Abstract:
A pipe coupling for connecting pipes of the same or different diameters. The coupling has a barrel sleeve with clamping rings on each end. The clamping rings each carry nested seals. An inner portion of each nested seal may be removed so as to adapt the clamping ring to different pipe diameters. Each clamping ring is hinged, but becomes iron-bound upon tightening, so that each ring eventually bends as a unitary ring member.

Description:
TECHNICAL FIELD 
     The invention disclosed here relates to a pipe coupling. The pipe coupling is adapted to join two large pipes together via a barrel sleeve that has clamping rings on each end. The clamping rings have seals adapted to join pipes having the same diameter or different diameters. 
     BACKGROUND OF THE INVENTION 
     There are many different types of pipe couplings and connectors for joining water, sewage, gas, and similar pipes. An example of one such coupling is disclosed in U.S. Pat. No. 5,941,576. The design disclosed here provides an alternative to the &#39;576 design. 
     SUMMARY OF THE INVENTION 
     The invention disclosed here is an improved pipe coupling. The pipe coupling includes a cylindrical, barrel-shaped sleeve portion that has circumferential flanges at each end. The circumferential flanges face outwardly relative to the sleeve. Connected to each circumferential flange is a clamping ring. 
     In preferred form, the clamping rings are identical in construction. Each clamping ring carries a nested seal. Each clamping ring may consist of two separate portions, or halves, that are hinged together at the bottom, although variations are possible. 
     The hinge creates a pivot point so that each half of the clamping ring (or clamping ring portion) is movable toward and away from the other one. However, the clamping ring portions are structurally configured so that they eventually become iron-bound near the pivot point at a certain rotational point, as the clamping ring portions move toward each other during closing or tightening. The iron-bounding effect causes the clamping ring portions to eventually function as a “unitary” ring instead of two separate freely-moving halves. 
     As an alternative, it may be possible to use the same concept in a clamping ring having several segments. In this instance, one segment or portion swings relative to another via a pivoting or similar connection. The two portions become iron-bound at a certain inward swing point. 
     As indicated above, for the two-part arrangement, each half of the clamping ring has an ear adapted to connect to a tightening bolt. The ears of each clamping ring portion are pulled together by the tightening bolt in a conventional manner. However, the ears are integrated with the structure of the clamping ring portions, as opposed to being separately welded or the like. 
     Each clamping ring carries a nested seal. According to the invention disclosed here, the nested seal includes an inner circumferential seal part that is separately nested within an outer circumferential seal part. The combination of these two seal parts creates an inwardly directed face that presses against an outwardly directed face of the corresponding barrel sleeve&#39;s circumferential flange. 
     The nested seal also has a sloping outer surface received within the clamping ring. The slope on the surface causes the seal to be urged toward the barrel sleeve&#39;s circumferential flange as the clamping ring is tightened. 
     The inner part of the nested seal has a plurality of outer peripheral ridges that mate with a corresponding plurality of inner peripheral grooves on the inside of the outer part of the seal. This permits the inner part to be removed easily from the outer part and allows the clamping rings to be adjusted to pipes of varying diameters. 
     The outer part of the seal also has an annular groove that faces the barrel sleeve&#39;s flange. The diameter of the annular groove is greater than the inner diameter of the barrel sleeve&#39;s flange, when in a non-compressed state. However, when the clamping ring is tightened about the circumferential flange on the sleeve, the seal is compressed down such that the annular groove becomes exposed to the interior diameter of the pipe. 
     Last, the cylindrical, barrel-shaped sleeve portion carries a handle. The sleeve is preferably designed to couple together the ends of two pipes having interior diameters within and including four to twelve inches. The handle allows for the pipe coupling to be physically manipulated (e.g., turned or held in position) much easier when it is used to couple pipes. 
     The features summarized above, including how they interact with each other, are further described below and in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference numerals and letters refer to like parts throughout the various views, unless indicated otherwise, and wherein: 
         FIG. 1  is a perspective view of a pipe coupling constructed in accordance with a preferred embodiment of the present invention; 
         FIG. 2  is a side view of the pipe coupling shown in  FIG. 1 ; 
         FIG. 3  is an end view of the pipe coupling shown in  FIGS. 1 and 2 ; 
         FIG. 4  is a perspective view of one of two clamping rings illustrated in  FIGS. 1-3 , with the clamping ring and related seal structure removed from the barrel sleeve portion of the pipe coupling; 
         FIG. 5  is a view like  FIG. 4 , but reveals underlying nested seal and backing armor structure; 
         FIG. 6  is a view like  FIG. 4 , but with the nested seal removed; 
         FIG. 7  is a pictorial view of the nested seal, and shows a backing armor plate on an outer surface of the seal; 
         FIG. 8  is a view like  FIG. 7 , taken at a different angle, and shows the backing armor plate removed; 
         FIG. 9  is a pictorial view like  FIG. 8 , but taken at a different angle, and shows only the outer circumferential portion of the nested seal, with the inner circumferential portion having been removed; 
         FIG. 10  is a pictorial view of the outer circumferential portion of the seal; 
         FIG. 11  is a pictorial view like  FIG. 4 , but shows the inner circumferential portion of the seal removed from the outer one; 
         FIG. 12  is a side view of  FIG. 11 , but with the seal removed for the purpose of illustrating how the clamping ring is shaped to receive the nested seal; 
         FIG. 13  is a side view of  FIG. 11  and shows the nested seal in position within the clamping ring; 
         FIG. 14  is a bottom view of one clamping ring portion and shows the hinge part of a releasable pin and hinge connection that permits two separate clamp ring portions to rotate relative to each other; 
         FIG. 15  is a view like  FIG. 14 , but shows the pin portion; 
         FIG. 16  is a pictorial view of the cylindrical barrel sleeve portion of the pipe coupling; 
         FIG. 17  is a frontal view of an alternative embodiment of a clamping ring that functions like the clamping ring illustrated in  FIG. 4 ; and 
         FIG. 18  is a view like  FIG. 17 , but is taken looking at the opposite side of the clamping ring. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, and first to  FIG. 1 , shown generally at  10  is a pipe coupling constructed in accordance with a preferred embodiment of the invention. The coupling  10  consists of a cylindrical, barrel-shaped sleeve  12 . 
     Referring briefly to  FIG. 16 , the barrel-shaped sleeve  12  has a carrying handle  14 . Each end of the barrel-shaped sleeve  12  terminates in a circumferential flange  16 ,  18 . Each flange  16 ,  18  presents an outwardly facing surface  20  (see  FIG. 16 ). As can be seen in  FIG. 2 , the barrel sleeve  12  converges at  22 ,  24 , respectively, toward each circumferential flange  16 ,  18  (not shown in  FIG. 2 ). 
     In preferred form, and referring back to  FIG. 1 , a clamping ring (indicated generally at  26 ,  28 ) is connected to each circumferential flange  16 ,  18  on the sleeve  12 .  FIG. 3  is an endwise view of the pipe coupling  10  and shows only clamping ring  26 . In the alternative view provided by  FIG. 4 , the clamping ring  26  is shown alone and disconnected from the pipe coupling  10 . 
     In the embodiment described here, each clamping ring  26 ,  28  is identical. It is to be appreciated, however, that variations would involve making one clamping ring larger or smaller relative to the other. It might also be possible to use the clamping ring and seal design disclosed here in other kinds of pipe coupling applications. Nevertheless, because clamping rings  26 ,  28  are identical in the drawings, only one clamping ring  26  will be described. 
     The clamping ring  26  is made of two separate portions, or halves  30 ,  32 . These portions are connected together at a pivot point  34  (see, e.g.  FIG. 3 ). The pivot point  34  allows each part  30 ,  32  of the clamping ring  26  to open and/or close at the top as a bolt structure  36  (described later below) is respectively loosened or tightened. 
     The pivotal connection  34  is created by the structure illustrated in  FIGS. 14 and 15 . These figures are views that depict the bottom side of clamping ring  26 . One portion or half  30  of the clamping ring  26  has a hinge piece  38 . The hinge piece  38  has forked hooks  40 ,  42  that capture a pin  44  on the bottom of the other clamping ring part  32 . The hooks  40 ,  42  are easy to connect and disconnect to and from the pin  44  for completely separating the two halves, if desired. 
     Referring now to  FIGS. 5 and 6 , but first to  FIG. 6 , the clamping ring  26  is compressed around the barrel sleeve&#39;s circular flange  16  by the bolt structure  36 . The bolt structure design is conventional. It includes a bolt head  46  that is captured by a bolt guide  48 . The bolt guide  48  is curved and rests against a complementary curved surface  50  that is part of a clamping ring ear  52  (see  FIG. 3 ). The ear  52  is made from the same piece of material (metal) that makes up the clamping ring portion  26 . In other words, the ear  52  is structurally integrated or integrated with the structure of the clamping ring portion. 
     The other end of the bolt structure  36  has a nut  54  threaded onto the shaft  56  of bolt structure  36 . The nut  54  similarly rests against a mirror bolt guide  58 . Similar to the previous description, bolt guide  58  rests against a curved surface  60  on clamp ear  61 . 
     Referring once again to  FIG. 4 , the clamping ring  26  carries a nested seal, indicated generally at  62 . The seal  62  is called “nested” because it has an outer circumferential seal part  64  (see  FIG. 9 ) and an inner circumferential seal part  66  (see  FIG. 10 ). 
     The inner seal  66  has a plurality of outer peripheral ridges  68 ,  70 . These ridges mate with or fit within corresponding inner peripheral grooves  72 ,  74  on an inner surface  76  of the outer seal  64  part (see  FIGS. 9 and 10 ). The arrangement of peripheral ridges  68 ,  70  and grooves  72 ,  74  help retain the inner seal  66  in position within the outer seal  64  thus creating the desired “nested” configuration. 
     The nested combination created by the inner and outer seal parts  66 ,  64  can be used to define an adjustable seal for capturing the end of pipes having variations in outer diameter. If desired, the inner seal  66  can be easily removed from the outer one  64 , in the field, thereby adapting the clamp ring  26  to a larger pipe. The two seals  66 ,  64  are not joined together via an adhesive or other bonding agent. They exist as separate pieces. It is possible to reinstall the inner circumferential seal part  66 , if desired. 
     Referring now to  FIG. 12 , which shows the clamping ring part  30  without the nested seal  62 , it can be seen that the clamping ring is generally conventional in cross section, except as described below. The clamping ring has an inner lip  77  that overlaps the barrel sleeve&#39;s circumferential flange  16  (not shown in  FIG. 12 ). In other words, the circumferential flange rests within the space indicated by arrow  78  in  FIG. 12 . As would be apparent, removing the nut  54  from the end of the bolt structure  36  allows the clamping ring  26  to be opened sufficiently so that the clamping ring can be placed around the circumferential flange  16 . 
     Outwardly of space  78  is a unique sloped surface  80  in which the nested seal  62  rests. The slope of surface  80  is convergent outwardly (toward the end of the pipe coupling  10 ). As the bolt structure  36  is tightened, it pulls clamp ears  52 ,  61  toward each other, thus compressing the nested seal  62 . At the same time, the compression action also urges the sloped surface  80  of the clamping ring against the corresponding surface (also sloped)  82  of the nested seal (see  FIG. 9 ). This, in turn, urges the seal  62  toward the circumferential flange  16 . 
     Referring now to  FIG. 4 , the inwardly facing surface of the seal, indicated generally by arrow  84 , is further urged or pressed against the outwardly facing surface  20  of the sleeve&#39;s circumferential flange (see  FIG. 16 ). This collectively enhances sealing capability because not only is the nested seal  62  compressed around the outside diameter of the pipe, but it is also compressed axially into and against the barrel-sleeve&#39;s circumferential flange. 
     Next, the outer part  64  of seal  62  has an annular groove  86  that faces the barrel sleeve  12 . When the clamping ring  26  is placed on its respective flange, and before tightening of the bolt structure  36 , the seal  62  is in a non-compressed state. In this condition, the diameter of the annular groove  86  is preferably greater than the inner diameter of the barrel sleeve  12 . When compressed, however, the annular groove  86  becomes likewise compressed so that its diameter becomes exposed to the inside of the barrel sleeve  12 . This enables fluid pressure to cause one part of the seal to slide upon itself. It is believed this may improve upon seal efficiency. 
     Referring to  FIG. 7 , there is a backing armor piece  88  that fits over a region  90  (shown in  FIG. 11 ) in outer seal part  64 . The armor piece  88  rests underneath clamping ring ears  52 ,  62  and spans the distance or gap between the ears.  FIG. 8  shows where the armor piece  88  normally rests on the seal. As the bolt structure  36  is tightened, the armor piece serves to compress the seal  62  and prevents the seal from bulging in the region where the bolt structure  36  is located. 
     Directing attention now to the bottom of  FIG. 4 , as was described above, the clamping ring  26  consists of two separate parts  30 ,  32 . These parts  30 ,  32  may swing or move toward and away from each other because they are connected at pivot point  34 . 
     As is apparent from the above description, the ears  52 ,  62  may open relative to each other. When this happens, it creates a space or gap at the location indicated generally by arrow  92  in  FIGS. 3 and 4 . In that circumstance, the parts  30 ,  32  of the clamping ring  26  are “pivoting.” As the clamping ring  26  is tightened, however, the edges  94 ,  96  of each respective clamping ring part  30 ,  32  come into abutting contact with each other at reinforced region  33  (see  FIG. 6 ) and constrain or stop further free-pivoting movement. At that particular point, because clamping rings  30 ,  32  cease moving freely, further clamp tightening is accomplished by bending within the integrated structure of parts  30 ,  32 . In other words, the clamping ring  26  then begins to function as though it is a “unitary” ring made of a single piece. 
     Finally, an alternative embodiment of clamping ring  26  is illustrated in  FIGS. 17 and 18 . Directing attention there, the alternative embodiment consists of a ring that is segmented into three parts  98 ,  100 ,  102 . Each part is connected together at  104 ,  106  by the same type of hook and pin connection described earlier. These connections create pivot points that enable ring segments  98 ,  100 ,  102  to swing freely relative to each other when the clamping ring  26  is unbolted. However, as one separate portion swings relative to the other in a closing motion, the two portions eventually become iron-bound in the same manner as described above. This occurs at the locations indicated at  108  and  110 , respectively. The iron-binding or bounding effect enables a three-segment ring to function as a single unitary ring at a certain tightening point. The advantage to this design is that the compressive forces created by the ring are distributed more evenly. Likewise, the nested seal  62  receives evened-out compression around its circumference. 
     The foregoing is not intended to limit the scope of patent coverage. The scope of patent coverage is intended to be limited by the patent claims, the interpretation of which is to be made in accordance with the established doctrines of patent claim interpretation.