US 3033200 A
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Description (OCR text may contain errors)
y 1962 F. R. STANLEY 3,033,200
SANITARY MASKS Filed May 8, 1959 lNv ENTOR FREDERIC R. STANLEY BY warm, 4/2 Ji /4* u? m.
7 ATTORNEYS United States Patent 3,033,200 SANITARY MASKS Frederic Reginald Stanley, London, England, assignor of one-half to Martindale Electric Company Limited,
London, England, a company of Great Britain Filed May 8, 1959, Ser. No. 812,061 Claims priority, application Great Britain June 19, 1958 3 Claims. (Cl. 128-146) This invention relates to sanitary masks of the kind comprising a thin supporting member, a layer or pad of filtering medium, for example, cotton'wool or textile gauze supported by said supporting member, and means for holding the mask in position over the mouth and nostrils of the wearer. Such masks are commonly used in an atmosphere which is polluted by dust or other foreign matter.
Masks of the above type as at present used have a supporting member in the form of a plate of substantially rectangular or elliptical shape with the central portion of the upper edge cut away to provide a nose recess, and with a mouth opening below and spaced from the nose recess for the inhalation of filtered air. A strap is attached to the outer sides of the supporting member, which may be passed over the head of the wearer to hold the mask in position.
According to the present invention a supporting member for a sanitary mask of the type referred to is of generally rectangular or elliptical form with at least the central portion of the upper edge formed from a non-metallic fiexibly deformable material.
In one perferred embodiment the supporting member comprises a substantially U-shaped backing plate and an elastic or other flexibly deformable strap extending between the arms thereof, the tension of which strap may be adjustable.
Thus a mask according to the invention comprises a supporting member formed as set forth above and a filter pad attached to one face of the supporting member so that the lower edge of the nose recess is formed from a non-metallic flexibly deformable material.
In a convenient embodiment the elastic or flexibly deformable strap is formed in one with the head strap which holds the mask in position against the wearers face when in use, and may be so arranged that the tension of the part of the strap which forms the elastic portion of the backing plate is adjustable independently of the tension in the remainder of the strap.
Preferably the strap passes through a pair of holes located at each side of the backing plate and in a convenient arrangement the strap passes through a hole located at each side of the backing plate, extends around the adjacent outer edge, and passes through a second hole located at the same side of the backing plate in the same direction as it did through the first, whence it extends away from the backing plate to provide a portion to pass around the head of the wearer to hold the mask in position when in use. This arrangement enables the tension of the head band portion of the strap to be varied without altering the tension in that portion of the strap which forms part of the backing plate.
The two lower corners of the supporting member may be formed with lugs which are bent to hold the filter pad in position in relation to the supporting member.
Sanitary masks according to the invention may be constructed so that the filter pad can be renewed when necessary. In such constructions the supporting member may be made from a stifl but deformable material such as sheet aluminum or even a plastic material or alternatively the filter pad may be permanently attached to the supporting member which may be made of a. cheap mate- 3,033,200 Patented May 8, 1962 rial such as cardboard the whole being disposed of when the filter pad becomes contaminated.
The invention may be performed in various ways but two specific embodiments will now be described by Way of example, and are shown in the accompanying drawings in which FIGURE 1 is a front view of a mask according to the invention.
FIGURE 2 is a fragmentary view of an alternative method of attaching a filter pad to the supporting member, and
FIGURE 3 is a front view of another construction according to the invention.
In the construction shown in FIGURE 1 the supporting member is in the form of a substantially U-shaped backing plate 1 made from a thin sheet of aluminum or like material. A pair of holes 2, 3, are provided towards the upper end of each arm of the U, each hole having a slot 4 associated therewith which extends from the hole 'to the adjacent outer edge of the backing plate 1 for the insertion of an elastic strap 5. The strap 5 is slipped through each of the slots 4 in such a manner that a portion 6 of the strap extends across the upper part of the backing plate 1 passes through the upper hole 2 on each side of the plate in a rearward direction and re-emerges through the second hole 3 whence it forms the portion of the strap which will be referred to herein as the head band 7. The friction of the strap 5 through the two holes 2, 3, on each side of the plate 1 is such that the tension; of the part of the strap which forms the head band 7 may be varied without alfecting the tension of that portion 6 of the strap which extends across the upper part of the Ushaped backing plate.
The filter pad 8, of gauze or cotton-wool, is held in position in relation to the backing plate 1 by means of a pair of rearwardly bent lugs 9 extending from the two lower corners of the plate.
When in position on a wearers face the two upper ends 10 of the U-shaped backing plate which extend beyond the elastic strap 6 bear against the wearers face on either side of the nose so that that portion 11 of the filter pad which is between them is pressed closely against the wearers nostrils. The elastic strap portion 6 maintains the filter pad in position between the wearers nose and upper lip, and being flexible and adjustable, forms a comfortable but firm support for the nose portion 11 of the pad. Filtered air may be drawn through the pad 8 into the wearers mouth through a mouth opening formed in the space between the elastic strap 6 and the lower part of the U-shaped plate 1.
In the construction described the filter pad 8 may be easily replaced when contaminated merely by bending open the lugs 9 at the bottom of the mask replacing the pad with a new one and bending the lugs back into position.
In an alternative construction shown in FIGURE 2 the filter pad is held in position by means of a clip 13 at each lower corner of the backing plate which is merely pushed over the backing plate and the filter pad.
FIGURE 3 shows another construction in which the U-shaped backing plate 20 is made from card-board or like material and the filter pad 21 may be permanently connected to it by staples 22 or the like. In this construction it is impracticable to provide slots between the band retaining holes and the sides of the plate and instead a pair of vertically disposed elongated openings 23, 24 are provided in the arms of the U-shaped backing plate 20 and an elastic strap 25 is passed through the upper opening 23 in each arm of the plate in a rearward direction, is passed around the adjacent outside edge of the plate, and through the lower opening 24 at each side in the same direction as the upper opening 23, whence it extends away from the plate to form the head band 26. This arrangement also creates enough friction between the elase' tic strap and the openings in the plate to allow the portion 27 of the elastic strap extending across the upper part of the backing plate to be adjusted so that its tension is fixed and unaffected by variations in the tension in the head band 26.
What I claim as my invention and desire to secure by Letters Patent is:
1. A sanitary mask comprising a layer of filtering material, supporting means for supporting such layer and having a mouth opening therein consisting of a relatively rigid plate of sheet material having side portions and a joining portion between two adjacent ends of the side portions to define an opening extending from one edge of the plate, a flexibly deformable strap of non-metallic material extending transversely across the opening at a position intermediate in the lengths of the side portions to define, together with the joining portion and parts of said side portions, said mouth opening, and a head strap attached to said side portions by friction means for holding said supporting means upon the face of a wearer with the parts of said side portions extending away from the mouth opening lying on opposite sides of the wearers nose and with the filtering material in position over the mouth and nostrils cf the wearer, said head strap forming with the flexibly deformable strap a single integral strap member, the tension in said head strap and the tension in said flexibly deformable strap being independently adjustable.
2. A sanitary mask as claimed in claim 1 in which said friction means consists of a pair of holes in each side portion wherein said single integral strap member passes in succession through the two holes constituting each pair.
3. A sanitary mask as claimed in claim 1 in which said friction means consists of a pair of holes in each side portion wherein said single integral strap member passes in succession through the two holes constituting each pair, with those portions of said single integral strap member which extend respectively between the two holes of each pair passing around an adjacent edge of the corresponding side portion of the plate.
References (Iited in the file of this patent UNITED STATES PATENTS 1,579,449 Hubbell Apr. 6, 1926 2,318,790 Martindale May 11, 1943 2,378,971 Biederman June 26, 1945 FOREIGN PATENTS 680,339 Great Britain Oct. 1, 1952