JPH033830A - sheet feeding device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sheet feeding device that separates and feeds a plurality of stacked sheets one by one.

<Prior art> In recording devices such as printers and copying machines, or document reading devices, multiple sheets (recording paper, manuscripts, etc.) are stacked.
A feeding device (often called a cut sheet feeder) for separating and feeding sheets one by one.

There are various types of sheet separation mechanisms for the feeding device, and a typical one uses separation claws. As shown in FIG.
2 and press the loading plate 50 with the pressing spring 53 to press the two-layer sheet 1-51 against the feeding roller 54,
When the feeding force is applied to the uppermost sheet 1-5 by the feeding roller 54, this sheet 51 is separated by the separating claw 52 and the feeding roller 5.
A loop is formed between the four sheets, and the sheet is then separated and fed one by one by overcoming the separating claw 52 with the strength of the grip.

<Problems to be Solved by the Invention> However, in the feeding mechanism, since the separating claws 52 and the feeding rollers 54 are located at both ends in the sheet width direction, as shown in FIG. When feeding the sheet 51, the separating claw 52 and the feeding roller 54 are separated widely from side to side, and loops are formed in the sheet 51 at both ends of the seal, but the loops are not formed neatly in the center and are bent in the opposite direction. The sheet may curl back and not be able to smoothly get over the separation claw 52, and furthermore, wrinkles may occur when the leading edge of the sheet hits the conveyance roller 55 to form a loop.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device that solves the above-mentioned conventional problems and can smoothly feed even wide sheets.

<Means for Solving the Problems> A typical means of the present invention for solving the above-mentioned problems includes separating claws for pressing both front end portions of the uppermost layer of a plurality of laminated sheets; an arcuate feeding roller having an arcuate portion that contacts the sheet and an arcuate portion that can separate from the sheet in order to apply a feeding force to the sheet;
The present invention is characterized in that an arcuate auxiliary roller is provided coaxially with the feeding roller and has an arcuate portion that contacts the sheet and an arcuate portion that can be separated from the sheet.

<Operation> In the above means, the sheets are separated and fed one by one by the rotation of the feeding roller and the action of the separating claw. At this time, even if the sheet is wide, it is held down by the auxiliary roller, so that a sheet loop can be formed neatly even in the center in one width direction, and smooth separation and feeding can be achieved.

<Example> Next, an example of a recording apparatus to which the above-mentioned means is applied will be described.

FIGS. 1 and 2 are explanatory diagrams of the configuration of a sheet feeding device according to this embodiment.

First, to explain the general structure of the whole, a mounting plate 3 that is urged upward by a pressing spring 2 is housed inside the frame 1, and a large number of recording sheets 4 are stacked on this mounting plate 3. When the feeding roller 5 is rotated in the direction of the arrow in FIG. There is. Further, during the feeding, the recording sheet 4 is configured to be fed while being pressed by an auxiliary roller 9 attached coaxially with the shaft 8 to which the feeding roller 5 is attached.

Next, to specifically explain the structure of each part, the frame body 1 is divided into a left half part 1a and a right half part 1b, and by sliding them along the axis 8, the frame body 1 is adjusted in the full width direction of the sea I. It is now possible to do so. The placing plate 3 is also housed separately in the left and right frames 1a and 1b, and each placing plate 3 is urged upward by a pressing spring 2, whereby the top of the recording sheets 4 stacked on the placing plate 3 is pushed upward. The upper layer is the feeding roller 5
It is configured so that it comes into pressure contact with the

As shown in FIG. 1, Zide guides 10 are provided on the outer walls of the left and right frames 1a, 1b to guide both ends of the recording sheet 4. As shown in FIG.

Next, as shown in FIG. 1, the feeding roller 5 is integrated with the shaft 8 by fitting the projection 5a of the roller 5 into the groove 8a formed in the shaft 8 to which the driving force from the motor (not shown) is transmitted. Although the recording sheet 4 rotates, it is attached so as to be slidable in the thrust direction, and is configured so that it can be set at an appropriate position depending on the width of the recording sheet 4 to be set.

The outer circumferential portion of the feeding roller 5 is made of a high-friction member such as rubber, and as shown in FIG. It is formed into an arcuate shape having a short arc section 5c separated from the recording sheet 1-4, and when this feeding roller 5 rotates, the arc section 5b comes into pressure contact with the recording sheet 4, and the arc section 5c presses against the recording sheet 4. 4
It is configured to be separated from the

The separating claws 6 are formed integrally with the frame 1, and each has a claw portion 6a that presses a front end corner of the recording sheet 4, and an abutment portion 6b that abuts the leading edge of the sheet.

Next, regarding the auxiliary roller 9, similar to the feed roller 5, the protrusion 9a of the roller 9 fits into the groove 8a formed on the shaft 8, and the roller 9 rotates integrally with the shaft 8. 2
The feed roller 5 is attached so as to be slidable in the thrust direction between the feed rollers 5 .

Furthermore, the shape of the auxiliary roller 9 is similar to that of the feeding roller 5, with an arc portion 9b that contacts the recording sheet 1-4, and an arc portion 9c that is shorter in diameter than the arc portion 9b and is spaced apart from the recording sheet 4. The auxiliary roller 9 is formed into a bow-like shape, and is attached so that when the arc portion 5b of the feeding roller 5 contacts the sheet 4, the arc portion 9b of the auxiliary roller 9 also contacts the sheet 4.

Next, the operation when feeding the recording sheet 4 by the apparatus configured as described above will be explained.

First, as shown in FIG. 3 (al), the recording sheets 4 are stacked on the mounting plate 3, the two feeding rollers 5 are set near both ends of the sheet 4 in the width direction, and the auxiliary rollers 9 is set approximately near the center.When the shaft 8 is rotated in the direction of the arrow in this state, the arc portion 5b of the feeding roller 5 rotates in pressure contact with the sheet 4, and a propulsive force is applied to the sheets 1 to 4 of the uppermost layer. At this time, since the leading edge of the sheet 4 abuts against the abutting portion 6C of the separation claw 6, a loop is formed between the separation claw 6 and the feeding roller 5 as shown in FIG. Even if the recording sheet 4 is wide, as shown in FIG.
will guide you, and an even loop will be formed throughout. Therefore, even when separating and feeding a wide recording sheet 4, the sheet 4 can be separated and abutted smoothly.
The occurrence of wrinkles and skewing are effectively prevented.

Next, when a loop is formed to a certain extent, the leading edge of the sheet comes off from the separating claw 6 due to the stiffness of the sheet 4, as shown in FIG. 4 is separated and fed. The recording sheet 4 separated in this way is further fed by the rotation of the feeding roller 5, and as shown in FIG. By forming a loop, skew, etc., can be corrected.

The recording sheet 1-4 nipped by the conveyance roller 7 and the pinch roller 7a is conveyed to a predetermined recording section etc. by the rotation of the conveyance roller rough, and at this time, the feed roller 5 and the auxiliary roller 9 are moved to the initial position. Return to arc parts 5c and 9c
is facing downward and is separated from the recording sheet 4. Therefore,
When this is used in a recording device, there will be no problem such as fluctuations in the sheet conveyance load and disturbances in the feed pitch when the rear end of the sheet 4 comes off the feed roller 5 during recording. Further, even when the sheet is reversely fed by the conveyance roller rough, the trailing edge of the sheet does not hit the feed roller 5 and the auxiliary roller 9 and jam.

In the above-mentioned embodiment, one auxiliary roller 9 was provided, but two auxiliary rollers may be provided at the widthwise center of the sheet 1, or a plurality of auxiliary rollers may be used to feed They may be arranged evenly between the rollers 5.

Further, when the width of the sear 1-4 is limited to a relatively narrow one, an auxiliary roller having a length approximately equal to the distance between the two feeding rollers 5 may be provided.

Furthermore, in the above-mentioned embodiment, an example was shown in which the separation claw 6 was formed integrally with the frame 1, but only the claw portion 6a was formed integrally with the frame 1, and the abutment made of a separate member from the claw portion 6a was formed integrally with the frame 1. The portion 6b may be attached to the frame 1 with screws or the like.

<Effects of the Invention> As mentioned above, the Japanese invention provides an auxiliary roller in addition to the feeding roller, so even when feeding wide sheets, sheet loops can be neatly formed in the width direction, allowing smooth separation and feeding. It is possible to do this.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of the configuration of a sheet feeding device according to an embodiment of the present invention, FIG. 3 (al to (d+) is an explanatory diagram of the separated feeding state, 1 is an explanatory diagram of the prior art. 1 is a frame body, 1a is a left half, 1b is a right half, 2 is a pressure spring, 3 is a mounting plate, 4 is a recording sheet, 5 is a feeding roller, 5a
is a protrusion, 5b is an arc, 5C is an arc, 6 is a separation claw, 6a
is a claw part, 6b is an abutment part, 7 is a conveyance roller, 8 is a shaft, 8a
9 is a groove, 9 is an auxiliary roller, 9a is a protrusion, and 10 is a side guide.

Claims (2)

[Claims] (1) Separation claws that press the front ends on both sides of the topmost sheet of a plurality of stacked sheets, an arc portion that contacts the topmost sheet to apply feeding force to the sheet, and a sheet. an arcuate feeding roller having a chord part that can be separated from the sheet; and an arcuate auxiliary roller that is provided coaxially with the feeding roller and has an arc part that contacts the sheet and a chord part that can be separated from the sheet. A sheet feeding device having the following. (2) Claim (1) wherein there are two said feeding rollers, and said auxiliary roller is arranged approximately in the middle of said two feeding rollers.
) sheet feeding device.