FILTER CONTAINER FOR CONNECTION TO A BREATHING PROTECTION MASK

Abstract: The invention concerns a filter container for an absorption filter (8) and a particle filter (7), said container being adapted to be connected to a protective mask. The filter container is characterised in that it comprises a cup-shaped casing (1) which has in its bottom (2) an inlet (3) for inhalation air, and a cover (4) closing said casing (1), said cover having an outlet (5) for inhalation air and being connectible to the protective mask, said particle filter (7) being arranged at the bottom (2) of the cup-shaped casing (1), and said absorption filter (8) being arranged between the particle filter and the cover (4) closing the casing; that the particle filter (7) is sealed to the casing (1) by means of glue (9) applied to the inner side of the casing; that the portion (14) of the cup-shaped casing (1) containing the particle filter (7) is essentially cylindrical and has a diameter smaller than the re­ maining cylindrical casing portion (13) containing the absorption filter; that the bottom (2) of the casing (1) and the cover (4) are slightly conically bulging outwardly towards the air inlet (3) and the air outlet (5), respectively; and that closely lying, radially extending stiffening ribs (15, 16) are arranged on the slightly conical portions of the bottom (2) and the cover (4), respectively, and have their tops (17) facing inwardly towards the container lying in radial planes.

Description: The present invention relates to a filter container for an absorption filter and a particle filter, said container being adapted to be directly or indirectly connected to a breathing protection mask, comprising a cup-shaped casing which has in its bottom an intake for inhalation air, and a cover closing said casing, said cover having an outtake for inhalation air and being connectible to the breathing protection mask, said particle filter being arranged at the bottom of the cup-shaped casing and said absorption filter being arranged between the particle filter and the cover closing the casing. FR 1 464 075 is directed to a filter container according to the preamble of claim 1. There are only ribs at the outtake and they are of an unknown design. Further, the ribs do not contact the absorption filter. FR 845 722 shows a filter unit including an absorbtion filter enclosed by the cylindrical casing and two planar and cylindrical perforated discs. A spring device urges one of the discs in contact with the absorbtion filter material (the coal powder), thus compacting this material. Neither the bottom nor the top of the casing is equipped with ribs. The filter container according to the present invention is characterized in that the particle filter is sealed to the casing by means of glue applied to the inner side of the casing; that the portion of the cup-shaped casing containing the particle filter is essentially cylindrical and has a diameter smaller than the remaining cylindrical casing portion containing the absorption filter; that the bottom of the casing and the cover are slightly conically bulging outwardly towards the air intake and the air outtake, respectively; and that closely lying, radially extending stiffening ribs are arranged on the slightly conical portions of the bottom and the cover, respectively, the stiffening ribs are circumferentially arranged alternately in longer and shorter radial lengths on said bottom of the casing and said cover and have their tops facing inwardly towards the container lying in radial planes contacting respectively filter. One of the advantages afforded by the present invention is that the tightness of the particle filter can be tested during production, before the casing is equipped with the absorption filter, whereby the production cost can be kept low. The invention will be described in more detail below, reference being had to the accompanying drawings which illustrate an embodiment, chosen by way of example, of the filter container according to the invention. In the drawings Fig. 1 is a vertical section of the casing, the left hand side showing the two filters; Fig. 2 shows the casing as seen from above; Figs. 3 and 4 show parts of Fig. 1 on a far larger scale; Fig. 5 is a vertical section of the cover; Fig. 6 shows the cover as seen from below; Figs. 7 and 8 show parts of Fig. 5 on a far larger scale; Fig. 9 shows, on a far larger scale, a section of Fig. 6 along the arrows indicated therein; and Fig. 10 shows the components according to Figs. 1 and 5 in the assembled state, partly in section. The filter container comprises the cup-shaped casing 1, the bottom 2 of which is formed with an air intake 3, and a cover 4 closing the casing 1 and formed with an air outtake 5. The cover 4 is adapted to be directly or indirectly connected to the breathing protection mask. To this end, the cover 4 either has a tubular, threaded central portion 6 for direct connection with the protective mask, or is formed such that it can be connected to the mask via an adapter. As will appear from Fig. 1, the particle filter 7 is provided at the bottom 2 of the cup-shaped casing 1, the absorption filter 8 being mounted between the particle filter 7 and the cover 4 closing the casing. In the embodiment illustrated, the particle filter 7 consists of a folded paper-like material, while the absorption filter 8 may be a carbon filter. The particle filter 7 is tightly connected to the casing 1 by applying a glue 9 around the inner side of the casing. The glue 9 is applied to the upper edge of the particle filter 7, where the casing 1 has an annular recess 10 to accomodate the glue 9. Above the annular recess 10, the casing 1 has an annular shoulder 11 against which a grid 12 confining the absorption filter 8 is adapted to abut. The absorption filter 8 is adapted, in the closed condition of the casing 1, to urge the grid 12 into firm engagement with the annular shoulder 11. When the cover 4 has been applied to the casing 1, it thus compresses the powder material of the absorption filter 8, whereupon it is connected with the casing 1 by welding or the like. The casing 1 and the cover 4 preferably are made from thermosetting plastic, the thickness of the plastic material being maintained essentially constant. This means that the casing part 13 containing the absorption filter 8 is wider than the casing part 14 containing the particle filter 7, because of the offset provided by the recess 10 and the shoulder 11. Since the cylindrical portion 14 thus has a diameter which is smaller than that of the portion 13, the assembled filter container will not to any appreciable degree block the field of vision of the person wearing the breathing protection mask. At the air intake 3 in the bottom 2 of the casing 1 and at the air outtake 5 in the cover 4, radially extending stiffening ribs 15, 16 are closely arranged. As will appear from the drawings, the bottom 2 of the casing 1 and the cover 4 are slightly conically bulging outwardly towards the air intake 3 and the air outtake 5, respectively, the tops 17 of the stiffening ribs 15, 16, which are facing inwardly toward the container, lying in radial planes, see Fig. 9. Thin textile filters preferably are mounted on both sides of the absorption filter 8. In Figs. 3, 4, 7 and 8, the components 18, 19, 20 and 21 as illustrated in Figs. 1 and 5 are shown on a larger scale. The invention is not restricted to the embodiment described above and illustrated in the drawings, but may be modified in various ways within the scope of the appended claims.

Claims: A filter container for an absorption filter (8) and a particle filter (7), said container being adapted to be directly or indirectly connected to a breathing protection mask, comprising a cup-shaped casing (1) which has in its bottom (2) an intake (3) for inhalation air and radially extending ribs (15), and a cover (4) closing said casing (1), said cover having an outtake (5) for inhalation air and being connectible to the breathing protection mask and radially extending ribs (16), said particle filter (7) being arranged at the bottom (2) of the cup-shaped casing (1) and said absorption filter (8) being arranged between the particle filter and the cover (4) closing the casing, said bottom (2) of the casing (1) and the cover (4) are slightly conically bulging outwardly towards the air intake (3) and the air outtake (5), respectively, and the ribs (15, 16) are arranged on the slightly conical portions of the bottom (2) and the cover (4), respectively, characterized in that the particle filter (7) consists only of a folded paper-like material and is sealed to the casing (1) by means of glue (9) applied to the inner side of the casing; that the portion (14) of the cup-shaped casing (1) containing the particle filter (7) is essentially cylindrical and has a diameter smaller than the remaining cylindrical casing portion (13) containing the absorption filter; and that the ribs are closely and circumferentially arranged alternately in longer and shorter radial lengths on said bottom (2) of the casing (1) and said cover (4) and have their tops (17) facing inwardly towards the container lying in radial planes, the ribs (15) of the bottom (2) of the casing (1) directly supporting the particle filter (7) in cooperation with an intermediate grid (12) positioned between the particle filter (7) and the absorption filter (8) and is fixed on the casing (1). A filter container as claimed in claim 1, characterized in that the glue (9) around the inner side of the casing (1) is applied to the upper edge of the particle filter (7) where the casing (1) has an annular recess (10) for accommodating the glue (9). A filter container as claimed in claim 2, characterized in that the casing (1) has an annular shoulder (11) above the annular recess (10) adapted to accommodate the glue (9), the grid (12) supporting the absorption filter (8) being adapted to engage said shoulder (11). A filter container as claimed in claim 3, characterized in that, in the closed condition of the casing (1), the absorption filter (8) is adapted to urge the grid (12) into firm engagement with the annular shoulder (11). A filter container as claimed in any one of claims 1 - 4, characterized in that the cover (4) connected with the casing (1) by welding or the like has a tubular, threaded central portion (6) adaped to be connected to the breathing protection mask.

Inventors: SUNDSTROEM, PER OTTO, Sundström, Per Otto
Applicants: SUNDSTROEM SAFETY AB
Application year: 1987
Main classification: A62B23
IPC codes: A62B23, A62B19, A62B7