US1850386A - Core retainer - Google Patents

Description

March 22, 1932. C. A DEAN 1,850,386

CORE RETAINER Filed July 19, 1930 K Szlg 7 l is 3mm/tor @Aar/es cmq Patented Mar. 212, i932 i UNITED STATES CHARLES A. DEAN, OF IBAKERSFIELD, CALIFO'BNlA f CORE RETAINER Application. led Iuly 19, 193i). Serial No. 489,124.

This invention relates to improvements in earth boring,` and particularly to drills for obtaining sample cores. 4

Broadly, it is an object of this invention to provide meansfor obtaining and for retaining a core positively in a drill and to combine exibility with certainty of action in the core retaining means. This is accomplished by an improved form and mounting of grip or dog to be projected into the core in a controlled manner, and by other improvements herein Set forth.

Heretofore drills have been designed to cut cylindrical or other portions through strata to be sampled, and to retain such portions within the drill. lFrequently in present day operations these samples are taken many thousands of feet below the surface and under conditions that continually tend to destroy the accuracy, if not the existence, of the sample. of the drill, for example, usually are surrounded by viscous fluid, such as mud, that tends to counteract the action of such means as heretofore have been pro-vided to preserve a core while it is being raised tothe surface. Further, a core frequently remains fastened or cemented to the bottom of the drill hole to such extent that either it is not extracted at all, or else is broken in being raised.- These factors are illustrative of variouscauses of uncertainty that interfere with dependable sampling in earth drilling, as for example in oil well drilling.

In core taking, various types of drill may be employed, such as a churn drill or a rotary drill. For the purpose of illustration, reference is had to a rotary drill of the type frequently used in oil well drilling, but it will be apparent that suchreferences are illustrative rather than limiting, and that the principles of this invention may be extended within the purport of the claims hereinafter presented.

Referring to the drawings z Fig. l'represents in general assembly a vertical section of the rotary type of core drill, showing the form and arrangement of one form of core retaining means.

The sampling or cutting portions Fig. 2 is a section'ialong the line 2-2 of Fig. 1.

Fig. 3 is a side elevation of a core retaining element and of that portiongof the drill is illustrated as being separable. It carries splines or feathers 7 engaging complementary positions of the outer barrel, as shown in Fig. 2, both to guide the inner barrel to a pre-designed position and to impart rotary motion to it. To the lower end of this core barrel a pilot or core cutter Sis' secured in any desired manner. This core cutter and container thus is rotatable with the outer barrel but free to rise and fall relatively to it.

Through an appropriate lower portion of the inner core barrel there are provided openings 9, suitably spaced and preferably upwardly directed inwardly. Through these are inserted pins or dog elements 10. Suitabley forms of these dogs are illustrated as having spherical heads, but cylindrical or other terminal portions may be provided, so that these elements may project through the inner barrel and be free to pivot at their ,bearing points. Through the outer barrel are provided openings 11 preferably registering with these dogs, such that these dog-elements may be inserted'or removed therethrough, and also preferably may pivot therein.y Appropriate screws or bushings 12-are then inserted to complete a housing or seatfor the dogs andV to retain them.

lt will be observed from this description and the accompanying drawings that in the example given the head of the core gripping dog is engaged by the housing or pocket of the outer drill barrel, and that the piercing end of the dog is -elongate and relatively inflexible and is of substantially uniform contour, and that as the dog pivots, it slides so that its end pierces the core alongksubstantially a straight line. Thus the dog is relatively strong and is adapted to pierce'a core and to be withdrawnpositively therefrom with a minimum of injury to the core.

l The-usual space or fluid conduit 13 between the inner and outer barrels communicates with the pivot portion or seat for the dogs so` that the pivot is kept free by the wash of fluid, this washing action being facilitated by the circular contour of the head ofl the dog. Various forms of housing or bushing and of conduit connections will serve to accomplish this purpose.

In operation, the form of drill illustrated will be rotated with the pilot drill resting or pushed against Ithe' bottom of the drill hole. The core cylinder thus will be at an upper position relatively to the outer barrel.

, The dogs 10 will be pivoted, their outer ends pulled downwardly Aby coaction with the outer barrel and the inner ends withdrawn into the openings of the inner barrel. Thus the core may be cut and fed into the inner barrel while the dogs by positive action are kept withdrawn.

When the whole drill israised the Weight of thecore and inner barrel bring that barrel to a lower position with respect to the outer barrel and thus positively rotate the gripping ends ofthe dogs into the core body. Should the pilot drill again be pressed against the bottom of the drill hole, these dogs will be withdrawn and the drill may be rotated without interference between the core and the dogs. l

In some instances the core becomes cemented or otherwise remains fastened to the bottom of the drill hole. This invention permits counteracting of this fault by appropriate action of the dogs. Any slight or desired raising of the drill will tend to project the dogs into the core and as the drill then is rotated these dogs will gradually and controllably cut the core loose Afrom the bottom. They then will retain it as normally.

It will be observed that appropriate de- -sign of the splined sleeve will provide not only suitable guides for the dogs, but also will communicate rotary motion between the outer`and inner core barrels. In some types of drill this latter action may not be necessary, as in a churn drill.

The assembly as illustrated in Fig. 1 is particularly desirable since it permits ready removal of the inner barrel from the outerA barrel without removing the individual dog elements. The core suitably may be extracted from the inner barrel in either direction. Other assembly will be possible with various modifications of drill. Also positively actu ated dogs may be provided for existing drills. Nor is this invention restricted to the preferred form or mounting of dogs illustrated herein, but other kpositive actuation will be within `the scope of the appended claims except as limited by the prior art.

In accordance with the patent statutes illustrative embodiments of this inventionhave been described, but the invention is not limited thereto, within the terms of the claims,

except as limited by the prior art. l,

of a drill barrel and with completely cylindrical outer walls extending to its lower end, an inner tubular core container telescopically mounted within the collar, with interior splined connecting means intermediate the wallsofuthe two to prevent relative rotation, and core dogs having a core-piercing end and having a head end mounted within the collar for engagement thereby to cause the head both to. rise and to fall, the core container and the dogs being adapted for the core-piercing end to slide lengthwise into and from a core on corresponding relative vertical movement between container and outer collar.

3. A core drill comprising a tubular collar with its upper portion attachable to the end of a drill barrel, and withcompletely cylindrical outer walls extending to its lower end, an inner tubular core container telescopically mounted Within the collar, with interior splined connecting means intermediate the walls of the two to prevent relative rotation,V

head end pivotally mounted within the chambers and positively engageable therein `by the collar for causing the head both to rise and to fa1l,the'core container and the dogs being adapted for the core-piercing end to slide lengthwise into and from a core on corresponding relative vertical movement between container and outer collar.

4. A core drill comprising a tubular collar with its upper portion attachable to the end ofl adrill barrel and with completely cylindrical outer walls extending to its lower end, an inner tubular core container telescopically mounted within the collar, with interior splined connecting ymeans intermediate the walls ot the two to preventrelative rotation, chambers in the inner wall of the collar, core dogs having a core-piercing end and having an integral'arcuate head end pivotally mounted' within the chambers and positively engageable by the collar for causing the head both to rise and to fall, the walls of the core container having openings extendin upwardly from the collar and adapted witl dogs 'for the core-piercing end to 'slide into and from a core on corresponding relative verprojecting over the face of the openings to divert liquid from entering, and/a fluid assage having an outlet below the core ogs and extending between core container and outer collar in communication with the coredog heads to maintain freedom of pivotal action.

5. A core drill, comprising a tubular collar with its upper portion attachable to the end of a drill barrel and with completely cylindrical outer walls extending to its lower end, reamer blades attached to the bottom of the collar, an inner tubular core container mounted telescopically within the collar with intrior splined connecting means intermediate the walls of the two, to prevent relative rotation, chambers in the inner wall of the collar, core dogs having a.5 core-piercing end and having a head end pivotally mounted Within the chamber and positively engageable by the collar for causing the head both to rise and to fall, the core-container having openings with a wall thereof extending upwardly from the collar and adapted with the dog for the corepiercing end to slide into and from a core on corresponding relative movement between container and outer collar, and core-cutting blades below the reamer of less diameter than the reamer and detachably terminating the core container. Y

6. A core drill, comprising a tubular-collar with its upper portion attachable to the end of a drill barrel and with completely cylindrical outer walls extending to its lower end, reamer blades attached to the bottom of the collar, an inner tubular core container mounted telescopically within the collar with in-v terior connecting means intermediate the walls of the two to prevent relative rotation, a chamber in the inner Wall of the collar, core dogs having a core-piercing end and having a head end pivotally mounted within the chamber and positively engageable by the collar for causing the head both to rise and to fall, the core-container having openings with awall thereof extending upwardly from the collar and adapted with the dogs for the core-piercing end to slide into and from a core on corresponding relative movement between container and outer collar, arluid passage having an outlet below the core dog and extending between core container and outer collar in communication with the core-dog heads to maintain freedom of pivotal action,`

and core-cutting blades detachably terminating the core container below the reamer.

In witness whereof I aix my signature.

CHARLES A. DEAN.

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