Abstract: The object of this invention is to provide a reinforcing bar coupling used to easily, simply, quickly and mechanically butt-joint two reinforcing bars to each other for use in reinforced concrete construction. The reinforcing bar coupling consists of a cylindrical sleeve (2) axially receiving two reinforcing bars (1) through two inlets (20), with an uneven interior surface (22) formed in the sleeve (2) to correspond to the ribs (11) formed around the external surface of the bars (1). A plurality of wedges (4) are set in the gap between the bars (1) and the sleeve (2). The internal surface of the sleeve (2) and the external surface of the bars (1) with the wedges (4) are radially compressed to butt-joint the two bars (1) by the coupling.

Abstract: A beam scanning apparatus of an electrophotographic color printer having first and second light sources, and a deflecting unit including a driving source and first and second beam deflectors. The driving source has a rotation shaft and the first and second beam deflectors are coaxially installed on the rotation shaft and respectively deflect and scan beams of light emitted from the first and second light sources. First and second beam correcting units are arranged along the path of light between the deflecting unit and a photoreceptor and respectively correct the beams deflected by the first and second beam deflectors.