Abstract:
An O-ring has a flange which includes a plurality of slots, such that, when inserted into an annular groove of a pipe fitting before crimping, the slots allow the flow of fluid therethrough, such that an installation would not pass pressure tests until such time as a proper crimp has been made. Such a design allows the use of conventional push-on pipe connections by utilizing a unique O-ring seal which works in conjunction with standard push-on crimp-type pipe fittings and conventional crimping tools for subsequently sealing the connection. The O-ring is either circular or elliptical in cross section and the slots define equally spaced annular segments.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119(e) and the benefit of U.S. Provisional Application No. 61/085,560 entitled CRIMP EVIDENT SEAL, filed on Aug. 1, 2008, by Scott Lee Spence, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to plumbing fittings and particularly to seals for crimp connections between fittings. 
         [0003]    In recent years, crimp-on connections have replaced the typical solder connection in copper and other metallic plumbing systems used in homes and industrial applications. Typically, the female pipe fitting will include an annular groove into which an O-ring is positioned and a male fitting inserted through the O-ring and the annular groove subsequently crimped to provide a tight seal. When numerous such connections are made in a plumbing system, particularly in large commercial installations, not infrequently crimps are missed. Frequently, O-ring seals which have not been crimped will initially pass pressure tests but, over time, will leak if the junction is not properly crimped. 
         [0004]    There is a need, therefore, for a system which will purposely leak at a connection which has been made but not properly crimped. There have been several attempts at solving this problems, including, for example, providing frangible bands around crimp fittings which, until crimped, remain in place but, once crimped, the typically plastic ring fractures and reveals the fact that the crimp has been made. Some attempts have been made also to provide specialized O-ring designs which purposely allow leakage until such time as a proper crimp has been made. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention solves the problem with improperly crimped connections by providing, in one embodiment, a ring-type seal, such as an O-ring, having a flange which includes a plurality of slots, such that, when inserted into an annular groove of a pipe fitting before crimping, the slots allow the flow of fluid therethrough, such that an installation will not pass pressure tests until such time as a proper crimp has been made. Such a design allows the use of conventional push-on copper pipe connections by utilizing a unique O-ring seal which works in conjunction with standard push-on crimp-type pipe fittings and conventional crimping tools for subsequently sealing the connection. Also, the O-ring, which is seated in an annular groove of a fitting, will rotate about its annular axis when engaged by a pipe or another fitting being inserted into a fitting. This assures that any burrs on the end of the pipe, if scarring the O-ring during insertion, such a blemish will be rotated out of the sealing surfaces between the pipe and fitting. 
         [0006]    Ring seals of one embodiment of the present invention comprise a generally annular body having a generally circular or elliptical cross section and integrally including a flange or lip extending from the body around the periphery thereof. Typically, such seals are O-rings with an integrally molded lip which includes a plurality of spaced-apart slots formed therein to provide a fluid flow path through the lip until such time as a crimp is made which compresses the O-ring between two pipe fittings, completing the seal. The O-ring is dimensioned such that, prior to crimping, a fluid leakage path is provided by the slots formed in the flange or lip of the O-ring seal. In another embodiment of the invention, a coupling joint between two plumbing components is made using such a seal. 
         [0007]    These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a fragmentary cross-sectional view of a pipe and plumbing fitting employing an O-ring seal of the present invention, shown prior to crimping; 
           [0009]      FIG. 2  is an enlarged fragmentary perspective view of a female plumbing fitting including the O-ring seal shown in  FIG. 1 ; 
           [0010]      FIG. 3  is an enlarged perspective view of an O-ring seal embodying the present invention; 
           [0011]      FIG. 4  is a front elevational view of an O-ring embodying the present invention having a first diameter; 
           [0012]      FIG. 5  is a cross-sectional view of the O-ring shown in  FIG. 4 , taken along section lines V-V in  FIG. 4 ; 
           [0013]      FIG. 6  is an enlarged view of the circled areas VI shown in  FIG. 4 ; 
           [0014]      FIG. 7  is a front elevational view of an O-ring embodying the present invention having a larger diameter than that shown in  FIG. 4 ; 
           [0015]      FIG. 8  is an enlarged cross-sectional view of the O-ring taken along section lines VIII-VIII in  FIG. 7 ; 
           [0016]      FIG. 9  is an enlarged cross-sectional view of the O-ring taken along section IX-IX in  FIG. 7 ; 
           [0017]      FIG. 10  is an enlarged view of the circled area X in  FIG. 7 ; 
           [0018]      FIG. 11  is an enlarged cross-sectional view showing the initial step of inserting a pipe into a fitting including an O-ring of the type shown in  FIGS. 4-10 ; 
           [0019]      FIG. 12  is an enlarged fragmentary cross-sectional view of the pipe and fitting shown in  FIG. 11  as the pipe is advanced into contact with the O-ring of the present invention prior to crimping; and 
           [0020]      FIG. 13  is an enlarged cross-sectional view of the crimped connection between the pipe and female fitting into which it is inserted and sealed. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    Referring initially to  FIG. 1 , there is shown a first pipe fitting  10  having a female fitting which provides a coupling from a second pipe fitting, such as a supply conduit  12 . Conduit  12  is frequently referred to as a pipe, tube, or other vernacular in the trade. Fitting  10  can be any number of plumbing fittings, such as an adapter for different size piping, a threaded member for receiving a faucet or valve or other plumbing device, a coupling having an end mirroring the left end shown, or another conduit for extending the flow path of water. Typically, fittings  10  and  12  are made of copper. Fitting  10  includes an open end  16  and an internal annular concave groove  14  (frequently referred to in the trade as a bead) spaced inwardly from its open end  16  to hold an O-ring seal  20  of the present invention. End  13  of conduit  12  is inserted into the open end  16  of the fitting  10  until end  13  passes beyond O-ring  20 . Frequently, the fitting, such as fitting  10 , will have an annular shoulder  11  which engages the end  13  of conduit  12  and serves as a stop to the entry of the conduit well beyond the seal  20 . Subsequently, a commercially available crimping tool is employed and engages the outer circumferential surface  18  of groove  14  and crimps O-ring  20  into sealing engagement between the outer surface  15  of conduit  12  and the inner surface  17  of fitting  10 . 
         [0022]    In order to assure that such crimping has properly taken place, the O-ring  20  has a segmented flange  22  which, as seen in  FIGS. 2-10 , is integrally formed with O-ring seal  20  and extends radially from the body of seal  20 . The flange  22  is segmented into, for example, about eight segments for smaller seals, such as the ½ inch seal shown in  FIGS. 4-6 , or about  12  segments for larger seals, such as the 2 inch seal shown in  FIGS. 7-10 . The segmented flange  22  is formed by a plurality of slots  24  spaced equally around the periphery of the O-ring  20 . The segmented flange engages the outer surface  15  of conduit  12  loosely until a crimp is made. This allows fluid, such as water, to pass through the slots  24 , to provide a detectable leak at the junction between the conduit  10  and fitting  12  within a plumbing system in the event a joint has not been crimped. 
         [0023]    Typically, once, for example, the plumbing system of a floor for a commercial building is completed, the system for that floor will be isolated and pressure tested for leaks. Leaks are frequently pressure tested by applying air pressure initially at some location within the plumbing system which is otherwise sealed from the remainder of the overall system and monitoring the pressure, which may be at a level of 100 psi for air or 80 psi for water. These pressures may vary depending on a given location and plumbing practice. If the pressure is maintained over a period of time, the system is leak proof and the sealed crimping has been successful. If, however, the pressure drops, the faulty connection must be isolated. If a crimp has not been made or if a crimp is ineffective, the pressure will drop, indicating that there is a leak at a junction. If air is being used as a test media, the workman will spray a soap solution on the joints to detect air bubbles indicating where the leak occurs. If the junction has not been crimped, which will be evident from inspecting the outside of the junction, a crimp is made until the seal is completed. If an improper crimp exists, an attempt can be made to recrimp it, and, if that is unsuccessful, the fitting must be cut out and replaced with an adapter or junction fitting to replace the section removed due to the improper crimping. When water is employed as the media for testing the integrity of the system, the leakage of water will be readily apparent either where no crimp has taken place or where a defective crimp has been made. It is important to complete the leak detection and correct any leaks prior to completion of a plumbing installation and before enclosing the plumbing system with drywall or other materials. 
         [0024]    When properly crimped, O-ring  20  prevents leakage when the pressurized fluid flows through the connection in the direction indicated by arrow A in  FIG. 13 . Two different sizes of the O-ring seals  20  are shown in detail in  FIGS. 4-6  and  7 - 10 , respectively. In one embodiment for use with smaller pipes, such as a ½″ diameter copper pipe as shown in  FIGS. 4-6 , the groove  14  in fitting  10  had a radius of about 0.05 inches. The seal was made of a polymeric material, such as ethylene propylene diene elastomer with a generally circular body having a diameter of about 0.103 inches. Other polymeric or rubber based materials typically used for O-ring seals could also be used. The rectangular flange had a mean thickness of about 0.03 inches and extended radially outwardly from the circular body of seal  20  about 0.020 inches. The generally rectangular shaped slots  24  ( FIG. 6 ) had an annular width W of about 0.050 inches. For smaller seals  20 , i.e., less than about 1 inch, eight equally spaced slots provide the desired lead indicating function. In these embodiments, the arcuate flanges circumscribe an arc a ( FIG. 4 ) of about 35°. 
         [0025]    For larger sized seals (i.e., 1 inch or greater in diameter), a greater number of flanges  22  are employed. Thus, for example, as seen in  FIGS. 7-10 , for an O-ring having a diameter of 2 inches, twelve equally spaced flanges  22  are employed. Although seals  20  smaller than 2 inches also have a circular cross section, as shown in  FIGS. 4-6 , larger diameter seals, such as a 2 inch diameter seal shown in  FIGS. 7-10 , have an elliptical cross section, as described below, to accommodate the use of a conventional crimping tool. Thus, for example, as seen in  FIGS. 8 and 9 , the cross section of O-ring seal  20  has a major diameter D 1  of about 0.17 inches (±0.005 inches) and the minor diameter D 2  of about 0.151 inches (±0.004 inches). The flange  22  extends outwardly from the mid-section of the major diameter of the O-ring seal  20 , as seen in  FIG. 8 . Again, the flange  22  has a thickness of about 0.03 inches and extends outwardly from the elliptical body of O-ring seal  20  shown in  FIGS. 7-10  a distance of about 0.041 inches. O-ring seals  20  smaller than the 2 inch O-ring have a circular as opposed to an elliptical cross section and the 2 inch and larger diameter O-rings will employ an elliptical diameter with the minor axis being positioned within the groove  14  of a fitting, as described in connection with  FIGS. 11-13  below. 
         [0026]    In the embodiment shown in  FIGS. 7-10  and in other embodiments in which twelve equally spaced flanges are employed, the width W of the slots  24 , as seen in  FIG. 10 , is about 0.1 inches. Each of the arcuate flanges  22  circumscribe an angle β of about 24°. In each of the embodiments, the material is ethylene propylene diene elastomer, as noted above, having a hardness of 70 shore and conforms to ASTM D2000 Class M3DA714. Having described the typical different sized O-ring seals  20  of the present invention, the installation and crimping of the seal is illustrated by the sequential diagrams of  FIGS. 11-13  now described. 
         [0027]    As seen in  FIG. 11 , a fitting  10 , which can be any type of copper coupling or fitting used in a plumbing connection, includes an internal annular groove  14  into which an O-ring seal  20  of the present invention is inserted with the inwardly projecting flanges  22  aligned axially (i.e., orthogonally) with the longitudinal axis L of fitting  10 . Conduit  12  is inserted into the open end of fitting  10  in a direction indicated by arrow B in  FIG. 11 . As the forward edge  13  of conduit  12  engages flange  22 , as seen in  FIG. 12 , the O-ring seal  20  rotates on its annular axis, as shown by arrow C in  FIG. 12 , approximately 30°. This movement moves any area of O-rings  20  which may have been damaged by a rough edge  13  of a conduit  12  into a non-sealing area of the O-ring, which does not make contact with the outer surface  15  of conduit  12  or the inner surface of groove  14 . The conduit  12  is advanced beyond the O-ring  20  to a position, as illustrated in  FIG. 1 , in which the end  13  typically engages a stop  11  in the fitting  10 . After this, a conventional crimping tool is applied to the area D ( FIG. 13 ) around the entire 360° periphery of the bead or groove  14  to compress the O-ring seal  20  and flanges  22 , as seen in  FIG. 13 , to complete the sealed connection between the outer diameter  15  of the pipe or conduit  12  and the inner surface  17  of fitting  10 . 
         [0028]    As seen in  FIG. 13 , this deforms the either circular or elliptical cross section of the O-ring seal  20  compressing it against the inner surface of groove or recess  14  and the outer surface  15  of the conduit  12 . As noted above, the two fittings which are being coupled together in sealed relationship may take any form of a typical copper plumbing fitting, including pipes, double ended connectors having a bead or groove on opposite ends for receiving conduits  12  from opposite ends for coupling ends of conduits, threaded fittings for coupling a smooth conduit to a threaded fitting, such as a valve, or any different diameter adapters. Thus, the leak evident seal  20  of the present invention can be employed in a variety of plumbing environments where two fittings are to be coupled utilizing a push and crimp fitting and an O-ring to a provide leak evident system for a plumbing installation. 
         [0029]    The flange  22  on the O-ring  20  also assists in providing the installer a tactile consistent feel as the pipe is inserted into the fitting. This and the rotating of the ring seal helps prevent actually contacting and damaging the rubber O-ring sealing surface, which is one of the greatest causes of leaking press fittings. Additionally, flange  22  helps to retain the fitting on the pipe during the dry fitting of a plumbing system before crimping occurs. This is a great aid to the installer since the fittings won&#39;t fall off of the pipe prior to insertion. 
         [0030]    It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.