Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to seals for a wet drilling
arrangement, par~icularly for drilling in ear~h ~ormations, as
in connection wi~h mining operations.
; Drilllng in earth ~ormations is widely practiced durlng
mining and much of ~he drilling takes place underground. Drilling
often consists of ~he drilling o~ fairly small holes in a forma-
tion ~or various reasons, and when this work is done underground,
; a great deal of fines and dust can be developed which crea~es
~`; hazardous and unhealthy conditions.
^~ 10 It is desirable in such cases to carry out drilling opera-
` tj tions with a supply of a water-air mixture so as to reduce or
~ eliminate the hazardous conditions referred to above.
; The use of the water-air mixture for suppression of dust or
;, fines, while necessary, sometimes can create unwanted collections
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i of water on the mine floor or uncomfortably damp conditions for
ï the operators of such drilling equipmentO
In order to limit the amount of water used, drilling systems
are usually provided with an arrangement where air may be mixed
` ~ with the water so that the operator may mix the water and air to
20 a desired consistency which may be necessary to suppress the dust
~ and fines of the particular material being drilledO
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Most of the drilling systems that mix ~he air a~d water have
no positive seal arrangement for confining the water and air
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throughout the leng~h of the drill string. Usually, the close
metal-to-metal fit between the drill sections and thelr respective
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~;~ con~ectors is considered adequate to lnsure that at least a part
o~ the air and water mixture injected at the beginning of the
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drill string will arrive at the working end of the drill s~ring
thereby ~lushing and suppressing the fines and dust created by
the drilling operation.
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~ Such systems~ because o~ either no posi~ive or adequate
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~ sealing of the drill string sections, therefore, use excessive
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amounts of water than what may be necessary to suppress said dust
and fines. Further, such drilling systems make it difficult for
the operator to have positive control over the mixture of air and
;~ water ~hat reaches ~he worki~g end of the bit. While the operator
may be able to control precisely the mixture at ~he beginning of
the drill string, he does not have any positive control over the
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mixture that arrives at the working end of the drill string where
control of the mixture is important.
~; It is an object of the present invention to provide a sealing
system for wet drilling apparatus so that excessive amounts of
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;~ water are not used to suppress the dust and ines,
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~ It is a further object of the present invention to provide
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the operator of the drilling apparatus greater control over the
mixture of air and water that arrives at the working end o the
drill string.
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; It is a further object of the present invention to reduce
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the ~mount of water which may collect on the mine floor during
such drilling operations.
BRIEF SUMMA~Y OF THE INV~NTION
~ Accord~ng to the present invention, elastomeric seals are
s ~ provided between the individual tubular drill string sections and
the tubular connec~ors interconnecting said drill strings in an
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end to end rel~tion. Near -the end of each i~dividual drill
string, an annular shoulder is provided on the inside periphery
of the tubular drill string with the shoulder facing outwardly
toward one end of a tubular connector.
A ring-like elastomeric seal is then seated on said
annular shoulder and a tubular connector is telescopically
engaged with the tubular drill string section. The tubular
connector has one end which is adapted to be inserted inside one
end of the tubular drill string section and is of sufficient
length to engage and compress the ring-like elastomeric seal
against the annular shoulder.
. The tubular connector has an abutment shoulder provided
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-~' on it so that the end of the tubular drill string section will
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abut the shoulder on the tubular connector, khe portion of the
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tubular connector inside the drill string being a sufficient
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~,~ length to compress the elastomeric ring-like seal. The one end
~ of the tubular connector which telescopically engages the
;~ tubular drill string is provided with an undercut recess and a
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~1 resilient expansion ring is put in said recess to provide a
i ~ 20 frictional connection to keep the tubular connector engaged with
' ~1 at least one of the individual drill string sections.
~,, In accordance with one broad aspect, the invention
relates to a tubular drill string for wet drilling which
comprises: separate tubular drill string sections; a tubular
sl
~ connector telescopically engaging and nonrotatively joining at
,-~ least two of said tubular drill string sections in coaxial end
~1 to end relation, at least one end of one said section having an
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~"~``/J axially outwardly facin~ shoulder formed and spaced from
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the ad]acent end of the respective section, a reslllent annular
1 30 seal member in said one end of said section seated on said
shoulder and engaging the end of said tubular connector which is
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inserted into the respective end of said drill string section to
form a seal between the respective section and said connector,
and friction means holding said connector and said sections
together.
The exact nature of the present invention will become
more clearly apparen~ upon reference to the ~ollowing detailed
specification taken in connection with the accompanying drawings
in which:
Figure 1 is a partially broken away assembly plan view
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of a wet drilling apparatus.
Figure 2 is a sectional view of a connection between the
~- drill string and a tubular connector.
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Figure 3 is a sectional view showing a tubular connector
int~rconnecting two indlvidual drill string sectionsO
DET~ILED DESCRIPTION OF THE INVENTION
Referring to the drawings somewhat more in detail, shown in
Figure 1 is a rotary drive motor and coupling 10 which connec~s
to a base section 12 of the drill string to be ro~ated. Base
' ~ section 12 is a par~ of an entire drill string which is made up of
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; individual drill string sections such as 14 and 16, all of wh~ch
are interconnected in an end to end relationship, using as many
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~` 10 individual drill string sections as may be necessary.
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5~"'' The working end of the entire drill string usually has a
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~ tool chuck 18 which is the tool performing the actual work in
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drilling the hole in the mine. Such a wet drilling apparatus is
usually supplied with a mixture of air and water which is intro-
~, duced into the hollow sections 20 which extends throughout the
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~ entire drill string and communicates with port 22~ with port 22
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delivering the mixture of air and water to ~he working end o~ thedrill string.
The drilling apparatus has individual supplies of air and
water supplied by conduits 24 and 26 which communicate to an
annular space 28 formed around drill string section 12O Surround-
ing the communica~ion paths of both the air and water is usually -
a seal member 30 to prevent any leakage between the air and water
supplies and the base section of drill string 12~ The air and
water are both supplied to the annular cavi~y 28 and the annular
cavîty 28 conm~micates to a radial communication passage 32 which
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~,~ delivers the air and water mixture ~o the hollow central cavity 20
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with drill string sect~on 12. Shown interconnecting individual
drill string sections 14 and 16 is a tubular drill string connec~or
34 which is shown abuttingly engaging one end of both drill s~ring
section 14 and 160
Shown in Figure 2 is a partially broken away section of the
detailed connection between one end of tu~ular connector 34 and
drill section 14~ A ~ubular connec~or 34 has a shoulder 36 which
abu~s end 38 of tubular sec~ion 140 Onè end 38 of the tubular ~ :
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:~ connector 34 is polygonal and, preferably, hexagonal around its
periphery and telescopically engages the one end 38 of drill
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: l~ section 14.
The one end 38 of drill section 14 has been formed by welding
~r ' a ~ubular section of material onto an end of drill section 14.
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The end section 38 has the same dimensions o~ its outside
~! periphery as ~hat of the drill section 14 but the inside periphery
.~ of the end 38 is larger than the inside periphery of the drill
string 14 so that a shoulder 40 is formed and faces outwardly
toward the tubular connector 34.
Seated on the annular shoulder 40 is an elastomeric ring-like
seal 42 which is adapted to seat on one side against the annular
ring 40 and on the other side is adapted to engage or abut the
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extreme end of section 38 of tubular connec~or 34~ A recess 44
iS provided on the periphery of section 38 so that a resilient
., expansible ring 46 may be seated therein to provide a frictional
engagement between the tubular connector 34 and the o~e end 38 of
~he drill string section 14.
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: ~ When ~he tubular connector 34 is telescopically engaged
i;: with drill string section 14, the one end 38 wlll abut shoulder
~ - 36 of the ~libular eonnector 34 and section 38 of tubul~r connector
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~:~ 34 will abut or compress the ring-like elastomeric seal 42
~: against the annular shoulder 40 of drill string section 14.
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:~1 Shown in Figure 3 is a detailed sectionalized view showing a
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~ tu~ular ~on~ector 34 interconnec~ing betwe~n the drill string ~
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. section 14 and the drill string section 16. The ring-like ~
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` ~ elastomeric seal 42 is shown engaging sections 38 of the tubular
:-j lO drill string connector 34.
, ,s However, tubular connector 34 is shown having a recess 44 on
one end onlyO The frictional connection may be necessary on one
end only such that when the drill string sections 14 and 16 are
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disconnected, the tubular connector 34 will be held cap~ive by at ~
least one of said drill s~ring sec~ions. :;
-~ Modiflcations may be made within the scope of the appended -
~ claims. : -
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