DEVICE FOR THE PNEUMATIC AUTOMATIC ACTUATION OF VENTILATION FLAPS

Abstract: The device which is particularly for installations for the escape of smoke and heat in response to fracture of a glass container (14) in response to a preset temperature, has two pressure-fluid cartridges (1, 2) each comprising a piercing piston (3, 4) as an energy carrying unit for opening the flaps and having discharge pressure chambers (16, 17) which are associated with the pressure-fluid cartridges (1, 2) and can be connected to actuating elements of the ventilation flaps. Associated with the discharge pressure chambers (16, 17) is a safety valve (15) which controls one or more pressure-relief passages (20, 19, 21).

Description: The invention relates to a device for the pneumatic automatic actuation of ventilation flaps and ventilation louvres in installation for the escape of smoke and heat, having two pressure-fluid cartridges, each comprising a piercing piston, as an energy carrying unit, and having discharge pressure chambers associated with the pressure-fluid cartridges and able to be connected to actuating elements of the ventilation flaps. Automatic actuating devices of the above-mentioned type are used, in particular, to open ventilation flaps in the event of an outbreak of fire and must be capable of operation in various temperature ranges. The energy carrying unit must be designed so that even at a low temperature of -20°C for example, an adequate pressure is available to open the ventilation flaps. Because of the compressibility of the pressure fluid, however, in the case of automatic actuation at very much higher temperatures, for example +110°C, pressures are released which overtax the whole system. It is the object of the present invention to provide a device of the type mentioned at the beginning wherein a reliable actuation of ventilation flaps is ensured in low temperature ranges and the whole system is not overtaxed in higher temperature ranges. DE-A-3429178 describes an opening device for smoke and heat offtake flaps having two pressure fluid cartridges each associated with a piercing piston having a piercing-piston housing as an energy carrying unit and having fluid pressure chambers which are in fluid connection with the pressure-fluid cartridges and can be connected to actuating elements of the ventilation flaps, a piercing-piston locking unit holding the piercing-piston in a locking position, said unit including a locking member disposed in a passage in an intermediate member lying between the two piercing-piston housings and held by these, and a breakable glass container breakable at a preset temperature and positioned remote from the energy carrying unit to activate the locking unit in the sense of unlocking. A device in accordance with the present invention is characterized in that said intermediate member is formed as safety valve which works depending on pressure and which controls the fluid pressure in one or more pressure-relief passages, the safety valve having a pressure relief passage communicating both said fluid pressure chambers with a control valve disposed to one side of said energy carrying unit and formed as part of said piercing-piston locking unit, said breakable glass container being positioned at the end of said control valve remote from said energy carrying unit. In the device according to the invention, the safety valve opens pressure-relief openings, when a preset critical operating pressure is exceeded, until an operating pressure has become established which does not overstress the whole system. As a result of the safety valve controlling the operating pressure, assurance is provided, in the device according to the invention with two pressure-fluid cartridges, that, in the event of automatic actuation in the low temperature range of -20°C, a sufficient pressure to actuate the pressure cylinders of the ventilation flaps is available as a result of the discharge of both cartridges and at higher temperatures, excess compressed air is blown off when both cartridges are discharged. Further details of the invention are apparent from the drawings and the following detailed description given by way of example. In the drawings: FIG. 1 shows a cut away illustration of an embodiment of the device according to the invention in longitudinal section; and FIG. 2 shows a diagrammatic side view on the line II-II in Figure 1. With reference to the drawings, the device consists of a first pressure-fluid cartridge 1 and a second pressure-fluid cartridge 2 as an energy carrying unit, with each of which cartridges there is associated a piercing piston 3 or 4 with piercing needles 5 and 6. The piercing pistons 3 and 4 are each disposed in piercing-piston housings 7 and 8 respectively and are each loaded, at their ends opposite to the piercing needles 5 and 6, by a compression spring 9 supported on the piercing-piston housing. The piercing pistons 3 and 4 are held in their locked position by a locking unit which comprises a locking rod consisting of a 5/2-way spool valve member 10 and a pin 11, as well as a locking member 23. The 5/2-way spool valve member 10 has, at its end remote from the piercing piston 3 of the first pressure-fluid cartridge 1, a shank-like extension 13 in which a breakable glass container 14 engages. The glass container 14 breaks at a preset temperature as a result of which the locking device is activated in the sense of unlocking. According to the invention, fluid pressure chambers 16, 17 of the device can be relieved through a safety valve 15 in that, by means of the safety valve 15, the fluid pressure chambers 16 and 17 in fluid connection with the first and second pressure-fluid cartridges 1, 2 are connected to the safety valve 15 through pressure-relief bores 19, 20. In the example of embodiment illustrated in Figure 1, the pressure-relief bores 19, 20 consist of the bores 19, 20 which extend rectilinearly in the piercing-piston housings 7, 8 substantially perpendicular to the central longitudinal axes 18 of the piercing pistons 3, 4 and are mutually aligned with one another and which are connected to one another through a pressure-relief bore 21 formed inside the safety valve 15 disposed as an intermediate member between the two piercing housings 7, 8. Above the pressure-relief bore 21, the safety valve 15 comprises a passage 22 for a locking member 23 of the piercing piston 4 so that the safety valve 15 can be disposed between the two piercing pistons 3 and 4 and held by these in an extremely space-saving manner. The valve body 15′ of the safety valve 15 for blowing off excess compressed air, is disposed centrally in the pressure-reilief bore 21 of the safety valve 15.

Claims: A device for the pneumatic automatic actuation of ventilation flaps and louvres in installations for the escape of smoke and heat, having two pressure-fluid cartridges (1, 2) each associated with a piercing piston (3, 4) having a piercing-piston housing (7, 8) as an energy carrying unit and having fluid pressure chambers (16, 17) which are in fluid connection with the pressure-fluid cartridges (1, 2) and can be connected to actuating elements of the ventilation flaps, a piercing piston locking unit (10, 13, 11, 23) holding the piercing-piston in a locking position, said unit including a locking member (23) disposed in a passage in an intermediate member (15) lying between the two piercing-piston housing (7, 8) and held by these, and a breakable glass container (14) breakable at a preset temperature and positioned remote from the energy carrying unit to activate the locking unit in the sense of unlocking, characterized in that said intermediate member (15) is formed as a safety valve (15) which works depending on pressure and which controls the fluid pressure in one or more pressure-relief passages (20, 19, 21), the safety valve (15) having a pressure relief passage (21) communicating both said fluid pressure chambers (16, 17) with a control valve (10) disposed to one side of said energy carrying unit and formed as part of said piercing-piston locking unit, said breakable glass container being positioned at the end of said control valve remote from said energy carrying unit. A device as claimed in claim 1, characterized in that rectilinear bores (19, 20) extending substantially perpendicular to the central longitudinal axes (18) of the piercing pistons (3, 4) are provided one in each of the piercing-piston housings (7, 8) for the pressure relief, and the bores (19, 20) are mutually aligned with one another and connected to one another through said pressure-relief passage (21) provided in the safety valve (15).

Inventors: HUSGES, HANS-DIETER, RIDDERMANN, PETER
Applicants: COLT INTERNATIONAL HOLDINGS A.G.
Application year: 1987
Main classification: A62C2
IPC codes: A62C2