JPS62249835A - Sheet feeder - Google Patents

Abstract

PURPOSE:To obtain a sheet feeder having a very simple construction and easy to manufacture by providing a suction cylinder with an upwardly inclined wall formed between a bottom wall and a front wall. CONSTITUTION:When a negative pressure generator is actuated to reduce the pressure in a suction chamber 9 of a suction cylinder 3 to a pressure lower than the atmospheric pressure, external air in the vicinity of an opening 17 is sucked into the suction chamber 9 through the opening 17. This suction causes the leading portion of the uppermost sheet of a sheet stack 1 on a sheet tray 2 to be sucked toward the suction cylinder 3, so that the sheet is adsorbed on an inclined wall 12 and a bottom wall 11 of the suction cylinder 3. At this time, as the uppermost sheet and the next sheet are widely spaced apart from each other, air blast from an air blower 31 flows through the space between the sheets to separate them.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a paper feed table on which a plurality of sheets of paper are stacked and placed in close proximity above the uppermost sheet of paper on the paper feed table. The present invention also relates to a paper feeding device of a type having an intake cylinder which has an intake chamber maintained at a pressure lower than atmospheric pressure and which sucks the uppermost sheet paper, and a paper feeder which feeds and covers the sucked sheet paper. In particular, the present invention relates to a paper feeding device used in devices and machines that use a large number of sheets of paper, such as printers, copiers, and facsimile machines.

[Prior Art] Conventionally, the above-mentioned type of paper feeding device has a vertically movable plate pivotally attached to the lower part of the intake cylinder, a paper feeding roller attached to this plate, and the plate moved downward. It is configured to suck the uppermost sheet paper on the paper feed tray, then return the plate to a horizontal position and feed the sheet paper by the paper feed roller.

[Problems to be Solved by the Invention] In the conventional paper feeding device as described above, a mechanism for pivoting the plate must be provided in the suction pipe, which makes the structure of the device complicated and If an air blowing device is provided at the front of the paper feeding tray to separate the topmost sheet on the paper feeding tray from the next sheet, the fed sheets will not collide with the air blowing device. However, there are drawbacks such as the need to move the entire intake cylinder further upwards to feed the sheet paper. Furthermore, since the uppermost sheet of paper that has been attracted is positioned approximately parallel to the next sheet of paper, there is a problem in that separation by air blowing cannot be performed effectively.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to eliminate the drawbacks and problems of the conventional paper feeding apparatus as described above, and to provide a simple and convenient paper feeding apparatus.

[Means for Solving the Problems] A paper feeding device according to the present invention includes a paper feeding tray on which a plurality of sheets of paper are stacked, and a paper feeding tray that is arranged close to and above the uppermost sheet of the paper feeding tray. It has an intake cylinder forming an intake chamber maintained at a pressure lower than atmospheric pressure, and an air blowing device disposed in the front portion of the paper feed table and blowing air substantially parallel to the surface of the topmost sheet of paper, The intake cylinder has an upwardly inclined inclined wall between the bottom wall and the front wall thereof, the inclined wall forms an intake opening, and the peripheral surface portion of the paper feed roller is rotatably provided in the intake chamber. protrudes from the air intake opening to the outside, and sucks the leading edge of the uppermost sheet of paper onto the inclined wall, and blows air between the uppermost sheet of paper and the next sheet of paper using the air blowing device. The method is characterized in that the uppermost sheet is fed by a feed roller, and the next sheet is separated.

[Function] With the above-described configuration, the uppermost sheet of paper on the paper feed table is attracted to the inclined wall of the suction cylinder, and in this state, the sheet of paper is fed forward and diagonally upward by the paper feed row. Also, during this suction, the device effectively blows air to separate the sheet from the next sheet.

[Example] The illustrated invention will now be described in detail.

The paper feeding device shown in FIG.
The apparatus has a paper feed table 2 on which paper sheets are placed in a stacked manner, and an intake cylinder 3 is fixed to the main body of the apparatus and arranged above the paper feed table 2.

The intake cylinder 3 has a vertically extending guide sleeve 5 fixed to its rear wall 4, and a shaft 6 is guided within the guide sleeve 5 so as to be movable in the vertical direction. A roller 7 is rotatably supported at the lower end of the shaft 6, and the roller 7 comes into contact with the uppermost sheet of paper on the paper feed table 2, causing the shaft 6 to respond to the vertical movement of the paper feed table 2. There is. The upper end of the shaft 6 is a photo interrupter device 8 attached to the rear wall 4 of the intake cylinder 3.
It is designed so that it can penetrate from below into the light-blocking path of The upper end of the photo-interrupter device 8 is located within the light-blocking path of the photo-interrupter device 8 to perform a light-blocking operation, and sends a signal generated by this light-blocking to a drive control device (not shown) for the paper feed tray 2 to send the signal to the upper end of the paper feed tray 2. It is supposed to stop moving. With such a configuration, the paper feed table 2 can always position the top sheet paper at the top sheet paper feeding position shown in the figure, regardless of the number of sheets placed on it during paper feeding operation. .

The intake cylinder 3 has an intake chamber 9 formed at its lower end, and the intake chamber 9 includes a rear wall 4, a front wall 10, a bottom wall 11, and an inclined wall 12.
and side walls 13 and 14 (FIG. 2), with the bottom wall 11 extending forward from the lower end of the rear wall 4 to the feed platform 2.
Extending substantially parallel to the uppermost sheet paper of the upper sheet paper 1,
The front end 15 of the bottom wall 11 terminates in an upwardly bent position. The inclined wall 12 extends rearward and downward from the lower end of the front wall 10 in a straight or curved manner, and its lower end 16 has an opening 1 extending laterally between it and the front end 15 of the bottom wall 11.
7 and terminates. The terminal ends of the bottom wall 11 and the inclined wall 12 forming these openings 17 are located at l? as shown in FIG. Jl! ! The projecting portions 11a and 12a protrude in an Il shape, facing each other, and constitute a guide pawl for preventing the paper sheet from being rolled into the opening 17, and a separation pawl for separating and guiding the sheet paper from the suction cylinder.

The bottom wall 1 is preferably spaced approximately 4 to 5 mff1 upwardly from the top sheet of paper 1 on the paper feed platform 2 when the paper feed platform 2 is in the top sheet feeding position. Ru.

As shown in FIG. 2, the openings 17 are made up of rectangular large openings 18 that are long in the feeding direction of the sheet paper 1 and small openings 19 that are smaller in area than the large openings 18 and are alternately arranged in the horizontal direction. A portion of the outer circumferential surface of the paper feed roller 20 protrudes outward from each large opening portion 18 . Each paper feed roller 20 is supported by @21 rotatably attached to the side walls 13 and 14 of the suction cylinder 3, and each paper feed roller 20 is integrally formed on one side thereof. The boss portion 22 is fixed at a predetermined position on the shaft 21 by screwing it to the shaft 21.

Furthermore, each paper feed roller 20 has a rubber ring 23 attached to its outer periphery, and the rubber ring 23 has grooves extending in the transverse direction on the entire outer periphery of the roller to prevent contact with the sheets 1 to 1. It is designed to increase the frictional force.

The shaft 21 is connected to a suitable rotary drive device and is adapted to be rotated counterclockwise as viewed in FIG. 1 at a predetermined speed.

The intake cylinder 3 forms a valve chamber 24 in the upper part of the intake chamber 9,
The valve chamber 24 has a rotary valve member 25 mounted therein,
The air flow inside the intake cylinder 3 can be blocked. Further, the intake cylinder 3 is connected to a negative pressure generator (not shown) in a portion above the valve chamber 24, and maintains the intake chamber 9 in the intake cylinder 3 at a pressure lower than atmospheric pressure through the valve chamber 24. It looks like this. The negative pressure generating device can be constructed by, for example, connecting the intake port of a blower to the upper part of the intake cylinder 3.

The paper feed tray 2 has an air blower at its front portion that acts to blow air in the direction of the arrow A almost parallel to the surface of the paper sheet 1 to separate the uppermost sheet paper from the next and lower sheets. Spraying rJ! 131 has been established.

With the configuration described above, the negative pressure generator operates and the intake cylinder 3
When the pressure in the air intake chamber 9 of the air intake chamber 9 decreases to a pressure lower than atmospheric pressure, external air near the opening 17 is drawn into the air intake chamber 9 through the opening 17. Due to this suction action, the front portion of the uppermost sheet of paper 1 on the paper feed tray 2 is sucked toward the suction cylinder 3 and is attracted from the inclined wall 12 to the bottom wall 11 of the suction cylinder 3. At this time, since there is a wide gap between the uppermost sheet and the next sheet, the air blowing from the air blowing device 31 blows through the space between these sheets and separates both sheets. Also, is this the next sheet paper number 1? This prevents frictional electrification and eliminates the harmful effects of frictional electrification that occurs at the gate between the sheet of paper and the paper below when it is fed out. When the lN 121 and the roller 20 are rotated almost simultaneously, the attracted sheet paper is fed obliquely upward along the inclined wall 12.

A sheet paper guide member 26 is attached to the front wall 10 of the intake pipe 3, and the guide member 26 is arranged so that its guide passage 27 is located on an extension of the outer surface of the inclined wall 12 of the intake pipe 3. There is. With this configuration, the sheet paper fed along the inclined wall 12 as described above is fed into the guide passage 27 of the guide member 26 from its leading end. Furthermore, paper feed rollers 28 and 29 are provided at the front portion of the guide member 26.
The paper feed rollers 28 and 29 are constantly rotated to receive the sheet paper fed to the guide path 27.
This sheet paper is fed further forward.

[Effects of the Invention] With the configuration described above, the present invention suctions the uppermost sheet of paper on the paper feed table without moving the suction pipe and moves the suctioned sheet paper along the inclined wall of the suction pipe. feed,
Therefore, the paper feeding device has an extremely simple structure and is easy to manufacture. Furthermore, separation from the next sheet of paper is effectively performed by air blowing.

[Brief explanation of drawings]

FIG. 1 is a cutaway side view of an example of a paper feeding device according to the present invention, and FIG. 2 is a bottom view of the paper feeding device of FIG. DESCRIPTION OF SYMBOLS 1... Sheet paper, 2... Paper feed stand, 3... Intake cylinder, 9... Intake chamber, 10... t [i wall, 11... Bottom wall, 12... Inclined wall,
17...Opening, 20...Paper feed roller.

Claims (1)

[Claims] a paper feed tray on which a plurality of sheets of paper are stacked; an intake cylinder that is disposed close to and above the uppermost sheet of the paper feed tray and forms an intake chamber maintained at a pressure lower than atmospheric pressure;
an air blowing device disposed in the front portion of the paper feed table and blowing air substantially parallel to the surface of the top sheet of paper, and an air intake pipe having an upwardly inclined slope between the bottom wall and the front wall thereof; The paper feed roller has a wall, the inclined wall forms an air intake opening, and a peripheral surface portion of a paper feed roller rotatably provided in the air intake chamber projects outward from the air intake opening, and the inclined wall forms a suction opening. The leading edge of the upper sheet is sucked, the air blowing device blows air between the uppermost sheet and the next sheet to separate the next sheet, and the uppermost sheet is separated by a paper feed roller. A paper feeding device characterized by feeding paper.