Abstract: To enhance or ensure personal security against an attack, threatened attack or believed attack, a flexible drop net, preferably made of ball chain elements (26, 30), connected at nodal points (28) is retained against and/or partly within a dropped or double-wall ceiling (2, 3). The drop net is held against the ceiling by a pull-up or raising chain, preferably also a ball chain (13), and pulled up by a lifting mechanism (18), for example rollers, engageable with a pull chain and operated by a motor, if desired. A triggering mechanism is coupled to a retention rail or plate (5) holding the drop net or at least a portion thereof within the double ceiling, against the drop rail or plate, or thereabove. Upon a triggering impulse being applied to an electromagnet (6), a linkage (7, 9) releases the drop rail or plate, thus dropping the flexible net over an attacker; any other persons, who are also within the range of the net, will likewise be trapped thereunder, without, however, causing injury.

Abstract: A throttling device is located in a venting pipe or in a pipe section such as a flue gas pipe or conduit arranged between a boiler and a flue or chimney. The flap is held in a pipe section for removal out of the respective pipe either by tilting or by pulling the flap out. For this purpose the pipe section has a slot which is about semicircular and which, in operation, is covered by a ring section or sector. The throttle flap may be pulled out of the pipe section together with the ring section and with its adjustment drive whereby cleaning of the pipe or conduit is substantially facilitated. Heat losses through the flue are avoided when the throttle flap is closed.

Abstract: A furnace, for example of the home-heating type, has heat storage elements located in a combustion gas chamber of the furnace, the heat storage elements being placed in a path of flow of combustion gases to increase flow resistance to the combustion gases. The heat storage elements are of such size that they can be inserted into the combustion gas chamber and removed therefrom through door openings normally available in the furnace, for example to change over the furnace from liquid to solid fuels, for cleaning or the like. The storage elements preferably are metal-jacketed bodies of refractory material, for example of clay. If the furnace has a water jacket for heating of water, the clay bodies are placed against the water jacket surface, with the metal jacket of the clay bodies perforated at the side facing the water jacket. A group of such heat storage elements may be commonly supported on a carrier for removal as an assembly.

Abstract: A spider socket connector is fixed at one end of a rod of which the other end is fixed to a foot in which a single rear T support is pivoted and settable at several different inclinations. The setting is releasable by virtue of a slip joint, by simply pulling up on the T support. The front legs and the front seat strut bars fitting into the spider form an X concave to the front so as to allow convenient leg room. A seat fabric is suspended between the T support and outwardly extending brackets fitted in the ends of the strut bars, these brackets also serving as handles. The various elongated members can be packed parallel without completely detaching them.