Sheet suction device, sheet conveyor, printer, and suction area switching device

Patent metadata

Field	Value
Publication number	US-2021237994-A1
Application number	US-202117148662-A
Country	US
Kind code	A1
Filing date	Jan 14, 2021
Priority date	Jan 31, 2020
Publication date	Aug 5, 2021
Grant date	—

Abstract

A sheet suction device includes a sheet bearer having a plurality of suction holes on a plurality of bearing areas, a rotational portion having a plurality of holes that is connectable to the plurality of suction holes, a suction unit configured to suck air via the plurality of holes of the rotational portion. The sheet bearer bears a plurality of sheets on the plurality of bearing areas of the circumferential surface of the sheet bearer and rotates. The rotational portion rotates in a same cycle of the sheet bearer. The sheet suction device further includes a switching unit that switches combinations of whether or not to suck the air among the plurality of bearing areas of the sheet bearer according to a phase of rotation of the sheet bearer or the rotational portion.

First claim

What is claimed is:

1 . A sheet suction device comprising:
a sheet bearer configured to bear a plurality of sheets on a plurality of bearing areas of a circumferential surface of the sheet bearer and rotate, the sheet bearer having a plurality of suction holes on the plurality of bearing areas; a rotational portion configured to rotate in a same cycle of the sheet bearer, the rotational portion having a plurality of holes that are connectable to the plurality of suction holes; a suction unit configured to suck air via the plurality of holes of the rotational portion; and a switching unit configured to switch combinations of whether or not to suck the air among the plurality of bearing areas of the sheet bearer according to a phase of rotation of one of the sheet bearer and the rotational portion.

2 . The sheet suction device according to claim 1 ,
wherein the switching unit includes:
a stationary portion having a plurality of grooves divided in a circumferential direction of the stationary portion, the plurality of grooves configured to switch connection between the suction unit and the plurality of holes of the rotational portion; and
a valve configured to open and close between the stationary portion and the suction unit.

3 . The sheet suction device according to claim 2 ,
wherein the stationary portion has a plurality of rows of the plurality of grooves in a radial direction of the stationary portion.

4 . The sheet suction device according to claim 3 ,
wherein the valve includes a common valve that is common to grooves belonging to different rows of the plurality of rows.

5 . The sheet suction device according to claim 1 ,
wherein the switching unit is configured to switch whether or not to suck the air in the plurality of bearing areas of the sheet bearer in units of each of the plurality of sheets.

6 . The sheet suction device according to claim 1 ,
wherein the rotational portion includes:
a first member having grooves arranged in a circumferential direction of the rotational portion, the grooves configured to communicate with the suction unit; and
a second member having the plurality of holes arranged in the circumferential direction,
wherein, when the first member rotates with respect to the second member, the number of holes communicating with the grooves among the plurality of holes is changed to change the number of the plurality of suction holes communicating with the suction unit.

7 . The sheet suction device according to claim 6 ,
wherein the plurality of suction holes is arranged in a circumferential direction of the sheet bearer, and wherein, when the first member rotates, the number of the plurality of suction holes communicating with the suction unit is changed in the circumferential direction.

8 . The sheet suction device according to claim 6 ,
wherein the plurality of suction holes is arranged in an axial direction of the sheet bearer, and wherein, when the first member rotates, the number of the plurality of suction holes communicating with the suction unit is changed in the axial direction.

9 . A sheet conveyor comprising:
the sheet suction device according to claim 1 , wherein the sheet bearer is configured to rotate to convey the plurality of sheets.

10 . A printer comprising:
the sheet conveyor according to claim 9 ; and an image forming unit configured to form an image on the plurality of sheets.

11 . A suction area switching device between a plurality of suction holes on a plurality of bearing areas of a circumferential surface of a sheet bearer to bear a sheet on the circumferential surface and a suction unit to suck air through the plurality of suction holes, the suction area switching device comprising:
a rotational portion configured to rotate in a same cycle of the sheet bearer, the rotational portion having a plurality of holes that is connectable to the plurality of suction holes; and a switching unit configured to switch combinations of whether or not to suck the air among the plurality of bearing areas of the sheet bearer according to a phase of rotation of one of the sheet bearer and the rotational portion.

Assignees

• Miyagawa Hiroaki
• Ricoh Co Ltd

Inventors

• Miyagawa Hiroaki

Classifications

• B65H5/226

  by suction rollers · CPC title

• B65H2406/3622

  adjusting or controlling distribution of vacuum in the transport direction · CPC title

• B65H2406/362

  adjusting or controlling distribution of vacuum transversally to the transport direction, e.g. according to the width of material · CPC title

• B65H2406/3612

  involving a shoe in sliding contact with flanges of a rotating element · CPC title

• B65H2406/361

  distributing vacuum from stationary element to movable element · CPC title