Surface finishing machine with rotatable guard
US6019545A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1998 |
| Grant date | Feb 1, 2000 |
| Priority date | — |
| Expiry date | Dec 7, 2018 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04F21/248
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A motorized finishing machine has a rotatable guard system enabling it to finish concrete surfaces next to walls, posts, conduits, or other obstacles. Deployed as a concrete trowel, the machine comprises an internal combustion motor that powers a gearbox to revolve a downwardly projecting rotor. Numerous radially spaced-apart finishing blades controlled by the rotor frictionally contact the concrete surface being treated. A protective guard, which circumscribes the rotor, is rotatably suspended by a plurality of rollers. The guard, which is shaped somewhat like a truncated cone, comprises an inner ring coaxially secured above a larger diameter, outer ring. Radially spaced apart spokes extend between the upper and lower rings and brace the guard. The bearing-equipped rollers mounted by radially, spaced-apart arms have upper and lower flanges. The inner guard ring is captivated between the rollers, and it is vertically constrained between the roller flanges. When the guard contacts an obstacle it may freely rotate, enabling the power trowel to approach otherwise-unreachable surface regions without wobbling or rocking.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.