US2619393A - Well swab - Google Patents

Description

Nov. 25, 1952 R. A. WILSON ETA].

WELL SWAB 2 SHEETS-SHEET 1 Filed 001;. 20, 1947 Robert A. Wilson James A Wilson d, v 7 2A m.

R. A. WILSON ETAL Nov, 25, 1952 WELL SWAB 2 SHEETSSHEET 2 Filed Oct. 20. 1947 Robert" A Hf/son James A Wilson Mama Patented Nov. 25, 1952 UNITED STATES PATENT GFFEQE WELL SWAB Robert A. Wilson and James A. Wilson, Dallas, Tex.

Application October 20, 1947, Serial No. 780,960

8 Claims. (Cl. 30933) 1 This invention relates to new and useful improvements in well swabs and particularly the packing or cup elements thereof.

One object of the invention is to provide an improved well swab which includes a metallic jacket or sleeve, slit or cut longitudinally to permit circumferential or radial deforming or distortion, whereby said sleeve takes the wear and conforms to the internal irregularities of the tubing, in combination with an elastic cup or member surrounded by the jacket, which coacts with the sleeve in distributing and carrying the liquid load.

Another object of the invention is to provide an improved well swab which includes an exterior, metallic protecting jacket or sleeve, having longitudinal slits or cuts and an elastic cup or member molded in the jacket, whereby the elastic material of the cup or member fills the slits or cuts and seals them against leakage.

A further object of the invention is to provide a reinforced well swab, of the character described, wherein the metallic jacket or sleeve is cut or slit longitudinally to give it the desired flexibility and which has its upper portion, beyond said slits, reduced to form resilient fingers or wickers, thereby providing openings for the passage of fluid, as well as a means of securing the upper end of the jacket in place.

Still another object of the invention is to provide an improved well swab having an elastic cup enclosed in a metallic jacket, whereby the wall thickness of the cup may be reduced since the jacket takes the wear and the major portion of the radial thrust of the liquid load in the cup or hollow member.

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 an elevation of a swab construction in accordance with the invention,

Fig. 2 is a longitudinal sectional view of the swab,

Fig. 3 is an elevation of the metallic jacket,

Fig. 4 i a horizontal, cross-sectional view, takon on the line l4 of Fig. 3,

Fig. 5 is a horizontal, cross-sectional view, taken on the line 5-5 of Fig. 1,

Fig. 6 is a horizontal, cross-sectional view, taken on the line 6-6 of Fig. 1,

Fig. '7 is a view, partly in elevation and partly in section, illustrating a modified form of the invention,

Fig. 8 is a view, similar to Fig. '7, of another modification of the invention,

Fig. 9 is a horizontal, cross-sectional view, taken on the line 9-9 of Fig. 8, and

Fig. 10 is a view, partly in elevation and partly in section, showing a modification of the lower portion of one of the cups and its jacket.

In the drawings, the numeral It designates a tubular mandrel or support disposed axially of the swab and having its ends screw-threaded. At its medial portion, the mandrel has a cylindrical enlargement H. An elastic cup or hollow member 12 surrounds the mandrel and may be made of any suitable material such as rubber, synthetic rubber, soft plastic or the like. The cup is generally cylindrical in shape, but is subject to considerable variation in form and shape.

As shown in Figs. 1 to 6, the cup has a cylindrical wall l3 and a reduced or frusto-conical bottom [4, which is annular so as to engage snugly around the mandrel. An upstanding, annular flange or lip I5 is formed on the inner periphery of the cup bottom M for sealingly engaging the mandrel. The upper end of the cup is internally beveled to form an annular lip it, which terminates a substantial distance below the upper end of the enlargement II.

The important feature of the invention is a metallic sleeve or jacket I! which snugly encloses and surrounds the cup. This jacket is preferably made of steel or other suitable metal and includes a medial cylindrical wall or portion I3 and a reduced or frus-to-conical, annular bottom l9, which is formed with a socket 2E] shaped to receive the bottom [4 of the cup.

The cylindrical wall It is formed With regularly spaced longitudinal kerfs or slits 2| which are narrow and which extend down into the socket portion 26. By reason of the slits, the cylindrical Wall is divided into a. plurality of elongate or longitudinal panels 22 which are substantially coextensive with the cup. This structure permits the jacket to deform or distort circumferentially or radially so that the cylindrical wall I8 adapts itself to irregularities in the bore of the well pipe (not shown) and also assures a sufficient seal with said bore, when the swab is loaded, so as to prevent undesirable Icy-passing of the fluid. The cylindrical panelled wall I8 of the jacket constitutes, not only a wearing surface, but a sealing or working surface; the individual panels 22 being forced into sealing contact with the inner surface of the tubing by the radial expansion of the elastic cup l2, when the latter is loaded.

The upper portion of the jacket is out out on each side of the slits to form reduced fingers 23 with elongate openings 24 therebetween. These reduced fingers are readily bent or sprung inwardly so as to surround a frusto-conical collar or retaining member 25 mounted on the mandrel and resting upon the shoulder formed by the enlargement II, or in any other suitable member. A head or fixture 28 is screwed onto the upper end of the mandrel and has a cage 21 and a screw-threaded pin 28, as is common in this art. Below the head, a thimble or bowl 29, encircles the mandrel and has a bore conforming to the collar 25, but of larger diameter so as to provide an annular space therebetween, in which the upper ends of the fingers 23 are confined. A foot valve fixture 30 is screwed onto the lower end of the mandrel and engages the bottom 9 ofthe jacket, whereby the packet is confined on said mandrel. p

The jacket I! is first formed in the shapeshown in Fig. 3. The elastic cup I2 is preferably molded in the jacket and bonded thereto. The elastic material fills the slits 2| and thus seals them. Qwing to the protection and reinforcing afforded by the metal jacket, the cylindrical wall [3 of the cup may be comparatively thin. If desired, suitable fabric l2 may be embedded in the lower portion of the cup to reinforce and prevent cold flowing of the same under pressure.

When the cup and jacket unit is placed on the mandrel Hi, the fingers 23 are bent or sprung inwardly against the collar 25 and received in the bowl 29, when the fixture26 is screwed onto said mandrel. If desired the fixture 26 mayv first be secured on the mandrel and the. unit then slit upwardly so that the fingers enter the socket, after which the fixture 30 is applied. Owing to the reduced bottom [9 of the jacket and the inwardly bent fingers 23, only thecylindricalwall I8 of said jacket engages the inner surface of the well pipe and the swab will thus readily pass obstructions.

For some uses, it may not be desirable to use a cup and in Fig. 7 an elastic hollow member or barrel 3| is shown. The barrel is similar in construction to the cup [2, except that both ends ar formed like the bottom of said cup and have similar internal, annular lips I for sealing off around an axial mandrel ID. A complementary jacket 32 surrounds the barrel 3| and has each end 33 reduced like the bottom IQ of the jacket IT with sockets or recesses 34 formed therein for snugly receiving the ends of said barrel. Longitudinal slits or cuts 2| extend into the reduced ends 33 of the jacket to provide flexible panels 22 similar to the panels 22 of the jacket I1. There is, of course, some clearance between the jacket 32 and the inner wall of the well pipe (not shown) to facilitate lowering of this form of swab through said well pipe. One or more ports 35 are formed in the mandrel ID for exposing the barrel to the well fluids so as to expand and distort said barrel. The head 26 directly engages the upper reduced end of the jacket.

A modified form of swab is shown in Figs. 8 and 9 and includes an elastic hollow member or cup 36, similar to the cup l2, which is surrounded by a somewhat similar jacket or sleeve 31. The cup 36 has an internal, annular lip 38 for sealing off around a mandrel 39 and its upper end is beveled to provide a lip 40 similar to the lip I5. The jacket 3'! includes longitudinal slits 4 I, panels 42 and fingers 43 with the latter being welded or otherwise secured within an annular retaining 4 member or ring 44. The head 23 is in direct engagement with the ring 44 which functions in the same manner as the collar 25 and thimble 29. In fact, the latter elements are interchangeable with the ring and either type of retaining means may be employed with either form of the invention. However, the coacting collar and thimble provide greater flexibility. Instead of the annular bottom I9, the slits 4| and panels 42 extend throughout the reduced lower end of the jacket 31 to provide inwardly-disposed extensions or fingers 45. The lower end of the cup 36 is also elongated or extended as shown by the numeral 46 and the panel extensions 45 are preferably embedded or molded therein. For confining the panel extensions, an inverted thimble 41 is confined upon the mandrel 39 by the fixture 30 in surrounding relation to said extensions. The internal diameter of the thimble 41 is greater than the external diameter of the panel and cup extensions to provide an annular space 48 therebetween, whereby limited outward movementof said extensions is permitted upon expansion of the panels and cup. Due to the flexible mounting of the extensions, permanent distortion or breakage of the panels is reduced to a'mmimum.

,In Fig. 10, a slight modification of the. invention is shown and includes an elastic hollow member or cup 45 similar to the cup 33 'and surrounded by a similar-jacket :50. An internal, annular lip or flange 5| projects upwardly from the lower end of the cup 49 for sealing off around the mandrel 39, while the upper end of said cup is internally beveledto provide a lip 52 similar to the lip 16. If desired, the wallof the cup may be relatively thick and of constantinternal and external diameters. The jacket 50 includes longitudinal slits 53, panels 54 and fingers 55, similar to the slits2l, panels 22 and fingers 23 of the cup H, and the upper ends of said fingers 55 are adapted to be confined by either of the retaining members 29 and 44. It is pointed out that the slits 53 and panels 54 extend well into the reduced lower end 58. of the jacket which engages the mandrel and the lower portions of said panels are embedded within the lower end of the cup. A thimble or bowl 51, having an annular, upstanding skirt 58, surrou nds thereduced lower end of the jacket below the cup and may be made integral with said. jacket although shown as a separate element. The skirt 58 encircles the lower end of the cup, which may be molded therein, so as to reinforce said cup and the portions of the jacket panels 54 embedded in the cup. When not secured to the jacket or the cup, the thimble 51 is maintained in position by the valve fixture 30.

It is particularly pointed out that the wide longitudinal panels 22, 22', 42 and '50 function in a new manner in this" art. By completely surrounding the rubber cup and not exposing portions of surface of the cup, as in Figs. 8 and 10 of my prior Patent No. 2,456,551 and Thaheld 2,144,997, Fig. 7, the cylindricalsurface' of'the rubber cup is not exposed to Contact with the pipe wall and therefore is not subjected to wear as in said patents.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as 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 we claim and desire to secure by Letters Patent is:

1. A well swab including, an axial support, an elastic cylindrical cup surrounding said support, an elongated metallic cylindrical jacket enclosing the cup, the jacket having widely spaced narrow longitudinal cuts dividing it into elongated broad deformable panels exposed on the exterior of the swab, a supporting member on the support engaging the bottom of the jacket. an annular retaining member engaging the upper end of the jacket, the lower portions of the panels being embedded within the cup, and a reinforcing member surrounding the embedded panel portions.

2. A well swab including, an axial support, a cylindrical elastic cup surrounding said support, an elongated cylindrical metallic jacket enclosing the cup, the jacket having longitudinal narrow cuts dividing it into broad elongated deformable panels exposed on the exterior of the swab, said jacket having an annular portion below its cuts surrounding the support, a supporting member on the support engaging the bottom of the jacket, longitudinal spaced fingers integral with the medial portion of the jacket above the cup, the fingers being bent inwardly, an annular retaining member engaging the upper ends of the bent fingers, the lower portions of the panels being embedded within the cup, and a reinforcing member surrounding the embedded panel portions.

3. A well swab including an axial support, an elastic hollow member surrounding the support and having the major portion of its length cylindrical with its lower end frusto-oonical, and an elongate metal jacket completely surrounding the elastic member from the bottom to the top thereof having an elongated cylindrical portion surrounding and enclosing the cylindrical length of the elastic member above its frustoconical end, the cylindrical portion of the jacket having elongate slits widely spaced circumferentially thereof and presenting wide circumferential panels along the cylindrical portion above the frusto-conical end of the elastic member, whereby the cylindrical portion of the elastic member above its frusto-conical end is completely shielded from the wall of a tubing by the slitted portion of the cylindrical portion of the jacket above the frusto-conical lower end of the elastic member, the entire cylindrical surface of the elastic member being completely shielded by the slitted cylindrical portion of the jacket.

4. A well swab including, an axial support, an elastic member surrounding the support having a vertically elongated cylindrical portion and a bottom portion of reduced diameter, and a metallic jacket completely surrounding enclosing the elastic member having a reduced bottom portion surrounding the bottom portion of the elastic member and a vertically elongated outer sealing portion thereabove having elongated closely spaced wide panels encasing the cylindrical portion of the elastic member above the reduced bottom thereof and constituting the tube engaging portion of the jacket, whereby the cylindrical surface of the elastic member is completely shielded from contacts exterior of the jacket.

5. A well swab including, an axial support, an elastic cylindrical member having a reduced annular lip at its upper end and surrounding the support, and a metallic cylindrical jacket enclosing the elastic member having narrow longitudinal slits terminating substantially at the lip of said elastic member and providing wide metallic panels shielding the plastic member and reduced fingers extending from the ends of the panels beyond the lip of the elastic member.

6. A well swab including, an axial support, an elastic cup surrounding said support, an elongate metallic jacket completely surrounding and enclosing the cup, the jacket having circumferentially spaced narrow longitudinal slits dividing the circumferential surface of the jacket into elongate wide panels, each panel exposing a broad deformable working face many times wider than the slits on each side thereof, said jacket having an annular portion below its slits surrounding the support, a supporting member on the support engaging the bottom of the jacket, longitudinal spaced fingers integral with and extending from the upper ends of the panels, each finger being of a less width than its correlated panel, and an annular retaining member engaging the upper ends of the fingers.

7. A well swab including, a tubular mandrel, a fixture mounted on the lower end of the mandrel, an elastic cup mounted on the mandrel, a metallic jacket completely surrounding and enclosing the cup and resting upon the fixture, the jacket having a cylindrical surface exposed on the exterior of the swab and provided with widely spaced longitudinal slits along said cylindrical surface, whereby said exposed surface is divided into closely spaced wide panels, transversely reduced fingers extending from the upper ends of the panels, a collar receiving the upper ends of said fingers, and a fixture mounted on the upper end of the mandrel and overhanging the fingers.

8. A well swab including, an axial support, a metallic jacket having a medial cylindrical portion formed of wide elongate panels separated by narrow longitudinal slits and constituting a complete circumferential metallic working surface, and an elastic cup disposed Within the jacket having a cylindrical portion completely surrounded and covered by the cylindrical portion of the jacket.

ROBERT A. WILSON, JAMES A. WILSON.

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

UNITED STATES PATENTS Number Name Date 1,520,400 Boynton Dec. 23, 1924 1,527,956 Mowers Feb. 24, 1925 1,757,005 Christenson May 6, 1930 1,792,898 Dillon Feb. 17, 1931 1,825,185 Greenidge Sept. 29, 1931 2,144,997 Thaheld Jan. 24, 1939 2,352,812 Taylor July 4, 1944 2,456,551 Wilson Dec. 14, 1948

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