Note: Descriptions are shown in the official language in which they were submitted.
12403~
Monologue loyalty
BACKGROUND Ox rule ~NVENIION
1. Field of toe Intone
The present Invention relates generally to
improvements in the urn ox rock drilling undo in
particular the present invention reputes to us improved
mining drill bit.
Descr~et~on__t_the Purl rewrote
In drilling into rock such as In mine drilling
it is conventional to use u hard carbide cutter insert
mounted upon a holder which in turn Is fastened to the
end of a hollow tubular shift which is powered for rout-
lion. Tile suit is collventionlllly provided with openillgs
near the holder so that the dust my be removed by
applying a vacuum to the opposite end of the hollow
shrift. In drills of this type if is desirable to locate
the dust collecting openings as close us possible to the
cutter insert in order to promote efficient operation and
to Insure an efficient and rapid removal of the dust.
Prior art mining drill bits ore disclosed In United
States Letters Patents No. 3 163 246 and No. 3 43q 553.
The mining drill bits disclosed in these patents are pro-
voided with some type Or opening at the end Or the drill
bit which is disposed in communlcution with the hollow
interior Or the drill bit shaft for debris removal. In
both of the aforementioned patents bores ore termed ill
the end of the drill bit on opposite sides of the cutter
insert. In the prior art design the bores are of air-
culsr cross section and disposed at a predetermined unglue
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ilk respect to the lollgltudinul cutting Uris of the
drill. The prior art dril!-blts require u number of
cutting operations in order to tory the finished product
and sure relatively expensive to manufacture.
It Is believed tout two posltlonlng of the
openings near the head of the holder for the purpose of
rennoving dust and other debris Is critical to the opera-
lion of such mine drilling bits, undo it has been
Applicant s discovery that drilling bits of the prior art
having such openings tend to become clogged. This is due
to their locution with respect to tile gutter insert end
the size of such openings. Many of the prior urn cutters
lluvc nil opening which extends of right angles to tune
cutter insert and fins n tendcllcy to clog nod prevent the
further withdraw of debris, resulting In high Tories
acting on the mining drill bit and a failure of the drill
bit or the shaft driving two bit.
It would therefore be dcsirnble to have a mining
drill bit which Is ox a simple design and which obviates
the disadvantages and objections nttendnnt the prior art
designs.
SUMMARY OF TIRE INVENTION
_______________ ____
The present invention, witch will be described
subsequently In greater detail, comprises Q mining drill
bit tint has a circular body with u longitudinal bore
extending in trot one and while the other end defines the
head of the drill bit and Includes a prowler ox Intersecting
slots arranged dlnmetrlcally transversely of the longltu-
Donnelly axis of the body. On of two slots receives n
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cutting insert while the second slot, which is preferably
disposed at a 35 angle with respect to the first slot,
provides a simple and efficient means of removing debris
created as a result of the drilling operation.
In summary, therefore, the present invention may
be broadly defined as providing a mining drill bit
comprising a circular body having a longitudinal bore
extending from one end of the body a predetermined distance
: along the longitudinal axis of the body, the other end of
the body defining the head of the bit and having a first
slot arranged diametrically transversely of the
longitudinal axis of the body wherein the first slot is
adapted to receive and securely support a cutting insert;
the head having a second slot arranged diametrically
transversely of the longitudinal axis of the body and
extending inwardly into the head a sufficient distance to
communicate with the longitudinal bore, the second slot
intersecting where first slot at an angle substantially
less than 90, wherein the drill bit is adapted to receive
and be supported by a shaft for rotatable driving the drill
bit and wherein a vacuum may be applied to the end of the
drive shaft opposite the drill bit; the second slot and
bore being sized for rapid withdrawal of debris created by
the drilling operation to permit the debris to pass from
the drill bit to the bore.
B Other features, advantages and applications of
the present invention will become apparent to those skilled
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- pa -
in the art of mining drill bits when the accompanying
description of one example of the best mode contemplated
for practicing the invention is read in conjunction with
the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAYING
The description herein makes reference to the
accompanying drawing wherein like reference numerals refer
to like elements throughout the several views, and wherein:
FIG. 1 is an exploded, front elevation Al view of
a mining drill bit constructed in accordance with the
- principles of the present invention;
:;
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Fly. 2 is n top e~evntlonal view of the mining
drill bit as seen from fine 2-2 in FIX. I;
FIG. 3 is n rent elcvntiollul view ox the mining
drill bus Illustrated in Fly. 1 with tile cutter insert
removed for clarity; nod
YIP. 4 Is n bottom elevntional view of the
mining drill bit BY seen from lion 4-9 ox FIX. 3 nod
rotted 90.
DESCRIPTION OF Tile PltEFElUlED EMBOVlMEiT
lleferring now to the drnwine undo in psrticulur
- to Flask I nod 2 there Is Illustrntcd one oxnmple Or the
present invention In the form of mining drill bit lo.
Tao mining drill bit 10 is ox n ullitllry construction
hiving n cyllndricnlly shaped body 12 which in the
IS example Illustrated his n dinmcter of Lucy Inches nod n
longitudinal length of 2.2 inches. The lower or shank
portion 14 of the cylindrlcnl body 12 his a hexagonally
shaped bore 16 tint extends npproxlmntely l.ZS Inches
Into the Interior of the body from the shank end 14
thereof. The bore 16 his a pair of longltudlnslly spanked
undercuts 18 sod 20 (FIG. I the purpose of which will
be described herelnnfter. Tile shank bore 16 Is sdnpted
to receive the tubular shift 17 which rotntnbly drives
the mining drill bit 10. The mining drill bit 10 Is
I secured to the tubular shift 17 by mcnlls of n set screw
(not shown tint extends through rndlnl bore 22 (see
PIGS. 3 nod 4) nod engages the tubular shift 17 in the
conventions! mnnller.
.
I
The hued 24 of the monologue drill bit 10 18
slightly truncated undo in¢ludos n first longitudinally
transversely disposed slot which it npproxlmntely .2
inches in width undo extends the full diumctricnl width of
the head 24. The slot 26 Is approximately .56 inches In
depth nod Is adopted to recGlvc n gutting element or
insert 28. The gutting element or Insert 28 Is convent
tonal In Its construction sod Is secured within the
diametrical slot 26 In a suitable manner, such as by
IT soldering, brazing or welding, so tint the cutting eye-
mint 28 has u conventlonnl Impact portion extending above
the hind 24 of the mlnlnE drill bit 10.
The mining drill bit 10 Is further provided with
- n flushing opening, the plncoment undo tormntlon ox the
opening being extremely importQI~t in prolonging the Lowe
of the bit 10 nod the gutting Insert 28 cnrrled thereby.
To form the flushing openings, Q second dlnmetrlcnl slot
ED Is formed In the hind 24. As gun best be seen In ala.
2, the slot 30 Is approximately 25 Inch wide, 1.00 inch
deep and extends the full dlametrlcnl width ox the
gutting head 24 Intersecting and pnsslng through the
gutting element slot 26 at an angle "A" between 32 nod
38, sod pre~ernbly 35- In mnnufncturlng the mining
drill bit 16v, the slots 26 end 30 arc simply formed by
first gutting one diametrical slot In one puss over the
hued 24 of the~blt 10 end than forming the second slot us
the desired width sod depth. This very simple construe-
lion sod method ox nisnufQcture results In n drill bit
which is substnntlnlly less expensive to mnnurncture than
I
.
-" Lotte
the prior art devices all provides excellent results in
operation. In operation debris nod dust that is formed
during the drilling operation will communicate with the
tubular portion of the drive Shinto 17 via the diametrical
slot 3û end the interior of two boron ox the shank bore
16. To further fucllltate the removal ox debris and
dust udditlonal space for the p~ss4ge of debris is pro-
voided by the undercuts 18 end 2ii hcrelnbefore described.
In operetlon when the drill is operated in rock
u vacuum may be applied to the opposite and of two drive
shaft 17 to suck in through the transverse slot 30 and
the shank bore I the dust-laden air and the like
thereby cloning the drill hole nut the cutter insert
which results in n longer life tar tile insert undo the
1 mining drill bit Tao
It should be understood by those skilled in the
sot ox mining drill bits that other forms of the present
Invention my be had all coming within the spirit of the
invention and scope of the appended claims.
