Note: Descriptions are shown in the official language in which they were submitted.
21 99579
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"ROTAI~Y ROCK DRILL"
BACKG~OUND TO THE Il~ENT~ON
THIS invention relat~s to a rotary rock drill.
Rotary screw feed Ai~nn~ drills are used w~dely for drilling rock in
ul~de.g~vulld miIles. A typical e ~'- of a known screw feed ~ m~
iS ill..~n.,t.~ res 1 and 2 ofthe ~ec .~ ,ji~ d~c~w~gs. The dr~ll has
a hollow r~,~ o carrying a ch~k 12. A drill rod 14 ~vith a diamo~d
bit 16 at its leading end passes tbrough the r~ . 10 and is gripped by
the chuck 12. All air motor 18, typicaUy a vane-type r~ motor. is
mr-nnt~rl on a casing 19 and is driven by com?~d air. The motor drives
a gear 20 which meshes w~th a gear 22. The gear 22 is fast on a shaft 24
which also carnes anot~er gear 26. The gear 2~ meslles with a gear 28
v-~t~,d on ~ quill 3~ which has inwardly directed splines or keys 32 that
engage ~n grooves or keyways 34 in the r~JS~ o, allowing dle
. to slide forwardly~ in ~e ~lir~, Liwl indicated by ~e arrow 35,
relative to the quill. The gear 26 meshes with a ~ear 38 camed by a fee~ut
40 through which the L~,e..l~c~. is ~lI.e~c~
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Rotation of the gear 20 drives t~e gears 22 and 26. The gear 22 in turndrives ~e gear 28 and, with it, the quill 30 and Ihe r~ . 10, ~xfhile the
ge~r 26 in turn drives ~e ~gear 38 and, v~ith it, the feeduut 40. If the
fee~cl~r lO and the feednul 40 have a right hand ~re~d, the gear ratios are
seleet~l for a cloc~. ;..~ drive, such th~t the feednut rotates slo~1ver ~an ther~e~-.~ to effect forward movement of the feedscle~r, as inrlir~tf'A by the
"""~pl 35 In the more c~.. ~.. ~ngen.f~lt, the f~le~ and feednut
have a left ha~ ~ead. ~n ~is case ~e gear ratios are sele~d su~ , for
a clockwise drive, ~e feednut rotates faster t~an the fc~ J to calLse the
n~ ~ for~vard movement of the fcc~ he forward and
r~ lglu!-~iol~ 1 m~ tof~Ihef~ J10is Ir~ dtothe
drill rod 14 which acco~ y rotates and moves fon~rardly at the s-ame
line~ aDd an~ular ~peed as the fee~.., thereby to drill a hole 42 into a
rock fonnation 44.
In a typic~l case, the fe~.,~ . lO is 1,5m long to enable a hole of
co.lc~ o~ np de~th to be d~illed. The leng~ ofthc r~d~ . can however
be probl~ 1 if the drill is situated in a mine worlcing, such as a b~nel
or p~g~, vvhich has a liInited width of 1,5m. I-f, for ;~.s~m. ~ ~e width of
the mine . .Jll~illg is 1,5m it is not ~ I lc to drill, because it is ~ ~.ce~
for the Ç~d~lc~! to move folvvardly durin~ d~illing. Also, it is not pncsible
to add a filrther drill rod at ~e rear of the d~ill rod 14 because the r~d~~
a~ready occul. ~c the filll width of the . Jl~;-)g, One solutinn to the problernwould be to malce the feedscrew 10 shorter, Lhereby allowing a further drill
rod to be added. This reduces ~e available feed len~ and r~ ,S fi~
re~ ;n~, which is ~ener~lly j",~ l Thus it ~nll be app~eciated ~at
~e COll~ inn~l rock drill as dec~bed above and as i~ tc~l in Figures
I and 2 is llnc~ P for use ~II ~r~ine wolk~g~ of rectr~-tpA width
SUMMARY OF T~E; INVENT~ON 2 1 9 9 5 7 9
According to tbe present invention t~ere is pro~nded a rotary rock d~ill
corr~rricin~ a rot~t~bl~, axially imm~ili~A l~d~ .., a feednut lhLv.lgh
which the Ic~~ is ~d, drive and gearing means ope ~ to rotate
the h~ v relative to the feednut so ~ the feednut advances linearly on
the leadscfew, linear dri~re traDsfer nleans o~ in use to transfer ~he
linear ad~ ce of the feednut to a drill rod parallel to and spaced apart from
the leadscre~, and rotary drive transfer means o~,.~ se to ~ansfer
ro~ion of ~e lea~ w to the drill rod during li~ear ~d~.a~ of ~e drill
rod.
In the l"o~ d ~ml~o~lim~nt the linear dr~ve ~ sfer means c~S~r~ise~ a
nllhP~ to which are connf~t,,d bo~ the feednut and a spindle to w}~h lhe
drill rod ca~ be .~h.l.~
In ~is emhorlim~nt~ the ro~y drive tra~sfer means Gomrri~ a quill whichis rot~ ly fast wi~ tlle lea~ew aDd a gear tr~in, inrl~ gears fast
u~ith the quill and w~dl dle spin~lle ~I.ecLvely, for ~ f~ ~; .L rota~ion fiom
~e leadscrew ~ the s~indle, alld hence to a drill rod cl. ~ -d in use to ~e
spindle.
The drive and geanng means may ~ e a motor driving ~e~ e ge~r
tr~ins which operate to rotate the leadscrew and feednut at difterent speeds
so that there is relative rotation be~een ~e l~d~ c~ andthe feednutwhic~
causes ~e feednut to advance on the l~
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B~E~ DESCR~PTION OF THE ~)~AWINGS
The ~nvention will now be ~Iç~ihe~ ~n more detail, wi~ le~ lce to the
~cc~ z..j~ a~ in which:
Fi~ure 1 s~ows a ~ t;t; p~tiy S~tiOnp~ side view of
a conventional rock drill;
Figqre 2 shows a cross-section at the lille 2-2 ~n Figure l; and
Figure 3 shows a diagr~atic, pa~ly secti~n~d side view of
a rock drill hccu~ to ~e preserlt inventio~
DESCRIPTION O~ A ~RE~RRl; n EM~ODIhqENT
As described above, Figures 1 and 2 i t~ a conr~"lt;Gnal rock drill
wbich s~ers ~rom the dis~l~,~tage that it is ~ for use in rnine
~rkirle~ of .c~ ~ ;eh~ width
This ~ of the c~ Lional rock drill is addressed by the rock drill
u~)GS3~l by ~e present invention and a ~JlL~Ll,lL~1 e ~ of which is
illu~l~l in Figure 3. In this e ~ho~ e-~, the f~~ 0 of Fig~e I is
replaced by a s~lid 1 '- ~ l00 which is n1O~ L1 for rotation in ~ ;s
102 carried by ~ dle 104 An air motor l06, conv.,.ficl~ of ~e same
type as is used in conventionsl drills, is ....~ to the cradle and drives a
~!ear 108 which meslles with a ~ear 110 ~ast on the l~d~ 100.
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21 99579
Thus the ledds~e.r 100 rotates at a speed ~i~.~ nA' ~f on the OU~I~t speed of
the motor and the rati~ of the gears 108 and 110. Tlle le~.~ passes
through a quill 112 ~hich, lilce the quill 30 io Fi~,~e 1, has inwardly
directed splines or keys wich e~ e in ~oo~es or k~ 114 in dle
lea~lsc~w. Thus rotation of the l~ds~c~.r causes C~ G~1~On~ rotalion of
the qu~ll.
The quill carr~es a gear 115 ~xhich ~neshes wi~ a gear 116 on a sha~ 118
which also ca~ies a gear 120. Ihe gear 120 meshes with a gear 122 carried
by a feednut 124 through which the l~dsr-l... is l}l~G~.de~. The gear 116
meshes ~th a gear 126 OIl a spindle 128 throug~ which a drill rod 130
passes The drill rod 130 is ~~hllr~l to the spin~lle by a chuck 132.
Ihe spindle 128 is con~ d to a ~nllh~ 134 which is also cQn~ ~,t~d to
the feednut 124. The ra~o of ~e gear tra~n cO~ , of the gears 11~, 116,
120 and 122 is c;llosen so that ~ere ~s rdative rota~ion ~~ the kadsL.~,,
100 and the ~eedIlut 124 q1hich causes ~e fe~ut to screw forwardly on the
leads~ ,... The foru~ard mo~t of the feednut 124 is 1.,....rr rl~ to the
drillhead 134, spindle 128 and drill rod 130, as indicated by the arrow 136.
ThlLs the drill rod is dri~en rul .. . dl~ at the same linear speed as the feedn~lt
and is rotated at a speed /~let - ~ by the oueput speed of ~e air motor 106
and ~e rel~ive ratios of ~e gear ~inS rnnCichr~ of the gears 108, 110 an~
115, 116 and 126.
~- f~mn~ to tbe prior ~rt confi~ ;on of Figures 1 and ~, re-~k~l~L i~-
~of the dri~l can be effect by discoDnecting the drive ~o the feednut 40. The
feedllut ~s ~en held s~a~inn9ry by means of a lever ~ ~L ~,e~ with a hole in
the f~
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The motor 18 is driven ~n a ~li~inn O~Y~J~ to tbat used for llrilli~, ie.
~nti~lo~ L w~se. This re~ ts the feedscrew. The re~raction take~ place at hi~h
speed because the feednut 40 is st~tiQn~y and there is acco,.li~
a~ relative l~.o~ e~l ~ch. ~ n the feednut and the r~,&d3ele.~. Prior
to ~ .n of the fc~ lO, the chuck 12 is lo.,~ retraction
a new drill rod is fitted and the chuck 1~ is re~ l,tn ~
Ln the embo~l;"~ of ~ e 3, a similar yl~)c~lure can be carried out during
h~rL ;n~, In this case, The drive to the feednut 124 is ~liscor ~ , the
feednut is held sta~onary and ~e motor 106 is lc~ d to retract ~e
~lnllh~ 1;4 at a rapid rale
It will be appreciated ~at this method of re-chllr~in~ ~quin,s a bi-
dire~tirnsl motor 18, 106. The lleccsa;ly for a bidirectional motor 18, 10~
can be avoided in cases where ~e feednut 40, 124 and feedscrew 10 or
l~ds~ . 100 ha~re a left hand ~ead. Dun~g drilling, the geaI ratios arG
sele~ed such ~at, for a clockwise dri~e, the feedn~ 40, 124 rotates faster
thanthefce~L.c. 10/leads~c~ 100, therebyto ~ t~forward lo~e~e,l~
of the fceds."c~ 10 or drillhe~d 134. When re-rk.~L i..p is to talce place, the
feednut 40, 124 is lleld St~tif~n~ry so lhat the clocA-.;~ drive applied to the
f~d~;lc~ 10/leadsc~ew 100 ca~ses ~e r~ or tlnll~ to retract
rapidly.
The eonfig~ ;Qn illuall~t~l in ~i~ure 3 has an i~llpo~ ,~Lge when
COnl~ Gd to thc con~- .I;o,.~l CQnf~ dlion of Figure 1. The spindle 128 can
much short~r than the Ç~scre~- 10, because the feed length is not
dct .n;~.~d by the sp~ndle, but by the feed leng~ of the l~d~l~. 100.
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The length of the spindle 128 together with the chuck 132 may, for inct~nrP
be as little as 0,5m as olJposed to ~e typical 1,5m f~l~ u,l'c~d in
the conventional an~em~nt. This ~ turn means ~lat, in a n~ine worl~ing
having a r~i.,ted width of, say, 1,5m, anod er drill rod of 1,0m length can
be added behind the drill rod 130. The feed len~h which is ;~ttqir-al- in
each instance is dct~ ..i~d by the distance that the feednut can adlrance on
the leadscrew 100. However the length ofthe leadscrew may be only sLightly
less than ~e width of the mine ~orking, because it does not move ~cially
as in the cu~ ional system, thereby allow~ng a ~lhs~nti~l feed lengdl to
be ob~ .A
