CN-117279848-B - Paper feeder

CN117279848BCN 117279848 BCN117279848 BCN 117279848BCN-117279848-B

Abstract

The invention provides a paper feeding device capable of inhibiting poor paper conveyance such as jam for a long time. The paper feeding device (1) has a feed roller (10) and a retard roller (20). A plurality of protruding strips (13) which extend with the axial direction (S1) of the feed roller (10) and the axial direction (S1) in the circumferential direction (C1) as main components are arranged on the outer peripheral surface (11) of the feed roller (10) along the circumferential direction (C1). A plurality of circumferential protruding strips (23) which are extended with the circumferential direction (C2) of the axial direction (S2) and the circumferential direction (C2) of the delay roller (20) as main components are arranged on the outer circumferential surface (21) of the delay roller (20) along the axial direction (S2), and a plurality of axial protruding strips (24) which are extended with the axial direction (S2) of the axial direction (S2) and the circumferential direction (C2) as main components are arranged along the circumferential direction (C2). In an expanded view in which the outer peripheral surface of the retard roller (20) is expanded to a flat surface, the circumferential ridge (23) extends linearly, and the axial ridge (24) extends linearly.

Inventors

Onizuka Chino

Assignees

山内株式会社

Dates

Publication Date: 20260505
Application Date: 20220204
Priority Date: 20210416

Claims (3)

1.A paper feeding device, wherein, The paper feeding device comprises: a feed roller to which a driving force for conveying the sheet is applied, and A retard roller configured to be rotatable in conjunction with the feed roller by applying the driving force from the feed roller, the retard roller being configured to impart a predetermined rotational resistance in a direction opposite to a rotational direction during the cooperative rotation, A plurality of ribs extending mainly in the axial direction of the feed roller and the axial direction in the circumferential direction of the feed roller are provided on the outer circumferential surface of the feed roller, grooves are formed between the two ribs, the ribs and the grooves are alternately arranged in the circumferential direction of the feed roller, In an expanded view of expanding the outer peripheral surface of the feed roller into a flat surface, the convex strip and the groove portion linearly extend, so that the feed roller is formed into a knurled shape, A plurality of circumferential ridges as ridges extending mainly in the circumferential direction of the retard roller are provided on the outer circumferential surface of the retard roller along the axial direction of the retard roller, and a plurality of axial ridges as ridges extending mainly in the axial direction of the retard roller and the axial direction of the retard roller are provided along the circumferential direction, In an expanded view of expanding the outer peripheral surface of the retard roller into a flat surface, the circumferential ridge extends linearly and the axial ridge extends linearly, so that the circumferential ridge and the axial ridge are arranged in a lattice shape in the retard roller.
2. The paper feeding apparatus according to claim 1, wherein, The ribs of the feed roller extend in the axial direction of the feed roller, The circumferential ridge of the retard roller extends along the circumferential direction of the retard roller, and the axial ridge of the retard roller extends along the axial direction of the retard roller.
3. The sheet feeding device according to claim 1 or 2, wherein, The plurality of circumferential ridges are arranged at equal pitches in the axial direction of the retard roller.

Description

Paper feeder Technical Field The present invention relates to a paper feeder suitable for use in image forming apparatuses such as copiers, printers, multifunction peripherals, facsimile machines, and the like. Background Image forming apparatuses such as copiers, printers, multifunction peripherals, and facsimile machines have various rollers (for example, refer to patent document 1). As a device including a roller, a paper feeding device for feeding paper sheet by sheet as described in patent document 1 is known. The paper feeding device includes, for example, a pickup roller, a feed roller, and a retard roller. For example, although called different according to a person skilled in the art, in a paper feeding device called an FRR (reverse feed roller) system, a pickup roller conveys a paper from a tray to a separating portion. The separating section has a feed roller, a retard roller, and a torque limiter. The retard roller is in pressurized contact with the feed roller. The separating portion prevents overlapped feeding of sheets. More specifically, when a paper feed instruction is issued, the pickup roller and the feed roller start to rotate. At this time, the retard roller in contact with the feed roller in a pressurized state also rotates together with the feed roller. The sheet fed out from the tray by the pickup roller enters between the feed roller and the retard roller, and advances while being pressurized by the feed roller and the retard roller. At this time, the retard roller is applied with a rotational force by the torque limiter in a direction to return the sheet. The retard roller is normally rotated in a direction of feeding out the sheet by receiving a rotational force from the feed roller through one sheet. On the other hand, there are cases where two sheets are erroneously fed out by the pickup roller. In this case, when two sheets enter between the feed roller and the retard roller, since the retard roller is applied with a predetermined torque in a direction of pushing the sheets back toward the tray side, it is rotated by the rotation of the torque, and the sheet in contact with the retard roller is returned toward the tray side. As a result, only the sheet in contact with the feed roller advances. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 62-65859 Disclosure of Invention Problems to be solved by the invention In such a paper feeding apparatus, when the paper feeding operation is repeated, paper dust or the like adheres as fine powder to the surface of the feed roller and the surface of the retard roller. If such fine powder exists on the surfaces of the feed roller and the retard roller, the friction coefficient of the surfaces of these rollers decreases, and it is difficult to stably convey the paper. As a result, a conveyance failure of the paper such as a jam may occur. The paper feed roller described in patent document 1 is formed with fine grooves extending in a substantially arch shape from one end to the other end in the axial direction of the roller at predetermined intervals in the circumferential direction. The fine groove is provided for receiving and discharging paper dust adhering to the surface of the paper. As described in patent document 1, a structure is known in which grooves are provided in rollers in order to suppress a decrease in friction force between the rollers and paper due to fine powder such as paper dust. In such a paper feeding apparatus, it is required to suppress paper conveyance failure and paper jam for a longer period of time and more reliably. In addition, in patent document 1, attention is paid only to a single roller, and no attention is paid to the relationship between rollers in a paper feeding device including a plurality of rollers such as a feed roller and a retard roller. In view of such a background, an object of the present invention is to provide a paper feeding device capable of suppressing a paper conveyance failure such as a jam for a long period of time. Solution for solving the problem The inventors of the present application have conducted intensive studies and as a result, have found that improvement of a feed roller and a retard roller in association with each other is effective in suppressing a defective conveyance or a jam of a sheet without focusing on individual rollers of the feed roller and the retard roller, and have arrived at the present application. The present invention is directed to the following paper feeding apparatus. (1) A paper feeding device, wherein, The paper feeding device comprises: a feed roller to which a driving force for conveying the sheet is applied, and A retard roller configured to be rotatable in conjunction with the feed roller by applying the driving force from the feed roller, the retard roller being configured to impart a predetermined rotational resistance in a direction opposite to a rotational direction during the cooperative rotation, A plurali