An electrical device includes an actuator assembly configured to facilitate selective opening/closing of an electrical circuit. A plunger is positioned to be acted on by a magnetic field, a shaft is coupled to the plunger, and a movable contact is coupled to the shaft. The plunger includes an axial opening and an undercut formed in a surface defining the axial opening. The shaft is inserted into the opening and an end of the shaft extending from the opening is altered to increase a diameter of the shaft to prevent passage through the opening and such that a portion of the shaft extends into the undercut.

A rail attachment for supporting a support rail includes two rail brackets engaging with and securing the support rail therebetween, a connector securing the two rail brackets to one another and including an attachment unit suspending the rail brackets and support rail, each the rail bracket including a support section engaging and secured to the support rail and each bracket further including a first connection section extending over the support rail, an intermediate region and a distal region whereby the distal region is spaced from the support section by the intermediate section and wherein the distal region is of a greater length than the intermediate region as considered in a direction perpendicular to the direction in which the intermediate region spaces the distal region from the support section, and the connector including a second connection section securing the distal regions of the rail engagement brackets relative to one another.

A tool presses a joining element against a first object into a first opening of the first object while mechanical vibration energy is coupled into the first object and the joining element. Vibration energy and pressing force make the thermoplastic material of the distal portion of the joining element flowable and interpenetrates structures of the first object to yield, after re-solidification, an anchoring of the distal portion of the joining element in the first object. The second object is placed so that a proximal portion of the joining element is inserted into a second opening, and the first and second objects are pressed against each other while mechanical vibration energy is coupled into one of the first and second objects, until thermoplastic material of the joining element proximal portion is made flowable and interpenetrates structures of the second object to yield, after re-solidification, an anchoring in the second object.