Emergency respirator

Claim 2

A respirator comprising: a disposable filter located within said respirator; user serviceable canister means for receiving and confining said filter, said canister means comprising: an outer generally tubular casing comprising a partially open end and an integral, circumferential flange spaced apart from said open end; and, an inner generally tubular casing for coupling to said outer casing, wherein an inner volume is defined between said inner and outer casings and said filter is received within said inner volume, said inner casing comprising an integral circumferential flange mated with said outer casing flange and an air inlet for admitting air into said inner volume; cover means for defining a plenum adjacent said canister means, said cover means fitted to said canister means, said cover means comprising an elongated, tubular housing having an integral flange coupled to said inner and outer casing flanges; resilient, removable retaining ring means for sealingly locking said inner and outer casings and said cover means together; mouthpiece means in fluid flow communication with said plenum for enabling a user to breathe through said respirator; first valve means for unidirectionally allowing the flow of air from said inner volume into said plenum when a user inhales through said mouthpiece means; and, second valve means for unidirectionally exhausting air from said plenum externally of said respirator when said user exhales through said mouthpiece means.

Claim 3

The respirator as defined in claim 1 wherein said mouthpiece means is secured to said cover means and spaced apart from said canister means.

Claim 4

The respirator as defined in claim 2 wherein said second valve means is disposed in said cover means.

Claim 5

The respirator as defined in claim 1 wherein said cover means comprises a closed end having a plurality of orifices to establish fluid flow communication to said second valve means and an orifice in fluid flow communication with said mouthpiece means.

Claim 6

The respirator as defined in claim 4 wherein said retaining ring means comprises a generally U-shaped cross section for compressively confining said flanges together to maintain said inner and outer casings and said cover means together.

Claim 7

The respirator as defined in claim 1 wherein said inner casing comprises an integral offset portion projecting toward said mouthpiece for establishing an air gap adjacent said filter.

Claim 8

The respirator as defined in claim 1 wherein said outer casing comprises an integral offset portion projecting outwardly from said respirator for establishing an air gap adjacent said filter.

Claim 9

The respirator as defined in claim 1 wherein said first and second valve means each comprises a valve cover comprising: a generally tubular body portion; a peripheral mounting flange integral with said body portion; a plurality of mounting orifices defined in said last mentioned flanges; and, a plurality of air passageways defined in said valve cover(s).

Claim 10

The respirator as defined in claim 8 wherein said cover, casings and valve covers are constructed of metal.

Claim 11

A respirator comprising: a disposable filter located within said respirator; user serviceable canister means for receiving and confining said filter, said canister means comprising: an outer generally tubular casing comprising a partially open end and an integral, circumferential flange spaced apart from said open end; and, an inner generally tubular casing for coupling to said outer casing, wherein an inner volume is defined between said inner and outer casings and said filter is received within said inner volume, said inner casing comprising an integral circumferential flange mated with said outer casing flange and an air inlet for admitting air into said inner volume; cover means for defining a plenum adjacent said canister means, said cover means comprising an integral flange coupled to said inner and outer casing flanges; resilient means for sealingly locking said inner and outer casings and said cover means together; mouthpiece means in fluid flow communication with said plenum for enabling a user to breathe through said respirator; first valve means for unidirectionally allowing the flow of air from said inner volume into said plenum when a user inhales through said mouthpiece means; and, second valve means for unidirectionally exhausting air from said plenum externally of said respirator when said user exhales through said mouthpiece means.

Claim 12

A respirator comprising: a disposable filter located within said respirator; user serviceable canister means for receiving and confining said filter, said canister means comprising: an outer generally tubular casing comprising a partially open end and an integral, circumferential flange spaced apart from said open end; and, an inner generally tubular casing for coupling to said outer casing, wherein an inner volume is defined between said inner and outer casings and said filter is received within said inner volume, said inner casing comprising an integral circumferential flange mated with said outer casing flange and an air inlet for admitting air into said inner volume; cover means for defining a plenum adjacent said canister means, said cover means comprising an integral flange coupled to said inner and outer casing flanges; resilient means for sealingly locking said inner and outer casings and said cover means together; mouthpiece means in fluid flow communication with said plenum for enabling a user to breathe through said respirator; first valve means for unidirectionally allowing the flow of air from said inner volume into said plenum when a user inhales through said mouthpiece means; and, second valve means for unidirectionally exhausting air from said plenum externally of said respirator when said user exhales through said mouthpiece means.

Claim 13

The respirator as defined in claim 10 wherein said mouthpiece means comprises a bushing passing through and affixed to said cover means and a rubber mouth cover secured around said bushing.

Claim 14

The respirator as defined in claim 10 further comprising strap means for flexibly securing said respirator to said user, said strap means secured to said cover means.

Claim 15

The respirator as defined in claim 10 wherein said means for sealingly locking said inner and outer casings and said cover means together comprises snap fit tabs disposed about said integral, circumferential flanges.

Claim 16

The respirator as defined in claim 13 wherein said mouthpiece means comprises a rubber mouth cover secured in fluid flow communication with said respirator by an bushing extending integrally from said cover.

Claim 17

The respirator as defined in claim 14 wherein said cover, casings and valve covers are constructed of plastic.

Claim 18

An emergency smoke mask comprising: a disposable filter located within the smoke mask for filtering air; user serviceable canister means for receiving and confining said filter, said canister means comprising: an outer generally tubular casing comprising a partially open end and an integral, circumferential flange spaced apart from said open end; and, an inner generally tubular casing for coupling to said outer casing, wherein an inner volume is defined between said inner and outer casings and said filter is received within said inner volume, said inner casing comprising an integral circumferential flange mated with said outer casing flange and an air inlet for admitting air into said inner volume; cover means for defining a plenum adjacent said canister means, said cover means fitted to said canister means, said cover means comprising an elongated, tubular housing having an integral flange coupled to said inner and outer casing flanges; resilient means for sealingly locking said inner and outer casings and said cover means together; mouthpiece means secured to said cover means in fluid flow communication with said plenum for enabling a user to breathe; first valve means for unidirectionally allowing the flow of air from said inner volume into said plenum when a user inhales through said mouthpiece means; second valve means for unidirectionally exhausting air from said plenum externally of said respirator when said user exhales through said mouthpiece means; and, strap means for flexibly securing said mask to said user.

Claim 19

An emergency smoke mask comprising: a disposable filter located within the smoke mask for filtering air; user serviceable canister means for receiving and confining said filter, said canister means comprising: an outer generally tubular casing comprising a partially open end and an integral, circumferential flange spaced apart from said open end; and, an inner generally tubular casing for coupling to said outer casing, wherein an inner volume is defined between said inner and outer casings and said filter is received within said inner volume, said inner casing comprising an integral circumferential flange mated with said outer casing flange and an air inlet for admitting air into said inner volume; cover means for defining a plenum adjacent said canister means, said cover means fitted to said canister means, said cover means comprising an elongated, tubular housing having an integral flange coupled to said inner and outer casing flanges; resilient means for sealingly locking said inner and outer casings and said cover means together; mouthpiece means secured to said cover means in fluid flow communication with said plenum for enabling a user to breathe; first valve means for unidirectionally allowing the flow of air from said inner volume into said plenum when a user inhales through said mouthpiece means; second valve means for unidirectionally exhausting air from said plenum externally of said respirator when said user exhales through said mouthpiece means; and, strap means for flexibly securing said mask to said user.