pparatus according to an embodiment of the present invention.FIGS. 2A and 2B are a plan view and an enlarged cross-sectional view, respectively, of a sheet conveying apparatus.FIG. 3 is a front view of the sheet conveying apparatus.FIG. 4 is a perspective view illustrating the operation of the sheet conveying apparatus.FIGS. 5A and 5B show other constructions of the sheet conveying apparatus.FIG.