Water well casing

A novel design for the connection of polyvinyl chloride (PVC) casing. Each length of casing has a male end and a female end. The female end has a narrowing interior diameter with its wider interior diameter at its outermost end sufficient to receive the male end of similar length of casing for connection. The diameter of the female end narrows to a diameter which is less than the outer diameter of the male end. The male end has a lip at its leading edge and is slotted and compressible when forced through the narrowed diameter of the female end. A groove in the interior surface of the female end is sufficient to receive the lip at the leading edge of the male end. When the lip at the leading edge of the male end reaches the groove, it allows the compressed male end to expand with the groove receiving the lip therein. The connected lengths of casing are locked together in this manner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Applicant's invention relates to a novel design for water well casing for use in water well and related systems.

2. Background Information

In water well systems, a casing is inserted into the well to maintain the structure of the well. Typically, a submersible pump is placed within the well and is attached a drop pipe which carries the water from the well to the surface. Since water well casing must extend many feet into the ground, it is advantageous to manufacture the casing in sections to facilitate installation as well as repair. Generally these sections are held together with glue or a pipe coupling. Unfortunately, the positioning of couplings can take a great deal of effort to assemble properly and the use of glue is time-consuming as glue requires a “set” time. Therefore, with current practices and materials, well drillers do not have the ability to run the casing into the well by simply and rapidly connecting one section of casing to another.

The present invention was designed to solve this problem. In the preferred embodiment, water well casing sections are provided having both male and female ends. The male end of one length of casing section fits within the female end of another length of casing. The male end is slotted and compressible when forced into the female end. The male end provides a lip which locks into a groove in the interior surface of the female end when the male end is fully inserted. The procedure allows the water well casing to be connected easily and efficiently without the use of glue or couplings.

A patent issued to Potts, U.S. Pat. No. 3,413,021, discloses a similar design for metal tubular couplings. Unlike the present invention, Potts discloses a coupling which is resistant to compressive forces and can be disassembled easily when pulled apart. On the other hand, the present invention is designed to resist the pulling or hanging loads which exist when the casing is placed in the well.

A patent issued to Oldford, U.S. Pat. No. 4,128,264 also has similarities to the present invention. However, the Oldford patent discloses a design for metal fittings to be used with metal pipe as opposed to plastic PVC casing disclosed in the present invention.

The prior art is devoid of any similar designs to be used with plastic piping or casing in water well applications.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide novel water well casing that permits installation and connection without the use of glue or couplings. In satisfaction of these and related objectives, Applicant's present invention provides water well casing having a main length between male and female ends. The main length of the casing has a uniform inner and outer diameter and is contiguous with the male and female ends.

The male end has slots which are spaced around the circumference of the casing. The slots extend from the leading edge of the male end in a direction parallel to the length of the casing. The male end also has a lip at its leading edge. The lip is beveled at its front edge and forms a shoulder at its rear edge.

The female end has a first female section with a widened interior diameter at its outermost end designed to receive a male end of a similar length of casing. The interior diameter of the female end tapers and narrows to another section having a diameter which is less than outer diameter of the lip at the male end. A groove in interior surface of the female end is designed to receive and hold the lip of a similar length of casing.

During installation, the male end of one length of casing compresses as it is forced through the tapered diameter of the female end of another length of casing. Once the lip at the leading edge of the male end reaches the groove, the male end expands with the groove receiving and locking the lip therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1depicts a water well100with casing102placed in the water well100to maintain the integrity of the well100and protect pipe (not shown) within the casing102. The casing102is present in separate similar lengths of casing104and105and connected one to the next by way of male ends106and female ends108shown in more detail inFIGS. 2,3, and4.

Referring toFIGS. 1,2,3, and4, the casing102of the present invention consists of three parts, a main length107, a male end106and a female end108. In the preferred embodiment, the male end106has a tapering section110extending from the main length107to a lip112at the leading edge of the male end106. The outer diameter of the lip112is substantially equal to the outer diameter of the main length107. However, other designs of the male end are anticipated. For example, the outer diameter at the male end106could be uniform and equal to the outer diameter of the main length107with the lip112having an outer diameter greater than that of the main length107. In another example, the male end106could have a uniform diameter which is narrower than the diameter of the main length.

Preferably, the interior diameter of the male end106is equal to the interior diameter of the main length107. However, it is anticipated that the interior diameter of the male end106could be greater or less than the interior diameter of the main length107.

In the preferred embodiment, the lip112has a beveled leading edge120and a squared shoulder121at its rear edge. However, it is anticipated that other designs for the lip could be utilized. For example, the leading edge of the lip112could be squared or rounded and the rear edge of the lip112could be curved or angled rearwardly.

The male end106has slots122, which are spaced around the circumference of the male end106and extend from the lip112into the tapering section110in a direction substantially parallel to the length of the casing102. Preferably, there are a plurality of slots122equally spaced around the circumference of the male end106. However, it is anticipated that as few as one slot or a plurality of nonequally spaced slots could be utilized.

FIGS. 2 and 3show a side view and cross sectional view of the female end108of the water well casing102of the present invention whileFIG. 4illustrates a cutaway view. As shown in these views, the female end108has varying interior diameter which is wider at its outermost end. A first female section130is located at the outermost end of female end108. The first female section130has a widened interior diameter132sufficient to receive the male end106and lip112of a similar casing with minimal clearance.

In the preferred embodiment, the length of the first female section130is sufficient to allow the first female section130to act as an alignment sleeve for the male end106of a similar casing. However, it is anticipated that the first female section130could be of varying lengths or have no length and only be the mouth of the female end108. Also, in the preferred embodiment, the thickness of the wall of the first female section130is substantially equal to the thickness of the wall of the main length107, such that, the outer diameter134of the first female section130is also widened. However, it is anticipated that the thickness of the first female section130and thus, its outer diameter134could vary.

Still referring toFIGS. 2,3, and4, a second female section136extends inwardly from the first female section130. The second female section136has a tapering interior diameter137which narrows from the widened interior diameter132of the first female section130to a diameter which is less than the outer diameter of the lip112at the leading edge of the male end106. In the preferred embodiment, the thickness of the wall of the second female section136is substantially equal to the thickness of the wall of the main length107, such that, the outer diameter of the second female section136also tapers and narrows. However, it is anticipated that the thickness of the second female section136and thus, its outer diameter could vary.

Still referring toFIGS. 2,3, and4, a third female section140extends inwardly from the inner most end of the second female section136and has an interior diameter142which is substantially equal to the narrowest diameter of the tapering second female section136. In the preferred embodiment, the thickness of the wall of the third female section140is substantially equal to the thickness of the wall of the main length107. However, it is anticipated that the thickness of the third female section140, and thus, its outer diameter could vary.

Referring toFIGS. 3,4, and5, a circumferential groove144is cut into the interior surface of the female end108. The groove144is of sufficient width and depth to receive the lip112at the leading edge of the male end106of a similar casing. In the preferred embodiment, the groove is positioned in the third female section140. However, it is anticipated that the groove could also be positioned in the second female section136.

As shown inFIGS. 2,3,4, and5, an O-ring124is placed around the circumference of and engages the male end106of the casing102. In the preferred embodiment, the O-ring rests within a groove125cut into the outer surface of the male end106around its circumference. However, it is anticipated that other placements of the O-ring could be utilized.

FIG. 4depicts the general placement of a male end106and a female end108prior to insertion of male end106into female end108.FIG. 5is a cross-section view of the water well casing102with the male end106fully inserted into the female end108.

Referring toFIGS. 4 and 5, in the preferred embodiment, as the male end106of casing102is inserted into the female end108, the outer diameter of the lip112at the male end106makes contact with the interior surface146of the tapered second female section136. As the male end106is further inserted, the interior surface146of the second female section136exerts a compressive force onto the lip112resulting in compression of the male end106with narrowing of the slots122. At full insertion of the male end106into the female end108, the lip112reaches groove144of female end108, the compressive force on the lip112is released and the lip112expands into groove144. The squared shoulder121engages the front wall148of the groove144locking the male end106of the lip112into female end108. The engagement of the squared shoulder121of the lip112with the front wall148of the groove144resists pulling forces and prevents the connected casing102from being pulled apart under the hanging loads which exist when the casing102is placed in the water well. In addition, at full insertion, the O-ring124on male end106makes contact with the interior surface of female end108, creating a seal.