AU7268200A

AU7268200A - Warning device for a compressed air breathing apparatus

Info

Publication number: AU7268200A
Application number: AU72682/00A
Authority: AU
Inventors: Torsten Haase; Thomas Hanisch; Peter Kling; Dieter Lubkoll
Original assignee: MSA Auer GmbH
Current assignee: MSA Auer GmbH
Priority date: 1999-07-29
Filing date: 2000-07-18
Publication date: 2001-02-19
Also published as: DE19936893A1; DE19936893C2; WO2001008752A1; EP1200157A1; ZA200200492B; CA2379697A1

Description

Description Warning device for a compressed air breathing apparatus The invention relates to a warning device for a compressed air breathing apparatus comprising a movement sensor and a sound generator triggered by a microprocessor in the event of motionlessness of the user, wherein a monometer can be connected via a pressure line to an breathing tank of the compressed air apparatus under pressure. Warning devices of this type are conventionally switched on manually by the device wearer before use. If the movement sensor registers a motionlessness of the device wearer initially a preliminary alarm is triggered for the user himself and after a time delay a main alarm is triggered to summon aid from third parties. Comfort, forgetfulness or sometimes even the disruptive noises in the event of frequently occurring preliminary alarm mean that the warning device is sometimes not switched on and therefore the safety, but also the competence of the relevant person is not guaranteed. To solve this problem as is known the warning devices are designed with a Hall-effect switch which can be switched via a key. The removed and centrally managed key should facilitate control of the activation of the warning device by third parties. This system is complex and does not provide complete security in relation to the actual activation of the warning device. In the known warning devices for compressed air breathing apparatus calculation and display of the remaining available time of the compressed air breathing apparatus or of the device wearer is also performed on the basis of the volume of the breathing tank, so for compressed air breathing apparatus with different capacities different or differently programmed warning devices have to be used. The known warning devices are also designed for 2 specific warning thresholds which do not always satisfy the existing requirements. The object of the invention is therefore to disclose a warning device of the type mentioned at the outset, the data of which can be altered in accordance with the respective requirements for sounding the alarm and is reliably switched on in the operational state of the compressed air breathing apparatus and can be variably and arbitrarily refitted in relation to fixing of the remaining available time irrespective of the volume of the respective breathing tank. The object is achieved according to the invention by a warning device for a compressed air breathing apparatus designed in accordance with the features of claim 1. An essential feature of the invention consists initially in that, proceeding from the conventionally used mechanical manometers and the electronic warning units equipped with a sound generator for signalling a motionlessness of the user, the manometer and the electronic system are combined in a unit and, more precisely, via a pressure sensor incorporated into the compressed air supply in the manometer, the electric signals of which processed in a signal processing component are supplied to a microprocessor in order to activate the electronic system and in particular the movement sensor and the corresponding sound generator. The warning device is consequently independent of the user in operation as soon as the compressed air breathing apparatus is used. Accidental or conscious non-commissioning of the warning device is therefore reliably ruled out. Furthermore, the pressure sensor also acts as a second pressure measuring device independent of the manometer. The respective pressure prevailing is digitally displayed on a display.

3 In conjunction with the microprocessor and the data input therein the pressure sensor serves to activate the sound generator when certain - graduated - pressure values in the breathing tank are not attained. The user is pre-warned in good time and repeatedly owing to the triggering of the acoustic signals, for example when 150 bar, 100 bar and 60 bar are reached. A further function of the pressure sensor in conjunction with the microprocessor and a clock integrated in the device finally consists in, proceeding from the respective pressure prevailing in the breathing tank and the repeated measurement of the drop in pressure per unit of time i.e. the instantaneous air consumption by the user, calculating the maximum remaining available time to the device wearer and displaying this on the display at short time intervals. This type of calculation of the remaining available time based on the values transmitted by the pressure sensor allows the warning device according to the invention to be used for all tank sizes conventional in compressed air breathing apparatuses. An important feature of the invention of the electronic component of the warning device also consists in the incorporation of an infrared interface connected to the microprocessor for inputting data into the microprocessor in order in this way to fix the required alarm thresholds for pressure and temperature or also the switching on of a Hall-effect switch for optional activation of the electronic system via a key. In an advantageous development of the invention the infrared interface designed as an IR transceiver is coupled to a telemetry, so the data can also be input from a central operation point and the stored data can be read out from there. Therefore, with the solution according to the invention a warning device variable in its warning thresholds is provided which meets the highest requirements in relation to the safety of the user 4 and can be used for all sizes of compressed air breathing apparatus and can also be readily refitted as the conventional manometer merely has to be changed for the warning device according to the invention. Further features and advantageous configurations emerge from the sub-claims and the following description of an embodiment of the present invention given by way of example. An embodiment of the invention is described in more detail with the aid of the drawings in the single figure of which a block diagram of a warning device attachable to a compressed air breathing apparatus is shown. The warning device consists of a robust housing 2 comprising function keys 1 and in which a mechanical tube spring manometer 3 for analogue pressure display and an electronic measuring and warning unit are integrated. The electronic unit comprises a pressure sensor 4 formed, for example, from a diaphragm provided with a wire strain gauge loaded, like the manometer 3 directly by the compressed air in an breathing tank (not shown). The compressed air sensor 4 is connected via a signal processing component 5 to a microprocessor 6 and a display 7. In this way the pressure in the breathing tank is measured both mechanically and electronically and is displayed in analogue form on the one hand and digitally on the other. Even if a measuring unit fails there is always the measured value of the other unit as warning signal. A temperature sensor 8, a movement sensor 9 and a real time clock 10 connected to the microprocessor 6 are also housed in the housing 2. An LED status display 11 and a sound generator 12 are also connected to the microprocessor 6. All current consumers 11 of the electronic system are supplied by a battery 13 with the necessary energy. The real time clock 10 also has an auxiliary battery 10a so the function of the clock is not impaired in the 5 event of an interruption to the energy supply, for example upon a battery change. As soon as the compressed air breathing apparatus is activated with the breathing tank valve open (not shown) there is a pressure at the pressure sensor 4 and the electronic unit of the warning device is automatically activated, i.e. without any action on the device wearer's part by the electrical signals produced as a result and in conjunction with the signal processing component and supplied to the microprocessor 6, in order to trigger an alarm at the sound generator 12 when a certain pressure in the breathing tank shown on the display 7 is not attained, when a specific temperature detected by the temperature sensor is exceeded or when the movement sensor 9 reacts via the microprocessor. The pressure is displayed on the display 7 at the start of initial operation of the compressed air breathing apparatus or of the warning device. The respective maximum remaining available time is shown on the display 7 in the following period. This time remaining to the user until the air available in the breathing tank is fully consumed is calculated on the basis of the respective - actual pressure in the breathing tank and the air breathed by the user in a specific unit of time measured using the real time clock. The instantaneous air consumption per unit of time (instantaneous breathing) is remeasured every 30 seconds in order to display the respective remaining available time to the device wearer in this time interval. This type of calculation of the remaining available time on the basis of the pressure and of the drop in pressure per unit of time allows the warning device to be used irrespective of the size of the respective breathing tank, so any compressed air breathing apparatus can be refitted with the warning device.

6 The microprocessor 6 connected to the movement sensor 9 and the real time clock 10 is programmed in such a way that upon motionlessness of the device wearer, i.e. when the movement sensor reacts, a pre-alarm is initially triggered and at a certain interval a main alarm is triggered at the sound emitter 12. The microprocessor 6 can also induce the emission of an acoustic alarm via the sound generator 12 at a certain pressure of, for example 60 bar, or also at a plurality of different pressures, for example at 60 bar, 100 bar and 150 bar. The temperature value for triggering the temperature alarm can also be adjusted via the microprocessor or the preliminary alarm can be switched off upon the reaction of the movement sensor 9. To read in certain data from pressure and temperature values and the time intervals or instances for setting the alarm triggering via a PC 17 with data stored therein, an IR transceiver 14 (infrared interface) is integrated in the warning device via which the respectively desired data can be read into the microprocessor 6. The instantaneous data available from the warning device can equally be read out via the IR transceiver 14. As can be seen from the drawing the warning device also has a Hall-effect switch 15 with a key, by the removal of which the warning device can also be activated via the microprocessor 6. The Hall-effect switch 15 is activated via the IR transceiver 14, the function of the pressure sensor- of commissioning the warning device 5 no longer existing in this case, but the pressure gauge continues to retain its function of determining pressure and of determining the drop in pressure per unit of time in conjunction with the time measurement for triggering specific pressure alarms or for calculating the remaining available time. The drawing also indicates with the reference numeral 16 a telemetry connected to the infrared interface via which the data of the warning device can be ascertained by radio by an external operational control centre or specific data can also be read into 7 the device in this way. It is therefore possible to control the deployment of the device wearer via the interface in the warning device and to initiate necessary measures, for example trigger the main alarm as a demand to leave the region of deployment. The described warning device represents only one embodiment of the invention described by way of example and not limiting the subject of the application. Numerous modifications in relation to the specific design of the warning device and its individual components are possible in the context of the basic idea of the invention consisting in the combination according to the invention of a manometer with a pressure sensor and the electrical signals therefore supplied to a microprocessor for commissioning the warning device, calculating the remaining available time and triggering an alarm as a function of specific pressure and temperature details which can be read in via an IR transceiver and time details as warning thresholds.

8 List of reference numerals 1 function keys 2 housing 3 tube spring manometer 4 pressure sensor 5 signal processing component 6 microprocessor 7 display 8 temperature sensor 9 movement sensor 10 real time clock 10a auxiliary battery 11 LED status display 12 sound generator 13 battery 14 IR transceiver (infrared interface) 15 Hall-effect switch 16 telemetry 17 PC

Claims

1. Warning device for a compressed air breathing apparatus comprising a movement sensor and sound generator triggered by a microprocessor in the event of motionlessness of the user, wherein a monometer can be connected via pressure line to a pressurised breathing tank of the compressed air breathing apparatus, characterised in that a pressure sensor (4) generating electrical signals as a function of the respective pressure is connected to the compressed air inlet in the monometer (3) and is connected via a signal processing component (5) to the microprocessor (6) to which a real time clock (10) is connected in order to activate the warning device as a result of the electrical pressure signals and to trigger an alarm of the sound generator (12) owing to limit values of the pressure being exceeded or not being attained and the temperature detected by a temperature sensor (8) or a preliminary alarm or main alarm or a main alarm only owing to a motionlessness of the user ascertained by the movement sensor (9), as a function of data read into the microprocessor (6), via an infrared interface (14) integrated in the warning device, and to measure the instantaneous pressure in the breathing tank at specific time intervals in conjunction with the real time clock (10) and the drop in pressure per unit of time and to calculate the user's/compressed air breathing apparatus's remaining available time therefrom.

2. Warning device according to claim 1, characterised in that a Hall-effect switch (15) with key and connected to the microprocessor (6) and activatable via the infrared interface (14) is provided in order to commission the apparatus thereby while eliminating the contact ON-function of the pressure sensor (4).

3. Warning device according to claim 1 and 2, characterised in that it comprises a display (7) connected to the microprocessor 10 (6) for displaying the instantaneous pressure values in the breathing tank, the remaining available time calculated on the basis of the instantaneous breathing and the temperature.

4. Warning device according to any of claims 1 to 3, characterised by an LED status display (11) integrated therein.

5. Warning device according to claim 1, characterised in that an auxiliary battery (10a) is associated with the real time clock (10) for maintaining the uninterrupted operation of the clock even in the event of an interruption to the power supply of the apparatus provided by a battery (13).

6. Warning device according to any of claims 1 to 5, characterised in that the infrared interface is formed by an IR transceiver (14) and is connected to the interface of a PC (17) for the reading-in and reading-out of data, in order to read and optionally graphically process stored data or to alter alarm thresholds for pressure and temperature in terms of level and time or to turn the warning device off or to activate the Hall effect switch.

7. Warning device according to any of claims 1 to 6, characterised by a telemetry connected via the infrared interface (14) to the device for remote transmission of data from and to the microprocessor. 13 Abstract Warning device for a compressed air breathing apparatus A warning device for a compressed air breathing apparatus comprises a mechanical manometer (3) and a pressure sensor (4) incorporated in the compressed air line thereof and connected via a signal processing component (5) to a microprocessor (6). The microprocessor is connected to a movement sensor (9), a temperature sensor (8) and a real time clock (10) and is connected on the other hand to a sound generator (12) and a display (7). The pressure sensor serves to activate the electronic system of the device independently of the user and to trigger an alarm when a certain minimum pressure is reached, and in conjunction with the real time clock and the microprocessor to calculate from the instantaneous pressure in the breathing tank and the instantaneous drop in pressure per unit of time, irrespective of the respective tank size, the remaining available time and to display it. The microprocessor is connected to an infrared interface (14) via which data for adjusting or amending warning thresholds can be input and data from the device can easily be read out (figure).