RU2186597C1 - Semimask for respirator - Google Patents

Abstract

FIELD: device for protecting individual's breathing organs from hazardous industrial environment. SUBSTANCE: semimask has portion adjoining to obturator and made in the form of four conjugated arcs of circle and portion arranged in vertical plane perpendicular to front plane of semimask and made in the form of three conjugated arcs of circle, with middle concave arc of circle extending into hemisphere. Obturator has portion adjoining to chin and extending in horizontal plane intersecting hemisphere and arranged below circular portions for attachment of filtering cartridges and expiration valve. Chin portion of semimask is formed as arc of circle extending inside hemisphere and conjugated with vertical arcs of circle of front part adjoining to cheeks. Width, radius and bending angle of obturator, which are forming its section contour are gradually increasing from upper nose part to chin part along entire perimeter of obturator contour or mentioned geometric values are constant in chin part thereof. EFFECT: increased efficiency by optimal distribution of pressure over obturator contour and reliable attachment. 3 dwg, 1 ex

Description

 The invention relates to personal protective equipment for respiratory organs of people in hazardous industries, in particular to the construction of half masks for respirators.

 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 filter half mask containing a housing and a shutter. The case has a complex three-dimensional shape, consisting of geometric shapes in the form of rectangles and triangles obtained by sequentially folding several layers of material, turning, bonding and straightening a flat elastic blank (see, for example, RF Patent 2020985, class A 62 B 18 / 02, 1992).

 The half mask has many folds to form the corners of the half mask elements. The half-mask obturator does not provide a tight fit to the face due to the formation of corrugations due to the repeated folding of the workpiece during the formation of the obturator.

 A known design of the half mask, the body of which is made of a flat figure in the form of an ellipse. Bulkness of the body is imparted by folds of material located at an angle to the major axis of the ellipse, fixed along the obturation strip (see, for example, RF Patent 2118902, class A 62 B 18/02, 1998).

 However, the presence of folds fixed in the obturation strip in this design reduces the tightness of its fit to the face and causes increased pressure of the half mask on the skin of the face in the folds.

 Known half mask containing a housing, a nasal plate and an obturator. The body of the half mask has the shape of a hollow cone made of a rectangular blank (see, for example, application for PM 99109249/20, class A 62 B 7/00, from 1999).

 The design drawback of this half mask is the relatively low stiffness of the materials used, which do not provide stability (frame) of the shutter over the obturation strip and, as a result, the high coefficient of half mask suction over the obturation strip.

 Known half mask for a respirator containing an elastic casing, consisting of a bearing and nose, and mating with the casing obturator with a strip of obturation. 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 for attaching filter cartridges and for the exhalation valve are made. The configuration of the obturator is formed by arcs of circles whose radii, bending angles and width of the obturation strip have constant values along the entire 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 design of the half mask is formed from elementary geometric figures: hemispheres, arcs of circles, straight lines and angles, which greatly simplifies the process of design development and manufacturing of molds for the production of half masks, while ensuring a tight fit of the half mask to the face along the obturation strip (see RF Certificate 14133, class A 62 B 18/02, 02.25.2000).

 However, the constancy of the values of the geometric quantities that determine the obturator along the entire large contour: the width of the obturation strip, the radii of the arcs of circles and the bending angles, is a significant drawback. So, for example, small values of the geometrical quantities forming the obturator do not ensure the reliability of fastening the half mask on the face at low tension by the headband. An increase in tightness leads to increased pressure on the skin, especially in the nose, which increases the coefficient of suction of the half mask, especially when turning the head. The increase in the width of the obturation strip and the radii of its hem does not allow to realize the design in the bow of the half mask and leads to a significant limitation of the field of view. A direct contour in a plane perpendicular to the frontal contour creates a lot of pressure on the skin of the face in the region of the zygomatic bones, despite the use of elastomers for the manufacture of half masks.

 The present invention solves the problem of reducing the pressure of the obturator on the skin of the face by optimally distributing the pressure over 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) to 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 limits) respirator parameters are provided.

 To achieve the specified technical result in a half mask for a respirator containing an elastic body consisting of a bow and made in the form of a hemisphere with a diameter equal to the maximum horizontal size of the half mask, the bearing part, in which secant planes are made circular platforms for attaching filter cartridges and exhalation valve , and the obturator mating with the body, the section contour of which is formed by the obturation strip, the radius and angle of its bend, while the contours of the carrier and nose parts of the body form a large contour in the area of the obturator, consisting of the nasal, buccal and chin parts, a large contour in the area of the obturator is made in the form of four mating arcs of circles, and a large contour in the area of the obturator in a vertical plane perpendicular to the frontal plane of the half mask is made in the form of three mating between an arc of circles, the middle of which is made concave into the hemisphere, and the obturator contour in the chin is made in a horizontal plane cutting through the hemisphere, passing below e circular platforms for attaching filter cartridges and an exhalation valve, in the form of a circular arc concave into the hemisphere, conjugated with vertical arches of the front contour of the buccal part, while the width of the obturation strip, the radius and the angle of its bend, forming the contour of the obturator cross section, are continuously increasing from the top the nasal to the chin part along the entire perimeter of the obturator contour or in the chin part of the obturator the indicated geometric values have constant values.

 Due to the fact that the obturator in the vertical plane perpendicular to the frontal plane of the half mask has a concavity in the zygomatic bone region (the middle of the three mating arcs of the obturator contour is concave into the hemisphere), the overpressure on the skin integument in this area is reduced. To reduce pressure in the nasal region, the obturator contour in this plane by an arc of a large circle of radius is assigned to the buccal region of the face. This made it possible to redistribute the pressure on the skin of the face and transfer part of the pressure to the buccal region with a large volume of tissue. The large pressure width due to the excessive force of the headband (elastic bands) necessary for the reliability of fastening the respirator on the face also helps to relieve great pressure from the nasal region, the most susceptible to pain, also contributes to the large width of the obturation band in the buccal and chin areas of the face. A small moment of generalized force in the lower half of the mask (small lever) causes moderate pressure in the nose (large lever, small force, therefore, low pressure). A smoothly varying (increasing) angle of obliquity of the obturation strip from the nasal to the chin ensures the formation of a local pressure vector close to the normal, which virtually eliminates the occurrence of a tangent (shear) component of the force adversely affecting facial tissues. The configuration of the obturation strip also contributes to this: in the chin part, it has the appearance of an arc concave inward in the hemisphere, having either the obturation band width increasing to the chin, the radius and angle of its bend, or constant values of these values in the chin part and taking into account the use of elastomers and the small thickness of the obturation band , it became possible to reproduce the wide range of geometric values of the configurations of the chins of the face.

 The reduction of the field of vision limits is achieved by small values of the bend radius of the obturation strip in the nose and wings of the nose, and the normalized coefficient of suction along the obturation strip is achieved by increasing the excess force created by the headband applied to the buccal and chin parts of the obturator, i.e. to the face with the least susceptible to pain skin.

 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 the 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 body is made in the form of a hemisphere, the radius R _{o of} which is equal to half the maximum horizontal size L, corresponding to the size of the half mask (figure 2 and 3). The vertical size H of the half mask (figure 2) is determined by the anthropometric value for this size of the half mask (according to GOST 17263-79).

The bearing part 1 of the housing is used to secure the filter cartridges and the exhalation valve. For mounting filter cartridges in secant planes passing through a hemisphere and intersecting at an angle of 50-70 ^o , platforms 7 are made (Fig. 3). The center of the platform 8 for attaching the exhalation valve is placed in the diametrical plane μ-μ, passing through the center of the hemisphere and the centers of the circular platforms 7 for attaching the filter cartridges, or can be shifted by a small angle in the vertical plane.

 The half mask is symmetrical about the vertical plane AA.

и

Сопряжение дуг в точках а и b производят с учетом вертикального размера Н и дуги

с радиусом R₂, определяемым антропометрической величиной для данной ростовки полумаски.The contour of the bow 2 of the shutter 3 is made of mating arcs of circles of mating between themselves and the cylindrical part in the buccal regions of radius R ₁ :

and

The conjugation of arcs at points a and b is made taking into account the vertical size H and the arc

with a radius R ₂ determined by the anthropometric value for a given half mask size.

(фиг.1).A large contour in the area of the shutter (projection) is made in the form of four mating arcs:

(figure 1).

окружностей. Средняя дуга

выполнена вогнутой внутрь полумаски, воспроизводя профиль лица в области скуловой кости.The large contour of the obturator in a vertical plane (projection) perpendicular to the frontal plane of the half mask is made in the form of three arcs interconnected

circles. Middle arc

made concave inside the half mask, reproducing the profile of the face in the zygomatic bone.

, сопряженной с обеих сторон с вертикальными дугами

фронтального контура (фиг.3).The lower part of the hemisphere is cut off by a horizontal secant plane νν, passing below circular sites for attaching filter cartridges and an exhalation valve. In the indicated secant plane νν, the obturator contour is made in the chin part, which has the form of an arc concave into the hemisphere

conjugated on both sides with vertical arcs

frontal contour (figure 3).

The contours of the carrier 1 and nose 2 of the body parts form a large contour of the half mask in the area of the obturator 3 with the perimeter P = 2 (P ₁ + P ₂ ), where P ₁ is the perimeter of the contour of the nose and buccal parts; P ₂ - the perimeter of the contour of the chin.

 The resulting large contour forms the obturator 3 with the obturation strip 9, while the contour of the obturator 3 is formed by circular arcs, the radii of which, the bending angles α and the width l of the obturation strip smoothly increase from the bow 4 to the chin 5. In the chin 5 of the obturator, these geometric values can have values increasing to the axis of symmetry AA or constant values along the entire length of the chin. In the plane parallel to the diametrical plane of the hemisphere section, a small half mask contour is made, the shape of which is determined by platform 8 and design considerations. The half mask is made of elastomer, for example, antiseptic formulations of rubber, plastisols.

 Structurally, the proposed half mask is implemented as follows.

=17 мм и

=21 мм соответственно.Example. Consider the half mask PR-01 of the 2nd growth. In accordance with GOST 17263-79 for this size, the maximum horizontal size is L = 102 mm, the maximum vertical size is H = 123 mm, the radius of the nozzles of the filter cartridges and the exhalation valve

= 17 mm and

= 21 mm, respectively.

Аналогично определяется расстояние от центра полусферы О до секущей плоскости для формирования в ней площадки 8 для клапана выдоха с учетом величины радиуса этой площадки.To build the configuration of the bearing part 1 of the half mask body, a hemisphere with a center O is selected, the radius of which R _o is equal to half the maximum horizontal size L of the half mask. On the hemisphere in secant planes located at an angle of 60 ^{o to} each other, round platforms 7 for attaching filter cartridges are made, and in the secant plane passing through the center O of the hemisphere and the centers of circular platforms 7, a round platform 8 for the exhalation valve is made. The distance N (normal) from the center of the hemisphere O to the circular areas 7 is determined from a right triangle:

Similarly, the distance from the center of the hemisphere O to the secant plane is determined to form a platform 8 for the exhalation valve in it, taking into account the radius of this site.

The lower part of the hemisphere is cut off by a horizontal secant plane νν at a distance of 35 mm from the center H of the hemisphere. After that, the center O ₁ of the circular arc is determined for conjugation of the straight line νν and a circle of radius R ₁ , with R ₀ = R ₁ + Ш ₁ (Fig. 1).

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.

проводят прямую - место центров сопрягающихся дуг. Радиус дуги сопряжения принимают из опыта - анализа отечественных и зарубежных полумасок, например, равным R_c=50 мм(фиг.1).The conjugation of the arcs at points a and b (the construction is shown for one half of the half mask) is performed by the method of analytical geometry, when a number of arcs are drawn from the centers O ₁ and O ₂ according to the condition:

draw a straight line - the center of the mating arcs. The radius of the conjugation arc is taken from experience - analysis of domestic and foreign half masks, for example, equal to R _c = 50 mm (figure 1).

окружностей радиусов R₃=50 мм, R₄=40 мм и R₁=35 мм. (фиг.2).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

circles of radii R ₃ = 50 mm, R ₄ = 40 mm and R ₁ = 35 mm. (figure 2).

In the plane νν, an arc of radius R ₅ ≈35 mm completes the large contour of the half mask (figure 3).

полумаски в области носовой части 2 корпуса формируется аналогично большому контуру abc полумаски. Поверхность корпуса в области носовой части формируется из совокупности множества отрезков прямых, имеющих общие точки с большим и малым контурами полумаски в носовой части корпуса. Раздельно формируется поверхность

и

За единичный шаг, перемещающий прямую, принимается единичный отрезок дуги меньшей длины, например,

и

Шаг отрезков дуг большего размера определяется из соотношений:

В полумаске ПР-01 (опытный образец) приняты следующие значения геометрических величин в плоскости сечения обтюратора: r₁=2 мм; r₂=6 мм; α₁= 30^°; α₂= 60^°; 1₁≈14 мм; 1₂≈24 мм. Плавное изменение значений геометрических величин сечения обтюратора осуществляется по условию: j₁=П₁/(l₂-l₁)=120/10=12 мм/мм; j_r=П1/(r₂-r₁)=120/(6-2)=30 мм/мм; j_α= П₁/(α₂-α₁) = 120/30 = 4 мм/^°;
где j - единичная мера, шаг по периметру П₁ большого контура обтюратора для каждой из геометрических величин сечения обтюратора (ширины 1 полосы обтюрации, радиуса г и угла α подгиба).Small contour

half masks in the nose region 2 of the body are formed similarly to the large contour abc of the half mask. The surface of the body in the area of the bow is formed from the totality of the plurality of line segments having common points with the large and small contours of the half mask in the bow of the body. Separately formed surface

and

For a single step moving a straight line, a single segment of an arc of shorter length is taken, for example,

and

The step of the segments of arcs of a larger size is determined from the relations:

In the half mask PR-01 (prototype), the following values of geometric values in the plane of the obturator cross section were adopted: r ₁ = 2 mm; r ₂ = 6 mm; α ₁ = 30 ^° ; α ₂ = 60 ^° ; 1 ₁ ≈14 mm; 1 ₂ ≈24 mm. A smooth change in the values of the geometric values of the section of the obturator is carried out under the condition: j ₁ = P ₁ / (l ₂ -l ₁ ) = 120/10 = 12 mm / mm; j _r = P1 / (r ₂ -r ₁ ) = 120 / (6-2) = 30 mm / mm; j _α = P ₁ / (α ₂ -α ₁ ) = 120/30 = 4 mm / ^° ;
where j is the unit measure, the step along the perimeter P _{1 of the} large obturator contour for each of the geometric values of the obturator cross-section (width 1 of the obturation strip, radius r and bending angle α).

For the convenience of manufacturing a mold for the production of a half mask, the step ΔP ₁ along the perimeter of the obturator should be taken the same for all geometric quantities, for example, ΔP ₁ = 12 mm. Then at this step: Δl = 1 mm; Δr = 0.4 mm; Δα = 3 ^° . Geometric values are easily measured with modern measuring instruments.

 The production of half masks from elastomers is carried out in a known manner - by thermal pressing followed by vulcanization. The difficulty lies in the manufacture of molds, especially by the method of sections. The proposed technical solution allows for three projections using elementary geometric shapes: a straight line, circular arcs, planes, spheres to uniquely design half masks and molds for their manufacture, which allows the use of advanced technologies - computer design and control of mold manufacturing technology.

Thus, the claimed technical solution allows:
- rationally distribute the pressure of the half mask on the skin of the face by increasing the pressure in the buccal and chin areas of the face, less susceptible to pain and bruises, which is achieved by a large area of the obturation band in this area, and reducing the moment of force acting on the nasal region due to clipping the lower part of the hemisphere with a horizontal secant plane;
- significantly reduce the pressure of the half mask on the skin in the area of the nose and cheekbones, the most susceptible to pain and naminas, by using mating arcs of circles that form the outline of the obturator in a plane perpendicular to the frontal plane of the half mask;
- reduce the values of the field of vision by using small values of the radius of the bend of the obturation strip in the nasal region;
- to ensure the pressure of the half mask on the skin of the face in the area of the wings of the nose is minimal, necessary to ensure a normalized coefficient of suction along the obturation strip;
- to simplify the manufacturing technology of molds for the industrial production of half masks in connection with a smooth change in the geometric values of the obturator cross-section from the bow to the chin according to simple rules.

Claims (1)

 A half mask for a respirator, comprising an elastic body consisting of a bow and made in the form of a hemisphere with a diameter equal to the maximum horizontal size of the half mask, the bearing part, in which cutting surfaces are made circular sections for attaching filter cartridges and an exhalation valve, and an obturator mating with the body , the contour of the section of which is formed by the obturation strip, the radius and angle of its bend, while the contours of the carrier and nose parts of the body form a contour in the area of the obturator, consisting of th, buccal and chin parts, characterized in that the contour in the area of the obturator is made in the form of four mating arcs of circles, and in a vertical plane perpendicular to the frontal plane of the half mask, it is made in the form of three mating arcs of circles, the middle of which is concave inward hemispheres, and in the chin part, the contour in the obturator region is made in a horizontal, cutting hemisphere, plane passing below circular platforms for attaching filter cartridges and an exhalation valve, in the form of a circular arc concave into the hemisphere, conjugated with vertical arches of the frontal contour of the buccal part, with the obturation strip width, radius and bend angle forming the obturator cross-section contour made smoothly increasing from the upper nose to the chin around the entire perimeter of the obturator contour or in the chin portion of the obturator indicated geometric values have constant values.

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