# US 12,005,385 B2 · Stretcher of elastic material, air filter unit capable of controlling air permeability including same, and mask including the air filter unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,385 B2 - Document ID: US12005385B2 - Status: Granted - Kind: B2 - Application number: 17/267,871 - Filed: 2020-11-17 - Published: 2022-04-14 - Granted: 2024-06-11 - Earliest claimed: 2020-04-06 - Assignees: Seoul National University R&Db Foundation - Applicants: Seoul National University R&Db Foundation - Inventors: Seung Hwan Ko; Jaeho Shin; Seong Min Jeong; Jinmo Kim; Joonwha Choi - Web page: https://patentgrep.com/patent/US12005385B2 ## CPC - A62B 18/025: {Halfmasks (A62B23/02 takes precedence; surgical face masks A41D13/11)} - B01D 46/4227: {Manipulating filters or filter elements, e.g. handles or extracting tools} - A41D 13/11: Protective face masks, e.g. for surgical use, or for use in foul atmospheres (eye-masks A61F9/04 {; hoods affording protection against heat or harmful chemical agents A62B17/04}) - A61L 2/10: Ultraviolet [UV] radiation - A62B 23/025: {the filter having substantially the shape of a mask (surgical face masks A41D13/11)} - B01D 39/14: Other self-supporting filtering material {; Other filtering material (non-woven fabrics in general D04H3/00)} - B01D 46/0005: {Mounting of filtering elements within casings, housings or frames (B01D46/2422 takes precedence)} - B01D 46/0028: {provided with antibacterial or antifungal means} - B01D 46/10: Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces - B01D 46/543: {using membranes} - A61L 2202/11: Apparatus for generating biocidal substances, e.g. vaporisers, UV lamps - A62B 9/006: {Indicators or warning devices, e.g. of low pressure, contamination} - B01D 2279/40: for cleaning of environmental air, e.g. by filters installed on vehicles or on streets - A62B: DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING (valves specially adapted for medical use A61M39/00; life-saving devices, apparatus or methods specially adapted for use in water B63C9/00; divers' equipment B63C11/00; specially adopted for use with aircraft, e.g. parachutes, ejector seats, {B64D17/00, B64D25/10}; rescue devices peculiar to mining E21F11/00) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - A41D: OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) ## Abstract A mask according to an embodiment of the present disclosure may adjust permeability thereof by including and using an air filter unit which is capable of expanding or contracting, in at least one direction, a filter for filtering particles contained in air passing through the mask by pores. ## Claims ### Claim 1 A stretcher capable of expanding an elastic material located at a center thereof, the stretcher comprising: a variable part installed around the elastic material and configured to pull at least one side of the elastic material and expand the elastic material, wherein the variable part comprises: a first wall connected to the elastic material and having elasticity; a second wall constituting a hollow hole together with the first wall; a partition wall configured to partition the hollow hole into a first space and a second space; one or more connection holes formed in the partition wall so that air is able to move between the first space and the second space; and a sealing member installed in the first space and configured to seal the first space and the second space from an outside, wherein the first wall is extended toward the hollow hole as air escapes from the hollow hole, and the first wall expands the elastic material as the first wall is extended toward the hollow hole, and wherein at least a portion of the second space is formed by the first wall, the first wall is extended toward the second space by injection of air from the second space to the first space according to a movement of the sealing member in one direction, and the first wall expands the elastic material as the first wall is extended toward the second space. ### Claim 2 (depends on 1) The stretcher of claim 1, wherein the first wall is contracted in a reverse direction from the second space as air in the second space is introduced into the first space according to the movement of the sealing member in the reverse direction of the one direction, and as the first wall is contracted in the reverse direction from the second space, the elastic material is recovered to an original state while a force expanding the elastic material is lowered. ### Claim 3 (depends on 1) The stretcher of claim 1, wherein a lever connected to the sealing member is installed outside the variable part, and the movement of the sealing member is controlled by an operation of the lever. ### Claim 4 (depends on 1) The stretcher of claim 1, wherein the partition wall vertically or horizontally partitions the hollow hole. ### Claim 5 (depends on 1) The stretcher of claim 1, wherein as an entire outer circumference of the elastic material is connected to the first wall or an outer circumference of the elastic material is connected to the first wall at equal intervals, and as the first wall is extended toward the hollow hole, the elastic material is isotropically expanded. ### Claim 6 (depends on 1) The stretcher of claim 1, wherein the second wall is formed so that a movement thereof is restricted according to air injected into the hollow hole. ### Claim 7 (depends on 1) The stretcher of claim 1, wherein a fixing wall or a fixing frame for restricting a movement of the second wall due to air injected into the hollow hole is installed inside or outside the second wall. ### Claim 8 An air filter unit capable of adjusting permeability comprising: a filter configured to filter particles contained in passing air by pores and a stretcher capable of expanding or contracting the filter in at least one direction, wherein: the filter is formed of an elastic material and has pores, sizes of which vary according to an operation of the stretcher; the stretcher comprises: a membrane in which the filter is installed; and a variable part installed around the membrane and configured to pull at least one side of the membrane and expand the elastic material, wherein the variable part comprises: a first wall connected to the membrane and having elasticity; a second wall constituting a hollow hole together with the first wall; a partition wall configured to partition the hollow hole into a first space and a second space; one or more connection holes formed in the partition wall so that air is able to move between the first space and the second space; and a sealing member installed in the first space and configured to seal the first space and the second space from an outside, wherein the first wall is extended toward the hollow hole as air escapes from the hollow hole, the first wall expands the membrane as the first wall is extended toward the hollow hole, and the pores of the filter are expanded depending on an expansion of the membrane, and wherein at least a portion of the second space is formed by the first wall, the first wall is extended toward the second space by injection of air from the second space to the first space according to a movement of the sealing member in one direction, and the first wall expands the membrane as the first wall is extended toward the second space. ### Claim 9 (depends on 8) The air filter unit of claim 8, wherein the membrane comprises one or more holes which are formed in a central portion thereof and through which air passes. ### Claim 10 (depends on 8) The air filter unit of claim 8, wherein a central portion of the membrane is formed in a mesh shape, and the filter makes close contact with the mesh-shape portion. ### Claim 11 (depends on 8) The air filter unit of claim 8, further comprising: a lid installed on a front surface of the filter and spaced apart from the filter; and a lamp installed inside the lid and configured to irradiate the filter with ultraviolet. ### Claim 12 (depends on 8) The air filter unit of claim 8, wherein the first wall is contracted in a reverse direction from the second space as air in the second space is introduced into the first space according to the movement of the sealing member in the reverse direction of the one direction, and as the first wall is contracted in the reverse direction from the second space, the membrane is recovered to an original state while a force expanding the membrane is lowered. ### Claim 13 (depends on 8) The air filter unit of claim 8, wherein a lever connected to the sealing member is installed outside the variable part, and the movement of the sealing member is controlled by an operation of the lever. ### Claim 14 (depends on 8) The air filter unit of claim 8, wherein the partition wall vertically or horizontally partitions the hollow hole. ### Claim 15 (depends on 8) The air filter unit of claim 8, wherein as an entire outer circumference of the membrane is connected to the first wall or an outer circumference of the membrane is connected to the first wall at equal intervals, and as the first wall is extended toward the hollow hole, the membrane is isotropically expanded. ### Claim 16 A mask comprising: a mask body configured to cover the nose and mouth of a wearer; an air filter unit installed to the mask body; and a fixing member formed on both sides of the body and configured to fix the body to a face of the wearer, wherein: the air filter unit comprises a filter configured to filter particles contained in passing air by pores and a stretcher capable of expanding or contracting the filter in at least one direction, the filter, the filter is formed of an elastic material and has pores, sizes of which vary according to an operation of the stretcher, the stretcher comprises: a membrane in which the filter is installed; and a variable part installed around the membrane and configured to pull at least one side of the membrane and expand the elastic material, the variable part comprises: a first wall connected to the membrane and having elasticity; a second wall constituting a hollow hole together with the first wall; a partition wall configured to partition the hollow hole into a first space and a second space; one or more connection holes formed in the partition wall so that air is able to move between the first space and the second space; and a sealing member installed in the first space and configured to seal the first space and the second space from an outside, the first wall is extended toward the hollow hole as air escapes from the hollow hole, the first wall expands the membrane as the first wall is extended toward the hollow hole, and the pores of the filter are expanded depending on an expansion of the membrane, and at least a portion of the second space is formed by the first wall, the first wall is extended toward the second space by injection of air from the second space to the first space according to a movement of the sealing member in one direction, and the first wall expands the elastic material as the first wall is extended toward the second space. ### Claim 17 (depends on 16) The mask of claim 16, wherein the mask body has a permeability and is formed of a material capable of filtering particles. ### Claim 18 (depends on 16) The mask of claim 16, further comprising: a sensor configured to detect a state of peripheral air; and a pump configured to inject air into or absorb air from the hollow hole, whereinthe pump injects air into the hollow hole or absorbs air from the hollow hole according to the state of peripheral air, and increases or lowers permeability of the air filter unit.