Abstract:
A coupling assembly for joining pipe ends includes a main body sleeve with a shoulder incorporating a sloped step. The main body sleeve has an inner surface with two claiming rings. The assembly further includes a swage ring which is moveable along the outer surface of the pipes. The inner surface of the swage ring includes ramps. The ramps force clamping rings to engage the pipe and form a seal as the swage ring is urged inward towards the main body sleeve. Additionally, the clamping ring includes a tab incorporating a sloped surface with a contour complementary to that of the sloped step. The surface of the clamping ring engages and presses against the surface of the sloped step, thus preventing movement of the swage ring away from the main body sleeve. The disclosure also pertains to a method of joining two pipes utilizing the disclosed coupling assembly.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part bypass of and claims priority under 35 U.S.C. 111(a) to International Application PCT/CN20121079161, with an international filing date of Jul. 26, 2012, which is incorporated herein by reference. International Application PCT/CN20121079161 claims priority to Chinese Application No. 201220151938.X, with a filing date of Apr. 12, 2012, which is incorporated herein by reference. 
       RELATED ART 
       [0002]    Pipe fitting involves the installation or repair of piping or tubing systems that convey liquid, gas and semi-solid materials. This work typically includes selecting and preparing pipe or tubing, joining it together by various means, and finding and repairing leaks. Pipe fitting work is done in many different settings, for example HVAC, manufacturing, and hydraulics. Joining pipes often involves the use of welding, soldering or bonding. Each of these methods presents various safety and environmental concerns, such as the risk of fire or explosion, exposure to dangerous chemicals, and ozone formation. In addition, these methods require extensive post-fitting treatments which are very labor intensive and costly. The welding, soldering and bonding methods add additional materials to the joined pipe, possibly dramatically increasing the weight of the final project. 
         [0003]    Conduit couplings are often used in welding and other crafts to join the ends of pipes. Conduit couplings often utilize compression fittings, which are used in plumbing and electrical conduit systems to join two tubes or thin-walled pipes together. Swage fittings or rings are used to couple pipes carrying a variety of liquids or gasses. These couplings generally cause the deformation of a portion of the pipe and the fitting in response to the application of a compressive force. Swage fittings often utilize sealing projections or teeth to engage the pipe during installation. Generally, force is applied to the sealing teeth sequentially to reduce the installation force that would be required to seal the teeth simultaneously. The sequential application of compression force may cause a loss of bad force on one of the teeth, resulting in “kickback” or the development of a gap between the tooth and the underlying pipe. In addition, the sealing ability of traditional couplings may be compromised because of vibrations or other types of movements or forces, particularly under high pressure applications. These fittings would then require post-installation procedures which are both expensive and time consuming. 
         [0004]    What is needed in the art, therefore, are coupling devices that provide improved sealing capability to prevent loss of the seal and costly, time consuming post-installation procedures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the several views. 
           [0006]      FIG. 1  is a cross sectional view of the conduit coupling of the disclosure in a disengaged position. 
           [0007]      FIG. 2  is a cross sectional view of the conduit coupling of the disclosure in an engaged position. 
           [0008]      FIG. 3  is a cross sectional view of a swage ring engaged with a shoulder of a sleeve of a conduit coupling, as depicted by  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]      FIGS. 1   2 , and  3  depict a cross section of a conduit coupling  10  utilized to join the respective ends of two pipes  12  and  14 , As will be appreciated by one of skill in the art, the coupling has a ring-like shape and surrounds the exterior surface of pipes  12  and  14 . Pipes  12  and  14  are constructed from any raw material suitable for piping as is known to one of skill in the art. For example, pipes  12  and  14  may be constructed from steel, steel alloys such as unfinished, black (lacquer) steel, carbon steel, stainless steel or galvanized steel, iron, brass, ductile iron, aluminum or copper. In one embodiment, pipes  12  and  14  are constructed from the same material. In an additional embodiment, the pipes  12  and  14  are constructed from differing materials such as metal and plastic. in one non-limiting example, the conduit coupling  10  may join pipes with a diameter between ¼ inch and 6 inches (4 mm to 168 mm). In an additional embodiment, the coupling  10  joins pipes of the same diameter. However, the disclosure is not limited in such a way as the conduit  10  may also join pipes with different diameters. 
         [0010]    In the embodiment illustrated in  FIGS. 1 and 2 , conduit coupling  10  includes a main body cylindrical sleeve  20  which is adapted to receive the respective ends of pipes  12  and  14 . Sleeve  20  fits over a terminal end of each pipe  12  and  14  in order to engage sealing elements and provide tight seals around pipes  12  and  14 . The seal will prevent the leakage of both gasses and liquids at the junction of the two pipes. Cylindrical sleeve  20  includes a contoured outer surface. A stop  22  is located at the center of the sleeve  20  and projects partially into the interior of the pipes  12  and  14 . The respective ends of pipes  12  and  14  abut against the protruding portion of stop  22  when they enter the sleeve  20 , thus helping to stabilize the pipes during installation. 
         [0011]    The conduit coupling  10  further includes two movable cylindrical swage rings  30  and  32 . As will be described in greater detail below, a tool (not shown) applies inward compressing pressure along the entire circumference of swage rings  30  and  32 . This inward compression pressure urges the swage rings  30  and  32  towards the center of the conduit, i.e., towards the main body sleeve  20  and stop  22 . Swage rings  30  and  32  act to lock and seal the conduit coupling  10  onto the outer surface of tubes  12  and  14 . As shown in  FIG. 1 , swage rings  30  and  32  are illustrated in the disengaged position, i.e., they have not been urged towards and do not yet contact main body sleeve  20 . As will be discussed in greater detail below,  FIG. 2  illustrates swage rings  30  and  32  in the engaged position as they are in contact with main body sleeve  20 . Any description of one of swage rings  30  or  32  is applicable to the remaining swage ring. 
         [0012]    Turning again to  FIG. 1  illustrating disengaged swage rings  30  and  32 , the bottom surface of each swage ring  30  and  32  has an inclined inner ramp  70  located immediately adjacent to and on the outward side of protrusion  40  (located on the upper surface of main body sleeve  20 ). The inclined nature of inner ramp  70  produces a space or area  100  where there is no contact between the swage ring  30  and the inner sleeve  20  as the sleeve  20  is urged to the engaged position. Moving outward towards the terminal ends of pipe  12 , the swage ring  32  further includes an inner and  74  which is substantially parallel to line  45  and is located immediately adjacent to inner ramp  70 . Also present on the bottom surface of swage ring  30  is an inclined outer ramp  72 . Outer ramp  72  is immediately followed by outer and  76  which is substantially parallel to axis  45 . Similar to the inner ramp  70 , the inclined nature of outer ramp  72  produces a space or area  102  where there is no contact between the swage ring  30  and the inner sleeve  20  as the sleeve  20  is urged to the engaged position. Swage ring  32  includes similar corresponding structures. 
         [0013]    The lower surface of the main body sleeve  20  includes an inner clamping ring  42  located directly opposite protrusion  40  and an outer clamping ring  44  located at the outer edge of sleeve  20 . As will be described in more detail below, the inner clamping ring  42  and outer clamping ring  44  are shaped as protrusions which project down and contact the pipe  12 . The inner clamping ring  42  and outer clamping ring  44  act as “teeth” and engage the outer surface of pipe  14 , forming a seal between the pipe  14  and the conduit  10  when the sleeve  20  is urged to the engaged position. The portion of the main body sleeve  20  as illustrated in the engaged position ( FIG. 2 ) has similar structure as described above. 
         [0014]    Referring again to  FIG. 1 , swage ring  30  further includes a retaining ring  60  with a sloped surface  66 . Additionally, the upper surface of main body sleeve  20  includes shaft shoulders  50  and  52  that are separated by an annular groove  53 . Shaft shoulder  50  further includes a step  62 , which extends around the entire circumference of and at the edge of shaft shoulder  50 . As illustrated in  FIG. 1 , the surface  64  of step  62  is sloped. As will be described in more detail below, the sloped surface  66  of retaining ring  60  is complementary to the sloped surface  64  of step  62 . As the swage ring  12  is urged towards the sleeve  20 , the two surfaces  66  and  64  make contact and are forced together into a locked orientation ( FIGS. 2 and 3 ) that creates a tight fit and resists movement of the swage ring in a sidewise direction along line  45 . In one embodiment, the surface  66  of retaining ring  60  is convex shaped (a surface that curves outward or downward), while the surface  64  of step  62  is concave. These two surfaces  64  and  64  have complementary corresponding structure so that they fit together snugly and are retained in a locked position during the application of force. In the presence of forces that tend to pull the swage ring  12  away from the shoulder  50 , the surface  66  of the retaining ring  60  presses against the surface  64  of the step  62  in response to such forces thereby resisting movement of the swage ring  12  away from the shoulder  50 . The portion of the main body sleeve  20  as illustrated in the engaged position ( FIGS. 2 and 3 ) has similar structure as described above. 
         [0015]    In practice, the two opposing ends of pipes  12  and  14  are placed adjacent to the interior surface of the sleeve  20 . The ends of pipes  12  and  14  are inserted into opposite ends of the sleeve  20  so that the conduit  10  is fitted externally around the circumference of pipes  12  and  14 . The inner clamping ring  42  and outer clamping ring  44  contact the exterior surfaces of pipes  12  and  14 . As described previously, the pipes  12  and  14  may be constructed from any material suitable for conveying a fluid, gas or semi-solid, as is known to one of skill in the art. The diameters of conduit  10  and sleeve  20  are sized such that they fit snugly over the ends of pipes  12  and  14 . During insertion, the respective ends of pipes  12  and  14  move towards the midpoint of sleeve  20  until each abuts against opposing sides of protruding portion of stop  22 . In the disengaged position illustrated in  FIG. 1 , the inner ramp  70  and the inner land  74  are located immediately adjacent to and on the outward side of the protrusion  40 . Outer ramp  72  and outer land  76  are located on the portion of the swage ring  32  located after the termination of the sleeve  20 . The pipes  12  and  14  may be of any diameter desired for its intended use, and the diameter of the ends of sleeve  20  may be of any diameter desired to accommodate pipes  12  and  14 . No lubrication or pretreatment of the pipes  12  and  14  is necessary. The conduit  10  is fitted externally around the respective ends of pipes  10  and  12 , resulting in no change to the internal diameter of the pipes  12  and  14 . 
         [0016]    A swage press tool (not shown) utilized for installation of the conduit  10 , as is known to one of skilled in the art, is placed over sleeve  20 . Axial force is applied to sleeve  20  via the press tool (not shown). This compressing force urges swage rings  30  and  32  inward towards the center of sleeve  20  to their final engaged positions as shown by  FIGS. 2 and 3 . Turning again to  FIG. 1 , the axial force applied by the press tool (not shown) causes a compressive force on swage rings  30  and  32 . This force urges swage rings  30  and  32  inward toward the center of the sleeve  20 . This movement causes the inner ramp  70  to contact protrusion  40  and provide a continuous force against protrusion  40  as the sleeve moves towards the shaft shoulders  50  and  52 .  FIGS. 2 and 3  illustrate an additional embodiment of conduit  10  with fully engaged swage rings  30  and  32 . As illustrated in  FIG. 2 , the force exerted on the protrusion  40  by the inner ramp  40  pushes the inner ramp  70  over and to the inward side of protrusion  40 . As shown in  FIG. 3 , such force causes a deformation of the sleeve  20 , including specifically areas  104  and  106  on opposite sides of the protrusion  40 . This propels a deformation area  104  of the sleeve  20  into the space  100 . The unoccupied areas of  100  and  102  allow unrestricted buckling or deformation of the areas  104  and  106 . The compressive force applied by the swage rings  30  and  32  causes the inner damping ring  42  ( FIGS. 2 and 3 ) to bite into the outer surface of pipe  14 , creating a seal between the sleeve  20  and pipe  14 . 
         [0017]    Referring again to unengaged swage rings  30  and  32  illustrated in  FIG. 1 , as inner clamping ring  42  continues to bite into the pipes  12  and  14 , swage rings  30  and  32  are further urged inward relative to the main body  20  along line  45  until at least the inner land  74  makes contact with the protrusion  40 . As shown in  FIG. 2 , only inner ramp  70  and inner land  72  engage protrusion  40 . The axial pressure provides a continuous force on the sleeve  20 . As illustrated in  FIG. 3 , such force causes a deformation of the sleeve  20 , including specifically areas  104  and  106  on opposite sides of the protrusion  40 . This propels a deformation area  104  of the sleeve  20  into the space  100 . The unoccupied areas of  100  and  102  allow unrestricted buckling or deformation of the areas  104  and  106 , as shown by  FIG. 3 . The compressive force applied by the swage rings  30  and  32  causes the inner clamping ring  42  ( FIG. 2 ) to bite into the outer surface of pipe  14 , creating a seal between the sleeve  20  and pipe  14 . The downward biting force of outer clamping ring  44  continues as the swage ring  32  is further urged relative to the main body  20  until the inner land  76  is placed above and engages the terminal end of sleeve  20 . Only ramp  43  and land  44  engage such end of the main body  20  where the outer clamping ring  44  is located. 
         [0018]    As illustrated in  FIGS. 1-3 , the outer ramp  72  engages the end of main body  20  after the inner ramp TO engages the protrusion  40  such that the outer clamping ring  44  bites into the outer surface of pipe  14  after the inner clamping ring  42 . Specifically, as the swage ring  32  (or  30 ) presses inward, the inner clamping ring  42  begins biting into the pipe  14  first, followed by the biting of outer clamping ring  44 . Pressure from swage ring  32  then causes the inner clamping ring  42  and the outer clamping ring  44  to simultaneously bite into the outer surface of pipe  14 . The spaces  100  and  102  provide discontinuous contact between the sleeve  20  and the exterior surface of pipe  12  and  14 . In particular, spaces  100  and  102  allow unrestricted deformation or buckling in the areas  104  and  106  ( FIG. 3 ). Moreover, restriction of such deformation and buckling could otherwise result in a kickback force that tends to force the clamping ring  42  away from the pipe  14 . In addition, continuous application of a force on the protrusion  40  by the ramp  70  during biting of the outer clamping ring  44  helps to keep the inner clamping ring  42  pressed against the pipe  14  in the presence of any kickback force. The biting of the clamping rings  42  and  44  provides a sequential gas- and liquid-tight seal and locks the conduit assembly  10  onto the pipes  12  and  14  with a minimal loss of compression force. Kickback of the first clamping ring (inner clamping ring  42 ) is prevented in part because of a continuous load force being applied to the inner clamping ring  42  by the ramp  70  while the outer ramp  72  is causing the outer clamping ring  44  to bite into the pipe. Retraction of the assembly is prevented even under high pressure applications or with excessive vibrations. 
         [0019]    Referring again to  FIG. 1 , the axial force provided by the press tool (not shown) urges swage rings  30  and  32  inward towards the protruding portion of stop  22  where they contact shaft shoulders  50  and  52 . As previously detailed, step  62  of sleeve  20  is dimensioned to receive retaining ring  60  of the swage ring  30 . Swage ring  32  has similar corresponding structure. As shown in  FIGS. 1 and 2 , the surface  64  of step  62  and the surface  66  of retaining ring  60  are sloped or shaped in a complementary manner and provide complementary conformations. In one embodiment, surface  64  is concave (slopes downward and then upward) while the surface  66  convex (protrudes outward). It will be understood by one of skill in the art that other complementary shapes are contemplated by the present disclosure. In this embodiment, the convex contour  66  of the retaining ring  60  corresponds to the concave shaped surface  64  of step  62 . These two complementary shaped surfaces fit snugly together and lock into place. As a result, a tight tit occurs between the retaining ring  60  and the step  62 , Because the retaining ring  60  and the step  62  are securely held in a locked position, movement of the swage ring  30  in an outward direction along line  45  is prevented. This reduces the possibility of a reduction of the force exerted onto the inner clamping ring  42  and outer clamping ring  44  by the swage rings  30  and  32 . Specifically, the locking nature of the retaining ring  60  and the step  62  retains the swage rings  30  and  32  in an engaged position (illustrated in  FIGS. 2 and 3 ) and prevents disengagement (illustrated in  FIG. 1 ) of the clamping rings  42  and  44  from the exterior surface of pipes  12  and  14 . The secure connection between the retaining ring  60  and the step  62  allows assembly  10  to withstand greater external forces, such as vibrations, that otherwise could result in loosening and eventual failure of the connection. 
         [0020]    The assembly  10  of the present disclosure joins pipes of varying construction and with a variety of sizes. The assembly  10  eliminates the need for soldering, welding, bonding or the use of screws, reducing installation time and eliminating any change in the inner pipe diameter. The conduit  10  may also be installed in any medium and at any temperature because it is a metal fitting. Greater installation force may be used to connect conduit  10  without the threat of loss of load force or kickback of the sequentially biting teeth. Loss of load force is also prevented because the conduit  10  provides for a secure locking mechanism which prevents retraction of the swage rings  30  and  32  in a direction away from the sleeve  20 . This reduces the need for additional or repeated tightening steps, cutting installation and supply costs. In additional, the absence of welding or bonding prevents the accumulation of weld slag inside the pipes, eliminating the need for pipes pigging, pickling, flushing or other expensive post-installation steps.