Abstract: A ring binder mechanism has a resilient mechanism cover, to be attached in use to a book-shaped binder cover, and two oppositely articulately connected, moveable, ring-rail or ring-coil members carrying ring portions which form rings jointly in pairs, resiliently supported in the mechanism cover to be actuated by means of at least one movable actuating member to open and close the rings. According to the invention, the actuating member is adapted for movement about an axis of rotation aligned substantially perpendicular to the mechanism cover and is provided with a gear coupling it to move the ring-rail or ring-coil members.

Abstract: A sliding switch for manually controlling a socket-plug timer which is protected so as to be at least splash-proof to water, including a housing constituted of at least two parts, which is sealed through the intermediary of a sealing strip squeezed in between the joining locations of the housing parts. One of the housing parts is provided in the region of the joining parts with an access or through-opening which is open towards the sealing strip for a preferably round actuating pusher of the sliding switch, and in which the sealing strip includes a ring-shaped formation in the region of the access opening, through which the actuating pusher is sealed with respect to the access opening.

Abstract: An electrodynamic loudspeaker having a cone diaphragm within which there is arranged a centrally located body which influences the acoustic radiation. This body is formed by an extension of the magnet core of the moving coil which extension is enlarged in the region of the mouth of the cone to form a partial covering of the cone chamber up to about half of the diameter of the cone mouth. The central part of the covering is approximately equal to one and a half times the diameter of the magnet core and forms a closed surface. In the remaining edge area of the covering there are axially arranged passages, the cross-sections of which occupy approximately one-half of this edge area.