US 6,126,161 AGranted

Sheet feeder having improved sheet separation regardless of rigidity and size of sheet

AssigneeBrother Kogyo Kabushiki Kaisha

InventorHiroyuki Kato

Life of this patent

Estimating the term…

Loading patent…

Abstract

A sheet feeder providing accurate separation of an uppermost sheet from remaining sheets of a sheet stack stored in a hopper regardless of a size and rigidity of the sheets. The sheet feeder includes a sheet feed roller positioned in confrontation with the hopper for feeding the sheet in a sheet feeding direction. A wall of a frame confronts an outlet end portion of the hopper. The wall is provided with a slanted surface sloping toward the sheet feeding direction, and a stop member protrudable from or retractable into the slanted surface. A recessed portion is open to the slanted surface, and the stop member can be assembled to the recessed portion from an upper open side of the recessed portion. A pair of opposing side walls providing therebetween an upper open space are provided. A rotation shaft of the sheet feed roller can be assembled to the pair of side walls from the upper open space.

Claims18

Dependent claims

A sheet feeder for feeding each one of cut sheets in a sheet feeding direction comprising:

a frame on which a sheet feed passage is defined;
a hopper supported on the frame and housing therein a stack of sheets, the frame having a sheet receiving portion in contact with each leading edge of the sheets, the frame also forming a recessed portion at a position adjacent the sheet receiving portion, the recessed portion having an upper opening open toward the sheet feed passage, the frame including a pair of side walls defining an upper open space therebetween, the recessed portion and the sheet receiving portion being positioned in the upper open space;
a sheet feed mechanism having at least one sheet feed roller disposed in contact with an uppermost sheet of the sheet stack for feeding the uppermost sheet in the sheet feeding direction;
a stop member positioned in the recessed portion and pivotally movably supported by the frame between a protruding position protruding into the sheet feed passage and a retracted position retracted from the sheet feed passage, the stop member being assembled to the frame through the upper opening of the recessed portion;
and
a biasing member connected to the stop member that urges the stop member to its protruding position, the biasing member providing a biasing force dependent on the rigidity of the sheet that controls a protruding amount of the protruding position to create a bend in a leading edge of the sheet that increases when sheet rigidity decreases so as to ensure sheet separation.

3 more elements

An image forming device for forming an image on a cut sheet comprising:

a frame on which a sheet feed passage is defined;
a sheet feeder for feeding each one of cut sheets in a sheet feeding direction;
a printing mechanism having a print head that ejects ink toward the cut sheet;
and
a conveyer mechanism that conveys each one of the cut sheets fed by the sheet feeder to the printing mechanism, wherein the sheet feeder includes:
a hopper supported on the frame and housing therein a stack of sheets, the frame having a sheet receiving portion in contact with each leading edge of the sheets, the frame also forming a recessed portion at a position adjacent the sheet receiving portion, the recessed portion having an upper opening open toward the sheet feed passage;
a sheet feed mechanism having at least one sheet feed roller disposed in contact with an uppermost sheet of the sheet stack for feeding the uppermost sheet of the sheet stack for feeding the uppermost sheet in the sheet feeding direction;
a stop member positioned in the recessed portion and pivotally movably supported by the frame between a protruding position protruding into the sheet feed passage and a retracted position retracted from the sheet feed passage, the stop member being assembled to the frame through the upper opening of the recessed portion;
and
a biasing member connected to the stop member that urges the stop member to its protruding position, the biasing member providing a biasing force dependent on the rigidity of the sheet.

7 more elements

Dependencies are inferred from the claim text.