JPH02295828A - Paper feeding device - Google Patents

Abstract

PURPOSE:To raise and fall a movable bottom plate easily and secularly in response to a disconnection of a paper feeding cassette by providing a press means for energizing a force lever, which oscillates and lifts charts in a paper feeding cassette to the predetermined position, to the upper direction. CONSTITUTION:When a cassette 10 is mounted, the inclined part of a cam surface 13 of a cassette main frame 11 side surface abuts on a projection 27A of an oscillating lever 27, and the oscillating lever 27 is turned in the clockwise around of a fixed supporting shaft 26. At the same time, an arm member 29 connected to the oscillating lever 27 through a coil spring 30 is turned in the counterclockwise with an oscillating shaft 28. A force lever 25 fixed on the oscillating shaft 28 is turned in the counterclockwise to push up a movable bottom plate 12. Wen the top layer of a chart bundle P loaded on the top face of the movable bottom plate 12 reaches the condition that it is in a pressure- contact with the peripheral surface of a feeding roller 22, the tip 37a of a braking are member 37 is engaged with a gear of a ratchet 33 to prevent and stop the rotation of the ratchet 33.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a paper feeding device in a recording device such as a copying machine, a printer, or a light printing machine, and in particular, the present invention relates to a paper feeding device in a recording device such as a copying machine, a printer, or a light printing machine. The present invention relates to a paper feeding device that is removably installed in a stage.

[Conventional technology]

Conventionally, in recording devices such as copying machines, a paper feed system has been used to sequentially take out sheets of paper stored in a stack in a paper tray, paper feed cassette, paper stacker, etc., one by one, starting from the top, and send them to an image recording unit, etc. Equipment is provided.

For the upper paper feed cassette, a corner separation method using separation claws, a friction separation roller method, etc. are generally used.

The paper feeding device disclosed in Japanese Patent Application Laid-Open No. 63-33865 uses a corner separator system using separation claws.

FIG. 4 is a sectional view showing an example of a paper feeding device using this separating claw. As shown in the figure, the top layer of sheets P stacked and placed on the movable bottom plate 2 in the paper feed cassette I-1 is
The bottom plate is pressed against the circumferential surface of the feed roller 4 by the spring biasing force of the coil spring 3 for pushing up the bottom plate. Separation claws are placed on both corners of the leading end of the sheet bundle P in the feeding direction, and when the sheets are fed out by rotation of the feed roller, the uppermost layer of paper buckles at the separation claw portion and is pulled out from the separation claw.

FIG. 5 is a cross-sectional view of a paper feeding device using double feeding prevention rollers. This is equipped with a feed roller 6 that presses against the sheet bundle instead of the feed roller 4, and a feed roller 7A and a reverse roller 7B for preventing double feeding. In this type of paper feeding device, the feed roller 6 located at a fixed position serves as an upper limit stopper for the paper bundle P, and the paper bundle P is pressed by the biasing force of the coil spring 3. By detecting the paper upper limit and controlling the motor drive, the movable bottom plate is moved up and down to enable paper feeding, paper replenishment, cassette replacement, and the like.

FIG. 6 is a cross-sectional view of a paper feeding device that has improved the drawbacks of the above two systems, in which the coil spring 3 is eliminated and the movable bottom plate 2 is pushed up by the driving force of the motor M via the gears Gl and G2, and the plate 8 is fixed. The movable bottom plate 2 is moved up and down by rotating the swing shaft 8A. Then, the motor M is driven and rotated until the upper limit position (feeding position) of the paper bundle P is detected by a sensor such as the switch 9, so that the upper limit of the paper bundle P is always kept constant.

[Problem to be solved by the invention]

If the movable bottom plate 2 is lifted by being biased by the coil spring 3, the biasing force of the spring changes depending on the thickness of the stack of sheets, and a uniform pressing force cannot be obtained. However, the above spring biasing force is based on the weight of the paper stack loaded on the movable bottom plate, that is, the size of the paper (A6 size to A3 size).
paper size), number of sheets in the paper stack (1 to 500 sheets), paper weight (4
0 to 70 kg), it is difficult to support these various types of paper using spring biasing force and press it uniformly against the feed roller. In particular, when storing a large amount of paper in the paper feed cassette, the spring biasing force cannot cope with the problem.

To solve this problem, a means (see Fig. 6) for raising the movable bottom plate 2 by the driving force of the motor M has been put into practical use. Not only is the structure complicated and manufacturing costs high, but if the paper feed cassette is attached or detached during operation, accidents such as malfunction or damage may occur.

Further, according to a paper feeding device for a copying machine disclosed in Japanese Patent Application Laid-Open No. 48-104545, a switching device consisting of a cam plate or the like operated by a plurality of electromagnetic magnets is operated by a gear train from a single drive source. A mechanism switches the copy paper feed. However, such a switching mechanism consisting of magnets, cam plates, links, gears, etc. is not only extremely complicated, but also has problems in the stability and reliability of its operation.

Furthermore, the cassette paper feeding device disclosed in Japanese Utility Model Application No. 61-132342 detects the height of paper using a paper level sensor and operates a drive means to push up and swing the bottom plate. , the structure is complex.

[Means to solve the problem]

This invention eliminates the drawbacks of the conventional paper feeding device as described above, has a simple structure and reliable operation, prevents damage to the device, eliminates the need for operational precautions, and achieves normal paper feeding. The purpose is to provide a paper feeding device that can.

A paper feeding device of the present invention that achieves the above object is a paper feeding device in which a paper feeding cassette storing a plurality of sheets of recording paper is removably installed in a paper feeding section of a recording device. a push-up lever that swings and lifts the recording paper in the push-up lever to a predetermined position; a pushing means that urges the push-up lever upward; and a swing shaft of the push-up lever or a drive connection from the swing shaft. A brake wheel member fixed to a rotary shaft, and a brake wheel member that approaches and separates from the surface of the brake wheel member to restrict and restrict rotation of the brake wheel member.
The present invention is characterized in that it is composed of a brake arm member that releases the brake arm, and a detection member that is substantially integrated with the brake arm member and detects the upper limit position of the recording paper.

Further, the brake wheel member attached to the paper feeding device of the present invention is a ratchet wheel, and the ratchet wheel locking portion of the brake arm member is a non-return pawl member.

Furthermore, the object of the present invention can also be achieved by making the brake wheel member a friction wheel and making the friction wheel contact surface of the brake arm member a friction member.

[Effect]

When a paper feed cassette is loaded into the paper feed section of the recording apparatus main body, the pressing means is spring-biased in conjunction with the movement of the paper feed cassette main body, swings the push-up lever, and presses the movable bottom plate inside the paper feed cassette. is pushed upward, and the uppermost layer of the recording paper bundle on the movable bottom plate is brought into pressure contact with the circumferential surface of the feed roller and stopped.

When the top layer of the stack of recording paper on the movable bottom plate reaches the feed roller surface, the detection member that detects the upper limit position of the recording paper is pushed up, and the braking arm member that is integrated with the detection member swings. The tip portion contacts and locks the brake wheel member (ratchet wheel or friction wheel) to prevent rotation of the brake wheel member, thereby stopping the swinging of the push-up member.

When the recording paper on the movable bottom plate is fed out and decreases, the detection member descends together with the recording paper surface, the tip of the brake arm member separates from the brake wheel member, and the push-up member is pulled up by the spring biasing force, causing the movable bottom plate to Push up. As a result, the uppermost layer of the recording paper bundle comes into contact with the peripheral surface of the delivery roller and the detection member again, and at the same time, the brake arm member stops the rotation of the brake wheel member and the swinging of the movable bottom plate.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The paper feeding device of the present invention will be explained below using an embodiment of the paper feeding device shown in the accompanying drawings.

1 to 3 show an embodiment of a paper feeding device according to the present invention. Fig. 1 is a cross-sectional view showing a state in which a paper feed cassette is attached to the paper feed section of the main body of the recording apparatus; Figure 3 is a plan view thereof.

The paper feed cassette IO has a cassette main body 11 and a movable bottom plate 12.
It consists of A slanted cam surface 13 is integrally formed on the outer surface of the cassette body 11. Movable bottom plate 12
Paper P is placed on the upper surface side. One end of the movable bottom plate 12 is rotatably locked to a part of the bottom surface of the cassette body 11, and the other end is pressed against the circumferential surface of a feed roller 22, which will be described later, through the paper when the movable bottom plate 12 swings upward. do.

The paper feed section 20 on the side of the recording apparatus main body includes a paper feed tray 21 that stores the paper feed cassette 10 in a predetermined position and fixes it, and a paper feed roller section that includes a feed roller 22, a feed roller 23, a reverse roller 24, etc. It is composed of a drive section that moves the push-up lever 25 up and down. One end of a swing lever 27 is rotatably supported on a support shaft 26 on the side surface of the paper feed tray 21. A coil spring 30 is tensioned between the other end of the lever 27 and the tip of an arm member 29 fixed to a swing shaft 28 integrated with the push-up lever 25. is biased downward by a spring.

A protrusion 27A is fixed to a part of the lever 27, and when the paper feed cassette 1O is installed or removed, the swinging lever 27 swings by coming into contact with and separating from the cam surface 13 provided on the outer surface of the cassette main body 11. be moved.

The swing shaft 28 is supported by bearings 31, 31 and is swingable. The gear Gl fixed to the shaft end of the swing shaft 28 forms a speed increasing gear train that meshes with the gear G4 via the two-stage gears G 2 and G 3 of the intermediate shaft 32.

The gear G4 is coaxially connected to a brake wheel member (for example, a ratchet wheel).
33 are integrated, and both are fitted into a shaft 34 so as to be freely rotatable.

On the other hand, on the shaft of the feed roller 23, a bearing 35°3
A brake arm member 37 is fixed to the shaft end of a rotary shaft 36 rotatably supported by the brake arm member 37 . The brake arm member 3
The tip portion 37a of No. 7 is engaged with and released from the circumferential surface (ratchet teeth) of the brake wheel member 33 by swinging.

Further, a detection member (feeler) 38 is fixed to the other shaft end of the rotating shaft 36, and a tip portion 38 of the detection member 38
a contacts the surface of the recording paper P on the movable bottom plate 12.

Next, the operation process of the paper feed cassette that is inserted into and removed from the paper feed section in the recording apparatus as described above will be described below.

(1) First, the paper feed cassette 1° is mounted on the paper feed table 21 of the paper feed section 20 by sliding it in the direction of the arrow in FIG. FIG. 1 shows the complete installation state. When installing this cassette, the cassette body 1
The inclined portion of the cam surface 13 on one side abuts the protrusion 27A of the swing lever 27, and the swing lever 27 rotates clockwise about the fixed support shaft 26.

At the same time, the arm member 29 connected to the swing lever 27 via the coil spring 30 is rotated counterclockwise together with the swing shaft 28. The push-up lever 25 fixed to the swing shaft 28 also rotates counterclockwise to push up the movable bottom plate 12 (as indicated by the dotted chain arrow in FIG. 1).

As the swing shaft 28 rotates, the gear G1 fixed to the shaft end of the swing shaft 28 rotates the gear G2 fitted to the intermediate shaft 32, and further rotates the gear G4 via the gear G3. .

During the upward movement of the movable bottom plate 12, the distal end 37a of the brake arm member 37 is connected to the ratchet wheel 33 which is integrated with the gear G4.
Since the ratchet wheel 33 is separated and retracted from the teeth of the ratchet wheel 33, the ratchet wheel 33 is rotatable.

■ As the movable bottom plate 12 rises, the movable bottom plate 12
The top layer of the stack of recording sheets P stacked on the top surface of the detection member 3
As the brake arm member 37 contacts the tip 38a of the brake arm 37 and further pushes up the tip, the tip 37a of the brake arm member 37, which is substantially integrated with the detection section 38, approaches the teeth of the ratchet wheel 33.

(i) When the uppermost layer of the stack of recording sheets P loaded on the upper surface of the movable bottom plate 12 reaches a state in which it comes into pressure contact with the circumferential surface of the feed roller 22, the tip end 37a of the brake arm member 37 contacts the teeth of the ratchet wheel 33. The ratchet wheel 33 is engaged to prevent and stop the rotation of the ratchet wheel 33. As a result, the gear train and the swing shaft 28
rotation stops, and the push-up lever 25 stops while supporting the movable bottom plate 12 (see FIG. 1).

- When copying is started and the number of recording sheets P on the movable bottom plate 12 decreases, the tip 538a of the detection member 38 descends;
At the same time, the distal end 38a of the brake arm member 38 disengages from the teeth of the ratchet wheel 33, allowing it to rotate. As a result, the push-up lever 25 is moved to the movable bottom plate 1 via the gear train.
2 to press the recording paper P against the feed roller 22 and keep it in a state where it can be fed at all times. During paper feeding, as described above, the ratchet wheel 33 and the gear train are driven at appropriate times to keep the paper in a ready state at all times.

■ When replenishing the recording paper P or replacing it with another paper cassette, move the paper cassette lO on the paper feed table 21.
bring out. When the paper feed cassette 10 is pulled out, the cam surface 13 on the side of the cassette body 11 and the protrusion 2 of the swing lever 27
7A is released, the swing lever 27 swings downward, and the push-up lever 25 descends toward the bottom of the paper feed table 21. As the push-up lever 25 is lowered and the movable bottom plate 12 is lowered, the top surface of the recording paper stack P or the movable bottom plate 12 is separated from the circumferential surface of the feed roller 22, and the tip 38a of the detection lever 38 is moved. At the same time, the distal end portion 37a of the brake arm member 37 separates from the teeth of the ratchet wheel 33. This enables the ratchet wheel 33 and the gear train to rotate, and the push-up lever 25 is pressurized by its own weight and the weight of the movable bottom plate 12 and the stack of recording sheets P, and is buried and retreated below the paper feed table 21 ( (See Figure 2). From this state, by further pulling out the paper feed cassette 1O, recording paper can be replenished and replaced, and the paper feed cassette can be removed and replaced.

Although the embodiment of the paper feeding device described above operates the push-up lever by power transmission by a gear train, the present invention is not limited to this embodiment, and other power transmission means, such as transmission by sprockets and chains, may be used. It is also possible to use a transmission means such as a toothed belt or a toothed belt.

In addition, the braking means for stopping and releasing these power transmission means includes a friction wheel (such as a brake drum or a disc brake) in addition to a ratchet wheel as a braking wheel member, and an arm member having a friction sliding surface as a control arm member. It is also possible to use brake shoes (brake shoes, etc.).

〔Effect of the invention〕

As explained above, since the paper feeding device of the present invention has the above-described configuration and functions, the movable bottom plate can be easily and reliably raised and lowered in response to the attachment and detachment of the paper feeding cassette. Moreover, during paper feeding, the movable bottom plate is always pressed against the feed roller with a constant pressure in response to the decrease in the number of recording papers, so that paper feeding is performed reliably and stably.

Furthermore, the paper feeding device of the present invention has a simple structure, and has excellent durability and
It has excellent stability and is effective in reducing device size and component costs.

[Brief explanation of drawings]

1 to 3 show an embodiment of the paper feeding device according to the present invention, and FIG. 1 is a cross-sectional view of the paper feeding device showing a state in which a paper feeding cassette is attached to the paper feeding section of the recording apparatus main body, and FIG. Figure 2 is a cross-sectional view of the paper feeder with the paper feed cassette taken out from the paper feeder, Figure 3 is a plan view thereof, and Figures 4, 5, and 6 are cross-sectional views of the conventional paper feeder. . 10... Paper feed cassette 11... Cassette body 12... Movable bottom plate 13... Cam surface 20.
...Paper feed section 21...Paper feed tray 22...Feeding roller 23...Feed roller 24...
Reverse roller 25...Push lever 26...
Support shaft 27... Swing lever 27A...
Projection 28... Swing shaft 29... Arm member 30... Coil spring 32... Intermediate shaft 33... Braking wheel member 34... Shaft 37... Braking arm member 38... Detection Members G l , G 2 , G 3 , G P...paper (recording paper) (ratchet wheel) 36...rotating shaft 37a...tip part 38a...tip part 4...gear

Claims (3)

[Claims] (1) In a paper feed device in which a paper feed cassette loaded with multiple sheets of recording paper is removably installed in the paper feed section of a recording device, the recording paper in the paper feed cassette is swung to a predetermined position. a push-up lever for lifting the push-up lever, a pressing means for urging the push-up lever upward, and a brake wheel member fixed to a swing shaft of the push-up lever or a rotating shaft drivingly connected to the swing shaft. a brake arm member that approaches and separates from the circumferential surface of the brake wheel member to regulate and release the rotation of the brake wheel member; and a detection member that is substantially integrated with the brake arm member and detects the upper limit position of the recording paper. A paper feeding device comprising: (2) The paper feeding device according to claim 1, wherein the brake wheel member is a ratchet wheel, and the ratchet wheel locking portion of the brake arm member is a check pawl member. (3) The paper feeding device according to claim 1, wherein the brake wheel member is a friction wheel, and the friction wheel contact surface of the brake arm member is a friction member.