JP3666657B2 - Sheet material supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material supply apparatus for a copying machine, a printer, a facsimile machine, etc., and to a sheet material supply apparatus having a spring settling prevention mechanism used for the sheet material supply apparatus.
[0002]
[Prior art]
In general, an image forming apparatus such as a copying machine, a printer, a facsimile, or the like supplies a sheet material such as a recording sheet or a document set on a sheet feeding cassette, a manual sheet feeding tray, or a document tray to an image forming unit or an image reading unit. A sheet material supplying device (hereinafter referred to as a paper feeding device) is provided.
FIG. 4 is a schematic diagram showing a cross section of a conventional paper feeding device Z. The conventional paper feeding device Z is separated from the paper feeding roller 1 by a cylindrical paper feeding roller 1 having a layer made of rubber or the like formed on its peripheral surface and rotatably supported on a predetermined shaft 3a. And a lift plate 3 provided so as to be able to come into contact, and a sheet material placed on the lift plate 3 is elastically biased against the paper feed roller 1 by an elastic member such as a coil spring 3b (or a helical spring). When the sheet feeding roller 1 rotates, only the uppermost sheet material in contact with the sheet feeding roller 1 is separated by the friction pad 4 elastically urged by the sheet feeding roller 1 by the coil spring 4b. Supplied toward the forming section and the like. The lift plate 3 is provided on the sheet feed roller 1 side of the sheet feed tray 2 on which the sheet material is placed (the leading side in the conveyance direction of the placed sheet material).
Here, every time one sheet material is supplied, the lift plate 3 is once separated from the paper feed roller by the action of a cam (not shown) provided on the rotating shaft 1a of the paper feed roller 1 (FIG. 4). ), The uppermost surface of the sheet material is urged toward the paper feed roller 1 when it is moved again to the side close to the paper feed roller 1 side (position shown by the solid line in FIG. 4). Thus, when the lift plate 3 is away from the paper feed roller 1, the sheet material is not biased by the paper feed roller 1, so the paper feed roller 1 is idled and the sheet material is not sent out. Only when the lift plate 3 comes close to the paper feed roller 1, the sheet material urged by the paper feed roller 1 is sent out by the rotation of the paper feed roller 1.
[0003]
[Problems to be solved by the invention]
However, if the lift plate 3 is pressed by an excessive force by the user when assembling the paper feeding device or removing a paper jam, the coil spring 3b and the like release the range of elastic deformation, that is, the presser. In other words, there is a problem that deformation (compression or expansion) occurs beyond the range of deformation that returns to the original shape (position), causing so-called spring settling. As a result, the force for urging the sheet material against the sheet feeding roller 1 by the lift plate 3 is weakened, and there is a problem that the subsequent sheet material supply is not normally performed. In particular, a manual paper feeding device for originals and recording paper in a copying machine or printer is provided in a state exposed to the outside of the main body of the copying machine or the like, so that the operation of pressing the lift plate 3 as described above is easily performed. ， Spring was prone to occur.
Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is that excessive force is applied to the lift plate of the sheet feeding device, and the spring that biases the lift plate is distorted. Is to prevent.
[0004]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a rotating paper feed roller, a lift plate provided so as to be detachable from the paper feed roller, and an elastic biasing of the sheet material on the lift plate to the paper feed roller. in the supply device of the sheet material comprising a coil spring which, deformation range of the coil spring so that the range of elastic deformation of the coil spring, extending in a direction parallel to the stretching direction of the coil spring at one end of the coil spring A sheet material supply apparatus including a regulating portion.
As a result, even when the lift plate is pressed by a user or the like, the coil spring is deformed only within the range of elastic deformation, so that the coil spring is not set.
Moreover, it is preferable that the free end of a control part forms a bending part.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a schematic sectional view of a sheet feeding device X according to an embodiment of the present invention, FIG. 2 is an enlarged view of a coil spring, and FIG. 3 is an enlarged view of a leaf spring.
Hereinafter, the sheet feeding device X according to the embodiment of the present invention will be described with reference to FIG. The same parts as those of the conventional paper feeding device Z shown in FIG. 4 will be described using the same numbers and the same names.
The paper feeding device X is connected to and separated from the paper feeding roller 1 by a cylindrical paper feeding roller 1 having a layer made of rubber or the like formed on its peripheral surface, and rotatably supported on a predetermined shaft 3a. A lift plate 3 is provided, and a sheet material placed on the lift plate 3 is elastically biased to the paper feed roller 1 by an elastic member such as a coil spring 30 (or a helical spring). As the paper feed roller 1 rotates, only the uppermost sheet material in contact with the paper feed roller 1 is made of a friction pad made of foaming rubber or the like that is elastically biased to the paper feed roller 1 by a coil spring 4b. 4 is supplied to an image forming unit or the like included in a printer or the like on which the paper feeding device X is mounted. The lift plate 3 is provided on the sheet feed roller 1 side of the sheet feed tray 2 on which the sheet material is placed (the leading side in the conveyance direction of the placed sheet material).
Here, the lift plate 3 is once separated from the paper feed roller by the action of a cam (not shown) provided on the rotating shaft 1a of the paper feed roller 1 every time one sheet material is supplied (see FIG. 1). After the position indicated by the broken line, the sheet is moved again to the side close to the sheet feed roller 1 (the position indicated by the solid line in FIG. 1) to urge the uppermost surface of the sheet material to the sheet feed roller 1. Thus, when the lift plate 3 is away from the paper feed roller 1, the sheet material is not biased by the paper feed roller 1, so the paper feed roller 1 is idled and the sheet material is not sent out. Only when the lift plate 3 comes close to the paper feed roller 1, the sheet material urged by the paper feed roller 1 is sent out by the rotation of the paper feed roller 1. That is, each time the paper feed roller 1 rotates, one sheet material is sent out. Then, the next transport roller (not shown) is provided at a position closer than the distance transported by one rotation of the paper feed roller 1, and the sheet material is transported sequentially. The rotation of the paper feed roller 1 is controlled by a control command from a printer or the like on which the paper feed device X is mounted.
[0006]
Referring to FIG. 2, the coil spring 30 is further provided with a restricting portion 31 that hangs downward from the upper end portion, and a bent portion 32 is formed at the free end of the restricting portion 31. The restricting portion 31 prevents the coil spring 30 biasing the lift plate 3 from being deformed (compressed) beyond the elastic deformation range even when the user presses the lift plate 3 with an excessive force, for example. Therefore, when the bent portion 32 formed at the free end of the restricting portion 31 comes into contact with a fixed portion such as the main body base, the coil spring 30 is not further compressed, so that so-called sag occurs. Can be prevented. As described above, since the bent portion 32 is formed in this embodiment, even if the bent portion 32 contacts the fixed portion, the fixed portion is not damaged and stable regulation is possible. The present invention can be implemented without forming the portion 32. The restricting portion 31 may be erected upward from the lower end portion of the coil spring 30.
[0008]
【The invention's effect】
As described above, according to the present invention, a very simple configuration prevents the coil spring that urges the lift plate from being deformed beyond its elastic deformation range even when a user or the like presses the lift plate. As a result, it is possible to prevent so-called sag in the coil spring .
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a paper feeding device X showing an embodiment of the present invention.
FIG. 2 is an enlarged view of a coil spring.
FIG. 3 is an enlarged view of a leaf spring.
FIG. 4 is a schematic sectional view of a conventional paper feeding device Z.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Paper feed roller 1a ... Feed roller rotating shaft 2 ... Manual feed tray 3 ... Lift plate 3a ... Shaft 4 ... Friction pad 30 ... Coil spring (elastic member)
31 ... Restriction part 32 ... Bending part 40 ... Leaf spring (elastic member)
41 ... Restriction part 42 ... Bending part

Claims (2)

A sheet material supply device comprising: a rotating sheet feeding roller; a lift plate provided so as to be detachable from the sheet feeding roller; and a coil spring that elastically biases the sheet material on the lift plate to the sheet feeding roller. In
As deformation range of the coil spring is in the range of elastic deformation of the coil spring, the sheet material, characterized in that a restricting portion extending in a direction parallel to the stretching direction of the coil spring at one end of the coil spring Feeding device. The sheet material supply apparatus according to claim 1 , wherein a bent portion is formed at a free end of the restricting portion.

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