In the electrical distribution field, a great number of electrical or electronic devices are mounted within a switchgear cabinet, the electrical or electronic devices including for example miniature circuit breakers, residual current circuit breakers, lamps, bell transformers, timer and push buttons etc. Each of such devices includes a mounting face which is so shaped as to match with an elongated bearing rail, for example, a so-called DIN rail which has a Ω-shaped cross-section. The DIN rail is fixed by screw or nuts to a supporting portion of a cabinet frame of a switchgear. The DIN rail has oppositely-disposed side walls provided, at both free edges thereof, with outwardly extending flanges. On the mounting face of each electrical or electronic device there is obtained a U-shaped recess having, on one boundary edge thereof, an inwardly turned lip and, on the opposite boundary edge, an inwardly protruding catch urged by a spring towards the inwardly turned lip. When a device has to be mounted on the DIN rail, the inwardly turned lip is put to engage behind one outwardly extending flange, and the spring-loaded catch makes a snap fit behind the other outwardly extending flange of the DIN rail. Subsequently, the electrical terminals of such a device have to be joined one by one directly to an elongated busbar extending alongside the DIN rail. These mounting and connecting operations are rather wearisome and time-consuming because have to be repeated several times, i.e. have to performed for each of the above mentioned electrical/electronic devices. Furthermore, if it occurs that all these devices have to be moved to a new location within the cabinet, each of them has first to be electrically disconnected and then mechanically decoupled from the DIN rail. Subsequently, the screws or nuts, which previously might be covered by the electrical devices, must be unscrewed thus enabling the DIN rail to be removed and be fixed to the new desired location within the cabinet. The electrical devices can thus be remounted on the DIN rail in the new location.
It would be desirable to overcome all the above mentioned drawbacks, by providing a clamping element which is simple and cheap to manufacture, and which enables a plurality of electrical/electronic devices to be quickly and easily connected within a switchgear cabinet in a versatile way.