JP2886537B2 - Paper feeder - Google Patents

Description

The present invention relates to an image forming apparatus, for example, a copying machine, a printer,
The present invention relates to a sheet feeding device such as a facsimile.

(Prior art)

Conventionally, in a copying machine, a method of replenishing sheets with a cassette has been used, and in order to detect the presence or absence of the cassette, the paper end lever is set or released in conjunction with the movement of a bottom plate pressing plate of the cassette. It is configured.

In such a conventional apparatus, when a cassette is attached and detached to supply paper in a direction orthogonal to a paper feeding direction,
There is a problem in that the paper end detecting lever interferes with the edge of the cassette, the side fence, or the bottom plate when the cassette is attached or detached, and is easily damaged.

Further, the conventional apparatus as described above cannot be used for a simple sheet feeding mechanism without a bottom plate pressing plate, and the use of the bottom plate pressing plate increases the cost and requires a lot of space.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a paper feeding device capable of preventing breakage without interfering with a paper end detection lever.

[Means for solving the problem]

The present invention has the above object with a sheet storage member that is detachably attached to an image forming apparatus main body by either linear movement in a direction substantially perpendicular to a sheet feeding direction or turning movement from a horizontal position. In the paper feeding device, a paper end lever rotatable between a set position on the paper in the paper storage member and a retracted position away from the paper, and a sensor is operated in conjunction with the paper end lever. A paper detection lever for operating a lever that is provided integrally with the paper end lever and the paper detection lever, and that can rotate together with the paper end lever and the paper detection lever in a plane orthogonal to the mounting direction of the paper storage member. Between the position where the paper end lever is held at the retracted position via the operating lever and the position away from the operating lever. An intermediate lever for rotatably mounting direction parallel to the plane of the paid member, relative to the intermediate lever, always
A spring for applying a force in the direction of moving to the holding position, and a spring provided at the end of the paper storage member in the mounting direction and within a paper width orthogonal to the mounting direction of the paper storage member, and the paper storage member is set at a predetermined position. In this case, there is provided a sheet feeder having a return member for rotating the intermediate lever from the holding position to a position away from the holding position against the force of the spring.

[Action]

According to the present invention, when the sheet storage member, for example, the cassette is not mounted in the image forming apparatus, the paper end lever is held at the retracted position via the operation member by the action of the spring. Therefore, the cassette can be freely mounted and does not hit the paper end lever.

At the time of mounting, the set member provided on the cassette moves the operating member at a predetermined position, and when the cassette is mounted at the predetermined position, the paper end lever moves to the set position where it comes in contact with the paper in the cassette.

According to the present invention, it is possible to avoid interference with the paper detection lever in the paper end lever even when the cassette is attached or detached.

〔Example〕

 The details of the present invention will be described based on an embodiment shown in the drawings.

In FIG. 1, an electrostatic latent image is formed on a photosensitive drum 1 of a copying machine as an example of an image forming apparatus, and a visible image developed with a developer is transferred to a sheet. The paper is supplied from a paper storage member 3 mounted below the machine frame bottom plate 2 of the image forming apparatus, for example, a cassette.

The cassette 3 can be freely moved in and out of the front and back along the guide 4 formed by the machine frame bottom plate 2 from the front to the back of the drawing.

A bottom plate 5 for loading paper is supported in the cassette 3 by a fulcrum 6 so as to be rotatable up and down. The bottom plate 5 is pressed by a spring 7 stretched between the bottom 3a of the cassette 3 and the end near the outlet side of the paper. Has received the power to raise. Conner claws 8 are provided at both ends at the end of the cassette 3 on the exit side to prevent double feeding of sheets. The conner claw 8 is supported by a fulcrum 10 provided on a pair of side fences 9 of the cassette 3 so as to be vertically rotatable, and the upper limit of the movement is determined by the regulating means.

Both corners of the paper placed on the bottom plate 5 in the cassette 3 are pressed by the conner claws 8. In this state, the paper is fed in a direction orthogonal to the direction in which the cassette 3 is put in and taken out by the sheet feeding roller 11 arranged near the exit side end of the cassette 3.

As shown by the solid line in FIG. 1, the paper feed roller 11 is formed in a state where a part of the circumference is cut off, and feeds one sheet of paper every one intermittent rotation by a one-rotation clutch or the like.

The fed paper is disengaged from the corner claws 8 and is sent to the photosensitive drum 1 via the turn guide 12, the feed roller pair 13, and the registration roller pair 14.

A paper end shaft 15 is rotatably supported on the lower surface of the machine frame bottom plate 2. As shown in FIGS. 2 to 4, a paper end lever 16 is fixed to the paper end shaft 15 at a position convenient for contacting the paper in the cassette 3, for example, near the center of the cassette 3. A sensor detection lever 17 and an operation lever 18 as an operation member are fixed to a free end of the paper end shaft 15 extending outside the frame of the cassette 3. The center detection lever 17 and the operation lever 18 may be formed as a two-arm lever as an integral member, and may be called an actuator 19 and fixed to the paper end shaft 15.

The operating lever 18 abuts on a tip 21a of a lever 21 serving as an intermediate lever rotatably supported on a lever shaft 20 provided outside the cassette 3 of the machine frame, and is pushed by the lever 21 to move the paper. End lever 16 second
It moves to the retreat position shown by the solid line in FIG. 4 and FIG. In addition,
The lever 21 is rotatable about a lever shaft 20 between a holding position indicated by a solid line in FIG. 3 and a position away from the operating lever 18 indicated by a chain line.

A spring 22 is mounted on the lever 21, and the lever 21 is actuated by an operating member.
The force to move 18 to the retracted position is urged. The paper end lever 16 is held at the retracted position by the force of the spring 22 unless an external force is particularly applied to the lever 21.

The lever 21 is formed as a bell crank, one lever end is formed as a portion that abuts on the operating lever 18, and the other lever end is formed as a contact lever end 21b.

A projection 23 as a return member is provided on a rear surface of the cassette 3, that is, a surface that becomes a front end portion when the cassette 3 is inserted into the machine frame.

When the cassette 3 is mounted in the C direction, when the cassette comes to a position immediately before the mounting position, the projection 23 comes into contact with the contact lever end 21b,
The lever 21 is returned counterclockwise in the drawing and rotated against the force of the spring 22. The return rotation of the lever 21 moves the lever end 21a away from the operating lever 18. When the lever end 21a separates, the paper end shaft 15 rotates in the direction D due to the weight of the operation lever 18 and the paper end lever 16, and the paper end lever 16 comes into contact with the paper on the cassette 3 and is set.

When the paper end lever 16 rotates to the set position, the sensor detection lever 17 activates the sensor 24. sensor
The switch 24 is turned on by, for example, being formed as a photo interrupter and blocking light by the sensor detection lever 17. At this time, the paper end lever 16 is
Move from position A to position B in the figure. This indicates that there is no paper at this position.

When the seat plate 5 is pushed up and the paper end lever 16 is pushed up in contact with the sheet and rises above a predetermined position, the sensor detecting lever 17 turns off the sensor 24 to indicate that the sheet is present. The ON and OFF of the sensor 24 can be set in reverse. When the paper runs out, the paper end lever 16 goes down through the hole in the bottom plate 5 to the position B, and the sensor 24 indicates that there is no paper.

When the cassette 3 is taken out of the machine, the cassette 3 is moved to the front, and when the cassette 3 is moved a little, the projection 23 retreats.
The lever 21 rotates backward by the force of the spring 22, and the lever end 21a
Rotates the operating lever 18 in the direction E and pushes it up to move the paper end lever 16 to the retracted position. The return rotation position of the lever 21 by the force of the spring 22 is determined by the stopper 26.

When the cassette 3 is attached or detached, the sheet supply roller 11 does not hinder the attachment / detachment of the cassette because the circumferentially missing portion is located on the lower surface as shown in the figure.

When there is no cassette, the paper end lever 16 is moved to a standby position where it does not interfere with the cassette, and when the cassette is mounted, the cassette reaches a predetermined position so that the paper end lever 16 can be returned to the set position. Therefore, even when the cassette is quickly attached and detached, it is possible to prevent the components constituting the cassette 3 from interfering with or colliding with the paper end lever 16 or the like, thereby preventing the paper end lever or the cassette from being damaged by the shock.

It is preferable to consider the positional relationship so that the paper end lever can move to the retracted position when the cassette is slightly away from the set position. For this purpose, it is convenient to provide the projection 23 as a return operating member at the back in the pull-out direction. It is convenient for the projection 23 to protrude from a hole 25 provided in the side plate of the machine frame so as to abut on the contact lever end 21b. The contact lever end 21b may be formed so as to protrude from the hole 24 toward the cassette. In order to move the paper end lever 16 by a desired angle by a slight movement of the contact lever end 21b, the other lever end 21a of the lever 21 must be longer than the contact lever end 21b from the rotation center. It is good to constitute. It is to be noted that a link mechanism for expanding the movement can be formed as needed.

Conveniently, the paper end lever 16 is normally in contact with the paper with a force that does not hinder the feeding of the paper. However, since the paper end lever 16 after mounting the cassette is a mechanism for returning to the set position by its own weight, a good effect can be obtained. If necessary, a pressing force can be applied by a spring force within an allowable force range.

The projection as a return member at the time of attaching / detaching the cassette does not directly contact the operating member, and the shock can be relaxed and transmitted by the return spring by using the bell crank as the intermediate lever. It is also possible to omit the bell crank and directly contact the return member with the operating member.

In the example shown in the figure, the cassette is attached and detached in the direction perpendicular to the paper feeding direction. In this case, the present invention can be used.

Although an example of a cassette is shown as a sheet storage member, the present invention can be applied to a tray-type sheet feeding device or a duplex device. Further, the tray accommodating the cassette may be moved integrally.

〔effect〕

According to the present invention, when the cassette is not mounted, the paper end lever is moved and held at the upper standby position, so that even if the cassette is rapidly inserted, there is no possibility of damage to each part.

According to the present invention, the paper end lever can wait upward by slightly moving the cassette, so that even if the cassette is quickly pulled out, it is possible to avoid damage to each part. This effect was further enhanced by the return spring.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a cassette unit according to the present invention, FIG. 2 is a front view of a main part, FIG. 3 is a plan view, and FIG. 4 is a perspective view of a part related to a paper end lever. 1 photosensitive drum, 3 cassette 5 bottom plate 7 spring 11 paper feed roller 14 paper end shaft 16 paper end lever 17 sensor detection lever 18 operating lever (Operation member) 21 Intermediate lever (Operation member) 22 Spring, 23 Projection (Return member)

Claims (1)

(57) [Claims] 1. A sheet feeding device having a sheet storage member detachable from a main body of an image forming apparatus by a linear movement in a direction substantially perpendicular to a sheet feeding direction or a turning movement from a horizontal position. A paper end lever rotatable between a set position on the paper in the paper storage member and a retract position away from the paper, and a paper detection for operating a sensor in conjunction with the paper end lever A lever, an operation lever provided integrally with the paper end lever and the paper detection lever, and rotatable together with the paper end lever and the paper detection lever in a plane orthogonal to the mounting direction of the paper storage member; Between the position at which the paper end lever is held at the retracted position and the position away from the operating lever via the An intermediate lever that is rotatable in a plane parallel to the loading direction, a spring that constantly applies a force to the intermediate lever in a direction to move to the holding position, A return member that is provided within a sheet width orthogonal to the mounting direction of the member and that rotates the intermediate lever from the holding position to a position away from the holding position when the sheet storage member is set at a predetermined position; A sheet feeding device comprising: