# US 4,399,378 A · Filter for cooling air stream of electric commutator motor for household device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,399,378 A - Document ID: US4399378A - Status: Granted - Kind: A - Application number: 06/351,738 - Filed: 1982-02-24 - Granted: 1983-08-16 - Earliest claimed: 1981-03-02 - Assignees: Vorwerk & Co. Interholding GmbH - Inventors: Heinz-Gerhard Krumm; Horst Neugart - Web page: https://patentgrep.com/patent/US4399378A ## CPC - H02K 9/26: Structural association of machines with devices for cleaning or drying cooling medium, e.g. with filters - A47L 9/12: Dry filters - B03C 3/28: Plant or installations without electricity supply, e.g. using electrets - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - A47L: DOMESTIC WASHING OR CLEANING (brushes A46B; cleaning quantities of bottles or of other hollow articles of one kind B08B9/00; laundry D06F); SUCTION CLEANERS IN GENERAL (cleaning in general B08) - B03C: MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS (separating isotopes B01D59/00; combinations of magnetic or electrostatic separation with separation of solids by other means B03B, B07B) ## Abstract A filter for a cooling air stream of an electric commutator motor for a household device has a passage into which a cooling air stream flows after passing an electric commutator motor, and a filtering member composed of an electrostatically charged material which coats the passage partially or completely. ## Claims ### Claim 1 A filter for a cooling air stream of an electric commutator motor for a household device, comprising means forming a passage into which a cooling air stream flows in a predetermined direction after passing an electric commutator motor; and a filtering member composed of an electrostatically charged material which coats at least a portion of said passage, said electrostatically charged material having a section which extends substantially transverse to said direction, so that the cooling air flow impinges against said section. ### Claim 2 A filter for a cooling air stream of an electric commutator for a household device, comprising means forming a passage into which a cooling air stream flows in a predetermined direction after passing an electric commutator motor; and a filtering member composed of an electrostatically charged material which coats at least a portion of said passage, said electrostatically charged material having a section extending in said direction, so that cooling air stream flows substantially along said section, said electrostatically charged material also having a further section which extends substantially transverse to said direction, so that the cooling air stream not only flows along said first-mentioned section, but also impinges against said further section. ### Claim 3 A filter for a cooling air stream of an electric commutator motor for a household device, comprising means forming a passage into which a cooling air stream flows after passing an electric commutator motor; and a filtering member composed of an electrostatically charged material which coats at least a portion of said passage, said passage being substantially closed so that the cooling air stream, upon passing said electrostatically charged material, again circulates in said passage past the electric commutator motor. ### Claim 4 (depends on 1) A filter as defined in claim 1, wherein said filtering member is composed of an electrostatically charged material which completely coats said passage. ### Claim 5 (depends on 1) A filter as defined in claim 1; and further comprising holding means arranged to hold said filtering member of an electrostatically charged material, said holding means including a holding member which is insertable in and withdrawable from said passage together with said filtering member. ### Claim 6 (depends on 1) A filter as defined in claim 1, wherein said filtering member is composed of an electrostatically charged fibrous material. ### Claim 7 (depends on 1) A filter as defined in claim 1, wherein said passage forming means includes a wall, said electrostatically charged material which forms said filtering member coating at least a portion of said wall of said passage. ### Claim 8 (depends on 3) A filter as defined in claim 3, wherein the cooling air stream flows through said passage in a predetermined direction, said electrostatically charged material having a section extending in said direction, so that cooling air stream flows substantially along said section. ### Claim 9 (depends on 8) A filter as defined in claim 8, wherein said electrostatically charged material has a second such section also extending in said direction and spaced from said first-mentioned section, so that the cooling air stream flows between said sections. ### Claim 10 (depends on 3) A filter as defined in claim 3, wherein the cooling air stream flows through said passage in a predetermined direction, said electrostatically charged material having a section which extends substantially transverse to said direction, so that the cooling air flow impinges against said section. ### Claim 11 (depends on 8) A filter as defined in claim 8, wherein said electrostatically charged material has a further section which extends substantially transverse to said direction, so that the cooling air stream not only flows along said first-mentioned section, but also impinges against said further section. ### Claim 12 (depends on 1) A filter as defined in claim 1, wherein said passage is outwardly open so that the cooling air stream leaves said passages upon passing said electrostatically charged material. ### Claim 13 (depends on 1) A filter as defined in claim 1, wherein said passage is substantially closed so that the cooling air stream, upon passing said electrostatically charged material, again circulates in said passage past the electric commutator motor.