Light weight, fast steering riding trowel
US5108220A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1990 |
| Grant date | Apr 28, 1992 |
| Priority date | — |
| Expiry date | Jul 13, 2010 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04F21/247
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A compact, lightweight riding trowel for finishing concrete of enhanced maneuverability. A rigid frame is supported above the concrete by a pair of downwardly projecting synchronized rotors, each of which revolves multiple blades frictionally contacting the surface. Lights attached to frame corners provide illumination. The operator manually steers with a pair of primary control levers which tilt the rotors to generate steering forces. The pitch of each rotor blade is controlled manually or electrically, and a cable-driven clutch fork system is activated to vary pitch between minimum and maximum. Each of the tiltable rotor assemblies is driven by gear boxes coupled to the motor through a flexible disk drive shaft. Each gear box is mounted to the frame underside by a pivot steering box. Parallel lever arms extending beneath the frame in a direction generally perpendicular to the biaxial plane defined by the rotors are deflected by the primary control levers. Each activates elongated torque rods coupled to the gearboxes and tilts the rotors in a plane parallel with the biaxial plane. The torque rods are generally aligned, and for leverage they are braced by a gusset and offset from t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.