JPS6048843A - Sheet feeder - Google Patents

Abstract

PURPOSE:To prevent misfeeding such as multifeed, lost feeding and so on by applying elastic force to a push-up member according to each size of copy sheets stored in a sheet feed receptacle to suitably keep contact pressure of a copy sheet to a sheet feed roll. CONSTITUTION:A sheet feeder comprises a sheet feed receptacle 1 for storing copy sheets 4, a sheet feed roll 2 positioned above the receptacle 1 installed on a machine body and a push-up member 3 for pushing up the sheets 4 in the receptacle 1 from below to bring the uppermost sheet 4a into pressure contact with the roll 2. A push-up plate 8 of the member 3 is fixed to a rotatable shaft 7, and an arm 9 is fixed to the shaft 7. One end of a tension spring 10 is coupled to the forward end of the arm 9, and the other end of the spring 10 is coupled to one end of a rotor 11 rotatably mounted on the machine body. A side plate 5 of the receptacle 1 is provided with an engaging portion 6 for turning the rotor 11 to apply fixed tension to the spring 10 when the receptacle 1 is installed on the machine body.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to a copying machine, etc., in which a paper feed container containing stacked copy papers is set inside the machine, and the copy papers in the paper feed container are fed together. It relates to a paper feeding device that feeds sheets one by one.

[Prior art]

In the paper feed device of a copying machine, a paper feed container containing stacked copy paper is set in the paper feed device provided in the main body of the copy machine, and the copy paper in the paper feed container is pushed upward by a push-up member. Various types have been proposed in which copy sheets are raised and brought into pressure contact with a paper feed roll, and the copy sheets are sequentially fed into the machine from the topmost one by the rotational force of this paper feed container.

This type of paper feed device depends on the number of sheets of copy paper stacked in the paper feed container and the spring of the push-up member that pushes up the copy paper and presses the topmost copy paper against the paper feed roll. It is devised to balance the elastic force of the paper feed roll and the uppermost copy paper so that the pressure contact force between the paper feed roll and the topmost copy paper is always constant.

However, depending on the size of the copy paper stored in the paper feed container, the weight of the same number of copy paper can vary significantly, but as mentioned above, the paper feed is configured to provide a certain elastic force. The device cannot respond to changes in the weight of the copy paper, and it is difficult to keep the topmost copy paper in constant pressure contact with the paper feed roll, and if the paper size is small, As the weight becomes lighter, the pressure force becomes stronger and double feeding is more likely to occur.On the other hand, as paper size increases, the weight becomes heavier and the pressure force becomes weaker, making it more likely to cause blank feeding. There was a problem that mistakes were likely to occur.

[Purpose of the invention]

The present invention aims to solve the above-mentioned conventional problems. More specifically, the present invention provides a push-up member with an elastic force corresponding to each size of copy paper stored in a paper feed container,
It is an object of the present invention to provide a highly reliable paper feeding device that always maintains an appropriate pressure contact force for copy paper against a paper feeding roll and is free from feeding errors such as double feeding or blank feeding.

[Structure of the invention]

That is, the paper feeding device of the present invention includes a paper feeding container for storing copy paper, a paper feeding roll positioned above the paper feeding container set in the machine body to feed the copy paper, and a paper feeding roll provided on the machine body side. push up the copy paper in the paper feed container from the T side,
and a push-up member that presses the uppermost copy sheet against the paper feed roll, and the paper feed container has a side plate with a predetermined shape according to the size of the copy paper stored therein. On the other hand, the push-up member is provided with a shaft that can rotate on the body of the aircraft, and a push-up plate and an arm are attached to the shaft, and a push-up plate and an arm are attached to the push-up member. A tension spring for applying a predetermined tensile force is provided, one end of which is connected to the tip of the arm, and a rotatable body is provided on the body of the aircraft, one end of which is connected to the other end of the tension spring. When the paper feed container is set in the main body of the machine, the locking part of the paper feed container rotates the rotating body and stretches the tension spring, and the push-up plate is attached by the tension force of the tension spring. Applying rotational force to the shaft that is holding the paper, this pushes up the copy paper using the push-up plate and applies pressure between the topmost copy paper and the paper feed roll, creating a pressure that is commensurate with the size of the copy paper. It is designed to make the most of the

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A paper feeding device according to the present invention will be described below based on embodiments shown in the accompanying drawings.

1 and 2 show a paper feeding device of a copying machine according to the present invention, and this paper feeding device includes a paper feeding container (1), a paper feeding roll (
2) and push-up member (3), the above paper feed container +1
1 has a side plate so that an appropriate pressure is exerted between the uppermost side of the copy paper (4) and the paper feed roll (2) depending on the size of the copy paper (4) stored therein. A locking part (6) is provided at a predetermined position of (5),
The push-up member (3) also includes a shaft (7) rotatably provided on the main body of the copying machine, a push-up plate (8) attached to this shaft (7), and a push-up plate (8) attached to this shaft (7).
); a tension spring 00 having one end connected to the tip of the arm (9);
A rotary body 011 rotatably provided in the copying machine main body, and one end of which is connected to the other end of the tension spring opening σ.
It is composed of.

The rotating body θl) is pivotally supported by a support shaft aZ fixed to the main body of the copying machine, and a roller i13 that comes into contact with the locking part (6) of the paper feed container (1) is provided on the tip side of the rotating body. is provided, and when the paper feed container +11 is inserted into the machine, the roller 0 locks with the locking part (6) of the paper feed container (1) and the rotating body Q1
1 rotates, and a tensile shear spring (IG
extends and the arm (9) rotates, so the push-up plate (8
) rotates upward, so that the pressing force between the uppermost side of the copy paper (4) and the paper feed roll (2) is appropriately exerted depending on the size of the copy paper (4).

Note that the paper feed container (1) is provided with a separation claw 0◇ for separating the copy paper (4) one by one, but the means for separating the copy paper (4) is limited to this. For example, instead of this separating claw (141), when setting the paper supply container, a separating member is provided in front of the paper supply container with respect to the copy paper feeding direction, and this separates the copy paper sheets one by one. Of course, it is also possible to configure it in this way.

Therefore, if, for example, a B4 size original is to be printed at 1 copy, as shown in Figure 2, the entire copying machine body ( When inserted into the elm, this insertion action will cause
The rotating body 01 is attached to a predetermined position of the side plate (5) of the paper feed container (11), that is, from the front end (1a) of the paper feed container (11) to the locking portion (6) provided at the i!1 position. After the roller (Ie) comes into contact with the roller (Ie), the roller (Ie) is rotated counterclockwise around the support shaft ++s, and the tension spring (1G) is stretched by a predetermined amount, and a tensile force commensurate with this amount of extension is applied. spring 0
0 and causes the arm (9) to rotate fully clockwise, a predetermined push-up force is generated on the push-up plate (8) via the shaft (7) attached to the arm (9). Therefore, the push-up plate (8) to which a predetermined push-up force is applied by the tension spring 00 lifts the copy paper (4) completely upwards and presses it against the paper feed roll (2). Appropriate pressure contact force is generated between the uppermost top sheet (4a) and the paper feed roll (2).When the paper feed roll (2) rotates, this paper feed roll (2)
The top sheet (4a) that is pressed against the top sheet (4a) is sequentially conveyed into the machine, and is separated one by one by the separation claw 041 and fed reliably.

In addition, when attempting to copy a B5 size original, as shown in Fig. 3, a paper feed container H containing copy paper (171) of the same size is set in the machine and fed.
In this case, the copy paper (1η) stored in the paper supply container θΦ is half the weight of the B4 size copy paper (4) used for the previous copying process. Therefore, a predetermined pushing up force is applied to the pushing up plate (8), and even if the number of copies is the same, the weight of copy paper 0η is different from the previous one.
so that it comes into contact with the paper feed roll (2) with appropriate pressure.
The mounting position of the locking part 0υ on the side plate θω is located on the rear side compared to the B4 size one, that is, at a position away from the tip (t6a) of the paper feed container (+8). The tension spring Oe is stretched by a predetermined amount, and the tensile force by the stretched tension spring ilG applies a predetermined push-up force to the push-up plate (8), so that the tension spring Oe is stretched by a predetermined amount. Can exert pressure contact force,
This prevents feeding errors due to unbalanced pressure contact force.

In this way, on the side plate of the paper feed container, a tension spring is stretched by a predetermined length in order to apply a push-up force to the push-up plate corresponding to the weight of copy paper that varies depending on the size of the copy paper stored in the paper feed container. A locking plate is provided at a predetermined position, so that an appropriate pressing force can be exerted for copy paper of any size, and stable feeding of copy paper can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, a locking plate is provided at a predetermined position on the side plate depending on the size of the copy paper stored in the paper feed container. Even if the weight of the copy paper changes depending on the size of the copy paper (1-), the tension spring expands in response to this (1-) and applies a predetermined tensile force to the push-up plate, which causes the paper to come into pressure contact with the paper feed roll. Appropriate pressing force is exerted on the upper copy paper regardless of its size, and feeding errors such as double feeding or blank feeding can be prevented during paper feeding.

[Brief explanation of the drawing]

1 to 3 FIG. 1 shows a paper feeding device of a copying machine according to the present invention, FIG. 1 is a schematic perspective view thereof, and FIG.
FIG. 3 is a partially cutaway side view when a B4 size paper feed container is set into the machine. FIG. 3 is a partially cutaway side view when a B5 size paper feed container is set into the machine. 1.17...Paper feed container 2...Paper feed roll 3...
...... Push-up member 4... Copy paper (B4
Size) 5.19... Side plate 6.18... Locking part 8... Push-up plate 9... Arm 10...
......Tension spring 11...Rotating body 17
・・・・・・Copy paper (B5 size) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A paper feed container that stores copy paper, a paper feed roll located above the paper feed container set in the machine to feed the copy paper, and a paper feed roll provided on the machine to feed the copy paper in the paper feed container. In a paper feed device equipped with a push-up member that pushes up from below and presses the uppermost copy paper against the paper feed roll, the push-up plate of the push-up member is attached to a rotatable shaft, and the shaft Attach the arm to the
One end of a tension spring is connected to the tip of this arm, and the other end of the tension spring is connected to one end of a rotating body rotatably attached to the machine body. A paper feeding device comprising a locking portion that rotates the rotating body and applies a predetermined tensile force to the tension spring when the paper feeding container is mounted on a machine body.