Guide rail set for electrical components of electrical devices guided in guide rails

In a guide rail set for receiving an electrical component of an electrical device, each set being composed of two individual guide rails, each guide rail, at the respective ends of the rails, having means for fastening the rail to a frame part of an electrical device so that when the rails are mounted in the device, a back surface of each of the rails is against a seating surface of the frame part and a front surface of each rail has allocated guide channels which lie opposite one another for receiving the component part, the improvements comprising the seating surface of the frame part having a T-shaped aperture for each fastening means, each T-shaped aperture having a transverse portion and a longitudinal portion, each fastening means including a sub-group being provided on a back surface of each of the guide rails for introduction into the transverse portion of the T-shaped aperture in the frame part of the electrical device and with axial longitudinal displacement of the guide rail, the sub-group is shifted into the longitudinal portion of the aperture for embracing longitudinal edges of the longitudinal portion of the T-shaped aperture of the frame part, said sub-group of each of the fastening means of one guide rail of the set being arranged offset to the sub-group of the fastening means of the other guide rail of said set so that when the guide rails of the set are placed with the back surfaces against one another, the fastening means are positioned offset next to one another, and at least one sub-group of each guide rail including a spring tongue that projects from a position adjacent a front edge of each rail toward a back end of the rail in a direction opposite to the axial displacement of the guide rail during mounting and having a free end that projects beyond a back surface of the respective guide rail for engaging an edge of one of the T-shaped apertures.