Abstract:
A nut and tail assembly and method of manufacture including a nut having a first end and an inward flange at the other end, a longitudinal cylindrical hollow body having a first end and a second end at which is located an outstanding flange and a circular longitudinal sleeve. The sleeve extends along said sliding surface and has a flange at a first end abutting against the body flange. A stop is located between the ends of the body and defines a cavity sliding surface generally parallel to the longitudinal body between the stop and flange. The nut inward flange extends into the body cavity and is of large enough diameter to be able to slide on said body sliding surface, but small enough to be held within said cavity defined between said stop and sleeve flange. Projections on the sleeve flange assist in locating the sleeve relative to the nut during the moulding process.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a divisional of U.S. patent application Ser. No. 10/494,496 filed May 4, 2004, that claimed priority from Patent Cooperation Treaty Application No. PCT/AU03/00651, which had an international filing date of May 29, 2003; which in turn claimed priority from Australian Application Serial No. PS  2671 , which was filed May 31, 2002; the entire specifications of these aforementioned applications being expressly incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Technical Field  
         [0003]     The present invention relates to a pipe or conduit assembly or fitting including an outer member rotatable over an inner member, said inner member including a rigid outer sleeve extending over a part of said tail assembly, and to a method of production thereof including any dies for the production of such a fitting.  
         [0004]     2. Background Information  
         [0005]     Nut and tail assemblies are typically moulded from plastics material, the typical assembly including a tail having an external thread at one end and an outstanding flange or lip at the other end with a stem extending therein between, said assembly also including a nut having an inturned flange that bears against the back of the tail outstanding flange and is arranged to firmly retain the assembly to a male threaded fitting. These fittings can be made many ways such as spin-welding or two-part operations. Other conduit fittings such as barrel unions, and fittings on the ends of valves can be made by the same methods.  
         [0006]     In a previous patent by the same applicant, Australian Patent 579,134 (filed as, Serial No. AU198538626), the contents of which are expressly incorporated by reference herein, there was disclosed both a method and a fitting manufactured by said method that greatly simplified the construction of such a fitting having a nut and tail of moulded plastics material. The method included placing the nut in a die and moulding the tail with the nut in one single die operation so that the tail outstanding flange was moulded within the body of the nut, the nut inturned flange located behind the outstanding flange of the tail. Such a method and fitting greatly simplified the then known manufacturing processes.  
         [0007]     Although the fitting described in the aforementioned patent has been found to work satisfactorily in most circumstances, it has been found that lateral twisting and bending of such a fitting can cause failure in the fitting, especially in the body of the tail or stem immediately adjacent the inturned flange of the nut. In situations where such a fitting may be prone to lateral forces, this type of fitting is therefore unsuitable.  
         [0008]     It is an object of the present invention to propose improvements in such a fitting and construction thereof whereby there is proposed a fitting having a nut, a tail of moulded plastics material, a sleeve extending at least partially over said tail and formed of a resilient material.  
         [0009]     It is a further object of the present invention to provide for improvements in the construction of such a fitting or at least provide the public with a useful alternative.  
       SUMMARY OF THE INVENTION  
       [0010]     Therefore in one form of the invention there is proposed a nut and tail assembly including:  
         [0011]     a longitudinal cylindrical hollow body having a first end, said body including an outwardly extending stop located inwardly from said first end, said body further having an outstanding flange at the second end thereof, said stop and flange defining therein between a cavity sliding surface generally parallel to the longitudinal body;  
         [0012]     a circular longitudinal sleeve extending along said sliding surface;  
         [0013]     a nut having a first end, and an inward flange at the other end, said nut inward flange extending into said body cavity and being of a diameter to be able to slide on said body sliding surface.  
         [0014]     In a further form of the invention, there is proposed a nut and tail assembly including:  
         [0015]     a longitudinal cylindrical hollow body having a first end, said body including an outwardly extending stop located inwardly from said first end, said body further having an outstanding flange at the second end thereof, said stop and flange defining therein between a cavity sliding surface generally parallel to the longitudinal body;  
         [0016]     a circular longitudinal sleeve extending along said sliding surface and having a flange at a first end thereof, said flange abutting against said body flange;  
         [0017]     a nut having a first end, and an inward flange at the other end, said nut inward flange extending into said body cavity and being of a diameter to be able to slide on said body sliding surface.  
         [0018]     In preference said body first end includes a plurality of external threads. Of course, other types of connections include snap-on type fitting could well be employed.  
         [0019]     Preferably said nut includes a plurality of internal threads at said first end.  
         [0020]     In preference, said sleeve other end extends into said body. It is therefore anchored into the body and is integral with the body.  
         [0021]     In preference, said sleeve other end includes at least one groove wherein said groove assists in longitudinally anchoring said sleeve in said body.  
         [0022]     In preference said body is manufactured from polymeric plastic. This enables it to be moulded in a die operation.  
         [0023]     In preference said sleeve is manufactured from metal. This may include various metals such as brass that then give the fitting strength against bending and twisting.  
         [0024]     In preference said sleeve includes projections extending longitudinally outwardly from said flange. These projections help locate the sleeve before moulding.  
         [0025]     In preference said projections are located symmetrically and circumferentially on said flange.  
         [0026]     In preference there are at least four said projections. These projections may be small pin-like projections although they may equally well be blocks.  
         [0027]     Preferably located in between said sleeve and said external threads, is a torque converter to assist in controlling the rotational motion of the body including said tail and sleeve.  
         [0028]     In preference the assembly includes a gasket housed within said nut and abutting against said body outstanding flange.  
         [0029]     In yet a further form of the invention there is proposed a method of manufacture of a fitting with an inner member having a sleeve, and an outer member that is rotatable over said sleeve, the method including the steps of: 
    (a) making the outer members to a shape that includes a radially inturned annular flange at one end and an axially extending portion having an internal thread,     (b) placing a sleeve within said outer member, said sleeve having a radial outwardly extending annular flange, said sleeve flange abutting against said outer member flange and extending longitudinally away from said internal thread,     (c) positioning the outer member and sleeve onto an axially aligned male portion of a moulding die and within two female portions, said male portion including a plurality of locating pins engaging said sleeve,     (d) closing the moulding die thereby placing the outer member and sleeve in their final position and establishing a moulding cavity within which is located the outer member and sleeve, part of the surface of said cavity defined by the outer surface of the sleeve annular flange, part of which is defined by the sleeve inner surface, part of which is defined by inner surfaces of the female die portions, and part of which is defined by surfaces of the male die portions.    
 
         [0034]     In preference the method of manufacture includes making the outer member by moulding or machining operations.  
         [0035]     In preference in the method of manufacture, the moulding cavity is so shaped that the length of the inner member not adjacent the sleeve flange is longer to allow for shrinkage of the inner member during cooling.  
         [0036]     In a still further form of the invention, there is proposed a die for moulding of the tail of a nut and tail assembly having a sleeve, said die including two separable complementary female die portions having inner surfaces defining a recess, and at least one male die portion characterized in that the die moulding cavity is defined partly by the outer surface of the annular flange of said sleeve when inserted into said recess, partly by the recess surfaces of the female die members, partly by the inner surface of said sleeve, and partly by a surface of the male die portion.  
         [0037]     In a yet further form of the invention there is proposed a fluid connector including:  
         [0038]     a longitudinal hollow body having a first connection means at one end thereof, an outward flange at the other end thereof, and a stop located in between said ends;  
         [0039]     a cylindrical sleeve located on top of said body between said outward flange and said stop; the diameter of said outward flange and said stop being greater than the diameter of the body between the two;  
         [0040]     a nut having a second connection means at one end and a radially extending inward flange at the other end, said inward flange located between and of a smaller diameter than said body stop and outward flange.  
         [0041]     In preference said nut inward flange diameter is only slightly larger than the diameter of the sleeve enabling said nut to slide along said sleeve.  
         [0042]     In preference said first connection means are external threads and said second connection means are internal threads. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0043]     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention, and, together with the description, serve to explain the advantages and principles of the invention.  
         [0000]     In the drawings:  
         [0044]      FIG. 1  is a perspective view of a moulded fitting embodying the present invention and including a nut, tail and sleeve;  
         [0045]      FIG. 2  is a perspective view of the sleeve of  FIG. 1 ;  
         [0046]      FIG. 3  is a cross-sectional view of the moulded fitting of  FIG. 1  embodying the present invention;  
         [0047]      FIG. 4  is a longitudinal cross-sectional view illustrating the die used in the manufacture of the fitting or conduit;  
         [0048]      FIG. 5  is a cross-sectional view of a moulded fitting having an alternate configuration of a sleeve, according to the present invention;  
         [0049]      FIG. 6  is a perspective view of a sleeve having yet a further alternate configuration and including integrally formed locating projections;  
         [0050]      FIG. 7  ( a ) is a partial cross-sectional view of the sleeve, nut and tail of  FIG. 5  before the moulded plastic has cooled; and  
         [0051]      FIG. 7  ( b ) is a partial cross-sectional view as in  FIG. 7 ( a ) but when the moulded plastic has cooled causing shrinkage of the plastic. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0052]     The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.  
         [0053]     Referring to the Figures there is shown a fitting  10  including a nut  12 , tail  14 , and a sleeve  16 . Nut  12  includes a body  18  having internal threads  20 , bore  22  at one end, and a radially inturned flange  24  at the other end. The internal threads  20  are adapted to engage external threads of a suitable device such as a water meter or similar device. An O-ring, washer, or gasket  26  is used within the nut  12  for sealing engagement with such device.  
         [0054]     The outer surface of the nut  12  is of a non-circular shape  28  to enable a tool, such as a wrench, to be used to tighten the nut  12  upon application.  
         [0055]     The tail  14  includes a longitudinal body  30  having external threads  32  at one end thereof, an outwardly extending integrally formed torque converter  34  having a polygonal outer surface  36  assisting engagement of the converter  34  with an appropriate tool such as a wrench (not shown) that can be used to rotate the tail  14 .  
         [0056]     The tail  14  includes a stem  38  extending from the torque converter  34  longitudinally away from the external threads  32  and having an outwardly extending radial flange  40 . The flange  40  may include a shoulder (not shown) for retention of the gasket  26 .  
         [0057]     The sleeve  16  extends along the outer surface  42  of the tail  30  between the torque converter  34  and the flange  40 , the sleeve  16  at one end including radially outward flange  44  that is correspondingly shaped to nestle in flange  40  of the tail stem  38 . The other end of the sleeve  16  extends into the tail body  30  under the torque converter  34 .  
         [0058]     The diameters of the stem  38 , sleeve  16 , and the nut flange  24  are chosen so that the nut  12  can freely slide alongside the sleeve  16 . That is, the inner diameter of the nut flange  24  is greater than the outer diameter of the sleeve  16 . At the same time, the outer diameter of the outward flange  44  is greater than the inner diameter of the nut flange  40  so that the nut  12  remains captured and can slide alongside the stem  16  between the torque converter inner surface  46  and the inner surface  48  of the outward flange  44  of the sleeve  16 .  
         [0059]     In the method of manufacture of the nut and tail assembly  10 , location pins  50  are used to hold the sleeve  16  in place before moulding to thereby lock the sleeve  16  in position on the stem  38  with the sleeve  16  partially extending into the tail  30 . As illustrated in  FIG. 1 , four pins  50  may be used, although it is to be understood that more or less may be used depending on the size of the sleeve and the assembly. It is to be understood that the pins  50  may be integral with the sleeve  16 , although they are typically part of the die arrangement. If part of the die arrangement, as the pins are removed, small apertures are left in the flange  40  of the stem  38 .  
         [0060]      FIG. 4  illustrates a die  52  that is used in the method of manufacture of the nut and tail assembly  10  according to the present invention. The die  52  is provided with four parts, a front male portion  54 , a rear male portion  56  that, upon die closure, abuts the front male portion  54 , and two female portions  58  and  60  which, upon closure, abut each other on an axial plane  62 .  
         [0061]     When the female portions  58  and  60  are closed they define a cavity or recess  64 .  
         [0062]     In the manufacture of assembly  10 , however, sleeve  16  is firstly inserted into nut  12  so that flanges  40  and  44  abut against each other. The nut  12 , with the sleeve  16  extending outwardly is then positioned in the front male portion  54  of the die  52  that includes locating pins  50 . The locating pins  50  are advantageous for a number of reasons. Firstly, they ensure that the sleeve longitudinal axis is generally parallel to the axis  62 . They also ensure that during the moulding operation the nut flange  24  abuts the sleeve flange  44  so that the determined thickness of the moulded plastic on the sleeve flange  44  is achieved. Otherwise, if the sleeve  16  were to move axially toward the nut flange  24  during the moulding operation this thickness may be reduced leading to an unacceptable assembly where the sleeve is not supported within the tail  30 .  
         [0063]     When the female portions  58  and  60  are then closed they bear against the outer surfaces of the nut  12  and a portion of the sleeve  16  establishing a moulding cavity  66 . The moulding cavity  66  is therefore defined by the surface or boundary of recess  64 , partially by the front and rear male portions  54  and  56  adjacent their mutual abutment zone, partially defined by the inner surface of the annular nut flange  24  and partially defined by the sleeve  16 .  
         [0064]     The die  52  is typically formed from tool steel and is provided with cooling conduits  68  therein. The die cavity, in which the tail forms flange  40 , may have an additional shoulder recess (not shown) for retention of a sealing ring, typically an O-ring (not shown). In the case of an O-ring, the tail may also include an overhang to capture the O-ring in position (not shown).  
         [0065]     Fluent plastics material is injected into the die cavity  66 . However, the nut  12  is cold, and the die portions are rapidly cooled by the cooling effect of the fluid flowing through the conduits  68 . The die portions are then separated, and the nut  12  and the sleeve  16  remain captive on the front end of the tail  14  due to the outstanding flange portions  24  and  44  of the nut  12  and sleeve  16  and the outstanding flange portion  40  of the nut stem  38  that, by its moulding, is of a complementary shape to the inner surface of the nut and sleeve flange  24  and  44 . The sleeve  16  is also captive since its other end, which is the end opposite to its flange, is now captured within the stem  38  of the tail  30 .  
         [0066]     It will now be readily apparent to the reader that the present invention ensures that there is provided a nut and tail assembly that has a sleeve that improves upon the integral strength of the assembly. Further, the process of manufacture that includes the pins ensures that the assembly can be repeatedly made whilst ensuring quality standards.  
         [0067]     The sleeve is typically made from metal such as brass that has the necessary strength to provide for support of the rest of the fitting.  
         [0068]     In an alternative embodiment of the present invention and as illustrated in  FIG. 5  is an assembly including sleeve  16 , the sleeve at its outer end opposite to flange  44  including annular grooves  70 . These grooves  70  located at the end of the sleeve opposite to the flange  44  are embedded within the stem  38  of the tail  14 . During the moulding operation, the grooves  70  are filled with plastic that, when cools, integrally locks the sleeve  16  to the stem  38  thereby providing additional support against longitudinal movement between the two. Of course, instead of grooves, the sleeve may very well have projections around which forms the body during moulding.  
         [0069]     In the embodiment discussed so far, locating pins  50  were positioned on the die. However, not only do the locating features not need be pins, but they may in fact be projections that are integrally formed in the sleeve  16 .  
         [0070]     Illustrated in  FIG. 6  is such an arrangement where locating blocks projections or blocks  74  are part of the sleeve  16 . This may occur, for example, where one is using suitably strong plastic material, not necessarily metal, the sleeve  16  also being able to be produced as part of the moulding operation.  
         [0071]     One of the problems often encountered in moulding plastics is shrinkage. Where the plastic shrinks in one direction and does not encounter any resistance, only its size is reduced. However, the addition of a sleeve results in the plastic encountering resistance when shrinking in the longitudinal direction of the stem. For that reason, it is advantageous to construct a die so that when the plastic is still hot, the inner diameter of the stem  74  projects further outwardly into the nut  12  than the flange  40 , as shown in  FIG. 7 ( a ). As the plastic cools, this portion  74  of the stem  38  retracts into the tail  30  whilst the flange  40  of the tail  30  is prevented from retracting due to the sleeve flange  44 . Since the amount of shrinkage can be predetermined, moulding a tail whose shape whilst hot is as in  FIG. 7 ( a ) can result in the cooled shape being as illustrated in  FIG. 7 ( b ).  
         [0072]     Those skilled in the art will now appreciate that the nut  12  can slidably move alongside the outer surface  42  of the sleeve  16 . The sleeve  16  is typically made from metal such as brass, thereby providing strength to the assembly against any lateral forces.  
         [0073]     It has been found that there is no tendency for adhesion or fusion to occur between the surfaces of the nut, sleeve, and tail, and upon shrinkage of the tail under cooling, the nut has been found to be freely rotatable about the tail. Since the surfaces are generally circular, there is very good surface to surface contact as the nut is tightened when in use.  
         [0074]     It is to be understood that reference to flange through the description typically includes an annular flange.  
         [0075]     The present invention provides a nut and tail assembly that having a resilient sleeve, provides an assembly that withstands lateral forces whilst being manufacturable without expensive weld and inspection operations, at the same time reducing overall cost.  
         [0076]     Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.