JP2956715B2 - Automatic paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic paper feeder provided in an image forming apparatus such as a copying machine or a laser beam printer, and more particularly to a structure of a sheet stacking table of the automatic paper feeder.

[0002]

2. Description of the Related Art Conventionally, in a deck-type sheet stacking table attached to an image forming apparatus, if the number of remaining sheets stacked on the table becomes small, sheets are not fed one by one, and all the remaining sheets are not fed. May be fed all at once. For this reason, a high-friction member is attached to the upper surface of the sheet stacking table so that sheets can be fed one by one up to the last sheet.

[0003]

However, in the above-mentioned conventional example, as shown in FIG. 3, when an operator supplies sheets P to the sheet stacking table a, the sheet P is provided at the downstream end of the sheet stacking table a. The lowermost sheet P1 of the sheet P may not be smoothly inserted into the high friction member b due to the frictional force of the high friction member b, and may be bent. In this case, the bent sheet P1 is transferred to the subsequent image forming apparatus. There is a problem that a paper jam may occur when the sheet is conveyed.

Accordingly, the present invention provides a high friction member provided on a sheet stacking table when replenishing a sheet.
Evacuate from the sheet loading table downward,
It is an object of the present invention to provide an automatic sheet feeder for preventing the lowest sheet to be supplied from being bent.

[0005]

According to the present invention, there is provided a feeding means for feeding sheets one by one, a sheet stacking table on which the sheets can be stacked and which can be moved up and down, and a part provided on the sheet stacking table. A high friction member, and a link member rotatably attached to the back surface of the sheet stacking table and holding the high friction member at one end, and the high friction member includes the sheet stacking table. Urging means for urging the link member so as to match the sheet mounting surface of the sheet stacking table; and the other end of the link member, which is disposed below the sheet stacking table and moves downward when the sheet stacking table moves during sheet replenishment. Abuts, and further, the sheet stacking table is moved downward to rotate the link member against the urging force of the urging means, thereby causing the high friction member to move. Characterized in that and a contact surface for retracting below the over preparative loading table.

[0006]

According to the above arrangement, when the sheet stacking table moves downward during sheet replenishment, the other end of the link member holding the high friction member at one end is brought into contact with the contact surface arranged below the sheet stacking table. Abut. When the sheet stacking table further moves downward, the link member is pressed against the contact surface and rotates against the urging force of the urging means, whereby the high friction member retreats to the lower side of the sheet stacking table. I do.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional side view of an automatic sheet feeder showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an automatic sheet feeder (hereinafter, referred to as an apparatus); The sheet stacking table 3 is moved up and down along the side plate 2 by an elevation drive means (not shown).

A downwardly facing bracket 3a is attached to the sheet stacking table 3, and the bracket 3a
A pin 6 is pivotally supported by a pin 5 and a high friction member 7 is attached to the end of the link 6 to look into a cutout 3b provided on the left side of the table 3 and a bracket 3a. A winding spring 9 for urging the link 6 in a clockwise direction is mounted between the link 6 and the link 6. Of the table 3
Is mounted below the vicinity of the notch 3b.

As shown in FIG. 2, a bottom plate 11 is provided below the table 3. When the base 3 of the link 6 is pressed against the bottom plate 11 when the table 3 is lowered, the link 3 6 rotates counterclockwise so that the high friction member 7 is retracted downward from the table 3.

As shown in FIG. 1, when the table 3 is set at a sheet feeding position by a sensor (not shown), the pickup roller 12 is brought into contact with the uppermost sheet P at a predetermined sheet feeding pressure. It has become.

The side plate 2 extends obliquely leftward to form a lower guide plate 13a.
An upper guide plate 13b is provided to face the upper side of the upper and lower guide plates 13a and 13b, and a sheet feed roller 15 and a retard roller 16 are provided at substantially base ends of the upper and lower guide plates 13a and 13b.
It is urged so as to be pressed at an intermediate position of b, and is disposed.

Next, the operation of this embodiment will be described.

When the operator replenishes the sheet P, the sheet stacking table 3 is lowered to a position shown in FIG. 2, and when the link 6 abuts against the bottom plate 11 which is the contact surface , the winding spring 9 Rotates counterclockwise against the urging force of
The high friction member 7 is lowered.

In this state, when the sheet P is replenished, the lowermost sheet P1 of the sheet P becomes the high friction member 7
The sheet P is smoothly slid on the table without touching the sheet P, and the supply of the sheet P is completed.

Next, the table 3 is raised, and a sheet feeding pressure is applied to the pickup roller 12 by a sensor (not shown).

Next, when the operator presses an image formation start switch (not shown), the uppermost sheet P of the sheets P is fed by the pickup roller 12. When two or more sheets P are to be fed by the feed roller 15 at one time, they are separated and fed back by the retard roller 16 and fed one by one toward the subsequent image forming apparatus.

[0018]

As described above, according to the present invention, when a sheet is to be replenished, the high friction member retracts below the sheet stacking table. The sheet can smoothly slide on the sheet stacking table to prevent the lowermost sheet from being broken, thereby facilitating sheet replenishment.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of an automatic sheet feeding apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional side view showing a state of sheet supply.

FIG. 3 is a vertical sectional side view showing a sheet supply state of a conventional automatic sheet feeding apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Automatic paper feeder 3 Sheet loading table 6 Link 7 High friction member 9 Winding spring 12, 15, 16 Feeding means (pickup roller paper feed roller, retard roller) P sheet P1 Lowest sheet

Claims (1)

(57) [Claims] A feeding means for feeding sheets one by one;
An automatic sheet feeder having a sheet stacking table on which the sheets are stacked and capable of moving up and down, and a high friction member provided on a part of the sheet stacking table, wherein the sheet stacking table is rotatably attached to a back surface of the sheet stacking table. A link member that holds the high friction member at one end; a biasing unit that biases the link member so that the high friction member is aligned with a sheet placement surface of the sheet loading table; disposed below, when the sheet supply <br/>, the other end of the link member with the downward movement of the sheet stacking table is brought into contact, further wherein the sheet stacking table
The link member is rotated downward against the urging force of the urging means by moving the link downward , and the high friction member is moved forward.
An abutting surface for retreating to a lower side of the sheet stacking table .