JP3449149B2 - Paper feeder - Google Patents

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 used in copying machines, printers, facsimiles and the like.

[0002]

2. Description of the Related Art In a conventional sheet feeding device, Japanese Patent Laid-Open No. 7-
As disclosed in 228375, a separation claw for separating sheets is generally movable up and down. If the separation pawl is fixed, the paper will not easily rise to the paper feed position where the paper feed roller is located when the stacking capacity of the paper becomes very small, but if the separation pawl can move up and down, the separation pawl will escape upward. The paper can be reliably raised to the paper feed position with. Moreover, the pressing pressure of the separating claw, which tends to be low when the amount of paper loaded becomes small, ensures the necessary pressing pressure by the own weight of the separating claw that can move up and down to reliably press the paper. In this way, in the paper feeding device in which the separating claw can be moved up and down, the separating claw surely presses the paper from the upper side to prevent the paper from slipping into the gap between the separating claw. It is possible to suppress the occurrence of.

[0003]

However, in the above-described conventional sheet feeding device, since the separating claw is configured to be movable up and down, accuracy of parts is required, and the separating claw rebounds to the unit price of each part and As the number of points increases, the number of assembling steps also increases, so there is a problem that it is difficult to reduce the production cost.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a sheet feeding device in which the separation claw is fixed so that the number of parts of the separation claw is reduced and the production cost is reduced.

[0005]

In order to solve this problem, the present invention provides a pair of left and right separating claws for feeding a tray with a leading edge regulating portion for regulating the leading edge of a sheet and an upper surface retaining portion for pressing the upper surface of the sheet. together provided the paper side, the sheet on the tray to a sheet feeding apparatus having a tray plate for pressing the upper surface pressing portion of the separating claw, to secure the separation claw in the tray, cutting the corners of the separation claw side of the tray plate Notch to separate the tray plate from the separation claw,
The tray plate escapes the regulation of the upper surface pressing portion of the separation claw so as to be able to rise to the paper feeding position, and the notched portion of the tray plate
The area near is raised above the surrounding area .

According to the present invention, it is possible to provide a sheet feeding device in which the separation claw is of a fixed type, the number of parts of the separation claw is reduced, and the production cost is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the invention according to claim 1 of the present invention, a pair of left and right separating claws having a leading edge regulating portion for regulating the leading edge of the sheet and an upper surface retaining section for pressing the upper surface of the sheet are fed to the tray. A sheet feeding device having a tray plate that is provided on the tray side and presses the paper on the tray against the upper surface pressing portion of the separation claw, and fixes the separation claw to the tray to prevent movement and to separate the tray plate. The tray is separated from the separating claw by notching the corner on the claw side so that the tray plate can escape the regulation of the top pressing part of the separating claw and rise to the paper feeding position. Since the performance can be obtained by the fixed type, the fixed type of the separating claw can reduce the number of parts of the separating claw and can also reduce the required accuracy of the parts of the separating claw.

According to a second aspect of the present invention, in the first aspect of the invention, the vicinity of the notch on the separation claw side of the tray plate is notched and raised from the surroundings. Since the corners of the separated paper are bent by the step between the separation claw and the raised portion of the tray plate, the pressing force of the separation claw is increased by the repulsive force of the paper, and the tray plate itself is also separated from the raised portion and other parts. Due to the step, the corner of the sheet bends in a gentle arc with the raised portion as the apex, so that the sheets can be smoothly separated at the time of feeding and the double feeding of sheets can be prevented.

According to a third aspect of the present invention, in the invention according to any one of the first and second aspects, the tray plate is provided with a horizontal groove inside the tip regulating portion of the separating claw. Since the sheet is configured to be caught in the groove of the separation claw, it has an effect of preventing the sheet from slipping in.

Embodiments of the present invention will be described below. (Embodiment 1) The outline of one embodiment of the present invention is that the separation claw that was conventionally movable is fixed, and the structure of the tray plate and the separation claw is devised to solve the problem caused by the fixed type. It was solved by that. The structure of the tray plate avoids pressing the tray plate against the separation claw by notching the corner on the separation claw side,
Even if the paper becomes very small, it is designed so that it can always be lifted to the paper feed position. Also, by raising the vicinity of the notched corner of the tray plate from the surroundings, the stacked sheets are bent at the step between the separation claw and the raised part, so that the pressing force of the separation claw is increased by the repulsive force of the paper. You can Even on the tray plate side, due to the step between the raised portion and the other portion, the ridge is used as a vertex in the vicinity of the corner of the paper to bend and bend so that the paper is smoothly separated during paper feeding and double feeding. Has been devised so that this does not happen. The structure of the separating pawl is generally horizontal to the tray plate inside the leading edge regulating part that regulates the leading edge of the paper in order to prevent the paper from slipping into the separating pawl when the stacking amount of the paper becomes very small. A special groove is provided so that the leading edge of the paper can be caught in this groove so that it will not go further. Hereinafter, details of an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a plan view of an essential part of a sheet feeding device according to an embodiment of the present invention, FIG. 2 is a sectional view of an essential part of a sheet feeding device according to an embodiment of the present invention, and FIG. FIG. 3 is a front view of the main parts showing the shape of the tray plate of the paper feeding device according to the embodiment. FIG. 4 is a perspective view of a separating claw of a sheet feeding device according to an embodiment of the present invention, and FIG. 5 is a perspective view of a main part of a tray plate of the sheet feeding device. FIG. 6 is a side view of the separation claw of the sheet feeding device according to the embodiment of the present invention.

1 and 2, a separating claw 3 is provided symmetrically on the sheet feeding unit side of the tray 2 in the sheet feeding device 1, and the separating claw 3 is movable in a vertically movable manner of the conventional example. Unlike the fixed type, it is fixed to the tray 2. When the separation claw 3 is fixed, various problems occur as compared with the conventional example, but this problem can be solved by devising the structure of the separation claw 3 and the tray plate 4 as described below.

The tray 2 is provided with a tray plate 4 for lifting the front portion of the stacked sheets 5 (on the side of the separating claw 3) to a position where it comes into contact with a sheet feeding roller 6 which is a sheet feeding position. 4 is designed to be lifted by the force of the spring 7. The structure of the tray plate 4 is such that the corners on the side of the separation claw 3 are cut out as shown in FIG.
Make sure that the corners of the
Since they are only separated by about mm, how to cut out the corners of the tray plate 4 largely depends on the shape of the separating claw 3.
When the fixed separation claw 3 is used, it is difficult for the paper 5 to rise to the paper feeding position when the stacking amount of the paper 5 is very small. However, in the embodiment of the present invention, the tray plate 4 has a square shape. As shown in FIG. 2, the separation claw 3 has a notched structure.
It is possible to raise the sheet 5 without hitting the sheet, push up the sheet 5 to a predetermined sheet feeding position, and bring the sheet 5 into contact with the sheet feeding roller 6. By notching the corners of the tray plate 4 in this manner, the function of pushing up the sheet 5 to the sheet feeding position can be ensured similarly to the conventional vertically movable separating claw.

As shown in FIGS. 3 and 5, the tray plate 4 has a structure in which raised portions 8 are provided at both ends (near the notches). Due to the structure of the tray plate 4, the sheets 5 stacked on the tray plate 4 are pressed by the upper surface pressing portion 3a of the separation claw 3 at the most end portion thereof, and the raised portion 8 of the tray plate 4 slightly near the center thereof. Since it is lifted, the pressing force of the separation claw 3 can be increased by the repulsive force of the sheet 5. By thus providing the raised portions 8 on both ends of the tray plate 4, the pressing pressure of the separating claw 3 can be secured similarly to the vertically movable separating claw of the conventional example. Further, the paper 5 is pressed by the paper feed roller 6 which is in contact with the center thereof and is bent so as to draw a gentle arc, so that the papers 5 are easily separated from each other near the corners, and the multi- feeding is performed. It can be prevented.

The separating claw 3 is of a fixed type as described above, but its structure is, as shown in FIGS. 4 to 6, substantially horizontal to the tray plate 4 inside the leading edge regulating portion 3b for regulating the leading edge of the sheet 5. Various grooves 3c are provided. This is because when the stacking amount of the paper 5 becomes small, the waist of the paper 5 tends to be weak and the leading end thereof hangs down as shown in FIG. 6, so the leading end of the paper 5 is dropped into the groove 3c and slips into the separation claw 3. This is to prevent the occurrence of a paper feed error by stopping the paper feed. By thus providing the horizontal groove 3c in the tray plate 4 inside the tip regulating portion 3b of the separation claw 3, the paper 5 is prevented from slipping into the separation claw 3 in the same manner as in the conventional separation claw capable of moving up and down. It can be prevented. The shape of the groove 3c is not limited to the shape shown in FIGS. 4 to 6, and may be any shape as long as the sheet 5 can be prevented from slipping in.

Finally, the paper feeding state of the paper feeding device according to the embodiment of the present invention will be described. The sheets 5 stacked on the tray plate 4 are pushed up by the force of the spring 7 to reach the sheet feeding position and come into contact with the sheet feeding roller 6. When the paper feed roller 6 rotates, the paper 5 is separated from the separation claw 3 by the frictional force of the paper feed roller 6 and is fed forward. At this time, paper 5
Is in a state of being sufficiently separated in the vicinity of the raised portion 8 of the tray plate 4, so that a plurality of sheets will not be overlapped and fed (double feeding), and will not be dipped because it will be caught in the groove 3c of the separation claw 3. Sheets are fed one by one with certainty.

In this way, according to the present invention, even if the separation pawl is fixed, the performance equivalent to that of the conventional movable type can be maintained. Therefore, by making the separation pawl fixed, the number of parts of the separation pawl is reduced and the production cost is reduced. Can be reduced.

[0018]

As described above, according to the present invention, a pair of left and right separating claws having the leading edge regulating portion for regulating the leading edge of the sheet and the upper surface pushing portion for pushing the upper surface of the sheet are provided on the sheet feeding section side of the tray. A sheet feeding device having a tray plate that presses the paper on the tray against the upper surface of the separating claw, and fixes the separating claw to the tray to prevent it from moving, and the corner of the tray plate on the separating claw side. The tray plate and the separation claw are separated by notches to allow the tray plate to escape the regulation of the top pressing part of the separation claw and rise to the paper feeding position, so that the same performance as the movable type can be fixed. Since the separation pawl is fixed, the number of parts of the separation pawl can be reduced and the production cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a sheet feeding device according to an embodiment of the present invention.

FIG. 3 is a front view of a main part showing the shape of a tray plate of the paper feeding device according to the embodiment of the invention.

FIG. 4 is a perspective view of a separation claw of the sheet feeding device according to the embodiment of the present invention.

FIG. 5 is a perspective view of a main part of the tray plate of the sheet feeding device according to the embodiment of the present invention.

FIG. 6 is a side view of the separation claw of the sheet feeding device according to the embodiment of the present invention.

[Explanation of symbols]

1 Paper feeder 2 trays 3 separate nails 3a Upper surface pressing part 3b Tip regulation part 3c groove 4 tray plates 5 sheets 6 paper feed rollers 7 spring 8 ridge

Claims (2)

(57) [Claims] 1. A pair of left and right separating pawls having a front end restricting portion for restricting the front end of the paper and an upper surface pressing portion for pressing the upper surface of the paper are provided on the paper feeding portion side of the tray, and the paper on the tray is A sheet feeding device having a tray plate to be pressed against the upper surface pressing portion, wherein the separation claw is fixed to the tray, and the corner of the tray plate on the separation claw side is cut away to separate the tray plate and the separation claw. Allowing the upper surface of the separating claw to escape from the regulation and to raise to the paper feeding position, and raising the vicinity of the notched part of the tray plate above the surroundings.
A paper feeding device characterized by 2. The sheet feeding device according to claim 1 , wherein a horizontal groove is provided in the tray plate inside the tip regulating portion of the separation claw.