US2305282A - Swab cup construction and method of making same - Google Patents

Description

'ec. 15, 1942. R. .c-;. TAYLOR. JR.. ET AL 2,305,282

WAB CUP CONSTRUCTIOILAND METHOD OF MAKING SAME Filed March 22, 1941' INVENTOR. RAYMOND 6 720 103 Jf? DO/VALD B. HOOJf/P Patented Dec. 15, 1942 assess?- SWAB CUP CONSTRUCTION AND METHOD or MAKING SAME Raymond G. Taylor J12, and Donald B. Hooser,

Dallas, Tex, asslgnors to The Guibcrson Corporation, Dallas, Tex,

ware

a corporation of Dela- Application March 22, 1941, Serial No. 384,873

or sea-4) 15 Claims.

This application is an improvement in the construction of and a method of making swab cups. Heretofcre considerable trouble ha been experienced in making swab cups flexible and yet preventing the resilient body from flowing. 1

A notable advance in regard to swab construction was made by C. S. Crickmer as shown in his Patent 1,735,264 in which he showed a bushing in the inner lower portion of the cup with an apron extending upwardly therefrom and embedded in the body of the cup, which greatly strengthened the cup. He also provided wires on the outside thereof and these wires likewise strengthened and supported the cup and also relieved the cup from much of the friction which would otherwise be encountered between the cup and the casing.

The present invention pertains an improvement over the type of swab cupshown .in the said Crickmer' Patent 1,735,264'while retaining all of the advantages thereof. The improvements consist principally in providing a retaining ring in the lower portion of the cup to space the wires apart at their proper distance and, to hold -these wires in firm engagement with the said bushing and in bending the upper portions of the wires inwardly so that they are embedded inthe cup itself. The cup extends a distance above the upper portions'of the wires so that the pressures to which the cup is subjected will cause the portion of the cup above the wires to seal directly against the well casing andthereby prevent leakage which might result if the wires extended to the fullheight of the cup. The wires running vertically of the cup and on the outside thereof give such a strong support to the cup that the composition resists the tendency to flow to a remarkable degree so that the swab cup can withstand enormous pressure.

Another object of the invention relates to-the method of constructing the swab cup assembly. Other objects and advantages of the invention will appear in the detailed specification and claims which follow.

The invention may be better understood by referring to the attached drawing in which,

Fig. l is a cross-sectional view of the swab cup assembly,

Fig. 2 is a side elevational view partly in crosssection of the metallic portions of the cup assembly,

3 is a cross-sectional view of the bushing, Fig. 4 is an elevational view of one of the retainins wires.

Fig. 5 is a perspective view of the retaining ring, and

Fig. 6 is a cross-sectional view on the line 6-4 of Fig. 2.

The swab cup is designed to be used with a tubular mandrel- I having an offset shoulder 2 on which is supported a thimble l; "The cup 4 is made of flexible or elastic material. In years past these cups were generally made of rubber but as rubber substitutes have been found which would resist oil, these rubber-like substitutes are now generally employed. They are generally marketed under trade-names such as Neoprene, Dupreneand other trade names. For the purpose of this invention itls, immaterial as to which one of these materials is employed; the essential feature being that the cup lsmad'e of a material which will readilyexpand into engagement with the side wallsof the. casing, lfl'l'ie'zcupls of hollow constructlon and :forms an outwardly flaring well 5 adaptedjtourecelve fluid;. inr,the well. If the mandrel is pulled upwardlyitls obvious that any fluid in the well above the cup would expand the cup radially and make a seal between the conventional casingfinotlshowmand the mandrel.

A,.bushing having a lower tubular section t is lnthe'lower portion-of thecup and forms an inner lining therefor. Extenuinasbove but integral with the tubular section is an upwardly and outwardly flaring apron 'I which is embedded in. the central portion'of the cup and forms a powerful support therefor. A somewhat similar bushing was shown in the Crickmer Patent 1,735,2641-Flg. 4.

The retaining wires i have their upper por-' tion of substantially hairpin shape. The upper portion 9 thereof is bent inwardly and embedded in the cup so that the cup has a radially flexible portion Ill above the wire. llf the cup is, therefore, subjected to excessive pressures, this upper portion ll of the cup can seal directly against the well casing, and since there are'no wires at that point'there is no tendency of the well fluid to pass downwardly by the .wires as this portion Ill makes an absolute seal. It will be noted. however, that this upper portion of the cup is strongly supported by the wires below it. Below the inwardly extending portion 9 of the retaining wires there is a substantially vertical section ll adapted to be pressed directly against the casing and since the casing extends vertically, naturally this section H of the wires on tends likewise. Below the vertical section II the wires are bent slightly inwardly taming a section I! and below the section I: the wires are bent radially inwardly and then vertically forming a lower portion II. The lower portion I3 is in direct encasement with the outer periphery of the tubular section 8. These retaining wires maybe easily manufactured by simply cutting the wires into the proper length and then bending the same into the configurations shown in Fig. 4, it being noted that the lower portions II are not united together but the upper portion 9 forms a continuation of the same wire. There are, therefore, no free ends at the upper portion but there are free ends at the lower portion.

A corrugated retaining ring ll holds the lower portions ii of the retaining wires in close engagement with the tubular section 8 of the bushing. It will be noted that this retainingring is corrugated, the valleys i5 extending vertically.

The lower portions if of the retaining wires are seated in the said valleys, which valleys are spaced equal distances apart and, therefore, serve as a means to properly space the wires. This corrugated construction of the metallic retaining ring makes the retaining ring resilient so that it acts as a powerful spring to hold-the wires in engagement with the bushing. It will further be noted that there is a considerable amount of the cup between the retaining ring [4 and the inner walls'of the thimble I. The mid-portion of the cup is, therefore, supported against excessive radial distortion by the metallic skirt I while the retaining ring supports all of the outer portion of the cup except for the extreme upper portion III of the cup and for the part of the cup beneath the sections I! of the retaining wires, and the lower portion of the cup is supported by the outwardly flaring walls of the thimble 3, the thimble extending to within a short distance of" the lower end of the sections I! of the retaining wires. The cup is, therefore, supported through the major portion of its length to prevent flow of the cup when subjected to excessive'pressures. A cup of this construction, therefore, has all of the sealing advantages of cups of prior construction and has the advantage of being adequately supported to withstand terriflc pressures and in addition has means to prevent leakage downwardly by the wires.

The cup is assembled in a most facile manner. A loose fitting temporary mandrel, not shown, is inserted in the retaining ring H and the retaining wires are then inserted so as to seat in the valleys l5 of the retaining ring. This, of

course, makes a very loose fit but properly spaces the wires apart. The bushing shown in Fig. 3 is then introduced from above and is forced downwardly pushing out the-loose fitting mandrel. The tubular section l6 of the bushing is larger than the loose fitting mandrel and it presses the wires into such tight engagement with the retaining ring that the retaining ring is caused to expand somewhat. The retaining ring is made of spring metal and the bushing forcing the lower ends of the retaining wires into engagement with the retaining ring causes the retaining ring to expand and thereby hold the wires securely in the bushing. The resultant tion shown by way of illustration herein and without departing from the spirit of the invention. We, therefore, desire to claim the invention broadly except as we may limit ourselves in the appended claims Having now described our invention, we claim:

1. A swab assembly including an elastic cup, a reinforcing bushing in the lower part of the cup, retaining wires .having their lower parts extending parallel to and contacting the bushing and embedded in the cup and a resilient retaining ring engaging and resiliently pressing the said lower parts of the wires into engagement with the bushing.

2. A swab cup assembly including a flexible cup body, a reinforcing bushing in the inner lower portion of the body and having an outa wardly extending apron embedded in said body,

retaining wires having their lower parts extending parallel to and contacting the bushing and a resilient retaining ring pressing the said lower 5 parts of the wires into engagement with the bushing.

3. A swab cup assembly including a flexible cup body, a bushing for the lower portion of the body and having an outwardly and upwardly extending apron embedded in said body, retaining wires for the bodyand having their lower portions extending along and in contact with the bushing and a resilient retaining ring hold ing the lower portion of said wires in flrm contact with the bushing.

4. A swab cup assembly including a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for the body and having their lower portions extending along and in contact with the bushing and a resilient retaining and spacing ring holding the lower portion of said wires in firm contact with the bushing and serving as a means to hold said wires spacedapart from each other.

5. In a swab cup assembly including a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for the body and having their lower portions extending along and in contact with the bushing and a stretchable, corru- 5 gated retaining ring holding the lower portion of said wires in firm contact with said bushing.

6. In a swab cup assembly including a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for the body and having their lower portions extending along and in contact with the bushing and a corrugated retaining ring holding the lower portion of said wires in flrm contact with said bushing.

7. A swab cup assembly including, a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for. the body and having their lower portion extending along and in contact with the bushing and a corrugated retaining ring of spring metal holding the lower portion of said wires in flrm contact with the bushing, the corrugations of the retaining ring forming inner channels to receive the wires.

8. A swab cup assembly including, a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for the body and having their lower portion extending along and in contact with the bushing and a corrugated retaining ring of spring metal holding the lower portion of said wires in flrm contact with the bushing, the corrugations of the retaining ring forming inner channels to receive the wires, the upper portions of said wires being bent inwardly and embedded in the upper portion of the cup body.

9. A swab cup assembly including a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for the body and having their lower portion extending along and in contact with the bushing and a corrugated retaining ring of spring metal holding the lower portion of said wires in firm contact with the bushing, the corrugations of the retaining ring forming inner channels to receive the wires, the upper upper portion of said wires extending inwardly and embedded within the cup body.

11. A swab cup assembly including a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for the body having their lower portions extending along and in contact with the bushing, a flexible corrugated retaining ring holding the lower portion of said wires in firm contact with the bushing, the upper portion of said wires extending inwardly and embedded within the cup body, and a thimble supporting the lower ends of said bushing, wires, retaining ring and cup body.

12. A swab cup assembly including a flexible cup body, a bushing for the lower portion of the body, reinforcing wires for the body having their lower portions extending along and in contact with the bushing, a flexible corrugated retaining ring holding the lower portion of said wires in firm contact with the bushing, the upper portion of said wires extending inwardly and embedded within the cup body, and a thimble supporting the lower ends of said bushing, wires, retaining ring and cup body, the retaining wires extending throughout the major portion of the height of the cup body but terminating below the top thereof.

13. The method of making a swab cup assembly consisting of placing the lower ends of wires in the valleys of the corrugations of a retaining ring, forcing a bushing into engagement with the lower ends of the wires inthe retaining ring to expand the retaining ring and molding a flexible body around a portion of the bushing, retaining ring and retaining wires.

14. The method of forming a swab cup assembly consisting of placing the lower ends of wires in the inner corrugations of a spring metal retaining ring, inserting the bushing so as to cause the retaining wires to expand the retaining ring so that the retaining ring will hold the wires in close contact with the bushing and molding a resilient plastic to said bushing, retaining wires and retaining ring.

15. A swab cup assembly including a flexible cup body, a bushing for the lower portion of the body, retaining wires for the body having their lower portions extending along and engaging said bushing for a substantial distance'and a re- RAYMOND G. TAYLOR, JR. DONALD B. HOOSER.

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