporationMining drill
US4488609 *Feb 8, 1982Dec 18, 1984Gte Laboratories, Inc.Mining drill
US4632195 *Jun 3, 1985Dec 30, 1986Fansteel Inc.Roof drill system
US4702328 *Nov 22, 1985Oct 27, 1987Mcsweeney Lawrence HRoof drilling system
US5492187 *Nov 18, 1994Feb 20, 1996Hilti AktiengesellschaftTwist drill
US5782310 *Apr 10, 1996Jul 21, 1998Lange; James E.Dry hollow stem augers
US6598688Jul 16, 2001Jul 29, 2003John WangDrill steel for drilling mine roofs and associated method of drilling bores
US6868924 *Mar 22, 2001Mar 22, 2005Hawera Probst GmbhRock drill
US6886645May 30, 2002May 3, 2005Kennametal Inc.Liquid seal for wet roof bit
US8800613 *May 10, 2011Aug 12, 2014Stuart Batty Enterprises, LlcFluted woodturning tools with handles
US20120006448 *May 10, 2011Jan 12, 2012Stuart BattyFluted woodturning tools with handles
DE2548637A1 *Oct 30, 1975Sep 16, 1976Carmet CoVerfahren und vorrichtung fuer bohrarbeiten im deckgebirge
U.S. Classification175/327, 175/320, 175/323
International ClassificationE21B10/44, E21B10/00
Cooperative ClassificationE21B10/44
European ClassificationE21B10/44
Legal Events
Mar 15, 1982ASAssignment
Effective date: 19820216