JPH0211127B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a document pressure bonding plate for a copying machine or the like.

First, the configuration of a copying machine 1 to which the present invention is applied will be briefly described based on FIGS. 1 and 2. In the figure, reference numeral 2 denotes a document pressure plate, which is integrally molded with hinge parts 2a, 2b and a handle 2e from resin such as polypropylene, and is fixed to the main body of the copying machine at one end. In addition, reference numeral 3 denotes a document holding plate made of a material having cushioning properties such as Moltoprene (trade name), and a white sheet 4 is pasted on the surface thereof. 6 is a transparent material (glass) for placing the original, 7
8 is a rail that guides the slide of the document table including the glass 6; 8 is a plate that supports the rail 7; 9 is a plate that supports the rail 7;
is a rail that receives the glass 6.

Then, as shown in FIG. 3, the original pressure bonding plate 2 is bent at the hinge portion 2a and raised to the open position, and the solid portions 2a ₂ and 2a ₃ (see FIG. 4) of the hinge portion 2a are brought into contact with each other and the The state shown in Figure 3 is maintained. Similarly, in the hinge portion 2b, the solid portions come into contact with each other and the state shown in the figure is maintained. Therefore, by placing the original P to be copied on the glass 6, pulling down the original pressing plate 2, and pressing the original P, a prescribed copy can be made.

Therefore, as is already clear, since the opening and closing operations of the document pressure plate 2 of the copying machine are frequently performed, the hinge portions 2a and 2b are required to have strength, especially durability against repeated use.

However, the detailed structure of the conventional document pressure bonding plate 2 is as shown in FIG. 4, and it has a drawback in terms of durability against repeated use.

In other words, the conventional hinge portion 2a (the same applies to the hinge portion 2b) is formed into a U shape by a film-like flat bent portion 2a ₁ and a pair of solid portions 2a ₂ and 2a ₃ . However, as shown in the figure, the cross-sectional shape at any position (Fig. 5) is configured to be the same, so for example, when a force is applied in the direction of arrow A in the state shown in Fig. 3, the bending Part 2
This is because stress tends to concentrate on the joints a and b at the end faces of a ₁ and the solid parts 2a ₂ and 2a ₃ .

This will be explained based on FIGS. 6 and 7. As described above, when a force in the direction of arrow A is applied, a turning force about the contact point C acts on the solid portion _2a3 , and a tension force in the d direction acts on the bent portion _2a1 . If the force applied at this time acts as a uniformly distributed load over the entire area of the hinge part 2a, it will depend on the physical properties of the material that makes up the hinge part, and it will not be damaged by normal operation or some impact. . However, in reality, the applied force does not act equally on the hinge portion 2a, and since the handle portion 2e of the original pressure bonding plate 2 is provided at the left end as shown in FIG. The force A is often applied to a lopsided portion of the document pressure bonding plate 2. Furthermore, considering the configuration in which any position can be used as a handle, it is natural to think that an uneven load will act.
When an unbalanced load is applied, not only a simple tensile force (Fig. 6) acts on the bent portion _2a1 , but also a torsional force is generated, and this torsional force causes the bent portion 2a
There is a tearing force (shearing force) J at the joints a and b of a ₁ .
(FIG. 7; a schematic diagram of the hinge portion viewed in the longitudinal direction) is produced. Therefore, if there is even a slight flaw near the joints a and b, stress concentration will occur in that part and the joint will tear, and even if there is no flaw, the joint between the bent part 2a ₁ and the solid parts 2a ₂ and 2a ₃ will break. The rapid change in the molding condition causes whitening, etc., which weakens the material to a certain extent and makes it more likely to become a starting point for tearing.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a document pressure bonding plate having a bent portion with high tear strength.

The structure of the present invention that achieves the above object is as follows: an openable/closable document pressure bonding plate that presses a document onto a document mounting table; a flexible bent portion for making the document pressure bonded plate openable and closable; a pair of solid parts formed opposite to each other with the original pressing plate in between, and when the original pressing plate is opened to a predetermined open position, the solid parts come into contact with each other to regulate the opening angle of the original pressing plate; The document pressure bonding plate is characterized in that the vicinity of the end of the bent portion has extra slack relative to other portions.

The present invention will be explained below based on the illustrated embodiments.

First, FIG. 8 shows the document pressure bonding plate 22 of the first embodiment.
FIG _. 9 is a side view in the direction of arrow E in FIG _. 22a ₃ , and a bent portion 22a ₄ that is slack in the shape of a bridge, which is an extension of the bent portion 22a ₁ . According to the characteristics of this embodiment,
As shown in FIG. 9, the unfolded length (l+α) of the bent portion 22a ₄ is configured to be longer than the length l of the bent portion 22a ₁ . Therefore, even if the tension d as shown in FIG. 6 acts on the bent portion _22a1 ,
Since the bent portion _22a4 is slack, the tension d does not act on it. As a result, no tearing force acts on the joints a and b of the bent portion _22a4 .

10 and 11 each show a modification of the one shown in FIG. 8, and FIG.
In place of _2a4 , the bent portion _32a4 is sagging in a wavy shape, and in FIG. 11, the bent portion _42a4 is sagging in a conical shape.

FIG. 12 is a perspective view of the main parts _of the document pressure bonding plate 52 of the second embodiment.
a ₄ -1 are the solid parts 52a ₂ and 52a ₃ of the original pressure bonding plate.
It is characterized by being more concave than the end faces 52a ₂ -1 and 52a ₃ -1. This feature is based on the original pressure bonding plate 5.
This is effective when the outer circumference of No. 2 is thick. In other words, even if the bridge-like slack is insufficient and a tensile force is applied, there will be no bends in areas where the wall is thick (long in the vertical direction) and has high rigidity. , tearing force does not act on the joints a and b of the bent portion. On the other hand, the wall thickness (long in the lateral direction) of the solid portion at the position opposite to the end surface 52a _{4 -1} of the bent portion 52a 4 in the figure is thin and the solid portion is easily bent, so the tension acting on the bent portion 52a ₄ is correspondingly large. do not have. Therefore, no tearing force acts on the joints a and b.

Note that instead of the bridge-like slack, a wave-like slack as shown in FIG. 10 or a conical slack as shown in FIG. 11 may be used.

FIG. 13 is a perspective view of the third embodiment;
In addition to the features of the illustrated embodiment, a feature lies in the formation of inclined solid portions 62a ₅ and 62a ₆ near the ends in the width direction. In other words, the solid portion 6
2a ₅ and 62a ₆ are shaved by an angle θ compared to the solid portions 62a ₂ and 62a ₃ .

Therefore _, when a force is applied in the direction of arrow A while the original pressure bonding plate is in an upright state as shown in _FIG .
A tensile force d as shown in FIG. 6 acts on _a1 , but does not act on the bent portion _62a4 . In other words, the solid portions 62a ₅ and 62a ₆ do not come into contact with each other, and therefore no moment about point C acts on them.

FIG. 14 is a perspective view of the fourth embodiment.
In addition to the features _of the embodiment shown in _{FIG .}
It has the characteristic that it is more concave than the end faces 72a ₂ -1 and 72a ₃ -1 of 72a ₃ . Note that the effect of this feature is the same as the effect shown in FIG. 12 described above, so a description thereof will be omitted.

15, 16, and 17 show a modification of FIG. 14, and FIG. 15 shows a bent portion 82a ₄ that is sagging in a wavy shape instead of the bent portion 72a ₄ that is sagging in a bridge shape. FIG. 16 shows the end face 92a ₄ -1 of the bridge-shaped slack bent portion 92a ₄ formed into an arc shape with radius r, and FIG. 17 shows the bridge-shaped slack bent portion 92a ₄ in FIG. Bending portion 102
A ₄ is formed into a conical shape.

Note that by forming the end face of the bent portion into an arc shape, there is an effect that concentration of stress can be avoided.
Therefore, this can also be applied to the embodiments shown in FIGS. 8 and 10 to 13.

FIG. 18 shows another modification in which the solid part and the bent part are connected by a circular arc, which has the effect of avoiding stress concentration.

The above is a description of the embodiment of the document pressure bonding plate according to the present invention, but it goes without saying that the present invention is not limited to this embodiment.

For example, as a means of creating extra slack,
Anything that connects the opposing solid parts with the shortest distance plus α may be used.

As explained above, in the present invention, concentration of stress at the end of the bent portion can be avoided and the durability of the bent portion can be improved.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the copying machine, Fig. 2 is a longitudinal sectional view of the main parts of Fig. 1, Fig. 3 is a longitudinal sectional view showing the state after operation of Fig. 2, and Fig. 4 is a conventional example. A perspective view of a document pressure bonding plate having a bent portion, FIG.
6 is a sectional view of the hinge portion in the open state of the original pressure bonding plate; FIG. 7 is a schematic diagram showing the state of the hinge portion when torsional force is applied;
FIG. 8 is a perspective view of an embodiment of the document pressure bonding plate according to the present invention, FIG. 9 is a side view in the direction of arrow E in FIG. 8, and FIGS. 10 and 11 are modifications of FIG. 8. A perspective view showing an example, FIG. 12 is a perspective view of a second embodiment of the document pressure plate according to the present invention, FIG. 13 is a perspective view of the third embodiment, and FIG. 14 is a perspective view of the fourth embodiment. FIG. 15 to FIG. 17 are perspective views each showing a modification of FIG. 14, and FIG. 18 is a sectional view showing another modification. 22a, 52a...hinge portion, 22a ₁ , 52
a ₁ , 62a ₁ , 72a ₁ ...Bending part (center part), 2
2a ₂ , 22a ₃ , 52a ₂ , 52a ₃ , 62a ₂ , 62
a ₃ , 72a ₂ , 72a ₃ ... solid part, 22a ₄ , 5
2a ₄ , 62a ₄ , 72a ₄ ...Bending part (sagging part),
62a ₅ , 62a ₆ , 72a ₅ , 72a ₆ ... solid part (near the end), 52a ₄ -1, 72a _{4 -1} , 92a ₄ -
1...End face, a, b...Joint part.

Claims (1)

[Scope of Claims] 1. An openable and closable document pressure bonding plate that presses a document onto a document mounting table, comprising: a flexible bent portion for making the document pressure bonded plate openable and closable; a pair of solid portions formed opposite to each other, and when the original pressure bonding plate is opened to a predetermined open position, the solid portions come into contact with each other to regulate the opening angle of the document pressure bonding plate; A document pressure bonding plate characterized in that the vicinity of the end portion has an extra slack with respect to the other portion of the bent portion. 2. The document pressure bonding plate according to claim 1, wherein there is no bent portion near the end of the solid portion.