The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 03, 2000
Filed:
Aug. 27, 1998
William H Gardner, North Easton, MA (US);
Duracell Inc., Bethel, CT (US);
Abstract
The invention is directed to a method of forming a pip protrusion at the closed end of a cylindrical casing of an electrochemical cell. The cell is preferably an alkaline cell having an anode comprising zinc, a cathode comprising manganese dioxide, and an alkaline electrolyte. The method of the invention is directed to forming the pip protrusion at the closed end of the casing so that the pip protrusion becomes an integral part of the casing. In an alkaline cell the pip protrusion becomes the cell's positive terminal. The method of the invention involves inserting cathode material into the casing through the open end thereof and then forcing an elongated plunger having a diameter less than the inside diameter of casing into the cathode material while providing means for preventing the cathode material form rising more than a predetermined level with the casing. The force of the plunger causes the cathode material to become compacted while simultaneously causing a pip protrusion to form at the closed end of the casing.