Patent Application
20070222214
The subject invention relates to fluid connectors and, more particularly, to the sealing interconnection of such connectors with tubing endforms and, more particularly still, the use of spin welding to effect such interconnection.
Generally rigid pipes, such as hard copper pipes, are commonly used in the plumbing industry. However, the use of pliable hose or tube material provides for optimal flexibility when routing water pipes in homes or buildings. But the use of traditional compression collars for connecting more flexible conduit creates a difficulty in attaining connection points. One cost effective design is the plastic housing female type quick connector releasably mated to a male tube endform. The opposite end of the female connector body most typically defines a stem having a member of axially spaced barbs formed on the outer circumferential surface thereof and a nylon or plastic tubing endform pressed there over. Such an arrangement is described in U.S. Pat. No. 5,542,712.
In fluid handling systems, it is imperative that the connectors used have first and second fluid carrying components portions properly coupled together. A faulty connector enables an associated system to leak fluid. This can be particularly disadvantageous when the system is under pressure and the leaking connector expels the pressurized fluid.
A related problem stems from dual aspects of commercially available quick connect devices, to with: high volume and low sale price frequently necessitating the use of inexpensive, somewhat pliable materials, and complex contours of extremely small inter-fitting components. These aspects collectively increase the likelihood of misassembly. High volume production techniques, including automated assembly tends to aggravate the problem wherein misassembly or impermissible dimensional variations of the components are difficult to detect. Excessive dimensional tolerance stack-up can result in low pull-apart characteristics between the barbed stem and the plastic tube and produce leakage. Misassembly, such as failure to include an O-ring, can also result in leakage. In the case of multi-layer tubes, dimensional and/or adhesive problems can result in mechanical delamination upon insertion of the tube over the barbed stem. Finally, mono-wall plastic tube or multi-layer structures with low hoop strength can relax over time or at elevated temperatures, resulting in leaking or weeping of fluid.
The present invention provides a simple and inexpensive watertight connection between a tube end and a connector body.
In one aspect, the present invention is a fluid coupling formed of spin weld joined first and second fluid carrying components. The first fluid carrying component can be formed of a tubular member having a through bore extending from a leading edge. The second fluid carrying component can be formed of a connector body having a fluid passage extending from a first opening to a second opening and an endform with an outer weld surface configured to be inserted into the bore of the first fluid carrying component. The first fluid carrying component is permanently affixed to the second fluid carrying component by spin welding. A spin weld inducing bonding material layer can be disposed on the outer weld surface of the connector body to spin weld join the first component to the second component.
In another aspect, the present invention is a method of fluid coupling first and second fluid carrying components. The method comprises the steps of positioning a first fluid carrying component, such as a tubular member, having a through bore extending from a leading edge, to receive a second fluid carrying component, such as a connector body, having a fluid passage extending from a first opening to a second opening and an endform with an outer weld surface; aligning the bore of the tubular member concentrically with the fluid passage of the connector body; inserting the endform of the connector body into the bore of the tubular member; and spin welding the first and second fluid carrying components causing the material to sealingly join the tubular member and the connector body.
The outer weld surface can be terminated by a radially extending flange having an end wall positioned a distance from an edge of the connector body. A collar having a diameter substantially equal to the diameter of the tubular member can be located adjacent to the end wall of the flange. The endform of the connector body can be inserted into the bore of the tubular member until the leading edge contacts the collar.
Alternatively, the endwall of the flange can include an annular recess configured to receive the leading edge of the tubular member. The method can include the step of engaging the leading edge of the tubular member into the annular recess.
The spin weld fluid coupling and method of making the same of the present invention provides a spin weld coupling between two fluid carrying components which uniquely enables the use of materials forming the first and second components to be spin welded together in a permanent, secure, leak-free joint.
The various features, advantages, and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which:
Referring to
It will be understood that the fluid coupling uses the illustrated tubular member 20 by way of example only. Alternately, the fluidic coupling of the present invention may be embodied in a configuration applied to other standard plumbing elements.
As illustrated in
An annular flange 28, located intermediately between the first 15 and second ends 17, extends radially outward from the outer surface 26 of the connector body 12. An endform 32 and an outer peripheral surface 34 of the endform 32 are defined between the second end 17 and the annular flange 28. The outer surface 34 of the endform 32 defines an outer weld surface of the connector body 12. The endform 32 of the connector body 12 can be adapted to be inserted into the bore 22 through a first opening of the tubular member 20 as shown in
Alternatively, as shown in
At least one and, optionally, all three of the radially inner recess surface 50, the radially outer recess surface 52 and the inner end wall 54 can be covered with a bonding material layer 56 which is spin weld compatible with both of the materials on the outer surface 34 of the endform 32 and tubular member 20. For example, SANOPRENE may be employed as a spin weld inducing bonding material.
The bonding material is applied to the recess surfaces 50, 52, 54 by suitable means, which may include double shot injection molding during injection molding of the connector body 12. The double shot injection molding process insures that all of the surfaces are covered with the bonding material.
Alternately, the bonding material may be inserted into the recess 46 by other techniques. In one aspect, the bonding material may be fixtured in a loose form on any or all the surfaces. During the spin welding of the tubular member 20 relative to the connector body 12, the loose bonding material melts and then solidifies to fuse the elements together.
The bonding material is applied to the surfaces in a thickness to form an opening between opposed surfaces of the bonding material in the recess 46 which is capable of easily receiving the sidewall thickness of the leading edge 38.
The tubular member 20 can be formed of a plastic tube or conduit having an inner surface. For example, one multi-layered tubular member 20 may include a fluoropoylmer inner-layer, a NYLON outer-layer and an intermediate layer 58 of adhesive such as an Admer adhesive to bond the two layers together. The same adhesive may be used as a compatibilizer or as a spinweld inducing material applied to the inner services of the recess.
Alternately, the compatibilizer or spinweld inducing bonding material may be a NYLON 6/12 disposed on the surfaces in the recess between a NYLON 12 fluid connector endform and a NYLON 6 tube member. The connector endform can alternately be formed of NYLON 6 and the tube member formed of NYLON 12, with the same NYLON 6/12 compatibilizer.
Referring to
The connector body endform 32 may be mounted rigidly and the tubular member 20 mounted for relative rotation therewith in a suitable press, for example. As shown in
The various control parameters in spin welding are generally well known, albeit in other applications. For the sake of brevity such parameters will not be repeated here, reference being made to U.S. Pat. Nos. 2,933,428; 3,980,248 and 5,152,855.
During the spin welding process, the inner weld surface 44 of the tubular member bore 22 frictionally engages the radially outer weld surface 34 of the connector body endform 32 to melt the surfaces thereof to a weldment zone 60. As shown in
In conclusion, there has been disclosed a unique fluid coupling which uses a bonding material which is spin weld compatible with the materials outer surface 34 of the endform 32 and the tubular member 22 to ensure a sealed, leak free connection between the endform 32 and the tubular member 20. The unique quick connector and fluid coupling according to the present invention enable a flexible plastic tube 20 to be sealingly joined to a plastic connector body 12 via a spin welding process which ensures a complete 360° seal between the connector body 12 and the tubular member 20.
