RESPIRATOR

Abstract: A respirator having a cup-like body (7) associated with an air inlet (8) and an air outlet (9) and having a peripheral sealing element (2) shaped for location across the nose and around the mouth of a wearer wherein the sealing element (2) is located in position by a clamping element (3) which is releasably secured to the cup-like body (7).

Description: RESPIRATOR The present invention relates to a respirator and more particularly (but not exclusively) to those respirators known as half-mask respirators which are intended to cover only the nose and mouth of a wearer. Most conventional half-mask respirators are moulded from natural rubber or other similar material (synthetic rubber, silicone rubber, PVC etc.). With this type of mask the face seal is effected by the part of the mask in contact with the face. To achieve this it is usual to have a reflex edge in which region the moulding is thinner and more flexible. Other masks use an inflatable seal against the face and this may be combined with a ' rubber mask or a rigid plastic mask. With the conventional masks, it may not be possible to replace the seal easily once it has lost its effectiveness due to repeated use of the mas , which must therefore be discarded. It is an object of the present invention to obviate or mitigate the above disadvantage. 'According to the present invention there is provided a respirator having a cup-like body associated with an air inlet and an air outlet and having a peripheral sealing element shaped for location across the nose and around the mouth of a wearer, wherein the sealing element is located in position by a clamping element which is releasably secured on the cup-like body. Preferbly, the cup-like body and clamping element each have flanges which come into face-to-face clamping relationship when the clamping element is mounted on the body, and the seal has a skirt or the like which is clamped between these flanges to retain the seal in position. The invention will be further described by way of example only with reference to the accompanying drawings in which: Fig. 1 is an exploded perspective view of one embodiment of half-mask respirator in accordance with the invention; " Fig. 2 is an exploded, part-sectional side view of the mask shown in Fig. 1, but omitting details of the harness; and Fig. 3 is a side view of the assembled mask. The illustrated half-mask respirator comprises a cup-like body 1 shaped for location over the nose and mouth of a user, a cushion-like face seal 2 for location on the cup 1, an outer clamping element 3, a standard filter cartridge 4, an inhalation valve 18 (not shown in Fig. 1, but clearly illustrated in Fig. 2), exhalation valves 5 (only one shown), and harness straps 6. Cup 1 is a rigid plastic moulding formed as a cup-shaped body 7 having an aperture 8 in a flat frontal face thereof and two apertures 9 in a flat basal face thereof. Aperture 8 is extended inwardly by an internally screw-threaded tubular projection 8a in which an air inlet valve 18 (see Fig. 2) is located. Projecting . laterally from the rim of the body 7 is an integral flange 10. Clamping element 3 is also a rigid plastics moulding and comprises a wall 11 with a stand-off guard portion 12. More particularly, wall 11 is shaped to be a close fit around the body 7 save that the guard portion 12 will stand slightly clear of the flat basal face of body 7 to allow the exhaust valves 5 to be positioned in apertures 9. The basal surface of guard portion 12 is slotted so as to allow- passage ^ of air from valves 5. Also provided on clamping element 3 is a flange 13 integral with the wall 11. Finally, stud-like 5 projections 14 are provided on wall 11. Complimentary snap-fit formations (not shown) are provided on the wall 11 of clamping element 3 and on the body 7 of cup 1 whereby clamping element 3 is a snap fit on cup 1. The snap fit formations may 10 take a number of forms. For example, the cup-like body 7 may have a contiuous or discontinuous undercut in which a complimentary projection on the inner surface of wall 11 locates. With element 3 snap-fitted on cup 1, the flanges 10 and 13 are in 15 face-to-face clamping relation. Face seal 2 is of the form illustrated in Fig. 1. More particularly the ring is shaped for location on, and around, the flange 10 of cup ' 1. Seal 2 is formed of a core ring of soft foam-rubber 15 clad 20 with flexible PVC 16, such that seal 2 is of cushion-like construction. This PVC cladding 16 has a skirt 17 (the purpose of which will be described) provided around the inner periphery of the ring-like face seal body and extending inwardly thereof. The 25 width of skirt 17 is substantially the same as that of flanges 10 and 13. Assembly of the half-mask is as follows, it being assumed that inlet valve 18 and outlet valves 5 have been located in position. 30 Firstly, face-seal 2 is mounted on the cup 1 by manipulating the skirt 17 of seal 2 such that it overlies flange 10 of cup-like body 1. With the seal 2 so mounted on cup 1, a substantial part of the seal's ring like body is located on the side of 35 flange 10 remote from the cup-shaped body 7. Next, clamping element 3 is snap-fitted onto cup 1 thus ensuring that skirt 17 is securely clamped between flanges 10 and 13 thereby fixing seal 2 in position. With clamping element 3 located in position, guard portion 12 serves to protect valves 5 whilst allowing passage of air from the valves 5. Assembly is completed by screwing cartridge 4 into projection 8a and finally attaching harness straps 6 to studs 14. The assembled mask is of cou_.se worn with the seal 2 locating over the bridge of the nose and around the mouth of a wearer, the mask being supported in position by the harness straps 6 locating around the back of the wearers head. When the mask is worn, these harness straps 6 'pull' the clamping element 3 towards the face of the wearer thus enhancing the clamping action. During inhalation, air is drawn through (and thus filtered by) the cartridge 4. Exhaled air is exhausted via the outlet valves ' 5. It is inevitable that seal 2 will lose its effectiveness after repeated usage of the mask. With the illustrated mask construction, the seal may be replaced quickly and easily by releasing and removing clamping element 3 from cup 1 (after removal of cartidge 4 if necessary), removing the old seal, fitting a new one, and re-assembling the mask. Consequently there is no need to dispose of the mask once the seal loses its effectiveness. The illustrated mask has a cushion-like seal. Other types of seal could however be used, e.g. inflatable seals or reflex-edge seals..

Claims: CLAIMS: 1. A respirator having a cup-like body associated with an air inlet and an air outlet and having a peripheral sealing element shaped for location across the nose and around the mouth of a wearer wherein the sealing element is located in position by a clamping element which is releasably secured to the cup-like body. 2. A respirator as claimed in claim 1 wherein the cup like body has a cup for location over the mouth and across the nose of a wearer and a first flange extending around the periphery of the cup said clamping element locates around the cup and has a second flange, and a portion of -said sealing element is clamped between said first and second flanges. 3. A respirator as claimed in claim 2 wherein the cup has a front face having an aperture therein, said aperture being extended by an inwardly directed tubular projection forming the air inlet and in which is provided an inhalation valve. 4. A respirator as claimed in claim 3 wherein a filter cartridge is supported in said tubular projection. 5. A respirator as claimed in claim 2 wherein the cup has a flat basal surface having at least one aperture in which is located an exhalation valve. 6. A respirator as claimed in claim 5 wherein the clamping element has a guard portion for protecting the exhalation valve. 7. A respirator as claimed in any one of claims 1 to 6 wherein the clamping element and the cup like body have complimentary snap fit formations for effecting said releasable securement. 8. A respirator as claimed in any one of claims 1 to . 7 wherein the sealing element comprising a ring of soft foam rubber clad with a flexible plastics material. 9. A respirator as claimed in claim 8 wherein the flexible plastics material is PVC. 10. A respirator as claimed in any one of claims 1 to 9 wherein the clamping element is provided with studs for the securement thereto of a harness for location around the back of the head of a wearer of the mask.

Inventors: FEENEY JOHN ROBERT, FEENEY, JOHN, ROBERT
Applicants: PROTECTOR SAFETY LTD, PROTECTOR SAFETY LIMITED
Application year: 1986
Main classification: A62B18
IPC codes: A62B18