US2734725A

US2734725A - Ctatfs patfnts

Info

Publication number: US2734725A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

INVENTOR. ROBERT H. HOLSING QMQW United States Patent ROCK DRILL BIT Robert H. Holsing, Canton, Ohio, assignor to The Timken RfOgltEII: Bearing Company, Canton, Ohio, a corporation 0 10 Application March 3, 1950, Serial No. 147,430

1 Claim. (Cl. 255-64) This invention relates to rock drill bits and is more particularly directed to an integral pivotal or flexible washer for holding the bit on a polygonal sectioned drill rod.

The object of the invention is to provide a replaceable bit for rock drills having pivotal or flexible integral griping portions thereon adapted to frictionally engage the drill rod to which they are removably secured.

The invention consists in the provision of a rock drill bit to be installed on a polygonal sectioned drill rod and in which the sides of the drill bit are slashed or slotted to form integral pivotal or flexible washer portions there on prior to the hardening of the drill bit which also imparts spring properties to the washer portions and, upon being moved relative to the drill bit, will grip the drill rod inserted therein.

The invention also consists in the forming of integral pivotal or flexible washer portions on the collar of a rock drill bit for imparting resilient qualities to the washers while hardening the body of the bit.

The invention further consists in the parts and combinations and arrangement of parts hereinafter described and claimed.

In the drawings:

Fig. l is a side elevational view of a drill bit embodying the invention,

Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1,

Fig. 3 is an end view of a different form of the invention,

Fig. 4 is a sectional view taken substantially along the line 4-4 of Fig. 3,

Fig. 5 is a side elevational view of another modified form of the invention; and

Fig. 6 is a sectional view taken substantially along the line 6-6 of Fig. 5.

The invention is embodied in the structure illustrated in the several views of the drawings in which the numeral 1 designates a drill bit body provided with cutting edges 2. A bore 3 is provided in said body, thereby forming a collar portion 4 thereon. The bore is polygonal in section so that relative rotation between a similarly sectioned drill rod 5 inserted therein, is prevented.

A slot 6 is cut in the collar portion and the metal at the base of the cut is relieved by drilling a hole 7 therein. The slot is cut at an angle less than 90 to a plane through the collar portion extending at right angles to the longitudinal axis of the drill bit body. The slot extends to a point within the semi-circle of the collar portion on which it is cut. The drill bit body is then heat treated to harden it and to impart resilient properties to the partially severed washer portion 8 which adapts it for pivotal or flexing motion relative to the bit body, the partially severed portion being bent inwardly prior to heat treating so that the bore of the partially severed portion is not in exact alignment with the bore of the collar portion. The bore of the washer portion is relieved so that when the portion is pivoted or flexed outice wardly, it will be in substantial alignment with the bore 3. The drill rod 5 can then be inserted in the bore. The drill rod is held in the bore by reason of the fact that the inward pivoting or flexing washer portion causes a corner or curved edge thereof to frictionally engage a longitudinal corner of the drill rod and, during use, the vibrating action of the drill rod and bit causes the said corner or edge of the washer portion to be imbedded in the rod at the corner or corners thereof, depending upon the shape of the drill rod. The drill rod may be withdrawn from the bore after pivoting or flexing the washer portion outwardly relative to the drill rod so that it will be disengaged therefrom, which action will permit the bit and drill rod to be separated.

Figs. 3 and 4 illustrate a construction similar to that shown in Figs. 1 and 2, except that the severed portion 8 is crimped so that the slot diverges outwardly. The bit is then heat treated for the purposes set forth above. The washer portion 8 has its bore suitably relieved so that when an outward pivotal or flexing motion is imposed thereon, the drill rod 5 may be inserted in the bore. The washer portion overlies the bore in the collar. After its release, a corner or gripping edge of the washer portion engages with and imbeds itself in a corner or corners of the drill rod. The drill rod is removed in the same manner as described above. The form of bit shown in Figure 4 has a larger relief angle in its bore, this being necessary because of the outwardly diverging slot 6.

The bit and rod are separated in the manner described above.

Figs. 5 and 6 illustrate a modified form of the invention in which the numeral 9 designates a drill bit body having cutting edges 10 thereon and provided with a bore 11 of polygonal section. This bore receives a similarly sectioned drill rod 12.

The drill rod is held in the bore by washer portions 13 formed by cutting slots 14 in the collar 15. Holes 16 are cut in the collar 15 at the base of the slots, thus relieving the strain on the collar metal when washer portions 13 have pivotal or flexing motion imposed thereon. The slots 14 are cut at right angles to the longitudinal axis of the drill bit body. The washer portions are then bent axially from the body for diverging the slots outwardly and causing them to overlie the bore 11. The bore of the washer portions is relieved so that a corner or edge thereof can engage and imbed itself in a corner or corners of the drill rod. Thereafter the drill bit is heat heated for hardening and simultaneously imparting resilient properties to the washer portions. The drill rod is inserted in bore 11 after imposing an inward pivotal or flexing motion on washer portions 13. The relieved bores in the washer portions 13 and the bore in collar 15 are in substantial alignment when the washer portions are moved inwardly relative to the bit body. The drill rod is held in the bit bore by the overlaid washer edge portions gripping said drill and vibration of the bit body and drill rod causes said edge or corner of these portions to become imbedded in the drill rod. The drill rod and bit are separated by applying an inward force to the washer portions, thus forcing them away from the drill rod toward the collar of the bit body. This action re-aligns the bore in the collar and in the washer portions, thereby permitting separation of the bit body and the drill rod.

What I claim is:

A drill bit adapted to be detachably connected to a drill rod; said drill bit including a body having cutting edges on its forward portion and a rearward collar portion having a drill rod receiving bore, said collar having a transverse narrow slit extending therethrough and partially severing a substantial portion of the collar thereby forming a resilient collar portion, said collar portion being normally bent to provide a bore portion normally out References Cited in the file of this patent UNITED STATES PATENTS 5 188,055 Johnson Mar. 6, 1877 678,629 Smith July 16, 1901 726,388 Wysong Apr. 28, 1903 822,313 Stevens June 5, 1906 1,760,113 Brown May 27, 1930 10 4 .Noxley ..M. ..-V.- June21, .1932 Hickman Nov. 15, 1932 Murphy June 24, 1941 Busse Apr. 14, 1942 Padley et a1 May 4, 1943 Gascoigne Dec. 21, 1943 Turner Aug. 22, 1950 OTHER REFERENCES Mechanical Engineers Handbook, Marks, 5th edition.