Title of Invention	A DRILLING APPARATUS HAVING IN-LINE EXTENDING WINGS AND DRIVING METHOD THEREOF
Abstract	The present invention relates to a borehole drilling apparatus with in-line extending wings and driving method thereof. The drilling apparatus comprises a guide device rotating while moving upwardly and downwardly in a casing to fit into aborehole, extending wings for exter?ling the diameter of adriUedhole, ar?iapUotbitinstelledatalowerportionofthe guide deviceto strike the bottom of the borehole, wherein spiral projections formed at a lower surface of tiie guide device slidably engage with guide grooves formed at a side of the extending wings to each other, and a window is formed at a side of Hie pilot bit for advancing and retracting the extending wings so that they can spread and return linearly from the center of the pilot bit

Title of Invention

A DRILLING APPARATUS HAVING IN-LINE EXTENDING WINGS AND DRIVING METHOD THEREOF

Abstract

The present invention relates to a borehole drilling apparatus with in-line extending wings and driving method thereof. The drilling apparatus comprises a guide device rotating while moving upwardly and downwardly in a casing to fit into aborehole, extending wings for exter?ling the diameter of adriUedhole, ar?iapUotbitinstelledatalowerportionofthe guide deviceto strike the bottom of the borehole, wherein spiral projections formed at a lower surface of tiie guide device slidably engage with guide grooves formed at a side of the extending wings to each other, and a window is formed at a side of Hie pilot bit for advancing and retracting the extending wings so that they can spread and return linearly from the center of the pilot bit

Full Text	ADRttUNG APPARATUS HAVING IN-LINE EXTENDING WINGS AND DRIVING METHOD THEREOF Technical Field The present invention relates to a borehole drilling apparatus having in-line extending wings and driving method thereof, in particular to a borehole dtilh^ apparatus rmvirig in-line extending wings, which comprises a guide device operated by high pressure air, extending wings and a pilot bit, fee extending wings being configuted to advance and retract in an in-line manner so as to extend fee diameter of a borehole so feat sludge can be prevented from being accumulated in fee space to which fee extending wings return, and a driving method thereof. Background Art In general, hammer bit equipment used in drilling a rxnsk)kinduo a rotation apparatus, a striking apparatus and a drilling apparatus. The present invention is directed to fee drilling apparatus located at fee lowest portion of fee hammer bit equipments. The drilling apparatus can be divided into an eccentric type, an extending type and a blade extending type dependmg cm mearis for extending fee diameter of fee borehole, for instance, fee structure of a reamer, extending blades or arms. As disclosed in US Patent No. 4,770,259 (Published on Sep. 13,1988), fee eccentric type drilringapparatairidiiateadriUstri^ string. Further, the cutting device consists of an r^frmp^a^. portion rotating within the ffri)] string and an outer surface. Also, a reamer is installed in fee intermediate portion so that it is offeet wife regard to fee center axis. Accordingly, fee reamer extends fee diameter of fee rwrebole by ecceaitric rotation in fee eccentric type drilling apparatus. In addition, as shown in Japanese Patent Laid-Open Publication No. 2710192(published on Nov. 29, 1994), fee extending type drilling apparatus comprises a device driven by means of an air pomp, a bit device installed at a distal end of the device, and an extending blade installed between the device and 1he bit device. The extending blade is secured at an upper end to the device by means of a pin so that it can move angularly in the vertical direction, and the upper end portion of the bit device is formed to have an inclined surface. Therefore, the lower end portion of the extending blade is configured to diverge along the inclined surface of the bit device when me device and the bit device come close to each other Further, as shown in U.S. Patent No. 5,787,999(issued on Aug. 4,1998), the blade extending type drilling apparatus includes a driver, under-reameraons, and a pilot bit, in which a plurality of arms are constructed to project and retract while rotating from me center of the pilot bit to the inclined direction by means of arotation force of the driver. However, with regard to the eccentric type drilling apparatus, it is impossible to carry out rapid drfllmg work as the reamer rotates eccen intermediate portion is liable to be damaged easily under high load. Also, with regard to the extending type drilling apparatus, it is impossible to use it under high load as the extending blade is extended with fa angular movement tn thp IcmgfriiHinal direction, and the fixing pin is apt to be damaged easily. Further, in contrast to the eccentric or extending type drilling apparatus, although the blade extending type drilling apparatus can be used for high load drilling apparatus, there is a problem in that the contact portion between the arms and fee pilot bit is susceptible to serious abrasion because the rotation force of the driver should spread the arms forcibly and rotate even the pilot bit via the arms at tie same time, and the securing pin for fixing the arms are damaged fiequently. Additionally, when-the arms return to their original positions after the completion of the drilling work, sludge is liable to be jammed in the space where 1he arms return to thereby hinder fteanns'relum to merr original positions, so that it becomes somewhat difficult to retract the drilling apparatus from the casing to fit into the borehole. Disclosure of Invention Technical Problem Hie present invention has been made to solve the above-mentioned problems occurring in the conventional striking type borehole drilling apparatus, and it is an object of the present invention to provide a borehole drilling apparatus of an improved structure,, in which it is possible to perform a drilling work under a high load and at a high speed, it is easy to spread and return the eximiiiig wings, the working efficiency is excellent as the sludge is not accumulated in the space where the extending wings return, and it is possible to significantly reduce the maintenance and repair costs. Technical Solution To accomplish the above object, according to one aspect of the present invention, there is provided a borehole drilling apparatus and driving method thereof, wherein the borehole drilling apparatus comprises a guide device rotating wife moving up and down in a casing to fit into the borehole, extending wings for extending the diameters of the drilled holes, and a pilot bit installed at a lower portion of tie guide device to strike the bottom ofthe borehole, wherein spiral projections formed at a lower surface of Ihe guide device slidably engage with guide grooves formed at sides of the extending wings to each other, and a window is formed at a side of fee pilot bit for advancing and retracting foe extending wings so that they can spread ard return hneariynxim the caiter of the jotbk In the present invention, as described above, the term of "In-line" driving manner refers to a manner in which the extending wings spread from each other linearly from the center of the pilot bit, andtneyretumto come close to each other linearly. Brief Description of Drawings Further objects and advantages of the present invention can be more fidly understood from the following detailed description taken in conjunction with the accompanying drawings in which: FIG 1 is a cross-sectional view showing structure of a borehole drilling anparate according to the present invention, HG2isaviewshowingstnictaBofaguidedevicKlC)OshowninFlG 1, FIG 3 is a structural view showing extending wings 200 shown inFIG 1, FIG 4A is a planar view showing the extending wings 200, and FIG 4B is a cross-sectional view of the extending wings taken along the line S-S, FIG 5 is a structural view showing apilot bit 300 shown in Fig. 1, FIG 6A is a planar view of the pilot bit 300, FIG 6B is a cross-sectional view of the pilot bit taken along the line S-S, FIG 6C is a cross-sectional view ofthe pilot bit taken along the line S'-S', FIG 7 is a view showing structure of a ring-type pin according to an embodiment of the present invention, FIGs. 8 and 9 are views showing installing structure of the securing pin 400 according to another embodiment of the present invention, FIGs. lOandll are \dews ejcplainingrn in-line driving method of the present invention. Best Mode for Carrying Out the Invention The present invention will hereinafler be described in iurther detail with reference to fhe preferred embodiments. FIG lisacross-secticraalviwshovflngstnjcft^ the present invention, FIG 2 is a view showing structure of aguide device 100 shown in FIG 1, FIG 3 is a structural view showing extending wings 200 shown in FIG 1, FIG 4A is a planar view showing the extending wings 200, and FIG 4B is a cross-sectional view of the extending wings taken along the line S-S.FIG 5 is a perspective view showing a pilot bit 300 shown in Fig. 1, and FIG 6A is a planar view of the pilot hat 300, FIG 6B is a cross-sectional view oftiie pilot bit taken along the line S - S, FIG 6C is a cross-sectional view of the pilot bit taken along the line S'- S'. As shown in FIG 1, the borehole dolling apparatus comprises a guide device 100 engaged with a striking device (not shown), extending wings 200 uistaUed at a lower portion of the guide device 100 to extend the diameter of 1he borehole, andapilot bit 300 for dulling the ground while supporting the extending wings 200. In an embodiment of the present inventiori, a ring-type pin 400 is OMistnict^ as pin engaging Tnejms fhr engaging fra guide device 100 with the pilot bit 300. At first, as shown in FIG 2, the guide device 100 includes an upper shaft portion 120, alower shaft portion 130 which have a smaller diameter, and a piston portion 110 having a relatively larger diameter Iban the ur^ard lower shaft portions. As showninFIG 1, the piston portion 110 is installed within a casing 10 while maintaining a small gap theje^jetweensothatitopeiatestostrikBanTqjperend of the a shoe 12 installed at a lower end of the casing 10 to thereby progress the casing 10 into the rxjrehde. A plurality of sludge disdiar^^ of the piston portion 110 for discharging the sludge such as scrils, pebbles, and foe like product dining the drilling process from the borehole. As showninFIG 1, an air hole 20 is formed alorig a center axis of the piston portion 110 while passing through the piston portion 110, the upper shaft portion 120, and 1he lower shaft portion 130 for supplying high pressure air along Has longitudinal direction tram the outside. The upper shaft portion 120 is provided with shaft engaging grooves 121 formed on the outer circumferential surface thereof for engaging with the striking device (not shown), which is an upper structure of the drilling apparatus. Spiral projections 131 with curved surface are formed at Ihe bottom of the lower shaft portion 130, in which the diameter of 1he curved surface increases progressively from the center, and a retaining protrusion 132 is formed on the outer circumference of the lower shaft portion 130. Also, a pin groove 133 is fbmied with whicfo the ring-type pin 400 is engaged, along the outer circumfetential surface at just belowthe piston portion 110, that is, an upper side of the lower shaft portion 130, The extending wings 200 are configured as shown in FIGs. 3 and 4, a guide groove 210 is formed at the inside of the extending wings for engaging with the spiral projection 131 of the guide device 100. Also, a stepped surface 220 is formed on the oursi&irpper surface of the extending wing 200, and an inclined surface 230 is framed at a lower comer of the extending wings. Firthet; a piurafity of button tips 40 made of special steel are driven into the inclined surface 230 to facilitate the drilling work. Meanwhile, as shown in FIGs. 5 and 6, the pilot bit 300 is configured to be a cylindrical vessel shape, and fee lower shaft portion 130 of the guide device 100 and the extending wings 200 are received in the pilot hit 300. A KxSangular-shaped window 310 for advancing and retracting the extending wing 200 is farmed at a side of the pilot bit 300, a retaining step 320 is formed inwardly fiom an inner ottumfbential surface of the pilot bit to correspood to the retaining protruacm 132 100, and a pin groove 330 is formed at a position oftie inner dramfeenrial surface correspond pin groove 133 of the lower shaft portion ISO.TbepingrcwveSSOisramrrranicatrvelj'comffictedw the outside by a pin insertion hole 331. Also, an air hole 20 is formed at a lower surface of the pilot bit 300, and a pluralit}' of sludge discharge grooves 30 are formed on.the outer ckamoferendal surface of the pilot bit, and button tips 40 are driven into 1he lower surface of the pilot bit FIG 7 shows structure of aring-1ype pin 400 used in an embodiment of the present invention, in which a plurality of arc-shaped pins are combined to fcm a circle. The ring-type pm^ is ft into a pin groove 133 formed at the outer drcMmfoential surface of the bwer shaft portion 130 of fee guide device 100, and a pin hole is formed by tie pin groove 330 defined at the inner dnamferential surface of the pilot bit 300 to damp the guide device 100 and the pilot bit 300. In this instance, each of the arcshaped pte 410 are inserted into 1hepm We respec^^ formed at 1he pin groove 330 of Ihe pilot bit 300. Apin support element 332 is inserted into the pin insertion hole 331 so that Ihe arc-shaped pins 410 cannot be separated from the pin holes, and a bolt (not shown) is engaged with a bolthole 333 feerebyton^iishlhedarrqingoflheririg-lypepia Meanwhile, FIG 8 arri FIG 9 show different embcximente^ the pin engagement means for clamping Ihe guide device 100 and Ihe pilot bit 300 includes a securing pin 450 and a pin support rod 460 instead of Ihe ring-type pin 400. FIG 8 shows longitudinal crosssection of the extending wing 200 and the pilot bit 300, and FIG 9 shows cross-section taken along the line S-S of FIG 8. As shown in the drawings, apin insertion hole 350 is formed obliquely at a side of the pilot bit 300, and a pin retaining groove 360 is formed on the inner circumferential surface of the pilot bit Also, a run insertion hole 135 extending irom the pin insertion hole 350 is formed obliquely at the upper end of the lower shaft portion 130 ofthe guide device 100, and a pk receiving groove 136 is formed within the pin insertion hole 135 to correspond to the pk retaining groove 360. In order to assemble 1he borehole drilling apparatus according to Hie embodiment of the present invention, the securing pin 450 is inserted into fte pin rectiving groove 136 of the guide device 100 at first, 1he guide device 100 is inserted into and engaged with the pilot bit 300, and then the pin support rod 460 is forcibly pushed into the insertion hole 135 via 'the pin insertion hole 350. In this instance, the pin support rod 460 pushes out the seoirirjg pin 450 so that it can be engaged wim the pin retaining groove 360 of the pilot bit 300 to thereby damp the guide device 100 and the pilot bit 300 to each other. The in-line driving method of tie borehole drilling apparatus of Ihe present invention wfll now be described below. FIG 10 and FIG 11 are views for explaining the driving principle of the drilling; apparatus in which two extending wings 200 are arranged linearly side by side according to an embodiment of Hie present invention. At first, as shown in FIG 10, the guide device 100 (represented by 1hick solid line) rotates clockwise to descend with the pilot bit 300 in a state where the extending wings 200 (represented by dotted thick line) are received wiftlin the pilot bit 300 (represented by 1bin solid line). When the lower surface of the pilot bit 300 begins to strike a bottom surface of the borehole, rotation of the pilot bit 300 will be suppressed by the fiictional force, and ifthe guide device 100 arfnues to rotate atfe state, the spiral projections 131 (represented by a dotted portion) rotates along the guide groove 210 (represented by reverse inclined lines) of the extending wing 200 in the direction enlarging radius to spread and extend the extending wings 200 to the outside ofthe wing advancing and redactirigwiridcnvSlO. In this instance, the extending wing 200 is spread and extended lineariy away frcm the center of tepUot bit 300 via the advancing and retracting window 310. Then, as shown inHG 11, when the retaining protrusion 132 of the glide device 100 contacts the retaining step 320 (shown by inclined lines), spreadmg of the extendbg wdrj^ 200 is stop rotation force of tie guide device 100 is transmitted to the pttot bit 300 itself to rotate Ihe guide device 100, the extending wing 200 and Ihe pilot bit 300 integrally to cany out the drilling work Sludge such as pebbles, sands and so on produced during the drilling work can be discharged \ia fee sludge discharge hole 30 by means of fee compressed air supplied from the air hole 20. Meanwhile, Ihe return process of the extending wing 200 for 1he borehole begins with reverse rotation and ascending of 1he guide device 100. In olher words, as shown in HG 11, when the guide device 100 rotates counter-clockwise to ascend in a state where 1be extending wings 200 are spread, 1he stepped surface 220 of the extending wings 200 contacts with the lower end of a shoe 12 in the casing 10, and the rotation of the extending wing 200 tor the borehole is suppressed by the fiictional force. At this state, if the guide device continues to rotate reversely, the spiral projections 131 (represented by a dotted portion) move along the guide groove 210 of Ihe extending wing 200 in Has direction decreasing the radius to thereby return the extending wings 200 into the window 310 of the pilot bit 300. In this instance, the extending wings 200 return linearly to come close each other to the center of the pilot bit 300 via the advancing and retracting window 310 for the wings. When the guide device 100 rotates reversely to contact with the retaining step 320 (shown by inclined solid lines), as shown in FIG ll.the extending wings 200 finish returning, atulfee guide device 100, the extending wings 200 and the pilot bit 300 rancurranflyrotatetoretactfirantiie casing 10. In the present invention, although it is preferable that two extending wings 200 are installed at both side as described in the above embodiment, three extending wngs may be installed, if desired In case of installing three extending wings 200, tie driving principle is basically the same as that of installing two extending wings. However, the spiral projections 131 of the guide device 100 and the wing advancing and retracting window 310 of tie pilot bit 300 should be installed to be three so feat they can cope with three extending wings 200. While tie present invention has been described wife reference to fee pnrferred embodiments, the present invention is not restricted by the embodiments. It is to be appreciated th& art can change or modify tie embodiments without departing fiom 1he scope and spirit of the present invention. However, such variations and TnnrlificatinTis are all pertained to the scope of tie present invention. Industrial Applicability As described above, according to the borehole drilling appai^is of trie present invention, it is possible to cany out high load and high speed drilling work because tbs extending wings advance and retract in an in-line manner, and in particular, the sludge is not aoamulated at the position where fee extending wings advance and retract Also,itispo&sible to signifitantyreduceaworkiiigpmodiequiiedto finish fee drilling of fee borehole, considering that the conventional drilling apparatus has frequently stop operation and has been susceptible to disorder due to accumulation of the sludge. In particular, when the sludge is accumulated between the extending wings to thereby block smooth returning of 1fae extending wings, 1he whole drilling apparatus cannot be retracted fiom the borehole and it should be discarded, therefore, according to teraesentirivention, it is possible to esq)ect a reduction of the costs caused by the lost of the equipments. What Is Claimed Is: 1. A borehole drilling apparatus with in-line extending wings, comprising a guide device, wings for extending a borehole, and a pilot bit, wherein fee guide device is configured to be a cylindrical stnicttnB through wMchm air hole is passed along a center axis thereof, and includes an upper shaft portion, a piston portion and a lower shaft portion, wherein the piston portion is farmed on the outer dramrferential surface Ihereof with a plurality of sludge discharging grooves; and the lower shaft portion is formed at 1he lower surface thereof with spiral projections, the spiral projections each having a curved surface whose radius increases from the center, and formed at a side thereof with a retaining protrusion and pin engaging means; wherein the extending wing is wholly configured to be a rectangular structore, and is formed at a side thereof with a guide groove for engaging slidably wife the cmved surface of the srjrral projection belowthe guide device; and wherein the pilot bit is configuredto have aconcave structure in which, the lower shaft portion of the guide device and the extending wings are received, the pilot bit being formed at a side "thereof with an advancing and retracting window for the extending wing, formed at the inner circumferential surface thereof with a retaining step and pin engagement means for restricting the rotation of the guide device by the retaining protrusion, formed atthe lower surface thereof with an air hole, and formed at the outer circumferential surface thereof with a plurality of sludge discharging grooves. 2. The drilling apparatus of claim 1, wherein the pin engagement means comprise pin grooves, each of which is formed at positions corresponding to each other along the outer circumferential surface of the lower shaft portion in the guide device and the inner circumferential surface of the pilot bit, and a ring-type pin consisting of a plurality of arc-shaped pins inserted into the pin grooves. 3. The drilling apparatus of claim 1, wherein the pin engagement means comprise insertion holes formed obliquely at side of the pilot bit, pin retaining grooves formed at the inner circumferential surface of tie pilot bit, insertion holes formed at the upper end of the lower shaft portion in -toe guide device to extend from the insertion holes of the pilot bh, pin receiving grooves formed at the inside of the insertion holes to correspond to the pin retaining grooves, securing pins engaged with the pin receiving grooves of the guide device and the pin retaining grooves of the pilot bit, and pin support rods inserted into the insertion holes. 4. The drilling apparatus of claim 1, wherein the extending wings installed are two or three in number. 5. A driving method of a borehole drilling apparatus comprising: a guide device, wings for extending a borehole and a pilot bit, the driving method comprises the steps of. suppressing the rotation of the pilot bit by the fiictional force produced when the extending wings rotate and descend integrally with the guide device in a state where the extending wings are received in the pilot bit, and then a bottom surface of the pilot bit begins to strike a botom surface of the borehole; spreading the extending wings outwardly from a wing advancing and retracting window formed at a side of the pilot bit by the movement of the spiral projections formed at a lower surface of the guide device along guide grooves formed at a side of the extending wings in the direction increasing radii of the spiral projections by the roiatioa force of the guide device, when the guide device continues to rotate in a state where the rotation of the pilot bit is suppressed; drillingthe borehole with the integral rotation of tine guide device, the extending wings and the plot bit, after the stop of the spread of the extending wings whoa an retaining trolruaonfomjed on the outer cncuraference of fee guide device is caught by aretaining step formed atthe inner rarcumferential surface of the pilot bit; suppressing the rotation of the extending wings by the fiicaonal force produced when upper surfaces of the extending wings comes into contact wife a shoe of the rasing to fit into the borehole, after the guide device rotates reversely and ascends atthe state of spread of the extend^ wings; returning the extending wings into 1he wing advaricing and exfflacti^ by the movement of the spiral projections of 1he guide device along the guide grooves of "the extending wings in the direction decreasing radii of 1he spiral projections by the roianonibrce ofthe guide device, when the guide device continues to rotate reversely in a state where fceioladancf tine extemSngwirigE are suppressed; and retracting the guide device, the extending wings and the pilot bit fiom the casing while integrally rotating them after the stopping of tie return ofthe extending wings, when the retaining protmsian farmed an the outer circumference of the guide device contacts with the retaining step ibrmed atthe inner circumferential surface ofthe pilot bit.

Full Text

ADRttUNG APPARATUS HAVING IN-LINE EXTENDING WINGS AND DRIVING
METHOD THEREOF
Technical Field
The present invention relates to a borehole drilling apparatus having in-line extending wings
and driving method thereof, in particular to a borehole dtilh^ apparatus rmvirig in-line extending wings,
which comprises a guide device operated by high pressure air, extending wings and a pilot bit, fee
extending wings being configuted to advance and retract in an in-line manner so as to extend fee
diameter of a borehole so feat sludge can be prevented from being accumulated in fee space to which
fee extending wings return, and a driving method thereof.
Background Art
In general, hammer bit equipment used in drilling a rxnsk)kinduo a rotation apparatus, a
striking apparatus and a drilling apparatus. The present invention is directed to fee drilling apparatus
located at fee lowest portion of fee hammer bit equipments. The drilling apparatus can be divided into
an eccentric type, an extending type and a blade extending type dependmg cm mearis for extending fee
diameter of fee borehole, for instance, fee structure of a reamer, extending blades or arms.
As disclosed in US Patent No. 4,770,259 (Published on Sep. 13,1988), fee eccentric type
drilringapparatairidiiateadriUstri^
string. Further, the cutting device consists of an r^frmp^a^. portion rotating within the ffri)] string and
an outer surface. Also, a reamer is installed in fee intermediate portion so that it is offeet wife regard to
fee center axis. Accordingly, fee reamer extends fee diameter of fee rwrebole by ecceaitric rotation in fee
eccentric type drilling apparatus.
In addition, as shown in Japanese Patent Laid-Open Publication No. 2710192(published on
Nov. 29, 1994), fee extending type drilling apparatus comprises a device driven by means of an air
pomp, a bit device installed at a distal end of the device, and an extending blade installed between the
device and 1he bit device. The extending blade is secured at an upper end to the device by means of a
pin so that it can move angularly in the vertical direction, and the upper end portion of the bit device is
formed to have an inclined surface. Therefore, the lower end portion of the extending blade is
configured to diverge along the inclined surface of the bit device when me device and the bit device
come close to each other
Further, as shown in U.S. Patent No. 5,787,999(issued on Aug. 4,1998), the blade extending
type drilling apparatus includes a driver, under-reameraons, and a pilot bit, in which a plurality of arms
are constructed to project and retract while rotating from me center of the pilot bit to the inclined
direction by means of arotation force of the driver.
However, with regard to the eccentric type drilling apparatus, it is impossible to carry out rapid
drfllmg work as the reamer rotates eccen
intermediate portion is liable to be damaged easily under high load. Also, with regard to the extending
type drilling apparatus, it is impossible to use it under high load as the extending blade is extended with
fa angular movement tn thp IcmgfriiHinal direction, and the fixing pin is apt to be damaged easily.
Further, in contrast to the eccentric or extending type drilling apparatus, although the blade
extending type drilling apparatus can be used for high load drilling apparatus, there is a problem in that
the contact portion between the arms and fee pilot bit is susceptible to serious abrasion because the
rotation force of the driver should spread the arms forcibly and rotate even the pilot bit via the arms at
tie same time, and the securing pin for fixing the arms are damaged fiequently. Additionally, when-the
arms return to their original positions after the completion of the drilling work, sludge is liable to be
jammed in the space where 1he arms return to thereby hinder fteanns'relum to merr original positions,
so that it becomes somewhat difficult to retract the drilling apparatus from the casing to fit into the
borehole.
Disclosure of Invention
Technical Problem
Hie present invention has been made to solve the above-mentioned problems occurring in the
conventional striking type borehole drilling apparatus, and it is an object of the present invention to
provide a borehole drilling apparatus of an improved structure,, in which it is possible to perform a
drilling work under a high load and at a high speed, it is easy to spread and return the eximiiiig wings,
the working efficiency is excellent as the sludge is not accumulated in the space where the extending
wings return, and it is possible to significantly reduce the maintenance and repair costs.
Technical Solution
To accomplish the above object, according to one aspect of the present invention, there is
provided a borehole drilling apparatus and driving method thereof, wherein the borehole drilling
apparatus comprises a guide device rotating wife moving up and down in a casing to fit into the
borehole, extending wings for extending the diameters of the drilled holes, and a pilot bit installed at a
lower portion of tie guide device to strike the bottom ofthe borehole, wherein spiral projections formed
at a lower surface of Ihe guide device slidably engage with guide grooves formed at sides of the
extending wings to each other, and a window is formed at a side of fee pilot bit for advancing and
retracting foe extending wings so that they can spread ard return hneariynxim the caiter of the jotbk
In the present invention, as described above, the term of "In-line" driving manner refers to a
manner in which the extending wings spread from each other linearly from the center of the pilot bit,
andtneyretumto come close to each other linearly.
Brief Description of Drawings
Further objects and advantages of the present invention can be more fidly understood from the
following detailed description taken in conjunction with the accompanying drawings in which:
FIG 1 is a cross-sectional view showing structure of a borehole drilling anparate according to
the present invention,
HG2isaviewshowingstnictaBofaguidedevicKlC)OshowninFlG 1,
FIG 3 is a structural view showing extending wings 200 shown inFIG 1,
FIG 4A is a planar view showing the extending wings 200, and FIG 4B is a cross-sectional
view of the extending wings taken along the line S-S,
FIG 5 is a structural view showing apilot bit 300 shown in Fig. 1,
FIG 6A is a planar view of the pilot bit 300, FIG 6B is a cross-sectional view of the pilot bit
taken along the line S-S, FIG 6C is a cross-sectional view ofthe pilot bit taken along the line S'-S',
FIG 7 is a view showing structure of a ring-type pin according to an embodiment of the
present invention,
FIGs. 8 and 9 are views showing installing structure of the securing pin 400 according to
another embodiment of the present invention,
FIGs. lOandll are \dews ejcplainingrn in-line driving method of the present invention.
Best Mode for Carrying Out the Invention
The present invention will hereinafler be described in iurther detail with reference to fhe
preferred embodiments.
FIG lisacross-secticraalviwshovflngstnjcft^
the present invention, FIG 2 is a view showing structure of aguide device 100 shown in FIG 1, FIG 3
is a structural view showing extending wings 200 shown in FIG 1, FIG 4A is a planar view showing
the extending wings 200, and FIG 4B is a cross-sectional view of the extending wings taken along the
line S-S.FIG 5 is a perspective view showing a pilot bit 300 shown in Fig. 1, and FIG 6A is a planar
view of the pilot hat 300, FIG 6B is a cross-sectional view oftiie pilot bit taken along the line S - S, FIG
6C is a cross-sectional view of the pilot bit taken along the line S'- S'.
As shown in FIG 1, the borehole dolling apparatus comprises a guide device 100 engaged
with a striking device (not shown), extending wings 200 uistaUed at a lower portion of the guide device
100 to extend the diameter of 1he borehole, andapilot bit 300 for dulling the ground while supporting
the extending wings 200. In an embodiment of the present inventiori, a ring-type pin 400 is OMistnict^
as pin engaging Tnejms fhr engaging fra guide device 100 with the pilot bit 300.
At first, as shown in FIG 2, the guide device 100 includes an upper shaft portion 120, alower
shaft portion 130 which have a smaller diameter, and a piston portion 110 having a relatively larger
diameter Iban the ur^ard lower shaft portions. As showninFIG 1, the piston portion 110 is installed
within a casing 10 while maintaining a small gap theje^jetweensothatitopeiatestostrikBanTqjperend
of the a shoe 12 installed at a lower end of the casing 10 to thereby progress the casing 10 into the
rxjrehde. A plurality of sludge disdiar^^
of the piston portion 110 for discharging the sludge such as scrils, pebbles, and foe like product dining
the drilling process from the borehole. As showninFIG 1, an air hole 20 is formed alorig a center axis
of the piston portion 110 while passing through the piston portion 110, the upper shaft portion 120, and
1he lower shaft portion 130 for supplying high pressure air along Has longitudinal direction tram the
outside.
The upper shaft portion 120 is provided with shaft engaging grooves 121 formed on the outer
circumferential surface thereof for engaging with the striking device (not shown), which is an upper
structure of the drilling apparatus. Spiral projections 131 with curved surface are formed at Ihe bottom
of the lower shaft portion 130, in which the diameter of 1he curved surface increases progressively from
the center, and a retaining protrusion 132 is formed on the outer circumference of the lower shaft
portion 130. Also, a pin groove 133 is fbmied with whicfo the ring-type pin 400 is engaged, along the
outer circumfetential surface at just belowthe piston portion 110, that is, an upper side of the lower shaft
portion 130,
The extending wings 200 are configured as shown in FIGs. 3 and 4, a guide groove 210 is
formed at the inside of the extending wings for engaging with the spiral projection 131 of the guide
device 100. Also, a stepped surface 220 is formed on the oursi&irpper surface of the extending wing
200, and an inclined surface 230 is framed at a lower comer of the extending wings. Firthet; a piurafity
of button tips 40 made of special steel are driven into the inclined surface 230 to facilitate the drilling
work.
Meanwhile, as shown in FIGs. 5 and 6, the pilot bit 300 is configured to be a cylindrical vessel
shape, and fee lower shaft portion 130 of the guide device 100 and the extending wings 200 are
received in the pilot hit 300.
A KxSangular-shaped window 310 for advancing and retracting the extending wing 200 is
farmed at a side of the pilot bit 300, a retaining step 320 is formed inwardly fiom an inner
ottumfbential surface of the pilot bit to correspood to the retaining protruacm 132
100, and a pin groove 330 is formed at a position oftie inner dramfeenrial surface correspond
pin groove 133 of the lower shaft portion ISO.TbepingrcwveSSOisramrrranicatrvelj'comffictedw
the outside by a pin insertion hole 331. Also, an air hole 20 is formed at a lower surface of the pilot bit
300, and a pluralit}' of sludge discharge grooves 30 are formed on.the outer ckamoferendal surface of
the pilot bit, and button tips 40 are driven into 1he lower surface of the pilot bit
FIG 7 shows structure of aring-1ype pin 400 used in an embodiment of the present invention,
in which a plurality of arc-shaped pins are combined to fcm a circle. The ring-type pm^ is ft into a
pin groove 133 formed at the outer drcMmfoential surface of the bwer shaft portion 130 of fee guide
device 100, and a pin hole is formed by tie pin groove 330 defined at the inner dnamferential surface
of the pilot bit 300 to damp the guide device 100 and the pilot bit 300. In this instance, each of the arcshaped
pte 410 are inserted into 1hepm We respec^^ formed at 1he
pin groove 330 of Ihe pilot bit 300. Apin support element 332 is inserted into the pin insertion hole 331
so that Ihe arc-shaped pins 410 cannot be separated from the pin holes, and a bolt (not shown) is
engaged with a bolthole 333 feerebyton^iishlhedarrqingoflheririg-lypepia
Meanwhile, FIG 8 arri FIG 9 show different embcximente^
the pin engagement means for clamping Ihe guide device 100 and Ihe pilot bit 300 includes a securing
pin 450 and a pin support rod 460 instead of Ihe ring-type pin 400. FIG 8 shows longitudinal crosssection
of the extending wing 200 and the pilot bit 300, and FIG 9 shows cross-section taken along the
line S-S of FIG 8. As shown in the drawings, apin insertion hole 350 is formed obliquely at a side of
the pilot bit 300, and a pin retaining groove 360 is formed on the inner circumferential surface of the
pilot bit Also, a run insertion hole 135 extending irom the pin insertion hole 350 is formed obliquely at
the upper end of the lower shaft portion 130 ofthe guide device 100, and a pk receiving groove 136 is
formed within the pin insertion hole 135 to correspond to the pk retaining groove 360.
In order to assemble 1he borehole drilling apparatus according to Hie embodiment of the
present invention, the securing pin 450 is inserted into fte pin rectiving groove 136 of the guide device
100 at first, 1he guide device 100 is inserted into and engaged with the pilot bit 300, and then the pin
support rod 460 is forcibly pushed into the insertion hole 135 via 'the pin insertion hole 350. In this
instance, the pin support rod 460 pushes out the seoirirjg pin 450 so that it can be engaged wim the pin
retaining groove 360 of the pilot bit 300 to thereby damp the guide device 100 and the pilot bit 300 to
each other.
The in-line driving method of tie borehole drilling apparatus of Ihe present invention wfll now
be described below. FIG 10 and FIG 11 are views for explaining the driving principle of the drilling;
apparatus in which two extending wings 200 are arranged linearly side by side according to an
embodiment of Hie present invention.
At first, as shown in FIG 10, the guide device 100 (represented by 1hick solid line) rotates
clockwise to descend with the pilot bit 300 in a state where the extending wings 200 (represented by
dotted thick line) are received wiftlin the pilot bit 300 (represented by 1bin solid line). When the lower
surface of the pilot bit 300 begins to strike a bottom surface of the borehole, rotation of the pilot bit 300
will be suppressed by the fiictional force, and ifthe guide device 100 arfnues to rotate atfe state, the
spiral projections 131 (represented by a dotted portion) rotates along the guide groove 210 (represented
by reverse inclined lines) of the extending wing 200 in the direction enlarging radius to spread and
extend the extending wings 200 to the outside ofthe wing advancing and redactirigwiridcnvSlO. In this
instance, the extending wing 200 is spread and extended lineariy away frcm the center of tepUot bit
300 via the advancing and retracting window 310.
Then, as shown inHG 11, when the retaining protrusion 132 of the glide device 100 contacts
the retaining step 320 (shown by inclined lines), spreadmg of the extendbg wdrj^ 200 is stop
rotation force of tie guide device 100 is transmitted to the pttot bit 300 itself to rotate Ihe guide device
100, the extending wing 200 and Ihe pilot bit 300 integrally to cany out the drilling work Sludge such
as pebbles, sands and so on produced during the drilling work can be discharged \ia fee sludge
discharge hole 30 by means of fee compressed air supplied from the air hole 20.
Meanwhile, Ihe return process of the extending wing 200 for 1he borehole begins with reverse
rotation and ascending of 1he guide device 100. In olher words, as shown in HG 11, when the guide
device 100 rotates counter-clockwise to ascend in a state where 1be extending wings 200 are spread, 1he
stepped surface 220 of the extending wings 200 contacts with the lower end of a shoe 12 in the casing
10, and the rotation of the extending wing 200 tor the borehole is suppressed by the fiictional force. At
this state, if the guide device continues to rotate reversely, the spiral projections 131 (represented by a
dotted portion) move along the guide groove 210 of Ihe extending wing 200 in Has direction decreasing
the radius to thereby return the extending wings 200 into the window 310 of the pilot bit 300. In this
instance, the extending wings 200 return linearly to come close each other to the center of the pilot bit
300 via the advancing and retracting window 310 for the wings.
When the guide device 100 rotates reversely to contact with the retaining step 320 (shown by
inclined solid lines), as shown in FIG ll.the extending wings 200 finish returning, atulfee guide device
100, the extending wings 200 and the pilot bit 300 rancurranflyrotatetoretactfirantiie casing 10.
In the present invention, although it is preferable that two extending wings 200 are installed at
both side as described in the above embodiment, three extending wngs may be installed, if desired In
case of installing three extending wings 200, tie driving principle is basically the same as that of
installing two extending wings. However, the spiral projections 131 of the guide device 100 and the
wing advancing and retracting window 310 of tie pilot bit 300 should be installed to be three so feat
they can cope with three extending wings 200.
While tie present invention has been described wife reference to fee pnrferred embodiments,
the present invention is not restricted by the embodiments. It is to be appreciated th&
art can change or modify tie embodiments without departing fiom 1he scope and spirit of the present
invention. However, such variations and TnnrlificatinTis are all pertained to the scope of tie present
invention.
Industrial Applicability
As described above, according to the borehole drilling appai^is of trie present invention, it is
possible to cany out high load and high speed drilling work because tbs extending wings advance and
retract in an in-line manner, and in particular, the sludge is not aoamulated at the position where fee
extending wings advance and retract
Also,itispo&sible to signifitantyreduceaworkiiigpmodiequiiedto finish fee drilling of fee
borehole, considering that the conventional drilling apparatus has frequently stop operation and has
been susceptible to disorder due to accumulation of the sludge.
In particular, when the sludge is accumulated between the extending wings to thereby block
smooth returning of 1fae extending wings, 1he whole drilling apparatus cannot be retracted fiom the
borehole and it should be discarded, therefore, according to teraesentirivention, it is possible to esq)ect
a reduction of the costs caused by the lost of the equipments.

What Is Claimed Is:
1. A borehole drilling apparatus with in-line extending wings, comprising a guide device,
wings for extending a borehole, and a pilot bit,
wherein fee guide device is configured to be a cylindrical stnicttnB through wMchm air hole is
passed along a center axis thereof, and includes an upper shaft portion, a piston portion and a lower
shaft portion,
wherein the piston portion is farmed on the outer dramrferential surface Ihereof with a
plurality of sludge discharging grooves; and the lower shaft portion is formed at 1he lower surface
thereof with spiral projections, the spiral projections each having a curved surface whose radius
increases from the center, and formed at a side thereof with a retaining protrusion and pin engaging
means;
wherein the extending wing is wholly configured to be a rectangular structore, and is formed at
a side thereof with a guide groove for engaging slidably wife the cmved surface of the srjrral projection
belowthe guide device; and
wherein the pilot bit is configuredto have aconcave structure in which, the lower shaft portion
of the guide device and the extending wings are received, the pilot bit being formed at a side "thereof
with an advancing and retracting window for the extending wing, formed at the inner circumferential
surface thereof with a retaining step and pin engagement means for restricting the rotation of the guide
device by the retaining protrusion, formed atthe lower surface thereof with an air hole, and formed at
the outer circumferential surface thereof with a plurality of sludge discharging grooves.
2. The drilling apparatus of claim 1, wherein the pin engagement means comprise pin
grooves, each of which is formed at positions corresponding to each other along the outer
circumferential surface of the lower shaft portion in the guide device and the inner circumferential
surface of the pilot bit, and a ring-type pin consisting of a plurality of arc-shaped pins inserted into the
pin grooves.
3. The drilling apparatus of claim 1, wherein the pin engagement means comprise insertion
holes formed obliquely at side of the pilot bit, pin retaining grooves formed at the inner circumferential
surface of tie pilot bit, insertion holes formed at the upper end of the lower shaft portion in -toe guide
device to extend from the insertion holes of the pilot bh, pin receiving grooves formed at the inside of
the insertion holes to correspond to the pin retaining grooves, securing pins engaged with the pin
receiving grooves of the guide device and the pin retaining grooves of the pilot bit, and pin support rods
inserted into the insertion holes.
4. The drilling apparatus of claim 1, wherein the extending wings installed are two or three in
number.
5. A driving method of a borehole drilling apparatus comprising: a guide device, wings for
extending a borehole and a pilot bit, the driving method comprises the steps of.
suppressing the rotation of the pilot bit by the fiictional force produced when the extending
wings rotate and descend integrally with the guide device in a state where the extending wings are
received in the pilot bit, and then a bottom surface of the pilot bit begins to strike a botom surface of the
borehole;
spreading the extending wings outwardly from a wing advancing and retracting window
formed at a side of the pilot bit by the movement of the spiral projections formed at a lower surface of
the guide device along guide grooves formed at a side of the extending wings in the direction increasing
radii of the spiral projections by the roiatioa force of the guide device, when the guide device continues
to rotate in a state where the rotation of the pilot bit is suppressed;
drillingthe borehole with the integral rotation of tine guide device, the extending wings and the
plot bit, after the stop of the spread of the extending wings whoa an retaining trolruaonfomjed on the
outer cncuraference of fee guide device is caught by aretaining step formed atthe inner rarcumferential
surface of the pilot bit;
suppressing the rotation of the extending wings by the fiicaonal force produced when upper
surfaces of the extending wings comes into contact wife a shoe of the rasing to fit into the borehole,
after the guide device rotates reversely and ascends atthe state of spread of the extend^ wings;
returning the extending wings into 1he wing advaricing and exfflacti^
by the movement of the spiral projections of 1he guide device along the guide grooves of "the extending
wings in the direction decreasing radii of 1he spiral projections by the roianonibrce ofthe guide device,
when the guide device continues to rotate reversely in a state where fceioladancf tine extemSngwirigE
are suppressed; and
retracting the guide device, the extending wings and the pilot bit fiom the casing while
integrally rotating them after the stopping of tie return ofthe extending wings, when the retaining
protmsian farmed an the outer circumference of the guide device contacts with the retaining step
ibrmed atthe inner circumferential surface ofthe pilot bit.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=x1D4ybs71dr35xZvLLhSIA==&loc=+mN2fYxnTC4l0fUd8W4CAA==

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Patent Number

278122

Indian Patent Application Number

2023/DELNP/2007

PG Journal Number

52/2016

Publication Date

16-Dec-2016

Grant Date

14-Dec-2016

Date of Filing

15-Mar-2007

Name of Patentee

EVERDIGM ROCK TOOLS CORP.

Applicant Address

300 WANJUSANDAN-5RO, BONGDONG-EUP, WANJU-GUN, JEOL LABUK-DO, REPUBLIC OF KOREA, 565-904,

Inventors:

#	Inventor's Name	Inventor's Address
1	LIM, BYUNG-DUK	SEOHO APT. 105-1104, SONGCHEONDONG 1-GA, DEOKJIN-GU, JEONJU-SI, JEOLLABUK-DO, 561-301 REPUBLIC OF KOREA

PCT International Classification Number

E21B 1/30

PCT International Application Number

PCT/KR2005/002918

PCT International Filing date

2005-09-02

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10-2004-0070565	2004-09-03	Republic of Korea