Coupling tool and method of use

A slip coupling tool having an interior surface sized for receiving a pipe. The coupling tool includes a semi-annular collar sized to engage an exterior surface of the pipe. The collar extends to a rearward end face sized and shaped for aligning with an end of the slip coupling when the collar receives the pipe and the inner surface of the collar engages an exterior surface of the pipe. The slip coupling tool includes a striking plate extending outward from the collar. The striking plate has an impact surface spaced from the collar for impacting the coupling tool to drive the slip coupling into position along the pipe. The slip coupling tool includes a handle extending outward from the collar for manipulating the tool into position while impacting the impact surface of the striking plate to drive the slip coupling into position along the pipe.

BACKGROUND

The present invention generally relates to pipe couplings, and more particularly, to a coupling tool for assembling slip couplings on pipes and methods of using the tool.

Lateral sewer lines extend from residential and commercial buildings to larger main sewer lines that deliver waste to processing plants where waste is treated and solids are removed before processed water is returned to a natural body of water such as a river, lake, or ocean. Lateral sewer lines become damaged, for example from tree root ingress, cycles of freezing and thawing, and from being struck by tools and equipment. In the past, damaged lateral sewer lines were repaired by excavating to expose a damaged section, removing the damaged section, fitting a replacement section in place, and coupling each end of the replacement section to a corresponding adjacent end of the original undamaged sewer line. Conventional couplings such as Fernco® pipe couplings (designated by the letter F inFIG.1) were used to couple each end of the replacement section to the corresponding adjacent end of the undamaged line. Fernco is a U.S. federally registered trademark of Fernco, Inc. of Davidson, Mich. Such couplings are compliant, allowing for misalignment and movement. An example of a repair made with these conventional couplings is shown inFIG.1. Over time these couplings deteriorate, allowing waste to leak. To alleviate leakage from deterioration, some building codes require the coupling to be encased in cement. Not only is the per-unit price of a conventional coupling expensive, but the labor and materials for encasing the coupling in cement also adds to their cost.

Conventional slip couplings can be used in place of the compliant Fernco® pipe couplings. To install a slip coupling, an end of the first pipe is coated with adhesive and the slip coupling is inserted over the coated end. The end of the first pipe having the slip coupling is aligned with the end of the second pipe. The end of the second pipe is coated with adhesive before the slip coupling is driven toward the coated end of the second pipe. The slip coupling is centered on the abutted ends of the first and second pipes. Because the slip coupling has a far greater life than the compliant conventional couplings, building codes generally do not require the slip coupling to be encased in cement. Further, slip couplings are substantially less expensive than Fernco® pipe couplings. Thus, there are substantial advantages to using slip couplings. However, driving the couplings onto the end of the first pipe and onto the end of the second pipe frequently requires the coupling to be tapped into place with a hammer. To avoid damaging the slip coupling or the pipes, the worker may use a piece of scrap wood, positioning the wood adjacent the coupling and striking the wood with the hammer. Over time, the scrap wood chips and splits, requiring replacement. Further, depending upon the size and shape of the wood, the hammer may contact the pipe or coupling, causing damage and requiring removal and further repair. Thus, there is a need for a tool to eliminate or reduce the various disadvantages of conventional tools and methods described above.

SUMMARY

In one aspect, the present disclosure includes a slip coupling tool for use when positioning a tubular slip coupling on pipe having an exterior surface. The slip coupling has an interior surface sized for receiving the pipe extending between opposite ends. The coupling tool comprises a semi-annular collar having a circular inner surface sized to engage the exterior surface of the pipe. The inner surface extends between a forward end face and a rearward end face opposite the forward end face. The rearward end face is sized and shaped for aligning with a first end of the opposite ends of the slip coupling when the interior surface of the slip coupling receives the pipe and the inner surface of the collar engages the exterior surface of the pipe. The slip coupling tool also includes a striking plate extending outward from the forward end face of the collar. The striking plate has an impact surface spaced from the collar for impacting the coupling tool to drive the slip coupling into a predetermined position along the pipe. In addition, the slip coupling tool comprises a handle extending outward from the collar for engaging the inner surface of the collar with the exterior surface of the pipe and aligning the rearward end face of the collar with the first end of the slip coupling while impacting the impact surface of the striking plate to drive the slip coupling into the predetermined position along the pipe.

In another aspect, the present disclosure includes a method of repairing a pipe using a slip coupling tool. The method includes removing a damaged section of pipe so opposing ends of original pipe are axially separated by a distance and selecting a replacement pipe section of a length generally equal to the distance between the opposing ends of original pipe. The replacement section is offset from a first end of the opposing ends of original pipe and an area of the replacement pipe section is coated with an adhesive system. An area of an interior of a slip coupling is coated with the adhesive system before slipping the coated slip coupling over the coated area of the replacement pipe section. The replacement pipe section is aligned adjacent the first end of the opposing ends of original pipe. An area of the first end of the opposing ends of original pipe is coated with an adhesive system and a pipe coupling tool is positioned adjacent the slip coupling before impacting the slip coupling to drive the coupling over the first end of said opposing ends of original pipe.

Other aspects of the present invention will be apparent in view of the following description and claims.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring toFIGS.2and3, a slip coupling tool is designated in its entirety by the reference number20. The tool20generally comprises a head (generally designated by22) and a handle (generally designated by24). The head22includes a yoke-shaped striking plate30, a semi-annular collar32, and triangular gussets34. As used in this document, the prefix “semi-” is intended to include half or less. For example, semi-circular is intended to mean half or a lesser portion of a circle.

As illustrated inFIGS.3-5, the collar32has a semi-circular inner surface36sized and shaped to engage the exterior surface of a pipe P1with which the tool20is intended to be used. In some examples, the inner surface36is sized and shaped to engage the exterior surface of a pipe having a conventional standard diameter. Further, the collar32has a rearward end face38sized and shaped to be aligned with a corresponding end of the slip coupling C when the interior surface of the slip coupling receives the pipe P1and engages the exterior surface of the pipe. Although not visible in the drawings, those skilled in the art will appreciate that the collar36has a forward end face opposite the rearward end face38. When the inner surface36of the collar32receives the pipe P1and aligns the end face38with the end of the slip coupling C, so impact delivered to the head22is precisely conveyed to the slip coupling.

As shown inFIGS.2-6, the striking plate30extending outward from a semi-circular inner margin corresponding to and overlapping the forward end face of the collar32at an inner end40of the plate to an outer end42. An impact surface44adjacent the outer end42is the spaced from the collar32by a distance to reduce a possibility of unintentionally impacting the pipe when striking the impact surface to drive the slip coupling C into a predetermined position along the pipe P. Further, the striking plate30is sized and shaped to allow the worker to forcefully strike the plate with a hammer while allowing sufficient clearance between the hammer and the pipe or coupling to reduce a likelihood of striking the pipe or coupling with the hammer. In some examples, the impact surface44is spaced from the collar32by a distance greater than two inches, and in other examples by a distance of three, four, or more inches. The inner end40of the impact plate30includes a semi-annular flange46extending outward from the forward end face of the collar32. The flange46includes the semi-circular inner margin aligned with the forward end face of the collar32so the plate30transmits impact loads to the collar when the impact surface44of the coupling tool20is struck (e.g., by a hammer H) to drive the slip coupling C into the predetermined position along the pipe. Gussets34extend between the striking plate30and the collar32to strengthen the flange46against bending when transmitting impacts from the striking plate to the collar. Although the components forming the head22of the tool29(i.e., the striking plate30, collar32, and gussets34) may be made from other materials, the components of the illustrated tool20are made from quarter-inch steel plate cut and formed to shape using conventional methods. The components are welded using conventional techniques in the configuration shown inFIGS.2-4.

The handle24includes an extension50and a grip52. Although the extension may be formed from other materials, the extension50of the example tool20is formed from 1 inch square steel tubing abutting the striking plate30opposite the impact surface44. The handle24is welded to the striking plate30and collar32as shown. The extension50is of a length sufficient to separate the worker's hand holding the grip52from the impact surface44of the striking plate30to reduce a possibility of contacting the worker's hand while impacting the impact surface. Further, the extension50is sized to permit a work to manipulate the tool20. In the illustrated example, the grip42is made from a suitable synthetic rubber material to dampen forces transmitted through the handle50when the impact surface44is struck with the hammer. The illustrated grip42is available from Emgo International Ltd. of Austell, Ga.

In use, the worker grasps the grip52of the tool20and positions the inner surface36of the collar32against a first pipe P1so the rearward end face38of the collar is adjacent the slip coupling C as shown inFIGS.5and6. The worker then taps the striking plate30with a hammer H to move the coupling over the adjacent end of the second pipe P2. Although a gap is shown inFIG.6between the abutted ends of the first pipe P1and the second pipe P2, in practice the gap is minimized.

In a first detailed example, a worker locates a broken section of pipe such as by using a conventional push video camera manipulated through the interior of the lateral sewer line. The worker excavates earth above and around the broken pipe. In some examples, the worker uses a mini excavator and shovel to excavate the earth. Once the broken section is exposed, the worker cuts the exposed pipe at opposite ends of the broken section and removes the broken section. In some examples, the work uses a reciprocating saw to cut the pipe. A suitable replacement section of pipe is cut to length and trial fit in position between the cut ends of the original pipe.

As shown inFIG.7a, a replacement section of SD40PVC pipe is designated P1and an original section of schedule40pipe is designated P2. The replacement section P1is laterally offset from the original pipe section P2as shown inFIG.7b. An area Al of a butt end of the replacement pipe section P1is treated with an adhesive system. For example, area Al may be coated with a clear primer available from Hercules Industries, Inc. of Denver, Colo., and then coated with clear PVC cement, which is also available from Hercules. Although other applicators may be used, in the illustrated example the primer and cement are applied with a brush. The interior of a slip coupling C is similarly treated before the coupling is slid into position over the coated butt end of the replacement pipe section P1as illustrated inFIG.7c. The striking plate30of the tool20may be used to tap the slip coupling C into this position over the coated butt end of the replacement pipe section P1. Once the coupling C is in the position shown inFIG.7c, the replacement pipe section P1is repositioned so the butt ends of the replacement pipe section P1and the original pipe section P2are axially aligned and adjacent one another as shown inFIG.7d. An area A2of the butt end of the original pipe section P2is treated with the adhesive system. Finally, the tool20is positioned as inFIG.6, and the slip coupling C is driven into the position shown inFIG.7eso the abutted ends of the replacement pipe section P1and the original pipe section P2are centered along the slip coupling C. After repair with the replacement pipe section P1, the repaired pipe may be buried using conventional methods.

FIG.8illustrates a second detailed example in which the damaged section is located and excavated as in the previous example. A damaged section of pipe (not shown) is removed from a lateral sewer line leaving spaced sewer pipe sections L1and L2. In this example, the lateral sewer line is SDR35PVC D3034pipe. Conventional adapter unions U1and U2are bonded to the ends of the sewer pipe sections L1and L2as shown. Appropriate lengths of SD40PVC pipe P1and P2are cut using conventional techniques and bonded to the unions U1and U2. The joint J between the sections of SD40PVC pipe P1and P2is joined as described in the previous example.

The tools20may be sized so that the collar32accepts different nominal pipe sizes. For example, a set of tools such as shown inFIG.9may consist of tools adapted for use with pipes having nominal diameters of 1.25, 1.50, 2, 3, 4, 5, and 6 inches. Other sizes such as 8, 10, and 12 inch diameters or larger are also envisioned.