# US 7,406,742 B2 · Vacuum device/blower > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,406,742 B2 - Document ID: US7406742B2 - Status: Granted - Kind: B2 - Application number: 11/356,651 - Filed: 2006-02-17 - Published: 2006-08-24 - Granted: 2008-08-05 - Earliest claimed: 2005-02-19 - Assignees: Andreas Stihl AG & Co. KG - Inventors: Steffen Joos; Uwe Gaese - Web page: https://patentgrep.com/patent/US7406742B2 ## CPC - A47L 5/14: cleaning by blowing-off, also combined with suction cleaning - A01G 20/47: Vacuum or blower devices - A47L 9/2842: {Suction motors or blowers} - A47L 9/2889: {Safety or protection devices or systems, e.g. for prevention of motor over-heating or for protection of the user} - F04D 27/008: {Stop safety or alarm devices, e.g. stop-and-go control; Disposition of check-valves} - 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) - A01G: HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING (picking of fruits, vegetables, hops or the like A01D46/00; propagating unicellular algae C12N1/12) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract An apparatus comprising a blower fan, a motor for driving the blower fan, a blower tube for conveying an air stream from the blower fan, and a potential compensation device that is electrically connected with the motor. The potential compensation device includes a charge compensation element having a free end that projects in an exposed manner into the air stream. ## Claims ### Claim 1 An apparatus comprising: a blower fan, a motor for driving the blower fan, wherein the motor is a combustion engine, a blower tube for conveying an air stream from said blower fan, and a potential compensation device that is electrically connected with said motor, wherein said potential compensation device includes a charge compensation element, and wherein said charge compensation element has a free end that projects in an exposed manner into said air stream at a position that is spaced from said blower tube. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein said free end of said charge compensation element is disposed in said air stream within said blower tube. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein said charge compensation element is disposed at least approximately in the region of a free end of said blower tube, wherein said potential compensation device further includes a potential compensation conductor, and wherein said charge compensation element is electrically connected with said motor via said potential compensation conductor. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein at least said free end of said charge compensation element projects out of said free end of said blower tube. ### Claim 5 (depends on 1) The apparatus according to claim 1, wherein said charge compensation element is in the form of a flexible wire. ### Claim 6 (depends on 5) The apparatus according to claim 5, wherein said wire is a bare, stainless steel wire. ### Claim 7 (depends on 5) The apparatus according to claim 5, wherein said charge compensation element is formed by a plurality of wires that are grouped together in a broom-like manner, and wherein each of said wires has a free end. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein said wires that are grouped together in a broom-like manner form an electrically conductive spider having legs that extends radially outwardly in a ray-shaped manner, relative to a longitudinal axis of said blower tube. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein said legs are disposed in a cone-shaped manner. ### Claim 10 (depends on 9) The apparatus according to claim 9, wherein said cone shape of said legs has a half cone opening angle of a minimum of approximately 15° and a maximum of approximately 80°. ### Claim 11 (depends on 7) The apparatus according to claim 7, wherein said wires that are grouped together in a broom-like manner are formed by individual strands of an untwisted steel wire. ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein said steel wire is a potential compensation conductor of said potential compensation device. ### Claim 13 (depends on 1) The apparatus according to claim 1, wherein a positioning ring is disposed in said blower tube, and wherein said charge compensation element is positioned by means of said positioning ring. ### Claim 14 (depends on 13) The apparatus according to claim 13, wherein said positioning ring is provided with at least one radially inwardly projecting positioning arm, and wherein said positioning arm is provided with a snap clamp for a potential compensation conductor of said potential compensation device. ### Claim 15 (depends on 1) The apparatus according to claim 1, wherein said potential compensation device further includes a potential compensation conductor, and wherein at least a portion of said potential compensation conductor extends on the inside of said blower tube. ### Claim 16 An apparatus comprising: a blower fan, a motor for driving the blower fan, a blower tube for conveying an air stream from said blower fan, and a potential compensation device that is electrically connected with said motor, wherein said potential compensation device includes a charge compensation element, and wherein said charge compensation element has a free end that projects in an exposed manner into said air stream, wherein said potential compensation device further includes a potential compensation conductor, and wherein at least a portion of said potential compensation conductor extends on the inside of said blower tube, and wherein at least a portion of said potential compensation conductor is formed by a spring wire that in the region of a free end thereof is bent to form at least one support location that is retained in said blower tube. ### Claim 17 (depends on 16) The apparatus according to claim 16, wherein said spring wire is provided with two support locations that are axially offset relative to one another. ### Claim 18 An apparatus comprising: a blower fan, a motor for driving the blower fan, a blower tube for conveying an air stream from said blower fan, and a potential compensation device that is electrically connected with said motor, wherein said potential compensation device includes a charge compensation element, and wherein said charge compensation element has a free end that projects in an exposed manner into said air stream, wherein said potential compensation device furthermore includes a potential compensation conductor, and wherein at least a portion of said potential compensation conductor is integrated into a wall of said blower tube. ### Claim 19 An apparatus comprising; a blower fan, a motor for driving the blower fan, a blower tube for conveying an air stream from said blower fan, and a potential compensation device that is electrically connected with said motor, wherein said potential compensation device includes a charge compensation element, and wherein said charge compensation element has a free end that projects in an exposed manner into said air stream, wherein said potential compensation device furthermore includes a potential compensation conductor, and wherein at least a portion of said potential compensation conductor extends on an outer side of said blower tube.