Duracell Inc.

Robert A Yoppolo

Marian Wiacek

Sean A Sargeant

Peter J Pope

Christopher L DePalma

Robert J Payne

William T McHugh

Douglas J Woodnorth

Vance R Shepard, Jr

Francis Bruce Tubby

Peter Rick Moses

Lucian P Fontaine

Boris Falczuk

An end cap assembly for an electrochemical cell, for example an alkaline cell, is disclosed comprising an exposed terminal end cap of single piece construction having a convoluted surface, an electrically insulating member and a metal support disk between the insulating member and the terminal end cap. The end cap assembly is inserted into the open end of the cell housing after the cell contents have been supplied. A portion of the end cap surface is a flat annular step which improves contact between the end cap and the electrically conductive portion of a condition tester for the cell which may be integrated into the cell label. The annular step is advantageously located at about right angle to the cell's longitudinal axis. The surface step is integral with the end cap and preferably located at about the same level as the shoulder of the cell housing at the end of the cell containing the end cap. The end cap assembly as a whole provides a tight seal for the cell.

End cap assembly for an electrochemical cell

End cap assembly for electrochemical cell

A metal support disk useful in sealing an electrochemical cell exerts a resilient outward radial force against the seal to assure seal integrity over a wide temperature range and exerts an upward force against an adjacent metal end cap terminal to assure continued mechanical and electrical contact with the terminal. The support is a stepped disk having a centrally located, shallow, cylindrical pill-box, with the bottom of the pill-box extending radially outward into an annular ring. A spring means in the form of an S-shaped rim extends down from the periphery of the ring, terminating at its bottom in an outward extending flange. The edge of the flange presses a plastic seal member against the inside wall of the cell to form the seal.

Upward deflecting support disk for electrochemical cell seal

An electrochemical cell has a wheel shaped, molded plastic seal member of a unitary construction which includes a central cylindrical hub from which depend in outward radial sequence, an annular pressure vent, a boss, a downward projecting skirt, an annular flexure means for providing radial movement and an outer rim terminating at its periphery in a cylindrical wall. The pressure vent includes a thin membrane ring depending from the hub which joins the hub to an annular diaphragm. A hinge ring joins the periphery of the diaphragm to the boss. The seal member is designed so that the membrane ring fails primarily in shear at excessive cell pressure which makes the vent more reliable and easier to fabricate.

Seal for electrochemical cell

A metal support disk for an electrochemical cell seal exerts a resilient outward radial force against the seal to maintain seal integrity over a wide range of operating temperature and, at the same time, exerts an upward force against the bottom of the metal end cap terminal of the cell to assure electrical contact between the anode inside the cell and the terminal. The disk includes a central, circular platform connected to an outer, sealing edge sealing flange by an annular flexure means which permits radially inward and outward movement of the sealing edge when the end of the cell is radially crimped during the sealing process. The crimping also moves the central portion of the disk up which results in the upward force being exerted against the end terminal. The flexure means is a sequential series of three annular, curved fibs with the first and third curved downward and the second curved upward. A ring depending radially outward and at an upward angie from the first fib connects the first fib to the second fib and helps to prevent plastic deformation of the disk during sealing.

An electrochemical cell having an on-cell tester for visually indicating the condition of the cell is provided with an electrically conductive metal ring pressed onto the negative terminal at the crimp seal end of the cell, to permit the tester lead to make an electrical contact with the negative terminal without shorting across the positive terminal of the cell. The ring has a cylindrical wall portion or gripping means which frictionally grips a corresponding mating cylindrical wall potion on the negative terminal and also has a flange portion adjacent the positive terminal. A layer of electrically insulating material disposed between the flange and positive terminal prevents electrical contact between the terminals. The tester lead is either permanently electrically connected to the ring or intermittently connected by the user, depending on the type of tester used.

Contact ring for on-cell battery tester

An improved method for sealing an electrochemical cell comprises applying radial forces to an expanded, upper portion of the cell casing. A resilient sealing member is located in the upper portion so that when the radial forces reduce the diameter of the expanded casing portion the sealing member is compressingly held in place.

Crimping method for electrochemical cells

This invention relates to a seal for a cylindrical alkaline cell. The member includes a metal support having an annular spring disposed at the outer periphery. The spring is placed under compression by a radial crimp and the spring is adapted to expand and contract whereby the seal is maintained during thermal cycling. The member also includes a plastic grommet having an annular vent designed to open at very high pressures whereby said seal member is particularly useful in alkaline cells having little or no mercury whereby high internal pressures can develop.

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Woonsocket, RI, United States of America

Robert A Yoppolo