Patent ID: 8517042

Claim:
A rupture disk for relieving pressure between the interior of a battery box and the exterior of the battery box, the box having an outlet opening, comprising: a) a first layer that provides a gasket which abuts the battery box, the gasket having a central opening which aligns with the battery box opening; b) a second layer in the form of a reverse buckling disk having a disk flange with first and second flange sides, the first flange side engaging the first layer, a domed portion and a weakened score on the dome that defines a disk burst pressure, the second layer having concave and convex sides; c) a third layer that is an outlet ring, the outlet ring being on the concave side of the second layer and in contact with said flange second side and having a central opening surrounded by an edge wherein the convex side of the second layer extends into the first layer central opening; d) a plurality of teeth on the third layer extending from said edge inwardly a distance, each tooth having a circumferentially extending edge, said edge aligning with and extending along a portion of the score; e) a plurality of spaced part recesses, each recess being between two of said teeth; f) a plurality of tabs on the first and third layers, said tabs including circumferentially spaced apart tabs on each of said first and third layers, each tab having a tab opening, said tabs generally aligning so that a fastener can be passed through a tab opening of the first layer and a tab opening of the third layer; g) fasteners that affix the first and third layers to the box; h) wherein the second layer is generally circular and surrounded by the fasteners; and i) wherein the circumferentially extending edge of each tooth is positioned on the concave side of the second layer and next to the score.