JPH033500B2 - - Google Patents

Description

Detailed description of the invention [Industrial field of application] The invention relates to a cylinder-piston unit having a source of compressed gas, which additionally communicates with the interior space of a breathing bag by means of a compressed gas conduit. The present invention relates to a circulatory respiratory protection device for overpressure operation, which supplies a source of compressed gas to an auxiliary device which causes a pressure increase in the respiratory circuit by the movement of the respiratory bag.

BACKGROUND OF THE INVENTION A circulatory respiratory protection device of this type is known from DE 31 05 637 A1.

In known cyclorespiratory protection devices with overpressure operation, it is ensured that during their use an overpressure prevails in the respiratory circuit both in the exhalation phase and in the exhalation phase.
This overpressure prevents the ingress of ambient air that could contaminate the device and harm the user of the device during use of the device. If a leak occurs in the respiratory circuit, the overpressure will only result in a flow of gas from inside the respiratory circuit to the outside into the ambient atmosphere.

However, with known respiratory circulatory protection devices, this means unnecessary tension for the user, since an overpressure is created in the respiratory circuit even during the exhalation phase. That is, the overpressure required for tightness in the direction of the protection of the person carrying the device is already present in the mouthpiece or in the entire mask (Vollmaske), which consists of, for example, crimped hoses, valves and recycling cartridges. Caused by flow resistance. The additional static overpressure places an additional burden on the person carrying the device, causing premature fatigue.

This also applies to the following known compressed gas respiratory protection device with overpressure in the breathing air according to DE 30 15 759, which is also designed as a circulation device. Here, a breathing bag arranged in the circuit is loaded with a prestressed spring from the outside, so that an overpressure is maintained in the circuit. From the oxygen pressure container, oxygen is supplied via an automatic lung device to a breathing bag which is manipulated by its movable end wall during evacuation. The automatic lung device is preceded by a non-return valve which is closed by the end wall when the breathing bag is completely expelled. This prevents a large amount of oxygen from escaping in the case of large leakages in the circuit and in the event of a reduction in overpressure when the breathing mask is removed.

However, it is not possible to reduce the overpressure each time during the exhalation phase with the intention of reducing the burden on the person carrying the device.

In another known cyclorespiratory protection device according to DE 31 05 637 A1, the expiratory line is connected to the inspiratory line via a CO ₂ absorber and a gas compensator. A compressed gas cylinder containing mainly oxygen is connected to the exhalation conduit. Bellows with rigid end walls are most suitable as gas compensators. The bellows is always subjected to the force of a cylinder-piston unit acting in the direction of volume reduction, and the piston of this unit connected to the end wall of the bellows absorbs compressed gas from a compressed gas cylinder (expands to medium pressure). ) is receiving pressure. The movement of the piston causes a sustained pressure increase in the bellows, which is sufficient for the desired overpressure in the entire respiratory circuit. By means not shown in detail, it is possible to vary the force acting on the bellows continuously or stepwise, thereby adapting the overpressure in the circuit to the existing working conditions and selectively disabling the respiratory protection device. Can be adjusted to reduced pressure operation and overpressure operation.

The force selected and regulated for each use is always active and produces a continuous pressure in the respiratory circuit by means of the piston, so that this pressure also acts during the inspiration phase as well as during the expiration phase. However, even during exhalation, the user has to build up pressure to overcome the flow resistance in the exhalation valve, conduit and CO ₂ absorber. The user is subjected to unnecessary additional strain during exhalation due to the additional overpressure.

[Problem to be Solved by the Invention] It is an object of the present invention to improve a circulatory respiratory protection device of the type described above in such a way that overpressure in the respiratory circuit occurs only during the inspiratory phase and not during the expiratory phase. It is to be.

[Means for Solving the Problem] This problem is solved by providing a sensor attached to a breathing bag and connected to a measuring circuit in order to detect the respiratory phase, and a measuring circuit under the cooperation of the sensor. This is achieved by controlling a switching valve in the compressed gas line, which connects the auxiliary device consisting of a cylinder-piston unit to the compressed gas line during the inspiration phase and disconnects this connection during the exhalation phase.

With the configuration of the circulatory respiratory protection device according to the present invention,
It becomes possible to control the pressure state in the respiratory circuit dependent on the respiratory phase. The sensor for detecting the respiratory phase is attached to the respiratory bag, but if the sensor is only capable of detecting the alternation between the inspiratory and expiratory phases, it can be placed anywhere in the respiratory circuit. It may be placed in

According to the invention, the compressed gas conduit is connected to the auxiliary device by means of a switching valve only during the exhalation phase and is shut off during the expiration phase, while at the same time the auxiliary device and the breathing bag are connected to each other by means of a connecting tube. Since it is connected,
Pressure fluctuations in the supply line to the auxiliary device can be compensated for by the stroke movement of the breathing bag. It is also possible to connect the supply line to the auxiliary device with the free ambient atmosphere via a switching valve, with the compressed gas line cut off, so that in the event of pressure fluctuations during the exhalation phase, Gas can be vented from the supply pipe. However, this has the undesirable disadvantage that in each case unnecessary compressed gas, such as oxygen, is lost.

Advantageously, the sensor for detecting the respiratory phase can be designed as an electrical resistance path arranged in a guide member that is connected to the piston end wall. The detection of the respiratory phase can thereby be attributed to the measurement of the direction of movement of the rigid movable wall part of the breathing bag. The measurement signal evaluated by the measurement circuit is provided by the voltage drop along the measurement path, as detected by the measurement detector.

During the respiratory phase, due to the movement of the fixed guide member of the sensor forming the resistance path, the measured potential difference ΔV ₀ that can be extracted from the sliding contact advantageously changes by ΔV _E during the course of the inspiration phase and It changes by ΔV _A during the course of the phase. Here, both ΔV _A and ΔV _E have opposite signs, positive or negative, respectively, and decrease to zero near the end of the breath. The alternation between the inspiratory and expiratory phases also represents an alternation between an increase and a decrease in the retrievable potential difference ΔV ₀ .
In this way, a simple criterion is obtained as to when the alternation between the inspiratory and expiratory phases takes place, giving the measuring circuit an unambiguous criterion as to when a switchover of the auxiliary device must take place. .

If the extractable potential difference ΔV ₀ itself reaches a value of zero, this must be attributed to a leak in the respiratory circuit. In this case, it is desirable that an alarm device is activated.

An embodiment of the invention will be described in detail with reference to the drawings.

A circulatory respiratory protection device with overpressure operation has components forming a respiratory circuit, shown in a functional arrangement, on a support frame within an outer protective case. These are the breathing connection 1, the exhalation conduit 3, the regeneration cartridge 4 which combines the carbonic acid present in the exhaled breath, the breathing bag 5 and the inspiratory conduit 2.

Oxygen consumed during breathing is stored in oxygen cylinder 6,
From the valve 7 of the cylinder, the pressure reducer 8, a conduit 10 with an automatic lung device 9 and a dosing device 11 feeds the respiratory circuit after the breathing bag 5. An overpressure valve 12 after the regeneration cartridge 4 prevents the pressure in the breathing circuit from becoming too high.

The breathing bag 5 consists of a bellows 13 closed by a movable rigid end wall 14. The cylinder-piston unit 15 has a piston 16 in a cylinder 17, and a pressure chamber 18 is located above the piston 16.
, which is connected to the conduit 10 via a compressed gas conduit 19 . The compressed gas line 19 contains a solenoid valve 20 with which the compressed gas line 19 is closed, the line section 2 in front of the pressure chamber 18 being closed.
1 is separated from the compressed gas conduit section, in which case the pressure chamber can be connected to the breathing bag 5 via a conduit section 21 and a connecting tube 22.

The lower end face 23 of the piston 16 facing away from the pressure chamber 18 projects from the open cylinder 17 and is connected to the end wall 14 of the breathing bag 5 by a movable connection 24 .

Upper end wall 25 of the piston facing the pressure chamber 18
The sensor 26 is fixed to the guide member 31 in the axial direction. The sensor 26 is configured as an electrical resistance path, which is connected to an amplifier 28 on its input side. The current passing through the amplifier produces a voltage drop along the resistive path, which is taken from the existing sliding contact 27. The potential difference amplified by the amplifier 28 and processed by the transmitter 29 (change value ΔV _E during the inspiratory phase, change value ΔV _A during the expiratory phase)
and the measured value ΔV ₀ which can be taken from the interstitial contact of the respiratory phase yields the switching value of the solenoid valve 20. The respiratory phases, ie, inspiration and subsequent exhalation, create in each case repeated functions and pressure conditions in the respiratory circuit.

During the intake phase, the solenoid valve 20 opens and the pressure chamber 1
8 is connected to a conduit 10. The overpressure provided by the pressure reducer 8 in the conduit 10 enters the pressure chamber 18 and presses against the piston 16, causing the end wall 2 of the piston to
Move 5 downward. At the same time, the breathing bag 5 is compressed. Due to the relationship between the volume of the breathing bag 5 and the pressure of the piston 16, the end wall 2 of the piston is formed in the circulation path.
5 and the end wall 14 of the breathing bag 5. An overpressure forms during the entire inspiratory phase and prevents the entry of contaminated ambient air into the respiratory circuit. Simultaneously with the piston 16, the sensor 26 also moves in the direction of the arrow E, at which time the length of the resistance path for the sliding contact 27 changes, and the potential difference ΔV _E decreases (second
(see figure). At the end of the inspiration phase, when the breathing bag reaches a minimum inspiration volume and the potential difference ΔV _E =0, the solenoid valve 20 closes, thereby separating the compressed gas conduit 19 from the pressure chamber 18 . In this case, the pressure chamber 18
is connected to the breathing bag 5 via a conduit section 21 and a connecting tube 22. The overpressure created in the breathing circuit by the piston 16 is eliminated by pressure relief in the pressure chamber 18 .

With the onset of exhalation without overpressure in the breathing circuit, the breathing bag 5 inflates upwards and causes the end wall 14 to move accordingly. Sensor 26 moves in the direction of arrow A and the resistance path becomes longer again. During this period, the potential difference ΔV _A decreases until it reaches the value ΔV _A =0,
Therefore, ΔV ₀ reaches the set value and switches. At the end of expiration, when the potential difference ΔV _A = 0, the solenoid valve 2
0 is switched over again, so that a new overpressure can build up in the circuit for the subsequent intake phase.

If the breathing circuit leaks strongly, the overpressure in this circuit is completely reduced. When the solenoid valve 20 is open, the oxygen pressure still present in the compressed gas conduit 19 causes the breathing bag to be further compressed and deflated, causing the contact point E ₀ to move further down in the direction of the arrow E;
When the potential difference V ₀ =0 at the shortest resistance path, the solenoid valve 20 closes. Since the breathing bag 5 has no inherent elasticity, it remains in its minimum state, the solenoid valve 20 remains permanently closed to the compressed gas conduit 19, and at the same time the alarm device 30 is activated. The device bearer can now use the circulatory respiratory protection device at normal pressure. Oxygen supply is normally provided by conduit 10. When the leak point is closed, the breathing bag 5 is refilled and the breathing circuit automatically switches back into overpressure operation.

[Brief explanation of the drawing]

FIG. 1 of the drawings is a schematic diagram of a circulatory respiratory protection device according to the invention, and FIG. 2 is a diagram showing a detector with a potential difference taken therefrom. DESCRIPTION OF SYMBOLS 1...Respiration connection part, 2...Inhalation conduit, 3...Exhalation conduit, 4...Regeneration cartridge, 5...Respiration bag, 6...Oxygen cylinder, 7...Cylinder valve, 9
... pressure reducer, 9 ... automatic lung device, 10 ... conduit,
11... Metering device, 12... Overpressure valve, 13... Bellows, 14... End wall, 15... Cylinder-piston-unit, 16... Piston, 17...
Cylinder, 18... Pressure chamber, 19... Compressed gas conduit, 20... Solenoid valve, 21... Conduit portion, 22
... Connection pipe, 23 ... Lower end surface of the piston, 24
... Connection portion, 25 ... Upper end wall of the piston, 2
6...sensor, 27...sliding contact, 28...amplifier, 29...transmitter, 30...alarm device, 31...guiding member.

Claims (1)

Claims: 1. A compressed gas source 6 consisting of a cylinder-piston unit which additionally communicates with the interior space of the breathing bag 13 by means of a compressed gas conduit 19 and which is controlled by the movement of the breathing bag. In a circulatory respiratory protection device for overpressure operation, supplying compressed gas to an auxiliary device 15 that causes a pressure increase in the respiratory circuit, it is attached to the breathing bag and connected to the measuring circuit 28, 29 for detecting the respiratory phase. sensor 2
6 is provided, in which a measuring circuit 28, 29 is connected to the switching valve 2 in the compressed gas line 19 under the cooperation of the sensor.
0, the valve connects an auxiliary device 15 consisting of a cylinder-piston unit to a compressed gas conduit 19 during the inhalation phase, and cuts off this connection during the exhalation phase. Device. 2. The sensor 26 for detecting the respiratory phase contains an electrical resistance path arranged in the guide member 31 connected to the piston end wall 25, from which a potential difference ΔV ₀ can be extracted, which potential difference is During the inspiratory phase, ΔV _E changes, and during the expiratory phase, ΔV _A
ΔV _E and ΔV _A each have an opposite sign, positive or negative, and the measuring circuits 28, 29 indicate that the auxiliary device 15 switches in the transition phase between the inspiratory and expiratory phases, respectively. ,
2. The circulatory respiratory protection device according to claim 1, wherein ΔV _E and ΔV _A are designed to change sign after reaching a value of zero.