RU2288012C1 - Respirator half mask - Google Patents

Abstract

FIELD: different harmful industries; means of individual protection of the respiratory organs of people in harmful productions.

SUBSTANCE: the invention is pertaining to the means of individual protection of the respiratory organs of the working staff, in particular, to respirator half mask, and may be used in the cartridge respirators for protection against harmful vapors, gases and aerosols in conditions of the harmful productions. The respirator half mask contains the resilient body consisting of the nose part and the carrying part with the pads having holes for mounting the filtering cartridges and the conjugated with the body obturator interfaced a body with the band of obturation. The body contour in the frontal plane in the field of the obturator consists of four conjugating arcs of circumferences, and in the plane perpendicular to the frontal plane - from three conjugating arcs of circumferences. The angle of turn-down of the obturation band end is smoothly varies along the body contour or has the constant value in the chin part. The angle of turn-down of the obturation band end in respect to the frontal plane the half mask is smoothly increasing from the nose bridge up to the nose wings, further it is smoothly diminishing in the field of the nose wings and cheeks, and at the variable angle it is smoothly diminished in the chin part. The holes for fastening the filtering cartridges are made on the pads of the oval form, their centers are arranged on the equal spacing interval from each other on the generatrix of the contour of the body for all the sizes, which is determined according to the length of the generatrix for the first size of the half mask. The invention demonstrates the increased significance of the protective and ergonomic values and improved manufacturability and economic features of the respirator half mask.

EFFECT: the invention ensures the increased significance of the protective and ergonomic values and improved manufacturability and economic features of the respirator half mask.

2 cl, 3 dwg, 3 tbl

Description

The invention relates to personal respiratory protection and can be used in cartridge respirators to protect against harmful vapors, gases and aerosols in hazardous environments.

The half mask is the main component of respirators and consists of a mating body and a seal. The body is designed to isolate the respiratory system from the environment, attach filter cartridges and exhalation valve. The shutter serves to ensure a tight fit of the half mask to the face, taking into account the wide range of anthropometric values. The problem is solved by establishing a size assortment of half masks (usually three sizes) and using elastic materials for their manufacture.

The complex configuration of the obturation strip due to the variety of values of anthropometric values, their combinations within the same race, the presence of people within a small territorial community, belonging to different races, determine the complex designs of half masks of irregular volumetric shapes having one plane of symmetry. The desire to simplify the design of the shutter with insufficient consideration of the values of anthropometric values leads to negative consequences: to increase the pressure of the half masks on the skin of the face, to increase the coefficient of suction of the half mask over the obturation strip, to increase the field of view of the half mask.

Known half mask respirator (certificate. Pol. Mod. RU No. 14133, IPC ⁶ A 62 B 18/02, publ. 02.25.2000), containing an elastic casing, consisting of a bearing and a nose, and mating with the casing obturator. The bearing part of the body is made in the form of a hemisphere, the diameter of which corresponds to the maximum horizontal size of the half mask. In secant planes passing through the hemisphere, platforms are made for attaching filter cartridges and an exhalation valve. The contour of the obturator cross section is formed by arcs of circles, the bending angles of the obturation strip relative to the body and its width are of constant value throughout the large contour of the half mask. The contours of the carrier and bow parts of the body form a large contour of the half mask in the area of the shutter. The contour of the half mask in the area of the shutter in a plane perpendicular to the large contour is formed by two straight lines, mating with an arc of a circle.

The disadvantages of the half mask are the low values of the protective and ergonomic values of the respirator in connection with the occurrence of pain in the nose, wings of the nose, zygomatic bones - areas with a small thickness of the soft tissue layer and therefore susceptible to pain. This is explained by the small contact area of the obturation strip with the front surface due to the small values of the bend radius of the obturation strip. Large radii of the hem of the obturation strip increase the limitation of the field of view.

Known half mask for a respirator closest to the claimed and adopted as a prototype (US Pat. RU No. 2186597, IPC ⁷ A 62 B 18/02, publ. 10.08.2002), containing an elastic body consisting of a bow and a bearing parts with circular platforms having holes for attaching filter cartridges and an obturator mating with the housing. The contour of the half-mask body in the frontal plane in the obturator region consists of four mating arcs of circles, and in the plane perpendicular to the frontal one - of three mating arcs of circles. The angle of the hem of the obturation strip gradually increases along the contour of the body or has a constant value in the chin.

A half-mask respirator has higher protective and ergonomic values, since its design allows to reduce the pressure of the shutter on the skin of the face by distributing pressure along the obturation strip and transferring part of the force, which ensures the fastening of the respirator on the face, from the area of the face with increased pain ( zygomatic bones, nose wings) in the area with low pain perception (buccal and chin areas of the face). At the same time, protective (normalized coefficient of suction along the obturation strip) and ergonomic (small values of the field of vision restriction and pressure on the skin of the face) respirator parameters are provided.

However, the protective and ergonomic values of the respirator associated with the half mask are insufficient and it is not technologically advanced. This is due to the fact that due to the gradually increasing angle of bending, the position of the obturation strip depends on the shape of the contour of the half mask body, which violates the principle of constructing the obturation strip depending on the average values of anthropometric values and reduces the protective properties of the half mask. In addition, the half mask has a large volume of mask space, which leads to an increased concentration of carbon dioxide in the inhaled air. This is due to the location of circular pads with holes for attaching filter cartridges to a hemisphere with a radius equal to half the maximum size of the half mask. In addition, the location of the sites in the hemisphere limits the field of view, as the filter cartridges fall into the field of view. The low-tech respirator is explained by the need to manufacture three complex molds for production, for example, a frame with attachment points for filter cartridges to half masks of three growths, which reduces economic performance due to the impossibility of unifying them.

The present invention solves the problem of increasing the values of the protective and ergonomic values of the half mask by constructing an obturation strip depending on the average values of anthropometric values, reducing the volume of the mask space, expanding the field of view, as well as increasing the manufacturability and economic performance of respirators by making it possible to use one mold for the manufacture of attachments for filter cartridges to half masks of three growths.

To achieve the specified technical result, the design of the respirator half mask contains an elastic body consisting of a bow and a bearing part with platforms having openings for attaching filter cartridges and an obturator with a strip of obturation mating with the body, the body contour in the frontal plane in the obturator area consisting of four mating arcs of circles, and in a plane perpendicular to the frontal, of three mating arcs of circles, and the angle of the fold of the obturation strip is gradually changed It runs along the contour of the body or has a constant value in the chin, the following distinctive features are introduced:

- the angle of the bend of the obturation strip relative to the frontal plane of the half mask gradually increases from the nose to the wings of the nose, then gradually decreases in the region of the wings of the nose, buccal region and gradually decreases in the chin at a variable angle.

- holes for attaching filter cartridges are made on oval shaped platforms, their centers are located at the same distance from each other along the generatrix contour of the half mask body for all sizes, which is determined by the length of the generatrix for the first half mask growth.

In addition, the large axis of the oval-shaped pads is located in the plane passing through the centers of the holes for attaching the filter cartridges and the exhalation valve.

The implementation of the angle of the hem of the obturation strip relative to the frontal plane of the half mask is gradually increasing from the nose to the wings of the nose, then gradually decreasing in the area of the wings of the nose, buccal region and gradually varying in the chin (or constant in the chin) allows you to determine the angle of the hem of the obturation band a constant base, in this case, on a plane passing through the platform for attaching the exhalation valve parallel to the frontal plane. The counting of the angles of the hem of the obturation strip from a constant base leads to the fixing of angles in important sections of the obturator (nose bridge, nose wings, buccal region and chin), followed by a smooth connection of parts of the obturation strip, which improves the protective and ergonomic properties of the half mask.

The implementation of the oval-shaped pads allows to reduce the volume of the mask space, which leads to a decrease in the concentration of carbon dioxide in the inhaled air.

The location of the centers of the holes at the same distance from each other along the generatrix of the half-mask body contour for all sprouts, which is determined by the length of the generatrix for the first half-mask growth, makes it possible to increase the manufacturability and economic performance of the respirator by making it possible to use one mold for the manufacture of attachment points for filter cartridges to the half masks of three growths.

The location of the major axis of the oval-shaped pads in a plane passing through the centers of the holes for attaching the filter cartridges and the exhalation valve makes it possible to simplify the design and manufacture of the half mask.

The proposed design of the half mask for the respirator is presented by drawings, where figure 1 shows a front view of the half mask; figure 2 and 3 - vertical and horizontal sections of the half mask.

The half mask consists of an elastic body, including the carrier 1 and nose 2 parts and mating with the body obturator 3 with a strip of obturation. The contours of the carrier 1 and nasal 2 parts of the body form a large contour in the region of the obturator 3, which consists of the nasal 4, buccal 5 and chin 6 parts.

The bearing part 1 of the housing is used to secure the filter cartridges and the exhalation valve. In vertical planes touching the large and small contours in the μ-μ plane and intersecting at an angle of 50-70 °, oval-shaped pads 7 are made for attaching filter cartridges so that their contours along the major axis mate with the large and small contours of the half mask (Fig. 3).

The center of the pad 8 and the holes for attaching the exhalation valve are located in the μ-μ plane. The distance N depends on the anthropometric values of the face: for the Mongoloid race, it can be less, for the Nordic type of face - more than the average European. The μ-μ plane is located taking into account the condition of approximate equality of the moments of forces:

where F ₁ , F ₂ and q ₁ , q ₂ are the corresponding generalized forces and shoulders of the moments of forces;

p ₁ , p ₂ - local pressure of the obturation strip on the skin of the face, which in the direction of action of the forces F ₁ and F _2, respectively;

J ₁ , J ₂ - the corresponding elementary area of the strip obturation (and skin).

The design of the half mask provides the construction of the obturation strip taking into account the physiology of the body, in particular the physiology of tissues, taking into account the mechanical effect of the obturation strip, which affects the psyche through pain perception. The design of the obturator 3 allows you to remove excess pressure from areas of high pain perception and transfer them to areas of low perception - buccal and chin.

The large contour in the area of the shutter 3 (projection) is made in the form of four mating arcs: ab, bc, cd, de (Fig. 1) or three arcs of circles and a straight line segment W.

The construction of the upper bow 2 of the large obturator contour is performed taking into account the maximum vertical size N. An arc is drawn with a radius R ₂ from the center of O ₂ . The values of the radii R ₂ for different half masks are different and depend on the average anthropometric values of the race, age contingent, etc. For the half mask PR-01 of the second growth, R ₂ = 10 mm.

The conjugation of arcs at points b, c and d is carried out by the method of analytical geometry.

The formation of the obturation strip, its spatial position inside the half-mask affects the protective properties - the coefficient of suction along the obturation strip. In the proposed design, the angle α of the hem of the obturation strip is counted from a constant base — any plane parallel to the O-O frontal plane, for example, O′-O ′ or passing through the platform for attaching the exhalation valve. To form the angle of the hem of the obturation strip 3, five special sections of the obturator 3 with fixed angles were adopted: on the bridge of the nose in the AA plane, in the middle of the arcs ab, bc, in the μ-μ and AA plane in the chin.

In the vertical plane perpendicular to the front, the half mask contour (projection) in the area of the obturator is formed by three mating arcs fg, gh and hk.

The small contour of the half mask consists of an incomplete circumference of the platform 8 for attaching the exhalation valve, an arc of a circle of radius R ₃ and the arcs or segments of straight lines 9 mating with them.

The body of the half mask is formed between the large and small contours: the upper part of the half mask - by moving a straight line along the contours, in the lower - a convex surface.

Example. The half-mask of the respirator has a maximum vertical size H = 120 mm, horizontal L = 109 mm, with γ = H / L≈1.1, which is inherent in the Central European type of face. The half mask is formed by four arcs of circles of different curvatures in the frontal plane and three in the orthogonal frontal plane. The geometric values are selected as a result of instrumental measurements of five foreign half masks and domestic PR-7. As a result, the average values in mm are given in table 1.

N L r ₁ r ₂ R ₁ R ₂ l top bottom 120 109 3 four 40 10 12 twenty

The spatial position of the obturation strip is determined by the angle α ° of its bend in the characteristic sections of the obturator shown in table 2.

In plane AA, top On arc a-b On arc bs On the c-d arc In the plane AA, bottom 40 68 53 51 47

The sections between the characteristic sections smoothly connect, forming a continuous strip of obturation.

In the half mask, oval-shaped pads are made for attaching filter cartridges, the contours of which along the major axis are mated with the large and small contours of the half mask, which reduces the volume of the mask space and reduces the concentration of carbon dioxide in the inhaled air.

In order to reduce the production costs of respirators and increase the manufacturability of the production process by unifying the mounting blocks - bushings with triads of bayonet mounts, half-openings are made in the half mask on the oval platforms so that their centers are located at the same distance from each other along the generatrix of the body contour for all sizes, which is determined by the length of the generatrix equal to 2Z (figure 3) for the first growth of the half mask, and its holes for attaching the filter cartridges are shifted to the obturator. The values of the geometric quantities characterizing the structural elements of the proposed half mask are shown in table 3.

Rostov No. N mm L mm Generator length 2Z, mm 2r ₁ mm 2r ₂ mm proposed prototype
28
36 one 120 109 106 106 2 127 112 109 3 134 116 112

For the manufacture of prototypes of the half mask, a rectangular parallelepiped of easily processed material, for example viscous wood, with ribs H, L, N is used. Two contours are formed on two faces in the area of the obturator (see Figs. 1, 2) and a small contour of the body. Then draw up the obturator according to the values of its values r ₁ , α, l. A prototype is made of a half mask from a crude rubber mixture followed by gentle vulcanization. The prototypes of the half masks after the trial tests and decision making, after the stage of computer design and mold manufacturing, the half mask is made according to the well-known technology - pressing and vulcanization.

Thus, the use of the proposed half mask increases the values of the protective and ergonomic values of the respirator by constructing an obturation band depending on the average values of anthropometric values, reduces the volume of the mask space and, as a result, reduces the content of carbon dioxide in the inhaled air, expands the field of view, and also increases manufacturability and economic performance of the respirator by providing the ability to use one mold for the manufacture of fasteners I have filter cartridges for half masks of three growths.

Claims (2)

1. The half mask of the respirator, comprising an elastic body, consisting of a bow and a bearing parts with platforms having holes for attaching filter cartridges, and an obturator with an obturation strip mating with the body, the body contour in the frontal plane in the obturator area consisting of four mating arcs of circles, and in the plane perpendicular to the frontal, of three mating arcs of circles, the angle of the hem of the obturation strip changes smoothly along the contour of the body or has a constant value in the chin part, characterized in that the angle of obliquity of the obturation strip relative to the frontal plane of the half mask gradually increases from the nose to the wings of the nose, then gradually decreases in the area of the wings of the nose, buccal region and gradually changes in the chin at a variable angle, the holes for attaching the filter cartridges are made on platforms oval, their centers are located at the same distance from each other along the generatrix of the contour of the half-mask body for all sizes, which is determined by the length of the generatrix for the first Half of growth. 2. The half mask of the respirator according to claim 1, characterized in that the large axis of the oval-shaped pads is located in the plane passing through the centers of the holes for attaching the filter cartridges and the exhalation valve.

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