JP2000062971A - Paper feeding cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a push-up plate from being raised rapidly even if locking of the push-up plate is released at the time of installation on a device body. SOLUTION: This sheet feeding cassette 20 is provided with a means 35 which energizes upwards a push-up plate 26 placing paper inside the paper feeding cassette 20, locks the push-up plate 26 at a lower position at the time of setting paper, and releases locking of the push-up plate 26 by fitting the paper feeding cassette 20 into a device body. This cassette is also provided with a damper mechanism 7 which controls rising speed of the push-up plate 26 after locking of the push-up plate 26 is released by inserting the paper feeding cassette 20 into the device body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding cassette arranged in a sheet feeding portion of an image forming apparatus, and more particularly to a sheet feeding cassette capable of swinging a push-up plate on which a large number of sheets are placed in a stable state. It is about.

[0002]

2. Description of the Related Art In an image forming apparatus such as a facsimile machine, a copying machine, a printer, etc., a paper feed cassette is attached to a paper feed section of the main body of the apparatus, and the paper is fed from the paper feed cassette toward an image recording section. , Is configured to form an image on recording paper. For a device that feeds paper using a paper feed cassette, place the paper on the push-up plate that is biased upward by the push-up spring inside the paper feed cassette while the paper feed cassette is set in the paper feed section of the main body of the device. Then, a mechanism for pushing up the sheet toward the sheet feeding roller via the push-up plate is provided. Then, the uppermost one of the sheets is brought into contact with the sheet feeding roller with a predetermined pressing force, and the sheet feeding roller is rotated to feed the sheets one by one.

Further, in the paper feed cassette, means for fixing the push-up plate in a depressed position for accommodating the paper is provided, and the push-up plate is fixed by the operation of inserting the paper feed cassette into the paper feed section of the apparatus main body. Automatically release,
A mechanism for swinging the push-up plate upward by a push-up spring is provided. Therefore, in a general paper feed cassette, it is possible to easily perform the replenishment of paper to the paper feed cassette and the work of mounting the paper in the paper feed unit of the image forming apparatus.

[0004]

In the conventionally used paper feed cassette, for example, the paper storage capacity is 50.
For those having zero or more performances, it is required to use, as a push-up spring for biasing the push-up plate upward, one having a strong elastic force capable of bearing the weight of the sheet. However, with a paper feed cassette that uses a strong push-up spring, when releasing the lock on the push-up plate,
Since the push-up plate is suddenly pushed up by the push-up spring, a large amount of noise may be generated. In addition, when a small number of sheets of paper are accommodated in the paper feed cassette and mounted in the paper feed unit, the amount of movement of the push-up plate increases, which causes a problem that noise and impact become extremely large. The sudden rise of the push-up plate is likely to cause inconveniences such as breakage of the snubber claws.

An object of the present invention is to solve the above-described problems of the conventional sheet feeding cassette, and even if the fixing of the pushing plate is released when the sheet feeding cassette is mounted, the pushing plate is rapidly raised. It is to provide a paper feed cassette provided with a mechanism that does not prevent it.

[0006]

In order to achieve the above-mentioned object, the invention of claim 1 of the present invention urges a push-up plate for placing a paper sheet in a paper feed cassette in an upward direction, and In the paper feed cassette provided with a means for releasing the lock of the push-up plate by locking the push-up plate in the lower position when mounting and mounting the paper feed cassette in the device main body, A damper mechanism for controlling the rising speed of the push-up plate was provided after the lock-up of the push-up plate was released by inserting it into the. Further, in the invention of claim 2, the damper mechanism is a rotary damper provided on the push-up plate, and the rotary damper is provided with a gear that receives resistance to rotation in only one direction. It meshed with the rack installed on the. Further, in the invention of claim 3, the damper mechanism is a rotary damper fixed to the paper feeding cassette, and the rotary damper is provided with a gear that receives resistance to rotation in only one direction, and pushes up the gear. It meshed with the gear provided on the plate.

By virtue of the above-mentioned construction, in the present invention, a small number of sheets are loaded in the paper feed cassette constituted by means for raising the push-up plate by using the push-up spring having a large elastic force. Even when the cassette is set in the paper feed unit, it is possible to slowly raise the push-up plate and bring the paper into contact with a paper feed member such as a paper feed roller. And by not raising the paper suddenly,
The snubber claw and other members are not impacted, and a stable paper feeding operation can be performed by mounting the paper feeding cassette. In addition, by setting the rising speed of the push-up plate to a low speed, noise or the like when the lock of the push-up plate is released does not occur.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A sheet feeding cassette according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an image forming apparatus equipped with a sheet feeding cassette of the present invention. FIG. 2 is a central vertical cross-sectional view showing the paper feed cassette according to the first embodiment of this invention. FIG. 3 is a perspective view showing the entire paper feed cassette of FIG. FIG. 4 is a sectional view taken along line AA in FIG. Figure 5
It is explanatory drawing which shows the relationship between a push-up plate and a locking member.
FIG. 6 is a plan view showing the relationship between the push-up plate and the locking member. FIG. 7 is a central vertical cross-sectional view showing the paper feed cassette according to the second embodiment.

The image forming apparatus 1 shown in FIG. 1 is configured as a facsimile apparatus, and an original hopper 15 for setting an original and an original tray 16 for accommodating the read original are provided on an upper portion of a main body frame 2. Are arranged. An apparatus (not shown) for forming an image on a recording sheet is arranged inside the main body frame 2, and a sheet feeding section 3 for feeding a sheet toward an image forming section is provided at a lower portion of the apparatus. . A paper feed cassette 20 is attached to the paper feed unit 3, and a paper feed roller 10 for feeding paper from the paper feed cassette 20 is provided.
Paper transport path 1 for guiding the paper toward the image forming unit
1 and are arranged. Further, a cassette guide 6 for guiding the protruding member 24 of the paper feed cassette 20 in the insertion direction is provided on the inner surface of the frame side plate 5.

In the paper feed cassette 20, as shown in FIGS. 1 and 3, the rear end of the push-up plate 26 on which the paper P is placed is supported by a hinge 29 inside the side wall 23, and the tip of the push-up plate is supported. A push-up spring 30 for raising the sheet is provided below the leading end of the sheet feeding side. And push-up spring 3
0, the uppermost sheet supported by the push-up plate is provided so as to come into contact with the sheet feeding roller 10 with a predetermined pressing force. The paper feed cassette 20 has a handle 21
The paper feed cassette 20 is attached to the paper feed unit of the image forming apparatus in the arrow X direction, and the paper is fed out from the paper feed cassette 20 in the arrow Y direction.

FIG. 4 is a sectional view of the paper feed cassette 20 as seen from the paper feed direction. Snubber claws 31 and 31 are arranged at the leading end of the sheet P placed on the push-up plate 26 on the feed-out side to perform a sheet separating action (note that the snubber claw 31 is omitted in FIG. 3). Further, during paper supply, the push-up plate 26 of the paper feed cassette 20 is fixed at the most lowered position. After pulling out the paper feed cassette 20 from the paper feed unit, the push-up plate 26 is lowered, and the lower claw member 28 provided so as to project below the push-up plate 26 is provided.
Is pushed into the claw insertion hole 36 of the locking member 35 and locked, so that the push-up plate 26 is fixed.

When the push-up plate 26 is fixed in the lowered position and the push-up plate 26 is unlocked when the paper feed cassette 20 is inserted into the paper feed section, a locking handle as shown in FIG. Has throws. In order to lock the lower claw member 28 of the push-up plate 26, the locking member 35 provided with the claw insertion hole 36 is arranged as described above. The locking member 35 has a guide slope 37 at one end of the claw insertion hole 36. By pressing the push-up plate 26 from above, the lower claw member 28
Can be inserted into the claw insertion hole 36, the projection of the lower claw member 28 is locked to the lower surface of the locking member 35,
It is fixedly held in the lowered position.

The locking member 35 is provided so as to be movable in the paper feeding direction. By moving the locking member 35 to the left side of the paper surface of FIG. 5, the lower claw member in the claw insertion hole 36 is moved. The lock of 28 is released, and the push-up spring 30 raises the push-up plate 26.

When the push-up plate 26 is lowered after the paper feed cassette 20 is pulled out from the paper feed section, the lower claw member 28 is moved slightly by moving the locking member 35 toward the right side in the drawing. Can be locked and fixed to the locking member 35.

The relationship between the push-up plate 26 arranged in the paper feed cassette 20 and the locking member can be configured as shown in FIG. 6, and a claw insertion hole is formed at the center of the locking member 35 having a substantially triangular shape. 36, and projections 39, 39 projecting outward from the side wall 23 of the cassette are arranged on both sides. Also,
Members acting on the protrusions 39, 39 (not shown)
Is provided on the main body frame 2 side, and the locking member 35 is moved toward the paper feeding direction during the operation of mounting the paper feeding cassette 20 in the paper feeding portion, so that the push-up plate 26 is locked. Release it.

The paper feed cassette 20 can be configured to accommodate an arbitrary number of paper sheets, but in the present invention, the paper feed cassette 20 is configured to accommodate about 1000 paper sheets, Push up a large amount of paper 2
The force of the push-up spring 30 is set so that the push-up plate 26 can be raised in the state where the push-up plate 26 is placed.

Therefore, since the force of the push-up spring is much stronger than that of the conventional paper feed cassette capable of storing about 250 sheets, when the paper feed cassette 20 is set in the paper feed section. In addition, when the locking of the push-up plate 26 is released, the action of rapidly raising the push-up plate 26 is generated by the force of the push-up spring, and in the conventional case, the impact at that time is extremely large.

Therefore, a control means for controlling the rising speed of the push-up plate 26 is provided. In the paper feed cassette of the present invention, the rotary damper 7 is provided as a damper mechanism. As shown in FIG. 2, a bent portion 27 is provided on the tip side of the push-up plate 26. The bending damper 27 is provided with the rotary damper 7. The peripheral surface of the rotary damper 7 is a gear portion 7a.

The gear portion 7a of the rotary damper 7 is shown in FIG.
It is rotatable in the counterclockwise direction. However, there is a damper action in the clockwise direction in FIG. 2 so that the damper rotates slowly even when a sudden torque is applied. Further, a rack gear 25 is provided on the side wall 23 of the paper feed cassette 20,
The gear portion of the rack gear 25 and the gear portion 7a of the rotary damper 7 mesh with each other.

Since the rotary damper 7 is constructed as described above, when the push-up plate 26 is lowered, the push-up plate 26 is pushed down by a normal downward force against the elastic force of the push-up spring 30. However, when the push-up plate 26 rises, the elastic force of the push-up spring 30 is attenuated by the action of the rotary damper 7, and the push-up plate 26 slowly rises. Therefore, the impact sound of the push-up plate 26 can be prevented, and the snubber claw 31 is not damaged.

FIG. 7 shows a second embodiment.
As shown in FIG. 7, the supporting piece 27 a supporting the hinge 29 portion of the push-up plate 26 is provided with a gear portion 25 a centering on the hinge 29. Support piece 27a and gear portion 2
5a is integrated and rotates about a hinge 29.

A rotary damper 7 is attached to the side wall 23 of the paper feed cassette 20. The peripheral surface of the rotary damper 7 is a gear portion 7a. The gear portion 7a of the rotary damper 7 is rotatable counterclockwise in FIG. However, there is a damper action in the clockwise direction in FIG. 7, so that it rotates slowly even when a sudden torque is applied.

The gear portion 25a of the push-up plate 26 described above.
And the gear portion 7a of the rotary damper 7 meshes with each other. Since the rotary damper 7 is configured in this way, when lowering the push-up plate 26, the push-up spring 30
It is pushed down at a normal descending speed that resists the elastic force of.

However, when the push-up plate 26 rises, the elastic force of the push-up spring 30 is attenuated by the action of the rotary damper 7, and the push-up plate 26 slowly rises. Therefore, the impact sound of the push-up plate 26 can be prevented, and the snubber claw 31 is not damaged.

If the rotary damper 7 is provided symmetrically in the X direction in FIG. 3, the rising speed can be controlled in a well-balanced manner without twisting the tip side of the push-up plate 26.

Paper feed cassette 2 constructed as described above
Even if the push-up plate 26 is unlocked when the push-up plate 26 is inserted into the paper feed section of the image forming apparatus, the push-up plate 0 is irrelevant to the amount of sheets stored on the push-up plate 26 of the paper feed cassette 20. 26 will rise at a reasonable rate. That is, the push-up plate 26 does not rise rapidly, and the impact at that time is not large.

[0027]

As described above, according to the present invention, a small number of sheets are attached to the paper feed cassette constituted by the means for raising the push-up plate by using the push-up spring having a large elastic force, and the main body of the apparatus is fed. Even when the paper feed cassette is set in the paper unit, it is possible to slowly raise the push-up plate and bring the paper into contact with a paper feed member such as a paper feed roller. And by not raising the paper abruptly, there is no impact on the snubber claws and other members,
A stable paper feeding operation can be performed by mounting the paper feeding cassette. Further, by setting the rising speed of the push-up plate to a low speed, noise or the like when the push-up plate is unlocked does not occur.

[Brief description of drawings]

FIG. 1 is a front view showing an image forming apparatus equipped with a paper feed cassette of the present invention.

FIG. 2 is a central vertical cross-sectional view showing the paper feed cassette according to the first embodiment of this invention.

FIG. 3 is a perspective view showing the entire paper feed cassette of FIG.

FIG. 4 is a sectional view of the sheet feeding cassette taken along the line AA in FIG.

FIG. 5 is an explanatory diagram showing a relationship between a push-up plate and a locking member.

FIG. 6 is a plan view showing a relationship between a push-up plate and a locking member.

FIG. 7 is a central longitudinal sectional view showing a paper feeding cassette according to a second embodiment.

[Explanation of symbols]

1 Image forming device 3 paper feeder 7 Rotary damper (damper mechanism) 20 paper cassettes 26 Push-up plate 30 push-up spring 35 locking claw

Claims (3)

[Claims] 1. A paper feed cassette in which the paper is loaded, the push-up plate is placed in the paper feed cassette, and the push-up plate is locked in the lower position when the paper is loaded. In the paper feed cassette provided with means for unlocking the push-up plate by mounting the lock on the push-up plate, the damper that controls the rising speed of the push-up plate after the lock of the push-up plate is released by inserting the paper feed cassette into the apparatus main body. A paper feed cassette characterized by having a mechanism. 2. The damper mechanism is a rotary damper provided on a push-up plate, and the rotary damper is provided with a gear that receives resistance to rotation in only one direction, and the gear is provided in a paper feed cassette. The paper feed cassette according to claim 1, wherein the paper feed cassette engages with a rack. 3. The damper mechanism is a rotary damper fixed to a paper feed cassette, and the rotary damper is provided with a gear that receives resistance to rotation in only one direction, and the gear is provided on a push-up plate. The sheet feeding cassette according to claim 1, wherein the sheet feeding cassette meshes with a gear portion.