# US 8,786,454 B2 · Air flow sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,454 B2 - Document ID: US8786454B2 - Status: Granted - Kind: B2 - Application number: 12/543,799 - Filed: 2009-08-19 - Published: 2010-02-25 - Granted: 2014-07-22 - Earliest claimed: 2008-08-25 - Assignees: World Magnetics Company - Applicants: John Siddall - Inventors: John Siddall - Web page: https://patentgrep.com/patent/US8786454B2 ## CPC - D06F 58/22: Lint collecting arrangements - D06F 58/50: Responding to irregular working conditions, e.g. malfunctioning of blowers - D06F 2103/00: Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers - D06F 2103/28: Air properties - D06F 2103/30: Pressure - D06F 2103/36: Flow or velocity - D06F 2105/58: Indications or alarms to the control system or to the user - D06F 2105/60: Audible signals - D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES ## Abstract A device for identifying the air flow condition within a clothes dryer having a lint filter, an exhaust passage, and a blower is disclosed. The device includes a sensor, an input having a first end connected to the sensor and a free second end, wherein the free second end is adapted to be disposed within the clothes dryer, upstream from a filter, and wherein the sensor detects a differential between an operating pressure at the free second end of input versus a reference pressure to thereby determine whether a sufficient vacuum is present within the clothes dryer, and an output that provides an output characteristic based on the differential, wherein the output characteristic changes from a first characteristic to a second characteristic when the differential surpasses a differential threshold. ## Claims ### Claim 1 A device for identifying an air flow condition within a plurality of clothes dryers, each having: a door, a lint filter and a blower, the device comprising: a housing containing a power supply; a sensor disposed within the housing; a tubular member having a first end connected to the sensor and a second end that extends beyond an outer surface of the housing, wherein the tubular member defines a passageway extending between the first end and the second end such that the first end is in fluid communication with atmosphere that surrounds the outer surface of the housing, wherein the tubular member is retractably connected to housing and sensor such that a majority portion of tubular member is contained within housing when the device is not being used and can be extended therefrom beyond the outer surface of the housing and into a working position, wherein the tubular member is a flexible plastic tube and is extendable through the door when arranged in a closed orientation without materially affecting the operation of the clothes dryer, wherein the second end of the tubular member is adapted to be disposed within the clothes dryer, upstream from a filter, and wherein the sensor detects a differential between an operating pressure at the free second end of the tubular member versus a reference pressure to thereby determine whether a sufficient vacuum is present within the clothes dryer; and an output that provides an output characteristic when the differential is less than a pre-determined differential threshold, wherein the output characteristic changes from a first characteristic to a second characteristic when the differential surpasses the pre-determined differential threshold, wherein the device is a handheld, portable device that can readily identify the flow condition in a plurality of clothes dryers. ### Claim 2 (depends on 1) The portable test device according to claim 1, further comprising: a housing, wherein the sensor is disposed within the housing, and wherein the tubular member is a tubular member and the second end of the tubular member extends outside of the housing. ### Claim 3 (depends on 2) The portable test device according to claim 2, wherein the tubular member is retractable such that second end of tubular member extends between a first operating position and a second non-operating position. ### Claim 4 (depends on 1) The portable test device according to claim 1, wherein the sensor includes a device selected from the group consisting of a transducer and a normally open pressure vacuum differential switch. ### Claim 5 (depends on 1) The portable test device according to claim 1, wherein the sensor includes two or more pressure vacuum differential switches to identify more than one vacuum conditions within the clothes dryer. ### Claim 6 (depends on 1) The portable test device according to claim 1, wherein the output includes one or more light emitting diodes. ### Claim 7 (depends on 6) The portable test device according to claim 6, wherein the output further includes an alarm that activates when the output characteristic is the second characteristic. ### Claim 8 (depends on 7) The portable test device according to claim 7, wherein the alarm is selected from the group consisting of a smoke alarm, a fire alarm, a carbon monoxide detector and any combination thereof. ### Claim 9 (depends on 7) The portable test device according to claim 7, wherein the alarm is communicatively attached to a receiver of a third party service provider. ### Claim 10 (depends on 1) The portable test device according to claim 1, wherein the reference pressure is the environmental pressure outside of the clothes dryer. ### Claim 11 A method comprising the steps of: providing a portable test device having an air flow sensor, a tubular member having a first end connected to the air flow sensor and a second end that extends beyond an outer surface of the housing, wherein the tubular member defines a passageway extending between the first end and the second end such that the first end is in fluid communication with atmosphere that surrounds the outer surface of the housing, wherein the tubular member is retractably connected to housing and sensor such that a majority portion of tubular member is contained within housing when the portable test device is not being used and can be extended therefrom beyond the outer surface of the housing and into a working position, wherein the tubular member is a flexible plastic tube; interfacing the portable test device with a working device having an exhaust passage, wherein the working device is a clothes dryer having: a door, a lint filter and a blower, wherein the interfacing step includes inserting the second end of the tubular member into a clothes drying area of the clothes dryer, upstream from the lint trap, the exhaust passage and the blower; closing the door of the clothes dryer such that the second end remains within the clothes drying area; activating the clothes dryer for arrangement in an on condition; comparing internal pressure within the clothes dryer against an environmental pressure outside of the clothes dryer to identify whether a sufficient vacuum is present within the clothes dryer; determining an output characteristic when the difference between the internal pressure and the environmental pressure is less than a pre-determined threshold; and providing the output characteristic, wherein the detection occurs without modification of the dryer, wherein the tubular member is adapted to extend through the door when arranged in a closed orientation without materially affecting the operation of the clothes dryer. ### Claim 12 (depends on 11) The method according to claim 11, wherein the output characteristic identifies an abnormal condition when the difference between the pressure outside of the clothes dryer and the pressure in the clothes drying area is at or substantially around a pre-defined threshold difference. ### Claim 13 (depends on 12) The method according to claim 12, wherein the output includes an alarm, and further comprising the steps of: activating the alarm when the output characteristic identifies an abnormal condition. ### Claim 14 (depends on 13) The method according to claim 13, wherein the step of activating an alarm further comprises the sub-step of: sounding an audible alarm. ### Claim 15 (depends on 13) The method according to claim 13, wherein the step of activating an alarm further comprises the sub-step of: sending a communication that signifies the output characteristic. ### Claim 16 (depends on 15) The method according to claim 15, wherein the communication is sent to a third party service provider. ### Claim 17 (depends on 15) The method according to claim 15, wherein the communication is sent to a consumer communication device. ### Claim 18 (depends on 11) The method of detecting an airflow condition in a clothes dryer according to claim 11, wherein the portable test device includes one or more light emitting diodes and wherein the output characteristic of a normal condition and the output characteristic of an abnormal condition are differentiated by an activation of the one or more light emitting diodes.