JPH0664765A - Paper feeder for picture forming device - Google Patents

Abstract

PURPOSE:To perform mounting/removing operation while preventing paper from being slid on a paper feed roller corresponding to mounting/ removing a paper feed cassette to/from the front side of a picture forming device main unit. CONSTITUTION:In a bottom plate 5 for supporting paper in the inside of a paper feed cassette 1, protruding parts 7, 8 are arranged in a side part and a front side, to provide a lever member 20 and a stopper member 25 corresponding to the protruding parts. The lever member 20 is slid on a guide surface provided in the upper surface of a guide member 30, and a rear side arm 23 performs action of pressing down the protruding part 7. The stopper member 25, which performs lock action against the protruding part 8, holds the protruding part 8 on the halfway or mounting/removing the paper feed cassette in a position where the bottom plate is pressed down by the lever member, and in the case of inserting the paper feed cassette, a stop condition is released by an end part of a groove provided in the guide member.

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 provided with a mechanism for urging a bottom plate supporting a sheet upward by using a spring and a separating mechanism with a separating claw, and more particularly to a sheet feeding cassette. A mechanism is provided to hold the paper in a depressed state when it is attached to or detached from the paper feed unit of the image forming apparatus, and bias the paper toward the paper feed roller when the paper feed cassette is inserted to a predetermined position. The present invention relates to a sheet feeding device of an image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine or a printer, a paper feeding unit is equipped with a plurality of paper feeding members such as a paper feeding tray and a paper feeding cassette to accommodate papers of different sizes. By doing so, it is possible to easily deal with changes in the size of the original and the reduction / enlargement ratio. Of the paper storage members, a paper feed tray is often used in which a bottom plate for supporting paper is provided so as to be movable up and down. The plate is raised and the paper is pressed against the paper feed roller to perform the paper feeding operation.

On the other hand, in the case of a paper feed cassette,
For example, Japanese Patent Laid-Open No. 55-105259 and Japanese Utility Model Publication No. 5
As shown in Japanese Patent Laid-Open No. 6-6832, a bottom plate that supports a sheet is swingably supported inside a sheet feeding cassette through a biasing member such as a spring. Then, when the paper feed cassette is mounted in the paper feed unit of the image forming apparatus, immediately, a state in which the paper is biased toward the paper feed roller is set, and the paper feed roller is driven to direct the paper to the image formation unit. It is designed so that it can be fed. Further, when using a paper urging mechanism in which a spring is not provided for the bottom plate, a mechanism for pushing up the bottom plate is arranged in the paper feeding section of the apparatus body, and when the paper feeding cassette is installed, The plate push-up mechanism operates to urge the paper toward the paper feed roller.

As described above, as the sheet accommodating member used in the image forming apparatus, various mechanisms such as a case where the sheet is attached to the sheet feeding section from the side of the apparatus body and a method of attaching from the front side of the apparatus body are used. However, generally, a paper feed tray is often used in a device in which the tray is attached and detached from the front side. Further, in a device in which a paper feeding unit is arranged on a side portion of the apparatus main body and a paper accommodating member can be mounted from the side, a paper feeding cassette is often used. From the paper feed cassette, the paper can be fed while being separated by the feeding operation by the paper feed roller and the separating claws arranged corresponding to the corner portions of the paper.

[0005]

As described above, even when the image forming apparatus is provided with a mechanism for feeding paper from the front side of the apparatus main body, it is considered to use a paper feed cassette instead of the paper feed tray. By configuring the paper feed mechanism using the paper feed cassette, it is possible to simplify the paper separation mechanism in the paper feed unit and reduce the manufacturing cost of the paper feed mechanism. However, in the conventional paper feed cassette, there is a problem that it is difficult to mount the cassette from the front of the apparatus because the paper is projected on the front upper surface of the cassette. Further, when the paper is still protruding upward, the paper comes into contact with the paper feed roller when the paper feed cassette is attached or detached, which damages the paper or adversely affects the paper feed roller. There's a problem.

Therefore, for example, as shown in Japanese Utility Model Laid-Open No. 56-6832, a lock mechanism is arranged for a bottom plate for supporting a sheet, and when the sheet cassette is attached or detached, It is conceivable to operate the lock mechanism to configure a mechanism in which the paper does not protrude upward. However, even if a mechanism for lowering the bottom plate with respect to the paper feed cassette is provided as shown in the conventional example, the paper feed cassette is moved up and down with respect to the bottom plate in correspondence with the operation of attaching and detaching the paper feed cassette from the front side of the apparatus. It is difficult to control motion. Then, a mechanism for locking the bottom plate as shown in the conventional example,
When applied to a device in which the paper feed cassette is mounted from the front side of the device, in addition to the complicated structure of the operating member for the bottom plate, each time the paper feed cassette is attached and detached,
There is a concern that the burden on the operator will increase, such as the need to operate the members provided in the paper feed cassette or the paper feed unit.

[0007]

SUMMARY OF THE INVENTION As described above, the present invention solves the problem of constructing a device for attaching and detaching a paper feed cassette from the front side of the main body of the device, and uses a mechanism for controlling the swing of the bottom plate. An object of the present invention is to provide an apparatus that can easily control the position of a sheet by linking the sheet cassette with the attachment / detachment operation by combining the sheet cassette with the guide member of the apparatus main body.

[0008]

In the paper feeding apparatus of the present invention, a bottom plate provided inside the paper feeding cassette so as to be swingable supports the paper, and the bottom plate is attached to the paper feeding roller. A biasing spring member is arranged, and separation pawls are arranged corresponding to the corners on both sides of the paper supported by the bottom plate. The separation pawl and the paper feed roller operate to separate and feed the paper. Regarding a paper making device. In the present invention, a side protrusion and a front protrusion are provided at predetermined positions corresponding to the front side of the paper feed side and the front side of the insertion side of the cassette with respect to the bottom plate that supports the paper inside the paper feed cassette. Are arranged so as to project respectively, and the lever member and the stopper member are swingably arranged so as to correspond to the side projections and the front projections, respectively. A guide member is disposed at a position on the front side of the paper feeding side, and guide surfaces of different heights are provided on the upper surface of the main body of the guide member. , A lever member that is swung along the guide surface on the upper surface of the guide member by the action of attaching and detaching the paper feed cassette to and from the paper feed unit,
A mechanism for controlling the swinging of the bottom plate is constituted by a stopper member that acts to push down the bottom plate and that is arranged corresponding to the guide groove of the guide member.

In the sheet feeding device of the image forming apparatus of the present invention, the lever member provided in the sheet feeding cassette is swingably supported by the side plate of the cassette via a horizontal shaft.
A front arm that protrudes forward of the cassette on the paper feed side and a rear arm that presses the front protrusion of the bottom plate are provided.
When sliding the front arm along the guide member,
The rear arm can exert the action of pushing down the bottom plate in response to the vertical movement by the guide surface of the guide member. Further, in the present invention, the stopper member arranged corresponding to the front projection of the bottom plate is swingably supported via the vertical shaft with respect to the front plate of the cassette and protrudes to the front side of the cassette. A front arm and a rear arm capable of projecting toward the inside of the cassette are provided, and the front arm is projected forward,
Providing a means for urging the rear arm with respect to the front protrusion,
With the bottom plate pushed down by the lever member,
The bottom plate is pushed down by the stopper member and is engaged with the rear wall of the guide groove of the guide member.
A mechanism for releasing the locked state of the bottom plate can be provided.

As described above, according to the present invention, the bottom plate of the paper feed cassette is held at the lowered position and the paper feed cassette is attached to the paper feed section when the paper feed cassette is attached or detached. Thus, the sheet supported by the bottom plate can be raised to a position corresponding to the sheet feeding roller.
Then, a mechanism for attaching and detaching the paper feed cassette can be configured with respect to the main body of the image forming apparatus. Also, when mounting the paper feed cassette, the operator only needs to perform the operation of mounting the paper feed cassette, and the bottom plate is automatically raised at the paper feed position to bias the paper to the paper feed roller. it can. Furthermore, even when replenishing paper in the paper feed cassette, you can cancel the state where the paper is in contact with the paper feed roller by simply pulling out the paper feed cassette.
It is possible to prevent the feed roller from being damaged.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet feeding device of an image forming apparatus according to the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 shows the configuration of the sheet feeding cassette 1 of the present invention and a guide member 30 arranged in the sheet feeding portion of the image forming apparatus. In FIG. Only the front part of the paper part and a part of the rear side are shown. In the paper feeding portion of the apparatus main body, as a mechanism for attaching and detaching the paper feeding cassette 1, a guide member and a guide member 30 as an operating member for the lever member 20 and the stopper member 25 provided in the paper feeding cassette are arranged. is doing. In the paper feed cassette 1, in addition to the side plate 2 forming the frame and the front plate 3 on the paper feed side, vertical plate members forming peripheral members are arranged to partition the periphery of the portion for storing the paper. ing.

In the paper feed cassette 1 shown in FIG.
As in the case of the conventional general cassette, a mechanism for urging the sheet toward the sheet feeding roller 15 (shown in FIG. 3) is provided by the spring 9 arranged under the bottom plate 5 supporting the sheet. There is. Further, with respect to the sheet supported by the bottom plate 5, the separating claws 10 are arranged corresponding to the corners on the front side of the sheet feeding side to configure a separating means for the sheet to be fed. The bottom plate 5
The front protrusion 8 is disposed on the front side of the sheet feeding side, and the side protrusion 7 is disposed on the side of the bottom plate.

Further, the paper feeding cassette 1 is provided with a lever member 20 for pushing down the bottom plate corresponding to the side projection 7 provided on the bottom plate 5, and the lever member 20 supports the fulcrum 21. Is attached to the side plate 2, and the front arm 22 and the rear arm 23 are provided in a bent state at a predetermined angle. A spring 24 is arranged on the rear arm 23 of the lever member, and the rear arm 2
3 is rocked upward and the front arm 22 is biased downward. Further, the front arm 22 of the lever member is provided so as to project to the front side of the front plate 3 of the paper feed cassette, and when the paper feed cassette is attached and detached in the X direction, the front arm 22 serves as a guide member 30. By sliding on the upper surface of the main body 31, the guide surface 32 of the guide member
It is designed to be swung along 34.

A stopper member 25 is arranged on the front plate 3 of the paper feed cassette 1 so as to correspond to the front projection 8 provided on the bottom plate 5. As shown in FIG. The member 25 is swingably provided inside the opening 4 provided in the front plate 3 via a vertical shaft 26. Further, a spring 27 is arranged with respect to the stopper member 25, and the spring 27 biases the stopper member 25 in a counterclockwise direction as shown by a virtual line in the figure. The stopper member 25 is composed of a linear plate member, and is provided with a front arm 28 and a rear arm 29 with a vertical axis 26 as a boundary. The front arm 28 is arranged at a position projecting to the front side of the sheet feeding cassette, and the rear arm 29 is arranged so as to project toward the inside of the sheet feeding cassette. The rear arm 29 of the stopper member 25 locks and holds the front projection 8 of the bottom plate 5 at a position to lower the bottom plate, and the front arm 28 guides the guide member 30. Groove 35 (shown in FIG. 5)
The paper feed cassette 1 is mounted in the paper feed unit under the condition that the paper feed cassette 1 is guided.

In the sheet feeding cassette 1 of the present invention configured as described above, as shown in FIG. 3, even when the bottom plate 5 is raised, the upper surface of the bottom plate on which no sheet is placed is It is held at a position where it does not contact the half-moon-shaped feed roller 15. As the means, for example, fulcrum 1
A means for restricting the range of rotation of the claw supporting arm 11 which is swung via 2 is provided, and the bottom plate 5 is held at the position controlled by the separation claw 10 even at the most protruding position. The state Therefore, in this state, the bottom plate does not slide with respect to the paper feed roller 15 even if the paper feed cassette is attached to or detached from the paper feed unit.

In addition, when replenishing the paper to the paper feed cassette, as shown in FIG.
At the lowered position, the sheet is placed on the bottom plate while being locked by the stopper member 25. Note that setting the lowered position of the bottom plate 5 allows the operator to push down the bottom plate, rotate the stopper member 25, and lock the rear arm 29 to the front protrusion 8. However, the front arm 22 of the lever member 20 slides on the central guide surface 33 of the guide member 30 when the paper cassette is attached or detached, so that the lever member is rotated counterclockwise in the drawing. To move
The bottom plate can also be pressed by the rear arm 23.

The guide member 30 arranged at a position corresponding to the front arm 22 of the lever member 20 is formed in a shape as shown in FIG. In the example shown in FIG. 5, three guide surfaces 32, 33, 34 having different heights are formed on the upper surface of the main body 31 of the guide member 30, and the central guide surface 33 is projected the highest. The front guide surface 32 is formed to be the lowest. When the paper feed cassette is inserted toward the paper feed unit, the front arm of the lever member 20 slides along the guide surface,
When the front arm 22 slides on the central guide surface 33, the rear arm 23 lowers the bottom plate 5 to the lowest position, as shown in FIG.

Therefore, as shown in FIG.
When the bottom plate 5 is pushed down, the stopper member 2
As shown in FIG. 2, 5 is rotated counterclockwise with respect to the shaft by the force of the spring, and the rear arm 29 is projected to a position corresponding to the front projection 8. Then, the bottom plate 5 is fixed and held at the depressed position, and
Until the paper feed cassette is inserted into the paper feed unit to a predetermined depth, the upper surface of the paper placed on the bottom plate is held at a position where it does not contact the paper feed roller.

Further, a guide groove 35 is arranged on the side of the guide member 30 on the side of the sheet feeding cassette so as to guide the front arm 28 of the stopper member 25 provided on the sheet feeding cassette. The guide groove 35 has an opening at the end (front side) on the insertion side of the paper feed cassette, and a rear wall 36 is provided just before the rear end of the central guide surface 33.
Then, when the front projection of the bottom plate is locked by the stopper member, the locked state of the bottom plate by the stopper member is released when the paper feed cassette is inserted. After that, when the front guide surface is moved to a position corresponding to the rear guide surface 34 to release the pressing state of the side projection of the bottom plate, the paper placed on the bottom plate is fed by the paper feed roller. Is in contact with
With the paper feed cassette inserted into the back of the paper feed unit, each member is set to the position shown in FIG. 1 and the paper feed roller is driven so that the paper can be fed out.

As described above, when pulling out the paper feed cassette set in the paper feed section, from the position shown in FIG.
The operation of each member is started. That is, in the process of pulling out the paper feed cassette 1, the lever member 20 is swung from the state where the bottom plate is not pressed as shown in FIG. 3 to the state shown in FIG. , Lower the paper to a position where it does not contact the paper feed roller. Then, when the bottom plate is pushed down, the front arm of the stopper member passes the position of the rear wall of the guide groove, and the regulation by the side wall of the main body of the guide member is released, the force of the spring causes the front arm to move to the guide groove. Rotate to the state of protruding. After that, when the paper feed cassette is still pulled out, the front guide surface slides from the position where it slides on the central guide surface to the front guide surface 32, and the action of pushing down the side projection is released. However, at this time, since the stopper member locks the front projection, the bottom plate 5 is held in the lowered position, and the paper feed cassette is pulled out without the paper protruding above the paper feed cassette. be able to.

As described above, in the paper feeding cassette of the present invention, when the bottom plate is pushed down and fixed by the stopper member, when the cassette is attached to the paper feeding portion, the cassette is placed at the predetermined position. While the sheet is being inserted, the sheet is prevented from protruding to the position where it contacts the sheet feeding roller. Even when the cassette is pulled out, the bottom plate is automatically lowered by the front guide surface and held at the fixed position by the stopper member while the cassette is being pulled out, so that the paper does not come into contact with the paper feed roller. Moved in a state. In the paper feeding device of the present invention, the paper is raised at the position where the paper feeding cassette is being inserted, but since the position of the upper surface of the paper is regulated by the separating claw, the paper is not fed to the paper feeding roller. I have no contact. That is, as shown in FIG. 3, since the rising position of the separating claw 10 is restricted, not only the rising position of the bottom plate but also the rising position of the sheet can be restricted by the separating claw.

[0022]

As described above, in the sheet feeding device of the image forming apparatus of the present invention, two lever members are arranged with respect to the bottom plate of the sheet feeding cassette, and the lever is provided by the guide member provided in the sheet feeding portion. Since the mechanism that swings the member is used, when the paper cassette is mounted, the operator only has to perform the operation of mounting the paper cassette, and the bottom plate is automatically raised at the paper feeding position to feed the paper. It can be biased against the paper roller. Further, in the present invention, when the operation of attaching / detaching the paper feed cassette is performed, the bottom plate of the paper feed cassette is held in the lowered position, and the paper feed cassette is mounted on the paper feed unit and then supported by the bottom plate. The sheet to be formed can be raised to a position corresponding to the sheet feeding roller. Then, a mechanism for attaching and detaching the paper feed cassette can be configured with respect to the main body of the image forming apparatus. Furthermore, even when replenishing the paper in the paper feed cassette, the state in which the paper comes into contact with the paper feed roller can be released by simply pulling out the paper feed cassette, so that the paper feed roller can be prevented from being damaged. .

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a paper feed cassette of the present invention.

FIG. 2 is an explanatory diagram of a stopper member provided on the front plate of the paper feed cassette.

FIG. 3 is a side view showing a state in which a bottom plate is held in a raised position.

FIG. 4 is a side view showing a state in which a bottom plate is held in a lowered position.

FIG. 5 is a perspective view of a guide member.

[Explanation of symbols]

1 paper feed cassette, 2 side plates, 3 front plate, 5
Bottom plate, 7 side protrusions, 8 front protrusions, 9 springs, 10 separation claws, 1
5 paper feed roller, 20 lever member, 22 front arm, 23 rear arm, 24 spring, 25 stopper member, 28 front arm,
29 rear arm, 30 guide member, 32.3
3.34 guide surface, 35 guide groove.

Claims (3)

[Claims] 1. A paper feed cassette is provided with a bottom plate swingably provided therein to support a paper, and a spring member for urging the bottom plate toward a paper feed roller is arranged and is supported by the bottom plate. In a device in which separating claws are arranged corresponding to the corners on both sides of the sheet to be fed and the action of the separating claw and the sheet feeding roller separates and feeds the sheet, the sheet is fed inside the sheet feeding cassette. With respect to the bottom plate to be supported, the side protrusions and the front protrusions are arranged so as to protrude at predetermined positions corresponding to the front side of the sheet feeding side and the front side of the insertion side of the cassette. The lever member and the stopper member are swingably arranged in correspondence with the front protrusion, and the guide member is arranged at a position in front of the paper feeding side with respect to the paper feeding cassette mounting portion of the image forming apparatus. , Guide surfaces with different heights are provided on the upper surface of the main body of the guide member, and a guide groove is provided on the side of the main body of the guide member on the slide side of the paper feed cassette to attach and detach the paper feed cassette to the paper feed section. By the action, the bottom member is pushed down by the lever member which is swung along the guide surface on the upper surface of the guide member, and the stopper member arranged corresponding to the guide groove of the guide member causes the bottom plate to move. A sheet feeding device of an image forming apparatus, which is characterized by controlling swing. 2. A lever member provided in the paper feeding cassette is swingably supported by a side plate of the cassette via a horizontal spindle, and a front arm protruding forward of the cassette on the paper feeding side and a front of the bottom plate. A rear arm that presses the protruding portion, and when sliding the front arm along the guide member,
The sheet feeding device of the image forming apparatus according to claim 1, wherein the rear arm exerts an action of pushing down the bottom plate in response to the vertical movement by the guide surface of the guide member. 3. A front arm, which is disposed so as to correspond to a front projection of the bottom plate, is swingably supported on a front plate of the cassette via a vertical shaft, and protrudes to the front side of the cassette. And a rear arm capable of projecting toward the inside of the cassette, and means for projecting the front arm to the front side to urge the rear arm against the front protrusion, and a bottom member by a lever member. A mechanism is provided that locks the bottom plate with the stopper member while pushing down the plate and releases the locked state of the bottom plate at the position where it engages with the rear wall of the guide groove of the guide member. The sheet feeding device of the image forming apparatus according to claim 1 or 2.