|Publication number||US2776819 A|
|Publication date||8 Jan 1957|
|Filing date||9 Oct 1953|
|Priority date||9 Oct 1953|
|Publication number||US 2776819 A, US 2776819A, US-A-2776819, US2776819 A, US2776819A|
|Inventors||Brown Philip B|
|Original Assignee||Brown Philip B|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (130), Classifications (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
n- 1 P. B. BROWN 2,776,819
ROCK DRILL BIT Filed 00$. 9, 1953 2 Shets-Sheet 1 v Fig. 2. 9
INVENT OR PHILIP B. BROWN 4d BY ATTORNEY P. B. BROWN Jan. 8, 1957 Filed 195s RocK DRILL BIT Philip B. Brown, Hidalgo de Parral, Mexico Application October 9, 1953, Serial No. 385,209
2 Claims. (Cl. 255-63) This invention relates to improvements in percussion type of rotary rock drilling bits.
The primary object of this invention is the provision of an improved rock drilling bit which has a rapid and economical drilling action; improved features being provided by means of which, without resharpening, the bit will drill holes in rock deeper and with greater rapidity than with conventional rock drill bits.
In my 'U. S. Patents 2,358,052 and 2,725,216, I have shown rock drill bits provided with means to facilitate initial penetration of rock, the shattering of it, and reaming thereof. In the present bit, I have provided means "to drill a bore of uniform diameter, having rock drilling and shattering lugs and laterally projecting wings. As
the lugs and wings become worn'the bore of the opening will naturally tend to' become smaller. I have provided other auxiliary'wings, the upper portions of which project above the first mentioned wings. After the lugs and first mentioned'wings have become worn the upper portions of the auxiliary lugs take over and ream out a rind of the work or material 'being bored and thus: maintain a bore of uniform diameter.
designate corresponding parts throughoutthe several views:
' Fig/l .is-a side elevation of the improved rock drill bit, showing application thereto of improved features in connection withcross head chisel type lugs. i
Fig. 2 is a bottom'plan view of the improved drilling bitof Fig. 1.
Figs. 3 and 4 are cross sectional views taken through the improved drilling bit, substantially on the respective -'li'njes S Y-Sand '4-4 shown-in Figs. 1 and 2 of the drawings.
1 Fig. 5 isa perspective view of the improved drilling bit of Fig. 1, showing the'manner in which the rock penetrating chisel lugs and associated parts will wear, and also showing wearupon the improved auxiliary shoulder means used therewith.
Fig.6 is a side elevation of a modified form of improved drilling bit having also associated as a part thereof, auxiliary reaming shoulders only brought into :actionafter some initial bore penetration.
Fig. 7 is a bottom plan view of the bit of Fig. 6.
Figs. 8 and 9 are cross sectional views taken substantiallyon their respective lines 8-8 and 99 shown in Figs. 7 and 6" of the drawings.
Fig. 10 is a perspective view of the bit of Fig. 6, showing wearaction on the parts of the drill bit as an incident of user United States Patent '0 lengths.
Patented Jan. 8, 1957 Fig. 11 is a vertical cross sectional view taken through one of the conical shaped pilot drilling lugs or teeth of the bit of Fig. 6, the view being enlarged and taken-sub stantially on the line 1111 shown in Fig. 7 of the drawings.
Referring to the drill bit A as shown in Figs. 1 to 5 inclusive, the same includes 'a cylindrical body portion 15 having a screw threaded socket 16 inwardly from the top surface 17 thereof for detachably receiving a drilling rod. The body portion 15 is provided with a bottom surface 18 and has an axial water passage 20 therethrough opening on the'bottom surface 18. In a drilling bit of this type it is conventional to' provide tapered rock shattering faces 21 surrounding the passageway 20. This bit A is also provided'with conventional cross head chisel lugs 24 having faces 22'-located at an angle of with respect to each other. These chisel lugs are spaced from and located beyond the central area of faces 21 and extend radially into and are integral with Wings 25. The latter are four in number and each extends axially along the body portion and radially beyond the outer circumference 26-of the body portion 15 a predetermined distance to a top edge 25'. The intersection of the sides 31 of the wings 25 with the outer surface of each of said wings provide sharp rock abraiding corners '30. The outer surfaces of the wings 25 may be fiat or arcuate as shown in the drawings. Such outer surfaces are concentric to the outer surface of the body portion and which surfaces are struck from the same radius dimension throughout their lengths.
Because of increased wear upon the outer circumference of the bit,.particularly upon the wings 25, such type of bit can only effectively drill a predetermined shallow depth because of reverse taper which forms on these wings. It isthen necessary to replace the rock bit or to sharpen it. As an improved feature of the bit A, I have provided rock removing, reaming and shattering wings 40 between the Wings 25 at aradial angleof 45 with respect to the adjacent wings 25. These Wings 40'have outer faces 41 (Fig. 2) which are struck from the same radius or lie in the same radius as the outer surfaces of the wings 25, and are concentric at their outer surfaces to the body-portion 15 and which surfaces are struck from the same radius dimension throughout their They are axially arranged along the body portion 15 with the upper ends thereof extending appreciably above the top edges 25' of the wings25. The intersection of the side surfaces 43 of said auxiliary wings 40with the outer surface 41 form reaming edges 42.
The bottom surface of the wings 40 may lie in the same plane as the bottom surface 18 of the body portion 15.
In starting a new rock bore, the drill rod is rotated, and since this is a percussion type drill bit many hundreds of impact blows per minute are applied to the bit. The shattering action commences with lugs 24 and subsequently the wings 25 also chip and penetrate the bore of the rock leaving a cylindrical bore or hole which is slightly larger in diameter than the extreme surface-- diameter of the lugs 24 and'outer surfacing of the wings 25. The auxiliary wings 40 will therefore not bind in the hole. Due to use the diameters of holes being bored tend to decrease as the'outer edges of the lugs 24 and the wings 25 wear. With conventional rock bits the wearing of the bit slows the action of pentrationand narrows the diameter of'the bore to'such'an extent that a following rock bit has to be used which is a fraction of an inch less in effective diameter. With the improved rock bit of this'invention as the lower part'of the bore narrows, due to wear upon the lugs 24, the wings-25am the lower portions of the auxiliary wings '40, the upper portions of the latter above the edges 25 take over, wear:
ing away a thin rock rind. Thereby the rock bit of this invention has a longer life than conventional rock bits and can be used for drilling a uniform diametered bore of greater depth than can be obtained with conventional rock bits because of the relation of the wings 25 and 40.
As shown at 55 in Fig. 5, the auxiliary wings 40 wear as an incident of reaming action at the outer circumference just above the bottom of the bore. It is an important feature of the invention that the auxiliary wings are so arranged as to enable quick and easy resharpening of the bit. This is accomplished by squaring up the wings 25 and 40 of the bit. This is initially done and then the central part of the bit head can be ground out surrounding the water passageway 20.
The length of the auxiliary wings stabilizes the position of the bit head to the sides of the drill hole.
When the bit head A is resharpened 1 have found that in connection with a 2 inch diametered bit it is necessary to decrease the effective bore drilling diameter of the bit by A of an inch, to provide sharp corners for the wings 25 and 40.
Referring to the form of invention B shown in Figs. 6 to 11 inclusive, the same includes a body portion 60, preferably cylindrical in formation, having a drill rod receiving screw threaded socket 61 therein. This body portion 60 has the usual water passageway 62 opening on the bottom surface 63.
The bit B presents certain novel characteristics over the form of bit A, in that it is provided with rock penetrating and removal lugs 64, at 90 apart which extend outwardly and are connected to radially extending wings 65. The wings 65 are of the same construction and for the same purpose as the Wings 25 above described. They terminate at top edges 65 and their outer surfaces are concentric with the outer surface of the body 60. These arcuate surfaces are struck from the same radius dimension throughout the lengths of the wings. They project beyond the outer circumferential surface 66 of the body portion 60, as shown in the drawings. The lugs 64 have bottom surfaces 67 at their outer ends all lying in the same plane at right angles to the axis of the drill bit. This plane is located below the plane of the bottom surface 63. The rock drilling lugs 64 each have side surfaces 68 and 69 which convergently slope towards the center of the drill bit, and also are convergently inclined from the bottom surface 63 of the drill bit body portion. This shape of the lugs 64 gives an inner sloping sharp rock pentrating edge 70 and where the sides 68 and 69 intersect with the surface 67 there are also provided sharp edges 71. While these lugs alone can furnish the initial rock drilling action I may also add to them pilot drilling teeth 80, i of conical formation. They project downwardly below the bottom surface 67 of each of these teeth and are located in an annular band between the inner and outer portions of each of the wings 65. The teeth 80 have the shape characteristics of the conical lugs of my U. S. Patent 2,725,216, dated February 5, 1956. At any point of plane intersection through the axis of each lug, the latter is in the form of a Gothic arch. Thus, the lugs are each in the form of Gothic half-spheres. Referring to the geometrical construction of these points or teeth, the base line of the tooth, as indicated at 81 in Fig. 11, lies in the plane of the bottom surface 67 of the rock penetrating lug 64. The convex curvature of the side walls 82 is struck from radii 83, the centers 84 of which are located in the Outer circumference of the base line 81; the apex 85 being determined by intersection of the surfaces struck from the radii 83. The diameter of the base 81 is less than the height 86 of the tooth 80. This type of rock penetrating tooth has been found by me to possess the necessary mass and strength for rugged rock penetrating work, the advantages of which are more fully set forth in my above identified copending application.
As a feature of the rock bit B, in common with the rock bit A, I provide auxiliary wings 90, 45 between adjacent lugs 64. Four of these are provided on the conventional 2 inch drilling bit, and they are of the same construction, and have the same characteristics as the auxiliary wing constructions 40 of the form of invention A, in that they extend lengthwise along the body portion 60 to a greater extent than the effective rock abrading and removing wings 65, as will be noted from Fig. 6 of the drawings. Furthermore, at the intersection of their outer surfaces with the side edges thereof, the wings 90 are provided with sharp corners 93. The upper portions pro ject appreciably above the top edges 65 of the wings 65 and their outer surfaces are concentric with the outer surface of the body 60. Their arcuate surfaces are struck from the same radius dimension throughout the lengths of the wings.
The use of the bit B is similar to the bit A in that the bottom surfaces of the wings 90 are located in the plane of the bottom surface 63 of the body portion of the bit and which plane is appreciably spaced from the drilling planes of the teeth and the lugs 64. It is only when the teeth 80, lugs 64, wings 65, and the lower portions of wings have been sufficiently worn that the upper portions of the auxiliary wings 90 take over and continue reaming of a shallow rind for the purpose of continuing a uniformly diametered bore. In Figure 10 is shown wear upon lugs 64 and wear 96 upon the auxiliary wings. The conical lugs have the same self-sharpening feature as pointed out in my Patent 2,725,216.
Resharpening of the bit B can be easily accomplished.
From the foregoing it can be seen that an improved drilling bit construction, of the percussion type, has been provided; the auxiliary wing and shoulder constructions of which are shaped to economically prolong the life of the bit and enable deeper drilling of bores. These auxiliary wings act with a rock removal and reaming action both on the up and down motion of the bit head and also upon rotation backward and forward.
The wings of these bits project from the side walls of the body portion of the bit to take care of the rim or outer portion to be removed as part of the bore. In comparative tests of the bit A of this application with a conventional cross head bit of the same size and material, the conventional bit after drilling 4 feet of bore was removed. It had appreciable wear upon the same and with the bit of this application a rock bore of 15 feet through the same strata was made with 3 as much wear as on the tested conventional cross head bit.
It is within contemplation of this invention to place pilot teeth on the chisel lugs of the bit A of this application in the same relationship as they are placed upon the tapered lugs of the form of invention B.
Various changes in the shape, size and arrangement of parts may be made to the form of invention herein shown and described without departing from the spirit of the invention or scope of the claims.
1. A percussion type rotary rock drill bit comprising a body portion having a bottom surface, rock penetrating chisel shaped lugs radially arranged upon and connected to said body portion and depending below the bottom surface, said lugs at their outermost ends extending appreciably laterally of the outer side surfacing of the body portion, elongated wings provided on and extending axially of the body portion and forming lateral extensions and extending laterally of said body portion for the same distances as the lateral extensions of the respective lugs, said wings each having an arcuate outer surface which is struck from the same radius dimension along the length thereof, the sides of said wings forming with said arcuate surface sharp rock abrading edges, and elongated auxiliary rock reaming wings connected to and extending axially of said body portion at locations between the first mentioned wings and parallel thereto, the lower ends thereof lying intermediate the tops of the first wings and said lugs, and also laterally extending from the outer side surfacing of the body portion throughout their lengths for the same distance as said first mentioned wings, said auxiliary wings having arcuate outer surfaces which are struck from the same radius dimension throughout the lengths thereof, the sides of which form with said arcuate outer surfaces sharp rock abrading edges, said auxiliary wings being axially longer than the first mentioned wings and extending along said body appreciably above the upper ends of said first mentioned wings.
2. A percussion type rotary rock drill as described in claim 1 in which pilot drilling teeth of inverted substantial conical shape formation are connected to said lugs and depend therefrom at locations on said lugs inwardly of the said wings.
References Cited in the file of this patent UNITED STATES PATENTS
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US893596 *||27 Dec 1905||21 Jul 1908||Robert Hutchison Anderson||Rock-drill.|
|US1034803 *||7 May 1912||6 Aug 1912||Konrad Jonassen||Combination rock drill and reamer.|
|US2592440 *||26 Jun 1946||8 Apr 1952||Thompson Products Ltd||Rock drilling tool|
|US2696973 *||9 Feb 1951||14 Dec 1954||Francis R Britton||Nonsticking drill bit|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3258077 *||30 Dec 1963||28 Jun 1966||Orville Phipps||Piercing point hammer drill bit|
|US4043409 *||22 Mar 1976||23 Aug 1977||Walter Hans Philipp||Drill steel for deep drill hammers|
|US4716976 *||28 Oct 1986||5 Jan 1988||Kennametal Inc.||Rotary percussion drill bit|
|US4911729 *||22 Aug 1989||27 Mar 1990||Rooker Robert E||Overburden eliminator rock drill bit|
|US5836408 *||9 Dec 1996||17 Nov 1998||Hilti Aktiengesellschaft||Rotary percussion blow assisted drill|
|US6868924 *||22 Mar 2001||22 Mar 2005||Hawera Probst Gmbh||Rock drill|
|US7225886||22 Dec 2005||5 Jun 2007||Hall David R||Drill bit assembly with an indenting member|
|US7258179 *||2 Jun 2006||21 Aug 2007||Hall David R||Rotary bit with an indenting member|
|US7392857||3 Jan 2007||1 Jul 2008||Hall David R||Apparatus and method for vibrating a drill bit|
|US7419016||1 Mar 2007||2 Sep 2008||Hall David R||Bi-center drill bit|
|US7419018||1 Nov 2006||2 Sep 2008||Hall David R||Cam assembly in a downhole component|
|US7424922||15 Mar 2007||16 Sep 2008||Hall David R||Rotary valve for a jack hammer|
|US7484576||12 Feb 2007||3 Feb 2009||Hall David R||Jack element in communication with an electric motor and or generator|
|US7497279||29 Jan 2007||3 Mar 2009||Hall David R||Jack element adapted to rotate independent of a drill bit|
|US7527110||13 Oct 2006||5 May 2009||Hall David R||Percussive drill bit|
|US7533737||12 Feb 2007||19 May 2009||Hall David R||Jet arrangement for a downhole drill bit|
|US7559379||10 Aug 2007||14 Jul 2009||Hall David R||Downhole steering|
|US7571780||25 Sep 2006||11 Aug 2009||Hall David R||Jack element for a drill bit|
|US7591327||30 Mar 2007||22 Sep 2009||Hall David R||Drilling at a resonant frequency|
|US7600586||15 Dec 2006||13 Oct 2009||Hall David R||System for steering a drill string|
|US7617886||25 Jan 2008||17 Nov 2009||Hall David R||Fluid-actuated hammer bit|
|US7641002||28 Mar 2008||5 Jan 2010||Hall David R||Drill bit|
|US7661487||31 Mar 2009||16 Feb 2010||Hall David R||Downhole percussive tool with alternating pressure differentials|
|US7694756||12 Oct 2007||13 Apr 2010||Hall David R||Indenting member for a drill bit|
|US7721826||6 Sep 2007||25 May 2010||Schlumberger Technology Corporation||Downhole jack assembly sensor|
|US7762353||28 Feb 2008||27 Jul 2010||Schlumberger Technology Corporation||Downhole valve mechanism|
|US7866416||4 Jun 2007||11 Jan 2011||Schlumberger Technology Corporation||Clutch for a jack element|
|US7886851||12 Oct 2007||15 Feb 2011||Schlumberger Technology Corporation||Drill bit nozzle|
|US7900720||14 Dec 2007||8 Mar 2011||Schlumberger Technology Corporation||Downhole drive shaft connection|
|US7954401||27 Oct 2006||7 Jun 2011||Schlumberger Technology Corporation||Method of assembling a drill bit with a jack element|
|US7967082||28 Feb 2008||28 Jun 2011||Schlumberger Technology Corporation||Downhole mechanism|
|US7967083||9 Nov 2009||28 Jun 2011||Schlumberger Technology Corporation||Sensor for determining a position of a jack element|
|US8011457||26 Feb 2008||6 Sep 2011||Schlumberger Technology Corporation||Downhole hammer assembly|
|US8020471||27 Feb 2009||20 Sep 2011||Schlumberger Technology Corporation||Method for manufacturing a drill bit|
|US8122980||22 Jun 2007||28 Feb 2012||Schlumberger Technology Corporation||Rotary drag bit with pointed cutting elements|
|US8130117||8 Jun 2007||6 Mar 2012||Schlumberger Technology Corporation||Drill bit with an electrically isolated transmitter|
|US8191651||31 Mar 2011||5 Jun 2012||Hall David R||Sensor on a formation engaging member of a drill bit|
|US8201892||10 Dec 2007||19 Jun 2012||Hall David R||Holder assembly|
|US8205688||24 Jun 2009||26 Jun 2012||Hall David R||Lead the bit rotary steerable system|
|US8215420||6 Feb 2009||10 Jul 2012||Schlumberger Technology Corporation||Thermally stable pointed diamond with increased impact resistance|
|US8225883||31 Mar 2009||24 Jul 2012||Schlumberger Technology Corporation||Downhole percussive tool with alternating pressure differentials|
|US8240404||10 Sep 2008||14 Aug 2012||Hall David R||Roof bolt bit|
|US8267196||28 May 2009||18 Sep 2012||Schlumberger Technology Corporation||Flow guide actuation|
|US8281882||29 May 2009||9 Oct 2012||Schlumberger Technology Corporation||Jack element for a drill bit|
|US8292372||21 Dec 2007||23 Oct 2012||Hall David R||Retention for holder shank|
|US8297375||31 Oct 2008||30 Oct 2012||Schlumberger Technology Corporation||Downhole turbine|
|US8297378||23 Nov 2009||30 Oct 2012||Schlumberger Technology Corporation||Turbine driven hammer that oscillates at a constant frequency|
|US8307919||11 Jan 2011||13 Nov 2012||Schlumberger Technology Corporation||Clutch for a jack element|
|US8316964||11 Jun 2007||27 Nov 2012||Schlumberger Technology Corporation||Drill bit transducer device|
|US8322796||16 Apr 2009||4 Dec 2012||Schlumberger Technology Corporation||Seal with contact element for pick shield|
|US8333254||1 Oct 2010||18 Dec 2012||Hall David R||Steering mechanism with a ring disposed about an outer diameter of a drill bit and method for drilling|
|US8342266||15 Mar 2011||1 Jan 2013||Hall David R||Timed steering nozzle on a downhole drill bit|
|US8342611||8 Dec 2010||1 Jan 2013||Schlumberger Technology Corporation||Spring loaded pick|
|US8360174||30 Jan 2009||29 Jan 2013||Schlumberger Technology Corporation||Lead the bit rotary steerable tool|
|US8408336||28 May 2009||2 Apr 2013||Schlumberger Technology Corporation||Flow guide actuation|
|US8418784||11 May 2010||16 Apr 2013||David R. Hall||Central cutting region of a drilling head assembly|
|US8434573||6 Aug 2009||7 May 2013||Schlumberger Technology Corporation||Degradation assembly|
|US8449040||30 Oct 2007||28 May 2013||David R. Hall||Shank for an attack tool|
|US8499857||23 Nov 2009||6 Aug 2013||Schlumberger Technology Corporation||Downhole jack assembly sensor|
|US8522897||11 Sep 2009||3 Sep 2013||Schlumberger Technology Corporation||Lead the bit rotary steerable tool|
|US8528664||28 Jun 2011||10 Sep 2013||Schlumberger Technology Corporation||Downhole mechanism|
|US8540037||30 Apr 2008||24 Sep 2013||Schlumberger Technology Corporation||Layered polycrystalline diamond|
|US8550190||30 Sep 2010||8 Oct 2013||David R. Hall||Inner bit disposed within an outer bit|
|US8567532||16 Nov 2009||29 Oct 2013||Schlumberger Technology Corporation||Cutting element attached to downhole fixed bladed bit at a positive rake angle|
|US8573331||29 Oct 2010||5 Nov 2013||David R. Hall||Roof mining drill bit|
|US8590644||26 Sep 2007||26 Nov 2013||Schlumberger Technology Corporation||Downhole drill bit|
|US8596381||31 Mar 2011||3 Dec 2013||David R. Hall||Sensor on a formation engaging member of a drill bit|
|US8616305||16 Nov 2009||31 Dec 2013||Schlumberger Technology Corporation||Fixed bladed bit that shifts weight between an indenter and cutting elements|
|US8622155||27 Jul 2007||7 Jan 2014||Schlumberger Technology Corporation||Pointed diamond working ends on a shear bit|
|US8701799||29 Apr 2009||22 Apr 2014||Schlumberger Technology Corporation||Drill bit cutter pocket restitution|
|US8714285||16 Nov 2009||6 May 2014||Schlumberger Technology Corporation||Method for drilling with a fixed bladed bit|
|US8820440||30 Nov 2010||2 Sep 2014||David R. Hall||Drill bit steering assembly|
|US8839888||23 Apr 2010||23 Sep 2014||Schlumberger Technology Corporation||Tracking shearing cutters on a fixed bladed drill bit with pointed cutting elements|
|US8931854||6 Sep 2013||13 Jan 2015||Schlumberger Technology Corporation||Layered polycrystalline diamond|
|US8950517||27 Jun 2010||10 Feb 2015||Schlumberger Technology Corporation||Drill bit with a retained jack element|
|US9051795||25 Nov 2013||9 Jun 2015||Schlumberger Technology Corporation||Downhole drill bit|
|US9068410||26 Jun 2009||30 Jun 2015||Schlumberger Technology Corporation||Dense diamond body|
|US9284787||24 May 2013||15 Mar 2016||Black & Decker Inc.||Drill bit and cutting head for drill bit|
|US9316061||11 Aug 2011||19 Apr 2016||David R. Hall||High impact resistant degradation element|
|US9366089||28 Oct 2013||14 Jun 2016||Schlumberger Technology Corporation||Cutting element attached to downhole fixed bladed bit at a positive rake angle|
|US9677343||22 Sep 2014||13 Jun 2017||Schlumberger Technology Corporation||Tracking shearing cutters on a fixed bladed drill bit with pointed cutting elements|
|US9708856||20 May 2015||18 Jul 2017||Smith International, Inc.||Downhole drill bit|
|US20030138304 *||22 Mar 2001||24 Jul 2003||August Haussmann||Rock drill|
|US20070114067 *||22 Dec 2005||24 May 2007||Hall David R||Drill Bit Assembly with an Indenting Member|
|US20070114071 *||2 Jun 2006||24 May 2007||Hall David R||Rotary Bit with an Indenting Member|
|US20070119630 *||29 Jan 2007||31 May 2007||Hall David R||Jack Element Adapted to Rotate Independent of a Drill Bit|
|US20070125580 *||12 Feb 2007||7 Jun 2007||Hall David R||Jet Arrangement for a Downhole Drill Bit|
|US20070221408 *||30 Mar 2007||27 Sep 2007||Hall David R||Drilling at a Resonant Frequency|
|US20070221412 *||15 Mar 2007||27 Sep 2007||Hall David R||Rotary Valve for a Jack Hammer|
|US20070229232 *||11 Jun 2007||4 Oct 2007||Hall David R||Drill Bit Transducer Device|
|US20070229304 *||8 Jun 2007||4 Oct 2007||Hall David R||Drill Bit with an Electrically Isolated Transmitter|
|US20070272443 *||10 Aug 2007||29 Nov 2007||Hall David R||Downhole Steering|
|US20080035380 *||27 Jul 2007||14 Feb 2008||Hall David R||Pointed Diamond Working Ends on a Shear Bit|
|US20080035388 *||12 Oct 2007||14 Feb 2008||Hall David R||Drill Bit Nozzle|
|US20080048484 *||30 Oct 2007||28 Feb 2008||Hall David R||Shank for an Attack Tool|
|US20080099243 *||27 Oct 2006||1 May 2008||Hall David R||Method of Assembling a Drill Bit with a Jack Element|
|US20080142263 *||28 Feb 2008||19 Jun 2008||Hall David R||Downhole Valve Mechanism|
|US20080156536 *||3 Jan 2007||3 Jul 2008||Hall David R||Apparatus and Method for Vibrating a Drill Bit|
|US20080156541 *||26 Feb 2008||3 Jul 2008||Hall David R||Downhole Hammer Assembly|
|US20080173482 *||28 Mar 2008||24 Jul 2008||Hall David R||Drill Bit|
|US20080296015 *||4 Jun 2007||4 Dec 2008||Hall David R||Clutch for a Jack Element|
|US20080302572 *||23 Jul 2008||11 Dec 2008||Hall David R||Drill Bit Porting System|
|US20080314647 *||22 Jun 2007||25 Dec 2008||Hall David R||Rotary Drag Bit with Pointed Cutting Elements|
|US20090000828 *||10 Sep 2008||1 Jan 2009||Hall David R||Roof Bolt Bit|
|US20090057016 *||31 Oct 2008||5 Mar 2009||Hall David R||Downhole Turbine|
|US20090065251 *||6 Sep 2007||12 Mar 2009||Hall David R||Downhole Jack Assembly Sensor|
|US20090133936 *||30 Jan 2009||28 May 2009||Hall David R||Lead the Bit Rotary Steerable Tool|
|US20090133938 *||6 Feb 2009||28 May 2009||Hall David R||Thermally Stable Pointed Diamond with Increased Impact Resistance|
|US20090158897 *||27 Feb 2009||25 Jun 2009||Hall David R||Jack Element with a Stop-off|
|US20090160238 *||21 Dec 2007||25 Jun 2009||Hall David R||Retention for Holder Shank|
|US20090183919 *||31 Mar 2009||23 Jul 2009||Hall David R||Downhole Percussive Tool with Alternating Pressure Differentials|
|US20090236148 *||28 May 2009||24 Sep 2009||Hall David R||Flow Guide Actuation|
|US20090255733 *||24 Jun 2009||15 Oct 2009||Hall David R||Lead the Bit Rotary Steerable System|
|US20090273224 *||30 Apr 2008||5 Nov 2009||Hall David R||Layered polycrystalline diamond|
|US20090294182 *||6 Aug 2009||3 Dec 2009||Hall David R||Degradation Assembly|
|US20100000794 *||11 Sep 2009||7 Jan 2010||Hall David R||Lead the Bit Rotary Steerable Tool|
|US20100059289 *||16 Nov 2009||11 Mar 2010||Hall David R||Cutting Element with Low Metal Concentration|
|US20100065332 *||16 Nov 2009||18 Mar 2010||Hall David R||Method for Drilling with a Fixed Bladed Bit|
|US20100065334 *||23 Nov 2009||18 Mar 2010||Hall David R||Turbine Driven Hammer that Oscillates at a Constant Frequency|
|US20100089648 *||16 Nov 2009||15 Apr 2010||Hall David R||Fixed Bladed Bit that Shifts Weight between an Indenter and Cutting Elements|
|US20100108385 *||23 Nov 2009||6 May 2010||Hall David R||Downhole Jack Assembly Sensor|
|US20100326740 *||26 Jun 2009||30 Dec 2010||Hall David R||Bonded Assembly Having Low Residual Stress|
|US20110042150 *||29 Oct 2010||24 Feb 2011||Hall David R||Roof Mining Drill Bit|
|US20110048811 *||27 Jun 2010||3 Mar 2011||Schlumberger Technology Corporation||Drill bit with a retained jack element|
|US20110080036 *||8 Dec 2010||7 Apr 2011||Schlumberger Technology Corporation||Spring Loaded Pick|
|US20110180324 *||31 Mar 2011||28 Jul 2011||Hall David R||Sensor on a Formation Engaging Member of a Drill Bit|
|US20110180325 *||31 Mar 2011||28 Jul 2011||Hall David R||Sensor on a Formation Engaging Member of a Drill Bit|
|USD620510||26 Feb 2008||27 Jul 2010||Schlumberger Technology Corporation||Drill bit|
|USD674422||15 Oct 2010||15 Jan 2013||Hall David R||Drill bit with a pointed cutting element and a shearing cutting element|
|USD678368||15 Oct 2010||19 Mar 2013||David R. Hall||Drill bit with a pointed cutting element|
|U.S. Classification||175/389, 175/419|