US3731753A

US3731753A - Reverse circulating foundation underreamer

Info

Publication number: US3731753A
Application number: US00158943A
Authority: US
Inventors: A Weber
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-07-01
Filing date: 1971-07-01
Publication date: 1973-05-08
Anticipated expiration: 1990-05-08

Abstract

An underreamer mounted on a Kelly for adjustment and rotational driving thereby. A cylindrical housing surrounds the Kelly and mounts a pair of underreamer blades for an outward swinging thereof. A circulating flow is set up through the apparatus for continually removing the debris as it is cut by the reamer blades.

Description

United States Patent v 1 11 3,731,753 Weber 1451 May 8, 1973 REVERSE CIRCULATING R2l,241 10 1939 Bertran et al ..l75/285 FOUNDATION UNDERREAMER 1,731,732 10/1929 Terrell 1 ..175/2s5 1,737,960 12/1929 Cramer.... ..l75/285 [76] Inventor 5 :22:; BOX 35564 2,450,223 9/1948 Barbour ..l75/285 [22] Filed: Jul 1, 1971 Primary Examiner-James A. Lep ink y P pp No 158 943 Attorney-Clarence A. OBricn & Harvey B. Jacobson y 57 ABSTRACT An'underreamer mounted on 3 Kelly for adjustment Fieid 285 258 and rotational driving thereby. A cylindrical housing surrounds the Kelly and mounts a pair of underreamer [56] References Cited blades for an outward swinging thereof. A circulating flow is set up through the apparatus for continually UNITED STATES PATENTS removing the debris as it is cut by the reamer blades. 2,650,072 8/1953 Kammerer ..175/285 9 Claims, 9 Drawing Figures l F l 64 i? 54 I r 1 l l Q 4 46 v ll} 42 l I I l 1 1 ti. l a i t: 1 r; 60 1 s 1 I l/ l l 44 /4 Q -/6 3 Sheets-Sheet :3

Fig. 7 f

, /6 Fig. 9

/55 I 4/0700 4. Weber- WWW REVERSE CIRCULATING FOUNDATION UNDERREAMER The present invention is generally concerned with the formation of foundation holes, and moreparticularly relates to an underreamer which is utilized in forming an enlarged or bellbottom within a foundation hole.

It is a primary object of the instant invention to provide an underreamer for foundation holes which is constructed so as to enable a continuing upward flow of the debris as it is cut by the blades thereby avoiding the necessity of periodically withdrawing the reamer from the hole.

Another important object of the instant invention is to provide a reamer, mounted on and operable from a standard oil field swivel, which incorporates underreaming blades automatically adjustable so as to efiect the desired undercutting or belling of the bottom of a foundation hole.

Other objects of the instant invention include the provision of apparatus which is of a relatively simple although highly unique construction, durable, easily operated and manipulated, and highly efficient in the performance of its intended function.

Basically, the objects of the invention are achieved through the provision of an elongated cylindrical housing having substantially full length opposed side openings. The housing pivotally mounts a pair of elongated depending reamer blades which selectively ex tend outwardly through the openings. The movement of the blades is controlled by a vertically sliding Kelly movable centrally through the housing and interconnected with the blades by arms whereby a downward movement of the Kelly effects an outward swinging of the blades. The Kelly is in turn telescopically received over a tubular pipe section which, in conjunction with two lower end branches, defines the reverse flow path for the debris and drilling mud.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a side elevational view of the apparatus being introduced in a foundation hole;

FIG. 2 is an enlarged cross-sectional view taken sub stantially on the plane passing along line 2-2 in FIG. 1;

FIG. 3 is a cross-sectional view taken substantially on a plane passing along line 33 in FIG. 2;

FIG. 4 is a top plan view of the apparatus with portions thereof broken away for purposes ofillustration;

FIG. 5 is a cross-sectional view taken substantially on a plane passing along line 5-5 in FIG. 3;

FIG. 6 is a cross-sectional view taken substantially on a plane passing along line 6-6 in FIG. 3;

FIG. 7 is an elevational view of the apparatus with the reamer blades extended to illustrate the nature of the operation performed thereby;

FIG. 8 is an enlarged cross-sectional detail of a reamer blade taken substantially on a plane passing along line 88 in FIG. 2; and

FIG. 9 is a schematic illustration of the mounting of the apparatus.

Referring now more specifically to the drawings, reference numeral 10 designates an elongated cylindrical housing which mounts and encloses the various operating components of the underreamer.

The housing 10 includes two opposed substantially full height openings 12 therein orientated in diametrically opposed relation to each other. The bottom of the housing is closed by a flat base 14 rigid therewith with the flat base inturn rotatably mounting a bottom plate 16 through a central pivot forming pin 18 and a series of peripherally arranged ball bearings 20. The bottom plate 16 is significant in that this plate 16 will remain stationary at the bottom of a foundation hole while the underreaming apparatus rotates thereabove in forming the desired enlarged hole section, thereby avoiding any deepeningor eroding of the bottom of the hole during the underreaming operation.

The upper peripheral edge portion 22 of the cylindrical housing 10 is slightly inward formed and overlies a double walled top closure 24 for the housing 10. The top closure 24 has a pair of diametrically opposed ports 26 defined therethrough, these ports directly communicating with vertical internal channels 28 provided along a major portion of the height of the housing 10,

terminating in spaced relation above the base plate 14. The channels 28 and associated ports 26 are located at right angles to the vertical housing openings 12 and are specifically provided for the introduction of drilling mud utilized in continuously extracting the dug debris during the underreaming operation as shall be explained subsequently. Each of the channels 28 includes a relatively large discharge slot 30 at the lower end thereof, as well as a series of smaller discharge ports 32 for a portion of the height thereof above the bottom slot 30.

The double walled closure 24 at the top of the housing 10 alsoincludes a rectangular opening centrally therethrough which slidably receives an elongated rectangular tube or Kelly 34. The Kelly 34 is guided throughout its range of vertical movement relative to the housing 10 by four rollers 36 which rotatably bear against the sides thereof. Each of the rollers 36 is mounted for free rolling movement between a pair of corner blocks 38, note FIG. 4 in particular for this construction and arrangement. An appropriate stabilizing plate 40 will also be provided within the upper portion of the housing 10 about the Kelly 34.

Positioned centrally within the cylindrical housing 10, and slidably receiving the Kelly 34 thereover, is a vertically elongated rectangular discharge tube or pipe 42, the lower end of which directly communicates with a pair of opposed diverging and downwardly directed branch sections 44 which in turn terminate in large mouths orientated slightly above the base plate 14 for reception of the drilling mud and carried debris to the pipe 42 and Kelly 34. The discharge pipe 42 and the lower branches44 thereon are stabilized within the housing by a pair of bracing plates 46 welded to the housing and the branch sections 44. If so desired, the lower portions of the branch sections 44, which lie against opposed portions of the housing wall, can also be directly welded thereto.

The actual reaming or underreaming operation, which results in a belling enlarging of the bottom of a .foundation hole as illustrated in FIG. 7, is effected by a pair of opposed vertically elongated blades 48. The two blades 48 are orientated in opposed relation to each other in alignment with the opposed housing openings 12 for selective extension therethrough. Each blade is mounted by an elongated hinge or pivot pin 50 which extends through the upper end thereof and has the opposed ends fixed to the housing or appropriate mounting blocks 50 provided therein. A series of cutting teeth 52, preferably replaceable, are provided along the full length of the leading edge of each blade 48. The trailing edge of each blade 48 tapers inwardly along the length of the blade so as to provide a relatively narrow lower end on each blade. Noting FIGS. 2 and 7 in particular, it will be appreciated that the major portion of each blade 48 is straight with the bottom section thereof angled slightly inward, thereby enabling a bell shaping of the hole. FIG. 8 illustrates the preferred tapered cross-section of the blades 48.

The lateral swinging or adjustment of the two blades 48 is effected by a vertical adjustment of the Kelly 34 relative to the housing 10 utilizing a pair of actuating arms 54. Each arm 54 has a first end thereof hinged to one of the blades at the upper end of the lower section designated by the reference numeral 56. The second end of each arm 54 is orientated slightly beyond the Kelly 34 and pivotally affixed within a mount 58 which is inturn rigidly affixed to the Kelly 34. In this manner, it will be appreciated that the two actuating arms 54 cross each other at the Kelly 34 whereby a maximum inward swinging or collapsing of the blades 48 can be effected upon the upward movement of the Kelly 34 relative to the housing 10. As a safety feature, a pair of cables 60 are engaged between each blade 48 and the adjoining end portion of the corresponding arm 54. Likewise, a similar pair of cables 62 will be provided between the Kelly 34 and the inner end portions of the arms 54.

The top of the Kelly 34 is provided with an outwardly projecting flange 64 thereabout which is used to connect the Kelly to one or more tubular extensions with the entire unit being operated basically in the manner of conventional drilling equipment, utilizing a standard oilfield swivel 68.

In operation, as the apparatus is being lowered into a foundation hole, the housing 10 will be at its lowermost position on the Kelly 34 with the blades 48 swung inwardly to their innermost position and the housing supported from the Kelly 34 through the Kelly engaged pivotally mounted actuating arms 54. When the bottom of the hole is reached, a continued downward movement of the Kelly against the now stationary housing 10 will result in outward swinging of the blades 48. As the blades are swung outward, the apparatus is rotated to form the underreaming desired. As will be appreciated, the rate at which the blades 48 are extended will vary depending upon the resistance encountered. The rotation is effected through a conventional rotatable driving of the Kelly 34 with this rotation being transmitted to the housing 10 by the torque accommodating Kelly engaging rollers 36. As the rotational reaming is being effected, it will be appreciated that no deepening or eroding of the bottom of the hole will be effected due to the bottom plate 16 remaining stationary as the housing rotates thereabove. Upon a completion of the underreaming operation, the entire apparatus can be easily withdrawn with the initial upward movement of the Kelly 34 first effecting an inward collapsing of the blades into the housing 10 through the vertical side openings 12 provided therein and a subsequent elevating of the housing and blades.

Specific provision is also made for effecting a continuation discharge of the cut debris. This is effected by utilizing pressure introduced drilling mud which flows through the ports 26, along the channels 28 and out the

openings

30 and 32 during the actual underreaming operation. THe mud mixes with the cuttings being removed from the bottom of the holes and is reintroduced through the bottoms of the two branch sections 44 for an upward flowing through the pipe 38, Kelly 34 and Kelly extension 66 for discharge through an appropriate ejection line 70. This continuous extracting of the debris is aided by an air induction system whereby air, through an appropriate air line 72, is induced into the Kelly at a point approximately twothirds of the distance from the top of the hole in a manner so as to cause a vacuum which effects an upward sucking of the mud and cuttings and a reverse circulation of the debris outward of the hole.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. An underreamer for foundation holes and the like and comprising a vertically elongated hollow housing, said housing including a plurality of longitudinally extending openings therein, a plurality of blades, means pivotally mounting said blades within the upper portion of said housing, said blades extending vertically within said housing in alignment with said openings for selective movement between a first position retracted within said housing and a second position swung outwardly thereof through said openings, an elongated hollow Kelly vertically slidable centrally within said housing, said Kelly projecting vertically above said housing, actuating means interconnecting said Kelly and said blades whereby downward movement of said Kelly relative to said housing will effect an outward swinging of said blades and upward movement of said Kelly relative to said housing will effect a corresponding inward swinging movement of said blades, and a vertical discharge pipe located centrally within said housing and telescopically receiving the Kelly thereover, said discharge pipe having an open lower end and a hollow interior communicating directly with the interior of the hollow Kelly for an upward movement of debris therethrough.

2. The underreamer of claim 1 wherein each blade is straight for a major portion of the length thereof downward from the means pivotally mounting the blade within the upper portion of the housing, each blade including a bottom section angled inwardly.

3. The underreamer of claim 1 wherein the actuating means interconnecting the Kelly and the blades comprises a plurality of arms, each arm interconnecting the Kelly and one of the blades, said arms being pivotally connected at a first end thereof to said Kelly and at a second end thereof to the corresponding blade, said actuating arms beings, in each instance, pivoted at a point slightly beyond the Kelly through a mounting unit rigidly affixed to the Kelly, thereby providing for a tight inward swinging of the blades upon an upward movement of the Kelly relative to the housing.

4. The underreamer of claim 1 wherein said housing includes a plurality of open ports through the upper end of said housing, said open ports communicating directly with longitudinally extending channels within said housing for the introduction and downward movement of drilling mud therethrough, and discharge means toward the lower ends of said channels for a discharge of drilling mud from the channels at the underreaming site.

5. The underreamer of claim 4 including a bottom plate rotatably fixed to the lower end of said housing defining a stationary base for support of the housing and blades during the rotation thereof.

6. The underreamer of claim 5 wherein said Kelly is rectangular in cross-section, the upper end of said housing mounting four rollers engaged with the Kelly peripherally thereabout, the rotation of said Kelly providing a rotating force to said housing through said rollers.

7. The underreamer of claim 4 wherein the lower portion of said vertical discharge pipe is provided with downwardly and outwardly divergent branch sections terminating in open ends adjacent the lower end of said housing.

8. The underreamer of claim 7 wherein the discharge means in the drilling mud channels comprises a series of vertically spaced openings communicating with the exterior of said housing.

9. An underreamer for foundation holes and the like comprising a vertically elongated housing, a plurality of blades, means pivotally mounting said blades within the upper portion of said housing, said blades extending vertically for selective movement between a first position retracted within said housing and a second position swung outwardly thereof, an elongated hollow Kelly vertically slidable centrally within said housing, said Kelly projecting vertically above said housing, actuating means interconnecting said Kelly and said blades whereby downward movement of the Kelly relative to the housing will effect an outward swinging of said blades and an upward movement of said Kelly relative to said housing will effect a corresponding inward swinging movement of said blades, and a vertical discharge pipe located centrally within said housing and telescopically receiving the Kelly thereover, said discharge pipe having an open lower end and a hollow interior communicating directly with the interior of the hollow Kelly for an upward movement of debris therethrough, and channel means vertically through said housing for the downward movement of drilling mud therethrough and discharge means toward the lower end of said channel means for discharge of drilling mud from the channel means at the underreaming site.