Method and apparatus of assembling a fluid flow conduit assembly of dissimilar plastics

#1. Field of the Invention

#The present invention relates to fluid flow conduit assemblies and methods of assembling same, and more particularly to conduit assemblies in which the tubing plastic is dissimilar from the plastic member to which it is to be attached, such as a joint, reservoir or manifold.

#2. Description of the Prior Art

#These and other objects of the present invention will become evident particularly when taken in light of the following illustrations wherein:

#FIG. 1 is a cross-sectional view of the end of a conduit constructed of one type of plastic material, and a manifold or coupling element of a dissimilar plastic material to which the conduit must be mechanically secured and sealed; and

#FIG. 2 is a cross-sectional view of FIG. 1 illustrating the conduit and coupling element undergoing mechanical connection and sealing; and

#Referring to FIGS. 1, 2 and 3 there is illustrated a cross-sectional view of an end of a conduit of plastic tubing 3 constructed or fabricated from cross linked polyethylene which must be mechanically secured and sealed with respect to a coupling element 4 of dissimilar plastic secured to a manifold reservoir or the like. FIGS. 1, 2 and 3 are illustrative of the steps to achieve the secure connection. This mechanical connection and hermetic sealing is accomplished by positioning a compression ring 1 slidably received about the tubing 3, and thereafter positioning a thermoplastic bonding material 2 in the form of a slidably receivable gasket about the end 6 of tubing 3. The thermoplastic bonding material 2 is that which is described in U.S. Pat. No. 3,620,875, which is incorporated by reference.

#Once the compression ring 1 and the thermoplastic bonding gasket 2 are in position proximate the end 6 of tubing 3, tubing 3 and the thermoplastic bonding gasket 2 are inserted into the receiving receptacle 9 of coupling element 4. The heating of the thermoplastic bonding gasket 2 and the tubing 3 is accomplished by means of a work coil 5 positioned about the part or manifold 4. Thermoplastic bonding gasket 2 heats up as a result of the RF introduced by coil 5 and softens the end 6 of tubing 3. Pressure is brought to bear on tubing 3 and the softened tube end 6 of tubing 3 is forced to flare outwardly to conform to the shape of the fillet 10 in the receiving receptacle 9 (See FIG. 2). At this point pressure is applied to the compression ring 1 to engage receiving receptacle 9 which compresses the molten thermoplastic bonding gasket 2 into the void 12 between the coupling element 4, the flared ends of tubing 3, and the end 14 of the compression ring 1. The thermoplastic bonding gasket 2 sets upon cooling forming a mechanical connection between the coupling element 4, the compression ring 1 and the tubing 3 (See FIG. 3). Not only is the mechanical seal accomplished, but also the hermetic seal with respect to any fluids passing between the part and the tubing or vice versa.

#The amount of electromagnetic energy absorbing material is at least 60 percent to about 76 percent by weight of the gasket member and is of a material selected from the group consisting of iron, cobalt, nickel, alloys containing nickel, alloys containing cobalt, and alloys containing iron.