JP2661374B2 - Automatic paper feed mechanism - 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 feed mechanism for automatically and sequentially feeding paper in a printer, a copying machine, a facsimile machine, or the like.

[0002]

2. Description of the Related Art As shown in a schematic side sectional view of a main part of FIG. 2, a main component of a conventional automatic sheet feeding mechanism supports a sheet 1 to be loaded such as a cut sheet of a predetermined size and a cassette. A pressing plate 3 provided in the case 14 for bringing the upper surface of the paper 1 into contact with the paper feed roller 2 in a pressed state;
And a pressing spring 7 that is brought into contact with the pressing state.

[0003] Rotation fulcrum 5 on the left and right sides on the rear side of the pressing plate 3
Is supported by the side frame of the cassette case 14 so as to be tiltable. The papers 1 are provided on the left and right sides on the front side of the cassette case 14 and are separated so that the papers 1 fed out by the paper feed roller 2 are sent out one by one.
A separating claw 4 for positioning the front end of the sheet 1, a stopper 13 standing upright on the rear side to define a rear position of the sheet 1,
The position is determined.

When the paper feed roller 2 is rotated in the direction shown by the counterclockwise arrow in the drawing, the paper 1 is moved rightward in FIG. Only the one is fed out to the right in the direction of the arrow.

[0005]

As described above, according to the conventional automatic paper feeding mechanism, the pivot 5 at the rear side of the pressing plate 3 is supported only by the side frame of the cassette case 14 so as to be tiltable. , Its position is fixed.

For this reason, as shown in FIG. 2, since the maximum number of sheets 1 can be loaded on the pressing plate 3, the upper surface of the sheet 1 is maintained in a substantially horizontal posture in this state. The paper 1 fed out to a certain number of sheets is substantially in the horizontal direction.

However, as shown in FIG. 3, when the number of remaining sheets decreases, the pressing plate 3 becomes closer to the sheet feeding roller 2 so that the front of the pressing plate 3 becomes upward with the rotation fulcrum 5 as a center. Will be inclined.

In such a state, the sheet 1 is fed out obliquely upward in the direction of the arrow as shown in the figure, so that the sheet is not inserted into the sheet guide that is arranged continuously to the sheet feeding mechanism. There is a possibility that inconvenience may occur as a driving obstacle.

Conventionally, in order to reduce the above-mentioned inconvenience of the pressing plate 3, as shown in the drawing, the position of the rotation fulcrum 5 is inclined to the rear end of the sheet 1 as far as possible. Therefore, there is also a problem that the size of the cassette case 14 cannot be reduced because the number of the cases is reduced.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an automatic paper feed mechanism that stabilizes the paper feeding direction even when the number of papers stacked on a pressing plate is large. It is an object of the invention.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the gist of the present invention is to provide a paper feed roller which comes into contact with the upper surface of a sheet and sequentially feeds the sheets one by one from the upper side with rotation. The cassette case has a pressing plate that supports sheets of a predetermined size to be stacked and placed, and the cassette case is located forward of a position where the sheet is sent out from a contact position with the sheet feeding roller. And a pressing spring that pushes up the pressing plate on the side to bring the upper surface of the paper into contact with the paper feed roller in a pressed state, and is provided on both side frames at a rear side position where the paper is stacked relative to a contact position with the paper feed roller. An elongated hole extending in the stacking direction of the sheets, a pivot fulcrum provided in the pressing plate and engaged with the elongated hole to tilt the pressing plate and to be able to move up and down along the elongated hole; Plate pivot An arm extending downward from a side of the cassette case, a cam surface is provided on the outside of the cassette case so that a tip end of the arm contacts and raises and lowers the rear side of the pressing plate in accordance with the tilt of the arm. As the sheets stacked on the pressing plate are sequentially fed and fed by the feed roller, the number of stacked sheets decreases, and the front side of the pressing plate is pushed up by the pressing spring, and is tilted about the pivot point. As a result, the arm extending from the pressing plate is tilted about the pivot point, and the tip of the arm rises on the cam surface, and the pivot point becomes a slot in the side frame in accordance with the elevation of the arm tip. This is an automatic paper feed mechanism that is moved up along the rear side of the pressing plate while being moved up.

[0012]

According to the gist of the means of the present invention, a pressing spring is provided which pushes up a pressing plate on the front side where a sheet is sent out from a contact position with a sheet feeding roller and contacts the upper surface of the sheet with the sheet feeding roller. The pressing plate can be tilted and moved in the long hole by being engaged with the long hole extending in the sheet stacking direction provided in the side frame at the rear side position where the sheets are stacked relative to the contact position with the sheet feeding roller. By providing the rotation fulcrum and the cam surface with which the lower end on the rotation fulcrum side of the pressing plate contacts, for example, as the number of sheets decreases and the remaining number decreases, the front of the pressing plate is pushed up by the pressing spring. Comes closer to the paper feed roller.

[0013] This means that the pressing plate is pushed up by the pressing spring on the front side about the turning fulcrum on the rear side, but actually, the contact point on the upper surface of the sheet which is in contact with the sheet feeding roller is supported by the fulcrum. Will be tilted.

The pivot point on the rear side of the pressing plate is rotated in accordance with the tilting of the pressing plate, and the lower end thereof is also tilted forward, so that the tip moves and rises along the cam surface. I will be. This rise will cause the pivot point to move upward along the engaged long hole. As a result, the rear side of the pressing plate is lifted, so that the pressing plate, that is, the inclination of the sheet becomes gentle, and the leading edge of the sheet feeding is maintained in the horizontal direction as compared with the related art, so that no problem occurs.

[0015] Since such a thing is nothing other than actively utilizing the inclination posture of the pressing plate, the position where the rotation fulcrum of the pressing plate is greatly extended to the rear side is considered. Therefore, the size of the apparatus can be significantly reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The automatic paper feed mechanism of the present invention will be described in detail below with reference to the accompanying drawings, by way of an embodiment based on the gist of the configuration. It is to be noted that like parts are denoted by like reference numerals throughout the drawings.

FIG. 1 shows an embodiment of the present invention, which is shown in a schematic side sectional view of a main part. The automatic paper feed mechanism of the present invention contacts the upper surface of a sheet 1 such as a cut sheet of a predetermined size and rotates.
With this, the paper 1 is sequentially sent one by one from the upper side.
Cassette case 15 arranged below paper feed roller 2
To support the paper 1 of a predetermined size to be stacked and placed.
Paper 1 is sent out from the contact position between plate 8 and paper feed roller 2
The pressing plate 8 is pushed up on the front side on the right side of the drawing to
Spring for bringing the upper surface of the paper into contact with the paper feed roller 2 in a pressed state
7, the paper 1 is stacked more than the contact position with the paper feed roller 2.
Of the cassette case 15 at the rear position on the left side
Provided in the side frame 16 on the side in the stacking direction of the paper 1
The elongated hole 10 that extends is engaged with the elongated hole 10 provided in the pressing plate 8.
The pressing plate 8 is tilted and moved up and down along the slot 10.
Rotating fulcrum 9 that can move in the direction
Arm 12 extending downward from the side, and a distal end of arm 12
12a comes into contact with and after the pressing plate 8 in accordance with the tilt of the arm 12.
And a cam surface 11 whose one side is raised and lowered .

The paper 1 is provided on the front left and right sides of the cassette case 15, and is fed out by the paper feed roller 2.
Are separated so as to be sent out one by one, and are positioned by a separation claw 4 for positioning the front end of the sheet 1 and a stopper 13 standing upright on the rear side to define the rear position of the sheet 1. ing.

With the above configuration, when the paper feed roller 2 is rotated in the counterclockwise direction shown in the figure, the paper 1 is moved rightward in the figure, and is separated by the separation claw 4 so that the uppermost sheet is removed. Only the right is extended to the right.

The state shown by the solid line in the figure is a state in which the sheets 1 are almost fully loaded, and the sheet 1 to be sent is in the horizontal direction. As the number of sheets successively sent out and stacked on the pressing plate 8 decreases and the number of remaining sheets decreases, the front of the pressing plate 8 is pushed up by the extension of the pressing spring 7 as shown by a two-dot chain line, and the paper feed roller Come closer to 2.

This means that the pressing plate 8 is pushed up by the pressing spring 7 on the front side about the turning fulcrum 9 on the rear side. May be tilted with the contact point as a fulcrum.

The turning fulcrum 9 on the rear side of the pressing plate 8 is turned counterclockwise in response to the tilting of the pressing plate 8, and the tip 12a of the lower arm 12 is tilted in the same direction.
The tip portion 12a moves and rises along the inclined surface of the cam surface 11 sequentially.

In this upward movement, the turning fulcrum 9 moves upward along the engaged long hole 10 again. As a result, the rear side of the pressing plate 8 is lifted, the inclination of the pressing plate 8, that is, the sheet 1 becomes gentler, and the leading end of the feeding of the sheet 1 is maintained in the horizontal direction as compared with the related art, and the conventional problem is solved. Is done.

As described above, since the tilting posture of the pressing plate 8 is positively used, it is necessary to set the rotation fulcrum 9 of the pressing plate 8 to a position that largely extends rearward. This makes it possible to significantly reduce the size of the device.

By properly setting the inclination of the cam surface, the inclination of the stacked sheets 1 can be reduced, and the inclination of the leading edge of the fed sheet 1 can be reduced. Is eliminated, and stable paper feeding is performed.

The cam surface 11 is provided outside the cassette case 15 in an apparatus on which the cassette case 15 is placed.

Although the illustrated pressing plate 8 has a length up to the vicinity of the rotation fulcrum 9, the stopper 13 is located farther than the position of the rotation fulcrum 9.
By extending the rear side of the rotating plate 8 to the vicinity, stable support can be performed without hanging the rear side of the paper 1.

[0028]

As described above in detail, the automatic paper feeding mechanism of the present invention comes into contact with the upper surface of the paper and rotates the paper.
Below the paper feed roller to send out the paper one by one sequentially from the top
The cassette case placed in the
Between the pressure plate that supports the paper
The pressing plate on the front side where the paper is sent out from the touch position
And press the top of the paper
Above the contact position between the pressing spring and the feed roller.
Side frames on both sides at the rear side where the paper is stacked
A long hole provided in the paper stacking direction and provided on the pressing plate;
The press plate is tilted and engaged with the long hole provided in
A fulcrum that can move up and down along the long hole,
An arm extending downward from the rotation fulcrum side of the pressing plate;
The tip of the arm comes in contact with the arm and
With a cam surface on which the rear side of the pressing plate moves up and down.
As the number of sheets stacked on the plate decreases, the front side of the
It is pushed up by the pressure spring and tilts around the pivot point.
Arm extending from the pressing plate
It is tilted to the center, and the tip of the arm rises up the cam surface,
The rotation fulcrum is side-flagged as the arm tip rises.
Of the press plate
The side is moved up.

By such movement, the front side of the pressing plate is pushed up by the pressing spring about the pivot point, and is tilted about the contact point on the upper surface of the sheet which is in contact with the sheet feeding roller.

The rotation fulcrum of the pressing plate is also rotated, and moves upward along the cam surface as its lower tip is tilted forward, and the rotation fulcrum rises along the elongated hole.
Since the rear side of the pressing plate is lifted, a special action and effect are brought about such that the inclination of the sheet becomes gentle and the leading end of the fed sheet is maintained in a horizontal state.

Since it is not necessary to position the rotation fulcrum of the pressing plate on the rear side, it is possible to reduce the size of the apparatus.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an automatic sheet feeding mechanism of the present invention.

FIG. 2 is a side sectional view (part 1) of a conventional automatic sheet feeding mechanism.

FIG. 3 is a side sectional view (part 2) of a conventional automatic sheet feeding mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper 2 Paper feed roller 4 Separation claw 7 Press spring 8 Press plate 9 Rotating fulcrum 10 Slot 11 Cam surface 12 Arm 12a Tip part 13 Stopper 15 Cassette case 16 Side frame

Claims (1)

(57) [Claims] 1. A cassette case disposed below a paper feed roller that contacts the upper surface of a sheet and sequentially feeds the sheet one by one from the upper side as the sheet rotates , and the cassette case is stacked and mounted. A pressing plate for supporting a sheet of paper of a predetermined size, and pressing the pressing plate to push up the pressing plate on the front side where the sheet is sent out from a contact position with the sheet feeding roller so that the upper surface of the sheet is brought into contact with the sheet feeding roller in a pressed state. A spring, an elongated hole provided in both side frames at a rear side position where the paper is stacked relative to a contact position with the paper feed roller and extending in the stacking direction of the paper, and an elongated hole provided in the pressing plate. comprising a rotation fulcrum to allow vertical movement of the pressing plate along the tilt and the long hole engaged with an arm extending downward from the pivot point side of the pressing plate, the outer of said cassette case The above Contact
Touch and move the rear side of the pressing plate up and down according to the tilt of the arm.
A cam surface is provided, and the front side of the pressing plate is pushed up by a pressing spring due to a decrease in the number of stacked sheets due to the sheet stacked and mounted on the pressing plate being sequentially fed and fed by a feed roller. The arm extending from the pressing plate is tilted about the rotation fulcrum by being tilted about the moving fulcrum , and the tip of the arm rises on the cam surface and rotates in accordance with the rise of the arm tip. The fulcrum is moved up along the long hole of the side frame
With that, the automatic paper feeding mechanism, characterized in that the rear side of the pressing plate is moved up.