JPH082728A - Paper feeding device - Google Patents

Abstract

PURPOSE:To provide a paper feeding device which regardless of the number of contained paper sheets always holds a separation claw at an appropriate locking height and surely delivers the paper sheets one by one. CONSTITUTION:A paper tray 3 for laminating and placing specified paper sheets 1 is arranged swingably in the vertical direction around a base end part thereof as a center inside of a main body 2, separation claws 5 locked to both angle parts of the uppermost paper sheet 1 with a specified height are arranged at tip angle parts of the main body 2, and a claw supporting plate 7 equipped with a guide slit 8 extending in a rectilinear shape in the vertical direction is arranged turnably in the vertical direction around a rear end thereof as a center inside of the main body 2. A separation claw 5 is formed at an upper end of the claw supporting plate 7 and a guide pin 9 projected on a side of a tip of a paper tray 3 is engaged with the guide slit 8.

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, and more particularly,
Stack multiple sheets of paper and store them.
The present invention relates to a sheet feeding device for taking out sheets one by one and sending them to a predetermined printing position.

[0002]

2. Description of the Related Art Conventionally, for example, in various printers such as laser printers, copiers, offset printers, etc., a plurality of sheets of paper are stacked and stored, and the sheets are taken out one by one from the upper part and a predetermined size is obtained. Paper feeding devices for feeding to printing and copying positions are often used.

FIG. 3 and FIG. 4 show such a conventional sheet feeding device, in which an upper surface is opened and a predetermined sheet 1 is placed inside.
A box-shaped main body 2 for accommodating and stacking the sheets is provided. Inside the main body 2, a flat sheet tray 3 for placing the sheets 1 is arranged. This paper tray 3
Supports the support pin 4 attached to the base end of the main body 2
By being rotatably supported on both side surfaces, the support pin 4 is swingably arranged vertically.
On the lower surface side of the paper tray 3, a pressure spring (not shown) that constantly biases the paper tray 3 upward is provided.

Separation claws 5 which are locked at a predetermined height at both uppermost corners of the sheet 1 are provided at both corners of the tip of the main body 2, and above the main body 2. A paper feed roller 6 is rotatably arranged near the separation claw 5.

In such a conventional paper feeding device, predetermined papers 1 are stacked and placed on the upper surface of the paper tray 3, and the tip corners of the uppermost paper 1 are placed on the lower surface of the separation claw 5. The paper 1 is stored inside the main body 2 by being locked to the side.

As shown in FIG. 4, the uppermost sheet 1 is pressed below the sheet feeding roller 6 by the upward biasing force of the sheet tray 3, and in this state, the sheet feeding roller 6 is moved. When rotated, the upper sheet 1 is conveyed by the frictional force between the sheet feeding roller 6 and the sheet 1, but only the uppermost sheet 1 of the conveyed sheets 1 is conveyed by the separating claw 5. It is separated from the lower sheet 1 and sent out from the main body 2, and the sheet 1 is conveyed to a predetermined printing position.

When the remaining amount of the sheet 1 becomes small, the sheet tray 3 is swung upward around the support pin 4 due to the upward biasing force of the sheet tray 3. As shown in FIG. 3, always the topmost sheet 1
Will be pressed against the paper feed roller 6.

[0008]

However, in such a conventional sheet feeding device, as shown in FIG.
The inclination angle of the paper tray 3 is different between a state in which a large amount of paper 1 such as about 100 sheets is stored in the main body 2 and a state in which several sheets of paper 1 are stored in the main body 2 as shown in FIG. Since the position of the separation claw 5 is constant,
Depending on the number of stored sheets of paper 1, the topmost paper 1 and separation claw 5
There is a problem that the locking height between the uppermost sheet 1 and the separation claw 5 becomes incorrect, and as a result, the sheet 1 can be properly fed. There is a problem that the paper is lost or cannot be properly separated by the separation claw 5, and a plurality of sheets of paper 1 are sent out, resulting in a paper feed failure. This is particularly remarkable when, for example, a relatively thick sheet 1 having a thickness dimension of about 0.2 mm is fed.

The present invention has been made in view of the above-mentioned points, and even if the paper is relatively thick, the separation claw can always be held at an appropriate locking height regardless of the number of stored papers. An object of the present invention is to provide a sheet feeding device that can reliably feed sheets one by one.

[0010]

In order to achieve the above object, a paper feeding apparatus according to the present invention comprises a paper tray for stacking and placing predetermined paper sheets inside a main body having an open upper surface. The main body is provided so as to be swingable up and down about the base end, and the separation pawls which are locked to the corners of the uppermost sheet at a predetermined height are arranged at both corners of the front end of the main body. In a paper feeding device in which a paper feeding roller for feeding the uppermost sheet is rotatably disposed above the separating claw and in the vicinity of the separating claw, the separating claw is provided depending on the stacking amount of the sheets in the paper tray. It is characterized in that the uppermost sheet and the separation claw are operably formed so as to fall within a predetermined range depending on the swing position.

Preferably, a pawl support plate having a guide hole extending linearly in the vertical direction is provided inside the main body so as to be rotatable up and down about a rear end of the pawl support plate. The separation claw is formed at the upper end of the support plate, and a guide pin protruding laterally from the leading end of the paper tray is engaged with the guide hole.

[0012]

According to the paper feeding device of the present invention, the separation claw has a predetermined locking height between the uppermost sheet and the separation claw according to the swing position of the sheet tray depending on the stacking amount of the sheets. For example, when the remaining amount of paper on the paper tray decreases, the paper tray is swung upward, and the rocking operation of the paper tray causes the guide of the paper tray to move. The pin moves in an arc shape, which causes
As the guide hole follows the guide pin, the claw support plate is rotated, and the rotation height of the separation claw and the uppermost sheet is always maintained by the rotation of the claw support plate. , Which can be maintained at a height within a predetermined range.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

1 and 2 show an embodiment of a sheet feeding device according to the present invention, in which a predetermined sheet 1 is stacked and placed inside a box-shaped main body 2 whose upper surface is open. A flat paper tray 3 for placing the paper tray 3 is arranged. The paper tray 3 is biased upward by a pressing spring (not shown) and has a support pin 4 attached to the base end thereof. By being rotatably supported on both side surfaces of 2, the support pin 4 is swingably arranged vertically.

Further, in this embodiment, on both front sides of the main body 2, there are pawl support plates 7 formed in a substantially L shape along the front surface and the lower surface of the main body 2 vertically with the rear end as the center. The claw support plate 7 is rotatably mounted on the
Separation claws 5 that are engaged with the uppermost corners of the sheet 1 are provided at the upper ends of the sheets. A guide hole 8 extending linearly in the vertical direction is formed in the claw support plate 7, and the guide hole 8 has guide pins 9 projecting from both sides of the leading end of the paper tray 3. Are engaged. The guide pin 9 of the paper tray 3 is moved by the claw support plate 7 in accordance with the vertical swing motion of the paper tray 3.
It is moved along the guide hole 8 and the claw support plate 7 is rotated. Although the separating claws 5 are arranged on both sides of the main body 2 in the above embodiment, they may be formed on only one side of the main body 2.

Further, a paper feed roller 6 is rotatably disposed above the main body 2 and near the separating claw 5.

Next, the operation of this embodiment will be described.

In this embodiment, predetermined sheets of paper 1 are stacked and placed on the upper surface of the paper tray 3, and the tip corners of the uppermost paper 1 are locked to the lower surface side of the separation claw 5. Thus, the paper 1 is stored inside the main body 2. In this case, in this embodiment, the sheet tray 3 is tilted downward about the support pin 4 due to the stacking thickness of the sheets 1, and the guide pin 9 of the sheet tray 3 is provided with the claw support plate 7. The claw support plate 7 is located below the guide hole 8, whereby the claw support plate 7 is rotated clockwise in FIG. 2, and the engaging height between the separation claw 5 and the uppermost sheet 1 is predetermined. Held at the height of. The locking height between the separation claw 5 and the uppermost sheet 1 is, for example, 0.
In the case of about 2 mm, 0.5 to 2.0 mm is suitable.

Then, when the uppermost sheet 1 is pressed against the lower side of the sheet feeding roller 6 by the upward biasing force of the sheet tray 3, the sheet feeding roller 6 is rotationally driven.
The upper sheet 1 is conveyed by the frictional force between the sheet feeding roller 6 and the sheet 1, but only the uppermost sheet 1 of the conveyed sheets 1 is moved to the lower sheet 1 by the separating claw 5. The sheet 1 is separated and sent out from the main body 2, and the sheet 1 is conveyed to a predetermined printing position.

When the remaining amount of the paper 1 becomes small as the paper is fed in this way, the paper tray 3 is swayed upward with the support pin 4 as a center by the upward urging force of the paper tray 3. Since it will be moved, as shown in FIG.
The uppermost sheet 1 is always pressed against the sheet feeding roller 6. In this case, in the present embodiment, when the paper tray 3 is swung upward, the guide pin 9 of the paper tray 3 moves in an arc around the support pin 4, but the claw support Since the guide hole 8 of the plate 7 is formed in a linear shape, the claw support plate 7 is rotated counterclockwise in the figure when the paper tray 3 is swung upward. By such rotation of the claw support plate 7, the locking height between the separation claw 5 and the uppermost sheet 1 is reduced to about several sheets 1 as shown in FIG. 1, for example. Even if you do, you will always be kept at a constant height.

Therefore, in the present embodiment, the pawl support plate 7 is rotated in response to the swing of the paper tray 3 so that the separation height between the separation pawl 5 and the uppermost paper 1 is increased. ,
Since the sheet can be held at a constant height at all times, the separating effect of the separating claw 5 can be kept constant regardless of the remaining amount of the sheets 1, and as a result, the sheets 1 stacked on the sheet tray 3 can be kept. It is possible to reliably send the sheets one by one, and it is possible to reliably prevent the occurrence of a paper feed failure such that the sheets 1 are not sent or a plurality of sheets 1 are sent.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be made if necessary.

[0023]

As described above, in the paper feeding device according to the present invention, the locking height between the separation claw and the uppermost sheet is always within a predetermined range in response to the swing of the sheet tray. Since it can be held at the height, the separation effect of the separation claw can be kept constant regardless of the remaining amount of paper, and as a result, the sheets stacked in the paper tray can be reliably delivered one by one. Therefore, it is possible to reliably prevent the occurrence of a paper feeding failure such that the paper is not delivered or a plurality of sheets are delivered.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a sheet feeding device according to the present invention, in which several sheets are stacked.

FIG. 2 is a schematic configuration diagram of a sheet stacking state of a sheet feeding device of the present invention.

FIG. 3 is a schematic configuration diagram showing a stacked state of several sheets of a conventional sheet feeding device.

FIG. 4 is a schematic configuration diagram showing a state in which a large number of sheets are stacked in a conventional sheet feeding device.

[Explanation of symbols]

 1 Paper 2 Main Body 3 Paper Tray 4 Support Pin 5 Separation Claw 6 Paper Feed Roller 7 Claw Support Plate 8 Guide Hole 9 Guide Pin

Claims (2)

[Claims] 1. A paper tray for stacking and placing predetermined sheets of paper is disposed inside a main body having an open upper surface so as to be vertically swingable about a base end portion of the main body. Separation claws that are locked at a predetermined height at both corners of the uppermost sheet are arranged at the tip corners, and the uppermost sheet is delivered above the main body and near the separation claws. In a sheet feeding device in which a sheet feeding roller is rotatably arranged, the separation claw is provided with a height of engagement between the uppermost sheet and the separation claw depending on a swing position of the sheet tray depending on a stacking amount of sheets. A sheet feeding device, which is formed so as to be operable within a predetermined range. 2. A claw support plate in which a guide hole extending linearly in the vertical direction is formed inside the main body is disposed rotatably up and down about a rear end of the claw support plate. 2. The sheet feeding device according to claim 1, wherein the separation claw is formed at an upper end portion, and a guide pin protruding laterally from a front end portion of the paper tray is engaged with the guide hole.