Multiple element cylindrical metallized film capacitors and method of making the same

In a multiple element, cylindrical capacitor wound from first and second dielectric films selectively metallized on one side and having at least one unmetallized section on one of said films selectively forming first and second layers of metal separated by dielectric film, the invention comprising:

• a metal insert having a metal tab extending therefrom,
• said metal insert interleaved between said first and second dielectric films in contact with said unmetallized section of one of said films,
• said metal tab extending from an end portion of said capacitor and adapted to receive an electrical connection thereto,
• an insulating insert interleaved between said first and second films between said metal insert on one of said metallized layers surrounding said metal insert to isolate said metal insert from said metallized layer whereby said metal insert forms a separate plate in said multiple element capacitor.

The method of making multiple element, cylindrical, metallized film capacitors from first and second dielectric films which are metallized on one side thereof, said metallized side of said first and second films only being exposed at opposite edges thereof, and which are wound in cylindrical form with the non-metallized side of one film being in contact with the metallized side of the other film and the metallized edges of said first and second films being exposed on opposite ends of said cylindrical capacitor comprising the steps of:

• removing a portion of the metallized side of said first film inward from the edge opposite the exposed metallized edge of said first film thereby forming a partial metallized region which extends over only part of the width of the metallized side of said first film,
• removing the metallized region across the width of said metallized side of said first film for a predetermined length of said first film following said partial metallized region thereby forming a totally demetallized region on said first film,
• winding said first and second films to form capacitor elements therebetween,
• inserting and winding an insulated strip between said first and second films located in said totally demetallized region of said first film, said insulated strip surrounding and forming a barrier around said partial metallized region of said first film,
• completing the windings of said first and second films,
• metal coating the end of said first film within said barrier containing said partial metallized region of said first film,
• connecting a leadwire to said metal coating within said barrier for making an electrical connection to a small capacitor element formed within said barrier.

The method of making multiple element, cylindrical, metallized film capacitors from first and second dielectric films which are metallized on one side thereof and which are wound in cylindrical form with the non-metallized side of one film being in contact with the metallized side of the other film comprising the steps of:

• providing a non-metallized area on a portion of the metallized side of said first dielectric film,
• inserting an insulating strip of predetermined length followed by a metal strip of predetermined length forming a single sheet between said first and second dielectric films, said metal strip overlaying said non-metallized area of said first film and forming one plate of a small capacitor of the multiple element capacitor being wound,
• isolating said one plate of the multiple element capacitor from the remaining elements thereof by winding at least one turn of said insulating strip around said metal strip,
• completing the winding of said first and second films, and
• connecting a leadwire to said metal strip which constitutes a connection to the small capacitor formed by said metal strip in said multiple element capacitor.