Abstract:
Apparatus for joining a first conduit to a second conduit comprising a first coupler for attachment to an end of the first conduit, a second coupler for attachment to an end of the second conduit and for engagement to the first coupler, and a snap-fit fastener for fastening the first coupler to the second coupler. The snap-fit fastener is arranged in at least two portions to fit around the periphery of the first and second couplers when the first and second couplers are engaged. The apparatus enables relative movement between the first coupler and the second coupler.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority from Australian Provisional Patent Application No 2007901708 filed on 30 Mar. 2007, the content of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    This invention relates to an apparatus used to join conduits and more particularly relates to apparatus for joining a pair of pipes. 
       BACKGROUND OF THE INVENTION 
       [0003]    Presently conduits, such as pipes are joined either by welding or gluing the ends of the pipes to each other. Other pipe joining arrangements have used a clamp or collar at the junction between the two pipes which ultimately have to be welded or glued or otherwise adhered in some fashion to ensure the pipes remain attached. 
         [0004]    When vibrations occur due to passing fluid, either liquid or gas, within the pipes, sometimes under pressure, this can weaken and in some instances rupture the join between the pipes as there is no possible movement between the pipes to counteract or make allowances for such vibrations. 
         [0005]    It is desirable to provide a pipe joining apparatus that enables an amount of movement between the pipes or conduits to be joined so that the join can absorb any amount of vibration that is present in transporting the fluid within the pipes through the join. 
         [0006]    The present invention seeks to address one or more of the above disadvantages by providing such a conduit joining apparatus. In some instances it reduces the amount of welding and gluing that needs to be done with existing pipe joining apparatus and methods. It is also desirable to provide joining apparatus that is easier to install than previous arrangements and to be able to reuse some or all of the joining apparatus. 
       SUMMARY OF THE INVENTION 
       [0007]    According to a first aspect of the invention there is provided apparatus for joining a first conduit to a second conduit comprising: 
         [0008]    a first coupler for attachment to an end of the first conduit; 
         [0009]    a second coupler for attachment to an end of the second conduit and for engagement to the first coupler; 
         [0010]    a snap-fit fastener for fastening the first coupler to the second coupler, the snap-fit fastener arranged in at least two portions to fit around the periphery of the first and second couplers when the first and second couplers are engaged; 
         [0011]    wherein the apparatus enables relative movement between the first coupler and the second coupler. 
         [0012]    The fastener preferably is able to move relative to each of the first and second couplers. 
         [0013]    Preferably the conduits are cylindrical and each of the first coupler, second coupler and fastener are substantially circular in axial cross-section. Therefore each of the portions or halves of the fastener, denoted first half and second half, are preferably substantially semi-circular in axial cross-section. 
         [0014]    The first coupler is preferably a female coupler for receiving the second coupler which is preferably a male coupler. Each coupler may have an internal circumferential step to set a limit for abutment of the respective end of each conduit as the conduit is attached to the coupler. The conduit may be attached to the respective coupler by any means such as welding, soldering, gluing or by co-operating threaded portions on the conduit and on the coupler. 
         [0015]    Where the fastener is formed in two substantially identical halves, it preferably has two locking arrangements that snap-fit the two halves of the fastener together. Each locking arrangement preferably comprises a male component and a female component, such that at one end of each half there is disposed a female component and at the other end of each half there is disposed a male member. Thus the male member of one half interlocks with a female member of the other half to snap-fit and lock the fastener around the couplers. The female member may have a slot substantially shaped to fit the corresponding male member. The male member may be shaped in a T-formation or an arrowhead or any other shaped projection. 
         [0016]    In order to apply the fastener to the engaged couplers, the two halves are locked with one of the locking arrangements. Thereafter the fastener is applied by hand or fingers of a user around the periphery of the engaged couplers until the male member of the second locking arrangement is next to a corresponding female member. Pressure is applied to the male member to ease it over or under the female member until the male member snap-fits into the slot of the female member. 
         [0017]    The apparatus may further comprise a locking pin adapted to have each end thereof fit into one or both of the female members of the two locking arrangements and traverse the female members so as to prevent separation of each locking arrangement due to vibrations or pressure due to the transport of fluid within the conduits. 
         [0018]    The second male coupler preferably has one or more circumferential grooves for housing a respective sealing ring to prevent escape of any fluid from the first or second conduits and to absorb any vibrations created by the passage of fluid within the first and second conduits. 
         [0019]    When engaged, the first and second coupler preferably present an exterior surface that has a raised portion for co-acting with the interior surface of the fastener. The fastener preferably has a depending foot portion formed at each circumferential edge of the fastener, with each depending foot portion engaging a respective edge of the raised portion and a respective shoulder on each of the first and second couplers. This assists in the fastener securing the first coupler to the second coupler. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    A preferred embodiment of the invention will hereinafter be described by way of example only, with reference to the drawings wherein: 
           [0021]      FIGS. 1 ,  1 B and  1 D are exploded perspective views of the conduit joining apparatus including first and second couplers and a snap-fit fastener; 
           [0022]      FIGS. 1A and 1C  show the conduit joining apparatus with the fastener securing the first coupler to the second coupler; 
           [0023]      FIG. 1E  shows the conduit joining apparatus of the previous Figures as used and fitted to join a pair of conduits; 
           [0024]      FIGS. 2A to 2D  are respectively front, plan, underneath and side views of the conduit joining apparatus with the fastener securing the first coupler to the second coupler; 
           [0025]      FIGS. 3A to 3C  are sectional views along line A-A of  FIG. 2A  of different embodiments of the apparatus; 
           [0026]      FIG. 4  is a perspective view from below of a portion of the snap-fit fastener; 
           [0027]      FIG. 5  is a perspective view from above of a portion of the fastener which is adapted to interact and engage in a snap-fit connection with the portion shown in 
           [0028]      FIG. 4 ; 
           [0029]      FIG. 6  is a perspective view from above of a locking pin for ensuring that the snap-fit fastener does not separate under extreme pressure; and 
           [0030]      FIG. 7  is a perspective view from above showing the locking pin as fitted when the snap-fit fastener is in a usable form. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0031]    Referring to  FIGS. 1 ,  1 A to  1 E and  2 A to  2 D there is shown apparatus  2  with the components of apparatus  2  separated. The apparatus  2  includes a first coupler  4  which is a female coupler, a second coupler  6 , being a male coupler, and a snap-fit fastener  8 . The first coupler  4  has a chamfered circumferential ring or edge  10  that is adapted to receive internally the end of one conduit, such as a pipe and similarly the second coupler  6  has a chamfered circumferential ring or edge  12  which is adapted to receive internally the end of a second conduit such as a pipe. Each conduit is respectively adhered to the respective coupler by suitable means, such as welding, soldering or gluing. The coupler  4  has an internal step  14  that abuts against the end of the respective pipe or conduit  28  and sets a limit beyond which the pipe  28  cannot move. Second coupler  6  also has a step  16  against which the end of its respective pipe  30  abuts and sets a limit beyond which the pipe  30  cannot move. 
         [0032]    The first coupler  4  receive the second coupler  6  whereby the inner circumferential edge  18  of coupler  6  abuts against the inner surface of step  14  in first coupler  4 . Also, the inner edge  20  of first coupler  4  abuts adjacent to the inner surface of ridge  22  of the second coupler  6 . After the first and second couplers  4  and  6  are brought together in close contact a snap-fit fastener  8  provides a compression fitting around the two couplers in order to keep the couplers together and therefore the respective pipes are joined to each other. A small gap exists between the circumferential edge  18  of coupler  6  and the inner surface of step  14  and also between the inner surface of the ridge  22  and the inner circumferential edge  20 . This allows a small amount of movement between each of the couplers  4  and  6  so that any vibration that is caused by fluid passing through the joined pipes does not create pressure on the join, as movement is possible between the couplers  4  and  6  and therefore between the joined pipes. 
         [0033]    A primary sealing ring  24  fits into a groove  26  on second coupler  6  and is more clearly seen in cross-section in  FIG. 3A . The snap-fit fastener  8 , which acts as a retaining ring to retain the first coupler  4  to the second coupler  6 , is formed by two semi-circular substantially identical portions, termed first and second halves  9  and  11 . Each of the halves  9 ,  11  are joined by respective interlocking members, whereby a projection is adapted to fit into a slot in a snap-fit arrangement. Preferably each half of the snap-fit fastener  8  has at one end a male member and at the other end a female member so that the male member of one half is adapted to fit the female member of the other half. 
         [0034]    With reference to  FIG. 1E  (and to  FIGS. 1A and 1C ) there is shown the conduit joining apparatus  2  in use whereby the first coupler  4  has been fitted to second coupler  6  with the primary sealing ring  24  fitted into the groove  26 . Thereafter the two halves  9 ,  11  of the snap-fit fastener  8  have been locked together through their respective male and female members. Shown in phantom in  FIG. 1E  is a first pipe  28  which is secured to first coupler  4  with chamfered or slanted outer edge  10  being external to the periphery of the conduit  28  and with the circumferential edge of the conduit  28  abutting against the step  14 . It is thereafter welded to the coupler  4  or otherwise secured such as by gluing. Similarly, conduit  30  is fitted to coupler  6  whereby the outer edge of the conduit  30  abuts adjacent the inner step  16  within coupler  6  and with the chamfered or slanted external edge  12  of coupler  6  being external to the conduit  30 . The conduit  30  is then secured by welding or gluing to the coupler  6 . The conduit  28  and coupler  4  are then fitted to coupler  6  and conduit  30 . Thereafter, the snap-fit fastener  8  is fitted over the couplers  4  and  6  whereby the internal surface of the snap-fit fastener  8  contacts the outer surface of the female first coupler  4  and ridge  22  of coupler  6 . 
         [0035]    Referring to  FIGS. 3A to 3C  there is shown, in cross-section, each of the couplers  4  and  6  fitted to one another and secured by snap-fit fastener  8 .  FIG. 3A  shows the sealing rings  24  and  50  fitted within square-profiled grooves  26  and  52 .  FIG. 3B  shows the square-profiled grooves  26  and  52  without the sealing rings  24  and  50 .  FIG. 3C  shows grooves  26  and  52  having a substantially semi-circular profile without the sealing rings  24  and  50 . With particular reference to  FIG. 3A , the snap-fit fastener  8  has a pair of feet  32  and  34 , formed at each circumferential edge of the halves  9  and  11  of fastener  8 , that respectively rest or abut against shoulders  36  and  38  of each of the couplers  4  and  6 . The inner surface  40  of the snap-fit fastener  8  snugly abuts against the outer raised flat surface  42  of coupler  4  and briefly contacts the top portion of ridge  22  of coupler  6 . The profile of the inner surface  40  closely follows each of the inclines  44  and  46 . The feet  32  and  34  of the snap-fit fastener  8  combine to keep the couplers  4  and  6  in a relatively stationary lateral position. Each of the couplers  4 ,  6  are still able to move slightly in a radial position with respect to each other. Thus, the fastener  8  can move circumferentially around the couplers  4  and  6  and likewise the couplers  4  and  6  can move circumferentially with respect to each other. This is enabled via a small gap between edge  18  of coupler  6  and the inside edge  15  of step  14  and also between the edge  20  and the inside edge  48  of ridge  22 . 
         [0036]    As mentioned previously there is a primary sealing ring  24  located in groove  26  of coupler  6 . A further secondary sealing ring  50  exists within groove  52  of coupler  6  with each of the grooves  26  and  52  being separated by a ridge  54 . The profile of the grooves  26  and  52  may be any particular shape, such as square as shown in  FIGS. 1D ,  3 A and  3 B or can be substantially semi-circular as shown in  FIGS. 1B and 3C . The sealing rings  24  and  50  also abut against an inner surface  43  of the coupler  4 . Thus, any fluid leakage that occurs between the pipes  28  and  30  will be sealed by primary sealing ring  24  and backed up by secondary sealing ring  50  such that there is no escape of the fluid between the gap created between edges  20  and  48 . 
         [0037]    The internal surface  55  and  56  respectively of the couplers  4  and  6  may be threaded so that they engage corresponding end threaded portions of the pipes  28  and  30 . Thus, as an alternative to welding, the pipes may be threaded into each of the couplers. The thickness of each of the conduits  28  and  30  substantially match the thickness of steps  14  and  16  so that a generally smooth surface is provided internally for a smoother flow of the fluid through the conduits  28  and  30 . 
         [0038]    With references to  FIGS. 4 and 5 , there is shown a pair of members  58 ,  60  that form one of two locking arrangements between the two halves  9 ,  11  of the snap-fit fastener  8 . In  FIG. 4  there is shown an end of one half  9  that has a projection or male member  58  which is adapted to be received in the female member  60  having slot  61  located at one end of the other half  11  of the snap-fit fastener  8  as shown in  FIG. 5 . Thus, as is more clearly shown in  FIG. 7  the T-portion of the male member  58  is designed to fit snugly into a corresponding T-slot or opening in the female member  60 . Thus, the inner sides  62  and  64  of the member  58  abut against respective side walls  66  and  68  of female member  60 . The locking mechanism defining the snap-fit connection is shown in  FIG. 7 . Each half is preferably of aluminium and has sufficient flex or tension to enable the snap-fit connection. 
         [0039]    With reference to  FIGS. 6 and 7  there is shown a transverse locking pin  70  that fits within respective apertures  72 ,  74  in the side walls adjacent the end having the female member  60  of one or both of the halves  9 ,  11 . The pin  70  is designed to keep each of the locking members  58  and  60  together and to prevent them from coming apart particularly due to extreme pressure brought about by the transportation of pressurised fluid within the pipes. 
         [0040]    It is to be noted that the locking arrangement between the members  58  and  60  may be of any particular configuration that enables each of the halves to be locked to one another. Generally, these will comprise a male member and a female member that may be differently shaped. Apertures such as  74  and  76  shown in  FIG. 1  may be provided in the fastener  8  primarily to reduce the weight of the fastener  8 . Each of the components, being the couplers  4  and  6  and the fastener  8  together with the locking pin  70 , may be made of a suitable metallic material, such as aluminium. The two halves  9 ,  11  of the fastener  8  are preferably made with tension such that each half is sprung to enable the snap-fit connection to take place in order to substantially prevent transverse movement between the couplers  4  and  6 . Other embodiments may include more than two portions that interlock through respective locking arrangements to form the fastener  8 . 
         [0041]    In order to assemble the apparatus the user attaches coupler  4  to a respective edge of pipe  28  and secures one to the other either through welding, gluing or by thread means. The same process is applied to coupler  6  to the end of a respective pipe  30 . The coupler  6  is then inserted, with the sealing rings  24  and optionally  50 , into coupler  4 . The fastener  8 , being formed in two portions in one embodiment, is locked in place at one junction between a male member and a female member and then made to encircle the exterior surface  42  of the coupler  4 . Due to the tension provided in the two halves of the fastener  8  the male member is forced to lift up over or under the leading edges of the female member until it is snap-fitted into its corresponding female member  60 . The pin  70  is then inserted into its apertures in place to hold the coupler  4  to the coupler  6 . In order to dismantle the apparatus  2  the reverse process is undertaken and can be assisted by using a screw driver or the like tool to be placed in the remaining section of the female member  60  not taken up by the male member  58 . Then the male member  58  is gently levered outwardly so that the male member  58  protrudes out of the female member  60 .