Patent ID: 6981819

Claim:
A concrete screed adapted to react automatically relative to a horizontal laser beam of fixed height above an uncured concrete surface, the screed comprising: a screed plate having first and second opposite ends, a leading edge, a trailing edge, and a flat bottom surface, the screed plate being elongated and having a longitudinal screed plate axis, the bottom surface of the screed plate resting on the uncured concrete surface; a vibrator mounted on the screed plate and being capable of actuation to cause vibration of the screed plate; a pivot member pivotally mounted to the screed plate for pivotal movement about a horizontal pivot axis extending in the same general direction of the longitudinal screed plate axis; a first handle and a second handle each having a first handle end connected to the pivot member, for pivotal movement about first and second axes, respectively, that are perpendicular to the horizontal pivot axis of the pivot member, the first and second handles each having a gripping end opposite from the first handle ends for gripping the handles; the first and second handles being attached to the pivot member in such a way that when the gripping ends of either or the first and second handles are held at a constant height they hold the pivot member against tilting movement about the horizontal pivot axis and the screed plate can tilt relative to the pivot member about the horizontal pivot axis; a laser beam detector on the screed plate for detecting whether or not the laser beam detector is above or below the horizontal laser beam; a tilt actuator electrically connected to the laser beam detector and being mechanically connected to both the screed plate and the pivot member; the tilt actuator causing the screed plate to tilt about the horizontal axis in a first direction in response to the laser beam detector sensing that the laser beam detector is below the horizontal laser beam and tilting the screed plate about the horizontal axis in a second direction opposite from the first direction in response to the laser beam detector sensing that the laser beam detector is above the horizontal laser beam.