Concrete finishing machine having counterbalanced blade pitch adjustment apparatus
US4673311A · kind A · utility
Inventor
Key dates
| Filing date | Jul 2, 1985 |
| Grant date | Jun 16, 1987 |
| Priority date | — |
| Expiry date | Jul 2, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/2158
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A concrete finishing machine having a rotatable trowel blade assembly and a mechanism for controllably adjusting the pitch of the trowel blades relative to a wet concrete surface on which the blades rest. Manual pivoting of a control lever controllably adjusts the trowel blade pitch and, in doing so, automatically increases or decreases the amount of blade surface contacting the concrete surface, and correspondingly lowers or raises the machine relative to the surface. The contacting blade surface supports the machine's entire weight. A special counterbalancing apparatus that includes, for example, a compressed coil spring, biases the control lever so as to compensate for the machine's weight and permits an operator to adjust the blade pitch with substantially less force than otherwise would be required.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.