JPS6315213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device, and more particularly to a paper feeding device that prevents double feeding and is used in copying machines.

Prior Art Conventionally, air is applied from the paper feeding direction side to the front surface of the upper part of the paper stacked on the elevator tray, which is arranged between the guide and the rear stopper guide and can move up and down, to prevent double feeding. BACKGROUND OF THE INVENTION A spray type paper feeding device is used in copying machines and the like. FIG. 1 of the supplementary drawings schematically shows an example of a conventional paper feeding device of this type, which is disposed between a front guide 1 and a rear stopper guide 2 and is arranged vertically. A movable elevator tray 3 is provided. At the top of the elevator tray 3, sheets 4 to be fed are stacked. An air nozzle 5 is disposed close to the front surface of the upper portion of the stacked sheets, and a vacuum belt 6 is further disposed close to the upper surface of the front end of the sheets in the paper feeding direction. This type of paper feeding device blows air from an air nozzle 5 to the front surface of the upper part of the stacked sheets 4, sending air between the sheets and completely separating the topmost sheet and the next sheet. The paper is separated into two sheets, and only the uppermost sheet is attracted to the vacuum belt 6 and then sent out, thereby preventing the sheets from being sent out in an overlapping state, that is, so-called double feeding prevention. However, in the structure of this conventional paper feeding device, the upper end of the rear stopper guide 2 is
Since it is simply in an upright state, when the stacked sheets 4 rise with the rise of the elevator tray 3 as the sheets are fed, the front surface of the upper part of the sheets is It often becomes like a step, as if it were being sequentially shifted backwards. In this condition, air nozzle 5
Even if you blow air at an angle from below to the front of the stacked paper, it is difficult for air to get between the top paper and the next paper, and the top paper and the next paper are completely separated. In the end,
As schematically shown in FIG. 2, the vacuum belt 6
It was often the case that the particles were absorbed and sent out.

OBJECTS OF THE INVENTION An object of the present invention is to provide a paper feeding device that solves the problems of the conventional device as described above and completely prevents double feeding.

Structure of the Invention According to the present invention, paper is fed to the front surface of the upper portion of the paper stacked on the elevator tray, which is disposed between the front guide and the rear stopper guide and is movable up and down, in order to prevent double feeding. In a sheet feeding device of the type that blows air from the direction side, a portion of the rear stopper guide above the upper end of the front guide is formed so as to gradually protrude toward the sheet feeding direction side. According to the present invention, the upper part of the rear stopper guide is formed in this way, so that when the stacked sheets of paper rise as the elevator tray rises as the paper is fed, the upper parts of the rear stopper guide Since the sheets are successively pushed forward by the protruding shape of the upper end, the front surfaces of the upper portions of the sheets are always shaped to be located at about the front end of the upper sheet. Therefore, when air is blown against the front surface of such stacked papers, air is easily introduced between each paper, and the papers are completely separated, and only the top paper is attracted by the vacuum belt, etc. It will be adsorbed by the transfer device and sent out.

Embodiments Next, the present invention will be described in more detail with regard to embodiments of the present invention based on FIGS. 4 to 7 of the accompanying drawings.

FIG. 4 schematically shows the configuration of a paper feeding device as an embodiment of the present invention. The paper feeding device of this embodiment, like the conventional paper feeding device described above, has a front guide 11, a rear stopper guide 12, and is arranged between the front guide 11 and the rear stopper guide 12 and moves up and down. Uru elevator tray 13,
An air nozzle 15 is disposed close to the front surface of the upper part of the sheets 4 stacked on the elevator tray 13, and a vacuum belt 16 is disposed close to the upper surface of the front end of the sheets 4 in the paper feeding direction. It is mainly equipped with. According to the present invention, a portion 12A of the rear stopper guide 12 above the upper end 11A of the front guide 11 is inclined so as to gradually protrude toward the paper feeding direction.

In the paper feeding device having such a configuration, as the paper is fed, the elevator tray 13 is automatically raised to a position where the top surface of the topmost paper 4 stacked thereon turns on the micro switch 17. However, when the stacked paper 4 rises due to the rise of the elevator tray 13,
The upper part of these sheets is attached to the rear surface fixing guide 12.
The front surfaces of the upper portions of the sheets of paper 4 are
As shown in an exaggerated manner in FIG. 5, the shape is such that it is always located near the front end of the upper sheet of paper. When air is blown upward from the air nozzle 15 at an angle to the front surface of such stacked sheets, air is introduced between each sheet of paper, as schematically shown in FIG. 6, and the sheets are completely separated. Then, only the uppermost sheet of paper is attracted to the vacuum belt 16 and sent out.

In the embodiment shown in FIG. 4, the upper end of the rear stopper guide 12 is simply inclined in the paper feeding direction, but as partially shown in FIG.
The front surface of the portion 12A' above the upper end 11A of the front guide 11 of 2' may be formed into an arc shape so as to gradually protrude toward the paper feeding direction. In the embodiment shown in FIG. 7, the height position 1 of the upper end 11A of the front guide 11 is
An arcuate surface 12A'' having a radius R, e.g. 75mm, which touches a point L, e.g. 5mm below 1A', is formed on the front surface of the upper portion 12A' of the rear stopper guide 12'.Such an arcuate surface 12A'' is convenient because the stacked sheets 4 can be guided upward more smoothly.

Effects of the Invention According to the configuration of the paper feeding device of the present invention, as described above, air from the air nozzle is reliably introduced between each of the sheets in the upper part of the stacked sheets, and each sheet is completely separated. As a result, only the topmost sheet of paper is attracted to the vacuum belt and sent out, which completely prevents so-called double feeding, in which sheets are sent overlapping each other. Problems such as clogging will no longer occur.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a conventional paper feeding device;
2 is a schematic diagram showing an example of the operating state of the paper feeding device shown in FIG. 1; FIG. FIG. 4 is a schematic diagram showing a paper feeding device as an embodiment of the present invention, and FIG. 5 is similar to FIG. FIG. 6 is a schematic partial view illustrating the operating state of the paper feeding device shown in FIG. 4, and FIG. 7 is a schematic diagram showing the shape of the rear stopper guide of the paper feeding device as another embodiment of the present invention. It is a partial diagram. 4...Paper, 11...Front guide, 11A...
Upper end, 12... Rear stop guide, 12A... Upper part of rear stop guide, 13... Elevator tray, 15... Air nozzle, 16... Vacuum belt, 17... Micro switch, 12'...
Rear stop guide, 12A'... Upper part of rear stop guide, 12A''... Arc surface.

Claims (1)

[Claims] 1 Elevator tray 1 arranged between the front guide 11 and the rear stopper guide 12 and capable of moving up and down
In the paper feeding device of the type that blows air from the paper feeding direction side to the front surface of the upper part of the paper 4 stacked on top of paper 4 to prevent double feeding, the front guide of the rear stopper guide 12 A paper feeding device characterized in that portions 12A and 12A' above an upper end 11A of 11 are formed so as to gradually protrude toward the paper feeding direction.