JPS58209362A - Breathing apparatus and operation thereof - Google Patents

Abstract

The present invention relates to improvements in power assisted positive pressure respirators for use in contaminated atmospheres. The respirator comprises a facepiece 1 having an inlet 3 connected to a pump unit 5 for supplying air to the facepiece which has been filtered by filter means 11 connected to the pump unit inlet. The facepiece is also provided with an outlet provided witha one-way valve 2 which is biased to its closed position and is openable when a predetermined pressure above atmospheric pressure is established within the facepiece. To maximise use of the filter means 11, a one-way inlet valve 13 is provided intermediate the pump unit 5 and the facepiece 1, conveniently at the inlet to the facepiece, which is closed during exhalation by the wearer to thereby cause the pump to be placed in a condition in which, although it continues to operate, no or substantially no air is moved thereby, so that during this period, no or substantially no air is drawn through the filter means 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in breathing apparatus used in polluted atmospheres.

Power-assisted breathing apparatus for use in dusty atmospheres are already known. Such breathing equipment is 1r
! In the first instance, the mask has a pump to supply filtered air from the atmosphere to a mask that covers at least the wearer's nose and mouth. Masks usually have an outlet valve which, under normal conditions, operates to maintain a slight positive pressure within the mask, for example 8
It is 125 Pascal at 51/min. The pump is set to deliver air to the mask at a rate of -foot expulsion, eg, about 1201/min, which is far above the wearer's average respiratory needs. The British 4@ and European standards are 120A'/rn for 4 hours to maintain a level of positive pressure within the mask even at typical peak inspiratory volumes.
Requires a minimum flow rate of i n. US standards require a minimum flow rate of 1131/min for a tight-fitting full-face mask and 1701/min for a "helmet and hood."

Since excess filtered air is constantly supplied to the mask,
Filters <f5 filters) will fail (cannot be used) much sooner than needed.

In fact, only about one-third of the filter's capacity is effectively used for breathing filtered air.

Filters for dust and other particulates have a relatively long life and can tolerate ineffectiveness such as those mentioned above, while filters for gases and benzene (these are usually made of granular activated carbon, silica gel, molecular weight materials or similar (made in the form of a metal container filled with materials) have a much shorter lifespan.

Therefore, their use in power-assisted breathing apparatus has until now been considered impractical. Therefore, many gas and 4-per-hyperventilation devices are unpowered, and the wearer uses the power of his or her lungs to draw air through the filter and into the mask.

The present invention provides a complete powered-assisted breathing apparatus which includes an inlet and an outlet, a mask for covering at least the mouth of the wearer, and a mask in the outlet.
a one-way valve operable to allow air to exit the mask ρ1 when a predetermined pressure difference is created between the exhalation of the wearer and a pump connected to said inlet for delivering air to the mask; 5, and a filter for passing the air ff1f" supplied to the mask by the pump, and ζ
In addition, a one-way valve is provided in the passage of air flowing from the pump to the mask, and this valve closes when the pressure on the downstream side of the valve becomes higher than the pressure on the upstream side of the valve during the wearer's exhalation. The pumps are arranged so that the pumps continue to rotate, but only draw air once in a while, or are turned off to suck no air at all.

The present invention further comprises: a mask having an inlet and an outlet for covering at least the mouth of the wearer; a one-way valve placed in the outlet and operable to allow air to exit the mask; A method of operating a power assisted breathing apparatus having a pump coupled to the inlet for delivering air to a mask, and a filter for treating air supplied to the mask by the pump. . This method involves installing a one-way valve in the path of air flowing from the pump to the mask, closing this valve when the wearer exhales, and
The pump continues to rotate but draws in very little or virtually no air.

In a preferred embodiment, the outlet valve is such that the pressure within the mask is approximately 60Q, such as that specified for breathing apparatus using bottled gas in Chapter 2 of British Standard 4667.
It is set to open above the z-skull (this pressure is much lower than the operating pressure normally required for a power assisted positive pressure breathing machine). Additionally, in this preferred embodiment, the pump is arranged to stop or substantially stop downstream of the pump and upstream of the mouth valve.

The pump can deliver a maximum of about 2001/min and a minimum of 200 l/min depending on demand and the flow resistance presented by the filter.
It is arbitrarily arranged to give a flow rate of /min.

It has been discovered that by using such a system, the ratio of the filter effectively used to the filtered air then being breathed is increased from 1/3 to at least 80%.

Mask (facepiece) is a partial or full face mask or 1i on the head! It may be either a suitable sealed helmet or a 7-door, which are connected by flexible hoses to the pump and filter means.

Advantageously, the filter consists of one or more cartridges (metal containers) containing the filtrate material and is removably attached to the inlet to these RI pumps. .

The pump is powered by a battery-powered motor! Preferably, the breathing apparatus comprises seven driven fans, thereby making the breathing apparatus portable.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The respiratory apparatus of the present invention shown in FIGS. 1 and 2 is a mask 1.
(which is shown as a full-face mask that covers the wearer's eyes, nose, and mouth) and is sealed peripherally to the wearer's head. Mask 1 is
- shoulder outlet with tract outlet valve (or exhalation valve) 2;
Air exits the mask through the valve 2 mentioned above. The mask 1 further covers an inlet 3, which is connected to the means 5 by a flexible hose 4. The hand 1ii5 is held on the wearer's backrest by the illustrated clap, retainer, or alternatively in front of the wearer by a similar retainer.

The means 5 have an outer body in which the pump means consisting of a fan (for example a centrifugal fan) and a motor operated by a battery are placed. The outer body has an outlet 8t4 forming an outlet of the fan, to which the hose 4 is connected, and the outer body further has one or multiple (three in the illustration) inlets connected to the inlet of the fan. has 0. Each inlet lO has a filtration cartridge (-! or metal container) 11
11 has a filtration material for particles and/or a filtration material for gas or paper. Such a cartridge 11 is attached to one or several of the inlets 10, and the inlets that are not used are closed by plugs [2].

As can be seen from the foregoing, increasing the number of installed cartridges 11 increases the efficiency of filtration by reducing the flow rate of air passing through each cartridge, thereby increasing the resistance to air flow through the respirator. reduced. The motor is connected to the battery 6 by a cable 27, as shown in the figure.
and another means having an open/close switch 7, which controls the power supplied to the switch 7a1 motor. Alternatively, the battery and the switch can be placed in the means 5.

As shown in FIG. 2, the outlet valve 2. is springed into the closed position, for example by a helical spring 14, and the valve 2 opens only when the air in the mask reaches a predetermined pressure above atmospheric pressure, allowing air to flow out of the mask. For example, valve 2 opens when the pressure within the mask is approximately 600/# skull.

A one-way population valve 13 is inserted into the inlet 3 of the mask and opens to allow air to flow from the pump into the mask. Valve 1
3 may for example be a flap valve, which is not triggered and the valve 13 closes as soon as the pressure downstream of it in the mask exceeds the pressure upstream of it in the hose 4.

The displacement of the pump means 5 is such that during exhalation of the wearer, the pressure within the mask is built up to the point where it exceeds the pressure in the hose 4, at which point the valve 13 closes.

As soon as the valve [3 is closed, a pressure is built up in the hose 4 which causes the pump means 5 (which continues to operate) to draw air into the breathing apparatus and thus the filter. Stop or actually stop breathing air. Additionally, during exhalation, square 2 opens to allow exhaled air to flow out of the mask.・This happens almost at the same time as the closure of square 13.

Near the end of exhalation, the pressure inside the mask decreases and valve 2 closes.
is closed and the pressure drops below the pressure in hose 4,
3 is opened and at this point the pump is again enabled i/
Il: Begins to move and sends the air needed for inspiration to the mask.

Thus, by suitably determining the operating pressure of the outlet valve 2 relative to the expiratory pressure and the characteristics of the pump, it is possible to vary the effective operation of the pump according to the breathing cycle of the wearer. This reduces the amount of air that is drawn into the mask through the filter but is not breathed, so that at least 80% of the filter air can be used to pass through the breathable air.

FIG. 5 shows the pump means 5, inlet and Yamaguchi valves 13 and 2 currently considered optimal for the wearer's breathing cycle.
The work JII is shown in explanatory diagram B9. As shown, valve 13
and 2v'i during the respiratory cycle open and close at the same points, but these points can be moved relative to each other.

As shown in FIG. 2, the mask has an internal mask 15, [
5 completely surrounds the wearer's nose and mouth and has one or more one-way artificial valves 16. These valves 16 are, for example, unfired flap valves, which prevent exhaled air from flowing into the entire mask and thus serve to limit the exhaled air that can be rebreathed. The inner mask seals well against the wearer's face. Therefore, leakage from the ends is prevented, the squares 13 can be played, and each square 16 fulfills its function.

Figures 3 and g4 show valves 2, 13 and pump means 5.
A preferred embodiment is shown below. As shown in FIG. 3, the valve 13 is a flap valve, having a flexible disc 20tl, seated on a seat 21 surrounding an opening in the inlet 30 passageway to the mask;
When the pressure in the mask becomes lower than the pressure in the hose 4, the seat 21 is moved away, allowing air to flow into the mask. The outlet valve 2 is a flap valve with a rigid disc of 22tN
L, 22 sits on a floating stone surrounding the exit opening, and the spiral f
l14 into the closed position, 14 is the disk 2
2 and the part of the outer body around the outlet. The air is
It exits from the valve through the opening 24, which communicates with the opening inside the seat.

The pump means 5 shown in FIG. 4 has a motor 26 connected to a battery by a cable 27, 2b connected to the shaft of a centrifugal fan 4, the outlet of which is connected to the outlet 8 of the outer body. . The inlet of the fan is shown connected to three outlets 10 in the body, each of which is threaded to receive a filter cartridge 11. One, two or three cartridges can be used;
Unused populations are closed by plugs 12.

In the second embodiment of the breathing apparatus described above, the Yamaguchi valve 2 is set to open when the pressure within the mask reaches approximately 61) O/e skull. The large mouth valve 13 closes as soon as the pressure inside the mask exceeds the pressure in the hose 4, which is typically when the pressure inside the mask is about 600/”. 20
Flow rate f until 01/min! :G6 set to give and serve
When the valve 13 is closed, the pressure in the hose 4 is approximately 600/! At this pressure, which is slightly lower than the pressure inside the mask, the fan continues to spin but produces no or virtually no airflow.
In particular, conditions are placed such that no air is drawn into the outer body and through the filter cartridge.

The pressures and flow rates mentioned above are merely for illustration purposes and these may be increased or decreased depending on the current demands on the mask.

Additionally, while the foregoing has described a respirator having a full face mask, the present invention also describes a respirator having a partial face mask and a hood or helmet that is tightly sealed to the wearer's head. The same applies to the facepiece 7″
L attends. Additionally, although in the above description the valve 13 is placed directly into the mask, this valve could be placed at any convenient point between the fan and the mask. Furthermore, although the breathing apparatus described above is particularly suitable for gas and paper filtration, it is of course equally applicable to dust or particulate filtration; can increase the efficiency of use.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a respirator according to one embodiment of the present invention in a reused state, Fig. 2 is an explanatory diagram of the respirator of Fig. 1, and Figs. 3 and 4 are views of a mask, respectively. FIG. 5 is a perspective view of the vent, outlet and pumping means; FIG. l...face mask, 2...outlet valve, 3...inlet,
4... Hose, 5... Pump means, ll... Filter cartridge, 13... Inlet valve. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] 1. A mask (1) having an inlet (3) and an outlet and covering at least the mouth of the wearer, and a mask (1) placed in the outlet so as to create a predetermined pressure difference between the wearer's exhalation. a one-way valve (2) which operates to allow air to flow out of the mask when air is generated; a pump (5) connected to said inlet (3) for delivering air to the mask; In a breathing apparatus assisted by a power filter ([1) and a metal filter]: a second passage is provided in the passage of air flowing from the pump to the mask;
ff (13), this valve (L3) is arranged to close when the downstream full pressure of the valve becomes equal to or higher than the upstream pressure during exhalation of the wearer, and the pump is operated @
A breathing apparatus characterized in that it is placed in a state in which it continues to breathe, but draws in very little or substantially no air. 2. Respiratory device according to claim 1, characterized in that said second one-way valve (13) is located in the inlet (3) of the mask. 3. Breathing device according to claim 1, characterized in that the second one-way valve (L3) is located intermediate the outlet of the pump (5) and the master volume (3). 4. The second one-way valve (13) I/'i consists of a non-strapped flap valve, which closes as soon as the downstream pressure exceeds its upstream pressure. The breathing apparatus according to any one of Items 1, 2, and 3. 5. The respiratory apparatus according to claim 1, wherein the first one-way valve (2) fi comprises a flap valve t-t16fm that is flipped into a closed position. 6. The breathing apparatus according to claim 1, wherein the pump (5) is connected to the mask by a flexible hose (4) to provide a better hold on the wearer. 7. The respiratory apparatus according to claim 1, characterized in that the mask (1) is adapted to cover the wearer's mouth and nose. 8. Respiratory device according to claim 1, characterized in that the mask (1) covers the wearer's mouth, nose and eyes. 9. a mask (1) having an inlet (3) and an outlet and covering at least the mouth of the wearer; a one-way valve (2) placed in said outlet and operative to allow air to flow out of the mask; (1), a pump (5) connected to the inlet (3), and a filter (1) for controlling all the air sent to the mask by the pump (5). In a method of operating a power-assisted breathing apparatus: a second one-way valve (13) is provided in the path of air flowing from said pump (5) to the mask, said second one-way valve (13) being provided during exhalation of the wearer; A method of operating a breathing apparatus, characterized in that the valve is closed and the pump (5) is left in a state where it continues to operate but sucks in very little air or essentially no air.