Duracell Inc.

Sean A Sargeant

Robert A Yoppolo

Marian Wiacek

William H Gardner

Christopher L DePalma

Peter J Pope

Stuart Michael Davis

William T McHugh

Douglas J Woodnorth

John Hession

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

An end cap seal assembly for an electrochemical cell such as an alkaline cell is disclosed. The end cap assembly comprises a convoluted end cap disk which may also function as a cell terminal and an underlying insulating disk also having a convoluted surface. The convoluted end cap disk has a downwardly extending wall with at least one aperture therethrough which preferably faces the ambient environment. The insulating disk has a downwardly extending wall forming a rupturable membrane which underlies and abuts the inside surface of the downwardly extending wall of the end cap. The rupturable membrane underlies and abuts the aperture in the downwardly extending wall of the end cap. When gas pressure within the cell exceeds a predetermined level the rupturable membrane pushes through said aperture and ruptures allowing gas to escape therefrom directly to the environment. A separate terminal plate may be welded to a portion of the top surface of the convoluted end cap. The conductive layer of a film-laminate condition tester may be connected to the terminal plate.

End cap seal assembly for an electrochemical cell

The invention is directed to a pressure activated current interrupt assembly for cells, particularly alkaline cells. The current interrupter is located at the closed end of the cell's housing. The current interrupter assembly comprises an electrically insulating member in proximity to the terminal at the closed end of the housing. The insulating member is in physical communication with a deflectable member formed from the cell's housing. When gas pressure within the cell builds up to exceed a predetermined value, the deflectable member deforms causing the insulating member to protrude beyond the extremity of said cell terminal, thereby preventing electrical contact between said terminal and the terminal of another cell or electrical device.

Pressure activated current interrupter for electrochemical cells

An end cap assembly is disclosed for sealing the open end of a cylindrical alkaline cell housing preferably having a diameter less than the diameter of AAA size cells. The end cap assembly is preferably intended for sealing AAAA (LR61) size cylindrical alkaline cells. The end cap assembly comprises a terminal end cap, an insulating sealing disk underlying said end cap, and an elongated current collector penetrating through an aperture in said insulating sealing disk. At least a portion of the insulating sealing disk lies within the cell housing to seal the open end thereof. The terminal end cap has a peripheral edge, preferably formed from a curved rib, which is locked within the peripheral edge of the insulating sealing disk. The end cap assembly does not require other metal disks held within the sealing and insulating disk. The insulating disk comprises a discontinuous skirt comprising a plurality of integral legs emanating downwardly into the cell interior from the peripheral edge of said insulating disk. The insulating sealing disk has an integrally formed rupturable membrane therein. The membrane ruptures when gas pressure within the cell exceeds a predetermined level.

An end cap assembly is disclosed for sealing the open end of a cylindrical alkaline cell housing preferably having a diameter less than the diameter of AAA size cells. The end cap assembly is preferably intended for sealing AAAA (LR61) size cylindrical alkaline cells. The end cap assembly comprises a terminal end cap, an insulating sealing disk underlying said end cap, and an elongated current collector penetrating through an aperture in said insulating sealing disk. At least a portion of the insulating sealing disk lies within the cell housing to seal the open end thereof. The terminal end cap is located outside of said housing. The end cap assembly may include an insulating washer between the terminal end cap and the cell housing. The terminal end cap and the insulating washer are stacked over the peripheral edge of the cell housing at the open end of the cell housing. The insulating washer electrically insulates the terminal end cap from the cell housing. The insulating sealing disk has an integrally formed rupturable membrane therein. The membrane ruptures when gas pressure within the cell exceeds a predetermined level.

End cap assembly for an alkaline 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

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.

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Westford, MA, United States of America

Sean A Sargeant