US 3118445 A
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Description (OCR text may contain errors)
Jan. 21, 1964 J. M. NORMAN 3,118,445
ARRANGEMENT RELATING TO GAS MASKS Filed Dec. 18, 1959 2 Sheets-Sheet 1 INVENTOR l/w, 57M
Jan. 21, 1964 J. M. NORMAN 3,
ARRANGEMENT RELATING TO GAS MASKS Filed Dec. 18, 1959 2 Sheets-Sheet 2 INVENTOR United States Patent 3,118,445 ARRANGEMENT RELATING TO GAS MASKS John Marius Norman, Oslo, Norway, assignor to Forsvarets A.B.C. Direktorat, Oslo, Norway Filed Dec. 18, 1959, Ser. No. 860,420 Claims priority, application Norway Dec. 22, 1958 1 Claim. (Cl. 128141) The invention relates to gas masks of the type comprising a face covering piece provided with a window in front of the eyes and equipped with fastening straps, filters with sockets and expiration valve.
An object of the invention is to provide a gas mask construction which is very simple and cheap to produce and which therefore is well suitable as an escape mask or as a public mask.
A further object of the invention is to provide a gas mask, which in spite of the simple construction, presents a series of advantages compared with previously known types of gas masks. Thus the invention proposes a gas mask made of one single sheet of weldable material, which sheet is provided with a window extending across the front of the mask as well as downward on both sides of the nose. Further it is proposed that the filters for the inhalation air be placed at the cheek part of the mask, one filter on each side and preferably in such a way that they are secured in connection with or adjacent to the joint seams between the gas mask itself and the window secured therein.
The invention also relates to a special arrangement to prevent the forming of dew on the inside of the window, which is achieved by a special nose cup suspended inside the mask itself.
The above, as well as further features of the invention will appear clearly from the description below and the enclosed drawings, showing embodiments of the invention.
FIG. 1 is a perspective view of a mask according to the invention.
FIG. 2 is a section along the line 11-11 in FIG. 1, of one of the filters with socket.
FIG. 3 is a nose cup according to an embodiment of the invention, and
FIG. 4 shows the nose cup mounted in place inside the mask.
The mask according to the example shown comprises a face covering piece 1 of suitably weldable material, as for instance plastic. This piece has a large central aperture, in which is secured a window 2 extending across the central part of the mask, as clearly seen on the drawing. The window 2 has downward extending side portions 2' on both sides of the nose, a tongue 3 of the face covering piece extending upward along the nose.
The window 2 is made of transparent weldable material, preferably in the form of a suitable, clear plastic. Thus the window 2 and the face covering piece 1, 3 can be joined by a welding seam 12 extending around the window. This method substantially simplifies the production of the gas mask.
The face covering piece of the gas mask is produced by punching out sheets of plastic material, which are then welded together underneath and along the central line 4, at the same time as the necessary connection for the expiration valve 5 is arranged.
The filters for the inhalation air are placed one on each side of the mask adjacent to its cheek part. In the example shown each filter has the shape of a substantially rectangular fiat box 6. This box is secured to the mask by means of tightly fitting pockets or casings 9 of elastic and weldable material, so that the rear part 9' of the pockets can be welded directly to the face covering piece 1.
The filters are arranged in the usual way and in the ice example shown they consist of two filter layers 7 and 8, of which preferably the one is absorbent, while the other one is filtering. The top and bottom of the box are perforated to allow flow of inhalation air through the filters.
FIG. 2 further shows how on both sides a flap valve 11 is arranged for the filters in connection with the pockets 9, 9. This flap valve is also made of weldable material, and thus by simple operation it can be welded to the edge of the opening 13 in the rear wall of the pocket. 10 is the welding seam securing the pockets 9, 9 to the face covering piece 1. 12 is the welding seam between the face covering piece and the Window. It will appear that the welding seam 12 between the window and the face covering piece extends parallel with and adjacent to the welding seam 10 securing the filters, and these two welding seams thereby will support each other so that a well stiffened area is achieved on both cheek parts of the mask, providing the filters with a strong support. Thereby the filters will have no tendency to sway in relation to the mask at movement of the head.
A series of advantages are gained by the described construction of gas masks.
Firstly, a mask is obtained which is simple and cheap to produce, as the face covering piece as well as window and pockets for securing the filters are made of materials which can be mutually joined by welding seams. Secondly, the window has been given such a form that several advantages are gained. Continuous window parts around the eyes with a very good view in all directions are thus obtained; At the same time the dimension of the window is so large that the wearer of the gas mask is easily recognizable. Further the downward extending side parts 2' of the window offer the advantage .that without bending the head forward one can look down in a stooping direction. These parts 2' also form favourable membranes, which in practice have proved to contribute substantially to the fact that speech is transferred much more distinctly than with commonly known gas masks.
In spite of its simplicity the construction is strong and will not become floppy. This is caused, firstly by the above mentioned securing of the filters with the welding seams of their fastening pockets extending adjacent to the welding seam between the face covering piece and the window, and secondly, by the fact that when the mask is in use it will have a tendency to bend along the projecting central part 14, which helps stiffening the mask substantially.
The arrangement of the filters on the side of the mask and close to this also offers a series of advantages. Thereby the filters are out of the way as much as possible,
which is not the case with masks where the filter boxes are screwed on or secured in front of the mouth or chin part. The securing is simple as the filters are kept in place by being inserted into the elastic pockets, so that hinges, bayonet locks etc. are entirely unnecessary.
If the mask is to be used for military purposes, one of the filters can be omitted, so that it will not be in the way while shooting with guns.
The dead volume of the mask is small.
It will immediately be understood that the valve arrangement shown in FIG. 2 is meant only as an example of how such a valve can be arranged for these filters. Thus a series of modifications of the valve are possible within the scope of the invention. Neither is it necessary for the filters to have the above mentioned rectangular box form as shown. If desired, they may for instance be round, oval or have the form of a spherical segment or other suitable form.
The invention also relates to a nose cup to be mounted in gas masks, Which cups are of the type which are placed around the wearers mouth and nose, around which parts the cup in a way known per se engages with its upper edge. The purpose of the nose cup is to prevent the penetration of expiration air into the rest of the mask, where it causes formation of dew on the eye glasses or front window.
The commonly known nose cups are formed as parts of the gas mask and are permanent parts of same. The upper edge of the nose cup is then formed with a sponge part or other soft material for close engagement to the face of the wearer. However, as known, the shape of the face varies a great deal for diflerent persons, so that the desired close fit is not always obtained.
According to the invention the nose cup is formed as a separate unit, which by suitable means can be flexibly mounted in adjustable position in the gas mask. At the same time the nose cup may be formed so that its lower part engages against the mask and also acts as a flap valve.
The nose cup according to FIGS. 3 and 4 consists of a U-formed, bent transparent sheet 20, for instance artificial material. Along the upper edge of this main part a more narrow and somewhat inward projecting part 18, also made of transparent artificial material, is secured by welding or glueing. This upper part is, however, quite thin and flexible, while the main part 20 is made of thicker material and is substantially stiff. Along the lower edge of the nose cup there is attached a skirt 22 of soft, flexible material, as for instance rubber.
The rear of the main part 20 of the nose cup is provided with flaps 21. In the centre and above the outside of the nose cup is provided a press button device 17.
In FIG. 4 is shown how the nose cup is mounted in the gas mask 1.
To the nose part 3 is secured a strip 15 of suitable material provided with a series of press button devices 16, intended for co-operation with a press button device 17 on the front of the nose cup. In other words the nose cup can be optionally fastened with the device 17 to the desired corresponding device 16 on the nose part 3. Thereby a possibility of adjustment of the nose cup is obtained, which provides the desired close engagement around the mouth and nose of the wearer when the nose cup has been correctly adjusted in the gas mask.
At the rear the nose cup 20 is mounted in the mask 1 by means of slots or pockets 19, as shown in FIG. 4, into which pockets the flaps 21 project. If desired, instead of such pockets 19 a series of pockets or slots can be arranged one above the other, so that possibilities of adjustment are present also at the rear of the nose cup by varying the height.
If desired the fastening of the rear part of the nose cup of course also can be done by press button devices or in other ways instead of the described flaps and pockets or slots.
When the nose cup 20 has been mounted in place in the gas mask, the skirt 22 owing to its flexibility will engage closely against the inside of the gas mask. How- Cit ever, owing to its flexibility it will also act as a flap valve. During expiration the air pressure will press it close to the inside of the gas mask. During inhalation, on the other hand, the over pressure on the outside of the skirt 22 will lift it a little away from engagement to the mask and thus let inhalation air in from the valves 11.
The upper edge 18 can if desired be made of for instance sponge rubber.
The nose cup can also be arranged in such a way that the described skirt 22 is formed as a closed tube, conmeeting the interior of the nose cup directly with the expiration valve 5. In this case, however, it will be necessary to arrange valves in the nose cup for the inhalation air. Such valves can then with advantage be arranged as simple flaps 24 covering holes 23, as suggested in dotted lines in FIG. 3. Engagement piece 18 is then formed so that it engages against the nose and mouth part of the wearer with a closed circumferential edge. The open rear edge shown in FIG. 3 will then not be interrupted, but the nose cup will get a substantially hopper-shaped appearance with the wide end of the hopper resting with a flexible intermediate layer against the face of the wearer, while the narrow end of the hopper is connected directly to the expiration valve 5. Nylon springs can be used with advantage for the flexible suspension of such a nose cup inside the mask.
It will immediately be understood that the embodiments shown in the drawing and described above are meant only as illustration of the inventive idea that it can be varied in several ways within the scope of the invention.
A gas mask comprising a face covering piece of plastic material, a central aperture with a pair of spaced extensions, a window of clear plastic secured by welding seams to the face piece and covering the aperture and extensions, a plastic pocket disposed on a side of each extension and secured to said face piece by a welding seam immediately adjacent the welding seam between the window and face piece, filter means disposed in each pocket, and intake valve means in said face piece communicating with said filter means to permit the passage of air through the filter means into the interior of the mask and exhaust valve means in said face piece allowing passage of gas from the mask, the pairs of adjacent welding seams forming reinforced areas supporting the pockets and filter means and the window extensions forming membranes enhancing speech communication and visibility.
References Cited in the file of this patent UNITED STATES PATENTS 2,381,568 Booharin Aug. 7, 1945 2,744,524 Whipple May 8, 1956 FOREIGN PATENTS 1,028,887 Germany Apr. 24, 1958