Device and method for repairing pipe leakage

Abstract

A device for repairing pipe leakage takes the form of a short section of PVC pipe with fittings. The pipe is ideally a 1′-2′ section fashioned into a U-bend with a substantially semi-circular bend and two arms, and the fittings take the form of an elbow joint glued onto each arm. The arms are ideally offset up to 5° from parallel. A method of repairing cracked PVC piping using the device involves cutting out a 4″-6″ section of piping, gluing the exposed ends of the broken piping as well as the elbow joints, squeezing the U-bend, positioning the squeezed device into the gap in broken piping, and releasing the U-bend to fit the elbow joints over the exposed ends of broken piping. The device has no vulnerable moving parts or O-rings, and it obviates the need to remove entire pipes.

Claims

1. A plumbing repair device, comprising a U-bend of PVC pipe, comprising a first arm, a second arm substantially parallel to the first arm, and a substantially semi-circular bend connecting the first arm to the second arm; an end on each arm; the entire device lying in an imaginary plane, said plane containing an imaginary midline parallel to and equidistant from the first and second arms, and said plane also containing an imaginary axis perpendicular to the midline; a first elbow joint and a second elbow joint, each elbow joint having a proximal end and a distal end, each distal end having a center; the proximal end of the first elbow joint being secured to the end of the first arm, and the proximal end of the second elbow joint secured to the end of the second arm; such that the elbow joints are oriented with their distal ends facing in opposite directions, with the imaginary axis passing through the centers of the two distal ends; said device having a spring constant between 30 pounds per inch and 50 pounds per inch, as applied to a squeeze force displacing the ends of the arms along the imaginary axis toward the imaginary midline.

2. The device of claim 1, wherein the second arm is offset from parallel to the first arm with an offset angle not exceeding 5°.

3. The device of claim 2, wherein the second arm is offset from parallel to the first arm with an offset angle exceeding 3°.

4. A plumbing repair device, comprising a U-bend of PVC pipe between ½″ and 1″ in diameter, comprising a first arm, a second arm substantially parallel to the first arm, and a substantially semi-circular bend connecting the first arm to the second arm; each arm having arm length between 3″ and 9″; said bend having bend radius between 2″ and 3″; an end on each arm; the entire device lying in an imaginary plane, said plane containing an imaginary midline parallel to and equidistant from the first and second arms, and said plane also containing an imaginary axis perpendicular to the midline; a first elbow joint and a second elbow joint, each elbow joint having a proximal end and a distal end, each distal end having a center; the proximal end of the first elbow joint being secured to the end of the first arm, and the proximal end of the second elbow joint secured to the end of the second arm; such that the elbow joints are oriented with their distal ends facing in opposite directions, with the imaginary axis passing through the centers of the two distal ends.

5. The device of claim 4, wherein the pipe has a diameter between ⅜″ and ⅝″; the arm length is between 4″ and 5″; and the bend radius is between 2″ and 2.5″.

6. The device of claim 5, wherein the second arm is offset from parallel to the first arm with an offset angle not exceeding 5°.

7. The device of claim 6, wherein the second arm is offset from parallel to the first arm with an offset angle exceeding 3°.

8. The device of claim 4, wherein the pipe has a diameter between ⅝″ and ⅞″; the arm length is between 5.5″ and 6.5″; and the bend radius is between 2.25″ and 2.75″.

9. The device of claim 8, wherein the second arm is offset from parallel to the first arm with an offset angle not exceeding 5°.

10. The device of claim 9, wherein the second arm is offset from parallel to the first arm with an offset angle exceeding 3°.

11. The device of claim 4, wherein the pipe has a diameter between ⅞″ and 9/8″; the arm length is between 7″ and 8″; and the bend radius is between 2.25″ and 2.75″.

12. The device of claim 11, wherein the second arm is offset from parallel to the first arm with an offset angle not exceeding 5°.

13. The device of claim 12, wherein the second arm is offset from parallel to the first arm with an offset angle exceeding 3°.

14. The device of claim 4, wherein the second arm is offset from parallel to the first arm with an offset angle not exceeding 5°.

15. The device of claim 14, wherein the second arm is offset from parallel to the first arm with an offset angle exceeding 3°.

Description

5. BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a front view of the device showing its main features and geometry.

(2) FIG. 2 is a side view of the device.

(3) FIG. 3 is a perspective view of the device.

(4) FIG. 4 illustrates the method of repairing pipe using the device.

(5) FIG. 5 shows the device in place as a repair unit on PVC piping.

(6) FIG. 6 is a stylized illustration of the device used to illustrate the angular offset of the arms.

6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) The article of manufacture 1 includes a segment of PVC pipe 11, ideally ½″-1″ in diameter and approximately 1′ to 2′ long. The pipe is configured in a “U” shape, comprising two arms 111 and a semi-circular bend 112 with a bend radius 1121. The arms are parallel, and they have an equal arm length 1111. Each arm has an end 1112 (not seen in the figures).

(8) To refer to the geometry of article 1, we take note of the imaginary plane 12 containing the “U”, and the imaginary midline 121 that lies in the imaginary plane and is equidistant from the two arms.

(9) The device further comprises two elbow joints 13, preferably 90° joints. Each elbow joint has a proximal end 131 and a distal end 132. Each distal end is circular and has a center 1321. The proximal end of each elbow joint is affixed to the end 1112 of one arm, ideally with plumbing adhesive. The distal ends of the elbow joints open in opposite directions from one another. An imaginary axis 122 runs through both centers 1321 of the distal ends 132. This common axis 122 lies in the aforementioned imaginary plane 12 and is perpendicular to the arms and to the imaginary midline 121. In an alternative embodiment, the elbow joints are modified with elbow angle between 85° and 95°, as seen in FIGS. 1 and 3.

(10) To assemble the article, a straight segment of PVC pipe 11 is first heated to a temperature ideally in the range of 275° to 325° F. Heating the plastic makes it supple. Bending the pipe without the assistance of further tools would create unwanted kinks and weaknesses. To preserve structural integrity, a mandrel is inserted through the segment of pipe while it is hot but still straight. The mandrel is bent in the desired configuration. That is, at the midpoint between the two ends 1112 of the pipe, the mandrel is bent into a semicircular bend 112 with the desired bend radius 1121. The rest of the mandrel remains straight, thus forming the aforementioned arms 111 as described. The pipe is allowed to cool, harden, and reset in the bent configuration before the mandrel is removed. Finally, elbow joints 13 are glued onto the end of each arm, in the configuration described above.

(11) The article is ideal for repairing a small fracture in PVC piping by the following method. The broken pipe 2 is cut to either side of the fracture, at a distance from the fracture slightly larger than the bend radius 1121. The cut segment of broken pipe 2 is removed, leaving two exposed ends 21. Glue is applied to the exposed ends of the broken pipe and to the interior of the elbow joints 13 on the invention.

(12) The article is squeezed with squeeze force 3 so that the two elbow joints 13 are displaced toward each other along their common axis 122, as shown in FIG. 4. The article is then positioned in the gap between the exposed ends of broken pipe 21 so that the imaginary axis 122 aligns with the length of broken pipe 2. There will momentarily be a displacement gap 4 between each exposed end of broken pipe 21 and the distal end of an elbow joint 132. The squeeze force 3 is then relaxed so that the arms 111 spring back into equilibrium position. This action will close the displacement gaps 4 and bring the elbow joints 13 into position to fit over the exposed ends of broken pipe 21. When the glue sets, the broken pipe 2 and this article 1 will form one continuous pipe system as seen in FIG. 5. The new system will be at least as strong as the original pipe.

Best Mode Parameters

(13) In our experience, we find that the invention works best when the squeeze force 3 due to an average one-handed human grip as illustrated in FIG. 4 will displace the elbow joints about 1.5″ toward each other, i.e. ¾″ for each displacement gap 4. A typical squeeze force for a grip as shown in FIG. 4 is 60-80 pounds, i.e. 30-40 pounds on each arm of the device. These parameters indicate that the device should have a spring constant of roughly 40-50 lb/in.

(14) The spring constant is a function of the pipe diameter, the arm length 1111, and the bend radius 1121. Our experimentation has shown that the spring constant varies much more with arm length than with bend radius. Therefore, the bend radius is engineered to meet other concerns as well, such as fitting the human hand and accommodating a reasonable length of pipe removal.

(15) In its best mode, the uniqueness of the device is its 40-50 pound per inch restorative force. Such force allows glue joint adhesion to take place without the need for steady and constant hand pressure. It also allows for one-handed installation in what could be considered difficult locations.

(16) In order to achieve this optimal spring constant, experimentation has shown that the ideal dimensions for Schedule 40 pipe are the following.

(17) For ½″ pipe, the optimal bend radius is approximately 2.25″ and the optimal arm length is approximately 4.5″.

(18) For ¾″ pipe, the optimal bend radius is approximately 2.5″ and the optimal arm length is approximately 6″.

(19) For 1″ pipe, the optimal bend radius is approximately 2.5″ and the optimal arm length is approximately 7.5″.

(20) The squeeze force displaces the arms in terms of angle as well as distance. The squeeze parameters discussed above will displace the arms roughly 5° from their rest position. This causes misalignment in the elbow joints so that they do not both line up perfectly with the broken pipe. To compensate, we provide an alternative embodiment with an arm offset angle 1113, seen in FIG. 6. The arm offset angle is defined by the angle by which one arm 111 deviates from the parallel to the other arm. The arm offset angle 1113 is ideally in the range of 0-5°; greater deviation makes the product look malformed and is not necessary for typical squeeze forces.