David S Shapiro

US Patent:

58539123, Dec 29, 1998

Filed:

Jul 10, 1996

Appl. No.:

8/677961

Inventors:

Htun S. Naing - Cockeysville MD
David Shapiro - Valdese NC

Assignee:

SAFT America, Inc. - Valdosta CA

International Classification:

H01M 200

US Classification:

429 61

Abstract:

An explosion-proof valve electrical disconnect assembly incorporates a vent valve contact disk which seals the can of a compact electrochemical cell and which faces a juxtaposed stripper contact disk welded at the center by a weld nugget at a weld point, forming a rigid, preferably increased thickness, mass. The underlying stripper contact disk is weakened about the weld point, surrounding the weld nugget to ensure pull-through of the stripper contact disk portion immediately adjacent to the weld connection to effect initial electrical separation of the two contact disks. Subsequent rupture of the vent valve contact disk releases high pressure gas internally from the cell. A semi-rigid assembly cup may support a rigid grommet functioning to sandwich the vent valve contact disk and the stripper contact disk facilitated by crimping of the can top about a deformable L-shaped cross-section annular assembly cup. A current responsive PTC element forms a second circuit breaker independent of the first mechanical circuit breaker formed by the two contact disks.