Abstract:
Pipe fittings, used in joining abutting ends of two pipe sections, comprise a pair of semi-cylindrical members that are adapted to fit around and engage the periphery of opposed ends of the two abutting ends of the pipe sections. Longitudinal edges of the two semi-cylindrical members are formed so as to mate with one another to form a mechanical means of locking the semi-cylindrical members together in tight engagement with the ends of the pipes. Each of the semicylindrical members has a seal mechanism formed of a resilient, elastomeric material which forms a mechanical, water-tight seal between the mutually respective pair of semi-cylindrical members as well as the opposite ends of the pipes to which the pair of semi-cylindrical members have been attached.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the priority from U.S. Provisional Patent Application No. 60/785,199 filed on Mar. 21, 2006. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to fittings for joining sections of pipe, and more particularly to such fittings for repairing leaks in existing piping or joining an additional pipe line to existing pipe where the existing pipe is relatively inaccessible and cannot be removed and replaced without substantial difficulty. 
   2. State of the Art Prior to the Invention 
   Plastic pipes have become widely used in sprinkler systems because of their low cost and ease of installation and repair. Such pipes, commonly referred to as PVC pipes because of their typical polyvinyl chloride composition, may be joined without threading by applying an adhesive such as a solvent cement type to the ends of the pipes and slipping a smooth-bored fitting over the ends of the pipes. 
   When a break occurs in an underground piping system made from PVC piping, it can be repaired by digging away the dirt over the break and then cutting out a small section of pipe that contains the break. A coupling is then placed on the two opposed ends of the cut pipe. A conventional coupling is a simply rigid, hollow, cylindrical section that has an internal diameter that fits snugly over the external diameter of the pipe. Adhesive is applied to the inside surface of one end of the coupling and around the external surface of one end of the pipe. Sliding the coupling over the end of the pipe is done rapidly and effortlessly. Adhesive is now applied to the internal surface of the second end of the coupling and the end of the second pipe. The end of the second pipe must now be slid into the second end of the coupling and great difficultly is encountered in accomplishing this step. The two ends of the pipe are bent as far as possible away from their center lines so that the gap between the second end of the coupling and the end of the second pipe is increased sufficiently to allow insertion of the end of the second pipe into the second end of the coupling and forcing the pipes back into axial alignment which also forces the end of the second pipe into the second end of the coupling. The dirt along a relatively long section on each side of the pipe where the coupling is being installed must be removed to permit sufficient bending of the pipe in existing underground piping systems. This requires considerable labor in both digging away of the dirt as well as replacement of the dirt once the repair is made. 
   In those situations where a new pipe line is desired to be added to an existing pipe line, dirt must be removed to expose the area of the existing piping to which the second pipe line is to be connected. The existing pipe is cut and a small section removed so that a fitting in the form of a tee or a wye can be connected in line in the existing pipe. These fittings, the tee and the wye, have two ends very similar to the ends of the coupling which was described above, and the two ends of the fittings must be installed in the existing pipe line in the same manner as described above for installing a coupling in the existing pipe line. 
   It has been acknowledged in the prior art that it would be desirable to provide a fitting that could be installed in an existing piping system without requiring bending of the two pipes to which the fitting is to be connected. The disclosure of a series of inventions is shown in U.S. Pat. Nos. 3,971,574; 4,103,943; 4,109,944; and 4,429,907 wherein a coupling is formed of two semi-cylindrical members which are arranged to enclose and encapsulate the opposite ends of two pipes that are to be connected for fluid flow through the connected pipes. The two semi-cylindrical members are made of plastic and designed to be adhesively bonded to each other and to the two ends of the pipes by a suitable cement so as to provide a water-tight seal. The use of cement to bond the semi-cylindrical members is a very messy procedure, and becomes even more complicated by the required effort of maintaining the semi-cylindrical members in constant, firm contact with the two ends of the pipe until the cement has set sufficiently to hold the assembly in its proper place. The series of developments disclosed in the above-mentioned U.S. Patents are directed to various means of holding the semi-cylindrical members in their proper positions as the cement sets. The use of a liquid cement is still messy, and it would clearly be desirable to have a system in which a liquid cement is not necessary in forming a liquid-tight seal between the two semi-cylindrical members and the two ends of the pipes. 
   OBJECTIVE OF THE PRESENT INVENTION 
   The principal object of the present invention is to develop a system for connecting the opposed ends of two pipes that are aligned with each other using two semi-cylindrical members that fit snugly around the opposed ends of the two pipes and span between the opposed ends of the two pipes, with the semi-cylindrical members being provided with a mechanical means of making a fluid tight seal between themselves and the opposed ends of the two pipes without using any cement of any kind. 
   SUMMARY OF THE INVENTION 
   The objective of the present invention is accomplished by providing a system for connecting the opposed ends of two pipes that are aligned with an improved fitting comprising two complimentary, semi-cylindrical members that are adapted to be brought together and mechanically joined to each other to form a resulting cylindrical fitting. The cylindrical fitting has opposite, otherwise open ends that envelope the respective opposite ends of two pipes that are to be connected together using the fitting. Each semi-cylindrical member has a resilient gasket member associated therewith. Each gasket member has two arcuate elements in which the arcuate elements have the shape of a half circle. The two arcuate elements are received into mutually respective arcuate grooves formed in the internal surface of the respective semi-cylindrical member, with the arcuate grooves forming substantially a half circle that extends from one longitudinal side to the other longitudinal side of the semi-cylindrical member. The annular grooves are spaced apart from each other along the longitudinal length of the semi-cylindrical members. Each resilient gasket member has two opposite, longitudinal sides that span between respective distal ends of the two arcuate elements of the gasket member. The opposite ends of the longitudinal sides of the gasket member are molded integrally with their respective distal ends of the pair of arcuate elements so that the resilient gasket member is a continuous, unitary member. The resilient gasket member is molded from a resilient elasomeric material. 
   The arcuate elements of each of the gasket members are received in the arcuate grooves of their respective semi- cylindrical member, and the connecting longitudinal sides of each of the gasket members lie along respective longitudinal sides of the respective semi-cylindrical member. When the two semi-cylindrical members are joined together around the ends of two pipes that are to be joined, the arcuate elements of the associated gasket members make a mechanical, fluid-tight seal between the respective ends of the pipes and the semi-cylindrical members, and the engagement between the longitudinal sides of the two associated gasket members with each other make a mechanical fluid-tight seal along the longitudinal sides of the two semi-cylindrical members of the resulting fitting. Accordingly, the fitting, including the two gasket members thereof, achieves a mechanical, fluid-tight seal without use of an adhesive or cement. 
   The invention will be described in more particularity with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a pictorial view of one of the semi-circular members of the present invention which can be used with a second identical member to make a fitting for connecting abutting ends of two pipes, with the gasket member which is associated with the semi-circular member shown in exploded view; 
       FIG. 2  is an exploded side elevation view showing two of the semi-circular members and their associated gasket members ready to be mechanically connected to each other over the abutting ends of two pipes; 
       FIG. 3  is a cross section of the semi-circular member of  FIG. 1  taken along line  3 - 3  of  FIG. 1  with the gasket member in its proper operational position; 
       FIG. 4  is a cross section of the semi-circular member of  FIG. 1  taken along line  4 - 4  of  FIG. 1  with the gasket member in its proper operational position; and 
       FIG. 5  is a cross section of the two semi-circular members and their associated gasket members of  FIG. 2  taken along line  5 - 5  of  FIG. 2 , with semi-circular members and the gasket members shown in their proper operational position; and 
       FIG. 6  is a side elevation view of a fitting in accordance with the invention showing a tee fitting that is joining the end of an additional pipe to an established pipe that has been breached to allow insertion of the fitting between two opposed ends of the breached pipe. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In accordance with the present invention, there is provided an improved fitting for connecting the opposed ends of two pipes that are axially aligned and in close proximity to each other. The improved fitting comprises two complimentary, semi-cylindrical members that are adapted to be brought together and mechanically joined to each other to form a resulting cylindrical fitting that envelopes the ends of the two aligned pipes. Each of the semi-cylindrical members is provided with a novel gasket member, and the gasket members of the two mechanically joined semi-cylindrical members interacts with the joined semi-cylindrical members, the two ends of the pipe that are being connected and themselves to form a fluid-tight seal between the resulting cylindrical fitting and the ends of the two pipes so that there is no need to employ adhesives or cements in accomplishing the fluid-tight seal between the fitting and the pipes. 
   One of the semi-cylindrical members  10  is shown in  FIG. 1 . The cylindrical member  10  has a semi-cylindrical sidewall  11  that has two ends  12  and two longitudinally extending side edges  13 . The cylindrical member  10  is formed of any applicable thermoplastic material, preferably polyvinylchloride. The thickness of the sidewall  11  is generally between about 2.5 and about 3.5 millimeters. The two longitudinally extending side edges  13  will of course have a thickness that is substantially the same as the thickness of the sidewall  11 . 
   A pair of arcuate, semi-circular grooves  14  are formed  10  on the inside surface of the sidewall  11 . The arcuate grooves  14  form a substantially half circle that extends from one longitudinal side edge  13  to the other longitudinal side edge  13  of the sidewall  11 . The arcuate grooves  14  are spaced apart from each other along the longitudinal length  15  of the inside surface of the sidewall  11 . The arcuate grooves  14  ( FIG. 1 ) have a width of at least about 2 to 3 millimeters, and preferably the width of the arcuate grooves  14  is between about 3 and about 10 millimeters. The longitudinal length of the sidewall  11  will be at least 20 about 35 millimeters, and preferably between about 40 and 50 millimeters, at least for the two-way coupling fitting as shown in  FIGS. 1-5 . The longitudinal length of the sidewall  11  will be longer for a tee fitting as shown in  FIG. 6  and explained in more detail hereinafter. 
   As mentioned, the arcuate grooves  14  are spaced apart from each other. Preferably, the arcuate grooves  14  will be spaced apart sufficiently such that there will be a continuous segment of the sidewall  11  between the arcuate grooves that has a length of from about 8 to about 20 millimeters for the two-way coupling fitting as shown in  FIGS. 1-5 . The longitudinal length of continuous sidewall  11  between the arcuate grooves  14  for a tee fitting as shown in  FIG. 6  will be longer than for the two-way coupling fitting as will be explained in more detail hereinafter. The arcuate grooves  14  further preferably have a depth of between about 1 and 2 millimeters. 
   A gasket member  15  is provided for each semi-circular member  10 , with the gasket member  15  being adapted to fit in the grooves  14  and along the portion of the longitudinal side edges  13  of the semi-circular member  10  extending between the grooves  14 . The gasket member  15  comprises a pair of arcuate sections  16  that are adapted to fit snugly within the grooves  14  in the sidewall  11  of the semi-cylindrical member  10 . Thus, the arcuate sections  16  have substantially the shape of a ribbon curved in a half circle. Each resilient gasket member  15  has two opposite, longitudinal sides  17  that span between respective distal ends of the two arcuate sections  16  of the gasket member  15 . As illustrated, the longitudinal sides  17  have the shape of a relatively narrow, flat ribbon whose width is no greater than about the thickness of the sidewall  11  of the semi-circular member  10 . The longitudinal sides  17  are molded integrally with the arcuate sections  16 , with the upper surface of the flat ribbon of the longitudinal sides  17  coincide with and in effect form the distal ends of the arcuate sections  16 . The resilient gasket member  15  is thus a continuous, unitary member. The resilient gasket member is molded from a resilient elastomeric material. 
   The dimensions of the gasket member  15  are such that the arcuate sections  16  thereof will fit snugly in the grooves  14 , with the sides  17  of the gasket member lying along the longitudinal side edges  13  between the grooves  14 . Thus the dimensions of the gasket member  15  depend upon the dimensions of the grooves  14  and the length of the longitudinal side edges  13  between the grooves  14 . The two independent measurements for the gasket member  14  is that the thickness of the ribbon forming the arcuate section  16  will be such that it is at least between about 0.3 and 1 millimeter larger than the depth of the grooves  14  in the sidewall  11  of the semi-circular member  10 , and the thickness of the longitudinal side edges  13  will be between about 0.75 and 2 millimeters. 
   A pair of complimentary, semi-cylindrical members  10  are adapted to be superimposed one over the other with their broad, open sides facing each other so that their respective longitudinal edges  13  abut one another so as to form a resulting cylindrical fitting having two open ends. In use, as best shown in  FIGS. 2 and 5 , the opposite, otherwise open ends of the resulting cylindrical fitting envelope the opposite ends  18  of two pipes that are to being connected together. Means are provided to mechanically join or lock the mutually respective, abutting longitudinal edges  13  of the semi-cylindrical members  10  together so that the internal cylindrical surfaces of the semi-cylindrical members  10  are held firmly in snug engagement with the outer surfaces of the ends  18  of the two pipes that are located within the resulting fitting. 
   In a preferred embodiment as illustrated in the drawings, the mechanical means of joining and locking the abutting longitudinal edges  13  of the semi-cylindrical members  10  together comprises a ledge  19  projecting outwardly adjacent to the longitudinal edges  13  on each of the semi-cylindrical members  10 . The ledge  19  extends essentially along the entire length of each of the longitudinal edges  13  of the semi-cylindrical member  10  from one end to the other end thereof. A sharp outer edge  20  extends along the length of the ledge  19 . An upstanding sidewall  21  projects upwardly from the ledge  19 , with the upstanding sidewall  21  being positioned so as to extend from one end of the semi-cylindrical member  10  inwardly to a position that is no more than one-half the distance between the opposite ends of the semi-cylindrical member  10 . The upper side of the sidewall  21  has a sidewall ledge  22  integrally formed therewith that extends inwardly from the sidewall  21  and ends in a sharp inner edge  23 . When two complimentary semi-cylindrical members  10  are brought into their working, abutting positions about the opposite ends  18  of two pipes, as shown in  FIG. 5 , the sidewalls  21  of each of the semi-cylindrical members extend over the mutually respective ledges  19 , and the sidewalls  21  can be forced over the ledges  19  until the sharp inner edge  23  of the sidewall ledge  22  snaps over and locks with the sharp outer edge  20 . 
   To facilitate the forcing of the sharp outer and inner edges  20  and  23  over each other and into locking engagement, two things can be done. First the ledges  19  and  22  which form the sharp edges  20  and  23  can be tapered so that the taper of ledges  19  are complimentary with the taper of ledges  22  to facilitate the edges sliding over each other. Second, lugs  24  can be positioned so as to extend outwardly from the outer surface of the semi-cylindrical members  10  immediately below the portion of the side ledges  19  which do not have a sidewall ledge  22  extending therefrom. When the two complimentary semi-cylindrical members  10  are brought into working, abutting arrangement, the lugs  24  will be positioned directly opposite mutually respective sidewall ledges  22 , and a gripping tool such as a pair of players can be used to grip the mutually respective lugs  24  and sidewall ledges  22  to force them toward each other so as to force the sharp outer and inner edges  20  and  23  over each other and into locking engagement to thereby lock the complimentary semi-cylindrical members  10  together. 
   When the complimentary semi-cylindrical members  10  are snapped and locked together around the opposite ends  18  of two pipes, the arcuate sections  16  of the gasket members  15  are forced into fluid-tight engagement with the surface of the respective ends  18  of the pipes, and the mutually respective sides  17  of the gasket members  15  are forced into fluid-tight engagement with each other along the side edges of the fitting between the arcuate sections  16 . Thus, a complete, fluid-tight seal is formed between the resulting fitting, i.e., the complimentary, interlocked semi-cylindrical members  10  and the ends  18  of the two pipes. 
   The semi-cylindrical members  10  can be modified slightly from those of the above description so that the resulting fitting is a tee which allows an additional pipe line to be added when desired to the two ends of the existing pipe that are joined by the tee fitting. As shown in  FIG. 6 , the semi-cylindrical members  10  are essentially the same as previously described herein with two modifications. First, one of the semi-cylindrical sections  10  has an opening in it and a hollow cylinder  25  extends from that opening. The cylinder  25  opens at one end into the opening in the semi-cylindrical section  10 , and the other end of the cylinder  25  is open and adapted to have the end of another pipe  26  telescopically received therein. The end of the other pipe  26  can be sealed to the cylinder  25  by use of a solvent cement as is conventional in the art. 
   The second modification to the semi-cylindrical members  10  of  FIG. 6  is that the members  10  are somewhat longer in length than the coupling members described above with respect to  FIGS. 1-5 . The additional length is provided to allow the addition of the cylinder  25  to the fitting as shown in  FIG. 6 . The cylinder  25  is located, of course, in the length of the semi-cylindrical member  10  which is between the grooves  14  which are identical to those described previously with respect to FIGS  1 - 5 . Because of the increased distance between the grooves  14  in the fitting forming the tee of  FIG. 6 , the length of the sides  17  of the gasket member  15  will also be increased as compared to the gasket members  15  of the coupling fitting shown in  FIGS. 1-5  and described hereinbefore. 
   It should be recognized that the modification shown in  FIG. 6  could also be arranged so as to have the fitting being made of two half pieces in which the division between the half pieces falls on a central plane that passes through the center axes of all three of the openings for the pipes. In such a case, the section of the fitting which will receive the third pipe has a semicircular groove similar to the grooves  14  shown in the embodiments illustrated in the drawings. The gasket is also modified so that it includes a third semi-circular ribbon section similar to the sections  16  shown in the embodiments illustrated in the drawings. One of the sides of the gasket will join the semi-circular ribbon sections in an ell-shape so as to join the left hand ribbon section on the first pipe to the center ribbon section on the third pipe and then join the right hand ribbon section on the second pipe to the center ribbon section on the third pipe. The section of the fitting which will receive the third pipe will have longitudinal edges, ledges with sharp edges, upstanding sidewalls, sidewall edges, sharp inner edges and lugs similar to the longitudinal edges  13 , ledges  19  with sharp edges  20 , upstanding sidewalls  21 , sharp inner edges  23  and lugs  24  shown in the embodiments illustrated in the drawings.