United States Patent [19]
`Anderson et al. (cid:9)
`
`4,653,953
`[11] Patent Number: (cid:9)
`[45] Date of Patent: Mar. 31, 1987
`
`[54] SUCKER ROD CONSTRUCTION
`[75] Inventors: Roger A. Anderson; James L.
`Goodman; John D. Tickle; A. Keith
`Liskey, all of Bristol, Tenn.
`[73] Assignee: Morrison Molded Fiber Glass
`Company, Bristol, Va.
`[21] Appl. No.: 821,874
`Jan. 24, 1986
`[22] Filed: (cid:9)
`
`Related U.S. Application Data
`[63] Continuation of Ser. No. 532,920, Sep. 16, 1983, aban-
`doned.
`[51] Int. CI? (cid:9)
`[52] U.S. CL (cid:9)
`
` F16B 11/00
` 403/268; 403/265;
`403/41
` 403/268, 267, 266, 265,
`403/368, 41
`
`[58] Field of Search (cid:9)
`
`[56] (cid:9)
`
`References Cited
`U.S. PATENT DOCUMENTS
` 285/114
`2,216,945 10/1920 Hindeliter (cid:9)
` 403/361
`4,315,699 2/1982 Lusk (cid:9)
` 403/267
`4,360,288 11/1982 Rutledge, Jr. et al. (cid:9)
` 403/268
`4,401,396 8/1983 McKay (cid:9)
` 403/268
`4,430,018 2/1984 Fischer (cid:9)
`403/268
`4,475,839 10/1984 Strandberg (cid:9)
` 403/343
`4,484,833 11/1984 Gallagher, Jr. (cid:9)
`FOREIGN PATENT DOCUMENTS
`681550 10/1952 United Kingdom (cid:9)
`403/267
`Primary Examiner—Andrew V. Kundrat
`
`Assistant Examiner—Joseph A. Fischetti
`Attorney, Agent, or Firm—Lalos, Keegan & Kaye
`[57] (cid:9)
`ABSTRACT
`A sucker rod construction including a connector mem-
`ber being formed to define a rod receptacle having a
`closed axially inner end and an open axially outer end.
`The rod receptacle has a plurality of axially spaced,
`tapered annular surfaces. The end of a cylindrical fiber-
`glass rod is received within said rod receptacle through
`the outer end and cooperates therewith to define an
`annular chamber between the outer surface of the end
`of the rod and the tapered annular surfaces. A bonding
`material is positioned in the annular chamber and bonds
`the outer surface of the end of the rod and the tapered
`annular surfaces. Each of the annular surfaces has an
`angle of taper with respect to the outer surface of the
`fiberglass rod, and each angle of taper is progressively
`less toward the open end by at least one and one-half
`degrees. A collet is connected to the connector member
`adjacent the open axially outer end of the rod recepta-
`cle and it has an axial bore therethrough retaining the
`end of the rod in coaxial position within the rod recepta-
`cle. A protective sleeve is disposed between the collet
`and the rod. The collet has an axially extending tubular
`portion having an outside diameter which is smaller
`than the outside diameter of the connector member, and
`a joining portion joins the outside surface of the collet
`and the adjoining outside surface of the connector mem-
`ber. The joining portion has an outer surface with a
`smooth curve extending between the collet and the
`connector member.
`
`28 Claims, 4 Drawing Figures
`
`10
`
`Petitioners' Exhibit 1018
`John Crane v. Finalrod
`IPR2016-01827
`Page 1 of 7
`
`(cid:9)
`

`
`U.S. Patent Mar. 31, 1987 (cid:9)
`
`Sheet 1 of 2 (cid:9)
`
`4,653,953
`
`Page 2 of 7
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`

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`U.S. Patent Mar. 31, 1987 (cid:9)
`
`Sheet 2 of 2 (cid:9)
`
`4,653,953
`
`FIG. 3.
`
`32
`
`FIG 4.
`
`36
`41 38
`
`32 (cid:9)
`
`12
`
`Page 3 of 7
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`

`
`1
`
`SUCKER ROD CONSTRUCTION
`
`4,653,953 (cid:9)
`
`2
`pertains from the foregoing description taken in con-
`junction with the accompanying drawings.
`THE DRAWINGS
`FIG. 1 is a perspective view of a sucker rod construc-
`tion embodying the present invention.
`FIG. 2 is an enlarged cross-sectional view taken
`along line 2-2 of FIG. 1.
`FIG. 3 is an enlarged fragmentary view of the portion
`10 of FIG. 2 illustrated by line 3.
`FIG. 4 is a fragmentary view similar to the lower left
`corner of FIG. 3 illustrating a second embodiment of
`the present invention.
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`Referring to FIGS. 1 and 2, a sucker rod shown gen-
`erally at 10 embodying the present invention is illus-
`trated. Sucker rod 10 generally comprises four basic
`20 members: a connector member shown generally at 12
`formed of a single, continuous piece of steel and having
`a rod receptacle 14 therein; a cylindrical fiberglass rod
`16 which fits in rod receptacle 14; a body of adhesive
`material 18 positioned within rod receptacle 14 and
`25 between fiberglass rod 16 and connector member 12;
`and a plastic, cylindrical sleeve 20 positioned at the
`outer end 22 of connector member 12 and at least par-
`tially positioned between connector member 12 and
`fiberglass rod 16.
`Connector member 12 at its inner end 24 has a cou-
`pling member shown generally at 26. Although shown
`as a male coupling, this coupling will screw into a gen-
`erally identical connector member differing only in
`coupling member 26 being a female coupling. The fiber-
`35 glass rods will then have a connector member at one
`end with a male coupling and one with a female cou-
`pling at the other end and will measure 37 feet 6 inches,
`including threaded end fittings. Generally adjacent
`coupling member 26 are a plurality of wrench flats 28 to
`40 which a standard sucker rod wrench is attached for
`coupling and uncoupling adjacent sucker rods from one
`another. A long cylindrical portion 30 having outside
`surface 32 extends from wrench flats 28 toward outer
`end 22. A cylindrical collet 34 having a diameter
`45 smaller than the diameter of cylindrical portion 30
`forms the outer end portion of connector member 12. A
`joining means shown generally at 36 joins cylindrical
`portion 30 and collet 34 and more particularly forms an
`annular surface 38 joining outside surface 32 and collet
`50 outside surface 40.
`Referring to FIGS. 3 and 4, joining means 36 and
`annular surface 38 are illustrated in greater detail. As
`shown, joining means 36 is a portion of connector mem-
`ber 12, in other words, cylindrical portion 30, collet 34
`55 and joining means 36 are formed from one continuous
`solid piece of metal. It is further, and perhaps more
`importantly noted, that annular surface 38 defines a '
`smooth curve defined by a first curve 41 with radius R1
`tangent at one end to outside surface 32. At its other end
`60 it is generally tangent to oppositely curving second
`curve 42, and second curve 42 with radius R2 is tangent
`at its other end to collet outside surface 40. While the
`embodiment of FIG. 3 illustrates R1 being smaller than
`R2, it is also within the scope of the present invention,
`65 as shown in FIG. 4, for R1 to be larger than R2. The
`prior art "joining means" had sharp beveled edges
`which were subject to cracking and breaking when
`stressed. By contrast, the present invention eliminates
`
`5 (cid:9)
`
`15
`
`30 (cid:9)
`
`This is a continuation of co-pending application Ser.
`No. 532,920 filed on Sept. 16, 1983, now abandoned.
`BACKGROUND OF THE INVENTION
`This invention relates to sucker rod constructions and
`more particularly to fiberglass sucker rods. Sucker rods
`are joined together to form a sucker rod string which
`connects a sub-surface well pump to a surface pumping
`unit. This string imparts a reciprocating pumping mo-
`tion to the sub-surface well pump. Although the sucker
`rods were generally for decades constructed from steel,
`it is now known to construct them with a fiberglass rod
`portion. An example of such a fiberglass sucker rod
`construction is found in U.S. Pat. No. 4,360,288, the
`contents of which are hereby incorporated in their en-
`tirety by reference.
`In the early 1970s, a solution was sought for the
`chemical and stress corrosion problems related to the
`use of steel sucker rods. It was found that, in addition to
`significantly reducing corrosion problems of steel
`sucker rods, the use of fiberglass rods resulted, in many
`cases, in increased production. The lighter weight of the
`rods cuts the pumping unit loads significantly and the
`reduced pumping unit load allows the pumping unit to
`operate faster. Also, the elasticity of the prestressed
`fiberglass rods string generates significant production
`increases due to the "overtravel." A weight is attached
`on the bottom of the fiberglass sucker rods, such as steel
`sucker rods or sinker bars, and this weight causes a
`higher upstroke relative to the surface stroke and a
`lower downstroke, that is, overtravel. This provides for
`a maximum overtravel whereby the pump stroke gener-
`ates a greater production. The lighter fiberglass rods
`also allows for a longer string to be used and thus
`deeper wells to be dug.
`Although the fiberglass sucker rods have resulted in
`greatly increased production and associated reduced
`pumping costs, premature fatigue failures has been a
`problem. These premature fatigue failures have oc-
`curred both in field applications and in cyclic duty tests
`of sample rods. It has also been experienced that the
`ends of the connector members would cut into the fiber-
`glass rods thereby cutting the fibers and weakening the
`rod.
`
`OBJECTS OF THE INVENTION
`Accordingly, it is the principal object of the present
`invention to provide an improved fiberglass sucker rod
`construction.
`Another object of the present invention is to provide
`an improved fiberglass sucker rod construction which is
`not subject to premature fatigue failures.
`A further object of the present invention is to provide
`a novel fiberglass sucker rod construction design.
`A still further object of the present invention is to
`provide an improved fiberglass sucker rod construction
`for the one-inch and the one and a quarter inch diameter
`fittings.
`Another object of the present invention is to provide
`a novel construction for preventing the connector mem-
`ber from digging into and thereby weakening the fiber-
`glass rods.
`Other.objects and advantages of the present invention
`will become more apparent to those persons having
`ordinary skill in the art to which the present invention
`
`Page 4 of 7
`
`

`
`4,653,953
`
`4
`present invention to have vastly greater number of
`cycles before stress fatigue results.
`In fact, in a test conducted by the Inventors, the
`following results were obtained:
`
`FITTING TEST
`Controls - Fitting with 41° tapers
`10 (All cracked)
`TM-648 Fitting (2r-4*-5i* tapers)
`(All cracked)
`TM-648 Fitting with longer sleeve
`(All cracked)
`TM-648 Fitting with Tuff Tubing in sleeve
`(All cracked)
`TM-650 Fitting (2°--4°-6° tapers)
`(5 of 12 cracked)
`
`15
`
`*AVG. CYCLES
`TO FAILURE
`42,364
`
`87,750
`
`136,105
`
`189,488
`
`1,025,935
`
`3
`this problem by providing for a novel configuration of
`annular surface 38 employing a smooth curve and more
`specifically a pair of joined and oppositely facing
`curves.
`Rod receptacle 14 defines a unique configuration. At 5
`its outer end, as best shown in FIG. 2, collet 34 has an
`inner recessed, annular surface 44 which extends a short
`distance from the end. Annular surface 44 is provided to
`hold sleeve 20 between collet 34 and fiberglass rod 16.
`Although collet 34 is adapted to snuggly hold rod 16 in
`rod receptacle 14, non-axial relative movement of collet
`34 and fiberglass rod 16 has in the past caused collet
`outer edge 46 to bite into the fiberglass and damage and
`weaken the rod. Sleeve 20 provides a protective mate-
`rial between collet outer edge 46 and the rod thereby
`preventing damage to the rod.
`At the end of rod receptacle 14 opposite collet 34 is a
`bore 48, best shown in FIG. 2, fitting closely with the
`surface of the end of the rod and together with the
`collet supporting the rod in rod receptacle 14. Wrench 20
`flats 28 ideally should be even with the outer diameter
`of bore 48. Positioned between bore 48 and collet 34 in
`rod receptacle 14 are a plurality of integrally-formed,
`axially-spaced-apart, outwardly-converging, tapered
`frusto-conical annular surfaces. Although three such
`annular surfaces 50, 52 and 54 are illustrated in FIG. 2,
`it is within the scope of the present invention to provide
`up to seven annular surfaces. These annular surfaces,
`which are recessed from rod 16, provide a series of 30
`wedge shaped cavities or chambers into which adhesive
`material 18 is positioned. Adhesive material 18 is ini-
`tially liquid when placed in the cavities and cures to
`bond to the outer surface of rod 14 and hardens to form
`a plurality of shear and compression resistant frusto- 35
`conical wedges which cooperate with the annular sur-
`faces 50, 52 and 54 and prevent the movement of rod 16
`axially out of rod receptacle 14.
`Each of the wedge shapes is defined by (1) annular
`surfaces 50, 52 or 54, (2) rod surfaces 58, 60 or 62, re-
`40
`spectively, each of which intersects at its outer end with
`its anffular surface 50, 52 or 54, respectively, and (3)
`slanted ends 66, 68, and 70. Each slanted end terminates
`at the inner end of its rod surface and the inner end of its
`annular surface. The intersection of annular surface 50 45
`and rod surface 58 defines taper angle A, annular sur-
`face 52 and rod surface 60 defines taper angle B, and
`annular surface 54 and rod surface 62 defines taper
`angle C. In the prior art it is known to make taper angles
`A, B and C equal. However, as previously discussed, 50
`these prior art sucker rods have experienced premature
`fatigue failures.
`The present invention, therefore, provides for sucker
`rods having different taper angles within each rod re-
`ceptacle. More particularly, the angles progressively 55
`increase from the outer to the inner end of the recepta-
`cle by at least one and one half degrees between adja-
`cent angles and preferably two degrees. For instance, it
`has been found, as shown below, that surprisingly in-
`creased fatigue failure resistance is experienced when 60
`angles within the above guidelines are as follows: angle
`A = 6° -± 30', angle B = 4° 30' and angle C=2° -.1.= 30'.
`Most significantly, the present invention is most evident
`when the angles are 6°, 4° and 2°, each ± about 5 min-
`utes also as shown below. These angles have been found 65
`to "even" the stresses at each of the three rod/connec-
`tor interfaces and thereby reduce the maximum equiva-
`lent stresses experienced. Thus, it is possible with the
`
`25
`
`'Average cycles is to first crack except for TM-650 fitting, contains data from 7
`good rods.
`
`It is thus seen from these test results that by having
`the tapers progressively increased by 1i° degrees the
`cycle life of the sucker rod (before all of the test rods
`crack) increases by over 100%. Further, the use of the
`Inventors longer smooth curving sleeve increases the
`cycle life an additional 50% plus, and with the tuff
`tubing an additional 40%—making for a total cycle
`improvement of about 350% over the prior art. An
`example of the preferred embodiment, wherein the
`tapers increase progressively by 2°, was also tested. The
`2°-4°-6° embodiment was chosen and after over a mil-
`lion cycles the test was concluded even though less than
`half of the test rods had cracked.
`To further improve the stress fatigue life of the sucker
`rod, the outer end of annular surface 54 shown at 64 is
`positioned directly radially inward of the tangent point
`of second curve 42 which collet outside surface 40
`shown at 65. The tolerance of the placement of outer
`end 64 and tangent point 65 should be within inch.
`From the foregoing detailed description, it will be
`evident that there are a number of changes, adaptations,
`and modifications of the present invention which come
`within the province of those persons having ordinary
`skill in the art to which the aforementioned invention
`pertains. However, it is intended that all such variations
`not departing from the spirit of the invention be consid-
`ered as within the scope thereof as limited solely by the
`appended claims.
`What is claimed is:
`1. A sucker rod construction comprising:
`a connector member being formed to define a rod
`receptacle having a closed axially inner end and an
`open axially outer end,
`said rod receptacle having a plurality of axially
`spaced, tapered annular surfaces,
`a cylindrical fiberglass rod having an end having an
`outer surface being received within said rod recep-
`tacle through said outer end and cooperating there-
`with to define an annular chamber between said
`outer surface of said end of said rod and said ta-
`pered annular surfaces, and
`a bonding means positioned in said annular chamber
`for bonding to said outer surface of said end of said
`rod to confront said tapered annular surfaces,
`each said annular surface having an angle of taper
`with respect to the outer surface of said fiberglass
`rod, and
`each said angle of taper being progressively and uni-
`formly less toward said open end by an amount
`
`Page 5 of 7
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`

`
`4,653,953
`
`5 (cid:9)
`
`30 (cid:9)
`
`5
`between one and one-half degrees and two degrees,
`inclusive,
`a collet connected to said connector member adjacent
`said open axially outer end of said rod receptacle
`and having an axial bore therethrough retaining
`said end of said rod in coaxial position within said
`rod receptacle,
`said connector member having a generally cylindrical
`outer surface,
`said collet including an axially extending tubular
`portion having an outside diameter which is
`smaller than the outside diameter of said connector
`member, and
`a joining means for joining the outside surface of said
`collet and the adjoining outside surface of said
`connector member, said joining means having an
`outer surface having a smooth concavo-convex
`curvature extending between said collet and said
`connector member.
`2. The sucker rod construction according to claim 1
`including,
`each said angle of taper being progressively less
`toward said open end by two degrees.
`3. The sucker rod construction according to claim 1
`including,
`each said annular surface being the same length.
`4. The sucker rod construction according to claim 3
`including,
`said same length being 1 inches.
`5. The sucker rod construction according to claim 1
`including,
`said annular surfaces comprising a first annular sur-
`face adjacent said closed axially inner end, a second
`annular surface axially adjacent said first annular
`surface, and a third annular surface generally adja-
`cent said open axially outer end and axially adja-
`cent said second annular surface.
`6. The sucker rod construction according to claim 2
`including,
`each said angle of taper being progressively less
`toward said open end by 2°.-± 10'.
`7. The sucker rod construction according to claim 1
`including,
`a sleeve disposed between said collet and said rod.
`8. The sucker rod construction according to claim 7
`including,
`a bore coaxially formed in said connector member
`adjacent said axially inner closed end of said rod
`receptacle inward of said annular surfaces,
`said bore being adapted to fit closely with the surface
`of said end of said rod, and
`Said collet having a passage therethrough coaxial
`with said surface of said end of said rod whereby
`said bore and said collet support said end of said
`rod at axially spaced apart points coaxially within
`said rod receptacle.
`9. The sucker rod construction according to claim 7
`including,
`said sleeve comprising a cylindrically-shaped plastic
`material.
`10. The sucker rod construction according to claim 7
`including,
`a bore coaxially formed in said connector member
`adjacent said closed axially inner end of said rod
`receptacle inward of said annular surfaces,
`said bore being adapted to fit closely with the surface
`of said end of said rod,
`
`10 (cid:9)
`
`6
`said collet having a passage therethrough coaxial
`with said surface of said end of said rod whereby
`said bore and said collet passage support said end of
`said rod at axially spaced apart points coaxially
`within said rod receptacle, and
`said sleeve being cylindrical.
`11. The sucker rod construction according to claim
`10 including,
`said sleeve comprising a plastic material.
`12. The sucker rod construction according to claim 1
`including,
`said smooth curvature comprising a first curve and an
`adjoining oppositely curving second curve.
`13. The sucker rod construction according to claim
`15 12 including,
`said first curve being tangent said outside surface of
`said connector member and said second curve
`being tangent said outside surface of said collet.
`14. The sucker rod construction according to claim
`20 13 including,
`said first curve having a radius greater than the radius
`of said second curve.
`15. The sucker rod construction according to claim
`25 13 including,
`said second curve having a radius greater than the
`radius of said first curve.
`16. The sucker rod construction according to claim
`13 including,
`said second curve being tangent to the outside surface
`of said collet at a point directly radially outward
`from the end of the outermost end of said annular
`surface.
`17. The sucker rod construction according to claim
`35 13 including,
`said second curve being tangent to said outside sur-
`face of said collet at a point directly, within ±0.125
`inches, radially outward from the end of the outer-
`most said annular surface.
`18. The sucker rod construction according to claim 1
`including,
`said collet, said connector member, and said joining
`means comprising a single continuous piece of
`metal.
`19. The sucker rod construction according to claim 7
`including, •
`said collet having an end adjacent said connector
`member and an opposite end, and
`an annular portion of said collet adjacent said oppo-
`site end being recessed away from said rod and
`being adapted to retain said sleeve between said
`collet and said rod.
`20. The sucker rod construction according to claim 7
`including,
`said collet bore spacing all said bonding means from
`said sleeve.
`21. The sucker rod construction according to claim 7
`including,
`said sleeve comprising a plastic material.
`22. The sucker rod construction according to claim
`12 including,
`said first curve facing said fiberglass rod.
`23. The sucker rod construction according to claim 1
`including,
`said rod having a rod outermost end,
`said connector member adjacent said inner end and
`said rod outermost end defining a cavity, and
`adhesive material filling said cavity.
`
`40 (cid:9)
`
`45 (cid:9)
`
`50 (cid:9)
`
`55 (cid:9)
`
`60 (cid:9)
`
`65 (cid:9)
`
`Page 6 of 7
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`
`4,653,953
`
`8
`said angle of taper of said first annular surface being
`6°
`said angle of taper of said second annular surface
`being 4°, and
`said angle of taper of said third annular surface being
`2°.
`28. The sucker rod construction according to claim 5
`including,
`said angle of taper of said first annular surface being
`5i°
`said angle of taper of said second annular surface
`being 4°, and
`said angle of taper of said third annular surface being
`2i°.
`
`* * * * *
`
`7
`24. The sucker rod construction according to claim
`23 including,
`said cavity being conical.
`25. The sucker rod construction according to claim 1
`including,
`each said angle of taper being progressively less
`toward said open end by one and one-half degrees.
`26. The sucker rod construction according to claim 2
`including,
`each said angle of taper being progressively less
`toward said open end by 2°±5'.
`27. The sucker rod construction according to claim 5
`including,
`
`5 (cid:9)
`
`10 (cid:9)
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
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`65
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`Page 7 of 7