JPH03216421A - High capacity feed sheet cassette - Google Patents

Abstract

PURPOSE:To prevent reduction of a rising and press drive force for a sheet placing plate and the occurrence of the defective feed of sheets by forming a sheet collision reference surface, similar to the rotation locus of the tip of the sheet placing plate, in a high capacity feed sheet cassette. CONSTITUTION:A sheet placing plate 12 rotatable around the center of a rotation fulcrum axis part 12B is located in a feed sheet cassette casing 11 capable of containing quantities of sheets S. An inclining sheet collision reference surface 11D similar to the rotation locus of a tip 12A of the sheet placing plate 12 is formed in the cassette casing 11. This constitution prevents reduction of a rising and press drive force for the sheet placing plate 12 of a high capacity feed sheet cassette capable of containing quantities of the sheets S and the defective feed of sheets due to irregular arrangement of the sheets S on the sheet placing plate 12.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to paper feeding devices of various image recording devices such as copying machines such as porcelain photocopying machines, computer output printers, and light printing machines. The present invention relates to a paper feed cassette used as a paper feed cassette, and specifically relates to a large capacity paper feed cassette that can accommodate a large amount of recording paper and supply it to a recording section.

[Conventional technology]

In each of the above-mentioned image recording devices, various cut sheets such as plain paper, printing paper, photosensitive paper, pressure-sensitive paper, thermal paper, electrostatic recording paper, transfer paper, synthetic resin recording sheet, etc. are fed and transported by the main body of the recording device. When feeding the paper to the
Load this into the cassette receiver of the main body of the device and feed the paper.
A so-called cassette paper feeding system is used.

Such paper feed cassettes are usually small in size, and the amount of recording paper (or "sheets") they can accommodate is limited to about 100 to 250 sheets. has the disadvantage that it requires frequent replenishment.

Recently, in this type of high-speed recording apparatus, in response to the above-mentioned high operating rate, there has been a demand for a large-capacity sheet feeding capacity capable of accommodating 500 to 1000 sheets.

However, simply increasing the depth of the casing of a conventional paper feed cassette in order to increase the sheet storage capacity causes problems during paper feeding.

Such a paper feed cassette will be explained according to an example shown in FIG. A large number of sheets S are stacked and placed on the upper surface of a sheet placement plate 2 within a housing 1 of the paper feed cassette. At this time, the leading ends of the sheets S abut against the sheet abutment reference surface A on the inner surface of the casing l, and are housed in alignment. If you push this paper cassette into the paper feed section of the recording device and install it,
Rotation *i+3 is rotated by a drive means (not shown) to rotate the push-up lever 4 counterclockwise, and its tip member 5 presses the bottom side of the sheet mounting plate 2 and moves upward in the direction of the arrow. . As a result, the sheet placement plate 2 rotates clockwise about the fulcrum shaft part IB provided at the bottom of the casing l,
The tip portion 2A moves upward while drawing a locus of movement in the direction of the arrow. Then, the top layer of the sheets S stacked on the sheet stacking plate 2 comes into pressure contact with the peripheral surface of the feed roller 6 of the paper feeding device with a predetermined force, and the drive is stopped and the pressure contact is maintained.

Next, in response to the paper feed signal, the feed roller 6 rotates and the sheets S are sent out, and only the topmost sheet S is fed to the recording section by the separation action of the separation roller 7 and double feed prevention roller 8. Ru.

When the sheet S continues to be fed and the number of sheets on the sheet placement plate 2 decreases, the driving means is driven and the push-up lever 4 rotates upward to send out the sheet bundle to the roller 6 with a predetermined pressure. Press.

The bundle of sheets S stacked on the sheet placement plate 2 and aligned against the abutting reference surface IA of the housing l is lifted as the sheet placement plate 2 rotates. In a large-capacity paper feed cassette housing l with a deep depth capable of accommodating a large amount of sheets S, when the number of sheets on the sheet placement plate 2 decreases, the leading edge of the sheet S becomes as shown in FIG. The sheet rises in an arc trajectory as shown by the arrow, gradually moves away from the sheet abutting reference surface IA, and reaches the vicinity of the surface of the feed roller 6, but the sheet is not pressed or the pressure is incomplete, so that the sheet is not pushed by the feed roller 6. Delivery becomes impossible or unstable. Also, even if the sheet S
However, the sheet comes into contact with the upper surface of the separating roller 7 and the double-feed prevention roller 8, which is much higher than the nip position, and feeding is blocked, resulting in paper feeding failure.

FIG. 4 is a sectional view showing another conventional example of a large-capacity paper feed cassette. In order to solve the above problem, sheet mounting plate 1
2, move the pivot shaft part 12B to approximately the center of the depth of the casing 11, and use the arm part 12c to move the pivot shaft part 12B to the center of the depth of the casing 11.
The structure is designed to support the

As a result, the rotation trajectory of the tip 12A of the sheet placement plate l2 and the trajectory of the tip of the sheet S placed on the sheet placement plate l2 draw an arc as shown in FIG. . However, when the maximum number of sheets S is loaded on the sheet mounting plate l2 and the sheet mounting plate l2 is attempted to be lifted, the sheet S
The tip of the sheet is pushed up by the sheet mounting plate l2, and
While being pinched between the feed roller 6 in the fixed position, it is rotated upwardly in an arc indicated by the solid line arrow, but the total volume of 1 l
The abutting reference surface 11AJ is blocked and moved in eight directions by the width δφ.

This results in a loss of lifting force for the fourth push-up lever.
Is there a problem with paper feeding because the proper feeding force cannot be obtained? Ru.

[Problem that the invention attempts to solve]

■This invention is particularly useful when placing 500 to 10 sheets of paper on the paper tray as described in 6 above.
To improve the above-mentioned problems in a large-capacity paper feed cassette in which a large amount of 000 sheets is fed by raising a push-up lever using a driving force and pressing the sheet against the delivery U-5 with a predetermined pressure. It is an object of the present invention to provide a large-capacity paper feed cassette that reduces the upward pressing driving force of the stacking plate and eliminates paper feeding failures.

[Means to solve the problem]

The large-capacity paper feed cassette of the present invention that achieves the above object has the following features:
In a large-capacity paper feed cassette in which a rotatable sheet placement plate is provided in a paper feed capacity housing capable of accommodating a large amount of sheets, a sheet having a shape that approximates the rotation locus of the tip of the sheet wax placement plate. The present invention is characterized in that the abutment reference surface is formed within the paper feed cassette housing.

[Example]

This invention will be explained below with reference to an embodiment shown in the appendix.

Fig. 1 is a sectional view showing a large capacity paper feed cassette according to the present invention installed in the paper feed section of a recording device such as a copying machine, and Fig. 2 is an exploded view of the large capacity paper feed cassette. FIG.

Regarding the reference numerals used in these drawings, parts having the same functions as those in FIG. 4 are given the same numbers. Also, points different from the conventional example described above will be explained.

A paper feeding section of a recording device such as a copying machine is provided with the feed roller 6.
, a separating roller 7, and a double-feed prevention roller 8, an upper paper feeding section, a case loading section 10 provided below the paper feeding section in which the housing 11 of the paper feeding cassette is mounted and placed in a predetermined position, and a paper feeding section 10 in the paper feeding cassette. a push-up lever 4 that supports a tip member 5 for vertically swinging the sheet placement plate l2; a swinging section comprising a rotating shaft 3 that is integral with the push-up lever 4 and connected to a drive source; It is configured.

Grooves 11B are provided on both side walls of the housing 11 of the paper feed cassette.
．． IIB and holes 11C and IIc at its lower end are provided.

Through this groove portion 11B, a flat surface portion of a rotation fulcrum shaft portion 12B fixed to the arm portions 12C at both ends of the sheet placement plate l2 can pass. Further, the cylindrical surface portion of the rotation fulcrum shaft portion 12B is fitted into the six portions 11c, making it rotatable.

Note that 13.13 is a width regulating plate that regulates the width setting position of the sheet S.

The upright surface near the center of the inside front of the housing l1 is the reference surface 11A.
, and forms part of the abutment surface of the sheet bundle. A square hole LIE bored from the center of the reference surface 11A to the bottom surface of the housing 11 allows the push-up lever 4 and the tip member 5 to
is an opening that can be passed through during swinging.

Rib-shaped abutment reference surfaces 110 and IID are integrally provided on both sides of the reference surface IIA on the inner front surface of the casing 11. The abutment reference surface 11D has a substantially upright plane 110a above the vicinity of the same height as the hole 11c of the both side walls, and has an inclined surface 11 such as a cylindrical curved surface or an inclined plane below it.
It forms Db. This inclined surface 11Db
The tip surface portion 12 of the load mounting plate l2 that is fitted into C and oscillates.
It has a surface shape that is almost similar to the swing locus drawn by A.

A large number of sheets S are stacked, housed, and aligned in the casing 11 of the large-capacity paper feed cassette that can accommodate 500 to 1000 sheets.

Next, when this paper feed cassette is installed in the inclined cassette loading section IO in the recording apparatus, the leading edge of the sheet S comes into contact with the abutment reference surface 11D. Almost at the same time as this cassette installation is completed, a push-up lever 4 and a tip member 5 are installed on the recording device side.
is operated counterclockwise around the rotating shaft 3 by the driving force from the driving source, and the housing 11 of the paper feed cassette is rotated.
The sheet mounting plate 12 is pushed up through the square hole 11E on the bottom of the plate, and is swung and tilted clockwise about the rotation fulcrum shaft portion 12B.

During this swinging, the leading end surface portion 12A of the sheet placing plate l2 and the leading end portion of the sheet bundle S move upward while drawing an arcuate locus as indicated by the arrow in FIG. Since this trajectory is almost the same as the shape of the abutting reference surface, the sheets S stacked on the sheet placing plate 12 are pushed back from the abutting reference surface 11D when the sheet placing plate l2 rises. It is driven upward with a light load without causing surface friction between the two parts. Then, the uppermost surface of the sheet bundle is pressed against the feed roller 6 with an appropriate pressing force P to prepare for feeding out the uppermost sheet S.

When a paper feed signal is input, the feed roller 6 is driven and rotated to feed out the sheet S in the vicinity of the uppermost layer, and then the uppermost sheet is separated by the so-called sorting action of the separating roller 7 and the double-feed prevention roller 8, which are driven and rotated. Only one sheet of S is fed to the recording section.

The subsequent sheet S is continuously fed out and placed on the sheet placement plate l.
When the number of sheets stacked on the cart 2 decreases, the push-up lever 4 is driven and rotated by the amount of the decrease, pushing up the sheet a placing plate l2 so that the topmost sheet S is always placed on the circumferential surface of the feed roller 6. They are pressed together with a pressing force P of . As the sheet placement plate 12 rises, the leading end of the bundle of sheets rises along the inclined surface 11Db of the abutting reference surface 11D, drawing the aforementioned arcuate locus. Therefore, in the process of raising or lowering the belt, the sheet S is not blocked by the abutment reference surface LID and pushed back, and is smoothly supplied to the delivery position with a light load.

Note that in this example, a relatively small size sheet S
1For example, B5 size (length 182mm), A4 size (length 210mm), letter size (length 216mm),
B5 size R (length 257m''in)',' A4 size R
(Length 297mm), Letter size R (Length 279mm)
) etc., since the rotation fulcrum shaft portion 12B and the tip portion 12A of the sheet placement plate 12 are relatively short, the arc radius of the aforementioned trajectory is small, and the abutting reference surface 11D has an inclined surface 11D.
The effect of providing b is significant.

〔Effect of the invention〕

The present invention is excellent in reducing the upward pressing driving force of the sheet placement plate in a large-capacity paper feed cassette that can accommodate a large amount of sheets, and in solving paper feeding failures due to uneven sheets on the sheet placement plate. be effective.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a large-capacity paper feed cassette according to the present invention and the paper feed section of a recording device, FIG. 2 is an exploded perspective view of the paper feed cassette, and FIGS. 3 and 4 are conventional paper feed cassettes. FIG. 4... Push-up lever 5... Tip member 6... Feeding roller lO... Cassette loading section 11... Housing llD... Abutting reference surface l2... Sheet mounting plate 12B. ...Rotation fulcrum shaft S...Seat 11A...Reference surface 11Db...Slanted surface 12A...Tip portion 12c...Arm portion

Claims (1)

[Claims] In a large-capacity paper feed cassette in which a rotatable sheet placement plate is provided in a paper feed cassette housing capable of accommodating a large amount of sheets, a sheet protrusion having a shape similar to the rotation locus of the tip of the sheet placement plate is provided. A large-capacity paper feed cassette, characterized in that a contact reference surface is formed within the paper feed cassette housing.