US2660483A - Percussive drift drill - Google Patents

Description

Nov. 24, 1953 Filed July 22 1949 Fig. l

o. PHIPPS v 2,660,483

PERCUSSIVE DRIFT DRILL 2 Sheets-Sheet l Fig.2

INVENTOR. Q RVILLE PHI PPS A TTORNEY Nov. 24, 1953 Filed July 22 1949 O. PHIPPS PERCUSSIVE DRIFT DRILL 2 Sheets-Shes; 2

' INVENTOR.

ORVILLE PH PPS MM ATTORNEY Patented Nov. 24, 1953 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to theartandpractice of percussive rock, and ore drilling for the development of deep blast holes therein, and more particularly to such drilling performed in a nonvertical direction-and hence productive of frictionaldrag between the drill stem and bit assembly and thewalls of, the drilled hole, and has an object'to provideimproved cooperating means and facilities constituting a percussive drill bit andgstem assembly employable with conventional actuating; means and adjuncts to enhance the economy and efiiciency of such drilling operations.

A further objectof the invention is to provide animproved construction and separable interrelation of drill bit; coupler, and stem sections constituting an assemblyoperable for the percussiv drifting of -deep blast holes in association with conventional actuating means and adjuncts. A- further-object of the invention is to provide improved means for the intercoupling of bit and drill stem sections in an assembly operable for the percussive drifting of deep blast holes with celerity and efiiciency. p A further object of the invention is to provide improvedmeans for the intercoupling of bit and drill stemsections in a percussive drift drill'assembly characterized by minimum side friction and adequate bore-scavenging capacity.

A'further object of the-invention is to provide an improvedpercussive drillassernbly convenient of operative, manipulation in the development of drift holes at various inclinations and to various desired depths, that is especially susceptible of length variation at. will, that is rugged, durable, and efficient inuse, and that is adapted to facile production in a wide range of desired sizes by known means and available agencies.

- With the foregoing and other objects in View, my. invention consists in the construction, arrangement; and'operative combination of elements hereinafter set forth, pointed out in my claim, and illustrated by-the, accompanying drawings, in which- Figural is a somewhat diagrammatic elevation of a representative embodiment of the invention as assembled and associated wtih conventional actuating means ready for practical use. relatively enlargedv scale, of the bit end of the ,drill assembly according to Figure l in operative-relation with a drift hole developed. Figure 3 is afragmentary, detail elevation, on a further enlarged scale, of a separable joint char;v

acterizing the. drill assembly shown in the pres shown, the numeral l0 designates a conventional Figure 2 is a fragmentary elevation, on a I ceding views. Figure, 4. is a fragmentary, detail section,,taken substantially on the indicated line 4-4 of Figure 3. Figure 5 is a transverse sec,- tion taken onthe indicated line 5-5 of Figure 4. Figure 6' is a fragmentary, detail elevation; partly in section and onthe same scale asFigures 3, 4 and-5, of" the bit end of the assembly shown inFigures l and 2.

In the percussive driftingof blast and analogousholes at variousinclinations to the, vertical inrock and ore bodies; it is conventional practice to use, a mechanical hammer powered. by hand, fluid pressuraor electricity, to percussively drive, advance, and simultaneously rotatea drill assembly comprisedirom a plurality oiinterconnected stem sectionscarryinga bit onthe section free end remote. from the hammer; said sections and bit being. separably interrelated. for simultaneous rotation andreciprocation and being characterized by. a continuous axial bore opening through thebit for the. transmission of iiuid. through thewhammeriand drill assembly, to ejection fromthe bit for cooling of, the bit work ing face andscavengingof the bore under, de- 1 As will be manifest, non-vertical velopment. driftingby means of conventional drill'assemT blies is productive of a drag of the assembly against the lower wall ofthe', bore as the depth of the latter increases, thus lowering the percussive em'ciency of'the hammer evidenced at the face of thebore, impeding the effectiveness of bore scavenging, and rapidly wearing the frictionally-engagedsurfaces of the assembly, and

the instant, invention is hence directed. to the provisionof a novel and imp-roved'percussive, drill assembly construction incorporating allofjthe ade vantages of conventional analogous arrangements and free from the operative'disadvantages just noted; 1

Inthe construction, of the. improvement as mechanical hammer operable by means ofifluid pressure through a line H to percussivel'y. drive and simultaneously rotate adrill assembly end; engaged. in its chuck l2. and supportedthrough a guide It in a usual, manner. iscarried by and for altitudinal and angularadjustment relativeto the usual mountingpost. Hi and is, served by. the customary line [5 'where-j through fluid under pressure,. preferably. water,

may be supplied through the hammer and'it schuck [2 to the axial bore of the drill assembly, and. a separate fluid pressurev line ifiscrvesthe mechanism of the-hammer effective-t0;axiallyad: Vance the chuck. lg, and drill; assembly engaged The, hammer l0 therein. All of the foregoing is conventional construction typical of usual percussive driftdrilling operations and in and of itself forms no part of the instant invention, being herein illustrated and described as but representative of known agencies and techniques susceptible of efflciency enhancement through association with the improvements hereinafter elaborated.

The improved drill assembly of the invention is adapted to operatively mount and percussively drive a bit of the type shown and described in my United States Patent No. 2,507,221, dated May 9, 1950, which bit is characterized by a generally frusto-conical body I1, tungsten-carbide alloy blocks l8 inset as the cutting elements of its working face, an axial, internally-threaded socket I9 opening through its lesser end for mounting engagement with a drill stem section, flutes 2!] longitudinally interrupting its exterior Wall and opening through its working face between the blocks It for scavenging clearance of cuttings, and flow channels 2! communicating between the socket 19 base and outlets in the flutes 20 and bit working face for ejection of cooling and scavenging fluid transmitted to the bit through the stem sections, and the said improved assembly is comprised, in addition to the bit, from an appropriate number of stem sections 22 and section couplers 23, hereinafter specifically described.

The stem sections 22 are alike, save as to length which may vary within the contemplation of the invention from a few inches to a maximum approximating five feet, except for the section unit engageable with the hammer chuck 12 which is modified at One end in any conventional manner suited to driving cooperation with said chuck, and each presents, in a rigid, integral unit, a straight shaft body of desired diameter, length, and exterior surface contour, a threaded stud 2d coaxial with and projecting from each end of said body, an annular bearing shoulder perpendicular to the body axis marking the junction of each'body end with the associated stud 24, and an axial bore or channel 25 traversing and opening through the body and associated studs. The end of the initial section 22 remote from section engagement with the chuck I2 is furnished with a stud Hand shoulder 25 identical with the corresponding elements of the other stem sections and is provided with the bore or channel 26, and the sections 22 employable in a given operation will include a variety of section lengths appropriate for the constitution of variable length drill assemblies adequate for initiation and development of the desired drift hole. The ends of the stem sections 22 providing the shoulders 25 may be. expanded relative to the body portion therebetween, as shown, or may be of the same diameter as said body portion, as may be determined by factors of requisite strength and pertinent.

economy. Interrelation of the sections22 in a coaxial assembly of desiredlength is accomplished through the agency of the couplers 23, one of which is employed to complete each joint of the assembly intermediate the bit mounting and driving engagement with the hammer chuck I2. 7 Each coupler 23 is a rigid, integral unit developed on, in, and about a generally cylindrical body of a diameter equalling that of the stem shoulders 25 and a length more than twice the length of a stem stud 2d. Ends of the coupler 23 body are finished perpendicular to the body axis for abutting enga-gement'against shoulders 25 of the stem sections 22,'and each of said coupler body ends is intersected by a coaxial, internallythreaded socket 21 of a depth somewhat exceeding the stud 24 length and adapted to cooperatively accommodate such stud; inner ends of said Sockets 2? in a given coupler being spaced apart by a partition integral with the coupler body through which an axial throat 28 opens to continue the bore or channel 26 of the sections 22 interconnected by the coupler. Exteriorly, each coupler 23 body is formed with a plurality, at least three, of like, angularly-spaced, longitudinal channels defined by and opening radially between like, integral ribs 29 outstanding from and longitudinally of the body in paired relation and in such convexity of their exterior margins as results in a merging of the rib ends with the body contour at the ends of the coupler and a maximum channel depth at the coupler mid-portion; the rise of said ribs away from the coupler body being definitive of a maximum coupler diameter at the unit mid-section approximately one-eighth of an inch less than the working face diameter of the bit to be employed with the assembly. In the midlength of each channel defined between the paired ribs 2s. a block 30 of hard, abrasionresistant material, such as tungsten-carbide alloy, is closely fitted to bear against the channel floor and rib faces and permanently secured, as by means of welding or brazing, in an outer surface contour conforming to the rib 29 convexity and the coupler transverse circular outline determined by said ribs. The blocks 38 preferably do not extend the full length of their mounting channels and are end-beveled, as shown, well short of the corresponding channel ends. The ribs 29 defining adjacent sides of the angularlyspaced channels outstand in an angular divergence productive of a flute or channel 3! longitudinally of the coupler wherethrough material and fluid incident to scavenging of the drift hole may pass during operation of the assembly.

The external threads of the studs 24 and the mating internal threads of the bit socket is and coupler sockets 2'! may, of course, be of any type and design suited to accomplish the interengagements for which they are provided, but operative advantages result when said threads are of the non-binding, sinuously-proflled type in the specified diameter and length proportions set forth in my pending application for United States patent, Serial No. 681, filed January 6, 1948, and now abandoned. Whatever type and design of thread may be employed for the studs 24 and their receiving sockets, it is immediately apparent that all such threads should be similarly pitched in a direction so correlated with that of chuck l2 rotation as to maintain the threaded joints in tight interengagement during operation of the drillassembly, and that the depths of the studreceiving sockets should exceed the stud lengths to assure percussion-transmitting, bearing engagement of the stem shoulders 25 and the asso ciated coupler 23 or bit i? ends.

In the operation of the improved drill assembly constructed and organized as shown and described, it is readily to be seen that the couplers 23 serve to unite the stem sections 22 and bit I! in a solid, coaxial assembly highly effective in the transmission of forces applied through the hammer It and adapted to the pressure supply of cooling and scavenging fluid to the bit working face.- i The use of the couplers 23 in a diameter slightly less than that of the bit working lacs permits the rotational and reciprocating frictions incident to assembly actuation to be concentrated on the limited areas of the wear blocks 30 as the latter ride on the drift hole walls, thereby materially reducing the operational friction loss, minimizing wear damage to the equipment, preserving alignment of the elements for efiicient force transmission, and maintaining clearance between the hole lower wall and the stem sections 22 wherethrough effective scavenging may be had with the aid of the bit flutes 20 and coupler flutes 3|.

Since changes, variations, and modifications in the form, construction, and arrangement of the elements shown and described may be had without departing from the spirit of my invention, I wish to be understood as being limited solely by the scope of the appended claim, rather than by any details of the illustrative showing and foregoing description.

I claim as my invention:

In a coupler for percussive drill string sections having an axially-elongated, generally-cylindrical body connectible with and as a coaxial link between adjacent section ends, a flow channel axially of said body, and a plurality of like, convex rib units outstanding from and longitudinally of said body in a uniform angular spacing clefinitive of straight, unobstructed flutes therebetween, means for minimizing frictional drag and coupler Wear effects incident to percussive drill string actuation within a well bore, saidmeans comprising, a straight channel centrally and exteriorly intersecting the full length of each of said rib units to condition the unit exposed surface for minimum frictional coaction with well bore walls as a pair of narrow, spacedly-parallel, convexly-margined rib elements end-merging with the body ends, a separate, preformed, alloy wear block of less length than the rib elements fitted to seat within and to fill the central portion of each unit-intersecting channel between the rib elements thereof in conforming engagement of its side and bottom surfaces with the channel and rib element surfaces contacted thereby, a permanent bond uniting the full contacting areas of said block and its mounting, and an exposed wear surface on said block conformed to the exposed margins of its associated rib elements.

ORVILLE PHIPPS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,477,855 Thurston Dec. 18, 1923 1,518,960 Bowser Dec. 9, 1924 1,814,271 Vaughn July 14, 1931 1,912,854 Osgood June 6, 1933 2,247,564 Turner July 1, 1941 2,263,579 Hokanson Nov. 25, 1941 2,288,124 Creighton June 30, 1942 2,298,049 Gardner Oct. 6, 1942 2,334,350 Neuhaus Nov. 16, 1943 2,337,711 Crake Dec. 28, 1943

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