Improvements relating to face masks

Abstract

A filter mask comprises a support frame 10, a filter (22, figure 4a) and a sealing member (25, figure 7) for sealing against the face; the support frame retaining the filter such that ambient air is d

Claims

1. A filter mask comprising a support frame, a filter and a sealing member, the support frame retaining the filter, such that ambient air is drawn through the filter on inhalation by a wearer, wherein the support frame includes a shield that extends over at least part of an outwardly-facing surface of the filter, wherein the shield is separated from the filter, such that air flows, in use, between the shield and the filter.

2. A filter mask as claimed in Claim 1, wherein the support frame comprises a rim and a shield, and the shield is offset from the rim.

3. A filter mask as claimed in Claim 2, wherein the rim extends about and / or over the periphery of the filter, and the shield is offset from both the rim and the filter.

4. A filter mask as claimed in Claim 2 or Claim 3, wherein the rim and the shield are connected together by one or more connection members, which extend between the shield and the rim and fix their relative positions.

5. A filter mask as claimed in any preceding claim, wherein the shield has a shape corresponding to the shape of the filter, such that the surfaces of the filter and the shield are parallel.

6. A filter mask as claimed in any preceding claim, wherein there is a spacing having an average size of 0.1 - 5cm, or of 0.2 - 2.5cm, or of 0.2 -1,5cm, or of 0.3 -1cm between the shield and the filter, measured along a line normal to the surface of the shield.

7. A filter mask as claimed in any preceding claim, wherein the shield has no apertures formed therein, through which the sheet of filtering material is exposed, and forms a continuous barrier.

8. A filter mask as claimed in any preceding claim, wherein one or more ribs are provide that extend across at least part of the surface of the shield that faces the filter, the ribs contacting the filter.

9. A filter mask as claimed in any preceding claim, wherein the surface area of the shield is at least 50%, at least 60%, at least 70%, or at least 80%, or at least 90% or at least 95% of the surface area of the filter.

10. A filter mask as claimed in any preceding claim, wherein the shield extends over less than 100% of the surface area of the filter, such that a portion of the filter is exposed at the periphery of the shield.

11. A filter mask comprising a support frame, a filter and a sealing member, the support frame retaining the filter, such that ambient air is drawn through the filter on inhalation by a wearer, wherein the support frame includes a shield that extends over at least part of an outwardly-facing surface of the filter, and at least part of the periphery of the shield being separated from the support frame, and one or more inlet apertures being defined between the shield and the support frame, through which air is drawn on inhalation by the wearer.

12. A filter mask as claimed in Claim 11, wherein the separation between the periphery of the shield and the support frame is less than 2cm, or less than 1,5cm or less than 1cm.

13. A filter mask as claimed in Claim 11 or Claim 12, wherein the shield forms a continuous barrier and the one or more inlet apertures are arranged around the periphery of the shield.

14. A filter mask as claimed in any one of Claims 11 to 13, wherein the one or more inlet apertures in the nasal region and / or the chin region extend along curved paths from an angled apex in a central region of the mask, outwardly towards the sides of the mask, so as to receive the fingers of the wearer during a fit test, the fingers meeting at the angled apex.

15. A filter mask as claimed in any one of Claims 11 to 14, wherein the filter mask is provided with a cover for the one or more inlet apertures, which enables the apertures to be occluded to perform a fit test.

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