1111111111111111111111111411111811111i1!11111111111111111111111111111
`
`(12) United States Patent (cid:9)
`Rutledge et al. (cid:9)
`
`(54) SUCKER ROD APPARATUS AND METHOD
`
`(76) Inventors: Russell P. Rutledge, Big Spring, TX
`(US); Russell P. Rutledge, Jr., Big
`Spring, TX (US); Ryan B. Rutledge,
`Big Spring, TX (US)
`
`* )
`
`Notice: (cid:9)
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 606 days.
`
`(21) Appl. No.: 13/136,715
`
`(22) Filed:
`
`Aug. 9, 2011
`
`(65)
`
`Prior Publication Data
`
`US 2013/0039692 Al (cid:9)
`
`Feb. 14, 2013
`
`(51)
`
`Int. Cl.
`E21B 43/00 (cid:9)
`F16B 7/00 (cid:9)
`F04B 53/14 (cid:9)
`E21B 17/10 (cid:9)
`F04B 47/02 (cid:9)
`B29C 65/00 (cid:9)
`B29C 65/54 (cid:9)
`B29C 65/48 (cid:9)
`B29L 31/06 (cid:9)
`(52) U.S. Cl.
`CPC (cid:9)
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`
`FO4B 53/14 (2013.01); B29C 66/5261
`(2013.01); B29C 65/542 (2013.01); E21B
`17/1071 (2013.01); B29C 65/4835 (2013.01);
`B29C 66/53 (2013.01); B29L 2031/06
`(2013.01); B29C 66/721 (2013.01); FO4B 47/02
`(2013.01); B29C 66/1246 (2013.01); B29C
`66/12441 (2013.01)
`
`(10) Patent No.: (cid:9)
`(45) Date of Patent: (cid:9)
`
`US 8,851,162 B2
`Oct. 7, 2014
`
` 166/68; 166/105; 403/265; 403/268
`USPC (cid:9)
`(58) Field of Classification Search
`USPC (cid:9)
` 166/68, 105; 403/268, 265
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,360,288 A
`4,401,396 A
`4,475,839 A
`4,653,953 A
`4,662,774 A
`4,822,201 A
`4,919,560 A
`5,253,946 A
`6,193,431 B1
`7,730,938 B2
`7,972,463 B2
`8,062,463 B2
`8,113,277 B2
`8,500,943 B2
`
`11/1982 Rutledge et al.
`8/1983 McKay
`10/1984 Strandberg
`3/1987 Anderson et al.
`5/1987 Morrow, Jr.
`4/1989 Iwasaki et al.
`4/1990 Rutledge et al.
`10/1993 Watkins
`2/2001 Rutledge
`6/2010 Rutledge
`7/2011 Rutledge
`11/2011 Rutledge et al.
`2/2012 Rutledge et al.
`8/2013 Rutledge
`
`OTHER PUBLICATIONS
`
`PCT search report for PCT/US12/00347 dated Nov. 29, 2012 (26
`pages).
`
`Primary Examiner — Giovanna Wright
`
`(57) (cid:9)
`
`ABSTRACT
`The present disclosure relates to a fiberglass rod with connec-
`tors on each end. Each connector has a rod-receiving recep-
`tacle having an open end, a closed end, and axially spaced
`annular wedge shaped surfaces such that the compressive
`forces between the rod and the respective connector are
`defined by the shape of the wedged surfaces.
`
`40 Claims, 5 Drawing Sheets
`
`10
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`100
`
`102
`104
`
`
`
`118 120
`
`122 114A
`
`112
`
`130
`116
`
`2A'
`110
`
`116
`
`122
`120
`114B
`
`22
`120
`
`114C
`
`118
`
`108
`108
`202
`200
`
`Petitioners' Exhibit 1023
`John Crane v. Finalrod
`IPR2016-01786
`Page 1 of 12
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`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`

`
`U.S. Patent (cid:9)
`
`Oct. 7, 2014 (cid:9)
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`Sheet 1 of 5 (cid:9)
`
`US 8,851,162 B2
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`10
`
`FIG. 1
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`Page 2 of 12
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`

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`U.S. Patent (cid:9)
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`Oct. 7, 2014 (cid:9)
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`Sheet 2 of 5 (cid:9)
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`US 8,851,162 B2
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`10
`
`100
`
`118 120\
`
`112
`N,
`130
`116 ,
`
`2A/
`110
`
`r
`L.
`
`116
`
`L
`
`102
`104
`122
`-7.
`3
`
`.--/4 (cid:9)
`
`114A
`
`122
`120
`114B
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`122
`120
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`114C
`
`118
`
`108
`106
`202
`200
`
`FIG.2
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`Page 3 of 12
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`

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`U.S. Patent (cid:9)
`
`Oct. 7, 2014 (cid:9)
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`Sheet 3 of 5 (cid:9)
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`US 8,851,162 B2
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`116
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`130
`
`FIG.2A
`
`—0--
`LEADING
`EDGE 1
`
`TRAILING
`EDGE 2
`
`WEDGE 1
`
`1 WEDGE 2
`
`1 (cid:9) WEDGE 3
`
`i
`
`FIG.9
`
`2
`1.8
`1.6
`1.4
`1.2
`1
`0.8
`0.6
`0.4
`0.2
`0
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`Page 4 of 12
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`

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`U.S. Patent
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`Oct. 7, 2014
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`Sheet 4 of 5
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`US 8,851,162 B2
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`G3
`
`G5 (cid:9)
`
`G7
`
`40011111111122
`100
`112
`
`FIG.3
`
`FIG.4
`
`122 G6
`100
`112
`
`4011111111111122
`100
`112
`
`N'N (cid:9)
`
`200 (cid:9)
`
`FIG-5
`
`FIG.6
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`401111111122
`100
`112
`
`FIG.7
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`FIG.8
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`Page 5 of 12
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`

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`U.S. Patent (cid:9)
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`Oct. 7, 2014 (cid:9)
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`Sheet 5 of 5 (cid:9)
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`US 8,851,162 B2
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`10
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`120
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`118
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`110
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`100
`/
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`102
`104
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`6A
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`114A
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`122B
`112
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`116B
`114B
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`122C
`116C
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`114C
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`108
`106
`202
`200
`
`FIG.10
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`Page 6 of 12
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`

`
`1
`SUCKER ROD APPARATUS AND METHOD
`
`US 8,851,162 B2
`
`2
`sub-surface pump by a string of sucker rods. The pumping
`unit moves the sucker rod string up and down to drive the
`sub-surface pump.
`Originally, a sucker rod was a special steel pumping rod. A
`sucker rod is, typically, a steel rod that is used to make up the
`mechanical assembly between the surface and the downhole
`components of a rod pumping system. Several sucker rods
`were screwed together to make up the mechanical link, or
`sucker rod string, from a beam-pumping unit on the surface to
`the subsurface pump at the bottom of a well. The sucker rods
`were threaded on each end and manufactured to dimension
`standards and metal specifications set by the petroleum indus-
`try. Typically, sucker rods have been in the lengths of 25 or 30
`feet (7.6 or 9.1 meters), and the diameter varies from 1/2 to 11/s
`inches (12 to 30 millimeters).
`Thus, sucker rod pumping is a method of artificial lift in
`which a subsurface pump located at or near the bottom of the
`well and connected to a string of sucker rods is used to lift the
`well fluid to the surface. The weight of the rod string and fluid
`is counterbalanced by weights attached to a reciprocating
`beam or to the crank member of a beam-pumping unit or by
`air pressure in a cylinder attached to the beam.
`Due to the heavy weight of the steel sucker rods, large
`pumping units were required and pumping depths were lim-
`ited. It is now preferable to use sucker rods made of fiberglass
`with steel connectors. The fiberglass sucker rods provide
`sufficient strength, and weigh substantially less than steel
`rods.
`Since the development of the fiberglass sucker rod, there
`have been continued efforts to improve the sucker rod, and
`particularly, the relationship between the steel connectors and
`the successive rods.
`FIG. 1 illustrates a generic pumping system 20. The pump-
`ing system 20 includes a pump drive 22, which is a conven-
`tional beam pump, or pump jack and is connected to a down-
`hole pump 26 through a sucker rod string 24 inserted into
`wellbore 28. The sucker rod string 24 can comprise a con-
`tinuous sucker rod 10, which extends from the downhole
`pump 26 to the pumping system 20, a series of connected
`sucker rods 10, a series of conventional length rods connected
`together, or any combination thereof. The pump drive 22
`includes a horsehead 22A, a beam 22B, a gearbox 22c and a
`motor 22D. Preferably, the sucker rod 10 is a fiberglass or
`composite rod. As described herein, the sucker rod string 24
`may be the same as the continuous sucker rod 10 when the
`continuous sucker rod 10 is a one-piece rod that extends
`substantially between the pump drive 22 and the sub-surface
`pump 26.
`FIG. 2 is a cross-sectional view of an embodiment of the
`sucker rod 10 comprising a fiber composite rod 200 and
`associated end fitting 100 within the scope of the present
`disclosure. The sucker rod 10 comprises one or more end
`fittings 100 and the fiber composite rod 200. The fiber com-
`posite rod 200 has a first end 202 and a second end (not
`illustrated).
`Typically, there are end fittings 100 on each end of the fiber
`composite rod 200 for coupling together a plurality of fiber
`composite rods 200. The end fitting 100 comprises an exterior
`surface 102, a closed end 104, an open end 106, and an
`interior surface 108. The interior surface 108 comprises a
`wedge system 110. The present disclosure provides that the
`wedge system 110 can have any number of wedges with three
`wedges preferred. The wedge system 110 defines a cavity 112
`in the end fitting 100.
`Further, the wedge system 110 comprises a plurality of
`wedged-shaped portions 114. Each wedged-shaped portion
`114 has an apex 116, a leading edge 118 and a trailing edge
`
`FIELD
`
`The present disclosure relates generally to oil well sucker
`rods. In particular, the disclosure relates to oil well sucker
`rods made of fiberglass with connectors on each end and the
`manufacture thereof.
`
`5
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`10
`
`15
`
`20
`
`The accompanying drawings, which are incorporated in
`and constitute a part of the specification, illustrate preferred
`embodiments of the disclosure and together with the general
`description of the disclosure and the detailed description of
`the preferred embodiments given below, serve to explain the
`principles of the disclosure.
`FIG. 1 illustrates a typical pumping system for use with the
`technology of the present disclosure.
`FIG. 2 is a cross-sectional view of an embodiment of a
`sucker rod and an associated end fitting within the scope of
`the present disclosure.
`FIG. 2A is an exploded view of the angle A between the
`leading edge and the trailing edge of a wedged-shaped por- 25
`tion of the wedge system.
`FIG. 3 is a sectional view of the sucker rod and end fitting
`combination illustrated in FIG. 2 taken along the section line
`3-3.
`FIG. 4 is a sectional view of the sucker rod and end fitting 30
`combination illustrated in FIG. 2 taken along the section line
`4-4.
`FIG. 5 is a sectional view of the sucker rod and end fitting
`combination illustrated in FIG. 2 taken along the section line
`5-5. (cid:9)
`FIG. 6 is a sectional view of the sucker rod and end fitting
`combination illustrated in FIG. 2 taken along the section line
`6-6.
`FIG. 7 is a sectional view of the sucker rod and end fitting
`combination illustrated in FIG. 2 taken along the section line 40
`1-7.
`FIG. 8 is a sectional view of the sucker rod and end fitting
`combination illustrated in FIG. 2 taken along the section line
`8-8.
`FIG. 9 is a graph of the relationship between the length of 45
`the leading edge and trailing edge of each wedged-shaped
`portion in the wedge system of the present disclosure.
`FIG. 10 is a cross-sectional view of another embodiment of
`a sucker rod and an associated end fitting within the scope of
`the present disclosure. (cid:9)
`The depicted embodiments of the sucker rod and associ-
`ated connectors are described below with reference to the
`listed Figures.
`The above general description and the following detailed
`description are merely illustrative of the generic disclosure, 55
`and additional modes, advantages, and particulars of this
`disclosure will be readily suggested to those skilled in the art
`without departing from the spirit and scope of the disclosure.
`
`35
`
`50
`
`DETAILED DESCRIPTION OF THE (cid:9)
`EMBODIMENTS
`
`60
`
`In many oil wells, the pressure in the oil reservoir is not
`sufficient to lift the oil to the surface. In such cases, it is
`conventional to use a sub-surface pump to force the oil from 65
`the well. A pumping unit located at the surface drives the
`sub-surface pump. The pumping unit is connected to the
`
`Page 7 of 12
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`

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`US 8,851,162 B2
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`4
`3
`fiber composite rod 200 is illustrated in the end fitting 100.
`120 extending from the apex 116. Each apex 116 forms a
`The end fitting 100 defines the leading edge 118B and the
`perimeter 122 within the cavity 112 that is the narrowest part
`of the cavity 112 associated with each wedge shaped portion (cid:9)
`trailing edge 120B to form the cavity 112. The angle between
`the leading edge 118B and the trailing edge 120B defines the
`114. The leading edge 118 is longer than the trailing edge 120
`with the leading edge 118 facing the open end 106 and the 5 angle A. Generally, the leading edge 118, the trailing edge
`trailing edge 120 facing the closed end 104 with respect to
`120 and the fiber composite rod 200 form a scalene triangle
`each wedge shaped portion 114. (cid:9)
`with the longest side of the scalene triangle being along the
`The first wedge shaped portion 114A is proximate to the
`fiber composite rod 200, the shortest side of the scalene
`closed end 104 for receiving compressive forces that are (cid:9)
`triangle being along the trailing edge 120, and the intermedi-
`greater than the compressive forces associated with the other 10 ate side of the scalene triangle being along the leading edge
`wedged-shaped portion 114B, C. Particularly, the first
`118.
`wedged-shaped portion 114A receives greater compressive
`FIG. 3 is a sectional view of the fiber composite rod 200
`forces than the compressive forces for which a second wedge (cid:9)
`and end fitting 100 combination illustrated in FIG. 2 taken
`shaped portion 114B receives that is proximate to the first (cid:9)
`along the section line 3-3. The end fitting 100 is exterior of the
`wedged-shaped portion 114. A third wedge shaped portion 15 fiber composite rod 200 with the cavity 112 there between.
`114C between the second wedge shaped portions 114B and
`The cavity 112 between the fiber composite rod 200 and the
`the open end 106 receives compressive forces that are less (cid:9)
`end fitting 100 forms a gap G3.
`than the compressive forces associated with the first and
`FIG. 4 is a sectional view of the fiber composite rod 200
`second wedge shaped portions 114A, 114C. Therefore, the (cid:9)
`and end fitting 100 combination illustrated in FIG. 2 taken
`compressive forces create a force differential along each 20 along the section line 4-4. The end fitting 100 is exterior of the
`wedge shaped portion 114 greater at the closed end 104 of the
`fiber composite rod 200 with the cavity 112 there between.
`end fitting 100 and decreasing toward the open end 106 of the
`The cavity 112 between the fiber composite rod 200 and the
`end fitting 100. (cid:9)
`end fitting 100 forms a gap G4. The gaps G3 and G4 are
`As the compressive forces associated with the first (cid:9)
`associated with the first wedged-shaped portion 114A of the
`wedged-shaped portion 114A deteriorate the structural integ- 25 wedge system 110.
`rity of the first wedged-shaped portion 114A, then, it has been
`FIG. 5 is a sectional view of the fiber composite rod 200
`found that the uncompensated for compressive forces of the (cid:9)
`and end fitting 100 combination illustrated in FIG. 2 taken
`first wedged-shaped portion 114A are transferred to and
`along the section line 5-5. The end fitting 100 is exterior of the
`accepted by the second wedged-shaped portion 114B. Simi- (cid:9)
`fiber composite rod 200 with the cavity 112 there between.
`larly, as the compressive forces associated with the second 30 The cavity 112 between the fiber composite rod 200 and the
`wedged-shaped portion 114B deteriorate the structural integ- (cid:9)
`end fitting 100 forms a gap G5.
`rity of the second wedged-shaped portion 114B, then it has
`FIG. 6 is a sectional view of the fiber composite rod 200
`been found that the uncompensated for compressive forces of
`and end fitting 100 combination illustrated in FIG. 2 taken
`the second wedged-shaped portion 114B are transferred to (cid:9)
`along the section line 6-6. The end fitting 100 is exterior of the
`and accepted by the third wedged-shaped portion 114C. (cid:9)
`35 fiber composite rod 200 with the cavity 112 there between.
`Thus, a force transfer continuum is created by the wedge
`The cavity 112 between the fiber composite rod 200 and the
`system 110. The force transfer continuum provides for a (cid:9)
`end fitting 100 forms a gap G6. The gaps G5 and G6 are
`constant effectiveness between the end fitting 100 and the (cid:9)
`associated with the second wedged-shaped portion 114B of
`fiber composite rod 200 as the wedge system 110 deteriorates (cid:9)
`the wedge system 110.
`from one wedged-shaped portion 114 to the next wedged- 40 (cid:9)
`FIG. 7 is a sectional view of the fiber composite rod 200
`shaped portion 114 of the wedge system 110. (cid:9)
`and end fitting 100 combination illustrated in FIG. 2 taken
`The sucker rod 10 has a plurality of longitudinal cross- (cid:9)
`along the section line 7-7. The end fitting 100 is exterior of the
`sections of the wedged-shaped portions 114, which forms a
`fiber composite rod 200 with the cavity 112 there between.
`plurality of frustro-conical shapes within the cavity 112. (cid:9)
`The cavity 112 between the fiber composite rod 200 and the
`The wedge shaped portions 114 of the sucker rod 10 create 45 end fitting 100 forms a gap G7.
`different compressive forces on each respective edge 118, (cid:9)
`FIG. 8 is a sectional view of the fiber composite rod 200
`120 thereof with the compressive force being approximately (cid:9)
`and end fitting 100 combination illustrated in FIG. 2 taken
`proportional to a length of each edge 118, 120. In one embodi- (cid:9)
`along the section line 8-8. The end fitting 100 is exterior of the
`ment, the compressive force on each edge 118, 120 is directly
`fiber composite rod 200 with the cavity 112 there between.
`proportional to the length of each edge 118, 120. Further, the so The cavity 112 between the fiber composite rod 200 and the
`plurality of wedge shaped portions 114 are determined by the (cid:9)
`end fitting 100 forms a gap G8. The gaps G7 and G8 are
`angle associated between the leading edge 118 and the trail- (cid:9)
`associated with the second wedged-shaped portion 114C of
`ing edge 120. (cid:9)
`the wedge system 110.
`An adhesive or epoxy 130 is used to sufficiently bond with
`The smaller gaps G3, G5, G7 associated with each wedged-
`the fiber composite rod 200 and engage with the end fitting 55 shaped portion 114 are substantially constant having essen-
`100. It is appreciated that any adhesive substance that will
`tially the same dimension. Similarly, the larger gaps G4, G6,
`sufficiently bond with the fiber composite rod 200 and engage
`G8 associated with each wedged-shaped portion 114 are sub-
`with the end fitting 100 may be used. The adhesive or epoxy (cid:9)
`stantially constant having essentially the same dimension.
`130 is placed in the cavity 112 and cured to bond with the fiber
`The symmetry provided by the relationship of the minimum
`composite rod 200 in the cavity 112 for fixedly securing the 60 gaps G3, G5, G7 and the maximum gaps G4, G6, G8 provides
`end fitting 100 with the fiber composite rod 200. (cid:9)
`unforeseen results. Particularly, the symmetry provided by
`In one embodiment, the angle A between the leading edge (cid:9)
`the relationship of the minimum gaps G3, G5, G7 and the
`118 and the trailing edge 120 of each wedge shaped portion is (cid:9)
`maximum gaps G4, G6, G8 greatly enhances the stability and
`obtuse. FIG. 2 illustrates an angle A associated with each
`ability of the fiber composite rod 200 and end fitting 100
`wedged-shaped portion 114 of the wedge system 110. (cid:9)
`65 combination to accept enhanced compressive and back pres-
`FIG. 2A is an exploded view of the angle A of the second
`sure forces associated with the reciprocating environment in
`wedged-shaped portion 114B of the wedge system 110. The (cid:9)
`which the sucker rods 10 are used.
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`Page 8 of 12
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`
`US 8,851,162 B2
`
`5
`FIG. 9 is a graph of the relationship between the length of
`the leading edge 118 and trailing edge 120 of each wedged-
`shaped portion 114 in the wedge system 110 of the present
`disclosure. As illustrated in FIG. 2, the leading edge 118 is
`progressively longer from the closed end 104 of the end fitting
`100 to the open end 106 of the end fitting 100. Similarly, the
`trailing edge 120 is progressively longer from the closed end
`104 of the end fitting 100 to the open end 106 of the end fitting
`100. The functions defined by these relationships are illus-
`trated in FIG. 9. Particularly, a line having a slope or gradient
`defines the function associated with the trailing edge 120, and
`a line having a slope or gradient defines the function associ-
`ated with the leading edge 118.
`The relationship of the function associated with the trailing
`edge 120 and the function associated with the leading edge
`118 provides insight to the unforeseen effectiveness of the
`wedge system 110 of the present disclosure. It has been found
`that the rate of increase of the length of the leading edge 118
`with respect to the rate of increase of the length of the trailing
`edge 120, as defined by the slope or gradient of each associ-
`ated function, provides an enhanced sucker rod 10 and sucker
`rod system. The slope of the leading edge 118 associated with
`the wedge system 110 of the present disclosure is greater than
`the slope of the trailing edge 120 associated with the wedge
`system 110 of the present disclosure.
`The wedge system 110 of the present disclosure as applied
`to a sucker rod 10 provides unforeseen effectiveness not
`before appreciated. The combination of the wedged-shaped
`portions 114, the relationship of the leading edge 118 to the
`trailing edge 120, the symmetry of the minimum gaps G3, G5,
`G7 and the maximum gaps G4, G6, G8 result in a wedge
`system 110 that provides improved and unpredicted function-
`ality. Particularly, the improved and unpredicted functionality
`of the sucker rod 10 having the wedge system 110 of the
`present disclosure greatly enhances the stability of the sucker
`rod 10 and ability of the fiber composite rod 200 and end
`fitting 100 combination to accept enhanced compressive and
`back pressure forces associated with the reciprocating envi-
`ronment in which the sucker rods 10 are used.
`FIG. 10 is a cross-sectional view of another embodiment of
`a sucker rod 50 and associated end fitting 100 within the scope
`of the present disclosure. The sucker rod 50 comprises one or
`more end fittings 100 and a fiber composite rod 200. The fiber
`composite rod 200 has a first end 202 and a second end (not
`illustrated).
`Typically, there are end fittings 100 on each end of the fiber
`composite rod 200 for coupling together a plurality of fiber
`composite rods 200. The end fitting 100 comprises an exterior
`surface 102, a closed end 104, an open end 106, and an
`interior surface 108. The interior surface 108 comprises a
`wedge system 110. The present disclosure provides that the
`wedge system 110 can have any number of wedges as indi-
`cated by the broken line between the first wedged-shaped
`portion 114A and the second wedged-shaped portion 114B.
`The wedge system 110 defines a cavity 112 in the end fitting
`100.
`The wedge system 110 comprises a plurality of wedged-
`shaped portions 114. Each wedged-shaped portion 114 has an
`apex 116, a leading edge 118 and a trailing edge 120 extend-
`ing from the apex 116. Each apex 116 forms a perimeter 122
`within the cavity 112 that is the narrowest part of the cavity
`112 associated with each wedge shaped portion 114. The
`leading edge 118 is longer than the trailing edge 120 with the
`leading edge 118 facing the open end 106 and the trailing
`edge 120 facing the closed end 104 with respect to each
`wedge shaped portion 114.
`
`10
`
`30 (cid:9)
`
`6
`The first wedge shaped portion 114A is proximate to the
`closed end 104 for receiving compressive forces that are
`greater than the compressive forces associated with the other
`wedged-shaped portions 114B, C, etc. Particularly, the first
`5 wedged-shaped portion 114A receives greater compressive
`forces than the compressive forces for which a second wedge
`shaped portion 114B receives that is proximate to the first
`wedged-shaped portion 114A. A third wedge shaped portion
`114C between the second wedge shaped portions 114B and
`the open end 106 receives compressive forces that are less
`than the compressive forces associated with the first and
`second wedge shaped portions 114A, 114C. Therefore, the
`compressive forces create a force differential along each
`15 wedge shaped portion 114 greater at the closed end 104 of the
`end fitting 100 and decreasing toward the open end 106 of the
`end fitting 100.
`As the compressive forces associated with the first
`wedged-shaped portion 114A deteriorate the structural integ-
`20 rity of the first wedged-shaped portion 114A, then it has been
`found that the uncompensated for compressive forces of the
`first wedged-shaped portion 114A are transferred to and
`accepted by the second wedged-shaped portion 114B. Simi-
`larly, as the compressive forces associated with the second
`25 wedged-shaped portion 114B deteriorate the structural integ-
`rity of the second wedged-shaped portion 114B, then it has
`been found that the uncompensated for compressive forces of
`the second wedged-shaped portion 114B are transferred to
`and accepted by the third wedged-shaped portion 114C.
`Thus, a force transfer continuum is created by the wedge
`system 110 regardless of the number of wedged-shaped por-
`tions 114 comprise the wedge system 110. The force transfer
`continuum provides for a constant effectiveness between the
`end fitting 100 and the fiber composite rod 200 as the wedge
`35 system 110 deteriorates from one wedged-shaped portion 114
`to the next wedged-shaped portion 114 of the wedge system
`110.
`The wedge shaped portions 114 of the sucker rod 50 create
`different compressive forces on each respective edge 118,
`40 120 thereof with the compressive force being approximately
`proportional to a length of each edge 118, 120. In one embodi-
`ment, the compressive force on each edge 118, 120 is directly
`proportional to the length of each edge 118, 120. Further, the
`plurality of wedge shaped portions 114 are determined by the
`45 angle associated between the leading edge 118 and the trail-
`ing edge 120.
`An adhesive or epoxy 130 is used to sufficiently bond with
`the fiber composite rod 200 and for engagement with the end
`fitting 100. It is appreciated that any adhesive substance that
`so will sufficiently bond with the fiber composite rod 200 and
`engage with the end fitting 100 may be used. The adhesive or
`epoxy 130 is placed in the cavity 112 and cured to bond with
`the fiber composite rod 200 in the cavity 112 for fixedly
`securing the end fitting 100 with the fiber composite rod 200.
`In one embodiment, the angle A between the leading edge
`118 and the trailing edge 120 of each wedge shaped portion is
`obtuse. FIG. 2A illustrates an angle A associated with each
`wedged-shaped portion 114 of the wedge system 110 with
`respect to the present disclosure.
`The longitudinal cross sections of the concaved portions
`110 form frustro-conical shapes. The concaved portions 110
`create different compressive forces on each respective surface
`thereof with the compressive force being approximately pro-
`portional to the length of each surface. The compressive force
`65 on each surface increases toward the closed end 104 and
`decreases toward the open end 106. The compressive force on
`each first surface 118 is proportional to the length of each
`
`55 (cid:9)
`
`60 (cid:9)
`
`Page 9 of 12
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`

`
`US 8,851,162 B2
`
`35 (cid:9)
`
`8
`7
`The method for manufacturing a sucker rod wherein each
`surface. The compressive force on each second surface 120 is
`proportional to the length of each second surface. (cid:9)
`wedge shape has a length proportional to the compressive
`force applied to the wedge shape. The method for manufac-
`The plurality of concaved portions 110 are determined by
`the angle associated between the first surface 118 and the (cid:9)
`turing a sucker rod wherein each wedge shape has a length
`second surface 120 of each concaved surface 110. The angle 5
`that increases from the closed end to the open end of the end
`fitting. The method for manufacturing a sucker rod wherein
`between the first surface 118 and the second surface 120 of
`each concaved surface 110 is obtuse. Further, each wedge (cid:9)
`each wedge shape has a length that decreases from the closed
`shape portion 114 may have a length proportional to the (cid:9)
`end to the open end of the end fitting.
`The invention has been shown in only one of its embodi-
`compressive force applied to the wedge shape 114. The
`wedge shape 114 has a length that increases from the closed 10 ments. It should be apparent to those skilled in the art that the
`end 104 to the open end 106 of the end fitting 100. The wedge
`invention is not so limited, but is susceptible to various
`shaped portions 114 may have a length that decreases from (cid:9)
`changes and modifications without departing from the spirit
`the closed end 104 to the open end 106 of the end fitting 100. (cid:9)
`of the invention.
`In yet another embodiment, a method for manufacturing a
`It is understood that the steps of the method described
`sucker rod is provided. The method comprises the steps of 15 above or as claimed is not required to be performed in the
`constructing an end fitting comprising an exterior surface, a (cid:9)
`order as disclosed. It is further understood that not all of the
`closed end, an open end, and an interior surface. The interior (cid:9)
`steps are necessary to carry out the claimed method and
`surface comprises at least three wedge shaped portions defin- (cid:9)
`different embodiments of the method may not use all of the
`ing a cavity. The wedge shaped portions have an apex and a (cid:9)
`steps as disclosed above.
`first and second length extending from the apex. The apex 20 (cid:9) While the present disclosure has been described with
`forms a perimeter that is the narrowest part of the cavity (cid:9)
`emphasis on certain embodiments, it should be understood
`associated with each wedge shaped portion such that the first
`that within the scope of the appended claims, the present
`length is longer than the second length with the first length
`locating sub system and method could be practiced other than
`facing the open end and the second length facing the closed
`as specifically described herein. Thus, additional advantages
`end with respect to each wedge shaped portion. The method 25 and modification will readily occur to those skilled in the art.
`further comprises engaging an end of a fiber composite rod
`The disclosure in its broader aspects is therefore not limited to
`into the cavity of the end fitting for creating a void between (cid:9)
`the specific details, representative apparatus, and the illustra-
`the fiber composite rod and the wedge shaped portions of the (cid:9)
`tive examples shown and described herein. Accordingly, the
`end fitting. Thereafter, injecting an epoxy into the void to
`departures may be made from the details without departing
`bond with the fiber composite rod and to fixedly engage the 30 from the spirit or scope of the disclosed general inventive
`wedge shaped portions of the end fitting for securing the end
`concept.
`fitting to the fiber composite rod. This arrangement causes the
`What is claimed is:
`stress to increase the elastic limit without permanent alter- (cid:9)
`1. An end fitting for a sucker rod comprising:
`ation of the fiber composite rod and epoxy combination in the (cid:9)
`an exterior surface, a closed end, an open end, and an
`cavity of the end fitting. (cid:9)
`interior surface,
`Thus, a first wedge shaped portion proximate to the closed
`the interior surface comprising a wedge system defining a
`end receives compressive forces that are greater than the (cid:9)
`cavity, wherein the wedge system comprises three
`compressive forces for which a second wedge shaped portion (cid:9)
`wedge shaped portions having an apex, a leading edge
`proximate to the open end receives, and an intermediate (cid:9)
`and a trailing edge, each apex forming a perimeter of
`wedge shaped portion between the first and second wedge 40 (cid:9)
`equal dimension within the cavity that is the narrowest
`shaped portions for receiving compressive forces that are (cid:9)
`part of the cavity associated with each wedge shaped
`intermediate of the first and second wedge shaped portions. (cid:9)
`portion such that the leading edge is longer than the
`Such that the compressive forces create a force differential
`trailing edge with the leading edge facing the open end
`along the wedge shaped portion greater at the closed end of
`and the trailing edge facing the closed end with respect
`the fitting and decreasing toward the open end of the fitting. 45 (cid:9)
`to each wedge shaped portion,
`The method for manufacturing a sucker rod may further (cid:9)
`wherein the leading edge is shorter at the closed end and
`comprise the step of creating different compressive forces on
`increases progressively from the closed end to the open
`each respective surface of the wedge shaped portions with the (cid:9)
`end thereby compensating for a compression of the
`compressive force being approximately proportional to the (cid:9)
`sucker rod in the end fitting, the trailing edge is shorter at
`length of each surface. (cid:9)
`the closed end and increases progressively from the
`Further, the method for manufacturing a sucker rod may (cid:9)
`closed end to the open end thereby compensating for a
`comprise the step of the compressive force on each surface
`back pressure associated with the sucker rod in the end
`incre