JPH0252248B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a document holding plate opening/closing device for a copying machine.

Conventionally, the hinge for the document holding plate of a copying machine has been either a general hinge with no balance characteristics or a single point balance torsion spring method, since the weight of the document holding plate is relatively light. , there was no such thing as getting any operating feel. Also, if the thickness of the original you are trying to copy changes,
It is extremely difficult to make the opening/closing operation feel the same at any given point as the document holding plate moves up and down.

This invention has been made in order to improve the problems of the conventional example described above, and as an opening/closing feeling of the original holding plate, it is balanced when opening and falls freely when closing to obtain pressing pressure of the original. In addition to the characteristics, even if the thickness of the original becomes thicker,
An object of the present invention is to provide a document holding plate opening/closing device for a copying machine configured so that the opening/closing feeling of a hinge can be maintained.

Therefore, the present invention includes a vertical case with an open top in which a compression coil spring is housed with its lower end supported, a hinge on the document holding plate mounting side that is rotatably attached to the upper part of the case, and An eccentric cam is attached to the rotation center of the hinge so as to rotate together with the hinge, with the cam surface in direct or indirect contact with the upper end, and an eccentric cam is provided on the copying machine body side, and the eccentric cam is attached to the center of rotation of the hinge, with the cam surface in direct or indirect contact with the upper end, and the eccentric cam is provided on the copying machine main body side, and the eccentric cam is attached to the center of rotation of the hinge, with the cam surface in direct or indirect contact with the upper end, and the eccentric cam is provided on the copying machine main body side, and the eccentric cam is attached to the center of rotation of the hinge so as to rotate together with the hinge, and the eccentric cam is installed on the main body side of the copying machine, and the eccentric cam is attached to the center of rotation of the hinge so that the cam surface is in direct or indirect contact with the upper end. It is characterized by comprising a guide means that supports the device so as to be movable up and down within the range.

Since the present invention is constructed in this way, even if the thickness of the document increases, the pivot mechanism of the document holding plate moves upward by the same thickness as the case, which reduces the biasing force of the compression coil spring against the cam. The opening/closing feeling for thin documents can be maintained without any change.

Further, in the present invention, when the document holding plate is closed, it is bent by being pressed by a compression coil spring by an eccentric cam that rotates following the closing operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the figure, the first
The figures show a side view of the opening/closing device according to the present invention, FIG. 2 shows a front view, and FIG. 3 shows a sectional view taken along the line AA in FIG. 1. Reference numeral 1 denotes a copying machine main body, and a rectangular guide rail 2 is fixed to the copying machine main body 1 with screws. A vertical case 4 with an open top, in which a plurality of guide rollers 3 are rotatably pivoted around shafts 3a, is mounted on the square-shaped guide rail 2 so as to be slidable upwardly and downwardly. The guide rail 2 is usually provided with weir plates at both its upper and lower ends, and the guide rail 2 is
The roller 3 is prevented from coming off from the roller 3, and the case 4 is thereby supported by the guide rail 2 so as to be able to move up and down within an appropriate stroke. As shown in the figure, a cylindrical pipe 5 is inserted into the case 4 and fixed to the case 4 together with a bottom plate 7 via a spring pin 6. A compression coil spring 8 is inserted into the pipe 5, and a slide plate 9 is inserted into the lower end of the compression coil spring 8 and is screwed into the bottom plate 7. The adjustment spring 10 allows the lower end position of the compression coil spring 8 to be adjusted up and down.

Further, a slide pin 11 is installed at the upper end of the compression coil spring 8 so as to be vertically slidable within the pipe 5.

On the other hand, on the top of the case 4, there is a document holding plate 1.
A rotary shaft 14 is rotatably supported on the mounting side hinge 13 of the case 2, and is rotatably supported on the case 4. Restrained eccentric cam 1
6 is fixed. In addition, in this embodiment, the rotating shaft 14 and the hinge 13 correspond to each other by a square shaft and a square hole.
The rotating shaft 14 and the eccentric cam 16 are connected to the spring pin 1
However, the cam shape is not limited to this embodiment, and the cam shape can be arbitrarily set based on the opening/closing moment of the document holding plate and the operating characteristics, as long as the same effect is achieved.

In this way, the eccentric cam 16 in this embodiment indirectly acts on the compression coil spring 8 via the slide pin 11, but the slide pin 11 is omitted and the cam surface of the eccentric cam 16 is directly applied to the compression coil spring 8. spring 8
It may be made to come into contact with.

The document presser plate opening/closing device configured as described above allows the document presser plate 12 to close when the document presser plate 12 is closed.
When the is rotated in the direction of arrow a, the eccentric cam 16 fixed to the rotating shaft 14 pushes the compression coil spring 8 through the slide pin 11, and applies a predetermined pressing force to the original placed on the top surface of the copying machine main body side 1. When opening the document holding plate 12, the document holding plate 12 is simply lifted by the tip thereof, and is lightly lifted by the repulsive force of the compression coil spring 8, and is balanced in the closed state shown in FIG. Also, when the document placed on the top surface of the copying machine main body 1 becomes thick, when the document presser plate 12 is closed and the tip is lightly pressed, the case 4 slides inside the square guide rail 2 by the guide roller 3 and rises. , the document holding plate 12 moves horizontally upward while remaining in the closed state in accordance with the thickness of the document, without changing the rotational torque characteristics of the hinge 13.

When the document holding plate 12 is opened from the above state, the case 4 gradually descends inside the rectangular guide rail 2 and returns to its original position due to the weight of the document holding plate 12, hinge 13, case 4, etc.

As described in detail above, the document holding plate opening/closing device for a copying machine according to the present invention has a simple structure, is easy to operate, can maintain a well-balanced operation feeling due to opening and closing, and can handle the thickness of the document. Even if the document pressure changes, the operation feeling of the document holding plate remains unchanged.

Further, the document holding plate can be opened and closed with a single touch regardless of the thickness of the document, and the operating characteristics can be arbitrarily set by adjusting the adjustment screw. Note that if a spring having nonlinear characteristics is used as the compression coil spring, it is possible to reduce the amount of eccentricity of the cam, and it is possible to achieve effects such as enabling a more compact design.

[Brief explanation of the drawing]

FIG. 1 is a side view of a switching device showing an embodiment of the present invention, FIG. 2 is a front view of FIG. 1, and FIG. 3 is a sectional view taken along the line A--A in FIG. 1. 2... Square-shaped guide rail, 3... Guide roller, 4... Case, 8... Compression coil spring, 9...
...Slide plate, 10...Adjustment spring, 11...Slide pin, 13...Hinge, 14...Rotation shaft, 1
6...Eccentric cam.

Claims (1)

[Scope of Claims] 1. A vertical case with an open top in which a compression coil spring is housed with its lower end supported, a document holding plate attachment side hinge rotatably attached to the upper part of the case, and the compression coil. An eccentric cam is attached to the rotation center of the hinge so as to rotate together with the hinge, with the cam surface in direct or indirect contact with the upper end of the spring, and an eccentric cam is provided on the copying machine main body side, and the eccentric cam is attached to the center of rotation of the hinge so as to rotate together with the hinge, and the cam surface is in direct or indirect contact with the upper end of the spring. 1. A document holding plate opening/closing device for a copying machine, comprising a guide means supporting the document so as to be movable up and down within a stroke. 2. The eccentric cam according to claim 1, wherein the eccentric cam is formed such that the amount of eccentricity of the cam surface that directly or indirectly contacts the compression coil spring increases as the document holding plate rotates in the closing direction. Copy machine document holding plate opening/closing device.