Ignition cable terminal construction

Abstract

A method and means for improving the connection between a resistive core ignition wire and a terminal is disclosed. The improvement comprises placing a conductive metallic band around the outer insulation of the wire after exposing the core, and folding the core back over the conductive metallic band before crimping the terminal in place. The invention is best suited for use with ignition wire of the type having a conductive elastomeric or polymeric coating around the central core, and eliminates possible loss of electrical contact between the core and the terminal which may occur due to plastic deformation of the wire at elevated temperatures.

I claim: 
     
       1. A method of attaching a terminal to an ignition cable for use with internal combustion engines, said cable having a central .[.resistive.]. conductive core, an inner insulation layer concentric with said core and an outermost insulating layer concentric with and surrounding said inner insulation layer, comprising the steps of; removing a portion of said inner insulation layer and of said outermost insulating layer from said conductive core for a predetermined distance from an end of said cable to form an exposed core end portion;   placing a narrow strip of conductive sheet material in contact with at least a portion of the circumference of said outermost insulating layer adjacent said core end portion;   bending said core end portion back over said sheet material; and   clamping a terminal ferrule over said core end portion, said sheet material and said outermost insulation layer to make direct electrical contact between said core end portion and said ferrule.   
     
     
       2. A method according to claim 1, wherein: said step of placing said sheet material in contact with said outermost insulating layer includes the step of wrapping a strip of metal foil around said outermost layer of said cable.   
     
     
       3. A method according to the claim 1, wherein: said step of placing said sheet material in contact with said outermost insulating layer includes the step of placing a C-shaped metal strip around said outermost layer of said cable.   
     
     
       4. A method according to claim 1, wherein: said step of placing said sheet material in contact with said outermost insulating layer includes the step of bending a metal strip around the periphery of said outermost layer of said cable to form a band around said cable.   
     
     
       5. An ignition cable assembly having an outermost insulating layer, an inner insulating layer concentric with said outermost layer and a central .[.resistive.]. conductive core and a terminal ferrule fastened to said cable at an end thereof, characterized in that a predetermined length of said conductive .[.resistive.]. core is exposed at said end of said cable, a portion of said exposed core is bent back over said outermost insulating layer, a narrow strip of conductive sheet material is interposed between said bent back portion of said exposed core and said outermost insulating layer, said sheet material.[.,.]. and said bent back portion of said exposed core.Iadd., .Iaddend.to .[.form.]. .Iadd.make .Iaddend.a permanent electrical connection between said core and said ferrule, said sheet material being adapted to prevent plastic deformation of said cable due to elevated ambient temperature from affecting said electrical connection. 
     
     
       6. An ignition cable according to claim 5, wherein said sheet material is a narrow strip of conductive metallic foil wrapped around said outermost insulating layer. 
     
     
       7. An ignition cable according to claim 5, wherein said sheet material is a narrow conductive metal strip substantially concentric with at least one half of the periphery of said outermost .[.conducting.]. .Iadd.insulating .Iaddend.layer. .Iadd. 8. A method of attaching a terminal to a cable, said cable having a central conductive core, and an outermost insulating layer concentric with and surrounding said central conductive core, comprising the steps of: forming an exposed core end portion by removing said outermost layer from said central conductive core for a predetermined distance from an end of said cable; then   placing a narrow strip of conductive sheet material in a circumferential direction with respect to said cable and in contact with substantially more than half of the circumference of said outermost insulating layer adjacent said core end portion; then   bending said core end portion back over said sheet material; and then   clamping a terminal ferrule over said core end portion, said sheet material and said outermost insulation layer to make direct electrical contact between said core end portion and said ferrule. .Iaddend..Iadd. 9. A cable assembly having an outermost insulating layer and a central conductive core and a terminal ferrule fastened to said cable at an end thereof, characterized in that a predetermined length of said conductive core is exposed at said end of said cable, a portion of said exposed core is bent back over said outermost insulating layer, and a narrow strip of sheet material is disposed in a circumferential direction with respect to said cable and in contact with substantially more than half of the circumference of said outermost insulating layer and interposed between said bent back portion of said exposed core to form a permanent electrical connection between said core and said ferrule. .Iaddend.