Abstract: In a probe point device for electrical tests the metallic point proper is carried by a hollow insulating handle or push member on which an insulating head is slidably mounted, spring and abutment means normally maintaining the head at a position of rest at which it wholly covers the point. A fuse cartridge is disposed within the push member to connect the point with the flexible cable provided at the rear of the said member. This cartridge has at its front end an axial indicator button which, when the cartridge blows, acts on a pivoted pawl to engage a first nose thereof into an inner circular groove provided in the head, thus locking the push member with respect to the head at the position of rest. A second tooth of the pivoted point member also locks the push member with respect to the head if the cartridge is missing.

Abstract: A pyrotechnical cartridge or motor (5) is actuated by electric firing from its head (5c), and pushes the insulating piston (3) which separates by shearing the intermediate connecting portion (1b) of the destructible conductor (1) and pushes it into the bore (1e) together with the rod (9), the conical end (9a) of which becomes wedged within the plug (10) so as to form a brake. The fuse cartridges (13) then open the circuit in a fully safe manner.The present invention is useful for instance under the control of overcurrent detectors.

Abstract: In a fuse cartridge the indicator button, normally retained within a head of the cartridge and adapted to protrude outwardly when the latter has "blown", is disposed axially to the said head and the contact blade corresponding to the latter has a notch formed in its inner transverse edge (the edge connected to the head) in order to define a space which may receive the indicator button. Moreover the lateral sides of the blade have laterally projecting ribs to limit the portion of said blade which may be inserted into the clamp of a cartridge support, thus preventing such a clamp from hindering the protruding movement of the indicator button.

Abstract: The brush holder comprises a cage and a detachable clip. The cage serves to accommodate a brush and has a channel. The clip has a central leg positioned in the channel. A self-winding band spring for biassing a brush is fixed at its outer end to the central leg, which also includes engaging means, e.g. in the form of a tongue, for retaining the central leg in the channel. The clip has also two side legs bearing elastically on to the outer sides of the cage to prevent rocking of the clip relative to the cage. The central leg has preferably raised side edges and the cage is preferably cut out from a hollow cross shaped section.