Sheet conveyor single-handed parting engagement mechanism

In an image reproducing apparatus sheet conveyance system, a sheet conveying unit comprising:

• a unit main frame installed in the image forming apparatus by means enabling said unit main frame to be withdrawable transverse to a direction of sheet conveyance through the image forming apparatus;
• a sheet storing section provided in said unit main frame;
• a lower conveying section disposed above the sheet storing section, said lower conveying section including a lower conveying guide, one end of said lower conveying guide being pivotably supported on said unit main frame, and said lower conveying section including a lower conveying element circulatingly supported on said lower conveying guide;
• an upper conveying section disposed above the lower conveying section, said upper conveying section including an upper conveying guide, one end of said upper conveying guide being pivotably supported on said unit main frame, and said upper conveying section including an upper conveying element circulatingly supported on said upper conveying guide, the upper and lower conveying elements operating in tandem for conveying sheets to said sheet storing sections;
• and
• a lock mechanism including a first linkage for enabling said upper conveying element to be locked in a predetermined open position wherein said upper conveying element is opened out above said sheet storing section;
• and
• a support mechanism including a second linkage for supporting said lower conveying element such that wherein said upper conveying element is locked in said open position by said lock mechanism, said lower conveying element is opened out above said sheet storing section, parted by predetermined clearances respectively from said upper conveying element and said sheet storing section.