US1780447A

US1780447A - Rotary core drill

Info

Publication number: US1780447A
Application number: US230500A
Authority: US
Inventors: Shows John Elgin; Dunn William Tracy
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-11-02
Filing date: 1927-11-02
Publication date: 1930-11-04
Anticipated expiration: 1947-11-04

Description

Nov. 4, 1930.

mmvronsj ufghrgflfimasf ATTORNEY.

m. 1 m f ROTARY CORE DRILL Filed Nov. 2, 1927 J. E. EHGNS ET AL Patented Nov. 4 1930 UNITED STA S PATENT OFFICE .form nmnr snows, ornanmsnune, AND WILLIAM may norm, or noulsron,

'rnx'as ROTARY conn DRILL This invention relates generally-to drills 1 particular reference to rotary core drills The primary object of the invention 15 to 6 provide a drilling tool having a head of extremely simple. construction but of durable character, which may effectively be used n earth boring operations wherein strata of various characters may be encountered with little likelihood of damage or destruction to the head or any of the parts thereof.

A further object is to provide a drill head of this character which has its parts so assembled as to permit of repairs being quickly special skill or tools, and which repairs or adjustments may be made at the scene of operations and without resorting to forwarding the head to a machine shop for such corrections.

A further object is to provide in a drill head of the character generally specified, improved means for operating upon and gripin a core as the latter passes through the flea whereby to insure holding of the core against movement when the drill is moved from the well.

A still further object resides in the specific construction, assemblage and mode of operation of the core gripping member whereby to insure proper removal of the core at any desired time.

With these objects in View, together with others which will appear as the description proceeds, the invention consists in the novel construction, combination and arrangement of parts, all as will be described more fully hereinafter, illustrated in the drawings, and particularly pointed out in the claim.

In the drawings:

Fig. 1 is a view taken longitudinally through a core drill head embodying the invention,

Fig. 2 is an enlarged view taken substanand easily made without the exercise of.

Application. filed November 2, i927. Serial No. 230,500.

tially upon line 2-2 of Fig. l and looking in the direction indicated by the arrows,

Fig. 3 is a fragmentary view taken substantially upon line 33 of Fig. 2, and

Fig. 4 is a side elevation on a reduced scale, taken at right angles to Fig. 1, illustrating the lower end of the head.

The drill head is represented generally at 4, and comprises an elongated metallic member of proper length and diameter, having its upper end reduced and threaded as shown to permit of screw threaded attachment to the drill stem 5. The head is provided'with a central longitudinal opening 6 extending from the inner toward the outer end of the head, and this opening is reduced in diam- .eter near its outer end to provide a shoulder 7 the reduced portion of the bore or opening constituting a coreway indicated at 8. This coreway, like the opening 6, is of circular formation. The opening 6 at the inner end of the head is internally threaded to receive the external threads of a barrel 9, the latter having an internal diameter or coreway corresponding to the dimension of the coreway 8. When properly inserted in the opening 6, the coreway of the barrel will be axially aligned with the coreway 8. The-outer end of the barrel terminates short of the shoulder 7, so that a space is provided between said shoulder and the adjacent terminal of the barrel.

Within thespace thus provided a gripper member for the core is arranged. This member is of such construction and operates in such manner with the drilling process as to permit of free feeding of the core-without obstruction or interruption, yet operates in such manner that upon withdrawal of the head the core is bitten or broken and held against dropping out upon removal of the tool; In obtaining these results, we employ a core gripper capable of freely rotating within the head and having limited longitudinal movement. The member employed com- 90 prises an annular member,- ring or column indicated at 10, of slightly smaller external diameter than the internal diameter of the opening 6, and having an internal diameter corresponding to the diameter of the coreway 8. This annular member is provided at proper intervals around its periphery with rollers or anti-friction members 11 which engage the inner wall in the opening 6. The height or thickness of the collar 10 is slightly less than the distance between the shoulder 7 and the adjacent end of the barrel 9. The distance between these elements may be varied as desired to increase or diminish the degrees of longitudinal travel of the collar 10. In the present instance, but little play is permitted the collar l0,'as the distance between the end of the barrel-and the shoulder 7 is relatively short.

The collar or annulus carries a plurality of grippers capable of engaging and firmly holding the core as it passes through the column. These grippers in the present instance comprise pawls or dogs 12 pivoted at their inner ends as at 13 within the collar and extending normally into the coreway within the collar. These dogs are set in recesses .14 in the inner face of the collar, and these recesses are so shaped as to permit the free ends of the dogs to swing away from the axis of the collar in an u ward direction. Each dog has a toe 15 at its inner extremity to seat against a shoulder in the collar to limit the inward swinging movement of the dogs.

There may be an desired numbr of pawls or dogs 12 carried y the collar, and it is preferred that they be disposed radially of the annular member 10.

The head 4 is provided near its lower end with bottom and side cutters for operation properly upon earth or rock in drilling the hole. The lowermost of these cutters 16 are of preferably frusto conical formation and are mounted in the end of the head at an angle to the axis thereof. These cutters have their inner edges disposed substantially in alignment with the outer edges of the coreway, so that in rotary cutting operations a smooth core will be formed to pass into the coreway. Disposed at substantially right angles to the cutter 16 and elevated slightly therefrom so as to protrude beyond the sides of the head are cutters 16'. These cutters 16-16 facilitate penetration as rotary movement is applied to the head and clears the way as downward progression is made. Each cutter is referably supported upon a bearing bolt 17 t readed at its innerextremity into the head so as to be capable of being easily removed when required, and washers 18 are used in the assembly to minimize friction and to prevent jamming of the cutters. In the sides of the head at a point substantially re mote from the lower end thereof clearance cutters 19 are mounted in a manner similar to the cutters 16--16v and for purposes well understood. The head is equipped with ducts 21 leading from the upper end of the head to the cutters at the lower end thereof, and branch ducts 22 communicate with the recesse's in which cutters 19 are mounted. These ducts permit of proper lubrication of the rotating cutters, as will be readily understood.

In operation, the head is given rotary drilling movement, and the

cutters

16 and 16 penetrate the earth and clear the way forthe head. The core passes upwardly through the coreway 8, and upon engagement with the dogs 12 forces them outwardly so as to pass into the coreway of the-barrel 9. Free passageof the core through the collar is permitted by reason of the restricting movement of the dogs as well as the mobility of the collar both longitudinally and rotatably. This movement of the collar permits of the free passage of the core with the least possible danger of breakage of the same. When it is desired to remove the drill, upward movement applied to the drill stem will cause the head to move similarly, whereupon the action of the pawls in grippinig engagement with the core causesthe free ends of the pawls to bite into the core and sever the same at their point of engagement therewith. The downward movement to a slight degree permitted in the collar facilitates this cutting-elf operation. The core may then be removed from the barrel in the usual manner.

By constructing the head and its assembled parts in this manner, it is apparent that the head is considerably strengthened and will therefore withstand excess pressures with a minimum of opportunity forbreakage or derangement of any of the parts. The drilling operation may be conducted more rapidly than has heretofore been possible, and the construction obviates the necessity of aspirators or check valves in the core barrel. The assemblage is such that in case of wear of the parts they may be easily replaced without the exercise of-special skill or tools, and replacement of broken or worn cutters may be made, if desired, without detaching the head from the drill stem.

While the foregoing is a description of the Having thus described our invention, we

claim:

In a cutter, a head having a coreway therein, a collar slidable loiigitudinally'therein, the said collar having longitudinally dising relatively deep at their lower ends, a dog pivoted at its lower end in the deeper portion of each of said recesses, the bottom walls of said recesses inclining in an upward .125 ppsed recesses in its inner face, said recesses direction toward the axis of said collar to receive said dogs for a substantial part of their length and to maintain the same inclined toward the axis of said collar, said dogs of slightly greater length than their recesses so that their free ends project beyond the upper end of said collar, and a toe on each dog to engage with its respective bottom wall to limit the inward swinging movement of the dog.

In testimony whereof we hereby afiix our signatures.

JOHN ELGIN SHOWS. WILLIAM TRACY DUNN.