Portable fire detector

Abstract

A portable fire alarm device comprising fire detecting means and alarm means powered from a self-contained power supply. The power to the detector and alarm is through a normally closed switch of the type such as a mercury switch which may be opened by tilting the device to a predetermined angle from the vertical so that the alarm may be shut off.A second normally open switch of the mercury type connects the power supply directly to the alarm device and is so oriented that tilting the device to a predetermined angle from the vertical closes said switch and energizes the alarm to test the condition of the battery.

Description

Claims

1. A portable fire detector, comprising a base and an upwardly projecting member, fire detecting means in said upwardly projecting member, and signalling means associated therewith, means responsive to the detection of fire by said fire detection means to energize said signalling means through a first circuit that includes circuit latching means, means responsive to the tilting of said device a predetermined angle away from and back to the vertical to energize and de-energize respectively said signalling device through a second circuit path, and means responsive to the tilting of said device away from the vertical a predetermined amount when the signalling device has been energized by the detector to de-energize the signalling device by breaking the first circuit.

2. A portable fire detector, comprising a base and an upwardly projecting member, fire detecting means on said upwardly projecting member, signalling means for connection to a power source, means responsive to the detection of a fire by said fire detecting means to complete a first circuit from said signalling means to the power source, circuit latching means for thereafter maintaining said circuit, means responsive to the tilting of the upwardly projecting member away from the vertical to break said first circuit, means responsive to the tilting of the upwardly projecting member away from the vertical to complete a second circuit path from the power source to the signalling means, said second circuit being maintained only while the upwardly projecting member is disposed at an angle from the vertical and being broken when the upwardly projecting member is returned to the vertical position.

3. In a portable fire detector unit comprising a base, a member projecting upwardly from the base, a fire detecting device disposed on top of said member, signalling means for connection to a power source, and electrical circuitry responsive to the detection of the presence of fire by the fire detecting means to complete a circuit path between the power source and the signalling means, the improvement comprising a first gravity operated switch connected in said circuit path and being so mounted as to be normally closed when the unit is in the normal upright position and to open when the unit is tilted a predetermined angle away from the vertical, thereby breaking the circuit path to the signalling means and said circuit holding means and a second gravity operated switch connected to provide a second circuit path between the power source and the signalling means, and being so mounted as to be open when the unit is in its normal upright position and closed when the unit is tilted a predetermined angle from the vertical, whereby after said signalling unit is energized through the first circuit path, it may be deenergized by tilting the unit away from the vertical to an angle such that the first gravity operated switch is opened and returning it to the upright position, and the signalling device may be energized independently of the detection of a fire for test purposes by tilting said unit away from the vertical to an angle such that the second gravity operated switch is closed.