Transmission shaft for an installation switchgear

The invention relates to a transmission shaft for an installation switchgear comprising at least one contact point, a hammer armature system for opening the contact point in the event of a short-circuit and a switching lock with a release lever, wherein the hammer armature acts upon the switching lock in order to unlatch it, thereby opening permanently the contact point. The transmission shaft can be mounted into the installation switchgear so as to be pivotable between an idle position and a tripping position for ensuring the mechanical coupling of the hammer armature with the release lever and a short-circuit signaling unit and for ensuring the mechanical coupling of an auxiliary release with the release lever. The transmission shaft comprises a first, internally positioned partial shaft that is rotatably mounted in a second, externally positioned partial shaft in such a manner that the first partial shaft, independently from the second partial shaft, is pivotable between the idle position and the release p