JPH0730598Y2 - Single sheet feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a sheet feeding apparatus such as a copying machine, a facsimile machine, a printing machine or the like, which separates and stacks sheet-by-layer sheets one by one. .

[Prior Art] A single-sheet feeding device for separating and sequentially feeding stacked single-wafer sheets in the prior art is, for example, a third sheet feeding device.
The format is as shown in FIGS. 4, 4 and 5 and 6.

In either type, the laminated sheet P is mounted on the feeding table 22 which is pushed up by the compression spring 21 with its front edge abutting on the left restraining plate 23 in the drawing. The upper surface of the uppermost sheet P1 of the laminated sheet P is in contact with the lower peripheral surface of the first feeding roller 24, and the first feeding roller 24 is rotated clockwise in the drawing to cause the sheet P1 to rotate. Is a restraint plate to the left in the downstream drawing
Delivered over the top of 23.

At that time, by friction with the uppermost sheet P1, the second layer sheet P2
Separation measures have been taken to prevent them from being fed together.

In the friction plate type separating means shown in FIG. 3, the upper end portion of the inhibition plate 23 is bent in the downstream direction, and the surface forming the upper surface thereof is configured as the friction plate 25, and faces the friction plate 25. And the second feeding roller 26 is provided, and the second feeding roller 26 is the first
It is rotated in the same direction as the feeding roller 24.

Even if the sheet P2 of the second layer is about to be fed together with the sheet P1 of the uppermost layer, the front end of the sheet P2 rides on the friction plate 25 and the forward movement is suppressed, and only the sheet P1 is moved by the second feeding roller 26. Will be delivered.

The separating means of the reverse rotation roller type shown in FIG. 4 is replaced with the friction plate 25 in the friction plate type of FIG.
The return roller 27 that rotates in the same direction as the second feed roller 26
Is provided opposite to.

Even if the sheet P2 of the second layer is about to be fed together with the sheet P1 of the uppermost layer, the front end of the sheet P2 of the second layer comes into contact with the upper peripheral surface of the return roller 27 and the forward movement is suppressed, so that the sheet P1 Only the second feeding roller 26 is fed.

The separating claw type separating means shown in FIG. 5 and FIG.
Separation claws 28 are formed toward the upstream side at both ends of the upper edge of the restraining plate 23 (positions that contact both side edges of the sheet).

The uppermost sheet P1 tries to move forward by the clockwise rotation of the first feeding roller 24, but since both ends of the leading edge of the sheet P1 are prevented from moving forward by the separating pawls 28, the first feeding roller 24 and the separating pawls are separated. The sheet P1 is rolled up in an arch shape with respect to the sheet 28 and peels off from the second layer sheet P2. Finally, the elasticity of the sheet P1 itself causes the front edge to spring away from the separating claw, and only the sheet P1 is released. It will be fed over the upper end of the restraint plate 23.

[Problems to be Solved by the Invention] Each of the above-described conventional sheet feeding apparatuses has a drawback.

First, the friction plate method separates the vertically stacked sheets due to the difference between the friction coefficient of the sheet with respect to the feeding roller and the friction coefficient of the sheet with respect to the friction plate, so that it is difficult to deal with uneven surface conditions of each sheet. Sheet feeding is likely to occur.

In the reverse rotation roller method, the lower side surface of the sheet fed by the second feeding roller is rubbed by the upper peripheral surface of the return roller, and is soiled. Particularly, in the case of a writing sheet, contamination is likely to occur.

In the case of the separation claw method, there is a limit to the size of the separation claw,
Sheets tend to fold and feed two sheets, and it is difficult to handle wide sheets.

[Means for Solving the Problems] A single sheet feeding device of the present invention includes a feeding table that is elastically supported and on which a laminated sheet is mounted; and a lowering device that lowers a downstream side portion of the feeding table. A restraining plate that is erected adjacent to the downstream side edge of the feeding table and has a rib-like sheet pressing portion that faces the upstream side at the upper edge; and a feeding pressing roller that is upstream of the sheet pressing portion. A feed roller which is provided as a pair and is driven to rotate so that the peripheral surface faces the upstream side at the position facing the upper surface of the laminated sheet, and the peripheral surface faces the downstream side at the position facing the feed pressing roller; Is provided at a space upstream of the
The lower peripheral surface facing the laminated sheet is composed of a guide roller rotatable in one direction so as to face only the feeding direction.

[Operation] The laminated sheet is mounted on the feeding table with its front edge abutting against the restraining plate, and the upper surface of the uppermost sheet elastically elastically forms the lower surface of the sheet pressing portion and the feeding roller and the guide roller. It is in a state of being pressed against each lower peripheral surface.

When the feeding operation is started, the feeding roller is first driven to rotate. Then, the front end of the uppermost sheet is retreated to the upstream side by the feeding roller, but the rear end of the sheet is
The guide roller prevents the retreat. Therefore, the sheet is bent upward between the feeding roller and the guide roller in an arch shape, and the front edge of the sheet comes out of the sheet pressing portion.

The front edge of the sheet that has slipped out of the sheet pressing portion further passes through the lower peripheral surface of the feeding roller, and then the elastic return of the arch-shaped deflection of the sheet itself causes the sheet to come into contact with the peripheral surface of the feeding roller while feeding the pressing roller. Head towards.

On the other hand, when the front edge of the uppermost sheet passes the lower peripheral surface of the feeding roller, the laminated sheet is constantly pressed upward by the feeding table, so that the sheet of the next layer is the lower peripheral surface of the feeding roller. , The front end of the uppermost sheet retreats, and begins to bend upward between the feeding roller and the guide roller in an arch shape.

However, at this time, the lower end of the feeding table is lowered by the lowering device, and the upper surface of the sheet of the next layer is separated from the lower peripheral surface of the feeding roller, so that the sheet of the next layer is elastically returned by itself. It extends and returns to the position where the front edge contacts the restraining plate again.

During this time, the front edge of the uppermost sheet is caught in the feed pressing roller while being in contact with the peripheral surface of the feeding roller.
The sheet is fed to the sheet feeding roller while being pressed by the sheet feeding pressing roller. At this time, since the guide roller is rotatable in the sheet feeding direction, the guide roller rotates around the forward movement of the sheet and does not interfere with the forward movement of the rear end portion of the uppermost sheet, that is, the sheet feeding. Eventually, when the trailing edge of the uppermost sheet passes the feeding roller, the rotational drive of the feeding roller is stopped, the lowering device releases the feeding table, and the feeding table elastically rises, Return to the initial state.

[Embodiment] An embodiment of the present invention is shown in FIGS. 1 (a), (b), (c) and (d).
(E) and (f) will be described.

In the sheet feeding device, the feeding table 1 is supported by a compression spring 2 on the front end side (the left end side in FIG. 1), and the front end side is pushed down from above to descend, so that the feeding table 1 itself tilts. It is supposed to be done. As means for lowering the front end side of the feeding table 1, the feeding table 1 has a protruding portion 3 formed laterally (perpendicular to the paper surface) on the front end side, and is in contact with the upper surface of the protruding portion 3 and is eccentric, for example. A cam 4 such as a cam is provided.

A restraint plate 5 is erected adjacent to the front end (left end in FIG. 1) of the feeding table 1, and the upper end of the restraining plate 5 is bent in the same direction as the feeding table 1 on the upstream side, and the sheet pressing portion 6 is provided. And the lower surface of the sheet pressing portion 6 is subjected to Teflon processing for anti-friction effect.

Adjacent to the end of the sheet pressing portion 6 and in parallel with the sheet pressing portion 6 (perpendicular to the paper surface in FIG. 1), the feeding roller 7 is rotationally driven counterclockwise in FIG. 1 by a driving device (not shown). Is provided. A guide roller 8 is provided in parallel with the feeding roller 7 with a space therebetween so as to be rotatable only clockwise in FIG. 1 via a one-way clutch (not shown).

The lower peripheral surfaces of the feeding roller 7 and the guide roller 8 have substantially the same height as the lower surface of the sheet pressing portion 6, and the guide roller 8
The position of is a position where the front end edge is in contact with the suppression plate 5 and is in contact with the upper surface of the laminated sheet P on the rear end side.

A feeding and pressing roller 9 is rotatably provided in parallel with the feeding roller 7 and obliquely above the rear side of the feeding roller 7 (upwardly to the right in FIG. 1). The sheet is pressed against the peripheral surface of the feeding roller 7 by sandwiching the sheet.
The inlet is adjacent to the downstream side of the position where the feeding roller 7 and the feeding pressing roller 9 face each other, and is obliquely above the downstream side (upward to the left oblique side in FIG. 1).
A feeding guide 10 is provided toward the.

Thus, a storage space for the laminated sheet P to be fed is formed between the upper surface of the feeding table 1, the lower surface of the sheet pressing portion 6, the lower peripheral surface of the feeding roller 7 and the lower peripheral surface of the guide roller 8. To be done.

The operation and action of the sheet feeding device will be described.

In the storage space, the laminated sheet P is mounted on the feeding table 1 so that the front end of the laminated sheet P abuts the restraining plate 5. At that time, the cam 4 is in a state where the feeding table 1 is opened, the lowermost sheet Pn is in contact with the feeding table 1, and the upper surface of the uppermost sheet P1 is pressed by the compression spring 2 with some spring force. The lower surface of 6 and the feeding roller 7 are pressed against the lower peripheral surfaces of the guide rollers 8 [FIG. 1 (a)].

When the feeding operation is started, first, the feeding roller 7 is rotationally driven counterclockwise by the driving device. Then, the front end of the uppermost sheet P1 is retracted by the feeding roller 7 (to the right in FIG. 1), but the rear end of the sheet P1 is a guide whose counterclockwise rotation is suppressed by a one-way clutch. The roller 8 prevents the retreat.

Therefore, the sheet P1 is bent upward between the feeding roller 7 and the guide roller 8 in an arch shape, and the front edge of the sheet P1 comes out of the sheet pressing portion 6. At this time, since the lower surface of the sheet pressing portion 6 is subjected to Teflon processing, it smoothly comes out [Fig. 1 (b)].

The front edge of the sheet P1 that has come out of the sheet pressing portion 6 further passes through the lower peripheral surface of the feeding roller 7, and then contacts the peripheral surface of the feeding roller 7 due to the elastic return of the arched bending of the sheet P1 itself. While facing the feeding presser roller 9.

On the other hand, when the front edge of the uppermost sheet P1 passes the lower peripheral surface of the feeding roller 7, the laminated sheet P is constantly pushed upward by the spring force of the compression spring 2 via the feeding table 1. So
The second layer sheet P2 contacts the lower peripheral surface of the feeding roller 7,
Since the front edge of the sheet P1 retreats like the sheet P1, the sheet begins to bend upward between the feeding roller 7 and the guide roller 8 in an arch shape [Fig. 1 (c)].

However, at that time, the rotation of the cam 4 is started, the front end of the feeding table 1 is pushed down against the spring force of the compression spring 2 by the operation of the cam 4, and the upper surface of the sheet P2 is fed by the feeding roller. Since the sheet P2 is separated from the lower peripheral surface of the sheet 7, the sheet P2 expands due to the elastic return of its own arch-shaped flexure, and returns to the position where the front edge of the sheet P2 abuts against the restraining plate 5.

During this time, the leading edge of the sheet P1 is caught between the feeding roller 7 and the feeding pressing roller 9 while being in contact with the peripheral surface of the feeding roller 7 [FIG. 1 (d)].

Then, the sheet P1 is fed into the feeding guide 10 while being pressed by the feeding pressing roller 9 by the feeding roller 7. At this time, the feeding and pressing roller 9 rotates clockwise, and the clockwise rotatable guide roller 8 also moves forward of the sheet P1 until the trailing edge of the sheet P1 comes out of the peripheral surface of the guide roller 8. The feeding roller 9 rotates around and does not interfere with the forward movement of the sheet P1, that is, the rear end of the sheet P1.
The sheet P1 is smoothly delivered to the feeding guide 10 by [Fig. 1 (e)].

Eventually, the sheet P1 fed in the feeding guide 10 is nipped by a preceding feeding roller (not shown), and thereby fed to a predetermined position, and the trailing edge of the sheet P1 is fed to the feeding roller 7 and the feeding roller 7. When the feeding roller 7 is separated from the pressing roller 9, the driving of the feeding roller 7 is stopped and the cam 4 is rotated to open the feeding table 1, so that the feeding table 1 is raised by the spring force of the compression spring 2,
The laminated sheet P is pushed up again so as to press the uppermost sheet P2 against the lower surface of the sheet pressing portion 6 and the lower peripheral surfaces of the feeding roller 7 and the guide roller 8 to restore the initial state [first (F)].

[Effect of the Invention] In the sheet feeding apparatus of the present invention, the feeding roller for feeding the sheet, the feeding pressing roller, and the unidirectionally rotatable guide roller are in the same positions, and the guide rollers are laminated. When the front edge of the uppermost sheet of the laminated sheet passes through the lower peripheral surface of the feeding roller by the feeding roller while being pressed against the sheet, the eccentric cam pushes down the downstream side of the feeding table. The lower peripheral surface of the feeding roller is separated from the upper surface of the sheet of the next layer.

Therefore, in this configuration, when the uppermost sheet is fed and the next laminated sheet is fed, the next sheet is again the same as the previous sheet due to the rise of the elastically supported feeding table. Since it is located at the position, there is no change in the feeding path of the sheet to be fed, and since the feeding table is lowered by using the eccentric cam, the overall structure is always simple. Sheets can be fed under certain conditions.

Further, since the sheet is bent and sent out, the separability is good and the friction between the sheet and the roller is small, so that the sheet is not damaged. Further, since it is bent over the entire width of the sheet to be separated, it can be applied to a wide sheet, and it can be applied to various sheets because there is no restriction on the sheet of different thickness and the quality of the sheet surface.

[Brief description of drawings]

1 (a) to 1 (f) are schematic front views showing the construction and operation of the sheet feeding device in the embodiment of the present invention, and FIG. 2 is a partial sectional view taken along the line II-II of FIG. 3 to 5 are schematic front partial views of the sheet feeding device in the prior art, and FIG. 6 is a plan partial view of the sheet feeding device of FIG. 1 ... Feeding table, 2 ... Compression spring, 3 ... Projection part, 4 ...
Cam, 5 ... Suppression plate, 6 ... Sheet pressing part, 7 ... Feed roller, 8 ... Guide roller, 9 ... Feed pressing roller,
10 …… Feeding guide, P …… Laminate sheet, P1,2 …… Sheet.

Claims (1)

[Scope of utility model registration request] 1. A feed table on which a laminated sheet is mounted, which is elastically supported; and a sheet which is erected upright adjacent to a downstream end edge of the feed table and has a rib-like shape facing the upstream side at the upper end edge. A restraining plate formed with a pressing portion; a feeding pressing roller provided on the upstream side of the sheet pressing portion in a pair with the feeding pressing roller so that the peripheral surface faces the upstream side at a position facing the upper surface of the laminated sheet. And a feeding roller that is driven to rotate toward the downstream side at a position facing the feeding roller; and is mounted on the elastically supported feeding table that is provided on the upstream side of the feeding roller in parallel with and spaced from the feeding roller. A guide roller that is unidirectionally rotatable so that the lower peripheral surface that is in a pressed state against the laminated sheet and faces the laminated sheet only in the feeding direction; and the sheet front end of the uppermost layer of the laminated sheet by the feeding roller. When the edge passes through the lower peripheral surface of the feeding roller, downstream of the feeding table A sheet feeding apparatus including an eccentric cam that lowers the downstream side portion of the feeding table, which acts to separate the lower peripheral surface of the feeding roller from the upper surface of the next layer sheet; .