Hydraulically controlled riding trowel
US5890833A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1997 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Jan 15, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04F21/247
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A high performance, multiple rotor riding trowel for finishing concrete and hydraulic controls therefor, enabling complete hand control to the operator of steering, propulsion, and blade pitch. A rigid trowel frame mounts two or more downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The rotor assemblies are tilted with double acting hydraulic cylinders to effectuate steering and control. Double acting hydraulic cylinders also control blade pitch. A joystick system enables the operator to hand control the trowel with minimal physical exertion. The joystick system activates solenoid control valves that in turn energize the various hydraulic cylinders that tilt the rotors and alter blade pitch. The rotor gearboxes are mounted to tiltable, pivot steering boxes secured to the frame within suitable mounting regions bounded by rigid frame elements. The rotor assembly blades contact plastic concrete to finish the surface while supporting the trowel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.