A static fluid system for detecting a selected change in an ambient condition. The system includes an elongate closed fluid line having a selected absolute pressure and pressure means to maintain the line pressure. Sensing means in the line respond to selected changes in ambient conditions to open the line and change the line to ambient pressure. Signal means responds to the change in line pressure, and flow restricting means in the line maintains the line pressure under normal ambient conditions and precludes re-establishment of the line pressure when the sensing means is activated to open the fluid line.
BACKGROUND AND GENERAL DESCRIPTION
This application is a continuation-in-part of my copending application, Ser. No. 368,609 filed June 11, 1973 entitled "DETECTION SYSTEM", now abandoned.
A pneumatic temperature sensitive system has a hollow detector member laid in a loop for instance in the room. The detector member is pressurized so that when the critical temperature is reached the detector member bursts and its interior space is depressurized. The detector member is connected with a pressure sensor to produce an electrical or other signal when the pressure falls so that further equipment may be activated.
A system for detecting changes in load on terrain and actuating an alarm in response thereto including a fluid system, a pressure-sensitive device in the fluid system having a first pressure signal output responsive to a load on a terrain, a second pressure signal output generating device responsive to said first pressure signal output, an alarm and a pressure-sensitive switch connected to said alarm, said switch being responsive to the second pressure signal output to actuate the alarm.
A fire prevention device that allows a fire prevention fluid obtained from a fluid source to flow therethrough when subject to a melting temperature includes a housing having a fluid inlet and a fluid outlet. A conduit is disposed between the fluid inlet and the fluid outlet, and a meltable material is disposed within the conduit. The meltable material sufficiently melts when subject to a temperature of at least the melting point of the meltable materials so that the fluid can exit via the conduit through the fluid outlet.
The invention relates to an apparatus for fire-fighting comprising a fire-extinguishing nozzle (4) connected to an extinguisher fluid supply (3) via a pipe (2) and comprising an alarm device (5) which delivers a warning signal at the beginning of a fire-extinguishing process. In such an apparatus the risk of leaks occurring is reduced and effective alarming of the surroundings at the beginning of the fire-extinguishing process is ensured according to the invention by the fact that the alarm device (5) comprises a pressure-actuatable switching device connected to the pipe (2) which triggers the warning signal in the event of an increase in the pressure prevailing in the pipe (2).
A temperature sensor has a flexible nylon tube connected by a fluid-tight coupling to a metal bellows within a metal housing. The interior of the tube and bellows is filled with a pressurized liquid whose critical temperature corresponds to a threshold temperature to be sensed. The pressurized liquid holds the bellows extended, holding an actuating piston back against the action of a spring. When the threshold temperature is reached, the liquid in the tube must boil and ruptures the tube, causing the bellows to collapse and the actuating piston to move. A projecting actuator then mechanically initiates a response such as the closing of a damper in an air-conditioning duct.
