JPS5928989Y2 - Automatic paper feeding devices such as copying machines - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to automatic paper feeding devices such as copying machines.

Here, copying machines, etc. refer to, for example, electrophotographic and other types of copying machines, simple printing machines, facsimile IJs, etc.; Store the photosensitive paper, transfer paper, or printing paper, etc., and press the button.
A device that has the function of automatically feeding the paper to a processing section.

As a conventionally known automatic paper feeder, there is one shown in FIG. 1, for example.

In the figure, numeral 1 is a cassette case, numeral 2 (/'i
Bottom plate, reference numeral 3 is a fulcrum supporting the bottom plate 2, reference numeral 4 is a weight, reference numeral 5 is a paper feed roller, reference numeral 6 is L/i cassette case 1
Separation claws integrally formed at the front end of the paper, the reference numeral S, respectively indicate the paper to be fed.

In this example, as the paper S decreases, the bottom plate 2 is tilted, the paper S is pressed against the separating claw 6, and the paper feed roller 5 in the fixed position is
We are trying to keep the paper feeding conditions constant.

However, as the remaining amount of paper S decreases, the contact angle α between the separating claw 6 and the upper surface of the paper S changes greatly (see FIG. 2), making it difficult to obtain stable paper feeding performance.

Also, as the bottom plate 2 is tilted, there is a gap between the left front end of the bottom plate 2 and the front wall of the cassette case, and the paper S hanging on the separation claw 6 is
In order to prevent the area from decreasing, the right rear end of the bottom plate 2 is bent upward into an L-shape and pressed against the rear wall of the cassette case, so that the bottom plate 2 is pushed forward as the bottom plate 2 inclines. However, with such a longitudinal position correction means, it is difficult to obtain a predetermined constant pressure of the paper S against the separating claw 6 due to the influence of unstable frictional resistance at the pressure contact portion.

Furthermore, since the height of the fulcrum 3 remains unchanged, the depth of the cassette case 1 needs to be dimensioned to compensate for the thickness of a predetermined number of stacked sheets of paper S, which poses a problem in terms of volumetric efficiency.

It is an object of the present invention to provide an automatic paper feeding device such as a copying machine that solves the above-mentioned problems of the prior art.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 3, reference numeral 7 indicates a cassette case shaped like a single-bottomed box.

The cassette case 7 is configured to be removably inserted into a predetermined position on a step portion 8a and a base portion 8b that are integral with a main body (hereinafter referred to as a fixed member) of a copying machine or the like.

In the following figures, the left side is the paper feeding direction, and is also referred to as the front.

The right side is also referred to as the rear.

To install the above, attach the front end of the cassette case 7 to the step 8.
This is done by elastically pressing the rear end of the cassette case 7 with a spring 9 so as to press it against a.

Therefore, even cassette cases of different sizes can be stably held.

Separation claws 10 are provided on both sides of the upper front end of the cassette case 7.

As shown in FIG. 4, the separation claw 10 is formed integrally with an arm 11, and the end of the arm 11 is pivotally supported on the side of the cassette case 7.

In addition, in FIG. 3, only one side portion is shown.

The bottom plate 12 is housed inside the cassette case γ without any special fixing means.

As shown in Fig. 7, the bottom plate 12 is approximately L when viewed from the side beam.
It is shaped like a letter, and the paper S is placed on the horizontal part.

A weight 13 is provided on the rear wall portion of the bottom plate 12.

Further, a protrusion 14 is formed on the lower surface of the rear end of the bottom plate 12.

Two protrusions 15a and 15b are formed at the center of the lower surface of the bottom plate 12 at an interval.

The portion of the cassette case 7 that corresponds to the protrusion 14 is hollowed out sufficiently thicker than the protrusion 14, and the contact operating piece 17a of the microswitch 17 is engaged with the protrusion 14 that passes through the cutout 16 and projects. It is designed to match.

Among them, the microswitch 17 is fixed integrally with the immovable member.

An opening 18 is formed in the front half of the bottom of the cassette case 7.

The rear end of this opening 18 is formed to be slightly thicker, and forms a receiving part 20 for receiving the bottom plate lifting arm 19.

The bottom plate lifting arm 19 is a rod with one end bent upward, and the other end is fitted into the first arm 21a of the rotating piece 21 via an extensible spring 22 so as to be swingable.

A rotating piece 21t/'i, a second arm 21 which is pivotally supported on a shaft 23 integral with the immovable member and is a part of the rotating piece 21;
A counterclockwise rotational force is constantly applied by a tension spring 24 pulling the end of b.

Now, the bottom plate lifting arm 19 is moved by the action of the spring 22.
Although it is always in a state of being pushed out from the first arm 21a, this sliding movement due to this habit is prevented by the bottom plate lifting arm 19 coming into contact with the receiving portion 20.

Also, at the same time, the bottom plate lifting arm 19 together with the rotating piece 21,
As described above, a rotational force is applied in the counterclockwise direction, but the rotation due to this rotational force is caused by the ridgeline part formed at the tip of the bottom plate lifting arm 19 extending in the direction penetrating the plane of the drawing of the bottom plate 12. There is a case where the rotational force is prevented by coming into contact with the surface between the protrusions 15a and 15b formed on the lower surface and balancing the rotational moment acting in a clockwise direction with the press contact point between the paper feed roller 31 and the paper S as a fulcrum. In some cases, the locking pawl 26a engages with the teeth 25a of the ratchet wheel 25, which is substantially integrated with the rotating piece 21, thereby preventing the locking.

The cases in which these two cases arise will be understood later in the explanation of the effects.

The locking pawl 26a is formed in the middle of the lever 26, and the lever 26 itself is pivotally supported by a shaft 2γ that is integral with a stationary member that passes through the left side of the locking pawl 26a. There is.

The left end of the lever 26 is constantly pulled by the tension spring 28, and the engagement between the teeth 25a and the locking pawl 26a tends to be disengaged at all times.

On the other hand, the right end of the lever 26 is connected to a solenoid 30 via a wire 29.

The solenoid 30 is fixed to a stationary member and is supported by a spring 28.
The right end of the lever 26 is pulled up against the force of , or released from the pulled up state.

The solenoid 30 is electrically actuated and is actuated when voltage is applied to pull up the right end of the lever 26 and remove the tooth 25.
a and the locking pawl 26a are brought into engagement.

When the voltage application is cut off, the force of the spring 28 causes the shaft 2 to
The lever 26 is rotated clockwise about 7 as a fulcrum, and the engagement is released.

Opening and closing control of the voltage applied to the solenoid 30 is performed by a normally closed microswitch 17, as shown in FIG.

Next, the contact point (fulcrum) between the bottom plate lifting arm 19 and the bottom plate 12
At the front and above the bottom plate 12, a rotatable paper feed roller 31 attached to an immovable member is provided.

The paper feed roller 3 has the function of rotating in the direction of the arrow during paper feeding and feeding the paper S forward one sheet at a time.

The above-mentioned micro switch 17, rotary piece 21° ratchet wheel 25, lever 26, solenoid 30, and their attached members raise the bottom plate lifting arm 19 in accordance with the decrease in paper S as it is fed. It constitutes a means for raising the arm.

This arm lifting means is such that the pressing force of the paper S placed on the bottom plate 12 against the paper feed roller 31 is constantly maintained by the weight, regardless of the decrease in paper S due to paper feeding to the copying machine, etc. It has the function of raising the bottom plate lifting arm 19 in stages so that it acts as a substantially constant pressure depending on the size of the housing.

Next, the operation of the automatic paper feeder according to the present invention will be explained.

(1) Initial state (see FIG. 3) The bottom plate 12 on which a predetermined amount of paper S is placed is stored in the cassette case 7.

Then, the cassette case 7 is attached to the stepped portion 8a and the base portion 8b.

At step 1, when this installation is completed, the microswitch 17 is attached to the protrusion 14.
The contact actuating piece 17a is pressed into the open state by any other appropriate means.

Therefore, the solenoid 30 is also in an open state, and the tooth 2
5a and the locking pawl 26a are disengaged.

When the installation is completed, the bottom plate lifting arm 19 is guided by the force of the spring 22 in contact with the receiving part 20, so that the tip is positioned so as to correspond between the protrusions 15a and isb. Furthermore, this bottom plate raising arm 19
The uppermost surface of the paper feed roller 31 pushes up the bottom plate 12 at 1.

Therefore, the bottom plate 12 is able to swing freely using the tip of the bottom plate lifting arm 19 as a fulcrum, and the weight 13 is effective, so that the pressing force of the paper S against the paper feed roller 31 is fixed.

At this time, the lower surface of the separating claw 10 is in close contact with the upper surface of the paper S under its own weight, and the contact angle α (see FIG. 2) is 0°.

When the mounting of the cassette case T is completed in this manner, the microswitch 17 is brought into a closed state by releasing the appropriate means described above.

The above-mentioned closed state means that the contact operating piece 17a and the protrusion 14 are in a separated state.

For this reason, the solenoid is also closed, the teeth 25a and the locking claws 25a are engaged, and the height of the bottom plate lifting arm 19 as a fulcrum supporting the bottom plate 12 (hereinafter referred to as fulcrum height) is maintained. .

The height of the fulcrum at which the initial state is reached is the minimum height at which the bottom plate 12 can freely swing, which is also the minimum height at which the weight 13 functions.

FIG. 3 shows a state in which the above preparation steps have been completed.

(2) Paper feeding status (see Figures 3 and 6).

The paper feed roller 31 is rotated in the direction of the arrow to feed the paper and feed the paper S(/'i) forward one by one.

In this way, as the paper on the bottom plate 12 decreases, the bottom plate 12 tilts downward to the right.

When the bottom plate 12 interferes with the bottom of the cassette case 7, the weight 13 becomes ineffective and the pressure force between the paper feed roller 31 and the paper S fluctuates, so at least before the interference occurs,
The protrusion 14 presses the contact operating piece 17a to open the microswitch 17.

Then, the teeth 25a and the locking pawl 26a are disengaged, and the teeth 25a of the ratchet wheel 25 are advanced until the protrusion 14 and the contact operating piece 17a are separated, and the bottom plate lifting arm 19 lifts the bottom plate 12 with the weight 13. Push up with a lever to a height that is effective,
When the protrusion 14 and the contact actuation piece 17a are separated, the microswitch 17 is closed, and the solenoid 30 is closed.
works, and at this fulcrum height of 11, the tooth 25a and the locking pawl 2
6a and maintains the fulcrum height.

In this manner, the bottom plate 12 is raised stepwise by the arm raising means in accordance with the decrease in paper due to paper feeding, and the pressure of the paper against the paper feed roller 31 is controlled to an appropriate value.

FIG. 6 shows a state in which the paper S on the bottom plate 12 has decreased considerably, the protrusion 14 presses the contact operating piece 17a to open the microswitch 11, and the fulcrum height of the bottom plate lifting arm 19 is fixed. This shows the state immediately after one.

In this way, when the remaining amount of paper S decreases, the bottom plate 12 tilts considerably, but the fulcrum position of the bottom plate 12 does not shift because the protrusions 15a and 15b prevent the tip of the bottom plate lifting arm 19 from slipping.

Therefore, regardless of the decrease in paper S, the height of the fulcrum at which the weight 13 is applied is updated appropriately, and in the process, the paper feed roller 3
The pressure force between the paper S and the paper S is always set to an appropriate value.

Further, as shown in FIG. 6, as the bottom plate 12 inclines, the separation claw 10 rotates clockwise around the pivot point at the tip of the arm 11 while contacting the paper S. The tangent angle α (see FIG. 2) is maintained at almost 0°, and the area of the paper S that is applied to the separating claw 10 does not decrease as the number of papers decreases.

In addition to the above-mentioned effects, in the present invention, since the height of the fulcrum of the bottom plate 12 is raised, the depth of the cassette case 7 need only be slightly more careful than the thickness of the predetermined number of sheets. It has the advantage of volumetric efficiency since it does not require space like the prior art.

[Brief explanation of drawings]

Figure 1 is a vertical sectional view of an automatic paper feeder according to the prior art;
The figure is an enlarged view of the separating claw part, FIG. 3 is a longitudinal cross-sectional view of the automatic paper feeder according to the present invention in its initial operating state, FIG. 4 is a perspective view of the separating claw, and FIG. 5 is a microswitch and solenoid. FIG. 6 is a longitudinal sectional view of the automatic paper feeder according to the present invention, which can be pressed when the remaining amount of paper is reduced, and FIG. 7 is a perspective view of the bottom plate. γ...Cassette case, 10...Separation claw, 12...Bottom plate, 13...Weight, 1
8... Opening portion, 19... Bottom plate lifting arm, 20... Receiving portion, 31... Paper feed roller.

Claims (1)

[Scope of Claim for Utility Model Registration] A box-shaped cassette case for paper supply that is removably installed in a predetermined position of a copying machine, etc. and has swingable separation claws on both sides of the upper front end; It is stored without any fixing means, and passes through the bottom plate for placing paper, which has a weight attached to the rear wall, and the opening formed at the bottom of the cassette case.
and a bottom plate lifting arm that is guided by a receiving part at the rear end of the opening and comes into contact with approximately the center of the bottom plate to swingably support the bottom plate, and a contact point (fulcrum point) between the bottom plate lifting arm and the bottom plate in front of There it is,
Automatic paper feeding in a copying machine, etc., which has a rotatable paper feeding roller provided above the bottom plate, and arm lifting means that raises the bottom plate lifting arm step by step as the amount of paper decreases. Device.