US1896703A - Core drill - Google Patents

Description

Feb. 7, 1933 C. A. DEAN CORE DRILL Filed May 28, 1930 3mm; Charles uZDeaw,

Patented Feb. 7, 1933 PAT ENT OFFICE m A. nm, BAIEBSIIELD, CALIFORNIA 001m name.

Application filed Kay 28,

drilling have employed a rotary drill such that the core is contained in the drill barrel.

After removal from'the boring, the core has been extracted either by pushin it from the barrel by a powerful screw or y pumping out the core hydraulically. The first method is exceedingly laborious, while the second destroys the full value of the core by .5 leakage of water past the hydraulic pusher head. Both require special and powerful equipment and involve cumbersome manipulation of the heavy drill elements. Moreover, secrecy is difiicult as to the nature of the sam- 2 ple, and the sample itself often is deformed so' as not to present a correct picture of the strata being studied. Similar difliculties are encountered by other previous methods, particularly, where a more or less laborious dismantling of the drill has been involved.

An object of this invention is to improve core drilling structures to obtain more simple core retention and extraction; also to obtain a more eflicient cooperation of parts, so

that the core sample may resent a more accurate picture of the dril ing. Specifically, an improved core-container assemblage is contemplated by the invention. Also there results a new mode of extracting the core from the drill barrel. In particular the invention pertains to an improved removable liner for traction more fully set forth herein.

In a specific embodiment, the invention may be illustrated by the rovision of a light gage core container. Preferably, this is free to rotate easily within the core barrel, yet prevented from being pushed into the barrel.

Also there is provision torelieve the core from v such pressure as'mightalter the natural con dition of the sample; or impede its extraction from the barrel. The arrangement further requires only the removal of a simple key 5 element, for instance'the core cutter proper,

1m. Serial No. 456,686.

to permit easy extraction of the container with the sample concealed against unauthorized inspectiom An embodiment of this invention is illustrate'd by the accompanying drawing.

Figure 1 is a vertical section of an assembled drill.

Figure 2 is a horizontal section along the line 22 of Figure 1, through the lower part of the drill sub, core barrels and core retainer.

The pilot drill or core cutter proper is designated as 1. This isremovably secured to an outer or main barrel 2 of the tool. Preferably, as shown, the cutter is screwed into a collar 3 'while the collar is threaded to the barrel 2. Threaded externally to the bottom of the collar above the cutter 1 there is shown a reamer or hole size cutter 4. In some forms of the invention the cutter 1 could be threaded directly to the reamer 4 but this particular fastening is not the essencev of this invention. An'essential is that by a simple operation the interior of the drill barrel is exposed so that a separate core container 5 may be inserted and removed. As shown, the pilot cutter in place serves to hold the container in normal position, and removal of the container requires first only that the relatively light pilot drill be unscrewed from the sub or collar 3.

An inner core barrel 6 preferably is retained within the collar 3 to encircle and protect the'core container. In the particular embodiment illustrated, this inner core barrel is screwed into the collar, and at it's top is provided with a taper seat. the core barrel, and to the combinations of parts and to the improved art of core ex- The collar 3 is of less internal diameter at its lower portion than at the upper, since the upper portion is threaded internally to receive the outer core barrel. The core cutter 1 is threaded into. the collar so as to provide a support for the container 5. Prefer ably an external flange 7, secured to the lower end of the container serves to support the container and also to limit its up and down ,motion. In the embodiment illustrated the extent of upward motion is determined by the lower end of the inner core barrel or by' the inner diameter of the collar above the flange, as the case may be.

The core container need be only of light material, for it is subjected to very little strain, particularly if combined with other features of the invention, to be described.

Tin sheet has been used, and light gage metal in general is satisfactory. In commercial practice the term sheet has an accepted significance to designate. metal below approximately one-eighth of an inch thick. With such material, the container may be split by hand with a small wire retained inside its walls, or by a hatchet or light mechanical cutter. In some instances a boiler flue is suit-, able. The range of materials will be a matter of choice, and need not necessarily be metal; this invention makes possible a satisfactory core container of less strength than heretofore has been necessary.

Preferably the core container is a single cylinder intact, designed to be cut or otherwise opened lengthwise when the core finally is inspected. Split or sectional types wit suitable fastening, are possible, but should be of such construction that no impediment is offered to the rotatability of the container in the inner core barrel during drilling, nor to the simple extraction of the container and core as a whole. Freedom of rotation, absence of jamming, and ease of extraction, are features of this invention with respect to the core retainer.

Suitably positioned between the core cutter and the container flanges 7, is an annular element bearing spring prongs 8 to project into the container. In operation the core by pressing back these prongs is held in a friction grip. In the claims this is designated as a core retaining device.

Between the inner and outer core barrels 40 is an annular space 9 connected to conduits -1O in the upper tool portions and communicating below with conduits 11 through the sub 3 and preferably also through the reamer blades 4. Thus fluid may be pumped to 4 the cutting members. In prior practlce the hydraulic pressure of this fluid acted detrimentally on the core. For this reason the conduits are provided to cooperate with the upper joint of the inner core barrel in 50 keepin the fluid pressure from the upper part 0 the core or core container. In order further to relieve the core or core containerfrom the indirect effects of the hydraulic pressure through entrapped fluid, a conduit 13 through the upper tool portion provides communication between the up er portion of the inner core barrel 5 an an upper portion of the drill hole, preferably as shown at approximately such upper level of the inner drill barrel as is at or above the top of the core on removal, such as through the upper drill head.-

, In operation the core as it is cut feeds into the core container and there is held and protected. The container will provide for such length of core as is desired. During the cutting there will be such rotation of the cutter dinarily, a new container is inserted and the drilling continued after but a minimum loss of time.

Where the container flange is at the bottom it serves further as a means to grip for removal of the'container, but other conformations preferabl toward the bottom end of the container li ewise will facilitate extraction, and limit vertical play of the container. It will be observed that in order to avoid crushing of the container there is no pressure imposed downwardly upon its upper positions.

It may be noted that the elements of this drill are simple and maybe assembled or replaced in a simple manner. They are separate so that parts may be replaced easily, but except the pilot cutter need not be removed other than for re lacement.

Modifications rom these illustrative embodiments will be within the scope of this invention. For instance features thereof may be utilized in other than rotary drills. Also the position of the bearing flange may be altered, and other means to be grasped be provided. Other features likewise may be varied within the scope of the appended claims. The invention has been set forth in accordance with the patent statutes; what particularly is claimed is r 1. A core. drill having a tubular drill barrel, and a thin gage core container extending freely and loosely into said barrel and freely withdrawable therefrom with vertical play limited solely through the conformation of the bottom portion ofsaid core container, and a wall surrounding said container to protect it from external pressure upon its own walls.

2. A core drill having inner and outer drill barrels, and a thin gage core container extending freely and loosely into said inner barrel and freely withdrawable therefrom with vertical play limited solely through the conformation of the bottom portion of said core container.

3. In combination, a core drill having inner and outer drill barrels, a thin gage core container extending freely and loosely into said inner barrel and freely withdrawable therefrom with vertical play limited solely by a flange at its bottom,a detachablecore bit supporting said core container, and.'acore gripping device retained at the bottom of said core container by means preventing locking engagement between said core gripping device and said core bit. is

6 4. In combination a core drill comprising an upper drill head roin which depend inner and outer drill barrels embodying a fluid conduit having communication with the drill ing surfaces, a detachable core bit having 10 exposed portions to facilitate detachment, a sheet metal core container-extendin freely and loosely into said inner barrel an freely withdrawable therefrom, said core container having rotary play and being limited in '1 vertical play solely by a flange at its bottom that is supported between said detachable core bit and said inner drill barrel, the upper interior-of said cor'e container communicating through said upper drill head with the exterior of said drill but closed to said fluid conduit.

5. In a core drill comprising spaced'inner and outer drill barrels and a thin gage core container extending freely and loosely into said inner barrel and freely withdrawable' therefrom with vertical play limited solely by a flange at its bottom, a removable collar secured to the bottom of said outer core barrel and having an annular conduit communieating with the space between said inner and outer drill barrels, reamer blades detachably secured to said collar and having spaced con' duits communicating with said annular con- 7 duit, and a detachable pilot drill secured to said collar to .support said core container flange and having portions extending below said reamer blades to facilitate detachment of said pilot drill and to prevent washing of the core by fluid flowing from said reamer blades. a

In witness whereof I aflix my signature.

CHARLES A. 4

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