US2176355A - Drumng head - Google Patents

Description

H. c OTIS DRIYLLING HEAD Oct. 17, 1939.

Filed Sept. 2, 1937 2 Sheets-Shem- 1 Oct. 17, 1939. c QTIS 2,176,355

DRILLING HEAD Filed Sept. 2, 1937 2 Sheets-Sheet 2 Herbem 1C. Oi is Gummy Patented Oct. 17,1939

UNITED STATES PATENT OFFICE Hcrbfrt 0. :l asiTex. Application September 2, 1931, Serial N6. 162,184

10 Claims.- (01. 255-1) This invention relates to new and useful improvements in drilling heads.

One object of the invention is to provide an improved drilling head which is particularly 6 adapted for use in packing of! around a drill stem of a well, or other progressive element, and which will effectively hold its seal under various conditions, whereby various well operations, such as drilling under pressure, may be performed. 10 An important object of the invention is to provide an improved drilling headhaving an elastic packing member through which the rotatable drill stem or keliy extends, together with pressure means for distorting said member into packing position around the stem or kelly; the head being so constructedthat'it may undergo a lim ited swinging or tilting movement without [breaking its packing seal with thestem, whereby the heah is self-alining to compensate for irregularities in the stem or kelly, misalinemnt of the well connections with the drive member through which the stem or kelly extends, or lateral move-- ment of said drive member.

-. A further object of the invention is to provide 5 an improved drilling head of the character described, having pressure means for distorting the packing. member, and being so constructed that the pressure fluid may be utilized to lubricate the bearing members of the head, said means 30 also being so constructed that it does not interfere in any way with the swinging or tilting of the head.

Still another object of the invention is to provide an' improved drilling head'includin'g an outer.

35 member having an inner member rotatable therein, with improved bearing elements between the members so as to permit the inner member to undergo lateral movement, as well as to swing or tilt within the outer member; said inner mem- 40 her having a deformable packing therein for engaging the drill stem or kelly to pack ofi therearound and being arranged to be deformed into packingposition by fluid pressure.

A construction designed to carry out the in- Q 45 vention will be hereinafter described, togetherwith other features of the invention,

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and

wherein: g

Figure l is a view, partly in elevation and partly in section, of a head, constructed n accordance with the invention,

Figure 2 is a horizontal, cross-sectional view, taken on the line 2--2 of Figure 1,

Figure 3 is a view similar to Figure 2 with the packing elementin its distorted position,

Figure 4 is a view, similar to Figure l of a 5 modifled formof the invention, and

1 Figure 5 is a reduced view, partly in elevation and partly in section, of a modified form of the upper portion of the drilling head.

In the drawings, the numeral I designates a cylindrical casing or shell which has its lower end bevelled'at ll, whereby the shell may be mounted withima suitable'housing or support i2. The housing is provided with an internal annular seat I! on which the bevelled lower end of the shell is supported. A suitable retractible latch member I! which is mounted in the upper end of the housing I2, is adapted to overlie an external shoulder l5 which is formed near the lower end of the shell i0. Manifestly, the latch member H serves to prevent upward displacement of the shell from the housing i2, and it is pointed out that said latch forms no part of the present invention, being described merely for the sake of clarity. The shell has a vertical bore 16 which has its lower end reduced in diameter at IT, and between said bore and this reduced portion, an internal annular flange I8 is formed.

A second inwardly directed annular flange i9 is located at substantially mid height of the reduced portion ll of the bore, while an internal annular shoulder 20 is provided at the extreme lower end of said reduced portion.

Rotatably mounted within-the shell l0 isan elongated cylindrical body 2| which has, sub- 85 stantially the samelen'gth as the shell. The diameter of the body is less than the inner diameter of the internal flanges l8 and i9, whereby the body may move a limited distance laterally within the shell. An upwardly directed annular flange 22 is spaced from the bore 23 of the body 2i and is located near the lower end of said bore. The flange 22 is preferably made integral with the body 2 i and manifestly the disposition of said flange forms anannular recess 24 within the bore of the .body. This recess is adapted to receive the lower reduced end of a packing sleeve or element 25. The packing element normally has its outer surface engaging the wall of the bore 23. The upper end of said packing element is reduced and this reduced portion is engaged by a flanged ring or collar 26 which is inserted within the bore of the body 2!. =A-packing gland nut 21 is screw-threaded into' the. upper end of the body 21 and has its lower end'engaging the 5;,

top of the ring or collar 26 to hold the same within the body. w a

If desired, a suitable packing ring 28 may be interposed between the ring or collar 26 and the wall of the bore 23, as is clearly shown in Figure 1, to prevent leakage upwardly therebetween, However, it may be preferable to omit the packing ring 28, and to provide annular sealing lips on the outer surface of the packing element 25. The lips are located near the upper and lower ends of the element and are so disposed that a pressure fluid, within the bore 23 of the body and between the wall of sald'bore and the packing element 25, will be trapped between said. lips and will act to hold said lips in sealing engagement with the wall of the bore 23, whereby leakage in either an upward or downward direction will be prevented.

From the above, it will be seen that the packing element 25 which is preferably constructed of rubber, rubber compound, or other elastic material, is confined within the bore of the body 2| between the recess 24 and the retaining ring or collar 26. By removing the-gland nut 21 from the upper end of the body 2|, the collar or ring 26 and the packing element 25 may be readily removed from the bore and a new packing element may be inserted within said bore. As is clearly shown in Figure 2, the elastic packing element or sleeve 25 is provided with a plurality of vertical grooves or recesses 29, which recesses are formed in the inner face of said element. The recesses terminate short" of the upper and lower ends of the packing element, extending only throughout the central portion of said element. Similar grooves or recesses 30 are formed in the outer face of the'packing element and these latter grooves are staggered with relation to the grooves 29.- It will beevident that the grooves 30 are located adjacent the wall of the bore 23 of the body, while the, grooves 29 are located adjacent the exterior surface of the drill stem which extends through the device. The provision of the vertical grooves in the packing element perrm ts said element to be deformed to the position shown in Figure 3, which reduces the diameter of the element, while maintaining a smooth inner surface for engagement with the drill stem or kelly.

For rotatably supporting the body 2| within the shell In, said body is formed with an external annular flange 3| which is located substantially at the mid-height thereof. The flange extends into the bore of the shell and is of such .:width that when the body is disposed axially within said shell, there is a clearance or space 32 between the outer edge of the flange and, the

wall of the bore l6. As clearly shown in Figure l, the flange 3| overhangs the internal flange l8 within the shell, which latter flange is provided with an annular recess or groove 33 in itsupper face. This groove receives an elastic supporting ring 34 which has its upper end projecting from the groove. A metallic antifriction ring35, preferably of bronze, is supported on the elastic ring and surrounds the body 2|. It is noted that the outer edge of the ring is contiguous to the wall of the bore ||i of the shell, there being a slight clearance therebetween, while there is a comparatively large clearance between the inner edge of said ring and the The external flange 3| on the body -rests on the antifriction ring 35 whereby the body is suspended from the flange and due to the clearance between the flange and the bore It as well as new the clearance between the inner edge of the ring 35 and the body 2|, said body may move a limited lateral distance within the shell. .To permit free rotation of the body within the shell, ball bearings 36 are mounted in annular races 31 which are supported on the flange 3|. The outer edges of the races do not contact the bore I6 of the shell HI, leaving a clearance space which allows the races to move laterally with the body. The upper face of the upper race is arcuate as shown at 38 and is engaged by the arcuate underside ,of i retaining ringor follower 39. The ring 39 is held within the shell by arnut 40 which is screwed into the upper end of the shell I0. As clearly shown in Figure 1, the bore of the nut 40 is recessed at 4| -to receive a plurality of V-shaped packing rings 42 which pack off the space between the nut and the body 2|. The shape of the packing rings 42 is such thata pressure from within the shell l0, that is, a pressure from within the annular space between the shell "I and the body 2| will cause a distortion of the packing rings to force them into close sealing engagement with the exterior surface of the body 2|.

For packing off the space between the reduced portion I! of the bore of the shell l0 and the exterior surface of the body 2|, a plurality of resilient packing rings 43, similar to the rings 42, are supported on the flange l9, which extends inwardly from the" reduced portion of the bore of said shell. These rings are so disposed that a pressure from within the annular space between the body 2| and the shell l0, expands the same into sealing engagement with said shell and body 2|.- To prevent the well pressure from escaping upwardly between the body 2| and the shell I0, a plurality of packing rings 44, which are of an inverted V'-shape, are located between the extreme lower end of the body 2| and the bore of the shell I0. As is clearly shown in Figure 1, the rings 44 are positioned directly beneath the flange H).

In operation, the drill stem or kelly A extends through the device, that is, through the body 2|. In the drawings, a kelly is shown and the normal position of the packing element 25 is such that there is a clearance between the bore of said element and the exterior surface of the kelly. In order to obtain a seal between the body 2| and the kelly A, it is necessary that the packing element 25 be moved inwardly into snug engage-- well pressure is, therefore, completely sealed oil (30 and held.

For distorting the packing element 25 so as to move the same into engagement with the exterior surface of the kelly A extending'therethrough, the flange 3| on the body 2| is provided with a plurality of radial ports 45 which extend entirely through the flange andcommunicate with the interior of the body 2|. A pressure fluid line 46 is connected in a radial opening 41 provided in the wall of the shell l0 and serves to supply a pressurefluid to the interior of the shell Ill.

When it is desired to contract or deform the packing element 25 into its sealing position, pressure fluid is introduced through the line 46 into the space between the shell l0 and the body 2|.

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