Power trowel with counterbalanced trowel blade pitch adjust assembly
US5993109A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1997 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Jul 22, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04F21/248
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A power trowel incorporates a counterbalanced blade pitch adjust assembly that is relatively easy to manufacture and to install (and hence that can be retrofitted onto an existing power trowel machine) and that is easy to operate. The blade pitch adjust assembly includes 1) a blade pitch adjustment mechanism, 2) a pivotable control lever assembly that is coupled to the adjustment mechanism by a cable or other tension element, and 3) a counterbalancing mechanism such as a torsion spring. The counterbalancing mechanism imposes a force on the control lever assembly that is significantly lower than the resistive force imposed on the control lever assembly by the tension element to avoid potentially dangerous control lever snap-back and to provide the operator with a sense of feel as he or she adjusts blade pitch. A latch mechanism is incorporated into the system that releases automatically when the operator applies a pivotal force to the control lever assembly--thereby obviating the need to effect a secondary release operation. The orientation of the control lever assembly also can be adjusted to meet the needs of the operator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.