Description FILTER-REPLACEABLE GAS MASK

Technical Field

[1] The present invention relates to a filter-replaceable gas mask and, more particularly, to a filter-replaceable gas mask that can be used in general industrial fields where toxic gases are generated and nuclear power plants where radioactive materials may exist, the gas mask designed to allow a user to easily breathe through a filter cartridge with two filter canisters while assuring increased visibility in the upward, downward, left and right directions. Background Art

[2] In general, gas masks are worn on the face of a user in order to prevent infiltration into a human body of harmful contaminants generated in contaminated areas, emergency areas, air-polluted industrial fields, radioactively contaminated nuclear power plants, and so forth. The gas masks are classified into a full-face gas mask for protecting the whole face including the eyes and the respiratory organs and a half- face gas mask for protecting only the respiratory organs.

[3] As compared to the full-face gas mask, the half-face gas mask is simple in structure and provides a good wearing sense. For that reason, the half-face gas mask is frequently used in the industrial fields where there is no need to protect the eyes.

[4] In recent years, it is obligatory to furnish gas masks in the public areas where a large number of peoples are gathered together with the high risk of firing or other accidents, e.g., in theaters and subway stations. In such areas, a mask storage container is provided in a specified place to store gas masks therein.

[5] Most of the gas masks thus stored are reusable full-face gas masks each having a rubber-made mask body and a purifying canister. In usual instances, the mask body and the purifying canister are separately stored in a dismantled state.

[6] In case where the gas masks are stored with the purifying canister combined with the mask body, active carbon particles or paper filter elements used as a filter material of the purifying canister tend to absorb moisture and impurities present in the air. Thus, the gas masks undergo sharp reduction in their purification efficiency and may probably fail to exercise their purification capability at the very moment when such a need exists indeed. In most of the full-face gas masks, therefore, the purifying canister is put into, e.g., a vinyl pack, and is stored apart from the mask body.

[7] If the purifying canister is not combined with the mask body and stored independently of the same, there would be no ample time to attach the purifying canister to the mask body or difficulties may be encountered in doing so in case of occurrence of

an emergency situation such as firing or the like. Therefore, it is likely that the gas masks cannot be used when an emergency situation occurs in reality.

[8] In the conventional gas masks as described above, the mask body is made of rubber and has a surface coated with paint. It is often the case that the mask body contains foreign materials.

[9] When wearing the gas masks, a user may feel unpleasant due to the offensive odor emitted from the gas masks. The ingredients of the gas masks may adversely affect the skin of the user. The user may feel a sense of compression due to the heavyweight nature of the purifying canister. In addition, a problem is posed in that, when the gas masks are worn by the user, the purifying canister obstructs the user's field of vision in the downward direction.

[10] In particular, the gas masks used in nuclear power plants are reused after the mask body and the purifying canister are all decontaminated in order to avoid radioactive contamination. Since a prolonged period of time is taken in reducing the radioactivity in case of the purifying canister, it is time-consuming to decontaminate the gas masks.

[11] On the other hand, the half- face gas mask has no eye-covering portion and therefore provides an improved wearing sense as compared to the full-face gas masks. However, the half-face gas mask suffers from the problems similar to those noted above in respect of the full-face gas mask. In addition, there is a possibility that the mask holding force and the masking effect may be reduced if the gas mask does not conform to the face of a user in shape and size.

[12] As a solution to the afore-mentioned problems, the present inventor has proposed an integral filter type gas mask which was matured into Korean Patent No. 10-0604002. With the gas mask disclosed in this patent, a filter cartridge is fitted to a mask body, and a head band is connected to the filter cartridge so that a user can wear the gas mask on the head using the head band.

[13] The integral filter type gas mask configured as above has a drawback in that, if the lifetime of a filter built in the gas mask comes to an end during its use, the user wearing the gas mask must go out of the working site to replace the gas mask with a new one before coming back to the working site. Otherwise, a new alternative worker must be put into the working site in order to continuously perform the tasks assigned to the user of the gas mask. This is because the head band for use in wearing the gas mask is directly connected to the filter cartridge, thereby making it impossible to replace the filter cartridge in the working site. This leads to a problem of lengthening the working time in a dangerous area.

[14] With the integral filter type gas mask noted above, the air is drawn through a single filter cartridge, which makes it difficult for the user to breathe while performing his or her tasks. Moreover, the protruding portion on the front surface of the gas mask, par-

ticularly the nose portion of the gas mask, obstructs the user's field of vision. [15] In the integral filter type gas mask mentioned above, an exhaust port is arranged in the lower portion of the gas mask and an intake port is formed above the exhaust port, which restricts the size of the filter cartridge attached to the gas mask. In addition, since the air flows primarily through the lower portion of the gas mask, the intake port arranged in the upper portion is disadvantageous in improving the flow of air.

Disclosure of Invention

Technical Problem [16] In view of the above-noted problems inherent in the prior art, it is an object of the present invention to provide a gas mask that allows a user to easily breathe through a single inlet port, while forming filter cartridges into two filter canisters. [17] Another object of the present invention is to provide a gas mask that can be safely used in a gas leaking area and a radioactively contaminated area. [18] A further object of the present invention is to provide a gas mask that makes it possible to readily detach and replace a filter cartridge when the gas mask is in use or repaired. [19] A still further object of the present invention is to provide a gas mask that allows a user to easily breathe through an intake port arranged near the mouth and the nose below an exhaust port. [20] A yet still further object of the present invention is to provide a gas mask that can enjoy a wide field of vision in the upward, downward, left and right directions.

Technical Solution

[21] With these objects in view, there is provided a filter-replaceable gas mask wearable by a user having a face, a mouth, a nose and cheeks, comprising:

[22] a mask body for covering the mouth and the nose when the gas mask is worn by the user, the mask body having a front surface and a peripheral edge;

[23] a filter cartridge replaceably attached to the mask body, the filter cartridge being formed to extend over the cheeks when the gas mask is worn by the user;

[24] a wearing base frame attached to the front surface of the mask body, the wearing base frame being arranged between the mask body and the filter cartridge; and

[25] a headband unit connected to the wearing base frame for enabling the user to wear the gas mask.

[26] In the filter-replaceable gas mask, the mask body may include a cover portion for covering the mouth and the nose, a contact rim portion extending inwardly from the edge of the mask body, an exhaust flap unit fitted to an upper region of the cover portion and an intake flap unit fitted to the cover portion in a position below the exhaust flap unit.

[27] In the filter-replaceable gas mask, the contact rim portion may be formed into a specified width to ensure that the mask body comes into close contact with the face of the user.

[28] In the filter-replaceable gas mask, the exhaust flap unit may include a first flange arranged to make contact with a rear surface of the cover portion, an exhaust passage extending forwardly from the first flange, a first rib formed in a rear end of the exhaust passage, and an elastically deformable exhaust flap attached to the first rib for openably closing the exhaust passage.

[29] In the filter-replaceable gas mask, the wearing base frame may have a flap protection plate for protecting the exhaust flap and a vent hole formed around the flap protection plate.

[30] In the filter-replaceable gas mask, the intake flap unit may include a second flange arranged to make contact with a rear surface of the cover portion, an intake passage extending forwardly from the second flange, a second rib formed in a rear end of the intake passage in alignment with the second flange, an elastically deformable intake flap attached to the second rib for openably closing the intake passage and a cartridge holder protruding forwardly from the second flange, the cartridge holder having an engagement hole.

[31] In the filter-replaceable gas mask, the wearing base frame may have an insertion opening through which the intake flap unit protrudes forwards and a plurality of band connection legs extending away from the insertion opening in different directions, the headband unit being connected to the band connection legs of the wearing base frame.

[32] In the filter-replaceable gas mask, the filter cartridge may include a central fitting body having an intake passageway formed therethrough, a pair of filter canisters extending from the central fitting body to at least partially cover the cheeks of the user, and an one-touch engagement claw protruding downwardly from the central fitting body so that the one-touch engagement claw can engage with the cartridge holder of the intake flap unit.

[33] In the filter-replaceable gas mask, each of the filter canisters may include a base case, a case cover coupled to the base case, the case cover having a plurality of pores through which an air is inhaled, and a filter received between the base case and the case cover for performing a filtering and decontaminating function.

[34] In the filter-replaceable gas mask, the headband unit may include a plurality of ex- tendible straight bands anchored to the band connection legs of the wearing base frame and a buckle fixed to the extendible straight bands.

Advantageous Effects

[35] With the filter-replaceable gas mask in accordance with the present invention, the

field of vision is widened in the upward, downward, left and right directions because the filter cartridge is attached to the intake port below the exhaust port in such a fashion as to extend over the user's cheeks. Furthermore, it is possible to rapidly and easily replace the filter cartridge because the filter cartridge is detachably attached to the cartridge retainer through a one-touch engagement claw. In addition, since the filter canisters are formed on the opposite lateral sides so that the air can be inhaled through the two filter canisters, the air intake area is increased, thereby enabling the user to breathe with ease. Brief Description of the Drawings

[36] Fig. 1 is an exploded perspective view showing a filter-replaceable gas mask in accordance with the present invention.

[37] Fig. 2 is a perspective view of the gas mask shown in Fig. 1, with the respective parts assembled together.

[38] Fig. 3 is a side elevational section view of the gas mask shown in Fig. 2.

[39] Fig. 4 is a front view of the gas mask shown in Fig. 2.

Best Mode for Carrying Out the Invention

[40] Hereinafter, one preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[41] Fig. 1 is an exploded perspective view showing a filter-replaceable gas mask in accordance with the present invention. Fig. 2 is a perspective view of the gas mask shown in Fig. 1, with the respective parts assembled together. Fig. 3 is a side elevational section view of the gas mask shown in Fig. 2. Fig. 4 is a front view of the gas mask shown in Fig. 2.

[42] Referring to Figs. 1 and 2, the filter-replaceable gas mask of the present invention includes a mask body 4 formed to cover the mouth and the nose of a user, a wearing base frame 6 fixed to the front surface of the mask body 4, a filter cartridge 8 attached to the mask body 4 and the wearing base frame 6 for introducing the air through two passageways, and a headband unit 10 connected to the wearing base frame 6 and used in fixing the gas mask to the head of a user.

[43] As can be seen in Figs. 1 and 3, the mask body 4 includes a generally dome-like cover portion 14 for covering the mouth and the nose of a user, the cover portion 14 having a couple of fixing lugs 12, a contact rim portion 16 extending inwardly from the edge of the cover portion 14, an exhaust flap unit 18 fitted to the upper region of the cover portion 14, and an intake flap unit 20 fitted to the cover portion 14 in a position just below the exhaust flap unit 18.

[44] The mask body 4, which covers the facial region including the mouth and the nose, is preferably made of rubber or silicon which provides a good wearing sense without ex-

cessively compressing the face. The contact rim portion 16 is formed along the edge of the mask body 4 with a generally constant width so that it can make close contact with the facial surface.

[45] The exhaust flap unit 18 includes a first flange 24 arranged to make contact with the rear surface of the cover portion 14, an exhaust passage 26 extending forwardly from the first flange 24, a first rib 28 formed in the rear end of the exhaust passage 26, and an elastically deformable exhaust flap 30 attached to the first rib 28 for openably closing the exhaust passage 26. The exhaust passage 26 is formed into a generally circular shape. When exhaling the air, the exhaust flap 30 is lifted outwardly at one end to open the exhaust passage 26. The exhaust flap 30 is made of rubber or silicon and is attached to the first rib 28 from the outside. The wearing base frame 6 has a flap protection plate 52 and a vent hole 32 formed around the flap protection plate 52. The exhaust flap 30 is protected by the flap protection plate 52.

[46] The intake flap unit 20 includes a second flange 36 arranged to make contact with the rear surface of the cover portion 14, a generally rectangular intake passage 38 extending forwardly from the second flange 36, a second rib 40 formed in the rear end of the intake passage 38 in alignment with the second flange 36, an elastically deformable intake flap 42 attached to the second rib 40 for openably closing the intake passage 38, and a cartridge holder 46 protruding forwardly from the second flange 36, the cartridge holder 46 having an engagement hole 44.

[47] The intake flap unit 20 is arranged below the exhaust flap unit 18 in a neighboring relationship with the mouth and the nose so that the user can inhale the air with ease. The intake flap 42 of the intake flap unit 20 is made of silicon or rubber into a generally rectangular shape. The intake flap 42 has a fixing lug 48 inserted through the second rib 40 in the forward direction. Since the intake flap 42 is press-fitted in one direction, it is possible to attach and detach the intake flap 42 in a convenient manner as compared to the conventional intake flap which is fitted in place through a rotational operation. The intake flap 42 is not limited to the rectangular shape but may be formed into various kinds of other shapes. The intake flap 42 is lifted backwards during inhalation so that the air can be introduced through the intake passage 38. During exhalation, the intake flap 20 is closed into contact with the peripheral edge of the intake passage 38 so that the air can be prevented from flowing through the intake passage 38.

[48] The wearing base frame 6 has a plurality of fixing holes 50 formed in the lower region thereof, an insertion opening 52 formed between the fixing holes 50 so that the intake flap unit 20 and the cartridge holder 46 can protrude forwards therethrough, a flap protection plate 54 surrounded by a vent hole 32, the flap protection plate 54 being arranged above the insertion opening 52 the protect the exhaust flap 30, and a plurality of band connection legs 56 extending away from the insertion opening 52 and the flap

protection plate 54 in different directions. Each of the band connection legs 56 has a band insertion slot 58 through which the blow-mentioned extendible bands 78 of the headband unit 10 is inserted.

[49] The wearing base frame 6 is arranged on the front surface of the mask body 4 to ensure that the mask body 4 is pressed against the facial surface under a uniform pressure when the headband unit 10 is tightened. To this end, the band connection legs 56 of the wearing base frame 6 are arranged in an X-like pattern.

[50] The filter cartridge 8 includes a central fitting body 62 having an intake passageway formed therethrough, a pair of filter canisters 60 extending from the central fitting body 62 to the left and right sides to at least partially cover the cheeks of the user, and an one-touch engagement claw 64 protruding downwardly from the central fitting body 62 so that it can engage with the cartridge holder 46 of the intake flap unit 20.

[51] Although the one-touch engagement claw 64 is arranged in the lower portion of the central fitting body 62 according to the present embodiment, it may be possible to form the one-touch engagement claw 64 in the upper or lateral portion of the central fitting body 62.

[52] Each of the filter canisters 60 includes a base case 66, a case cover 70 coupled to the base case 66, the case cover 70 having a plurality of pores 68 through which the air is inhaled, and a filter 72 received between the base case 66 and the case cover 70 for performing a filtering and decontaminating function. By forming the filter cartridge 8 into a generally C-shape in this manner, it is possible to widen the user s field of vision and to assure easier replacement of the filter cartridge 8.

[53] The central fitting body 62 has a stopper portion 74 engaging with the intake flap unit 20, which makes it possible to attach the filter cartridge 8 in an easy and accurate manner. Furthermore, the filter cartridge 8 has a plurality of guide ribs 76 that assists in guiding the flow of the air toward the intake passage 38.

[54] The base case 66 and the case cover 70 of the filter cartridge 8 are air-tightly coupled together to prevent any leakage of the air. The filter cartridge 8 employed in the present invention conforms to the facial surface when the gas mask is worn by the user. Therefore, the filter cartridge 8 can be kept in close contact with the facial surface with no or little possibility of displacement.

[55] The headband unit 10 includes a pair of extendible upper straight bands 78 anchored to the band insertion slots 58 of the two upper band connection legs 56, a generally elliptical loop band 80 connected to the upper straight bands 78 and positioned at the back of the user's head when the gas mask is worn, a pair of extendible lower straight bands 78 anchored to the band insertion slots 58 of the two lower band connection legs 56, and a buckle 82 fixed to the free ends of the lower straight bands 78.

[56] Next, description will be made on how to assemble and use the gas mask described

above. The manner of assembling the gas mask will be first set forth.

[57] The exhaust flap unit 18 is fitted to the aperture formed in the upper region of the mask body 4, and the intake flap unit 20 is fitted to the aperture formed in the lower region of the mask body 4 so that the cartridge holder 46 can protrude forwardly.

[58] Then, the wearing base frame 6 is attached to the front surface of the mask body 4, at which time the upper portion of the wearing base frame 6 is coupled to the exhaust flap unit 18, with the fixing holes 50 fitted to the fixing lugs 12.

[59] Once the wearing base frame 6 is attached to the mask body 4, the filter cartridge 8 is combined with the intake flap unit 20, thereby completing fabrication of the gas mask. When combining the filter cartridge 8, the central fitting body 62 is fitted to the exhaust flap unit 18 in such a way that the stopper portion 74 of the central fitting body 62 engages with the engagement groove 37 of the intake flap unit 20. At this time, the one-touch engagement claw 64 is also engaged with the cartridge holder 46. In order to detach the filter cartridge 8, the one-touch engagement claw 64 is pushed and the lower end portion of the filter cartridge 8 is pulled away from the mask body 4. By doing so, it is possible to replace the filter cartridge 8 in an easier manner.

[60] Once the filter cartridge 8 is attached to the mask body 4, the loop band 80 of the headband unit 10 is put on the back of the user's head, and the length of the upper straight bands 78 is adjusted at the user's desire. Then, the lower straight bands 78 are wound around the back of the user's neck, and the buckle 82 is locked. Thereafter, the tension of the lower straight bands 78 is suitably adjusted to hold the gas mask against any movement. Thus, the wearing process of the gas mask comes to an end.

[61] Next, description will be made on the air inhalation and exhalation operation through the gas mask worn by the user as mentioned above.

[62] During the inhalation process, the air is introduced through the two filter canisters 60 of the filter cartridge 8. At this time, the air possibly polluted is decontaminated and filtered by the filter 72. The air thus filtered flows along the guide ribs 76 formed within the filter cartridge 8 toward the intake passage 38. Then, the air is introduced into the mask body 4 by pushing the intake flap 42 into an open state.

[63] The user inhales the air thus introduced and then exhales the same. The air exhaled passes through the exhaust passage 26 by pushing the exhaust flap 30 into an open state. Then, the air is discharged to the outside through the vent hole 32 formed around the flap protection plate 54.

[64] After the gas mask is used for a specified period of time, the filter cartridge 8 is replaced with a new one. If the one-touch engagement claw 64 is pushed out of engagement with the cartridge holder 46, the filter cartridge 8 comes into an unlocked state. Then, the filter cartridge 8 is separated from the exhaust flap unit 18 and disposed in a suitable manner. A new filter cartridge 8 is attached in the reverse order.

[65] The gas mask of the present invention configured as above can be stored in a mask storage container placed in public areas or nuclear power plants. At this time, the gas mask is stored in a fully assembled state for immediate use in an emergency situation. [66] Furthermore, the gas mask of the present invention provides a wide field of vision because the filter cartridge is designed to minimize obstruction of the eye sight.

Moreover, the two filter canisters having increased air intake capacity helps the user breathe easily and conveniently. [67] In addition, the gas mask of the present invention can be repeatedly used for an extended period of time by merely replacing the used filter cartridge with a new one. [68] While one preferred embodiment of the invention has been described hereinabove, the present invention is not limited thereto. It is to be understood that various changes and modifications may be made without departing from the scope of the invention defined in the claims.

Industrial Applicability [69] The gas mask of the present invention can find its application not only in the general industrial or public areas but also in the radioactively contaminated areas inclusive of nuclear power plants.