Patent ID: 7034642
Filing Date: 2006-04-25
Classification: H01H

Abstract:
1. A moving contact assembly for electrical switching apparatus comprising: a carrier body; carrier legs supporting the carrier body for pivotal movement between a closed position and an open position; an outer carrier secured to the carrier body; an inner carrier having inner carrier sidewalls mounted on the outer carrier for pivotal movement between a withstand position and a blow open position and having an end wall with a cam profile, the end wall extending between the inner carrier sidewalls, and a cross wall having contact spring pockets and also extending between the inner carrier sidewalls; a plurality of contact fingers pivotally mounted on the inner carrier; contact springs seated in the contact spring pockets and bearing against the plurality of contact fingers; a cam follower pin; cam springs seated against the outer carrier biasing the cam follower pin against the cam profile which is configured so that for current through the contact fingers less than a threshold current, the inner carrier is biased to the withstand position and for current through the plurality of contact fingers greater than the threshold current, the inner carrier is rapidly driven to the blow open position; and a gas shield associated with the carrier body and having a concave inner surface facing the cross wall of the inner carrier, the cross wall having a convex outer surface complementary to and in close proximity to the concave inner surface on the gas shield to maintain a gas seal as the inner carrier pivots from the withstand position to the blow open position.