US5940927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Autonomous surface cleaning apparatus
Assignee: Electrolux AB
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Filing: 1997-04-29
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Granted: 1999-08-24
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Expires: 2017-04-29
Abstract
Abstract An autonomous device is adapted to automatically move on a work surface removing dirt, such as gravel, sand, dust particles and the like, from said work surface. The device comprises a chassis provided with wheels and with a brush roller rotated by a drive motor during said movement for the purpose of brushing up the dirt towards a suction duct wherefrom, by means of a suction air stream, the dirt is conveyed to a dust container. An electronic control device is provided for the control of the drive motor of the brush roller. If the movement of the brush roller is blocked or obstructed to a predetermined extent the control device is arranged to stop the brush roller motor and then transitorily activate the motor in the opposite direction and, finally, after another stop, to reconnect the brush roller motor to operate in the original direction of rotation.
Inventors
- 👤 Anders Haegermarck
- 👤 Bjorn Riise
- 👤 Jarl Hulden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:11
CPC Classifications
A; A47; A47L; A47L9/00; A47L9/02; A47L9/04; A47L9/0405; A47L9/0411; A47L5/00; A47L5/12; A47L5/22; A47L5/28; A47L5/30; A47L9/28; A47L9/2805; A47L9/2831; A47L9/2836; A47L9/2847; A47L9/2852; A47L9/2894; A47L2201/00; A47L2201/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
165 words
An autonomous device (10) adapted to automatically move on a work surface (11) removing dirt, such as gravel, sand, dust particles and the like, from said work surface, said device (10) comprising a chassis (12) provided with wheels and with a brush roller (20) rotated by a brush roller motor (22) during said movement for the purpose of brushing up the dirt towards a suction duct (23) wherefrom, by means of a suction air stream, the dirt is conveyed to a dust container (24), an electronic control device (25) being provided for the control of the drive motor (22) of the brush roller, characterized in that if the movement of the brush roller (20) is blocked or obstructed to a predetermined extent the control device (25) is arranged to stop the brush roller motor (22) and then transitorily activate the brush roller motor (22) in the opposite direction and, finally, to reconnect the brush roller motor (22) to operate in the original direction of rotation.
Claim 2
Dependent Claim
165 words
An autonomous device (10) adapted to automatically move on a work surface (11) removing dirt, such as gravel, sand, dust particles and the like, from said work surface, said device (10) comprising a chassis (12) provided with wheels and with a brush roller (20) rotated by a brush roller motor (22) during said movement for the purpose of brushing up the dirt towards a suction duct (23) wherefrom, by means of a suction air stream, the dirt is conveyed to a dust container (24), an electronic control device (25) being provided for the control of the drive motor (22) of the brush roller, characterized in that if the movement of the brush roller (20) is blocked or obstructed to a predetermined extent the control device (25) is arranged to stop the brush roller motor (22) and then transitorily activate the brush roller motor (22) in the opposite direction and, finally, to reconnect the brush roller motor (22) to operate in the original direction of rotation.
Claim 3
Dependent Claim
48 words
An autonomous device according to claim 1, characterized in that the control device (25) is arranged to measure, at a predetermined periodicity, the current through the brush roller motor (22) and to order backward drive of the brush roller motor if the motor current exceeds a predetermined limit.
Claim 4
Dependent Claim
41 words
An autonomous device according to claim 2, characterized in that the control device (25) is arranged to measure the motor current also during the backward drive and to stop the brush roller motor (22) if the motor current limit is exceeded.
Claim 5
Dependent Claim
40 words
An autonomous device according to claim 1, characterized in that the control device (25) is arranged to operate the brush roller motor (22) at a rated speed lower than the maximum speed and to keep the rated speed almost constant.
Claim 6
Dependent Claim
40 words
An autonomous device according to claim 4, characterized in that the brush roller motor (22) is a DC motor and the control device (25) is arranged to drive the brush roller motor (22) with a voltage that is pulse-width modulated.
Claim 7
Dependent Claim
58 words
An autonomous device according to claim 5, characterized in that the control device (25) is arranged to transitorily, at a predetermined periodicity, disconnect the drive voltage, the control device (25) having an input on which the EMF generated by the motor (22) during the corresponding time slot is applied for the determination of the speed of the motor.
Claim 8
Dependent Claim
51 words
An autonomous device according to any of the preceding claims, characterized in that the normal direction of rotation of the brush roller (20) is opposite to that of the drive wheels (14, 15) of the device when the device (10) is moving on the work surface (11) and cleaning takes place.
Claim 9
Dependent Claim
18 words
An autonomous device according to claim 1, characterized in that the electronic control device (25) is a microcomputer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-08-23 | 2003-02-22 | 2003-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-23 | 2007-02-22 | 2007-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-23 | 2011-02-22 | 2011-08-24 | $7700.00 | Window Closed / Lapsed |