JPS6371270A - Respiration mask with replaceable filter - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention captures and retains particulate matter in the form of dust or smoke, such as an aerosol in the form of smoke, suspended in the air passing through a filter. The present invention relates to a respirator, commonly known as a dust mask, having a filter made of fibrous material.

[Conventional technology]

In its simplest form, such a respirator consists of a face piece formed from a stabilized fibrous material, which face piece is suitably adapted to extend over the user's nose and mouth. The molded or otherwise formed 0-face piece is held in place by elastic webbing attached to the face piece, and the webbing ties the respirator back around the user's nose and mouth. It is wrapped around the user's head to keep it elastically in place.

Such dust masks are completely temporary and disposable, and when the filter's filtration capacity drops to zero due to filter clogging, there is no other way than to throw away the dust mask and replace it with another unused mask. There is no way.

Improvements in such dust masks are disclosed in U.S. Pat. No. 4,319,567 by MaBidgon, U.S. Pat. No. 4,384,577 by Huber et al.
U.S. Pat. No. 4,454,881 by et al., which discloses that collapse of the face piece under the partial vacuum created by the user during inhalation, or malfunction of the respirator resulting in manual effort. Teach stabilization and improvement of filters to prevent collapse of face pieces inadvertently caused by.

These constructions have a removed appearance from more modern constructions, and still have the disadvantage that all respirators must be discarded after a relatively short period of use.

In addition to further impeding user inhalation when particulate matter builds up in the filter, certain types of discharge valves, as taught in U.S. Pat. No. 4,454,881 by Truber et al. Unless provided, user expulsion through clogged filter material will also become progressively obstructed. In the absence of a discharge valve, additional physical stress is placed on the user, especially when the user is performing strenuous manual labor. Additionally, such respirators or dust masks have a relatively large internal space that fills with exhaled air when the user exhales, and which then fills with exhaled air when the user inhales. Then, the discharged air is sucked in again. Heat from the inhaled air increases the temperature of the thick filter fiber layer (particularly thick in the case of metal fumes) upon exhalation. This heat is transferred to the incoming air during intake. Even a temperature increase as low as 2° to 3° causes significant psychological and physical discomfort to the user.

Other improvements to this type of respirator are disclosed in US patent application Ser. No. 270.957. The respirator has a face piece of soft rubber-like material fitted with a replaceable air filter in the form of a cartridge, the face piece being controlled by a conventional mouth valve. A six-sided piece that snaps onto the inlet of the valve includes two sided pieces attached to the face piece at two locations spaced from said inlet valve.
A heavy conventional discharge valve is provided separately. These discharge valves are actuated by the increase in pressure on the face piece as air is discharged by the user.

In this construction, the air drawn in through the filter is not subsequently discharged through the filter, but is instead passed through the two discharge valves as a bypass.

Although this construction has been successful in keeping the filter cartridge disposable and replaceable, it has the disadvantages of having to discard the entire filter cartridge after use and the associated additional costs, and the respirator has considerable bulk. It has the disadvantage that it becomes heavier as it increases in size and imparts significant inertia to the movement of the user's head. Also, in this construction, the face piece and the associated discharge valve require a relatively large internal space, in which the discharged air is trapped and subsequently re-inhaled by the user.

This latter type of respirator with replaceable filter is referred to as a semi-disposable respirator, in which the cartridge containing the filter material can be removed from the face piece for replacement with a disposable and unused cartridge. The face piece itself and its associated exhalation and inhalation valves are permanently a retaining part of the respirator.

[Problem that the invention seeks to solve]

The advantages of light weight, minimal inertia and enlarged area of filtration surface found in the previously known fully disposable respirator masks are retained as much as possible, while the disadvantages of the previously known respirator masks are eliminated. It is an object of the present invention to retain the advantages of known replaceable filter respirators in terms of filter exchangeability, while minimizing the disadvantages of such respirators: increased weight, kinetic inertia and retention of exhaled air. be.

[Means for solving problems]

Said object is achieved by the present invention by providing a respiratory mask which does not have the disadvantages of a separate discharge valve and increased weight and inertia as a whole and by incorporating the discharge valve directly into a valve body providing a mouth valve. achieved according to.

The replaceable filter element is supported by a frame and
The frame is purposefully shaped to be very light in weight and kinematically balanced against the user's head, and it also has the same filtration characteristics as traditional semi-disposable respirators. is arranged to support a fully disposable filter having a filtration area significantly larger than the filter area.

To achieve an increase in the effective area of the filtration surface and to provide kinematic balance of the filter frame, the frame is formed as a biplanar elongated member that wraps around the face piece and extends on either side of the user's face. .

Preferably, the discharge valve is positioned concentrically with the suction valve in the center of the frame, the frame having a plurality of ribs supporting the filter material spaced from a rear wall of the frame, the plurality of ribs having a large opening. Provides multiple channels for directing filtered air through the valve and into the face piece.

In this way, by appropriate selection of the materials used to form the face piece and the frame, the total weight of the assembly according to the invention can be reduced to a fraction of the weight of previously known respirator masks with replaceable filters. , and the weight can be kept slightly above that of previously known fully disposable respirator masks.

By reducing the weight and inertia of the respirator to the greatest extent possible, a source of discomfort for the user is removed and the respirator can be worn for long periods of time even when the user is under physically strenuous activity. make it legal across the board.

Furthermore, since the need for separate multiple discharge valves as previously known is completely eliminated, the volume occupied by the face piece can be reduced to just a fraction of the volume of a typical semi-disposable respirator. , thereby substantially reducing the entrapment of freshly exhaled air within the face piece.

Furthermore, by eliminating the normal exhalation valve of previously known replaceable filter respirators, the filter can be positioned very close to the user's face, thereby significantly reducing the user's field of vision. This would improve the design and at the same time minimize the inertial effects on the user's face caused by the respirator.

The primary use of the respirator of the present invention is in combination with welder shields. The respirator is sized small enough to be placed within the welding shield without affecting or interfering with the up and down movement of the shield.

〔Example〕

The invention will now be described in detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the respiratory mask of the invention.

1 to 4, a respirator with a replaceable filter is indicated generally at 10, the respirator comprising a face piece 12, to which a frame 14 is attached, and a flap L. - The mask 14 has a face piece 12 that surrounds the user's nose and mouth, and provides a continuous effect on the user's face even if there are various differences in the outline and shape of each user's face. Strap fasteners are provided for use in securing the respirator to the user's head to provide a secure seal.

The face piece 12 is molded or formed from a very soft and pliable rubber-like material, as is well known in the art, and these materials can be used for long periods of time without causing discomfort to the user. It can be worn on a person's face. Optionally, the face piece 12 may be made from a closed cell plastic foam material, which can further reduce the weight of an already fairly light face piece.

A frame, generally indicated at 14, is attached to the front portion of the face piece 12 to stabilize the frame 14 and to prevent the face piece from being pulled by the frame 14 towards the user's head when the frame 14 is pulled towards the user's head by the webbing 16. This support member 18 is preferably provided with a plurality of support members 18 on the two-sided piece in order to equalize the compressive stress applied thereon.
is surface piece 1 in any position when under compressive load.
It has particular utility in preventing inward collapse of the face piece 2 and preventing such non-uniform stresses from creating a discontinuity in the seal between the user's face and the face piece.

Frame 14 may be formed in any suitable manner using any suitable material, including light metals. However, it is more preferable to injection mold a plastic material such as acrylic resin that is lightweight, relatively rigid, and has relatively high impact strength.

It is more preferable that the frame 14 is formed as a single piece by injection molding, but it can also be formed by making a plurality of members of the same shape and combining them.

Frame 14 comprises a generally trapezoidal outer peripheral flange 20 that is symmetrical about a central ring 22 that is connected to flange 20 by a plurality of ribs 24 . The ribs have air flow channels between adjacent ribs.

Ring 22 provides support. That is, the ring itself forms a support for the discharge valve 26 supported on the spider 28 and for the suction valve 34 described below.

In some cases, the discharge valve 26 and the spider 28 supporting the discharge valve 26 can be formed as separate assembly elements that are pressed onto the central ring 22.

The rear side of the frame 14 is completely enclosed by a rear wall 30, which is either integrally formed with the frame 14 or secured to the frame 14 after formation.

A central opening 32 concentric with the support ring 22 is located at the rear so that air flowing within the plurality of channels provided by the outer peripheral flange 20, the plurality of ribs 24, and the rear wall flows towards and through the central opening 32. It is provided on the wall 30.

The rear wall 30 surrounds the central opening 32 and is connected to the surface piece 1.
2, the central ring 22 provides a support for the annular intake valve 34.

The outer peripheral flange 20 of the frame 14 is provided with rivets that can secure a plurality of tongues or ribs 38 formed on the peripheral flange 40 to a filter retaining member 42, which 20, is configured to surround and retain a replaceable filter member 44 in abutting relationship with the plurality of ribs 40 and the central ring 22 of the frame 14.

The filter retaining member 42 is perforated with a sufficient number of holes to minimize interference with airflow through the filter member 44 and engages the periphery of a circular opening 48 in the filter member 44; It has a central annular portion 46 configured to grip and hold the filter member 44 relative to the central ring 22 .

The filter holding member 42 is provided with a deflection guard 50 for deflecting air discharged downward from the rear surface of the welder shield from both eyes of the user in order to prevent the lenses from fogging up when in use. It is convenient if the central annular portion 46 is overlapped with the central annular portion 46 .

The locking tongue 38 is positioned asymmetrically with respect to the frame 12 and the filter retaining member 42 such that the frame 12 receives the filter retaining member only in the correct orientation with said deflection guard 50 having its outlet facing downwardly. It is good.

As shown in the figures, the lateral portions of the frame 14 can face the user's face and extend to the opposite sides of the face piece 12, so that when viewed in a horizontal plane, the lateral portions are substantially formed to extend.

Assembly is completed by attaching the strip 16 to the frame 14 by means of buckles 52 which may be integrally formed with the frame 14 or may be subsequently attached in any suitable manner.

As shown in more detail in FIG. 4, the face piece 12 is attached to the frame 14 by sandwiching the face piece 12 within a groove 54 provided by the rear wall 30. The grooves 54 have a relatively large circumferential extent, so that the weight of the face piece can be reduced considerably, thereby reducing the weight of the respiratory mask.

A discharge valve 26 is secured within the central ring 22 and positioned on the outer side of the spider 28. The discharge valve 26 is made from a highly flexible but dimensionally stable sheet material;
At its edge it hits on the valve seat provided by the central ring 22, so that air is drawn in through the central ring 22 and is free to bend away from the spider 28 and the central ring 22, As a result, the air is in the center ring 2
2, thus providing a discharge valve that is integral with and positioned inside the central ring 22.

A suction valve 34 is provided on the outside of the center ring 22 .
It can be installed by any convenient method such as ultrasonic upsetting into the material. The intake valve 34 is also made of a highly flexible and dimensionally stable material and extends radially from the outer circumference of the central ring 22 with a valve seat provided by the rear wall 30 of the frame 14. They are in an abutting relationship.

The assembly of the two valves is completed by the assembly operation method described below.

correctly positioned on the frame 14 and the frame 14
With a filter member 44 held in place by snapping a filter retaining member 40 onto the peripheral edge of the and through a plurality of channels extending between the ribs 24 of and reaching the central opening 32.

When inhaled by the user, a drop in pressure occurs inside the face piece 12 and the throttle valve 58 lifts at its edge, allowing the passage of filtered air into the inside of the face piece with minimal resistance. . In this case, the resistance to airflow is minimized by the very large effective area 44 of filter member 44, so that the resistance to airflow between central opening 22 and intake valve 58 is negligible.

When the user exhales air, an increase in pressure occurs inside the face piece 12 and the inlet valve 58 closes immediately and the outlet valve 56 closes.
opens immediately, allowing the evacuation of the air discharged from the inside of the face piece 12 to the atmosphere with extremely little resistance.

The discharged air is thus unable to enter into the channels between the plurality of ribs 24 and into the filter member;
The channels remain occupied with clean, unadulterated air throughout the period of exhalation by the user.

Furthermore, since the contained volume of the surface piece 12 is minimal,
A very small amount of the exhaled air remains trapped within the face piece 12 after the user has finished exhaling. Furthermore, since the effective area of the filter member 44 is extremely large, the resistance to air drawn through the filter member 44 is
Even under partially used and partially obstructed conditions, the interval period between filter element replacements is thus lengthened.

The filter material itself is removed by unsnapping the filter retaining member 42, removing and discarding the used filter member 44, and repositioning the replacement filter member 44 over the central gripping ring 62, and then repositioning the filter member in place. frame 14,
By snapping the filter member onto the filter retaining member 42 to retain on the plurality of ribs 24 and the central gripping ring 22 to inhibit leakage of contaminated air over the peripheral edge of the filter member 44. , can be easily replaced.

During use of a conventional respirator, the user exerts a considerable amount of force on the respirator due to the relatively rapid velocity of the user's head movements. This may cause discomfort to the user or may move the edge of the face piece 12 out of sealing engagement with the user's face allowing inhalation of contaminated air by the user.

Such a possibility is largely avoided on the basis of the invention, in which the frame 14 is formed as two planes, so that all parts of the frame 14 are placed as closely as possible to the user's face.

Furthermore, the webbing 1 is directly attached to the frame 14 which has a two-plane shape.
6 provides resistance to movement of the frame 14, i.e. the straps 16 resist any lateral movement of the ends of the frame 14 or any movement of the frame 14 about the general central axis of the respirator. Resist rotational movement.

It will be appreciated that the construction of the respirator described above describes a preferred embodiment of the invention and that various modifications to this construction may be made without departing from the scope of the claims. For example, the number of ribs 24 may be increased,
The ribs 24 may be arranged in an arrangement other than radially towards the central gripping ring 22 or the ribs 24 may retain unrestricted channels for air flow between the ribs and into the central hole 32. good. Also, although the filter retaining member is shown as having a generally rectangular square shape to permit airflow to the filter member 44, other convenient shapes of perforated grids may be used. Also, any other convenient means for attaching the filter retaining member to the frame 14 or for attaching the frame 14 to the face piece 12 may be used.

The provision of concentric inlet and outlet valves is central to the inventive idea of the present invention, which minimizes the resistance to air flow into and out of the face piece, and which is common in the prior art. This results in a substantial weight reduction for the total weight of the respirator compared to the weight of a respirator with an independent exhalation valve.

Another advantage arising from the use of such concentric suction and discharge valves is that the moisture created in the face piece by condensation of the air exhaled by the user is concentrated at the discharge valve 56, The point is that moisture can be easily evacuated from the mask via the deflection guard 50.

Advantageously, the concentric suction and discharge valves are molded parts that are cut out in one operation, with the outer diameter of the inner ring being the same as the inner diameter of the outer ring. Manufacturing two valves at the same time in one stroke of the cut-off mold meets economics and at the same time virtually eliminates waste.

FIG. 5 shows a variant of the respiratory mask of the invention, in which the filter 60 is formed as a fully integrated semi-assemble.

That is, the semi-assembled portion is snapped onto the cylindrical tip 62 of the valve structure having a slightly modified shape.

In FIG. 5, the filter assembly includes face piece 12.
It is formed completely separate from the face piece and is designed to be snapped onto the face piece nose 62 and removed therefrom for replacement.

To enable installation of filter semi-assembled,
The central ring 22 extends forward of the face piece 12, and is provided with a spring-loaded latch 66 at the forwardmost end of the central ring 22.
Such launches can be easily formed during molding of the central ring and associated structure.

As in the previous embodiment, a spider 28 is provided inside the central ring, on which a highly flexible but dimensionally stable throttle valve 26 is arranged.

Another spider 32a is provided outside the center ring 22, and the spider 32a supports and positions the center ring 22 inside the opening of the plate 68 for 82, and the mounting plate 68 is placed on the surface piece 12. The necessary fittings 70 are provided.

The filter assembly, shown generally at 60 in this embodiment, is a fully preassembled filter unit that not only includes filter material 44 but also passes through a filter such as activated carbon, diatomaceous earth, etc. They may include materials that treat the air they carry, or they may include fibrous materials that are capable of being electrostatically charged.

The filter 44 is encased inside an extremely thin walled shell made from thermoformable plastic sheet;
The rear side 30 of the shell is a cavity formed to provide a plurality of ribs 24a providing air channels, similar to the previous embodiment, and the cavity extends to a central opening 32a in the rear wall 30a. ing.

The front wall 42a is formed as a porous surface to allow passage of air into and through the filter, and the front and rear walls are formed in any convenient manner to provide a closed package for the filter material contained therein. They are welded to each other and have projecting parts for attaching a plurality of webbing straps.

To replace a used filter assembly with a new one, the user depresses the spring-loaded launch to remove the filter assembly 60 from the face piece 12 and valve assembly 64, and then inserts the replacement filter assembly into the face piece. It is only necessary to slide it past the tip 62 of the tube.

Many other variations are contemplated within the scope of the claims, and the embodiments described above are merely illustrative of more preferred embodiments within the scope of the claims.

[Brief explanation of the drawing]

1 is a front perspective view of a respirator with a replaceable filter according to the present invention, FIG. 2 is an exploded perspective view of the respirator of FIG. 1, and FIG. 3 is an exploded perspective view of the respirator of FIG. FIG. 4 is a cross-sectional view of the respirator shown in FIG. 1 cut along a horizontal plane; FIG. 5 is another embodiment containing a filter semi-assembly that can be completely disposed of; FIG. FIG. 10... Respiratory mask, 12... Face piece, 1
4...Frame, 22...Central ring, 2
6...Discharge valve, 34...Suction valve, 42...
- Filter holding member, 44...filter member.

Claims (1)

[Claims] 1. Consists of a face piece formed from a rubber-like material, an inlet valve and an outlet valve associated with the face piece, and a filter cartridge through which air is sucked into the face piece. In a respirator, the inhalation valve and the exhalation valve are coupled together into a single assembly, and an annular inhalation valve is disposed concentrically radially outwardly of the exhalation valve, carried by the valve assembly and arranged concentrically. A respirator, characterized in that the inlet valve is in communication with a substantially laminar filter assembly extending laterally from the axes of the two valves. 2. the valve assembly having a substantially rigid valve body positioned within the forward aperture of the face piece and directly connected to the face piece; the valve body having a central cylindrical wall; 2. A respiratory mask according to claim 1, wherein the inside of the cylindrical wall provides a valve seat for an exhalation valve and the outside of the cylindrical wall provides a valve seat for an inhalation valve. 3. the cylindrical wall has an inner spider member for supporting the discharge valve and providing direct support for the annular suction valve;
3. A respiratory mask according to claim 2, wherein said cylindrical wall is supported from said valve body by second spider means. 4. The filter assembly is supported directly from the valve body and has an impermeable back wall having an edge extending into a peripheral frame member, the back wall having a plurality of spaced ribs extending forwardly. on a forwardly provided surface for the support for positioning the filter element, the plurality of ribs directing filtered air directly to the intake valve in a substantially unobstructed manner. A respiratory mask according to any one of claims 1 to 3, which provides a channel. 5. A perforated retaining member removably attachable to a peripheral frame of the rear wall to keep the filter element in position relative to a plurality of spaced ribs. A respiratory mask according to item 4. 6. The shape of the filter assembly seen from above is 2.
a shape that forms a plane and extends laterally of the face piece towards both sides of the face piece, thereby greatly increasing the filtration surface area and resulting from rapid movements of the user's head on the face piece. 6. A respirator according to claim 4 or claim 5, wherein the respirator has minimal stress. 7. A patent comprising a lace-like member directly attached to said filter assembly, thereby allowing natural movement of the face piece relative to the filter assembly and isolation of the face piece from stresses imparted to the lace-like member. A respiratory mask according to any one of claims 1 to 6. 8. The respiratory mask according to any one of claims 1 to 7, which has an air deflection member that is combined with the discharge valve and directs the discharged air downward from the user's eyes. .