PROTECTIVE RESPIRATOR'S AIR GUIDANCE SYSTEM AND PROTECTIVE RESPIRATOR

Description

[0001] The invention relates to a protective respirator with an air guidance system, the respirator comprising a face sealing section made of a rubber type substance, inhalation and exhalation valves connected to a frame, the frame being connected to the sealing section, and a filter attached to the frame through which the air to be purified is breathed.

[0002] The invention relates further to a method to guide the air in a protective respirator with an air guidance system, the respirator comprising a face sealing section made of a rubber type substance, inhalation and exhalation valves connected to a frame, the frame being connected to the sealing section, and a filter attached on the frame through which the air to be purified is breathed, the method including the steps of guiding the air through the filter, through the inhalation valve into the face sealing section for breathing, and guiding the breathed air through the exhalation valve outside.

[0003] Such a respirator and method are known from EP-A-0 258 508.

[0004] Another respirator is known from FI-B-69757, providing an enclosure between a frame and a face sealing section. A gas mask, particularly suitable for cold temperatures, is known from US-A-2,741,246. The gas mask comprises a heat exchange sheet provided between a face sealing section and an outer layer of the mask.

[0005] Protective respirators have conventionally been used mainly in industrial work and agricultural work in order to protect the user against harmful dust and gases. Protective respirators are being used increasingly in the home as well; e.g. in order to avoid pollen allergy. The following is a description of some alternative solutions concerning the valve arrangement of protective respirators.

[0006] In accordance with FI patent application 833006, the exhalation valve of a filter bridge type of a half mask is located at an angle in the upper part of the mask's visor to enable the exhaled air to exit. In accordance with EP patent application 258508, the exhalation valve and the inhalation valve have been located concentrically in the face section of the respirator's fore part. The exhalation air is conveyed directly into the surrounding air from the face section.

[0007] One of the major problems with protective respirators is the formation of condensated water on the sealing surface of the face section. The excess moisture causes powerful bacterial growth on the surfaces in contact with the skin and thus leads to skin infections and hypersensitiveness. Further, the mask is extremely unhygienic should more than one person take turns in wearing it. The formation of condensated water is caused by the air temperature outside the face section of the device being lower than inside the face section. The warm and moist exhalation air condensates on the surfaces of the face section when the temperature of these surfaces falls below what is referred to as the dewpoint temperature.

[0008] Another significant problem is encountered when breathing in cold inhalation air in sub-zero temperatures. Since breathing through the protective respirator always causes some degree of breathing resistance, the person using the respirator is generally forced to breath in the air using such a breathing technique as will cause the cold air to pass (especially when working reasonably hard) directly into the person's respiratory organs. Person's afflicted by asthma run a definite health risk in such a situation.

[0009] Often, sub-zero temperatures also lead to the formation of ice in the exhalation valve. When this happens, non-filtered air may leak via the exhalation valve in the wrong direction into the face section.

[0010] A common shortcoming in protective respirators is that the exhalation air leaves the respirator too close to the inhalation inlet. This leads to the risk that the carbon dioxide concentration of the air breathed in may rise to an excessive level. High carbon dioxide levels causes headache, fatigue, and even loss of consciousness in extreme cases. According to the authorities, a carbon dioxide concentration limit of ca. 1 % is still safe when breathing in.

[0011] A shortcoming in several currently available masks that reduces work safety and wearing comfort is that the user's spectacles and protective goggles tend to fog up because of the warm and moist exhalation air. This is generally due to the exhalation air having the possibility of being guided unobstructed from the exhalation valve directly onto the user's spectacles or goggles.

[0012] Since the exhalation valve on conventional protective respirators is on the outside of the mask in the immediate vicinity of the surrounding non-filtered air, a leak in the exhalation valve may result in the unfiltered air outside the valve and in its immediate vicinity being admitted in small amounts along with the inhalation air because of the suction produced during the inhalation stage.

[0013] It is the object of the invention to provide a protective respirator and a method to guide the air in a protective respirator which bring about a decisive improvement to the above shortcomings.

[0014] The object is achieved by a protective respirator, mentioned at the outset, in that an enclosure is provided between the frame and the face sealing section, into which the air that passes through the exhalation valve is guided.

[0015] The above object is further solved by the method to guide the air in a protective respirator, mentioned at the outset, wherein the method includes the further step of guiding the air coming from the exhalation valve into an enclosure between the frame and the face sealing section.

[0016] The foremost advantage of the invention may be seen in that the formation of condensated water on the sealing surfaces of the face section is markedly reduced. This is accompanied by the warming up of the inhalation air and the respirator is safe to use even in sub-zero temperatures. Further, the mixing up of exhalation air into the inhalation air is minimised.

[0017] In the arrangements in accordance with the invention, due to the location of the exhalation valve, the air leaked by the exhalation valve is noticeably cleaner than the air surrounding the respirator, because the unclean surrounding air is not in the immediate vicinity of the exhalation valve, the leaked air has, in the main, composed of air that has been filtered once and then exhaled. As an example, air containing particles as impurities is cleaner between the frame and face sealing section than on the outer surface of the mask, because the exhaled air stays around the exhalation valve in between the user's breaths and the pressure of the exhaled air forces unclean air away through the valve opening.

[0018] In the following, the invention is explained in detail with references being made to the appended drawings.

[0019] Figure 1 is an exploded presentation of the protective respirator.

[0020] Figure 2 shows the protective respirator from above and partially as a sectional presentation.

[0021] Figure 3 shows a side view of the protective respirator and partly as a sectional view along the line C-C in fig. 2.

[0022] Figures 4a and 4b show two different implementations of the heat exchange surfaces.

[0023] Figure 5 is an isometric assembly drawing of a respirator in accordance with the invention.

[0024] Fig. 1 is a schematic exploded presentation of a protective respirator in accordance with the invention. The respirator is composed of a lattice section 1 protecting the filter, a filter 2, a frame section 3 made up of supporting ribbing with a hole for the inhalation air, a valve frame 4 onto which the inhalation and exhalation valves are mounted, and a face sealing section 7 that is connected to a valve frame 4 by means of the respirator's mounting straps, these straps not being shown in fig. 1. The top of the respirator's frame section 3 houses an air guidance plate 8.

[0025] Fig. 2 shows the protective respirator as seen from above and partially as a sectional view of it. The mounting straps 9 are indicated by dashed lines in the drawing.

[0026] Fig. 3 shows the assembled mask placed over the user's face: The presentation is a side view partially as a sectional presentation along the line C-C shown in fig. 2. The drawing shows how the warm exhalation air is guided through the exhalation valve 6 through the frame section 3 and into the air enclosure 11 of the face sealing section 7. Due to convectional force, the warm exhalation air rises upward in the air enclosure 11 until it meets the air guidance plate 8. The air guidance plate 8 guides most of the warm air to the rear and up toward the ears of the person wearing the protective respirator. This being the case, a flow of warm air is generated in the air enclosure formed between the protective respirator's frame section and the face sealing section, the said flow of warm air keeping the temperature in the said air enclosure essentially higher than that of the outside air. The number 16 indicates a removable protective visor.

[0027] The warm exhalation air in the air enclosure maintains the temperature of the face sealing section's outside surface above the dewpoint temperature and thereby the formation of condensated water on the inner surfaces of the face sealing section is significantly reduced.

[0028] The warm exhalation air in the air enclosure also warms up the heat exchange surface 12 forming the rear surface of the frame section 3. Heat is transmitted by conduction from the heat exchange surface to the supporting ribbing 13. On being warmed up, the supporting ribbing releases heat into the filtered inhalation air flowing between the ribbing. Thus, the temperature of the inhalation air is not dangerously cold even for persons afflicted by asthma.

[0029] Since the exhalation air rich in carbon dioxide flows in its own air enclosure and exits essentially via the ends of the respirator, there is little chance of it finding its way back to be breathed in once again. This enhances the respirator's operational safety.

[0030] Due to the guiding plate 8 the warm air is prevented from causing fogging up of spectacles or goggles.

[0031] Figs. 4a and 4b shows another possible solution for the structure of the heat exchange surface 12. The ribbing 13 is thus formed that the frame section 3 is essentially of the same thickness at the points of the ribs as it is next to the air transfer channels 10. The said construction facilitates a more efficient exchange of heat because of the greater surface area and more even thickness of the frame section.

[0032] Fig. 5 shows a fastening stud 15 by means of which the lattice section 1 is fastened onto the frame section. The pressure equalising apertures 14 can be executed, for example, into the section of the lattice 1 curving underneath the respirator. When this is done, the said pressure equalising apertures converge with the apertures made into the corresponding parts of the frame section 3 when the respirator is assembled.

Claims

1. A protective respirator with an air guidance system, the respirator comprising

- a face sealing section (7) made of a rubber type substance;

- inhalation and exhalation valves (5, 6) connected to a valve frame (4), the frame (4) being connected to the sealing section (7); and

- a filter (2) attached on a frame section (3) through which the air to be purified is breathed,

characterized by an enclosure (11) between the frame section (3) and the face sealing section (7), into which the air that passes through the exhalation valve (6) is guided.

2. A respirator as claimed in claim 1, characterized in that the top part of the frame section (3) contains an air guidance plate (8) that adapts itself to the contours of the face of the wearer and is oriented essentially from the frame (3, 4) toward the face of the wearer of the respirator.

3. A respirator as claimed in claim 1 or 2, characterized in that the exhalation air is guided such that it warms up a heat exchange surface (12) of the frame section (3) and a heat exchange ribbing (13) thereon, from which the heat is released into the inhalation air.

4. A respirator as claimed in any of claims 1 to 3, characterized in that the exhalation air is guided such that it warms up the outer surface of the sealing section (7) keeping its inner temperature above the dewpoint and thus preventing the formation of condensated water inside the face sealing section (7).

5. A respirator as claimed in claim 3 or 4, characterized in that grooves or cavities following the orientation of the heat exchange ribbing (13) have been formed into the ribbing.

6. The respirator as claimed in claims 3 to 5, characterized in that the exhalation air is guided such that it exits the respirator essentially in the direction of a filter surface with the heat exchange surface (12) of the frame section (3) and the guidance plate (8) guiding the flow of the exhalation air.

7. A respirator claimed in any of the claims 3 to 8, characterized in that the heat exchange surface (12) forming the other wall of the enclosure (11) is connected to heat exchange ribbing (13) forming a contiguous piece.

8. A respirator as claimed in claim 7, characterized in that the heat exchange surface's (12) side facing the enclosure (11) is comprised of longitudinal grooves and/or cavities opening toward the enclosure (11).

9. A respirator as claimed in claim 8, characterized in that pressure equalising apertures (14) have been executed into the frame section (3) and a lattice (1) outside and/or underneath the exhalation valve (6).

10. A respirator as claimed in any of claims 1 to 9, characterized in that a removable protective visor (16) is attached to the frame (3 section).

11. A method to guide the air in a protective respirator with an air guidance system, the respirator comprising

- a face sealing section (7) made of a rubber-like substance;

- inhalation and exhalation valves (5, 6) connected to a valve frame (4), the frame (4) being connected to the sealing section (7); and

- a filter (2) attached on a frame section (3) through which air to be purified is breathed,

the method including the steps of guiding the air through the filter (2), through the inhalation valve (5) into the face sealing section (7) for breathing and guiding the breathed air through the exhalation valve (6) outside, characterized by the further step of guiding the air coming from the exhalation valve (6) into an enclosure (11) between the frame section (3) and the face sealing section (7).

Ansprüche

1. Schutz-Gasmaske mit einem Luftleitsystem, wobei die Gasmaske aufweist:

- einen Gesichtsabdichtungsabschnitt (7), der aus einer kautschukartigen Substanz hergestellt ist;

- ein Inhalations- und ein Exhalationsventil (5, 6), die mit einem Ventilrahmen (4) verbunden sind, wobei der Rahmen (4) mit dem Abdichtungsabschnitt (7) verbunden ist; und

- einen an einem Rahmenabschnitt (3) angebrachten Filter (2), durch den zu reinigende Luft geatmet wird,

gekennzeichnet durch eine Einfassung (11) zwischen dem Rahmenabschnitt (3) und dem Gesichtsabdichtungsabschnitt (7), in die die Luft geleitet wird, die durch das Exhalationsventil (6) strömt.

2. Gasmaske nach Anspruch 1, dadurch gekennzeichnet, daß der obere Teil des Rahmenabschnittes (3) eine Luftleitplatte (8) aufweist, die sich selbst an die Konturen des Gesichtes des Trägers anpaßt und im wesentlichen von dem Rahmen (3, 4) in Richtung auf das Gesicht des Gasmaskenträgers orientiert ist.

3. Gasmaske nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Exhalationsluft derart geleitet wird, daß sie eine Wärmetauscherfläche (12) des Rahmenabschnittes (3) und eine daran vorgesehene Wärmetauscherriffelung (13) erwärmt, von der die Wärme an die Inhalationsluft abgegeben wird.

4. Gasmaske nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß die Exhalationsluft derart geleitet wird, daß sie die äußere Oberfläche des Abdichtungsabschnittes (7) erwärmt, so daß dessen Innentemperatur über dem Taupunkt gehalten und somit die Bildung von Kondenswasser im Inneren des Gesichtsabdichtungsabschnittes (7) verhindert wird.

5. Gasmaske nach Anspruch 3 oder Anspruch 4, dadurch gekennzeichnet, daß Vertiefungen oder Hohlräume, die sich der Orientierung der Wärmetauscherriffelung (13) anpassen, in der Riffelung ausgebildet worden sind.

6. Gasmaske nach einem der Ansprüche 3 bis 5, dadurch gekennzeichnet, daß die Exhalationsluft derart geleitet wird, daß sie aus der Gasmaske im wesentlichen in Richtung einer Filterflächeaustritt, wobei die Wärmetauscherfläche (12) des Rahmenabschnittes (3) und die Leitplatte (8) die Strömung der Exhalationsluft leiten.

7. Gasmaske nach einem der Ansprüche 3 bis 6, dadurch gekennzeichnet, daß die Wärmetauscherfläche (12), die die andere Wand der Einfassung (11) bildet, mit der Wärmetauscherriffelung (13) unter Ausbildung eines zusammenhängenden Stückes verbunden ist.

8. Gasmaske nach Anspruch 7, dadurch gekennzeichnet, daß die Seite der Wärmetauscherfläche (12), die der Einfassung (11) gegenüberliegt, aus länglichen Vertiefungen und/oder Hohlräumen besteht, die sich zur Einfassung (11) hin öffnen.

9. Gasmaske nach Anspruch 8, dadurch gekennzeichnet, daß in dem Rahmenabschnitt (3) Druckausgleichsöffnungen (14) angefertigt worden sind und ein Gitter (1) außerhalb und/oder unterhalb des Exhalationsventils (6).

10. Gasmaske nach einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, daß ein entfernbarer Schutzschirm (16) an dem Rahmenabschnitt (3) angebracht ist.

11. Verfahren zum Leiten der Luft in einer Schutz-Gasmaske mit einem Luftleitsystem, wobei die Gasmaske aufweist:

- einen Gesichtsabdichtungsabschnitt (7), der aus einer kautschukartigen Substanz hergestellt ist;

- ein Inhalations- und ein Exhalationsventil (5, 6), die mit einem Ventilrahmen (4) verbunden sind, wobei der Rahmen (4) mit dem Abdichtungsabschnitt (7) verbunden ist; und

- einen an einem Rahmenabschnitt (3) angebrachten Filter (2), durch den zu reinigende Luft geatmet wird,

wobei das Verfahren die Schritte aufweist, die Luft durch den Filter (2) durch das Inhalationsventil (5) in den Gesichtsabdichtungsabschnitt (7) zur Atmung zu leiten und die geatmete Luft durch das Exhalationsventil (6) nach außen zu leiten, gekennzeichnet durch den weiteren Schritt, die von dem Exhalationsventil (6) kommende Luft in eine Einfassung (11) zwischen dem Rahmenabschnitt (3) und dem Gesichtsabdichtungsabschnitt (7) zu leiten.

Revendications

1. Respirateur de protection avec un système de guidage de l'air, le respirateur comprenant :

- une partie de recouvrement étanche du visage (7) constituée d'une matière de type caoutchouc;

- des vannes d'inspiration et d'expiration (5, 6) reliées à une monture de vanne (4), la monture (4) étant reliée à la partie de recouvrement étanche (7); et

- un filtre (2) fixé sur une partie de monture (3) à travers lequel l'air à purifier est respiré,

caractérisé par une enceinte (11) entre la partie de monture (3) et la partie de recouvrement étanche du visage (7), dans laquelle l'air qui passe à travers la vanne d'expiration (6) est guidé.

2. Respirateur selon la revendication 1, caractérisé en ce que la partie de dessus de la partie de monture (3) contient une plaque de guidage de l'air (8) qui s'adapte aux contours du visage de l'utilisateur et est essentiellement orientée à partir de la monture (3,4) en direction du visage de l'utilisateur du respirateur.

3. Respirateur selon la revendication 1 ou 2, caractérisé en ce que l'air d'expiration est guidé de telle sorte qu'il réchauffe une surface d'échange de chaleur (12) de la partie de monture (3) et des nervures d'échanges de chaleur (13) sur cette dernière, à partir desquelles la chaleur est évacuée dans l'air d'inspiration.

4. Respirateur selon l'une quelconque des revendications 1 à 3, caractérisé en ce que l'air d'expiration est guidé de telle sorte qu'il réchauffe la surface extérieure de la partie de recouvrement (7), maintenant sa température intérieure à une valeur supérieure au point de rosée et évitant ainsi la formation d'eau condensée à l'intérieur de la partie de recouvrement étanche du visage (7).

5. Respirateur selon la revendication 3 ou 4, caractérisé en ce que des rainures ou des cavités suivant l'orientation des rainures d'échange de chaleur (13) sont ménagées dans les nervures.

6. Respirateur selon les revendications 3 à 5, caractérisé en ce que l'air d'expiration est guidé de telle sorte qu'il sorte du respirateur sensiblement dans le sens d'une surface de filtre, la surface d'échange de chaleur (12) de la partie de monture (3) et la plaque de guidage (8) guidant l'écoulement de l'air d'expiration.

7. Respirateur selon l'une quelconque des revendications 3 à 8, caractérisé en ce que la surface d'échange de chaleur (12) constituant l'autre paroi de l'enceinte (11) est reliée aux nervures d'échange de chaleur (13) formant une pièce contigüe.

8. Respirateur selon la revendication 7, caractérisé en ce que le côté (12) de la surface d'échange de chaleur faisant face à l'enceinte (11) est constitué de rainures longitudinales et/ou de cavités s'ouvrant en direction de l'enceinte (11).

9. Respirateur selon la revendication 8, caractérisé en ce que des ouvertures égalisant la pression (14) ont été ménagées dans la partie de monture (3) et un treillis (1) à l'extérieur et/ou au-dessous de la vanne d'expiration (6).

10. Respirateur selon l'une quelconque des revendications 1 à 9, caractérisé en ce qu'une visière de protection amovible (16) est fixée à la partie de monture (3).

11. Procédé pour guider l'air dans un respirateur de protection avec un système de guidage de l'air, le respirateur comprenant

- une partie de recouvrement étanche du visage (7) constituée d'une matière de type caoutchouc;

- des vannes d'aspiration et d'expiration (5,6) reliées à une monture de vanne (4), la monture (4) étant reliée à la partie de recouvrement (7) et

- un filtre (2) fixé sur une partie de monture (3) à travers lequel l'air à purifier est respiré,

le procédé comprenant les étapes consistant à guider l'air à travers le filtre (2), à travers la vanne d'inspiration (5) dans la partie de recouvrement étanche du visage (7) pour respirer et guider l'air respiré à travers l'extérieur de la vanne d'expiration (6), caractérisé par l'étape supplémentaire consistant à guider l'air provenant de la vanne d'expiration (6) dans une enceinte (11) entre la partie de monture (3) et la partie de recouvrement étanche du visage (7).

Drawing