Filter frame

1. A disc filter frame comprising a base member and a lever, said base member including, adjacent a first end thereof, a breathing aperture and a connection arrangement configured to connect to a respiratory device, said breathing aperture and connection arrangement being aligned so as to define an airflow channel therebetween; said lever being hingedly connected by a hinge mechanism at its proximal end to said base member at said first end and including a sealing member shaped and configured to cover said breathing aperture, the lever being biased in a first position in which a gap is defined between said sealing member and said breathing aperture, and selectively movable to a second position in which said sealing member seals said breathing aperture; a distal end of said lever being located and spaced apart from a second, opposing end of said base member and configured to be manually pressed to move said sealing member from said first position to said second position;

wherein said hinge mechanism comprises at least one foot formed from a downwardly extending generally ‘L’-shaped protrusion, said base member having, located proximal said first end thereof, at least one aperture corresponding to said at least one foot, the base of said generally ‘L’-shaped protrusion being larger in at least one dimension than said corresponding aperture.

2. A filter frame according to claim 1 , wherein said filter frame further comprises a biasing member between said base member and said lever which is arranged and configured to exert a force between said base member and said lever and bias said lever in said first position.

3. A filter frame according to claim 2 , wherein said biasing member comprises an elastically deformable tab located between said base member and said lever, adjacent said distal end of said lever.

4. A filter frame according to claim 3 , wherein said tab is connected to, and extends at an angle from, said lever toward said base member.

5. A filter frame according to claim 1 , wherein said sealing member further comprises a layer of sealant material on a surface facing said breathing aperture, said layer of sealant material being shaped and configured to completely cover said breathing aperture when said lever is in said second position.

6. A filter frame according to claim 1 , wherein said lever is configured to be moveable to said second position from said first position by a squeezing action by a user's finger and thumb, wherein said base member is pushed toward said lever and said lever is simultaneously pushed toward said base member.

7. A filter frame according to claim 1 , wherein said base member and said lever are constructed from rigid plastic material.

8. A filter frame according to claim 1 , wherein said connection arrangement comprises a screw thread mechanism.

9. A filter frame according to claim 1 , wherein said breathing aperture is defined by a breathing tube comprising a circumferential wall extending around the periphery of said breathing aperture.

10. A filter frame according to claim 1 , wherein said base member defines a recess at said second end, within which said distal end of said lever is held such that a space is defined between said distal end of said lever and the base member to enable said lever to be moved from said first position to said second position.

11. A filter frame according to claim 10 , wherein said recess is defined by a pair of opposing, spaced apart walls extending substantially perpendicularly from said second end of said base member.

12. A filter frame according to claim 11 , wherein one or more stop members is provided within said recess, extending inwardly from a respective one or more walls, and configured to retain said distal end of said lever within said recess.

13. A filter frame according to claim 1 , wherein the base member comprises a frame including cut-out portions around said breathing aperture.

14. A filter frame according to claim 1 , further comprising a scent media which is agitated when said sealing member is in said second position, said scent media being configured to release scent particles into said channel for airflow when agitated.

15. A filter comprising a filter frame according to claim 1 , and a fibrous casing shaped and configured to enclose said filter frame, said casing having an opening shaped and configured to fit around said connection arrangement, such that an airflow path is directed through the fibrous casing on one side of said filter frame, and through an unobstructed opening comprising said breathing aperture on the other side of said filter frame, in use.

16. A kit of parts comprising:

a respiratory mask comprising a head strap and a face mask, said face mask having at least one opening; and

a filter according to claim 15 configured to be connected over said at least one opening, so as to define an air flow path, in use, from said mask through said fibrous casing.

17. A disc filter frame comprising a base member and a lever, said base member including, adjacent a first end thereof, a breathing aperture and a connection arrangement configured to connect to a respiratory device, said breathing aperture and connection arrangement being aligned so as to define an airflow channel therebetween; said lever being hingedly connected by a hinge mechanism at its proximal end to said base member at said first end and including a sealing member shaped and configured to cover said breathing aperture, the lever being biased in a first position in which a gap is defined between said sealing member and said breathing aperture, and selectively movable to a second position in which said sealing member seals said breathing aperture; the distal end of said lever being located and spaced apart from a second, opposing end of said base member and configured to be manually pressed to move said sealing member from said first position to said second position;

wherein said filter frame further comprises a biasing member between said base member and said lever which is arranged and configured to exert a force between said base member and said lever and bias said lever in said first position; and

wherein said biasing member comprises an elastically deformable tab located between said base member and said lever, adjacent said distal end of said lever.

18. A filter frame according to claim 17 , wherein said hinge mechanism comprises at least one foot formed from a downwardly extending generally ‘L’-shaped protrusion, said base member having, located proximal said first end thereof, at least one aperture corresponding to said at least one foot, the base of said generally ‘L’-shaped protrusion being larger in at least one dimension than said corresponding aperture.

19. A filter frame according to claim 17 , wherein said tab is connected to, and extends at an angle from, said lever toward said base member.

20. A filter frame according to claim 17 , wherein said sealing member further comprises a layer of sealant material on a surface facing said breathing aperture, said layer of sealant material being shaped and configured to completely cover said breathing aperture when said lever is in said second position.

21. A filter frame according to claim 17 , wherein said lever is configured to be movable to said second position from said first position by a squeezing action by a user's finger and thumb, wherein said base member is pushed toward said lever and said lever is simultaneously pushed toward said base member.

22. A filter frame according to claim 17 , wherein said base member and said lever are constructed from rigid plastic material.

23. A filter frame according to claim 17 , wherein said connection arrangement comprises a screw thread mechanism.

24. A filter frame according to claim 17 , wherein said breathing aperture is defined by a breathing tube comprising a circumferential wall extending around the periphery of said breathing aperture.

25. A filter frame according to claim 17 , wherein said base member defines a recess at said second end, within which said distal end of said lever is held such that a space is defined between said distal end of said lever and the base member to enable said lever to be moved from said first position to said second position.

26. A filter frame according to claim 25 , wherein said recess is defined by a pair of opposing, spaced apart walls extending substantially perpendicularly from said second end of said base member.

27. A filter frame according to claim 26 , wherein one or more stop members is provided within said recess, extending inwardly from a respective one or more walls, and configured to retain said distal end of said lever within said recess.

28. A filter frame according to claim 17 , wherein the base member comprises a frame including cut-out portions around said breathing aperture.

29. A filter frame according to claim 17 , further comprising a scent media which is agitated when said sealing member is in said second position, said scent media being configured to release scent particles into said channel for airflow when agitated.

30. A filter comprising a filter frame according to claim 17 , and a fibrous casing shaped and configured to enclose said filter frame, said casing having an opening shaped and configured to fit around said connection arrangement, such that an airflow path is directed through the fibrous casing on one side of said filter frame, and through an unobstructed opening comprising the breathing aperture on the other side of said filter frame, in use.

31. A kit of parts comprising:

a respiratory mask comprising a head strap and a face mask, said face mask having at least one opening; and

a filter according to claim 30 configured to be connected over said opening, so as to define an air flow path, in use, from said mask through said fibrous casing.