US3169590A

US3169590A - Apparatus for drilling large diameter holes

Info

Publication number: US3169590A
Application number: US92419A
Authority: US
Inventors: Orrin C Thatcher
Original assignee: Ideas Inc
Current assignee: Ideas Inc
Priority date: 1961-02-28
Filing date: 1961-02-28
Publication date: 1965-02-16
Anticipated expiration: 1982-02-16

Description

Feb. 16, 1965 o. c. THATCHER 3,169,590

APPARATUS FOR DRILLING LARGE DIAMETER HOLES Filed Feb. 28, 1961 2 Sheets-Sheet 1 INVENTOR. ORR/N GTHATcHEn ATTORNEYS Feb. 16, 1965 o. c. THATCHER 3,159,590

APPARATUS FOR DRILLING LARGE DIAMETER HOLES Filed Feb. 28, 1961 2 Sheets-Sheet 2 INV EN TOR. Onnm C. THATCHER .AT TORNE Y3 United States Patent 3,169,590 APPARATUS FGR DRILLING LARGE DIAMETER HOLES Orrin C. Thatcher, Stanford, Mont. Ideas Inc, 2327 ltith Ave. 53., Great Falls, Mont.) Filed Feb. 28, 1961, Ser. No. 92,419 1 Claim. (Cl. 175-94) My invention relates to novel apparatus for drilling of cylindrical openings of a given depth in the earths crust, for numerous purposes such as underground silos or storage compartments, concealed gun mounts, imoedded missile pads and the like.

When drilling or forming openings for missile silos and the like, the variations in hardness and kind of earth and rock formations (such as sand, soft shale, limestone, hard rock, etc.) which may be located within the proposed opening often present problems which hinder the etficient drilling of the opening. Since portions of the relatively heavy drilling head may be resting upon relatively soft ground and other portions thereof may be on hard rock or the like, one of such problems is that the support for the drilling head must be constructed so as to resist bending moments and stresses imparted thereto by portions of the heavy drilling head which are effectively cantilevered with respect to the support.

The primary object of my invention is the provision of novel apparatus of the type immediately above described which overcomes the above noted problems and which may be used to drill a cylindrical opening in the rock formations of the earths crust of a greater diameter than heretofore thought possible, and with a minimum of man-power and expense.

A further object of my invention is the provision of apparatus of the type above described which is not unduly expensive to produce and which may be installed in operative position and removed from a drilled opening with a minimum of skill and experience.

A still further object of my invention is the provision of apparatus of the type above described which is rugged and durable in construction and which requires but a minimum of maintenance.

The above and still further objects of my invention will become apparent from the following detailed specification, appended claim and attached drawings.

Referring to the drawings wherein like characters indicate like parts throughout the several views:

FIG. 1 is a schematic view in vertical section, illustrating preliminary steps in the practicing of my invention;

FIG. 2 is a view corresponding to FIG. 1 but showing my novel equipment in side elevation and still illustrating further steps in the practice of my invention;

FIG. 3 is an enlarged detailed vertical section of FIG. 2;

FIG. 4 is a View in horizontal section taken on the line 44 of FIG. 3;

FIG. 5 is a fragmentary view in section taken on the line 55 of FIG. 4; and

FIG. 6 is an enlarged fragmentary sectional view taken on the line 6-6 of FIG. 3.

Referring with greater particularity to the drawings, the first step in my method comprises the drilling of a vertical pilot hole A in the earths crust X, and for this purpose it is obvious that any suitable rotary rock drill bit may be utilized. For a purpose which will hereinafter be explained, it will be noted, by reference to FIG. 1, that the depth of the pilot hole A is greater than that of the proposed opening B to be drilled by my method and with my novel apparatus.

The next step in my method comprises placing into the vertical pilot hole A an elongated, preferably cross-section cylindrical axle 1 the diameter of which, as shown in FIG. 1, is considerably smaller than that of the pilot hole of the drilling head 5.

A. Furthermore, it will be noted that the axial dimensions of the axle it are such, with respect to the pilot hole A, that the upper end in thereof projects considerably above the surface of the ground X for a purpose which will hereinafter become apparent. After centering the axle 1 within the pilot hole A, so as to define an annular space 2 therebetween, the next step in my method resides in the anchoring of the axle 1 within the pilot hole A. This may be done by the filling of said space 2 with concrete or grout 3, said grout 3 extending completely from the bottom 4 of the pilot hole A to the surface of the earth X. In this manner the axle l is securely anchored within the earth X for the carrying out of the remaining steps of my method with my novel apparatus each of which is hereinafter described.

After suitable hardening of the grout 3, my novel drilling head, identified in its entirety by letter 5, is inserted over the extended upper end in of the axle l, as shown in FIG. 2. By reference to FIG. 2, the problems presented by the portions of the drilling head 5 resting on relatively soft ground may Well be appreciated. Drilling head 5 includes an annular horizontally disposed base plate 6, upstanding outside frame members '7, and upstanding central tubular bearing sleeve 3, loosely encompassing the axle 1, and upper frame members or braces 9 connecting the upper end portions of the outer frame member '7 of the bearing sleeve 3. Suitably journalled in bearing brackets it) depending from the under surface 11 of the annular base plate 6, on axes radiating from the axle l, are circumferentially spaced elongated roller bits 12 formed to provide a plurality of generally axially extended circumferentially spaced cutting teeth 13. Rotary movements are imparted to roller bits 12 by any suitable means but preferably through a pair of motors or power units 14 mounted on the upper surface 15 of the base plate 6.

' Since the particular design of the power units 14 is not an important feature of this invention, further showing and description thereof is unnecessary. Rotary movements of the roller bits 13 obviously irnpart rotary movements to the drilling head 5 in its entirety.

It will be noted by reference particularly to F168. 3 and 4 that the power driven rotary bits 12 terminate at their axially inner end portions 16 in spaced relation to the axle 1 whereas their axially outer end portions 17 terminate in spaced relation to the outer peripheral limits 1% For the purpose of providing an uninterrupted cut between opposite side portions of the axle 1 and the outer peripheral edge 18 of the drilling head 5, I provide circumferentially spaced pairs of inner gauge bits 19 and outer gauge bits Zil. As shown, the pairs of inner and

outer gauge bits

19, 29, are spaced 180 with respect to each other and from the roller bits 12. The inner and outer gauge bits 1'9, Zll, are likewise mounted for rotation on axes radiating from the axle 1, and are provided with similar cutting teeth 13. The inner gauge bits 19 overlap the cutting void between the axially inner ends 16 of the power driven roller bits 12 and the axle 1, whereas the outer roller bits 29 overlap the cutting void defined by the axially outer end portions of the roller bits 12 and the outer peripheral edge 18 of the drilling head 5. Gauge

bits

19, 2%, are preferably idlers.

Supplementing gravity so as to cause the drilling head 5 to exert the desired amount of downward pressure upon the rock strata in which the drilling head 5 is being worked, I provide means to exert a downward pressure on the drilling head 5 relative to the anchored axle 1, and it will be appreciated that the axle 1 must therefore be Well anchored to resist the relative pull thereon by such means. Said means is illustrated as comprising an adjustable anchoring collar 21 which is slidably receivable over the upper end la in overlying relationship to the drill head 5. Anchoring collar 21 may be locked to the bearing 24 is journalled for rotation on the tubular bearingsleeve 23 and rotatively engages the under surface 25 of the anchoring collar 21. interposed between the thrust bearing 24- and the drill head 5 are circumferentially spaced expandable and retractable elements which are shown as well known double-acting fluid pressure cylinder mechanisms, represented generally by 26, the same being provided so as to exert a generally downwardly directed pressure on the drill head 5. As shown, the elements 26 include cylinders 27, the lower ends of which are secured to the drill head 5, preferably and as shown through the medium of the cross braces 9 thereof, as indicated at 21%.

Elements 26 likewise include pistons 29, the push rods of which are identified by The upper ends of the rods 3t) are connected to the thrust bearing 24 as indicated at 31. Fluid under pressure is introduced into lower portions of the cylinders 27 to extend the cylinder 27, through suitable conduits 32 extending between the lower end portions of the cylinders 27 and suitable well known hydraulic reservoir and pump means, the latter of which is partially shown at 33 in FIG. 3 as being mounted on and carried by the drill head 5; It is noted that the reservoir and pump means partially shown at 33 in FIG. 3 is independent of the power units 14, the former however not being an important feature of this invention and therefore being only briefly described herein. Escape of fiuid under pressure from the upper portions of the cylinders 27, so as to permit upward movements of the cylinders 27 and relative retracting movements of the plungers 3%) carried thereby, is achieved through the medium of suitable tubes 34. The control of the operation 05 the fluid pressure cylinder mechanism 26 may be by any'suitable and well known means, not shown.

Operation A drilling operation with my novel apparatus, assembled as shown in FIGS. 2 and 3, is as follows: With the push rods 30 retracted within their respective cylinders 27 the anchoring collar all is lowered into engagement with the annular thrust bearing 24, and the collar 21 is locked in said position through the medium of set screws 22. Fluid under pressure is then introduced into the cylinders 27 by way of the pump means 33 and the inlet tube 32, whereby to exert a predetermined amount of downward pressure of the drill head 5' against the underlying rock strata comprising the earths crust immediately surround ing the axle 1. Rotary movements are then imparted to the roller bits 12 through the medium of the power units 14, whereby to impart rotary movements to the drill head 5', as well as to the inner end idler gauge bits l9, 2%). In this manner an uninterrupted cut is effected between the axle l and the axially outer limits 35 of the gauge bits 20. It will be understood that a constant amount of pressure is maintained within the cylinders 27 so that a desired and constant downward pressure will be exerted by the drill head 5 upon rock strata being drilled, as the drill head 5 works its way downward therethrough. Obviously the precise amount of such pressure will vary with the density of the rock'strata being drilled.

Removal'from the bottom of'the pit or opening B of the chi s and rock dust'loosened by the

roller bits

12, 19, 20 may be effected by any suitable and well known means. For instance, water may be introduced into the bottom of the opening B-to form a Slurry, and removal of said slurry etfected by a suction hose or the like, not shown.

It will be noted, primarily byv reference to FIG. 5, thatthe primary function of inner roller gauge bits 19 is to drill and abrade away through the concrete or grouting 3 about the axle 1. Thus, when the desired depthof the opening B has been reached, the axle 1 is firmly supported in a verticalposition by means of'the concrete or grouting Sencompassing the lower end of the axle 1, below thebottom of the opening B.

While I have shown and described a workable form of my invention, I wish it to be specifically understood that the same may well be modified without-departure from the scope and spirit of the appended claim.

Whatl claim is:

Apparatusfor drilling into the earths crust a cylindricalopening of a given depth for the formation of an underground silo or the like, said apparatuscomprising an elongated axle of constant diameter andthe axial dimension of which is considerably greater than thatof the proposed opening, said axle beingadapted to be placed and secured within a previously drilled centrally located vertical pilot hole of a vertical depth greater thanthat of the proposed opening and with the upper end portion of said axle projecting above the upper elevation of said'opening, a drilling head slidably rotatably received upon the projectingupper end portion of said axle and having a drilling diameter corresponding to the desired-diameter of said opening, power operated meansfor imparting rotation to said head about said axle, and means for applying a generally downwardly directed pressure on said drilling head rela-' tive to the upper end portion of said axle, said means for applying a downward pressure on said drilling head comprising a vertically adjustable anchoring collar slidably received upon and releasably and adjustably secured to said axle in overlying relationship to said drilling head, and a generally vertically extensible and retractable device interposed between said drilling head and said anchoring collar.

References Cited in the file of this patent UNITED STATES PATENTS