US 5,031,002 AGranted

Suction-type sheet carrying mechanism applied to an image forming apparatus

AssigneeFujitsu Limited

InventorMasanori Yaguchi

Life of this patent

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Abstract

A suction type sheet carrying mechanism for a high speed image forming apparatus, in which a sheet is separated from an electrophotosensitive drum by air suction performed by mechanically combining fixed air suction holes of a hollow shaft and rotated air suction holes of belt pulleys. The sheet is stuck onto rotating endless belts and carried along a curved route by air suction performed by combining moving air holes of moving endless belts. High speed air flows through ditches provided on a belt guide board placed under the endless belts. The sheet is carried through a fixing unit under high temperature circumstances by rotating air suction metal rollers arranged perpendicular to the direction in which the sheet is carried. Fixed air suction holes in a hollow shaft and rotating air suction holes at ring-shaped ridges of a cylinder rotated around the hollow shaft of each air suction metal roller combine to form suction to hold the sheet.

Claims10

Dependent claims

A sheet carrying mechanism for carrying a recording sheet having a specified size in an image forming apparatus, from image transcription means for transcribing toner images on an image bearing member onto the recording sheet to image fixing means for fixing the toner images onto the recording sheet, said sheet carrying mechanism comprising:

air exhausting means for suctioning the recording sheet in the sheet carrying mechanism;
a plurality of rotatable endless belts for carrying the recording sheet after the recording sheet is suctioned to said endless belts;
and
sheet suction belt means for carrying the recording sheet along a curved sheet carrying route from the image transcription unit to the image fixing means, said sheet suction belt means comprising:
a plurality of first air suction holes on each one of said endless belts, arranged in a line along a center line of each of said endless belts, and being spaced by a first interval;
a curved belt guide board corresponding to the curved sheet carrying route, for moving said endless belts attaching to an upper surface of said curved belt guide board, said curved belt guide board having a plurality of ditches in an upper surface along respective center lines of said endless belts, each ditch being narrower than said endless belts in width and having a plurality of second air suction holes spaced by a second interval which is less than the first interval;
and
an air exhausting chamber, located under said curved belt guide board and connected to said air exhausting means, said second air suction holes opening therein.

5 more elements

A sheet suction roller mechanism for carrying a sheet, said sheet having a specified size suction roller mechanism comprising:

air exhausting means for suctioning the sheet to be carried;
a plurality of sheet suction rollers arranged perpendicular to a direction in which the sheet is carried, and spaced at intervals less than the size of half of the sheet in the direction the sheet is carried, each one of said sheet suction rollers comprising:
a metal hollow shaft having a hollow connected to said air exhausting means and having first air suction holes arranged in a line parallel to an axis of said hollow shaft and directed upward;
and
a metal hollow cylinder, enclosing said metal hollow shaft having a plurality of ring shaped ridges each having a plurality of second air suction holes directed outward, one of said second air suction holes coinciding with one of said first air suction holes as said metal hollow cylinder rotates around said hollow shaft, an aperture of said second air suction holes being mechanically slidingly connected to apertures of said first air suction holes as said hollow cylinder rotates around said hollow shaft and outer apertures of said second air suction holes touching the sheet being carried;
and
a metal sheet guide board covering said sheet suction roller having third air suction holes, upper peripheries of said ring shaped ridges extending through said third air suction holes provided in said sheet guide board, exposing certain ones of said second air suction holes.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/607,629Filed 31 Oct 1990 · continuation
Priority: JP 62-26623423 Oct 1987
Granted: 9 Jul 1991
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G03G 15/6532
Apparatus which relate to the handling of copy material: removing a copy sheet form a xerographic drum, band or plate
B65H 5/226
By suction devices: by suction rollers
G03G 15/657
Handling of sheet copy material taking place in a specific part of the copy material feeding path: feeding path after the transfer point and up to…
G03G 2215/00413
The feeding path segment where particular handling of the copy medium occurs, segments being adjacent and non-overlapping. Each segment is…:…