US3631895A

US3631895A - Well cap

Info

Publication number: US3631895A
Application number: US7549A
Authority: US
Inventors: Conrad R Medina; Edward A Cox
Original assignee: CLAYTON MARK AND CO
Current assignee: CLAYTON MARK Inc; CLAYTON MARK AND CO
Priority date: 1970-02-02
Filing date: 1970-02-02
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04

Abstract

A well cap for the end of a well casing includes end wall means and annular skirt wall means depending therefrom adapted to be telescoped around an upper end portion of said casing. Annular sealing chamber means are defined on an inside surface of the skirt wall means radially outwardly of the sidewall of said casing. A deformable sealing ring is mounted in the chamber means for sealing between the skirt wall and the well casing. A compression ring means in the chamber means around the sealing ring compresses the ring radially inwardly against the sidewall of the casing.

Description

United States Patent [72] Inventors [21] Appl. No. [22] Filed [45] Patented [73] Assignee [54] WELL CAP 2,099,722 1 1/1937 Byers 277/101 X 2,437,632 3/1948 Walfram.... 277/101 X 2,562,946 8/1951 Read 220/40 X 2,883,083 4/1959 Terry 138/89 X 3,028,180 4/1962 Smith 277/101 X 3,246,793 4/1966 Wade 220/46 FOREIGN PATENTS 211,526 8/1957 Australia 138/89 Primary Examiner-Herbert F. Ross Attorney-Mason, Kolehmainen, Rathburn & Wyss ABSTRACT: A well cap for the end of a well casing includes end wall means and annular skirt wall means depending therefrom adapted to be telescoped around an upper end portion of said casing. Annular sealing chamber means are defined on an inside surface of the skirt wall means radially outwardly of the sidewall of said casing. A deformable sealing ring is mounted in the chamber means for sealing between the skirt wall and the well casing. A compression ring means in the chamber means around the sealing ring compresses the ring radially inwardly against the sidewall of the casing.

WELL CAP The present invention relates to a new and improved'well cap for sealing the upper end of a well casing or the like.

It is an object of the present invention to provide a new and improved well cap adapted to be telescoped onto the upper end portion of a well casing and tightened thereon to seal and close the upper end.

Another object of the present invention is to provide a new and improved well cap of the character described having improved sealing means accessible from the exterior for tightening or loosening as desired.

Another object of the present invention is to provide a new and improved well cap of the character described including an annular sealing ring and compression ring comprising a tension band wrapped around the sealing ring for compressing the same radially inwardly against the sidewall of the well casmg.

Another object of the invention is to provide a new and improved well cap of the character described having an annular sealing ring compressible radially inwardly against the well casing and including lip means for sealing against an end wall of said well cap.

In brief, a well cap constructed in accordance with the features of the present invention comprises an end wall and an integral, annular skirt wall depending therefrom adapted to be telescoped onto an upper end portion of a well casing to close the same. An annular sealing chamber is defined on an inside surface of the skirt wall radially outwardly toward the sidewall of the casing, and downwardly of said end wall, and a deformable annular sealing ring or gasket is mounted in the chamber for sealing engagement between the outer surface of the well casing below the end and surfaces defined in the annular chamber of the skirt wall. Compression ring means comprising a tension band wrapped around the sealing ring is provided for compressing the sealing ring radially inwardly to seal against the casing and seal off the upper end of the well casing.

The invention, together with the above and other objects and advantages, may be better understood with reference to the following detailed description of an embodiment of the invention illustrated in the accompanying drawings, wherein:

FIG. 1 is a perspective view of a well cap constructed in accordance with the features of the present invention and shown installed on the upper end of a well casing;

FIG. 2 is a longitudinal sectional view taken on a plane extending through the longitudinal center line of the well casing substantially along line 2-2 of FIG. 1;

FIG. 3 is a transverse sectional view taken substantial along line 3-3 ofFIG. 2; and

FIG. 4 is a fragmentary perspective view showing a portion of an annular sealing ring means for the well cap of the present invention in its relaxed or noncompressed condition.

Referring now more particularly to the drawings, therein is illustrated a new and improved well cap constructed in accordance with the features of the present invention and adapted to seal and close the upper end of a well casing 12. The well cap 10 includes an end wall portion 14 adapted to cover the open upper end of the well casing and an integral, annular skirt wall 16 depends from the end wall. When the well cap is telescoped onto the upper end portion of the well casing 12, the skirt wall extends downwardly of the upper end of the casing.

The end wall portion 14 includes a frustoconically shaped domelike portion 18 (FIG. 1) providing an access chamber above the end of the well casing, and at the lower end the domelike portion intersects a planar, annular wall or seating surface 20 (FIG. 2) which is adapted to abut and rest upon the upper end surface of the well casing 12. At the upper end, the end wall portion 14 is formed with an externally threaded, upstanding cylindrical boss 22 having a threaded bore 24 defined therein in order to support a pipe or hanger 26 extending axially downward into the well casing 12 from the end cap. An elbow 28, or the like, may be used for connecting the interior of the end cap to a pipe conduit or other apparatus. Altematively, a cap may be threaded onto the external threads of the boss 22 when pipe 26 is used as a hanger pipe rather than a conduit.

In order to provide lateral access to the interior of the dome-like portion 18, a pair of small integral housings or projections 30 (FIG. 1) are provided, and each includes a vertical outer face 30A having an internally threaded access opening 32. The opening 32 may be closed with a suitable plug 34 if not used, and a bushing 36 or other fitting may be provided to seal around a conduit 38. In a typical installation, the conduit may be provided to shield a plurality of electrical cables 40 used for powering a pump or other apparatus inside the well casing 12.

In accordance with the present invention, the annular skirt wall 16 has an internal diameter slightly larger than the maximum outer diameter of the well casing 12 in order to permit the well cap 10 to be easily telescoped onto or over the upper end of the well casing. The skirt wall is provided with an annular recess or chamber 42 extending outwardly of and around the well casing 12 at a level spaced downwardly or below the upper end of the casing. The chamber 42 includes a generally cylindrical sidewall 42a and a pair of spaced apart annular end or top and

bottom walls

42b and 420. The upper end of the chamber 42 is in communication with the seating surface 20 on the end wall portion 14 through a narrow space defined between the internal surface of the skirt wall 16 and the outer diameter of the well casing 12.

In accordance with the present invention, in order to secure the end cap 10 in place on the well casing 12 and simultaneously to provide a gas and liquid tight seal around the upper end of the well casing, a deformable annular sealing ring 44 is seated in the annular sealing chamber 42 and extends completely around the outer surface well casing 12. The sealing ring is formed of suitable elastomeric material such as rubber and the like and includes a main body portion that is substantially rectangular in a transverse or radial cross section through the ring (FIG. 4). The ring includes an integral, relatively thin, upwardly extending sealing lip 44a which projects upwardly into the space between the outer surface of the well casing and the inside bore of the skirt wall 16.

The main body portion of the sealing ring is dimensioned to fit snugly between the walls 42b and 42c and the sealing chamber 42. However, spacing is provided between the outer periphery of the ring and the sidewall 42a of the sealing chamber. A compression ring 46 comprising a thin tension band or strip or clamp of strong flexible material such as stainless steel or the like (FIGS. 2 and 3) is wrapped around the outer circumference of the sealing ring 44. Opposite ends of the tension band are drawn toward one another to provide compression forces radially inwardly on the sealing ring 44. For this purpose opposite ends of the tension band are formed with radially outwardly extending lugs 46a and 46b (FIG. 3) having suitable apertures therein in order to receive a tension bolt 48 with a nut 48a threaded thereon.

In order to provide spacing for the lugs and bolts and nut, the annular sealing chamber 42 is provided with an extension or radially outwardly projecting housing 50 and one side of the housing is open, as at 52, in order to provide access for tightening or loosening the nut 48a on the bolt 48 thereby to adjust the compression of the band 46 on the annular sealing ring 44.

Compression of the ring 44 radially inwardly is effective to secure the well cap 10 in place on the well casing 12 and pro vide a gas tight seal around the upper end of the well casing. When the nut 48a is tightened on the bolt 48, tension on the ring 46 is increased, and this results in radial inward compression of the seal 44 against the outer surface of the well casing 12. The lip portion 440 of the seal is forced or extended upwardly into the confined region between the casing 12, the skirt wall 16, and the wall 20. The lip 44a thus seals tightly against the end wall seating surface 20 because of the offset of the lip from the main body of the seal in a longitudinal direction with respect to the axis of the well casing 12. Thus, it

can be seen that when the main body portion of sealing. ring 44 is compressed radially inwardly by increased tension exerted on the ring 46, the lip portion 44a simultaneously effects a seal against the seating surface 20 of the end wall portion 14.

The deformable elastomeric sealing ring 44 thus serves a dual purpose of physically securing the end cap tightly in place on the upper end of the well casing 12 and in addition provides a gastight seal.

The well cap 10 is easily mounted and secured tightly in place on the upper end of a well casing by first assembling the seal 44 and clamp 46 within the cap, slipping the cap over the well casing, and tightening the nut 48a to compress the sealing ring 44 radially inwardly. The well cap 10 is readily removed if desired by loosening the nut 48a and lifting the well cap upwardly from the casing. The well cap 10 provides a convenient means for physically supporting equipment in the well casing such as a submersible pump, a pipe string, or other apparatus, and the domelike portion 18 and chambers 30 accommodate the entry of tubing, electrical conduit or other utility connections into the interior of the well casing with a gastight seal being maintained. It should be noted that the relatively large interior bore surface of the sealing ring 44 and lip 44a provides excellent holding and sealing around the well casing with relatively little compression exerted on the sealing ring being required. Fluid sealing is aided by the thin sealing lip 44a in contact against the seating surface 20 on the end wall portion 14 of the well cap. The sealing ring 44 and compression band 46 are readily replaceable should they become worn or damaged.

Although the present invention has been described with reference to a single-illustrative embodiment thereof, it should be understood that numerous other modifications and em bodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A well cap for the end of a well casing comprising end wall means and annular skirt wall means depending therefrom adapted to be telescoped around an end portion of said casing; annular sealing chamber means defined by the inside surface of said skirt wall means radially outwardly of said casing; said sealing chamber defined by a cylindrical sidewall and a pair of spaced apart opposed annular top and bottom walls axially spaced from said end wall; a radially narrow extrusion zone defined between said casing and said skirt wall means and extending in an axial direction from said sealing chamber means to said end wall means; a deformable sealing ring including a first portion of a first thickness mounted in said chamber and a second portion axially offset form said first portion and having a second thickness smaller than said first thickness and extending into said extrusion zone; and separate compression means in said chamber extending around said first portion of said sealing ring for compressing said first portion of said sealing ring radially inward against said casing, said sealing chamber limiting spreading of said first portion of said sealing ring and for permitting axial extrusion of said second portion of said ring against said end wall means upon radial compresadapted to be telescoped around an end portion of said casing;

annular sealing chamber means defined on an inside surface of said skirt wall means radially outwardly of said casing; a deformable sealing ring mounted in said chamber for sealing between said skirt wall and said casing; and compression ring means 111 said chamber around said casing; and compression ring means in said chamber around said sealing ring for compressing said ring radially inward against said casing, said compression ring means including a band of thin strip material around said sealing ring and threaded connector means for pulling opposite ends of said band toward one another to compress said sealing ring radially inwardly.

5. The well cap of claim 4 wherein said sealing chamber means is formed with an access opening permitting said threaded connector means to be tightened or loosened with a tool inserted into said sealing chamber.

6. The well cap of claim 4 wherein said sealing chamber means includes a narrow extrusion zone in communication with said end wall means when said well cap is telescoped onto said casing, said sealing ring including an annular lip offset from said compression ring extending into said extrusion zone for sealing against said casing, said end wall means and surface of said extrusion zone in said chamber means.

I. The well cap of claim 4 wherein said sealing chamber means includes a pair of spaced apart, opposite sidewalls for limiting the spreading action of said sealing ring when the latter is compressed inwardly against said casing upon compression of said compression ring means.

8. A well cap for the end of a cylindrical well casing comprising an end wall, annular skirt wall means depending from said end wall and telescoped around a portion of the outside surface of said casing adjacent said end thereof; annular chamber means defined on the inside surface of said skirt wall means radially outwardly of said casing; a deformable sealing ring in said chamber means for sealing between said skirt wall means and said casing; and compression ring means around said sealing ring in said chamber for compressing said sealing ring radially inwardly against said casing, said compression ring means including a thin band of strip material wrapped around the exterior of said sealing ring and threaded connector means extended between opposite ends of said strip for exerting tension on the same to compress said sealing ring radially inwardly.

9. The well cap of claim 8 wherein said skirt wall means includes an opening therein in communication with said outer portion of said chamber means permitting access to said threaded connector means for tightening or loosening the same.

l i i

Claims

1. A well cap for the end of a well casing cOmprising end wall means and annular skirt wall means depending therefrom adapted to be telescoped around an end portion of said casing; annular sealing chamber means defined by the inside surface of said skirt wall means radially outwardly of said casing; said sealing chamber defined by a cylindrical sidewall and a pair of spaced apart opposed annular top and bottom walls axially spaced from said end wall; a radially narrow extrusion zone defined between said casing and said skirt wall means and extending in an axial direction from said sealing chamber means to said end wall means; a deformable sealing ring including a first portion of a first thickness mounted in said chamber and a second portion axially offset from said first portion and having a second thickness smaller than said first thickness and extending into said extrusion zone; and separate compression means in said chamber extending around said first portion of said sealing ring for compressing said first portion of said sealing ring radially inward against said casing, said sealing chamber limiting spreading of said first portion of said sealing ring and for permitting axial extrusion of said second portion of said ring against said end wall means upon radial compression of said compression means.

2. The well cap of claim 1 wherein said compression means comprises a band of thin strip material around said sealing ring and means for pulling opposite ends of said band toward one another to compress said sealing ring radially inwardly.

3. The well cap of claim 2 wherein said pulling means includes a threaded connector extending between the opposite ends of said band.

4. A well cap for the end of a well casing comprising end wall means and annular skirt wall means depending therefrom adapted to be telescoped around an end portion of said casing; annular sealing chamber means defined on an inside surface of said skirt wall means radially outwardly of said casing; a deformable sealing ring mounted in said chamber for sealing between said skirt wall and said casing; and compression ring means in said chamber around said casing; and compression ring means in said chamber around said sealing ring for compressing said ring radially inward against said casing, said compression ring means including a band of thin strip material around said sealing ring and threaded connector means for pulling opposite ends of said band toward one another to compress said sealing ring radially inwardly.

7. The well cap of claim 4 wherein said sealing chamber means includes a pair of spaced apart, opposite sidewalls for limiting the spreading action of said sealing ring when the latter is compressed inwardly against said casing upon compression of said compression ring means.