GB2327753A

GB2327753A - Firefighter's torch

Info

Publication number: GB2327753A
Application number: GB9812987A
Authority: GB
Inventors: Paul Murley; Barry Alexander Hutchinson
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-07-07
Filing date: 1998-06-17
Publication date: 1999-02-03
Anticipated expiration: 2018-06-17
Also published as: GB2327753B; GB9812987D0; GB9714221D0

Abstract

A fire fighter's hand lamp comprises red or orange LED's 3 as a source of illumination that can penetrate smoky atmospheres, an ultrasonic measuring system 6 to detect obstructions and doorways, infra red detection means 4,5 to detect occupants in a building and or the seat of a fire, and means to detect when the firefighter stops moving. Displays are provided to indicate the location of any detected obstacles and the direction and intensity of heat sources. The light source 3 is flashed if movement is not detected within a given period. The lamp is switched on by removal of a key and is attached to the user by a strap.

Description

FIREFIGHTERS HAND LAMP This invention relates to a hand lamp for use by firefighters in smoke filled compartments.

The Fire Service uses a variety of hand lamps, but all use incandescent filament bulbs or sealed beams as the light source and emit white light. White light is not ideal in smoke because back reflection obscures detail and the short wavelength components do not penetrate due to diffraction and dispersion. Only the longer wavelengths of light, ie red and orange, penetrate any distance. This effect can he seen at sunset when only red light penetrates low level pollution. It is not good practice to filter white light to produce red light as efficiency will be severely compromised.

By using Light Emitting Diodes as the light source electrical energy is efficiently convened into red or orange light without wasted heat or the shorter wavelengths being produced.

Figure 1 shows a front view of the firefighters hand lamp.

Figure 2 shows a tdp view of the firefighters hand lamp.

Figure 3 shows a side view of the firefighters hand lamp.

Figure 4 shows a schematic diagram of the components of the firefighters hand lamp.

Referring to Figure 1 the firefighters hand lamp comprises a body (1) made of glass fibre reinforced plastic or any suitable material. The glass or plastic lens assembly (2) houses a number of high intensity light emitting diodes (3) as the light source, which are backed by a metal or metallised plastic reflector (not shown).

The front of the firefighters hand lamp houses high and low gain infra red detectors (4) and (5) which are used to detect body heat and fire respectively. Also housed on the front of the firefighters hand lamp is an ultrasonic transceiver (6) which transmits and receives ultrasonic signals as part of a system to measure distances of solid objects from the firefighters hand lamp.

Referring to figure 2 the top of the firefighters hand lamp houses a backlit liquid crystal digital display or a light emitting diode digital display (7) which displays the distance as measured by the ultrasonic transceiver (6) (figure I) and associated module. Also on housed on top of the firefighters hand lamp are light emitting diode bar graph displays (8) and (9) which indicate levels of heat detected by the high and low gain infra red detectors (4) and (5) (figure 1). Hidden inside the body of the firefighters hand lamp is a magnetic reed switch (10) which is activated by the removal of a magnetic key (11). A small light emitting diode display (12) indicates the charge state of the batteries (figure 3 (15)).

Referring to figure 3 the body of the firefighters hand lamp (l) has a handle (13) on top and a strap (14) underneath, hy this means the firefighters hand lamp can be either hand held or strapped to the forearm. The battery pack (15) can contain either dry cell or rechargeable batteries.

Referring to figure 4 all functions are operated by the single switched power supply (battery pack).

The lamp consists of a number of modules: 1. The power supply module.

2. The light source module.

3. The ultrasonic measurement module.

4. The infra red heat detection module.

5. The alarm module.

1. The power supply module consists of a battery pack, a magnetic reed switch and a charge status display.

If rechargeable batteries are used then there will also be a charging unit in the power supply module. The magnetic reed switch is a normally closed (or crossover) switch that will switch on the firefighters hand lamp when a permanent magnet key is removed, thereby preventing the lamp from being accidentally turned off.

2. The light source module consists of a number of high intensity light emitting diodes emitting light in the orange and/or red colours. To focus the beam of light the light emitting diodes are housed between a metal or metallised plastic reflector and a glass or plastic lens.

3. The ultrasonic measurement module consists of an ultrasonic transceiver that alternately transmits and receives ultrasonic sound, processing circuits and a digital display. By this means firefighters can estimate the dimensions and layout of compartments even when totally smoke logged.

4. The infra red heat detection module consists of two similar circuits, one very sensitive to low levels of heat (from human bodies), and the other to high levels of heat (from fire). Both circuits drive light emitting diode bar graph displays to indicate the intensity of the heat. The sensors are directional so that firefighters can establish the direction of the heat source.

5. The alarm module consists of a vibration detector, timer circuits and interruptor circuits. The vibration detector is used to reset a timer circuit. If the timer circuit is not reset (no signal from the vibration detector) the timer will time out and send a signal to the interruptor circuits which will flash the light source repeatedly until reset by the vibration detector and timer. This device is to supplement an existing device that firefighters attach to their breathing apparatus. The existing device is called an automatic distress signalling unit which automatically sounds an audible alarm in the event of a firefighter not moving for any reason. The firefighters hand lamp alarm would supplement this device by giving rescue crews a visuai signal and location as well as the existing audible signal. The alarm would also be useful if no breathing apparatus (and therefore no automatic distress signalling unit) was being worn.

Claims

1. A hand lamp producing red or orange light, with or without white light, incorporating a movement alarm, infra red detectors and ultrasonic measuring device.

2. A hand lamp as claimed in Claim 1 wherein the red or orange light is provided by light emitting diodes.

3. A hand lamp as claimed in Claim 1 or Claim 2 wherein the power for the light emitting diodes and other circuits is controlled by a constant current circuit.

4. A hand lamp as claimed in Claim 1 or Claim 3 wherein the movement alarm is provided by a motion detector resetting a timer circuit which interrupts the constant current circuit.

5. A hand lamp as claimed in Claim 1 or Claim 3 wherein the infra red detectors control a display to indicate the direction and relative intensity of heat sources.

6. A hand lamp as claimed in Claim 1 or Claim 3 wherein the ultrasonic measuring device controls a display to indicate the location of obstacles and clear ways.

7. A hand lamp as claimed in Claim 1 or Claim 3 wherein the power supply is monitored to give an indication of the reserve levels of power.

8. A hand lamp as claimed in any preceding claim wherein the power supply or any function is controlled by the removal of a key.

9. A hand lamp as claimed in any preceding claim wherein the principle means of holding the hand lamp is by means of a wrist or arm strap.