US1737256A - Plug for core drills - Google Patents

Description

A. F. MCQUISTON PLUG FoRcoRE DRILLs Filed oct. 5, 19.2;5l

Nov. 26, 19,29.

Panarea Nov. 2s, 1929 vUNITED STATES PA'rEN-r OFFICE ARMEL IE"f MCQUISTON, OF TAFT, CALIFORNIA, ASSIGNOR TO ELLIOTT CORE DRILLING l COMPANY, A CORPORATION 0F CALIFORNIA PLUG FOR CORE DRILLS- Application led October 5, 1928. Serial No. 810,524.

My invention relates to the art of taking cores by the rotary method of drilling, being more speciically a plug for temporary and partial closure of the core receiving chamber 3 during the lowering of the drill into the hole. In core drills of the type used in rotary drilling, the. core receiving chamber is open at its lower end and during the lowering of the drill into the hole the rotary mud or circulating fluid, together with large particles of the formation, enters thevcore receiving chamber. Later when drilling operations are commenced, as the core enters such'chamber the Huid or mud is discharged from the top of the core tube or barrel through a valve. but any large pieces of formation accumulate in the top of the core barrel and pack therein, thereby-diminishing the core receiving length of the core chamber as such 0. material will not pass through the valve. Such material in some instances packs in the barrel to such an extent as to impede the entrance ofthe core into the barrel, resulting in failure to obtain a core typical of the forma- 5 tion being drilled. A

It is the principal object of my invention' to provide a collapsible plug of simple form andconstruction mountable in the core recelving opening of the core barrel which is 0 positively dislodged at the timethe drill is about to engage the formation.

Other objects and advantages will appear hereinafter from the following descrlption and drawings. Referring to the drawings which are for lllustrative purposes only Fig. 1 is a side elevation partly in section i of a core drill equipped with a form of my invention. f Fig. 2.is an enlarged vertical sectional view of the lower end of the drill shown in Fig. 1. Fig. 3 is an enlarged cross sectional view of the plug with the dart removed; and

,Fig. 4 is a perspective view of the parts forming a complete plug.

More particularly describing my invention yas illustrated in the drawings, 11 designatesl the outer barrel of a core drill to which is secured, at its lower end, a drill body having a drill head 13 threaded thereon. 'The-head lterminates at its lower end in a circular toothed cutter 14 .formed about a central core receiving opening 15 which' communicates vwith a centralcore opening 16 in the body 12 and the core chamber 17 of a core barrel 18. The core barrel 18 is spaced apart from the outer barrel to form a fluid circulation pas- .Sage 19 therebetween, such passage 19|having outlet ordischarge openings 20 formed in the body 12. The inner or core barrel 18 is provided at its upper end with a valve 21 which permits the circulative fluid or mud to be discharged therefrom as the core en- A ters the core barrel.

` In' addition to the circular cutter 14 the head 13 is povided with cutting blades 22 which may be -of any desired form.

' The plug may be termed a collapsible mem-k ber and is designed to t within the core reblocks as shown in Fig. 2 retains the plug in position in the opening 15 of the head and prevents dislodgment `of the plug from the' opening until the dart engages the bottom of the hole indicated at 30 in Fig-2 as hereinafter described.

vThe device operates as follows: The plug is placed in the drill in the position shown in, full lines in Fig. 2 with the lower end` of the dart extending ahead of the lower end lof the drill. The drill is then lowered into the hole and during sucl. lowering of the drill the plug excludes large particles from entering the core barrel. Theopening 31 between the two blocks 25, however, permits the circulatli)ng fluid or mud in .the hole to enter the core arrel.

of the blocks just described, but it is under`A stood that the adjacent faces of the' bloclxs the dart 29 strikes the bottom of the` may be made in dierent form as long as sufcient clearance is allowed between the blocksl to rmit such collapsing movement.

e blocks and dart may be made of any suitablematerial such as wood, iron or com positions of variouskinds.

yI claim as my invention: y

1. -A tem orary plug. for core drills for insertion in t e core receivin opening of the drill comprising plug mem rs mounted in the core receiving opening and a lplug' collapsing member mounted on said s u members andextending ahead of said r' 2. A temploraryplug for core drills for insertion in t e core receivin opening of the drill comprising a collapsi "le li'lilug in the core recei'vn opening frictiona y engaging the inner wa s thereof and means exten 'ng ahead of the drill for collapsing the plug. zo, 3. A temploiary plug for core for in'- serti'on in t e core receiving opening of the drill comprising semicircular plug members y in the core receiving o ening and a member extending between sai plug members in tapered engagement therewith,having its lower end extended ahead of said drill.v 4. A temporary plug for core-drills for insertion in the core receiving opening of the v drill comprising semicircular plug members in the core receiving o ening and a, member extending between sai plug members in tapered threaded engagement therewith have ing its lowerend extended ahead of said drill.

5 A temtlorary plug for coredrills for iny sertion in e core receiving oFening of the vdrill comprising a collapsible p ug member in 'y said core receiving opening and a'dart member arranged to collapse said lug member, said dart -member bein moun on said plug 40 and extending there qw. v

In testimony whereof, I have hereunto set` my hand at Bakersfield, California, this 14th day of September-1928.

ARMEL F. MCQUISTON. t

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