JPH0147368B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a paper separation mechanism in a paper feeding device such as a copying machine or a printing machine. In a paper feeding device that feeds sheets one by one from the bottom surface of the paper stacking section using airflow flowing toward the feeding means, separating and feeding of sheets is possible by adjusting the air flow rate according to the amount of paper. The present invention relates to a paper separation mechanism that performs paper feeding.

[Prior art]

In general, this type of vacuum feeder type paper feeding device has a feeding means 2 connected to the feeding side bottom plate 1a of a paper feeding tray 1, as shown in FIG. An air stream is ejected from a nozzle 4 attached to an air chamber 3 disposed above toward the feeding means 2, and the air stream is used to feed sheets one by one from the bottom surface of the paper group 5. The structure is such that Therefore,
In this type of paper feeding device, there is an important relationship between paper separation and the amount of air. Therefore, in conventional paper feeding devices, this has been done by adjusting the amount of air coming out of the nozzle 4. In this case, an opening 6 is bored in the rear wall 1b of the paper feed tray 1;
This prevents the paper from flapping when a small amount of paper is used. However, a large number of paper groups 5
When a large amount of paper is stored, a large amount of air is required to levitate the large amount of paper, which may cause noise. Further, if the amount of air is reduced in order to prevent noise, there are disadvantages such as making it impossible to handle a large amount of paper.

[Purpose of the invention]

The present invention has been developed in view of the above circumstances, and it is possible to keep the amount of air ejected constant, control the amount of air according to the amount of paper, and effectively utilize the air flow, such as by using bounced air flow. The purpose of this is to enable smooth flotation and handling of paper regardless of the amount of paper.

[Structure of the invention]

The present invention provides a paper feeding device that feeds sheets one by one from the bottom surface of a paper stacking section by using airflow flowing toward a feeding means connected to a feeding side bottom plate of a paper feeding tray. A valve that can control the opening and closing of this opening is installed in an opening drilled in the rear wall of the tray, and an opening/closing means that controls the opening and closing of the valve is connected to a paper amount detection means. The present invention is characterized in that the paper is separated and fed while controlling the opening and closing of the valve according to the amount of paper.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a schematic cross-sectional view of a paper feeder having a paper separation mechanism according to the present invention.The structure of its main parts is the same as that of the conventional vacuum feeder type paper feeder described above, and the copy paper A paper feed tray 1 that accommodates a group of paper sheets 5, a feeding means 2 connected to the feeding side bottom plate 1a of the paper feeding tray 1, and an air supply source (not shown) located above the feeding means 2. The nozzle 4 injects an air stream from the connected air chamber 3 toward the feeding means 2. In this case, the feeding means 2 includes a porous endless belt 9 installed between a pair of rollers 7 and 8, and a porous endless belt 9 disposed on the inner periphery of the belt 9 to eject from the nozzle 4. It is composed of an air chamber 10 that sucks air.

On the other hand, as shown in FIG. 3, a plurality of openings 6, 6, . 6, 6... are horizontal shafts 11 on the outside of the rear wall 1b.
The opening and closing of the valve 12 is controlled by a valve 12 whose upper end is pivotally mounted. in this case,
A horizontal shaft 11 that pivotally supports the valve 12 projects toward one side of the valve 12, and a solenoid 14, which is a valve opening/closing means, is connected to this projecting portion via an operating piece 13 that projects from the horizontal shaft 11. A tension spring 16 is tensioned between the tip of the operating piece 13 and the copying machine main body 15, and the tension force of the tension spring 16 allows the valve 12 to be closed at all times. Further, the solenoid 14 is electrically connected to a micro switch 17 which is a paper amount detection means for detecting the amount of paper group 5 accommodated in the paper feed tray 1. It is designed to operate by receiving electrical signals from the

Next, the operation mode of the paper separation mechanism of the present invention will be explained.

When an operator sets paper 5 on paper feed tray 1 and operates the copying machine, air is first jetted out from nozzle 4 in air chamber 3. At this time, the amount of air is discharged regardless of the feeding of the paper 5. In this state, the microswitch 17 detects the paper 5, the solenoid 14 is turned off, and the valve 12 is closed by the tension spring 16.
Therefore, the air ejected from the nozzle 4 collides with the rear wall 1b and the valve 12 and rebounds, causing the air to eject from the nozzle 4.
The air ejected from the paper 5 and the rebound air combine to give a strong buoyancy force to the paper 5, allowing the paper 5 to be separated smoothly.

Therefore, the feeding means 2 can feed the sheets one by one from the bottom surface of the sheet group 5.

As described above, when sheets are fed one by one from the bottom surface of the sheet group 5, the amount of sheets decreases and the amount of sheets is no longer detected by the micro switch 17. Solenoid 14 receives the electrical signal at this time.
operates ON, and valve 1 resists tension spring 16.
2 (see Figure 6). Therefore, some of the air ejected from the nozzle 4 escapes from the openings 6, 6, . . . and reduces the flotation force of the paper 5. Therefore, even when the amount of paper is small, the paper 5 does not flap around in the paper feed tray 1 and is smoothly separated and fed.

〔Effect of the invention〕

As described above, according to the paper separation mechanism of the present invention, the opening and closing of the opening formed in the rear wall of the paper feed tray is controlled by the valve, and the opening/closing means for controlling the opening and closing of the valve and the paper amount detection means Since it is electrically connected to the paper, it is possible to keep the amount of air constant and control the amount of air according to the amount of paper. Not only can this be done smoothly, but also paper can be separated and fed smoothly regardless of the amount of paper. In addition, excellent effects such as being able to solve the problem of noise in conventional vacuum feeder type paper feeding devices of this kind can be obtained, so that its utility value is remarkable.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a paper separation mechanism of a conventional paper feeding device, FIG. 2 is a schematic sectional view of a paper feeding device having a paper separation mechanism of the present invention, and FIG.
FIG. 4 is a side view of FIG. 3, and FIGS. 5 and 6 are explanatory views showing different operating modes. Symbol explanation, 1...Paper feed tray, 1a...Floor board,
1b... Rear wall, 2... Feeding means, 3... Air chamber,
4... Nozzle, 6... Opening, 11... Horizontal axis, 12
... Valve, 13 ... Operation piece, 14 ... Solenoid (valve opening/closing means), 16 ... Tension spring, 1
7...Micro switch (paper amount detection means).

Claims (1)

[Claims] 1. A feeding means is arranged in series with the bottom plate of the feeding side of the paper feeding tray, and one sheet of paper is loaded from the bottom surface of the paper stacking section by using the airflow flowing from above the feeding side toward the feeding means. In a paper feeding device that feeds paper every time, an opening is formed in the rear wall of the paper feeding tray, and a valve that can control the opening and closing of this opening is installed, and an opening/closing means for controlling opening and closing of the valve and a paper feeding device are provided. A paper amount detection means for detecting the amount of paper stored in the tray is connected to separate and feed the paper while controlling opening and closing of the valve according to the amount of paper in the paper feed tray. A paper separation mechanism in a paper feeding device, characterized in that: