# US 11,305,299 B2 · Micro-bubble generator and shower head > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,305,299 B2 - Document ID: US11305299B2 - Status: Granted - Kind: B2 - Application number: 16/498,536 - Filed: 2017-04-05 - Published: 2020-01-30 - Granted: 2022-04-19 - Earliest claimed: 2017-04-05 - Assignees: Toshin Inc. - Applicants: Toshin Inc. - Inventors: Koichi Otoguro - Web page: https://patentgrep.com/patent/US11305299B2 ## CPC - B05B 1/18: Roses; Shower heads - A47K 3/28: Showers {or bathing douches} (combined with baths A47K3/20) - B01F 23/231: by bubbling (mixers with gas or liquid agitation, e.g. with air supply tubes B01F33/40) - B01F 23/235: for making foam - B01F 23/2373: for obtaining fine bubbles, i.e. bubbles with a size below 100 µm - B01F 25/3121: {with additional mixing means other than injector mixers, e.g. screens, baffles or rotating elements} - B01F 25/31232: {used simultaneously} - B01F 25/31243: {Eductor or eductor-type venturi, i.e. the main flow being injected through the venturi with high speed in the form of a jet} - B01F 25/31423: {with a plurality of perforations in the circumferential direction only and covering the whole circumference} - B01F 25/431: Straight mixing tubes with baffles or obstructions that do not cause substantial pressure drop; Baffles therefor - B01F 25/431971: {Mounted on the wall} - B01F 25/431974: {Support members, e.g. tubular collars, with projecting baffles fitted inside the mixing tube or adjacent to the inner wall} - E03C 1/084: Jet regulators with aerating means - B01F 23/237611: {Air} - B05B: SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES (spray-mixers with nozzles B01F25/72; processes for applying liquids or other fluent materials to surfaces by spraying B05D) - A47K: SANITARY EQUIPMENT; ACCESSORIES THEREFOR, e.g. TOILET ACCESSORIES - B01F: MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING (mixing paints B44D3/06) - E03C: DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER (not connected to either water-supply main or to waste pipe A47K; devices of the kind used in the ground E03B, E03F); SINKS ## Abstract One object is to generate, without the need for a motive power source and a high level of machining accuracy, micro-bubbles containing a large amount of fine air bubbles. Another object is to provide a micro-bubble generator that switches between micro-bubble water, which contains micro-bubbles, and foamed water containing a large amount of air and having a tender texture. The micro-bubble generator includes: a water passage that includes a smaller diameter portion and a larger diameter portion disposed on the downstream side of the smaller diameter portion; an air inlet disposed in the larger diameter portion and an elastic body disposed in the air inlet and configured to isolate the water passage from external air. The elastic body is compressible by negative pressure generated in the water passage, causing the external air to be sucked into the water passage through the air inlet and over the compressed elastic body. ## Claims ### Claim 1 A micro-bubble generator comprising: a water passage comprising: a smaller diameter portion; and a larger diameter portion disposed on a downstream side of the smaller diameter portion; an air inlet disposed in the larger diameter portion; and an elastic body disposed in the air inlet and configured to isolate the water passage from external air, wherein the elastic body is disposed on a wall surface of the air inlet such that the elastic body is in pressure contact with the wall surface, and wherein the elastic body is compressible by negative pressure generated in the water passage generating a gap between the elastic body and the wall surface and causing the external air to be sucked into the water passage through the gap in the air inlet. ### Claim 2 (depends on 1) The micro-bubble generator according to claim 1, wherein the negative pressure is generated in the larger diameter portion by high-speed water flowing in the smaller diameter portion of the water passage. ### Claim 3 (depends on 1) The micro-bubble generator according to claim 1, wherein the elastic body is in pressure contact with the wall surface of the air inlet at a predetermined compression ratio. ### Claim 4 (depends on 1) The micro-bubble generator according to claim 1, wherein the elastic body is compressible in a direction orthogonal to the wall surface of the air inlet. ### Claim 5 (depends on 1) The micro-bubble generator according to claim 1, wherein the smaller diameter portion comprises a plurality of smaller diameter portions disposed in the water passage. ### Claim 6 (depends on 1) The micro-bubble generator according to claim 1, wherein the air inlet comprises a first air inlet in which the elastic body is disposed, and a second air inlet having an opening connected to the water passage, and wherein the air inlet is switchable between the first air inlet and the second air inlet. ### Claim 7 A micro-bubble generator comprising: an inner case comprising: a water inlet hole; a water discharging hole; and an inner ventilation window disposed along a water passage disposed between the water inlet hole and the water discharging hole; and an outer case disposed on an outer side of the inner case and comprising an outer ventilation window connected to the inner ventilation window, wherein the outer case is configured to make a sliding movement with an outer circumference surface of the inner case, and comprises an elastic body disposed in the outer case, the elastic body being in pressure contact with the outer circumference surface of the inner case and configured to make a sliding movement along the outer circumference surface of the inner case, wherein when the outer case makes the sliding movement, a first air inlet and a second air inlet are switched to and from each other, wherein the first air inlet is formed when the inner ventilation window and the outer ventilation window are displaced from each other, generating a gap between the outer circumference surface of the inner case and the elastic body and connecting the water passage to external air through the gap, and wherein the second air inlet is formed when the outer ventilation window is aligned with the inner ventilation window, connecting the water passage to the external air. ### Claim 8 (depends on 7) A shower head comprising: the micro-bubble generator according to claim 7; a head case having a water inlet hole, a water discharging hole, and a water passage in which the micro-bubble generator is disposed; and a switching lever configured to switch between the first air inlet in which the elastic body is disposed and the second air inlet having an opening connected to the water passage of the micro-bubble generator. ### Claim 9 (depends on 8) The shower head according to claim 8, wherein the head case has an external air inlet disposed at least at one position in the head case, and wherein external air is guided into the first air inlet or the second air inlet through the external air inlet.