Drawout switchgear apparatus with retractable shutter mechanism for terminal stabs

Claim 1

Switchgear apparatus comprising: a cell; a plurality of spaced fixed terminal stabs in the cell; a switchgear unit removably disposed in the cell and including terminal means for detachably engaging the terminal stabs during movement into and out of the cell; a barrier of electrically insulative material including a first shutter having opening means for receiving the stabs; support means including links movably mounting the shutter between lateral positions of nonalignment and alignment of the opening means with the stabs and biased in the nonalignment position; obstruction means retractably mounted in the path of movement of the shutter for barring movement of the shutter from the nonalignment position; the unit including trigger means releasing the obstruction means when the unit moves into the cell so as to retract the obstruction means from the path of movement of the shutter to enable the opening means to align with the stabs and to enable connection of the terminal means with corresponding stabs; a second shutter adjacent to the first shutter and having holes aligned with the stabs, the second shutter being biased away from the stabs and is disposed on the side of the first shutter away from the stabs; and the links including roller means extending through the opening means for rolling contact with the second shutter so that as the unit moves into the cell the unit retracts the second shutter and causes the first shutter to retract laterally and to thereby bring the opening means into alignment with the stabs whereby the stabs are exposed to the terminal means.