FUSED CATHODE ELECTROLYTIC CAPACITORS AND METHOD OF MAKING THE SAME

• US 3,789,502 A
• Filed: 06/05/1972
• Issued: 02/05/1974
• Est. Priority Date: 06/05/1972
• Status: Expired due to Term

• Current Assignee: Harold T. Callins, William H. Doster
• Original Assignee: Harold T. Callins, William H. Doster
• Inventors: Callins, Harold T., Doster, William H.
• Primary Examiner(s): Tupman, W. C.
• Application Number:
  US05/259,920
• Time in Patent Office: 610 Days
• Field of Search: 29/570,25.42
• US Class Current: 29/25.03
• CPC Class Codes: H01G 9/008 Terminals

Abstract

A metallic foil electrolytic capacitor and method of making the same, wherein anode and cathode foils and dielectric sheets are wound into a capacitor cartridge or roll with a lateral edge of the cathode foil protruding in exposed relation at the bottom of the roll beyond the edges of the dielectric sheets and anode foil insulated therebetween, and thermally fusing the protruding exposed cathode foil edges together in a selected pattern spanning the bottom of the roll.

Claims

1. A method of making an electrolytic capacitor of the type having a spirally wound capacitor cartridge forming a roll of sandwiched dielectric sheets and anode and cathode foils, the method comprising the steps of superposing elongated strips of anode foil and cathode foil and plural dielectric sheets in a stacked arrangement wherein one dielectric sheet is interposed between the foils, the anode foil being narrower transversely than the sheets and having its lateral edges located inwardly of both sheet edges and the cathode foil having one lateral edge protruding outwardly beyond the adjacent sheet edges, winding the stacked arrangement of foils and sheets into a spirally wound roll of plural convoluted turns wherein the protruding edge of the cathode foil in each convoluted turn extend in outwardly exposed relation from the adjacent sheet edges at the bottom of the roll, and thermally fusing the protruding edges of the respective convoluted turns of the cathode foil to each other along a fused pattern traversing the bottom of the roll to provide a fused metallic connection between the cathode foil portions of the spirally wound turns, said fused pattern including a first group of strokes spanning the roll and substantially paralleling a diameter of the roll and a second group of strokes spanning the roll and arranged substantially perpendicular to said first group collectively forming a crosshatch pattern of strokes.

2. The method of making an electrolytic capacitor as defined in claim 1, wherein said thermal fusing step is performed by stroking said protruding cathode foil edges with a tool while applying appropriate electrical potentials to the cathode foil and tool to effect localized heating at the contact points therebetween producing thermal fusing of adjacent cathode foil exposed edges of adjacent convoluted turns to each other.

3. The method of making an electrolytic capacitor as defined in claim 1, wherein said thermal fusing step is performed by connecting the cathode foil and an electrode having a pointed working end to opposite polarity terminals of a voltage source of sufficient magnitude to produce localized melting of the cathode foil material upon contact with said pointed working end, and drawing the pointed working end of the electrode across the exposed cathode foil edges along said pattern to thermally fuse said cathode edges together.

4. The method of making an electrolytic capacitor of the type having a spirally wound capacitor cartridge forming a roll of sandwiched dielectric sheets and anode and cathode foils, the method comprising the steps of superposing elongated strips of anode foil and cathode foil and plural dielectric sheets in a stacked arrangement wherein one dielectric sheet is interposed between the foils, the anode foil being narrower transversely than the sheets and having its lateral edges located inwardly of both sheet edges and the cathode foil having one lateral edge protruding outwardly beyond the adjacent sheet edges, winding the stacked arrangement of foils and sheets into a spirally wound roll of plural convoluted turns wherein the protruding edge of the cathode foil in each convoluted turn extend in outwardly exposed relation from the adjacent sheet edges at the bottom of the roll, and thermally fusing the protruding edges of the respective convoluted turns of the cathode foil to each other along a fused pattern traversing the bottom of the roll to provide a fused metallic connection between the cathode foil portions of the spirally wound turns, said thermal fusing step being performed by connecting the cathode foil and an electrode having a pointed working end to opposite polarity terminals of a voltage source of sufficient magnitude to produce localized melting of the cathode foil matErial upon contact with said pointed working end, and drawing the pointed working end of the electrode across the exposed cathode foil edges along said pattern to thermally fuse said cathode edges together.