Concrete screed with angularly positionable rake guide

Abstract

A floating screed device includes: an elongated float, rigid and spaced-apart rods with the tops thereof defining a planar region having a planar bottom for floating on plastic concrete, a device coupled to the float to determine elevation thereof relative to a target elevation in the plastic concrete, and a support and adjustment (S / A) mechanism that moves the rods based on the elevation so-determined as the floating screed device is moved through a volume of the plastic concrete that is unfinished. In general, the rods are moved by the S / A mechanism such that the planar region defined by the rods rotates about an axis that is parallel to the rods and perpendicular to the longitudinal axis of the float.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS[0001]This patent application is co-pending with one related patent application entitled “CONCRETE SCREED WITH PIVOTING LEADING-EDGE BLADE FOR ANGULAR POSITIONING THEREOF”, Ser. No. 12 / 322,149, filed Jan. 29, 2009, by the same inventors and owned by the same assignee as this patent application.FIELD OF THE INVENTION[0002]The invention relates generally to screeding devices, and more particularly to a screed device having a leading edge rake guide that can pivot to an angular position with respect to a trailing float.BACKGROUND OF THE INVENTION[0003]Floating screeds are used to strike off concrete floors or other horizontal surfaces to their desired finished elevation. Conventional floating screeds have a heavy planar float with an elongated edge defining a blade. The blade forms the leading edge of the screed that cuts through a volume of plastic concrete as the screed is pulled therethrough. Excess concrete that builds up on the blade s...

AI Technical Summary

Benefits of technology

"The present invention provides a screed device that improves the process of producing smooth and level concrete surfaces at a desired elevation. It includes an elongated float and a device that determines elevation relative to a target elevation in the plastic concrete. The device also includes a plurality of rigid and spaced-apart rods with the tops thereof defining a planar region. The rods form the initial contact between the screed device and the plastic concrete that is to be struck. The rods are moved by the screed device so that the planar region defined by the rods rotates about an axis that is parallel to the rods and perpendicular to the longitudinal axis of the float. This results in a smoother and more level surface, and makes the concrete rake workers more efficient. Additionally, the invention provides a floating screed device that can take advantage of a reference elevation defined by adjacent already-struck-but-unhardened concrete without subjecting same to subsequent repair."

Problems solved by technology

Owing to the weight and density of unhardened (wet) concrete, it is necessary for the rake workers to prevent any substantial build up of wet concrete just ahead of the screed as the weight of such excess build up makes the screed operator's job extremely difficult.

However, in trying to provide just enough excess concrete, the rake worker often gouges the un-struck concrete to a level that is below the desired finished height of the concrete.

Further, since the adjacent already-struck concrete is generally not yet hardened, this tilting action also can cause the floating screed to dig into the adjacent already-struck concrete and / or damage the edge of the adjacent already-struck concrete where it interfaces with the un-struck concrete thereby necessitating repair work.

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