JPH0285868A - Paper braking device - Google Patents

Abstract

PURPOSE:To reduce the cost of the temporary stop device of a cut paper and to enhance its reliability by rotatably supporting a lever to be engaged with the cut paper advancing on a tray and an arm having a right angle to the lever, and installing plural units of the devices in the direction at right angles to the advancing direction. CONSTITUTION:When the paper 5 advances on the tray 1 and comes into contact with the vertical lever 21, the T-shaped paper braking device 2 for stopping the paper 5 until the printing on the reverse side has been finished is turned in the direction of an arrow around the shaft 4 at a speed higher than that of the paper 5, because it is made of plastics or the like and smaller in equivalent mass. The arm 22 extending almost at a right angle to the level 21 turns downward and presses the paper 5 to stop it. A balancer 23 has an action of positioning the lever 21 downward. Plural units of the devices are arranged in the direction at right angles to the advancing direction of the paper 5, thus permitting the posture of the paper to be easily, stably and precisely held on the tray 1 without requiring power or the like for pressing the paper to the reference face.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a paper braking device when a copying machine or the like temporarily stops to reverse the paper after printing on one side when printing on both sides of cut paper (copying). It is.

[Background of the invention]

When printing on both sides of cut paper using the electrostatic image printing (copying) method, transferring and fixing one side and then transferring and fixing the other side, it is necessary to reverse the paper, so it is necessary to stop the paper.
This is followed by an operation to feed the paper in the opposite direction. This mechanism achieves the above function by pulling the paper in while holding it on the belt by suction when opening 61-282252, and by rotating the belt in the opposite direction when ejecting the paper. It is a complex and expensive device because it must be controlled accordingly. - There is a simple tray (Receiver II) as a temporary holding device, but unlike the previous device, the paper is not held between the trays when stored, so the holding position of the paper is unstable and the print quality after one sheet is ejected from the device. There was a problem. Therefore, in order to stabilize the paper posture within the toner, it is necessary to provide a reference surface and add a paper posture correction device that presses the paper against the reference surface. Particularly in the case of high-speed printing, the speed at which the paper penetrates the toner is too high, so it collides with the reference surface, and the amount of rebound is large, making it difficult to obtain a stable posture even with the paper posture correction device.

[Purpose of the invention]

An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a high-performance and inexpensive device.

[Summary of the invention]

The present invention utilizes the kinetic energy of the paper entering the tray to urge the paper braking device to rotate, stop the rotation, and at the same time stop the movement of the paper by clamping the paper on the tray surface. The shape and position of the paper braking device have been devised in a similar manner.

[Embodiments of the invention]

The figures show specific embodiments of the present invention.

Reference numeral 1 denotes a tray in which paper is held on the front side until printing on the back side starts. 2 is a paper braking device and is rotatably held by a shaft 4 fixed to a support member 3 fixed to the tray 1. A lever 21 extends downward from the center of the paper braking device 2 and extends downward from the surface of the tray 1. Furthermore, the paper braking device 2 has an arm 22 located substantially perpendicular to the lever 21, and is provided with a normal distance from the surface of the tray 1. The paper braking device 2 has a balancer 23 symmetrically to the arm 22 with the lever 21 at the center so that the lever 21 is normally positioned in the vertical direction.

When the paper 5 enters the tray 1, it comes into contact with the lever 21. Compared to the paper 5, the paper braking device 2 is designed to reduce the equivalent mass (moment of inertia ÷ square of the distance from the center of rotation to the paper contact position on the lever 21) at the contact position, that is, to reduce the equivalent mass of the shaft 4 at the contact position. Because it is thin in the axial direction and made of plastic etc. with low specific gravity,
The paper braking device W2 rotates around the shaft 4 at a higher speed than the paper 5 at the contact position.

Therefore, the arm 22 rotates downward. Since the paper 5 moves in the same relative position as the lever 21, the paper 5 is held between the arm 22 and the surface of the tray 1 while the amount of movement of the paper 5 on the tray surface after contacting the lever 21 is extremely small. be done.

This state is shown by a broken line. By arranging a plurality of paper brake devices 2 perpendicular to the paper moving direction, even if the paper 5 entering the tray 1 is tilted, the lever 21
As described above, the time from when the paper 5 comes into contact with the paper 5 until it stops is extremely small, so it can be seen that it is determined by the arrangement accuracy of the paper braking device 2 without depending on the orientation of the paper. That is, it can be seen that the sheet posture can be easily and accurately held in the tray 1 stably without requiring a device such as a power source for pressing the sheet against the reference surface as in the conventional case.

In the specific embodiment shown in FIG. 1, a balancer 23 is provided to normally position the lever 21 downward.

A similar function can also be obtained by providing a fixed stop plate and making the lever 21 constantly abut against it using the force of a spring or the like.

〔Effect of the invention〕

According to the present invention, by utilizing the kinetic energy that enters the paper tray, when the paper collides with the paper braking device, the paper braking device can be easily rotated so as to be able to rotate immediately, and the rotation is prevented. It has a structure that can hold the paper and stop its movement, and multiple units are arranged perpendicular to the direction of paper movement, so there is no longer a need for a device that requires power to stabilize the paper's posture when the paper is stopped, as in the past. , it becomes possible to provide an inexpensive and highly reliable device.

[Brief explanation of drawings]

The figure is a schematic diagram showing an embodiment of a paper braking device according to the present invention. 1 is a helay, 2 is a paper braking device, 21 is a lever 22 is an arm, and 4 is a shaft. Knee/

Claims (1)

[Claims] In an electrophotographic printing device that prints on both sides of a cut paper, stops the cut paper in a tray after printing on one side, and discharges the cut paper to print on the front side again, the cut paper that enters the tray is A lever to be engaged and a lever having an angle substantially perpendicular to the lever are rotatably supported so that the equivalent mass at the engagement position is smaller than that of the cut paper, and a plurality of levers are arranged at right angles to the paper feeding direction. A paper braking device characterized by its deployment.