Sheet feed tray and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorHisashi Kawamoto
Life of this patent
Estimating the term…
Abstract
A sheet feeding tray includes a frame member, and freely upwardly swingable plural bottom plates arranged on the frame member side by side perpendicular to a sheet feeding direction. The bottom plates cooperatively support a stack of envelope recording mediums. A lifting device having plural curvature sections is provided. The plural curvature sections are respectively arranged below the bottom plates to scuff and lift the lower surface of the plural bottom plates at a section downstream of the sheet feeding direction. The plural curvature sections each include a different outline in accordance with a difference of a decreasing amount of a thickness of the stack during sheet feeding. The different outlines enable the topmost surface of the stack to be almost horizontal.
Claims8
A sheet feeding tray, comprising:
- a frame member;
- at least two freely upwardly swingable bottom plates arranged on the frame member side by side perpendicular to a sheet feeding direction, said bottom plates cooperatively supporting a stack of envelope recording mediums;
- and
- a lifting device having at least two curvature sections respectively arranged below the bottom plates and configured to scuff and lift the lower surface of the at least two bottom plates at a section downstream of a trailing end of the at least two bottom plates in the sheet feeding direction;
- wherein said at least two curvature sections each includes a different outline in accordance with a difference of a decreasing amount of a thickness of the stack during sheet feeding, said different outlines enabling the topmost surface of the stack to be almost horizontal at leading ends of the bottom plates, and
- wherein each of the at least two bottom plates includes one of a concave and convex section and a hole engageable with the lifting device at the upstream end in the sheet feed direction.
An image forming apparatus including a sheet feed tray, said sheet feed tray comprising:
- a frame member;
- at least two freely upwardly swingable bottom plates arranged on the frame member side by side perpendicular to a sheet feeding direction, said bottom plates cooperatively supporting a stack of envelope recording mediums;
- and
- a lifting device having at least two curvature sections respectively arranged below the bottom plates and configured to scuff and lift the lower surface of the at least two bottom plates at a section downstream of a trailing end of the at least two bottom plates in the sheet feeding direction;
- wherein said at least two curvature sections each includes a different outline in accordance with a difference of a decreasing amount of a thickness of the stack during sheet feeding, said different outlines enabling the topmost surface of the stack to be almost horizontal at leading ends of the bottom plates, and
- wherein each of the at least two bottom plates includes one of a concave and convex section and a hole engageable with the lifting device at the upstream end in the sheet feed direction.
Dependencies are inferred from the claim text.