Patent ID: 6457902
Filing Date: 2002-10-01
Classification: E04G

Abstract:
A method of leveling a poured concrete slab comprising:(A) translating a truss screed over a top of a form containing poured concrete, the truss screed including (1) a frame; (2) at least one screed plate which rests on top of the form and which is supported on the frame, (3) an exciter shaft which is supported on the frame; (4) a shaft guard which covers the exciter shaft and which includes (a) sections of tubing that cover the exciter shaft, and (b) a plurality of joints that support the sections of tubing on the frame and that include a bearing supporting the exciter shaft on the frame; and (5) a torque transfer system; (B) as the truss screed is being translated over the form, driving the exciter shaft to rotate by operating the torque transfer system; (C) as a result of exciter shaft rotation, imparting a vibratory motion to the screed plate through the bearings; and (D) prior to step (A), permitting at least limited flexing movement of the frame and at least limited movement of the tubing sections relative to one another while adjusting the truss screed to vary an angular orientation of two adjacent screed sections relative to one another, wherein limited movement of the tubing sections is accommodated by permitting at least one of the joints to flex, wherein the step of permitting the joint to flex comprises distorting a resilient spring ring disposed between an end of one of the tubing sections the bearing supporting that end section.