Shutoff control methods for surface treating machines
US6042656A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 17, 1997 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Oct 17, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47L11/4077
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
An apparatus (200) is provided in a floor scrubber (10) for automatically shutting off the motor (60) which rotates an agitator (64) and the motor (96) of a vacuum assembly under various operating conditions of the floor scrubber (10). The current to the motors (60, 96) is detected by devices (204, 206) and monitored by a control circuit (202) controlling devices (208, 210 which interrupt operation of the motors (60, 96). In the preferred form, operation of the agitator (64) is interrupted when the current to the brush motor (60) is less than or equal to a threshold level indicating that the agitator (64) has been raised from the floor surface as the current to the brush motor (60) would be above the threshold level when the agitator (64) engages the floor surface. Operation of the vacuum assembly is interrupted when the current to the vacuum motor (96) drops to a fixed percentage over a period of time from normal operating levels indicating the path of the air in the vacuum assembly has been blocked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.