Apparatus for bonding a plastic case to a stub cable

#This invention relates to a method and apparatus for bonding a plastic case to a plastic sheathed stub cable, and more particularly to orbiting a coiled section of cable about a straight section of the cable while bonding an apertured casing cap to the end of a plastic sheath jacketing the cable.

#Loading coils find wide-spread use in the telephone industry wherein the coils are connected in series with individual telephone wires to balance detrimental effects of capacitance between wire pairs and, thus, improve signal transmission characteristics. The failure to balance the capacitance effect results in attenuation and distortion of telephone conversations. Traditionally, arrays of loading coils have been packaged in steel or other metallic casings. In copending application Ser. No. 864,304, filed Dec. 27, 1977, now U.S. Pat. No. 4,172,965, in the names of J. D. Eyestone and M. E. Szymanski, there is shown a packaged loading coil assembly that is encased in a plastic housing. Plastic housings of this type are made up of a number of component sections which must be bonded together and bonded to a stub cable containing wire pairs that are connected to the telephone communication wires.

#The present invention is particularly concerned with facilities for bonding a plastic component of a loading coil housing to the plastic sheath that jackets a stub cable that also has a coiled section. It is known that plastic parts of various types of housings may be bonded together by extruding a bonding plastic bead along a juncture of the parts. In other situations, thermoplastic parts of a container have been joined by heating and applying pressure to a juncture between the parts. In U.S. Pat. No. 2,319,683 there is shown an apparatus for joining two sections of a bottle-like thermoplastic container. More particularly, the patent discloses apparatus for rotating the parts of the container while applying heat and pressure to a juncture between the parts so as to soften and fuse a bead on one part to the other part.

#Other features and advantages of the present invention will be apparent upon consideration of the detailed specification and the drawing, wherein

#FIG. 1 is a side elevational view, partially in section, of an apparatus for welding a plastic sheath on a stub cable to a plastic part of a casing, utilizing the principles of the present invention;

#FIG. 2 is a top view taken along line 2--2 of FIG. 1 showing the construction of a device for shaping a weldment joining the stub cable to the casing part;

#As best seen in FIGS. 1, 3 and 4, there is shown a stub cable 10 made up of bundles of insulated wires 11 that are utilized to interconnect arrays of individual loading coils with telephone transmission wire paths. The individual loading coils may be stacked and mounted in a plastic casing or housing of the type shown in the afore-identified copending application of Eyestone and Szymanski. A part of this casing may be formed of low density polyethylene in the shape of an apertured necked part or cap 12 that is bonded to a straight section 13 of the stub cable 10.

#A cable 10 of this type may be constructed of bundled groups of pairs of polyethylene insulated wires which are wrapped and held in place by overlaying spirals of paper. The paper-wrapped bundles of wire may be overlayed with tubular shields of aluminum and steel, and finally the shields are jacketed with a low density polyethylene sheath.

#In preparation for the attachment of the wires to the loading coils and the assembly of the loading coils in a plastic housing, a section 14 of the cable is stripped of the metal shields and the polyethylene sheath, and a major section of the cable is wound into a coiled section 16 to facilitate handling during various assembly operations. The method and apparatus of the present invention is concerned with bonding or welding the apertured casing cap 12 to the end of the polyethylene sheath on the straight section 13 of the cable.