EP0267428A1 - Breathing mask - Google Patents

Abstract

A breathing mask (1) is described which contains an exhalation valve (18) arranged in an aperture (6) in the wall (2) of the breathing mask (1). The exhalation valve (18) possesses a thin diaphragm (23) which can be moved towards and away from a sealing seat (28) by the pressure of breath during inhalation and exhalation. In order to produce a reasonably priced breathing mask whose exhalation valve closes reliably, particularly when the air contains dust particles, and which nevertheless has low opening and closing pressure, the diaphragm (23) is provided with a convexity (24). The air can then escape only over part of the circumference of the diaphragm, while the remaining part of the circumference (22) of the diaphragm (23) is connected to a base part (27) in such a manner that the direction of convexity of the convexity (24) is at least partially reversible by the pressure of breath. <IMAGE>

Description

The invention relates to a breathing mask with an exhalation valve arranged in an opening of its wall, which has an outlet opening for breathing air arranged on the circumference of a thin membrane, the membrane being pulled onto a sealing seat when inhaling to close the outlet opening and exhaling to open the Outlet opening is lifted from it.

Such a breathing mask is known from GB-A-2 072 516. The known breathing mask has an exhalation valve that was inserted in the form of a capsule into an opening in its wall. The capsule has two annular flanges, between which the wall is clamped. In one embodiment, the inner opening of the annular flanges is crossed by reinforcing ribs arranged in a star shape, on the center of which a circular membrane sheet is fastened to the outside of the mask. The membrane sheet is made of a thin, flexible material and has a diameter which is slightly larger than the inner diameter of the annular flanges, so that the outer periphery of the membrane sheet still rests on the outwardly facing surface of the outer flange. At the point at which the membrane leaflet rests on the flange, a sealing seat in the form of an annular web is arranged, the cross section of which is tapered in a cutting shape in the direction of the membrane leaflet. When exhaling, the exhaled air presses from the inside onto the membrane sheet in the areas between the reinforcing struts and lifts the circumference of the membrane sheet out of its contact with the sealing seat, so that the exhaled air can escape on the outer periphery of the membrane leaflet. On the other hand, when inhaling, the resulting negative pressure pulls the membrane sheet into contact with the sealing seat.

However, the known exhalation valve is relatively complicated due to the large number of parts that have to be manufactured and assembled separately. Exhalation valves generally have to open at a relatively low breathing pressure, since their arrangement would otherwise be useless. The membrane sheet of the known breathing mask must therefore be made relatively thin and light, in order to actually provide the wearer of the breathing mask with breathing relief. However, this means that there is also a risk of malfunction due to membrane sheets which are not exactly flat. For example, the membrane sheet, which is freely accessible to the outside, can be pinched by some unintentional mishandling, so that it can no longer be pulled flat onto the sealing seat. Furthermore, the membrane sheet lies only on the relatively narrow, cutting-shaped surface of the sealing seat. If a speck of dust has settled on this surface, there remains a gap through which unfiltered air can enter the interior of the breathing mask.

The invention is therefore based on the object of creating a breathing mask with an exhalation valve which opens at a sufficiently low breathing pressure and nevertheless closes safely and reliably when inhaled and which is also inexpensive to manufacture and assemble.

The object is achieved in that the membrane is provided with a curvature and that the outlet opening extends over part of the periphery of the membrane, while the periphery outside the outlet opening is connected to a base part such that the direction of curvature is at least partially reversible by the respiratory pressure.

By reducing the size of the outlet opening, it can be protected much better against the ingress of dust. Nevertheless, the outlet opening can still open with a sufficient cross section, since the opening movement of the outlet opening during exhalation is supported by the curvature of the curvature of the membrane. When inhaling, however, the curvature is drawn into the opening of the wall of the breathing mask, so that a reliable seal is achieved.

Is the curvature according to claim 2 from the outset, d. H. Even in the rest position without breathing pressure, directed inwards, an optimal seal is achieved when inhaled.

However, the curvature can also, if desired, be directed outwards in the rest position.

The configuration according to the invention further makes it possible, according to claim 4, to provide sealing surfaces which abut one another when inhaled.

In this case, according to claim 5, one of the sealing surfaces can be arranged on a bead-like thickening, so that the membrane drawn into the interior of the opening during inhalation abuts the sealing seat without a sharp bend.

The configuration according to claim 6 is particularly expedient, since as a result at least the circumference of the curvature is available as a sealing surface.

Claim 8 describes a further possibility of facilitating the opening movement for the outlet opening during exhalation, without sealing problems occurring during inhalation, an additional sealing surface being able to be accommodated according to Claim 9.

The curvature can be produced in a particularly simple and cost-effective manner by embossing the material of the membrane, which also has the advantage that the curvature can be made to size, so that the seal is further improved.

The exhalation valve of the breathing mask according to the invention is particularly simple and inexpensive to manufacture if the relevant parts are made in one piece from a thin, flexible material.

The additional use of a lip valve according to claim 12 further improves the sealing effect, although it has been found in practical tests that the required legal limit values can also be achieved without the lip valve.

The lip valve is advantageously also made in one piece with the other parts of the exhalation valve.

Through the measure according to claim 14, the opening and closing resistance of the lip valve can be reduced to make breathing easier.

The measure according to claim 15 is the exhalation valve to connect to the breathing mask in a particularly simple and cost-effective manner.

Due to the embodiment according to claim 16, the exhaled air can be collected and directed into the exhalation valve, so that the opening of the valve is facilitated.

The invention can be used for any type of breathing mask. However, it is particularly advantageous if the breathing mask is designed as a half mask with a filtering wall. This type of mask is used in dusty air, whereby the wearing time of the mask is limited (to about eight hours). Then the mask is thrown away. Disposable masks, of course, must be relatively inexpensive. In addition, such a mask should hinder or irritate the wearer as little as possible, even if the wearer has to do physical work. Exhalation valves are a good help, provided that the pressure required to open the exhalation valve is low enough so that most of the exhaled air can escape through the valve and does not have to be pressed through the filter wall. Another problem arises from the moisture in the exhaled air. It must be ensured that as much of the moist air as possible is passed through the valve so that moistening of the filter wall is largely avoided. These requirements are met by the exhalation valve used according to the invention.

• Fig. 1 eine perspektivische Ansicht einer erfindungsgemäßen Atemmaske,
• Fig. 2 den Schnitt II-II aus Fig. 1 für ein erstes Ausführungsbeispiel,
• Fig. 3 eine Darstellung gemäß Fig. 2 beim Ausatmen,
• Fig. 4 eine Seitenansicht der Fig. 2 und 3,
• Fig. 5 den Schnitt V-V durch ein zweites Ausführungsbeispiel in Fig. 1,
• Fig. 6 eine Darstellung gemäß Fig. 5 beim Einatmen, und
• Fig. 7 eine Darstellung der Verbindung Ausatemventil-Atemmaske.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Show it:

• 1 is a perspective view of a breathing mask according to the invention,
• 2 shows the section II-II from FIG. 1 for a first embodiment,
• 3 is an illustration according to FIG. 2 when exhaling,
• 4 is a side view of FIGS. 2 and 3,
• 5 shows the section VV through a second embodiment in FIG. 1,
• 6 is an illustration according to FIG. 5 when inhaled, and
• Fig. 7 is an illustration of the connection exhalation valve-breathing mask.

1 shows a perspective illustration of a breathing mask which is designed as a filtering half mask 1. The half mask 1 has a shape adapted to the face shape of a normal wearer and consists of a filter wall 2 which is permeable to the breathing air but filters out pollutants. The strapping 3 is arranged with tabs 4 on the half mask. An exhalation valve V, which is only schematically indicated in FIG. 1, is arranged in the opening of the filter wall 2 in the region of the mouth of the wearer.

A first exemplary embodiment 5 of this exhalation valve V is shown in more detail in FIG. 2. The exhalation valve 5 is made in one piece from a thin, flexible material, for example from a rubber, a plastic or the like. The exhalation vent 5 extends through an opening 6 which is recessed in the filter wall 2. On the inside 2a of the filter wall 2 facing the carrier, the exhalation valve has an annular flange 7 which is connected to the inside of the filter wall 2, that is to say welded or glued. An intermediate piece 8 adjoins the annular flange 7 and engages over the circumference of the opening 6. The intermediate piece 8 is adjoined by a base part 9, which extends essentially parallel to the flange 7 on the outside 2b of the filter wall 2 and bears against it unconnected. The base part 9 is adjoined by an annular region 10a of a membrane 10 opposite the base part 9. The membrane 10 is provided in the area opposite the opening 6 with a curvature 11 projecting into the opening 6. The curvature 11 is created by embossing the membrane 10, so that an annular, relatively dimensionally stable edge 11a results which separates a cover area 11b from a peripheral area 11c of the curvature 11. The diameter of the annular edge and thus the diameter of the cover area 11b is adapted to the diameter of the opening 6 reduced by the thickness of the intermediate pieces 8, so that the opening 6 is essentially spanned by the cover area 11. The length of the peripheral region 11c is dimensioned such that the cover region 11b essentially closes with the inside 2a of the filter wall 2.

The connection between the annular region 10a of the membrane 10 and the base part 9 is interrupted at a point pointing downwards when the half mask 1 is worn, in order to form an outlet opening 12 (FIG. 4). The outlet opening 12 extends approximately over a quarter of the circumference of the base part and the annular region 10a, while three quarters of this circumference are connected in an airtight manner.

A lip valve 13 connects to the outlet opening 12. The lip valve 13 is formed in one piece with the parts of the exhalation valve 5 described above. The lip valve 13 consists, in a known manner, of a tubular piece of material which has been flattened in such a way that the wall areas of the tubular piece lie flat against one another. The lip valve 13 opens when it is blown in and closes when it is sucked in. The wall thickness of the lip valve 13 can decrease between the outlet opening 12 and an outlet opening 13a of the lip valve 13, so that the required opening and closing pressures can be reduced further.

As shown in FIG. 2, the curvature 11 of the exhalation valve 5 is designed so that the curvature 11 is in the rest position, ie without an inhalation or exhalation pressure, after the valve 5 has been inserted into the opening 6 of the filter wall 2 protrudes into the opening 6. If inhalation is then carried out in the direction of arrow A, the cover region 11b is drawn even further into the opening 6 by the resulting negative pressure, the surface 14 of the peripheral region 11c of the curvature 11 (for reasons of clarity only visible in FIG. 3) against the surface 15 of the intermediate piece 8 forming a sealing seat. Furthermore, the surface 16 of the annular region 10a of the membrane 10 lies against the surface 17 of the base part 9. Relatively large first sealing surfaces 15 and 17 are thus available for the sealing seat, which are equally large second sealing surfaces 14, 16 opposite. If, as a result, the outlet opening 12 is not yet sealed and negative pressure is also present in the area of the lip valve 13, its wall areas are also compressed, so that the exhalation valve does not allow air to pass through in the direction of arrow A when inhaled.

When exhaling in the direction of arrow B in FIG. 3, the exhaled pressure is again in the region 11b of the arch 11 and lifts the membrane 10 from the sealing seat 15, 17. As a result, a certain opening of the outlet opening 12 and the lip valve 13 is already achieved. Depending on the strength of the exhaled pressure, the direction of curvature of the curvature 11 also changes more or less, so that part or all of the circumferential area 11c of the curvature 11 now points away from the opening 6 are connected to each other, a certain dimensional stability is achieved by this jumping, which facilitates the opening and keeping open the outlet opening during exhalation. If, on the other hand, breathing in again in the direction of arrow A in FIG. 2, the curvature 11 jumps inwards again, so that the outlet opening 12 is closed extremely quickly and effectively.

5 shows a further exemplary embodiment 18 of an exhalation valve V, which can be used instead of the exhalation valve 5 in the mask according to FIG. 1. The exhalation valve 18 is in turn made in one piece from a thin, flexible material, such as rubber or plastic or the like. The Exhalation valve 18 has a funnel-shaped collecting space 19 protruding on the inside 2a of the filter wall 2, which is arranged in the region of the mouth and nose of the wearer and collects and directs the exhaled air. The funnel-shaped collecting space 19 lies with an annular flange region 20 on the inside 2a of the filter wall 2. The filter wall 2 is in turn provided with an opening 6 through which an intermediate piece 21 extends. A base part 22 lying opposite the annular flange 20 bears on the outside 2b. A membrane 23 is connected to the base part 22 and has a curvature 24 which essentially encompasses the entire membrane 23. The curvature 24 is arched outward in the rest position, ie without breathing pressure, and forms a dome-shaped collecting space 25. On the side facing downward when the mask is worn, base parts 22 and membrane 23 are not connected and form an outlet opening 26 which is designed and dimensioned analogously to outlet opening 12. A lip valve 27 with its own outlet opening 27a connects to the outlet opening 26 and is designed analogously to the lip valve 13. In the region of the outlet opening 26, a bead-shaped thickening 28 protruding in the direction of the membrane 23 is provided on the base part 22, the surface 28a of which forms the sealing seat for the surface 23a of the membrane 23 opposite the bead-shaped thickening 28.

As FIG. 6 shows, the curvature 24 of the membrane 23 is drawn into the opening 6 when inhaled in the direction of the arrow A by reversing the curvature direction of the curvature 24. As a result, the sealing surface 23a of the membrane 23 lies over the sealing surface 28a of the bead-shaped thickening 28, so that the outlet opening 26 is closed. Due to the resulting negative pressure, the outlet opening 27a of the lip valve 27 is closed at the same time, so that the valve is tight.

When exhaling, not shown, the exhaled air collects in the collecting funnel 19 and is conducted into the dome-shaped collecting space 25. The concentration of the exhalation pressure thereby achieved pushes the membrane 23 outwards, as a result of which the outlet opening 26 and then the lip valve 27 open.

Fig. 7 shows how the exhalation valve 18 is buttoned into the opening 6 of the filter wall 2. An annular constriction 29 is formed by the annular flange 20, the intermediate part 21 and the base part 22, the outer diameter of which corresponds to the inner diameter of the opening 6 in the filter wall 2 and the width of which corresponds to the thickness of the filter wall 2. As a result, the exhalation valve 18 is held securely in the opening 6. When exhaling, the breathing pressure is applied to the wall of the funnel-shaped collecting space 19, which expands and introduces radial tensile forces into the annular flange 20, which tend to pull the intermediate part 21 against the circumference of the opening 6. At the same time, however, the breathing pressure is also present on the inward-facing side of the annular flange 20, so that it is pressed against the inside 2a of the filter wall 2. When inhaled, the arched membrane 23 pulls the base part 22 against the outside 2b of the filter wall 2. In this way, the opening 6 is sealed against the ingress of polluted air. However, the exhalation valve can also be glued on.

7 also shows, it is appropriate that Bend the lip valve 27 in such a way that it essentially follows the contour of the filter wall 2, so that the outlet opening 27a of the lip valve 27 is not directed directly downwards. This prevents the exhaled air from being blown directly onto a possible workplace.

In an analogous manner, the lip valve 13 can also be bent. In addition, it is not absolutely necessary to have the outlet openings 12, 26 and the lip valves 13 and 27 pointing downward. Rather, they can also be directed sideways or upwards, so that the exhaled air can be directed in any desired direction.

The exhalation valves V are manufactured in one piece by dipping a corresponding positive mold into a bath of the material used. In the event that a somewhat larger wall thickness is desired in the area outside the lip valve than the wall thickness in the lip area, a two-stage or multi-stage immersion process has proven to be expedient, in which those parts for which a larger wall thickness is desired are accordingly often in the bath can be immersed. The wall thickness can be adjusted according to the material parameters to the required opening and closing pressure, which results from the required sealing effect. For an exhalation valve according to FIGS. 5 and 6, wall thicknesses of 0.3 mm in the vicinity of the outlet opening of the lip valve have proven themselves, while the other parts had a wall thickness of approximately 0.8 mm.

In a modification of the exemplary embodiments described and drawn, for example, in particular in the exemplary embodiment according to FIGS. 2 and 3, the lip valve can be omitted entirely or its length can be reduced. It is also possible, particularly in the embodiment according to FIGS. 2 and 3, to provide a plurality of outlet openings distributed around the circumference of the membrane instead of a single outlet opening, but the connection area to the base part must be designed in such a way that the direction of curvature can be reversed.

Furthermore, the details shown on the basis of the individual exemplary embodiments can be interchanged, so that, for example, the exhalation valve according to FIGS. 2 and 3 is also designed with a funnel-shaped collecting space and the exemplary embodiment according to FIGS. 5 and 6 without a collecting space. The exhalation valves can still be used in any type of mask where a separate exhalation valve is required or desired.

Claims (17)

1. breathing mask (1), with an exhalation valve (5, 18) arranged in an opening (6) of its wall (2), which has an outlet opening (12, 26) for breathing air arranged on the circumference of a thin membrane (10, 23) , wherein the membrane (10, 23) by inhalation for closing the outlet opening (12, 26) on a sealing seat (15, 17; 28a) is lifted drawn and during exhalation for opening the outlet opening (12, 26) of it, characterized characterized in that the membrane (10, 23) is provided with a curvature (11, 24) and that the outlet opening (12, 26) extends over part of the circumference of the membrane (10, 23), while the circumference outside the Outlet opening (12, 26) is connected to a base part (9, 22) such that the direction of curvature increases due to the breathing pressure is at least partially reversible. 2. Breathing mask according to claim 1, characterized in that the curvature (11) is directed inwards in a rest position. 3. Breathing mask according to claim 1, characterized in that the curvature (23) is directed outwards in a rest position. 4. Breathing mask according to one of claims 1 to 3, characterized in that the sealing seat contains a first, in the vicinity of the opening (6) arranged sealing surface (15, 17; 28a), which has a second, on the membrane (10, 23rd ) arranged sealing surface (14, 16; 23a) is opposite. 5. Breathing mask according to claim 4, characterized in that at least one of the sealing surfaces (28a) on a in the direction of the other sealing surface (23a) projecting, bead-like thickening (28) is arranged. 6. Breathing mask according to one of claims 1 to 5, characterized in that the circumference of the curvature (11, 24) corresponds substantially to the circumference of the opening (6). 7. Breathing mask according to claim 6, characterized in that the second sealing surface (14, 16; 23a) is arranged in the vicinity and / or on the circumference of the curvature (11, 24). 8. Breathing mask according to one of claims 1 to 7, characterized in that the curvature (11) is arranged substantially centrally in the membrane (10) and is smaller than this. 9. Breathing mask according to claim 8, characterized in that the region (10a) of the membrane (10) which extends around the curvature (10) bears against the base part (9) surrounding the opening (6) during inhalation. 10. Breathing mask according to one of claims 1 to 9, characterized in that the curvature (11, 24) is formed as an impression in the membrane (10, 23). 11. Breathing mask according to one of claims 1 to 10, characterized in that the membrane (10, 23) with its curvature (11, 24) and the base part (9, 22) of the exhalation valve (5, 18) in one piece from a thin, flexible material are made. 12. Respiratory mask according to one of claims 1 to 11, characterized in that a lip valve (13, 27) connects to the outlet opening (12, 26). 13. Breathing mask according to claim 12, characterized in that the lip valve (13, 27) is integrally formed with the membrane (10, 23) with its curvature (11, 24) and the base part (9, 22). 14. Breathing mask according to one of claims 12 or 13, characterized in that the lip valve (13, 27) has a reduced wall thickness compared to the remaining wall thickness of the exhalation valve (5, 18). 15. Breathing mask according to one of claims 1 to 14, characterized in that the wall of the exhalation valve (5, 18) extends through the opening (6) in the wall (2) of the breathing mask (1) and contains a constriction which in the opening (6) can be buttoned. 16. Breathing mask according to one of claims 1 to 15, characterized in that a funnel-shaped collecting space (19) is provided for the exhaled air in the interior of the mask (1). 17. A breathing mask according to one of claims 1 to 16, designed as a half mask (1) having a filtering wall (2).

Images