JP2001139159A - Sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeder enhancing the workability of an operator in supplementing recording sheets. SOLUTION: This sheet feeder is characterized to have a cassette arranging sheets in a stacked state, a sheet feed roller feeding the stacked sheets by rotation, a presser plate for mounting the sheets swingably provided between the uppermost position abutting on the sheet feeding roller and the lowermost position separating from the sheet feeding roller along the vertical direction, a presser plate operation member displaced between an operation position forcedly swinging the presser plate to the lowermost position and non-operation position, a stopper provided in such a state as swingably suspended by a pivot positioned in the upper side than the uppermost position of the presser plate, swinging to a lock position, when the presser plate operation member swings the presser plate to the lowermost position, and regulating the swing in the direction of approaching the presser plate to the sheet feed roller, and a stopper operation member releasing the stopper from the lock position before the sheet feed roller implements an action feeding the sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for feeding sheets stacked in a sheet feeding cassette by a sheet feeding roller.

[0002]

2. Description of the Related Art In an image forming apparatus such as a printer or a copying machine, a paper feeder is provided in which a large number of recording papers (sheets) are prepared by laminating, and the recording papers are sequentially fed out and conveyed to an image recording section. Have been.

This paper feeder generally includes a cassette on which recording papers are stacked and arranged, and a paper feeder which is provided above the cassette and feeds the stacked recording papers from the uppermost layer every one rotation. The cassette is provided so as to be vertically swingable between a roller and an upper end position where the upstream end of the sheet feeding direction is pivotally supported by the cassette and abuts on the sheet feeding roller and a lower limit position where the roller is separated from the sheet feeding roller. A pressing plate on which the stacked recording papers are placed, and an elasticity for applying a force to swing the pressing plate upward to approach the paper feed roller to press the recording paper placed on the pressing plate into contact with the paper rollers. The pressing plate on which the recording papers are stacked is pushed up by an elastic member to press the recording papers against the paper feed roller. It is designed to be extended.

In this paper feeder, in order to swing the pressing plate from the upper limit position to the lower limit position against the force of the elastic member,
There are a method in which the user pushes down the pressing plate by hand and a method using a pressing plate operating member.

In the latter method, a pressing plate operating member is provided which is displaced between an operating position for forcibly swinging the pressing plate to a lower limit position and a non-operating position away from the lower limit position of the pressing plate. In other words, when the recording paper placed in the paper feed cassette runs out and it becomes necessary to replenish the recording paper, the user operates the pressing plate operating member to displace the operating plate to the operating position and move the pressing plate from the paper feeding roller. In a separated state, the recording paper is stacked and placed on the pressing plate, and then the pressing plate operating member is moved to the non-operation position, and the pressing plate is swung upward again by the elastic force of the elastic member to perform recording. The paper is pressed against the paper feed roller.

[0006]

However, the paper feeder employing the above-described system using the pressing plate operating member has the following problems. First, the first problem is as follows. When refilling the recording paper into the paper feed cassette, swing the pressing plate to the lower limit position, hold the pressing plate at that position so that the pressing plate does not return to the upper limit position until the replenishment of the recording paper is completed. After the replenishment is completed, it is necessary to swing the pressing plate toward the paper feed roller. In this case, when the user operates the pressing plate by hand, the user must press the pressing plate by hand and hold it at the lower limit position.

Further, there is a pressing plate operation member which is naturally returned from an operation position to a non-operation position.
This is because, for example, the elastic member applies a force in the returning direction, the pressing plate operating member generates a moving force in the returning direction by itself, or the pressing plate (recording paper placed on the pressing plate).
And a configuration in which a shape, a support position, and the like are set so as to be moved in the return direction by being pushed by the user. However, in this case, while the press plate operating member is moved to the operation position and the press plate is moved to the lower limit position, while replenishing the recording paper,
The user needs to hold the pressing plate operating member in the operating position so as not to return to the non-operating position against the force of an elastic member or the like that pushes up the pressing plate.

Accordingly, when replenishing the recording paper, the user is required to always press the pressing plate and the pressing plate operating member in addition to the operation of handling the recording paper, so that the workability is very poor.

The second problem is as follows. Some of the pressing plate operating members are configured such that conditions such as the pivot point position and the center of gravity position are set, and the pressing plate operation member stops by itself while being pressed at the operating position. In the case of using a pressing plate operating member of this type, it is necessary for the user to manually forcibly return the pressing plate operating member to the non-operation position after the replenishment of the recording paper is completed. Workability is very poor.

If the user forgets to return the pressing plate operating member to the original non-operating position after the replenishment of the recording paper, the pressing plate on which the recording paper is placed is separated from the paper feed roller. The recording paper placed on the pressing plate is not pressed against the paper feed roller while stopped at the lower limit position. Then, even if the recording paper is replenished in the paper feeding device, the paper is not fed and an error occurs in image recording.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper feeder which does not require an operator to manually push a pressing plate operating member to an operation position when replenishing recording paper, thereby improving workability.

It is an object of the present invention to provide a paper feeder in which it is not necessary for an operator to move a pressing plate operating member from an operating position where the pressing plate operating member presses the pressing plate to a non-operating position after replenishing recording paper, thereby improving workability. Aim.

[0013]

According to a first aspect of the present invention, there is provided a paper feeder comprising: a cassette on which sheets are stacked and arranged; and a sheet provided above the cassette and rotated to feed the stacked sheets from the uppermost layer. The paper feed roller and a paper feed direction upstream end are pivotally supported by the cassette and freely swing in the vertical direction between an upper limit position where the upper end position abuts on the paper feed roller and a lower limit position where the paper feed roller is separated therefrom. A pressing plate provided on the cassette for placing the paper stacked thereon, and applying a force in a direction in which the pressing plate approaches the paper feeding roller to feed the paper placed on the pressing plate to the paper feeding roller. An elastic member for pressing and contacting the pressing plate; a pressing plate operating member for displacing between an operating position for forcibly swinging the pressing plate to a lower limit position and a non-operating position away from the lower limit position of the pressing plate; Above the upper limit of the plate When the pressing plate operating member swings down the pressing plate to the lower limit position, it is slid downwardly by the pivot to be placed, and is provided with a downward swinging power by its own weight. A stopper that contacts the plate from above and restricts the pressing plate from swinging in a direction to approach the paper feed roller against the force of the elastic member and swings upward to separate from the pressing plate. It is characterized by having.

According to the configuration of the present invention, when the pressing plate operating member swings the pressing plate to the lower limit position, the stopper swings downward by its own weight and abuts against the pressing plate from above to elastically press the pressing plate. Since the swinging movement in the direction approaching the paper feed roller is restricted against the force of the member, it is not necessary for the operator to manually press the pressing plate and the pressing plate operating member to the operation position when replenishing the paper. Workability can be improved.

According to a second aspect of the present invention, in the paper feeder according to the first aspect, the stopper is located closer to an upstream end in the sheet feeding direction with respect to a vertical line passing through the pivot axis for supporting the stopper. The abutment at a position along a direction perpendicular to the plate surface of the pressing plate restricts the movement of the pressing plate, and the upward swing of the pressing plate toward the upstream end in the sheet feeding direction is performed. It is characterized by being possible.

According to a third aspect of the present invention, in the paper feeder according to the first aspect, the stopper is located at a downstream end in a sheet feeding direction with respect to a vertical line passing through the pivot for supporting the stopper. The abutment at a position along a direction perpendicular to the plate surface of the pressing plate restricts the movement of the pressing plate, and the upward swinging of the pressing plate toward the downstream end in the sheet feeding direction is performed. It is characterized by being possible.

According to a fourth aspect of the present invention, in the paper feeder according to the first aspect, the stopper is provided in a direction perpendicular to the plate surface of the pressing plate on a vertical line passing through the pivot for supporting the stopper. It is characterized in that the pressing plate is moved at a position along the same to restrict the movement of the pressing plate.

According to the second to fourth aspects of the present invention, it is possible to provide a specific structure capable of sufficiently exerting the function of the stopper.

According to a fifth aspect of the present invention, in the paper feeder according to the first aspect, the pressing plate operating member is partially disposed in the operating position for forcibly swinging the pressing plate to a lower limit position. It is characterized by protruding outside the paper feed cassette.

According to the present invention, it can be seen from the part of the pressing plate operating member protruding outside the cassette that the pressing plate is separated from the paper feed roller and paper is not being supplied. it can.

According to a sixth aspect of the present invention, there is provided a sheet feeder for stacking sheets of paper, and a sheet feeder provided above the cassette and feeding the stacked sheets of paper from the uppermost layer every one rotation. A roller and a paper feeding direction upstream end portion are pivotally supported by the cassette so as to freely swing along an up-down direction between an upper limit position where the upper end position abuts on the sheet feeding roller and a lower limit position where the end portion is separated from the sheet feeding roller. A pressing plate for placing the papers stacked and arranged on the cassette, and applying a force to the pressing plate in a direction approaching the paper feed roller to apply the paper placed on the press plate to the paper feed roller. An elastic member to be brought into pressure contact, a pressing plate operating member for displacing between an operating position for forcibly swinging the pressing plate to a lower limit position and a non-operating position away from the lower limit position of the pressing plate, and the pressing plate The operating member lowers the pressure plate A stopper that operates when swung to the position and restricts the swinging of the pressing plate in a direction to approach the sheet feeding roller against the force of the elastic member, and the sheet feeding roller rotates once to stack And a stopper operating member that removes the stopper from a position that restricts swinging of the pressing plate in a direction to approach the paper feed roller before performing an operation of feeding out the uppermost layer of the placed paper. I do.

According to the structure of the present invention, the number of the paper feed rollers is one.
Before performing the operation of rotating and feeding the top layer of the stacked paper, the stopper operation member removes the stopper from the position that regulates the swing of the pressing plate in the direction to approach the paper feed roller, so that the paper is replenished. After this, it is not necessary for the operator to move the pressing plate operating member from the operating position where the pressing plate is manually pressed to the non-operating position, and the workability can be improved.

According to a seventh aspect of the present invention, in the paper feeder according to the sixth aspect, the stopper operation member rotates in conjunction with the rotation of the paper supply roller to restrict the stopper from swinging the pressing plate. It is characterized in that it is a cam that is removed from the position where it does. According to the configuration of the present invention, it is possible to provide a specific configuration in which the stopper operation member can sufficiently exhibit its function.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. The paper feeder in this embodiment is mounted on an image forming apparatus and sequentially supplies recording paper to an image recording unit. FIG. 1 is a side view showing an image forming apparatus, FIG. 2 is a plan view schematically showing the configuration of a sheet feeding device, and FIG. 3 schematically shows the configuration of the sheet feeding device showing a state where a pressing plate is at an upper limit position. FIG. 4 is a cross-sectional view as viewed from the side, FIG. 4 is a cross-sectional view as viewed from the side, schematically illustrating the configuration of the paper feeding device in a state where the pressing plate is at the lower limit position, and FIG. 6 is a perspective view showing a stopper and a stopper operation member in the sheet feeding device.

In FIG. 1, reference numeral 101 denotes an apparatus main body of an image forming apparatus such as a printer or a copying machine, and an image recording unit (not shown) is provided therein. Reference numeral 102 denotes a paper feeder to which the present invention is attached, which is mounted on the apparatus main body, and which stacks a large number of recording papers made of cut paper and supplies the recording paper to the image recording unit of the apparatus main body 101.

The configuration of the paper feeder 102 will be described with reference to FIGS. In the figure, 1 is a cassette, 2 is a paper feed roller, 3 is a pressing plate, 4 is an elastic member, 5 is a pressing plate operating member, 6 is a stopper, and 7 is a stopper operating member.

The cassette 101 has a flat rectangular box shape with an open upper surface and an upstream end in the recording paper feeding direction. As shown in FIG. 2, a large number of recording papers P made of cut paper are stacked. Be placed. The cassette 1 is attached to a sheet feeding frame 103 provided in the apparatus main body 101 from outside of the apparatus main body 101 in a state where the cassette 1 is inclined obliquely downward so that the downstream end in the recording paper feeding direction is downward. Have been.

The paper feed roller 2 is disposed at the center of the cassette 1 in the width direction of the cassette above the downstream end of the cassette 1 in the paper feeding direction, and extends in a direction perpendicular to the paper feeding direction (cassette width direction). A screw 12 is attached to a roller attachment portion 11a of the roller shaft 11 that is arranged in the vertical direction. The roller mounting portion 11a has a larger diameter than other portions of the roller shaft 11a, and the paper feed roller 2 has a semicircular shape having a larger diameter. By attaching the paper feed roller 2 to the roller mounting portion 11a, the paper feed roller 2 forms an eccentric cam together with the roller mounting portion 11a, and the recording paper P stacked on the pressing plate 3 in the course of one rotation by the roller shaft 11 is formed. This is successively fed out upon contact. The roller shaft 11 is rotatably supported by a bearing 13 provided on the apparatus main body 101, and the clutch spring 1 is driven by a solenoid 16 provided on the apparatus main body 101.
The rotation is transmitted from the drive gear 15 through the rotation gear 4 to make one rotation.

The pressing plate 3 is disposed so as to be overlapped on the upper side of the bottom portion in the inside, and both sides of the upstream end in the recording paper feeding direction are erected on the upper side. The recording paper feeding direction downstream end is located below the paper feed roller 2. That is, the pressing plate 3 is for placing the recording papers P stacked on the cassette 1, and as shown in FIGS. 2 and 3, the feed roller 2 is supported by the pivot 17 at the downstream end in the recording paper feeding direction. And swings between an upper limit position B contacting the sheet feeding roller 2 and a lower limit position A separated from the sheet feeding roller 2.

The elastic member 4 applies a force for swinging the pressing plate 3 upward to approach the paper feed roller, and here a conical coil spring is used. The elastic member 4 is arranged upright at the center in the cassette width direction below the downstream end of the pressing plate 3 in the recording paper feeding direction, and the lower end is supported by a receiving recess 18 formed on the bottom surface of the cassette 1. The upper end contacts and supports the lower surface of the pressing plate 3.

The pressing plate operating members 5 are formed in the form of levers arranged close to the inner surfaces of the side walls on both sides in the width direction of the cassette 1, and are arranged in a direction orthogonal to the recording paper feeding direction (cassette width direction). It is attached to a shaft 21 arranged along the shaft, and is provided so as to be able to swing vertically with the shaft 21 as a fulcrum. That is, as shown in FIGS. 2 and 3, the pressing plate operation member 5 is separated from the operating position C for forcibly swinging the pressing plate 3 to the lower limit position A with the shaft 21 as a fulcrum and the lower limit position A of the pressing plate 3. (Upper than the pressing plate 3 that has been swung to the upper limit position B). The pressing plate operating member 5 is held at the operating position C in a state where the distal end of the pressing plate operating member 5 is in contact with the plate surface of the pressing plate 3.
When the elastic member 4 is pushed by the elastic member 4 and swings upward, the distal end portion is pushed by the pressing plate 3 and swings upward to the non-operation position D.

The handle 22 is formed integrally with the one pressing plate operating member 5, and by operating the one pressing plate operating member 5 with the handle 22, the shaft 2 is moved.
The first and other pressing plate operation members 5 are caused to swing. When the pressing plate operating member 5 is in the operating position C by pressing down the pressing plate 3, the handle 22 is formed on the pressing plate operating member 5 by setting the direction so as to protrude upward (outside) from the cassette 1. Have been.

The stopper 6 operates when the pressing plate operating member 5 swings the pressing plate 3 to the lower limit position A, and the elastic member 4
Plate 3 in the direction of approaching paper feed roller 2 against the force of
This regulates the rocking motion. In this embodiment, the stoppers 6 are disposed above the pressing plate 3 at locations close to the inner surfaces of the side walls on both sides of the cassette 1, respectively, and are provided on the cassette side wall and the wall 1a formed in parallel with the cassette side wall. It is suspended and supported by the pivot 23 provided.

That is, the stopper 6 is provided in the manner shown in FIGS.
As shown in the figure, the pivot plate 23 is swingably hung by the pivot 23 located above the upper limit position B of the pressing plate 3 and is always given a downward swinging power by its own weight. When swinging to the position A, it swings downward and contacts the pressing plate 3 from above to restrict the swinging of the pressing plate 3 toward the paper feed roller 2 against the force of the elastic member 4. Between the lock position E and the release position F, which is placed on the pressing plate 3, is pushed up, swings upward, and lies away from the pressing plate 3. Here, the stopper 6 is a lock position E along a direction perpendicular to the plate surface of the pressing plate 3 at a position close to an end on the upstream side in the recording paper feeding direction with respect to a vertical line O passing through the pivot 23 pivotally supported. To restrict the movement of the pressing plate. A protrusion 6a is formed at the upper end of the stopper 6 so that a cam-shaped stopper operation member 7 described later abuts and swings. In addition,
The pressing plate 3 is formed with a hole 3a for allowing the protrusion 6a to escape when the stopper 6 is pushed up by the stopper and rides thereon.

The stopper operating member 7 is configured such that the paper feed roller 3
The stopper 6 is removed from the position for restricting the swing of the pressing plate 3 in the direction to approach the paper feed roller 2 before performing the operation of rotating and feeding out the uppermost layer of the stacked recording papers P. In this embodiment, the stopper operation member 7 is configured as a cam that rotates in conjunction with the rotation of the paper feed roller 2 and removes the stopper 6 from a position that restricts the swing of the pressing plate. That is, the stopper operating member 7 having this shape is a circular cam having a protruding portion 7a on a part of the circumference thereof, and is attached to the roller shaft 11 of the paper feed roller 2 so as to be integral with the paper feed roller 2. It is designed to be rotated. The feed roller 2 is rotated in synchronization with the feed roller 2 before the feed roller 2 comes into contact with the recording paper P stacked on the pressing plate 3 and is fed out. And the stopper 6 is pivoted upward with the rotation of the stopper 6 along with the rotation of the stopper 6.

Reference numeral 31 denotes a separation plate for separating the recording paper P fed by the paper feed roller 2 from the lower recording paper P.
Reference numeral 32 denotes a pad adhered to the separation plate 31, and reference numeral 33 denotes a spring that presses the separation plate 31 toward the paper feed roller 2.

The cassette 1 is adapted to accommodate various sizes of recording paper. Reference numeral 41 denotes a pair of left and right guides exclusively used for manual feeding. The guide films 42 are attached to the guide films 42 and attached to a sheet feeding table 43 exclusively used for manual feeding. 4
Reference numeral 4 denotes a pair of left and right guides, which are provided on the cassette 1. Reference numeral 45 denotes an auxiliary tray for holding recording paper of a long size such as A3 size, which is stored in the inside of the cassette 1 when ordinary A4 size recording paper P is used.

The operation of the paper feeder thus configured will be described.

FIG. 3 shows that the recording paper P is all fed out and the pressing plate 3
3 shows a state where the recording paper P is not placed. The pressing plate 3 is pushed up by the elastic member 4 and the paper feed roller 2 on the roller shaft 11 attached to the downstream end in the recording paper feeding direction.
Is contacted with the roller mounting portion 11a to which the upward swinging is restricted, and is at the upper limit position B. The pressing plate operating member 5 is in the non-operation position D, and the tip is separated from the pressing plate 3. The handle 22 provided on the pressing plate operation member 5 is located inside the cassette 1 in a state of being laid down. The stopper 6 is pushed up by the downstream end of the pressing plate 3 in the recording paper feeding direction, swings upward (toward the upstream side in the recording paper feeding direction) about the pivot 23, and lays at substantially the same height as the pivot 23. It is in the release position F in the state of being pressed. The protrusion 7a of the stopper operation member 7 composed of a cam is located on the downstream side in the rotation direction with respect to the protrusion 6a of the stopper 6. That is, the stopper 6 can swing about the pivot 23 in the up-down direction.

Then, as shown in FIG. 4, in order to replenish the recording sheet P to the pressing plate 3, the user holds the handle 22 lying down inside the cassette 1 by hand and moves the cassette 22 upward. Pull up. One pressing plate operating member 5
Swings downward from the non-operation position D to the operation position C about the pivot 21, and the other pressing plate operating member 5 also pivots to the operation position C via the pivot 21. In the process of swinging each pressing plate operating member 5, each tip comes into contact with the upper surface of the pressing plate 3 at the upper limit position B, and as each pressing plate operating member 5 swings downward to the operating position C, each of them moves. The tip pushes down the pressing plate 3 against the force of the elastic member 4. As a result, the pressing plate 3 swings downward about the pivot 17 from the upper limit position B to the lower limit position A.

Then, the stopper 6 placed on the downstream end portion of the pressing plate 3 in the recording paper feeding direction and lying at the upper limit position B moves the pressing plate 3 downward (toward the downstream side in the recording paper feeding direction). As it moves, it swings downward about the pivot 23 at the upper end. When the pressing plate 3 approaches the lower limit position A, the stopper 6 approaches a position perpendicular to the plate surface of the pressing plate 3, and the pressing plate 3 moves to the lower limit position A (a position parallel to the bottom surface of the cassette 1). ), The stopper 6 is at right angles to the plate surface of the pressing plate 3, and its tip comes into contact with the pressing plate 3 against the plate surface. That is, the stopper 6 pushes the pressing plate 3 at a lock position E along a direction perpendicular to the plate surface of the pressing plate 3 at a position closer to the upstream end in the recording paper feeding direction with respect to a vertical line passing through the pivot 23. Press from above. Therefore, the stopper 6 serves as a stick for the pressing plate 3 to lock the pressing plate 3 at the lower limit position A.

In this state, the user stacks many recording papers P and places them on the upper surface of the pressing plate 3. In this case, when the pressing plate operating member 5 swings the pressing plate 3 to the lower limit position, the stopper 6 swings downward by its own weight and abuts on the pressing plate 3 from above, and presses the pressing plate 3 of the elastic member 4. The swing in the direction approaching the paper feed roller 22 is regulated against the force and is held at the lower limit position A. Therefore, it is not necessary for the operator to press the pressing plate 3 to the lower limit position A so that the pressing plate 3 does not swing upward by hand when replenishing the recording paper P. Further, in this embodiment, the pressing plate operating member 5 is in the operating position, and the tip thereof has the pressing plate 3.
When the pressing plate 3 is pushed by the elastic member 4 and swings upward, the leading end portion is pushed by the pressing plate 3 and swings upward to the non-operating position B when the pressing plate 3 is pushed by the elastic member 4. In this case as well, it is not necessary to hold the pressing plate operating member 5 at the operating position C so as not to swing upward in order to press the pressing plate 3 to the lower limit position A. Can be enhanced. Also, the pressing plate operating member has a shape,
Operating position C by setting conditions such as pivot point position and center of gravity position
It is also possible to swing upward from the state in which the pressing plate 3 is pressed to return to the non-operation position B. In this case, however, the pressing plate operating member 5 is similarly pressed to press the pressing plate 3 to the lower limit position A. Does not need to be held at the operating position C so as not to swing upward.

Then, as described above, the solenoid 16 is driven to transmit the rotation of the drive gear 15 to the roller shaft 11 via the clutch spring 14. The roller shaft 11 rotates in the direction of the arrow shown in the figure, and the sheet feed roller 2 provided on the roller shaft 11 and the cam-shaped stopper operating member 7 also rotate in the same direction. In the course of this rotation, first, the protrusion 7a of the cam-shaped stopper operating member 7 is positioned at a right angle to the pressing plate 3 and the upper end of the stopper 6 at the lock position E where the pressing plate 3 is pressed from above. And presses the protrusion 6a downward with rotation. As a result, the stopper 6 is swung upward from the lock position E about the pivot shaft 23, and the tip end is disengaged from the plate surface of the pressing plate 3. For this reason, the pressing plate 3 is pushed by the elastic member 4 and swings upward from the lower limit position A about the pivot 17, so that the upper layer of the recording paper P stacked on the pressing plate 3 is attached to the roller shaft 11. It contacts the outer peripheral surface of the portion 11a. For this reason, the recording paper P, which is placed with the upward swing of the pressing plate 3 stopped, is pressed against the outer peripheral surface of the roller mounting portion 11 a of the roller shaft 11.

The rotation of the roller shaft 11 causes the outer peripheral surface of the roller mounting portion 11a to move in the circumferential direction. Instead, the outer peripheral surface of the cam-type paper feed roller 2 having a larger diameter is formed on the uppermost layer of the recording paper P. Contact Then, the uppermost recording paper P is fed toward the downstream side in the feeding direction by the rotation of the feed roller 3. Thereafter, each time the paper feed roller 2 makes one rotation, the uppermost recording paper P is fed one by one.

The stopper operating member 7 is pushed upward by the upwardly swinging pressing plate 3 and swings upward. The rotation of the roller shaft 11 causes the stopper 7 to swing on the protrusion 7a of the stopper 7 each time the stopper operation member 7 makes one rotation, but does not hinder the feeding of the recording paper P.

Here, before the operation of feeding the uppermost layer of the stacked recording paper P by rotating the paper feed roller 2 by one rotation,
Since the stopper operating member 7 removes the stopper from the lock position E for restricting the swinging movement of the pressing plate 3 toward the paper feed roller 2, the self-weight type stopper 6 stops at the lock position E after replenishing the recording paper. It is possible to prevent a situation in which the pressing plate 3 is kept locked at the lower limit position while keeping the state, and it is possible to prevent an error from occurring in image recording because the paper is not fed even when the recording paper is replenished.

In place of the self-weight type stopper, a type in which a force is applied toward the lock position E using an elastic member such as a torsion coil spring can be used. The effect can be obtained. Further, as in the prior art, after the recording paper is replenished, the operator sets conditions such as the pressing plate operating member (shape, pivot point position, center of gravity position, etc., and stops by itself while pressing the pressing plate at the operating position. It is not necessary to move the plate operating member) from the operating position C where the pressing plate 3 is pressed to the non-operating position D, so that workability can be improved.

In this embodiment, since the stopper 6 which is supported by hanging is used as the stopper 6, it is possible to prevent the operator from pressing the pressing plate operating member 7 to the operating position C when replenishing the recording paper. It can be realized with a very simple configuration in which the stopper hangs down by its own weight.

The stopper 6 extends in a direction perpendicular to the plate surface of the pressing plate 3 at a position closer to the end on the upstream side in the recording paper feeding direction with respect to a vertical line O passing through a pivot 23 for supporting the stopper 6. A position of the pressing plate 3 to restrict the movement of the pressing plate 3
Can be swung upward toward the upstream end in the sheet feeding direction, so that it is possible to provide a specific configuration capable of sufficiently exerting the function of the stopper.

It is also conceivable to use a means for displacing the stopper not at its own weight but with an elastic member so that the pressing plate at the lower limit position is returned to the upper limit position so as not to return to the upper limit position. There are the following problems in comparison. That is, it is necessary to provide a spring for displacement in addition to the stopper, and the number of parts is large. The spring force may be required to be larger than the elastic member that pushes up the pressing plate, and the spring may be increased in size. In order to remove the stopper from the position for pressing the pressing plate, it is necessary to apply a force greater than the spring force of the spring for displacing the stopper to the pressing plate. In the case where the stopper is removed from the position where the pressing plate is pressed by using a cam rotated by the shaft of the sheet feeding roller as in this embodiment, the spring for displacing the stopper acts as a resistance and the sheet feeding roller , A large load may be applied to the recording paper to adversely affect the feeding of the recording paper by the paper feed roller.

When the pressing plate operating member 7 is in the operating position C for forcibly swinging the pressing plate 3 to the lower limit position A, the handle 22 which is a part of the pressing plate operating member 7 projects outside the cassette 1. Since the pressing plate 3 is separated from the paper feed roller 2 and the recording paper P is not being supplied, it can be seen by looking at a part of the pressing plate operating member 5 protruding outside the cassette 1. The operation of the paper feeder is convenient.

The stopper operating member 7 is of a cam type which rotates in conjunction with the rotation of the paper feed roller 2 and removes the stopper 6 from the lock position E which restricts the swing of the pressing plate 3. It is possible to provide a specific configuration capable of sufficiently exhibiting the function.

The structure for supporting the stopper 6 is not limited to the above-described embodiment, but may be another type. For example, the stopper 6 is connected to a vertical line O passing through a pivot 23 for supporting the stopper 6.
Abuts on the downstream side of the sheet feeding direction at a position along a direction perpendicular to the plate surface of the pressing plate 3 to restrict the movement of the pressing plate 3 and record the pressing plate 3. It is provided so that it can swing upward toward the downstream end in the paper feeding direction. Further, the stopper 6 is provided so as to abut on the plate surface of the pressing plate 3 on a vertical line O passing through the pivot 23 for pivotally supporting the stopper 6 to restrict the movement of the pressing plate 3. These can provide a specific configuration capable of sufficiently exerting the function of the stopper 6.

It should be noted that the present invention is not limited to the above-described embodiment.
Various modifications can be made. For example, the present invention
It is effective to apply the present invention to a paper feeder that supplies recording paper to an image recording unit. However, the present invention is not limited to this. For example, the present invention can be applied to a paper feeder that supplies originals in a stacked state.

[0055]

According to the sheet feeding device of the first aspect of the present invention, when the pressing plate operating member swings the pressing plate to the lower limit position,
The stopper oscillates downward by its own weight and abuts against the pressing plate from above to restrict the oscillating movement of the pressing plate toward the paper feed roller against the force of the elastic member. It is not necessary for the operator to manually hold the pressing plate operating member to the operating position, so that the workability can be improved, and the work of the operator pressing the pressing plate operating member to the operating position when replenishing paper is avoided. This can be realized with a very simple configuration in which the stopper hangs down by its own weight.

According to the second to fourth aspects of the present invention, it is possible to provide a specific structure capable of sufficiently exhibiting the function of the stopper in addition to the effect of the first sheet feeding apparatus.

According to the fifth aspect of the present invention, the fact that the pressing plate is separated from the paper feed roller and the paper is not supplied is determined by observing a part of the pressing plate operating member protruding outside the cassette. The user can know and the operation of the paper feeder becomes convenient.

According to the paper feeding device of the sixth aspect, when the pressing plate operating member swings the pressing plate to the lower limit position, the stopper operates to approach the paper feeding roller against the force of the elastic member. Since the swing of the pressing plate in the direction is regulated, it is not necessary for the operator to press the pressing plate operating member to the operation position when replenishing the paper, so that the workability can be improved, and the paper feed roller can be used. Before performing the operation of rotating and feeding the top layer of the stacked paper, the stopper operation member removes the stopper from the position that regulates the swing of the pressing plate in the direction to approach the paper feed roller, so that the paper is replenished. After this, it is not necessary for the operator to move the pressing plate operating member from the operating position where the pressing plate is pressed by the hand to the non-operating position, thereby improving workability.

According to the seventh aspect of the present invention, it is possible to provide a specific configuration in which the stopper operating member can sufficiently exhibit its function.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an appearance of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a plan view schematically showing a configuration of the sheet feeding device in the embodiment.

FIG. 3 is a cross-sectional view schematically showing a configuration of the sheet feeding device according to the embodiment.

FIG. 4 is a sectional view schematically showing the configuration of the sheet feeding device according to the embodiment.

FIG. 5 is an exploded perspective view showing the sheet feeding device in the embodiment.

FIG. 6 is an exploded perspective view showing the sheet feeding device in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... cassette, 2 ... paper feed roller, 3 ... pressing plate, 4 ... elastic member, 5 ... pressing plate operating member, 6 ... stopper, 7 ... stopper operating member, 22 ... handle, 101 ... apparatus main body, 102 ... paper feeding Device: A: Lower limit position, B: Upper limit position, C: Operating position, D: Non-operating position, E: Lock position, F: Release position.

Claims (7)

[Claims] 1. A cassette for stacking and arranging sheets, a paper feed roller provided above the cassette for feeding the stacked sheets from the uppermost layer by rotation, and an upstream end in the sheet feeding direction of the cassette. A stack of paper stacked on the cassette is provided so as to be vertically swingable between an upper limit position pivotally supported by the sheet feed roller and a lower limit position separated from the sheet feed roller. A pressing plate, an elastic member that applies a force to swing the pressing plate upward to approach the paper feed roller and presses the paper placed on the press plate against the paper feed roller, and the pressing plate. A pressing plate operating member that is displaced between an operating position forcibly swinging to a lower limit position and a non-operating position distant from the lower limit position of the pressing plate; and a pivot shaft that is positioned above the upper limit position of the pressing plate. Droopable The pressing plate operating member is always provided with a downward swinging power by its own weight, and swings downward when the pressing plate operating member swings the pressing plate to the lower limit position, and contacts the pressing plate from above to perform the pressing. A sheet feeder, comprising: a stopper that restricts swinging of the plate toward the sheet feeding roller against the force of the elastic member, and swings upward to separate from the pressing plate. apparatus. 2. The stopper according to claim 1, wherein the stopper is located at a position closer to an upstream end in a sheet feeding direction with respect to a vertical line passing through the pivot for pivotally supporting the stopper, in a direction perpendicular to the plate surface of the pressing plate. 2. The sheet feeding device according to claim 1, wherein the pressing plate is in contact at a position to restrict the movement of the pressing plate, and is capable of swinging upward toward the upstream end of the pressing plate in the sheet feeding direction. 3. apparatus. 3. The stopper extends along a direction perpendicular to the plate surface of the pressing plate at a position closer to a downstream end in a sheet feeding direction with respect to a vertical line passing through the pivot axis for pivotally supporting the stopper. 2. The sheet feeding device according to claim 1, wherein the pressing plate is in contact at a position to restrict the movement of the pressing plate, and is capable of swinging upward toward a downstream end of the pressing plate in the sheet feeding direction. 3. apparatus. 4. The stopper restricts the movement of the pressing plate by abutting at a position along a direction perpendicular to the plate surface of the pressing plate on a vertical line passing through the pivot that pivotally supports the stopper. The sheet feeding device according to claim 1, wherein: 5. A part of the pressing plate operating member protrudes outside the sheet feeding cassette when the pressing plate operating member is in an operation position for forcibly swinging the pressing plate to a lower limit position. 2. The paper feeding device according to 1. 6. A cassette for stacking and arranging sheets, a paper feed roller provided above the cassette and feeding the stacked sheets from the uppermost layer every one rotation, and an upstream end in the sheet feeding direction. The part is pivotally supported by the cassette and is swingably provided in a vertical direction between an upper limit position where it comes into contact with the paper feed roller and a lower limit position where it is separated from the paper feed roller. A pressing plate on which the paper is placed, and an elastic member for applying a force to swing the pressing plate upward to approach the paper feed roller to press the paper placed on the press plate against the paper feed roller. A pressing plate operating member for displacing between an operating position for forcibly swinging the pressing plate to a lower limit position and a non-operating position remote from the lower limit position of the pressing plate; Swing to the lower limit position. A stopper that operates when the paper feed roller rotates one turn to prevent the pressing plate from swinging toward the paper feed roller against the force of the elastic member. And a stopper operating member that removes the stopper from a position that restricts swinging of the pressing plate in a direction to approach the sheet feeding roller before performing an operation of feeding the uppermost layer. 7. The stopper operation member according to claim 6, wherein the stopper operation member is a cam that rotates in conjunction with the rotation of the paper feed roller to remove the stopper from a position that restricts the swing of the pressing plate. Paper feeder as described.