Patent Number: 6,250,844

Title: Concrete finishing trowel with improved rotor assembly drive system

Abstract: A concrete finishing trowel has one or more driven rotor assemblies coupled to an engine or other power source of the machine by a novel torque transfer system including at least one flexible shaft and possibly including a variable speed ratio torque converter assembly. The flexible shaft, preferably comprising a flexible wound wire shaft, bends to accommodate tilting movement of the associated rotor assembly that occurs upon a steering operation, thereby eliminating the need for high-maintenance universal joints or other, less durable equipment. The torque converter assembly, preferably taking the form of a pair of variable speed clutches each having variable diameter sheaves, permits the speed and torque ratios of the drive system to change with increases in engine speed so that the same machine can be effectively used for both low speed/high torque floating operations and for high speed burning operations. Multi-application use is further facilitated by moving the blades axially along their support arms to permit the blades to operate in either an overlapping mode or a non-overlapping mode.

Inventors: Sartler; Ronald R. (West Bend, WI), Smith; Peter J. (Hartford, WI), Grant; Steven D. (Richfield, WI)

Assignee: Wacker Corporation

International Classification: E04F 21/24 (20060101); E04F 21/00 (20060101); E01C 019/22 ()

Expiration Date: 06/26/2018