US2546950A - Tubing anchor - Google Patents

Description

J. D. NIXON TUBING ANCHOR March 27, 1951 2 Sheets-Sheet 1 Filed April 22, 1949 Jeda'y Q Nixon INVENTOR J. D. NIXON TUBING ANCHOR March 27, 1951 2 Sheets-Sheet 2 Filed April 22, 1949 Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE 6 Claims.

as well as making for less expensive manufacture by reducing the amount of machining and finishing required.

Another object of the invention is to provide an improved anchor having a cylindrical body formed with elongate bosses and valleys between said bosses, whereby the slips may be formed with inwardly directed wings extending into thevalleys and holding the slips against circumferential creeping and more particularly, each wing giving sufflcient bulk or cross-sectional area to provide axial cores which are not reached when the slip is heat treated; such cores providing tough centers and enhancin the tensile strength and toughness of the slip.

' A construction designed to carry out the invention will be hereinafter described together with 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, 'wherein examples of the invention are shown, and wherein:

Fig. 1 is a view'partly in elevation and partly in section of a tubing anchor constructed in accordance with the invention,

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

Fig. 3 is a vertical sectional view through one -of the slips,

Fig. 4 is an inner elevation of one of the slips,

Fig. 5 is a horizontal cross-sectional view taken on the line 5-5 of Fig. 4,

Fig. 6 is a plan view of one of the slips, and

Fig. 7 is a partial vertical sectional view of a modified form of the invention.

In the drawings the numeral l0 designates a tubular insert or mandrel which ha a screwthreaded pin I l at its lower end and an internally screw threaded box 12 at its upper end, whereby it may be connected in a string of well tubing in the usual manner. At the medial portion of the mandrel a cylindrical enlargement or body I3 is formed integral therewith and connected at each end with the pin and box by annular shanks-0r necks I4;

2 At the top and bottom the body has annular, beveled seats [5 inclined toward the necks. At

the upper end of the pin an annular colla [6 is made integral with the lower neck l4. At the bottom of the box l2 an annular shoulder 11 is provided. The distance between the upper seat I5 and the shoulder I! is substantially the same as the distance from the bottom seat to the collar 16. The necks with the collar and shoulder C011? stitute annular grooves l8.

Quadrilateral, segmental slips or jaws I9 surround the body 53 and are of particular construe: tion. A description of one of the slips will suifice for all of them. It will be observed that the body I3 is formed with four equally spaced vertical bosses 20 having vertical valleys or recesses 2T therebetween. The outer faces 22 of the bosses are curved transversely, preferably concentric to the outer faces of the slips.

Each slip I9 is formed with a transversely curved inner top and bottom surfaces 23, substantially concentric to the necks M and with a vertical pocket or sump 24 receiving one of the bosses 29. The bottom 25 of the sump or inner face of the slip is struck on an are complementary to the face 22 of the boss so as to intimately engage said face, whereby an inward transverse thrust sustained by the slip is absorbed by the boss and distributed over the broad area of said boss.

The sump 24 is flared outwardly from its face 25 to conform to the seats l5 and the sides of the boss. However, the sump is considerably larger so that when the faces 22 and 25 are in contact, no other portions of the'slip are intentionally in contact with any part of the body, except that the slip may shift vertically and seat on one'of the seats IE or it may shift circumferentially and'contact one side of the boss 22. The inner surfaces 23 of the slip do not engage the necks l4. Thisconstruction provide for a free radial movement of the slip and as before stated, imparts its entire inward thrust to the face 22 of the ss.-

The slip is formed with outer horizontal curvilinear teeth 26, as in-rny former Patent 1,941,813, these teeth are V-shaped in cross-section and because of their close spacing, as well as their shape, may be referred to as level threads. The teeth of the slip are disposed in such a transverse are that when all of the slips are fully expanded, they will be in" an annulus substantially concentric to the casing or pipe, in which the anchor is located, so as to bite uniformly into the inner wall of said casing or pipe;

As is best shown in Figs. 2, 4 and 5, the slip vertical wings 2-1, the inner edges of which-are oifset outwardly from the top and bottom surfaces 23 and extend into the valleys 2|. Each wing is flared outwardly or wedge-shaped in cross-section. It is preferable to drop forge the slip and to heat treat it to the required hardness. Since heat treating penetrates the surface of the metal, it will be seen that because of the transverse or cross-sectional area of each wing,

sufficient body or bulk is provided, whereby a core or axial area is provided in the center of the wings 2'! in providing a core in connection with the heat treating of the slip.

the wing which is not hardened and this tough center enhances the tensile strength of the slip.

The Wings 21 not only increase the strength of the slip, but permits the outer surface of the slip to be turned down to fit a smaller diameter casing or pipe and the entire tooth surface to be heat treated. The wings also hold the slip against undesired circumferential movement. By drop-forging the slip and its loose mounting on the boss 20, the only machining required is that of the teeth,

Each sliphas reduced integral segments 28 at its top and bottom above and below its teeth.

bore being spaced above the other bore and each bore having an annular stop shoulder or abutment 33 at its inner end surrounding an as an O-ring. It is obvious that when the inner .endsof the pistons'are subjected to fluid :pressure, sufific'ient to overcome the spring rings 39, said pistons will be forced outwardly, thereby displacing the Slips l9 outwardly. 'When the fluid pressure is sufiiciently reduced. the rings 30 will retract the slips and the pistons.

Anchors of this type are particularly adapted for use with reciprocating well pumps and be' cause of the V-shaped teeth, will hold the tubing and working barrel against both upward and downward movement or creeping. The-anchor of course has many uses. By being able to turn down the slips I9 to reduced diameters, the number of sizes in which the anchor must be made is; reduced. The provisions of the wings,

whereby the web of. thebslip between said wings may be reduced in thickness, due to turning the face down to a reduced diameter without seriously weakening the slip, isquite angadvantage. I

\ ..In the prior patents hereinbefore referred to,

the slips were comparatively thin and of uniform thickness. .When such slips were heat treated they had a tendency to become brittle and did not lend themselves to machining to .reduce their diameters. By employing the wings the slips may be made thicker and the circumv fe rential area which-contacts the bossesis less The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materialaas well as in the details of the illustrated construction may be made,

within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. A tubing anchor including, artubular mandrel adapted to be connected in a well tubing and having a body intermediate its endsprovided with elongated bosses and valleys there- "oetween, radially movable slips on said bosses having thickened Wings disposed in the valleys, piston means mounted in the bosses of the body exposed to the bore of the mandrel and engaging theslips, and retaining means holdingthe slips in assembled relation to the body.

. 2.-A tubing anchor as set forth in claim 1, wherein'the bosses and the slips havecurvilinear contacting areas surrounding the piston mean betweenthe valleys and wings.

3. A tubing anchor as set forth in claim 1, wherein the wings are wedge-shaped and each wing provides an axial unhardened core when the. slip is heat treated.

4. A tubing anchor including, a tubular man drel hELVll'lglYlBEtllS atseach endv for-connecting it in a string of well tubingan elongate body intermediate the ends of. the mandrel having elongate bosses and elongate valleys betweensaid bosses, each boss having spacedcylindrical bores extendin radially therein and open to the bore of the mandrel, elongate cylindrical pistons fitting in the bores of the bosses and. surrounded by packing-rings, elongate slips having sumps receiving the bosses and the pistons, elongate wings on the slip on each side of the sumps extending into the valleys, and spring-rings surrounding the slips and holding them on the bosses" 5. A tubing anchor as set forth in claim '4, wherein the outer faces of the bosses and bot,- toms of the slip sumps are concentric andin contact and said sumps, are larger than the bosses to provide freedom of movement of said slips.

6. A tubing anchor as set forth. in claim 1, wherein each boss has a circumferential groove and each slip has a transverse arcuate rib engaging in said groove. g

JEDDY D. NIXON.

7 REFERENCES CITED The following references are of record in'. the file of this patent:

ST TES :eA'rErrrsv 1 UNITED 7,

Number Name a Date. .7 1,056,430 Wood Mar. 18,1913 1,713,150 Smith Ma 14. 1929 1,912,805 Tilbury June 6,1933 1,941,813 I Nixon et a1. .Jan. 2, 1934 1,972,408 Nixon Sept.,4, 1934 2,009,164 --Golmerauer July 23,1935

Gardner 4--.; July- .9; 1941

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