Control of torque in floor maintenance tools by drive motor load
US4757566A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1987 |
| Grant date | Jul 19, 1988 |
| Priority date | — |
| Expiry date | Jul 27, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE01H1/053
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
An automatic tool torque compensator for a surface maintenance machine such as a sweeper or scrubber includes an actuator for raising and lowering one or more rotatable surface maintenance tools and one or more electric or hydraulic motors for driving the tools. There is a circuit for sensing the current load in at least one of the electric motors, or the differential pressure in one or more of the hydraulic motors, and providing a signal representative thereof. There is a circuit for manually selecting a desired tool torque to be applied from a plurality of possible tool torques and for providing an electrical signal representative thereof. The electrical signal representative of the desired tool torque to be applied to the tools and the drive motor load current signal or the differential hydraulic pressure signal representative of actual tool torque applied to the tools are used to control the actuator for raising and lowering the surface maintenance tools. This automatically varies the pressure of the tools against the surface to maintain a desired torque in the tools at a nearly constant value even though the surface may vary in its resistance to the tools due to variations in …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.