Dust semi-mask

The present invention relates to a dust mask for respiratory protection in dusty air, for single use.

It is known from the Polish application description P 291 212, a dust mask made of filter material in the form of a canopy containing the nasal, cheek and chin parts. It is equipped with an external flexible metal strip in the nasal part and an external headband strap attached to the rim of the cheek part, and at least one exhalation valve consisting of a flexible diaphragm and a two-piece body.

It is also known from U.S. Patent No. 4,977,586, a dust mask fitted with a bellows-shaped exhalation valve made of a uniform, flexible material embedded in an annular base with a smaller diameter in the exhaust opening of the respirator. The bellows have a thin embossed convex shutter at the outlet of the exhaust opening, closing the opening of the opening, moved by the pressure of inhaled and exhaled air. The walls of the bellows, connecting the diaphragm with the base, form two annular layers joined together on parts of the outer perimeter. The unconnected part of this circumference forms an outlet ending in the shape of a duck's beak. When breathing in, the shutter adheres to the edges of the nest, while when breathing out, it deflects in the opposite direction, revealing the outlet leading to the mouth. The flexible walls of the mouth when exhaling deviate from each other, while when inhaling they stick to each other closing the mouth. This type of exhaust valve is not suitable for use in half-masks made of easily deformable filter material due to the danger of valve deformation during storage, installation and use of the half mask.

The half mask according to the invention, in the form of a filter material canopy, comprising a nasal, cheek and chin portion, provided with an external flexible metal strip in the nasal portion and an external flexible headband attached to the periphery of the cheek portion, and at least one exhalation valve consisting of a two-piece body with with a flexible diaphragm closing the valve's opening when breathing in, it is characterized by that the diaphragm is a flexible bellows embedded in a smaller diameter circumference, from the side of the centrally located inlet, between the two-piece body and the valve seat made in the canopy, with at least two outlet holes on the circumference of the larger diameter.

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The two-part body is preferably made of a locking ring and a base with the shape of a cylindrical sleeve with a flange, which has a projection on the lateral surfaces limiting the displacement of the locking ring.

The use of exhaust valves with flexible bellows in a half-mask according to the invention allows to reduce exhalation effort, especially in dusty air.

The subject of the invention is shown in the embodiment in the drawing, in which Fig. 1 is a side view of the half mask, and Fig. 2 is the attachment of a flexible bellows in the half-mask bowl, in the plane of the axial section through the valve.

Example of implementation 1.

The half mask shown in Fig. 1 is made of a filtering material in the form of a bowl 1, which includes a nasal portion A, a buccal portion B and a chin C. An elastic metal strip 6 is attached in the nasal portion A, when tightened, the mask is sealed. On the periphery of the dish 1 in the cheek part B there is a clasp 7 holding the outer elastic headband B which covers the head and ensures that the half-mask is firmly attached to the face. The half mask has two exhalation valves D placed symmetrically on both sides of the ridge 9 in the buccal part B between the nasal part A and chin C. Inhalation is through the filtering material of the canopy 1 and the exhalation through the exhaust valves D. As shown in Fig. 2, in the valve seat made in the bowl 1 there is a two-part exhaust valve body D consisting of a blocking ring 5 and a base 4 in the shape of a cylindrical sleeve with a flange, which has a 4 'projection on the side surfaces of the circumference limiting the slipping of the blocking ring 5. Between the base flange 4 and a blocking ring 5, a flexible bellows 2 for evacuating air are mounted in the seat made in the bowl 1. Bellows 2 are made of two elastic layers connected on the circumference with a larger diameter, one of which, embedded with a smaller diameter circuit in the valve seat made in the bowl 1, is centrally provided with an inlet on the face side, while on the circumference 2 in diameter, two 3.3 'outlet openings are arranged symmetrically.

Example of implementation 2.

The half mask shown in Fig. 1 made of filter material in the form of a bowl 1, which includes a nasal portion A, a buccal portion B and a chin C. An elastic metal strip 6 is attached to the nasal portion A, which when tightened, seals the half mask. On the periphery of the canopy 1, in the cheek part B, there is a fastener 7 holding an external elastic headband 8, which covers the head and ensures that the half-mask is firmly attached to the face. The half mask has an exhalation valve D located in the right buccal part B between the nasal part A and chin C. Inhale is done through the filtering material of the bowl 1 and the exhalation through the exhalation valve D.

As shown in Fig. 2, the valve seat made in the bowl has a two-part exhaust valve body D consisting of a blocking ring 5 and a base 4 having the shape of a cylindrical sleeve with a flange, which has a 4 'projection on the side surfaces of the circumference limiting slipping of the blocking ring 5 . Between the base flange 4 and the locking ring 5, in the valve seat made in the bowl 1, there is a flexible bellows 2 for air discharge. Bellows 2 are made of two elastic layers connected on a larger diameter perimeter, one of which, embedded with a smaller diameter circumference in the valve seat made in the bowl 1, has a centrally made inlet on the face. On the perimeter of the bellows 2 with a larger diameter, two outlet openings 3, 3 'are arranged asymmetrically.

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