Abstract:
A pipe coupling for connecting a pipe to a flange associated with another pipe in a sealed manner. The pipe ( 10 ) is formed with circumferential groove ( 10   a ). The coupling comprises a gasket ( 20 ), a mounting ring ( 18 ), and a mounting flange ( 22 ). The ring ( 18 ) is elastically expandable, e.g. by being split, and formed with projecting rib ( 18   a ) adapted to fit into the groove ( 10   a ) and hold the ring affixed to the pipe ( 10 ). The mounting flange ( 22 ) is tightened against both the ring ( 18 ) and a counter-flange ( 12 ), through matching cone-shaped surfaces ( 18   c,    22   a ).

Description:
The present patent application is a non-provisional application of International Application No. PCT/IL02/00427, filed May 30, 2002. 
     FIELD OF THE INVENTION 
     The present invention relates to pipe couplings of the type adapted to sealingly connect a pipe to a flange of a vessel or the like, or to connect two ends of pipes extending co-axially one with respect to the other. 
     BACKGROUND OF THE INVENTION 
     The most popular pipe coupling presently used for the above purposes is of the type known as hingeable split collar. It comprises a matched pair of half-circular collars hinged to each other at one end and provided with lugs at the other end. The collars are formed with rims or shoulders adapted to fit into and hold against complementary circumferential grooves formed near the ends of the pipes. An elastomeric circular gasket is used, surrounding the space between and partly extending over the pipe ends. Once the collars are tightened to each other, by a bolt passing through the respective lugs overlying each other, the gasket becomes compressed to provide a seal between the pipes. 
     Pressure admitted into the pipes is effective to enhance the sealing effect by further pressurizing of the gasket against the rims of the collars. 
     These split collar couplings are inherently inconvenient for use, demanding certain manipulation and application of physical force during the initial mounting stage. 
     Other deficiencies of the conventional couplings are that they need to be made of metal, and hence they are heavy and wasteful in terms of storage and transportation space. 
     It is the prime object of the present invention to provide a pipe coupling of simple, plastic molded integral construction, and allowing a wide range of variations satisfying different pipe-work conditions. 
     It is a further object of the invention to make use of the standard grooved pipe ends as applied in conjunction with the split collar couplings. 
     SUMMARY OF THE INVENTION 
     Provided according to the invention is a pipe coupling for connecting a pipe to a flange associated with another pipe in a sealed manner, wherein the pipe is formed with a circumferential groove the coupling comprising a gasket, a mounting ring, and a mounting flange, characterized in that the ring is elastically expandable, and formed with projection means adapted to fit into the groove and hold the ring affixed to the pipe while the mounting flange is tightened against both the ring and a counter-flange. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and additional constructional features and advantages of the invention will be more clearly understood in the light of the ensuing description of several preferred embodiments thereof, given by way of example only with reference to the accompanying drawings, wherein— 
         FIG. 1  is a cross-sectional view of a pipe coupling featuring the characteristics of the present invention as used for connecting a pipe to an outlet/inlet flange of a fluid vessel; 
         FIG. 2  shows a detail of the coupling of  FIG. 1  on an enlarged scale; 
         FIG. 3  is a sectional view taken along line III-III of  FIG. 1 ; 
         FIG. 4  is a sectional view taken along line IV-IV of  FIG. 1 ; 
         FIG. 5  is a perspective exploded view of the pipe coupling of  FIG. 1 ; 
         FIG. 6  is a cross-sectional view of a pipe coupling according to another embodiment of the invention used for connecting together a pair of pipes; 
         FIG. 7  shows a detail of the coupling of  FIG. 6  on an enlarged scale; 
         FIG. 8  illustrates a modified elastomeric gasket; 
         FIG. 9  illustrates a modified mounting split ring; 
         FIG. 10  illustrates a further modification of the mounting split ring; 
         FIG. 11  is a modification of the ring of  FIG. 10 ; 
         FIG. 12  is a perspective view of a mounting ring of a hybrid, multi-segment structure; 
         FIG. 13  is a top view of ring of  FIG. 12 ; 
         FIG. 14  is a sectional view taken along line XIV-XIV of  FIG. 13 ; and 
         FIG. 15  shows a mounting split ring worked out of sheet metal. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-5 , there is shown a pipe  10  coupled to a flange  12  by a series of bolts  14 . The flange  12  may be welded or otherwise form part of, for example, a fluid vessel (not shown) via a pipe section  16 . 
     The coupling comprises three parts: a split mounting ring  18 ; an elastomeric gasket ring  20 ; and a mounting flange  22 . 
     As more clearly seen in  FIGS. 2 and 5 , the pipe  10  is formed with a circumferential groove  10   a  similar to that used in connection with the conventional hingeable collar couplings. 
     The split mounting ring  18  is typically made of plastics, and formed with a circular rib  18   a  configured to fit into the groove  10   a.    
     The rib  18   a  is preferably of a generally saw-tooth shape (see  FIG. 2 ), whereby the leading side  18   a ′ thereof exactly matches the right angled side wall of the groove  10   a  while at the opposite side  18   a ″ it is beveled as shown, for a reason to be explained further below. 
     The ring  18  is further formed with a circular recess  18   b  for snugly receiving gasket  20 . 
     The outer contour of the ring  18  has a cone-shape surface  18   c , preferably between 15° and 30°, merging with an upright shoulder  18   d.    
     Finally, the ring  18  is split by a cut  18   e , for enabling the spreading or expansion thereof to an extent allowing it to be forced over the open side of the pipe  10  and pushed further until the rib  18   a  clicks into the groove  10   a.    
     The gasket  20 , usually of rubber or other suitable elastomeric material, is preferably formed with an inner slot  20   a  for its expansion under the pressure of the flowing through liquid as known in the art (“hydraulic seal”). 
     The mounting flange  22  has an inner cone-shaped surface  22   a  of the same inclination and length as of the surface  18   c  of the ring  18 , so that when the bolts  14  are tightened, a firm grip around the ring  18  is achieved along with an axially directed force component acting against the shoulder  18   d , as requested for sealing the gasket  20  against the face of the flange  12  in the assembled position of the coupling. 
     The flange  22 , with bores  22   b  for the bolts  14 , is preferably formed with arcuate projections  22   c  compensating the width of the shoulder  18   c.    
     The manner of assembling the coupling is self-evident in view of the foregoing description. As seen in  FIG. 5 , the flange  22  is first placed over the pipe  10 . Then the mounting split ring  18  is forcibly dressed over the end of the pipe, which is facilitated by the elastic expansion assisted by the beveled portion  18   a ″ of the rib  18   a.    
     Once properly seated over the pipe  10 , namely that the rib  18   a  grips around the groove ( 10   a ), the gasket  20  is placed into the recess  18   b , and the flange  22  is dragged over the ring  18  in the direction of the flange  12  to which it is intended to be fastened. 
     The counter-force requested to withstand the tightening of the flanges  12  and  22  to each other using the bolts  14 , thereby squeezing of the gasket  20  to a proper amount, is offered by the rib  18   a  trapped within the groove  10   a , or, more accurately, the abutment of the portion  18   a ′ against the upright wall of the groove  10   a.    
     The coupling substantially as so far described is readily useful for connecting two pipes of equal (or even unequal) diameters, as depicted in  FIGS. 6 and 7 , where similar reference numerals are used to denote already identified parts and components. As illustrated pipe  110  includes circumferential grooves  110   a  and  210   a . Bolts  114  and  214  form a grip around the ring  118  when tightened. 
     As clearly seen, two couplings are employed, in a “face-to-face” engaging relationship. Hence, the left-hand side pipe  110  is assembled with mounting split ring  118 , gasket  120  and mounting flange  122 , which is tightened to flange  222 , surrounding split ring  218  and gasket  220  (rather than to the fixed flange  12  as in the previous embodiment). Thus, the pipe  110  becomes sealingly connected to the pipe  210 . 
     Several modified embodiments will be now described, demonstrating the versatility and other advantages of the present invention. 
     Referring to  FIG. 8 , there is exemplified a gasket  320  provided with a thin flap or tongue  320   b  designed to be inserted into slot  318   e  of the split ring  318 . The positioning of the flap between the ring sections will add some flexibility that will compensate for any deviation of measurement or surface irregularities between the ring and the surrounding mounting flange (not shown), allowing less stringent tolerance control during production. 
     The mounting split ring  418  of  FIG. 9  is formed with a cut-through slot  418   e  extending at an angle with respect to axial direction. 
     Rather than employing a split ring, it is possible to have it composed of more than one segment (two segments in ring  518  in  FIG. 10  and three in ring  618  in  FIG. 11 ), held together by a rubber band ( 524  and  624 , respectively). 
     The mounting ring  718  of  FIGS. 12-14  is again of a modified design. A series of metal inserts  726  are positioned between the segments. An elastic band  728  is threaded through all segments and inserts enabling the expansion of the ring  718  as requested for the mounting thereof over a pipe (not shown). The inserts conform the shape of the mounting ring as dictated for its use, namely with teeth  718   a  (replacing the continuous rib  18   a  of  FIG. 1 ) and the cone-shaped outer surface  718   c.    
     The hybrid or composite structure of the ring  718  offers enhanced firm grip of the ring against the grooved pipe (not shown), as well as electrical short-cut between coupled pipes in case such is demanded. 
     The mounting ring  818  of  FIG. 15  is produced not by plastic molding, but of sheet metal processed by known technologies (rolling) to the final shape. It will be noted that the continuous cone-shaped surface (denoted  18   c  in  FIG. 2 ) is divided into two: portion  818   c ′ and portion  818   c ″ which together suitably support the inner cone-shaped surface of the mounting flange (not shown). 
     Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations and modifications can be effectuated without departing from the true spirit and scope of the invention as defined in and by the appended claims.