Clamp for fastening concrete rebar intersections

摘要

A structure for clamping two rods mutually transverse to one another is described. An upwardly open seating surface has a longitudinal direction for rotationally vertically receiving a first rod in the longitudinal direction. A pair of side opening rod retainers are supported above and on opposite sides of the upwardly open longitudinal seating surface. The side openings of the retainers open in opposite directions for rotationally laterally receiving opposite sides of a second rod along a direction transverse to the longitudinal direction. The retainers include top portions spaced from the lower seating surface a distance effective to cause a rod rotationally laterally received in the side openings to exert a compressive force against a rod rotationally vertically received on the lower seating surface, thereby clamping the rods mutually transversely to each other. The clamping structure may be rotated into the intersection to vertically receive the first rod in the longitudinal seat and to laterally receive opposite sides of the second rod under the top retainer portions to press the second rod forcibly against the first rod in the longitudinal seat. Using the clamping structure in the form of a chair, a mat is formed using the chairs to transversely clamp a plurality of first and second rods at right angles, concrete is poured on the mat supported over a pour surface by the chairs, and a reinforced concrete slab is formed in which the mat is positioned at a predetermined position internally in the slab.