Vacuum cleaner having magnetic drive for agitator brush
US4099291A · kind A · utility
Inventor
Key dates
| Filing date | Jun 1, 1977 |
| Grant date | Jul 11, 1978 |
| Priority date | — |
| Expiry date | Jun 1, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K7/11
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
In accordance with the present invention, the agitator brush in the suction nozzle of an upright vacuum cleaner is positively driven by the high speed fan motor through reduction gearing, including a torque-limiting magnetic drive, which will disengage in the event the agitator brush is stalled or overloaded to thus prevent damage to the motor and conversely will limit the value of the torque transmitted to the agitator in order to minimize the damage done to whatever has stalled the brush. In some cases the value of the torque at which the magnetic drive is designed to disengage may be lower than that required to overcome the frictional resistance to turning of the agitator on the rug being cleaned plus the inertia load of the driven system during the rapid acceleration from start to full speed, which results if the motor is initially supplied with full line voltage. Hence, the invention includes means which may be employed in such cases for automatically reducing the rate of acceleration of the motor during starting, thus reducing the inertia load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.