Abstract:
A fluid coupling assembly which has a novel female subassembly capable of receiving a male portion, the female subassembly being formed by spin welding two generally cylindrical plastic parts together, one of the parts being a quick connect end portion and the other part being the barb end portion. The female subassembly is provided with a key or keyway to prevent rotation, to mate with a corresponding key or keyway on the male portion to prevent false connections, and to act as a clear visual aid for orientation. In this design differing barb end portions can be secured to a common quick connect end portion.

Description:
TECHNICAL FIELD 
     The present invention relates to a fluid coupling assembly, and more particularly to a female subassembly which is capable of receiving a male portion, the female subassembly being formed by spin welding two generally cylindrical plastic parts together, one of the parts being a quick connect end portion which is provided with a key or keyway to prevent rotation, to prevent false connections, and to act a clear visual aid for orientation, and the other part being the barb end portion. 
     BACKGROUND OF THE INVENTION 
     Fluid coupling assemblies are well known in the art. One form of fluid coupling assembly is shown in U.S. Pat. No. 4,640,534. This design has become popular in the automotive industry. This design was originally made of machined metal parts. However, the auto industry is looking for parts that both cost less and weigh less. It is also known to use spin welding techniques when forming a fluid coupling such as that shown in U.S. Pat. No. 6,832,785. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a fluid coupling assembly which is less expensive than prior art fluid coupling assemblies. 
     It is a further object of the present invention to provide a fluid coupling assembly which will weigh less than prior art fluid coupling assemblies. 
     It is an additional object of the present invention to provide a fluid coupling assembly which can be readily made from plastic molded parts and which can be assembled together by spin welding. 
     These and other objects and advantages of the present invention will become apparent from a consideration of the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a sectional view through the quick connect end portion of the female subassembly of a first design of a fluid coupling assembly of this invention. 
         FIG. 2  is a sectional view through the barb end portion of the female subassembly of a first design of a fluid coupling assembly of this invention, the barb being shown broken off. 
         FIG. 3  is a sectional view of the quick connect portion and the barb end portion of the first design shown in  FIGS. 1 and 2  after the parts have been spun welded together. 
         FIG. 4  is a sectional view through the quick connect end portion of the female subassembly of a preferred design of a fluid coupling assembly of this invention. 
         FIG. 5  is a sectional view through the barb end portion of the female subassembly of a preferred design of a fluid coupling assembly of this invention, the barb being shown broken off. 
         FIG. 6  is a sectional view of the quick connect portion and the barb end portion of the preferred design of the fluid coupling assembly of this invention after the parts have been spun welded together. 
         FIG. 7  is a perspective sectional view of the parts shown in  FIG. 6 , the O-ring shown in  FIG. 6  not being shown in  FIG. 7 . 
         FIGS. 8 and 9  are side elevational view of the female subassembly parts before they have been spun welded together, the barb portion shown in  FIG. 9  having a large diameter single barb. 
         FIG. 10  is a side elevation view of a male portion of the fluid coupling assembly of this invention before it has been mated with the female assembly. 
         FIG. 11  is a side elevational view of the fluid coupling assembly after all parts have been assembled together. 
         FIGS. 12 and 13  show the fluid coupling assembly of this invention with 90° barbs at differing orientations with respect to the key and/or keyway. 
     
    
    
     DETAILED DESCRIPTION 
     The fluid coupling assembly of this invention, which is indicated generally at  10 , is best shown in  FIGS. 10 and 11 . The assembly includes as its principal components a male coupler indicated generally at  12 , and a two part female coupling subassembly capable of receiving the male coupler, the female subassembly being indicated generally at  14 . The female subassembly is formed of two principal components, a quick connect end portion and a barb end portion. 
     In  FIGS. 1-3  a first design of a fluid coupling assembly of this invention is illustrated. In this design the quick connect end portion is indicated  16  and the barb end portion is shown at  18 . These two parts are made of plastic materials which can be spun welded together, the weld being indicated at  20 . To this end, the quick connect end portion is provided with a reduced diameter end cylindrical portion  16 . 1 , and the barb end portion is provided with a mating cylindrical portion  18 . 1 . To weld the parts together one part is held stationary, for example the quick connect end portion  16 , while the other portion, for example the barb end portion  18 , is rotated and moved into the other portion as indicated by arrow  22 . Because the parts are designed to have a friction fit, sufficient heat will be developed during the rotation to melt adjacent parts. The mechanism which rotates and advanced the parts together has a suitable stop mechanism so that the parts will be in their desired relationship when the rotation is stopped. After rotation has stopped, the parts will cool down and the melted material will form a weld between the parts. It is particular advantage of this invention that a common quick connect portion may be used with differing barb ends, for example with a barb end having the barb shown in  FIG. 9 , one with the barb end as shown in  FIGS. 10 and 11 , or a barb end having a right angle barb as shown in  FIGS. 12 and 13 . Also, it is possible to orient the barb end to the male portion by use of interfitting parts such as keys and keyways as will be discussed below. 
     While the male portion is not indicated in  FIGS. 1-3 , it will be of the same general construction shown in  FIG. 10 , having a groove  12 . 1 , a frusto-conical portion  12 . 2  and a reduced diameter cylindrical portion  12 . 3 . When the male portion is being inserted into the female subassembly a spring clip, not shown, which is received in the clip slots  16 . 2  will initially slide over the frusto conical portion  12 . 2  during insertion. The spring clip may be of the design shown at  18  in U.S. Pat. No. 4,640,534. When the male member  12  is fully inserted, the spring clip will have a portion engaging the groove  12 . 1  to retain the male member  12  within the female portion, and the frusto-conical portion  12 . 2  of the male member will be bearing against a frusto-conical surface  16 . 3  of the portion  16 . At this time, the reduced diameter cylindrical portion  12 . 3  will be snugly received within a reduced diameter cylindrical portion  18 . 2  of the barb end portion  18 . In addition, the portion  12 . 3  will bear against an O-ring  24  to form a fluid tight seal. In the design shown in  FIGS. 1-3  the O-ring  24  is received in an O-ring gland. The gland is formed by an internal cylindrical surface  16 . 4  and a shoulder  16 . 5  of the quick connect end portion  16 , and also by an annular surface  18 . 3  of the barb end portion  18  when the barb end portion  18  and the quick connect portion are in their assembled position as shown in  FIG. 3 . As high pressure fluids typically enter the fluid coupling assembly  10  of this invention from the barb end side as indicated by the arrow  26 , there is a potential leak path through the weld  20  if the weld is not 100% continuous, a portion of the potential leak path being highlighted by the circle A. 
     A preferred design is shown in  FIGS. 4-11  where common parts have the same reference numerals. Thus, the quick connect end portion is indicated at  16 , the spring clip receiving slots at  16 . 2 , the frusto-conical surface at  16 . 3 , and the shoulder at  16 . 5 . Also, the barb end portion is indicated at  18 , the reduced diameter cylindrical portion at  18 . 2 , and the annular surface at  18 . 3 . The weld is shown at  20 , and the O-ring is also indicated at  24 . This design differs from that shown in  FIGS. 1-3  in that the leak path to the weld  20  is from the low pressure quick connect portion  16  rather than from the high pressure barb portion  18 , a portion of the potential leak path being highlighted by the circle B. In the design of  FIGS. 4-11 , the weld is formed by rotating an exterior cylindrical surface  18 . 4  ( FIG. 5 ) against an interior cylindrical surface  16 . 6  ( FIG. 4 ) until the weld  20  has been formed by spin welding. The O-ring gland is formed by the shoulder  16 . 5 , the annular surface  18 . 3  and by an internal cylindrical surface  18 . 5 . Thus by having the internal cylindrical surface of the O-ring gland integral with the shoulder  18 . 3  the leak path identified at A in  FIG. 3  has been eliminated. 
     While the barb end portion  18 . 6  has been broken off in  FIGS. 1-7 , it is shown in  FIGS. 9-13 . To this end, it can be seen that the barb  18 . 6  may have differing configurations. Thus, as shown in  FIG. 9 , it has a single ferrule, while in  FIGS. 10-13  it has four barbs. Also, as shown in these FIGURES it may have differing orientations. 
     It is a feature of this invention that the female subassembly  14  and the male coupler are provided with mating interfitting parts to insure that the parts are in proper alignment with each other. To this end the male portion as illustrated is provided with a key  12 . 4  which may mate with a suitable keyway  16 . 6 . While a key has been shown on the male portion  12 , and a keyway on the female portion  16 , it should be obvious that other forms of interfitting parts may be utilized. The reason the parts are provided with interfitting parts are to insure that the parts are in the proper orientation with respect to each other. Thus, it may be desirable to have the right angle barb, as shown in  FIG. 12  90° offset from the keyway, whereas in  FIG. 13  it may be aligned with the keyway. 
     While forms of this invention has been described above and shown in the accompanying drawings, it should be understood that applicant does not intend to be limited to the particular details described above and illustrated in the accompanying drawings, but intends to be limited only to the scope of the invention as defined by the following claims. In this regard, the term “means for” as used in the claims is intended to include not only the designs illustrated in the drawings of this application and the equivalent designs discussed in the text, but it is also intended to cover other equivalents now known to those skilled in the art, or those equivalents which may become known to those skilled in the art in the future.