JPS6017733B2 - Paper cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feed cassette for copying machines, printing machines, etc.

Sheet paper for copying machines, etc. (e.g. transfer paper, photosensitive paper, etc.)
As a replacement method, sheet paper of different sizes and types of paper is stored in cassettes in advance, and the cassette containing the required sheet paper is loaded into the cassette holder of a copying machine, etc., and the sheet is removed. A so-called cassette-type paper feeding system in which paper is fed into the copying machine by a sheet feeding roller provided in the main body of the copying machine is convenient for sheet paper replacement operations and is widely adopted.

FIG. 1 shows a typical example of a conventional cassette used in the above-mentioned cassette type paper feeding method.

Inside the box-shaped main body 1, there is provided an intermediate plate 3 whose one end A is swingably supported and whose other end is held in the upward direction by a spring 2.

Then, sheets of paper P are stacked on the stacking surface 3a of this intermediate plate 3. Therefore, the middle plate 3 is pushed up to the stereotactic pupil by the spring 2, and when the cassette is loaded into the copying machine main body, the sheet paper P is pushed down by a certain amount by the feeding loaf R provided in the copying machine main body, that is, moderately It contacts the feed roller R with a pressing force. When the feed roller R rotates in response to a paper feed signal, the uppermost sheet of paper stacked on the intermediate plate 3 is sent out into the copying machine by the frictional force of the feed roller R. Note that 4 is a separating claw provided at both corners of the leading end of the feeding side, which temporarily prevents the advance of the sheet paper P, and feeds the sheet paper one by one using the rotational frictional force of the roller R and the stiffness of the sheet paper. It is. In addition, the spring 2 is connected to the sheet paper P loaded in the box-shaped main body 1.
The pressure between the sheet paper P and the roller R is always constant regardless of the number of sheets loaded. It is said that However, the conventional cassette described above has the following problems. in general,
The box-shaped main body 1 of the cassette is made of plastic because of its ease of molding and relatively low specific gravity, and the mold is very expensive. Therefore, usually, a box-shaped main body of one size is used, that is, one type of mold is used, and only the parts attached to the inside (for example, the middle plate 3, etc.) are changed, so that sheet paper of several different sizes can be loaded. things are being done. In that case, if you try to load sheets that are shorter than the length of the cassette case (in the sheet feeding direction), the problem arises that the number of sheets that can be stacked will decrease. and second
This will be explained with a diagram. In order to stack sheets of paper on the stacking surface 3a of the middle plate 3, a back support part 3 corresponding to the length of the sheet paper P is required on the middle plate 3 in order to regulate the position of the rear end of the sheet paper. . Now, suppose that a sheet of paper that is shorter than the length of the cassette box-shaped body 1 is P, and a middle plate corresponding to the sheet of paper P is called 3b.
The back rest portion is designated as 32. If the fulcrum of the middle plate 3b is set at point A, which is approximately at the rear end of the box-shaped body of the same machine as in Figure 1, the distance of the backrest 32 from point A will be greater than in the case of Figure 1. , the amount of vertical movement of the back rest due to the vertical movement of the middle plate 3b also becomes large. This vertical movement is caused by the cassette box-shaped body 1
It must be carried out in a space limited to the darkness between the lid 5 and the lid 5, and the dimensions of the backrest 32,
must be made smaller. If the dimension of the backrest portion 32 is smaller than the dimension, that is, the number of sheets that can be loaded is reduced. Therefore, as a countermeasure to this problem, it is conceivable to move the fulcrum of the middle plate 3b from the point A to the vicinity A' of the back rest part 32, as shown in FIG.

By doing so, the vertical movement range of the backrest 32 is reduced, the dimensions can be increased, and the number of sheets that can be loaded can be increased. However, in this case, the fulcrum and the tip 3 of the middle plate 3b
Since the distance from the middle plate 3b becomes small, the swing angle of the middle plate 3b becomes large. In this case, depending on the number of stacked sheets P, the contact angle between the sheet P and the separating claw 4 and the amount of contact vary considerably, which becomes a major obstacle to stable paper feeding. In particular, the change in the swing angle of the middle plate 3b caused by moving this fulcrum forward becomes larger as the number of sheets loaded in the cassette increases, increasing the instability of paper feeding.

Therefore, the present invention solves the above problems, allows the cassette box-shaped main body to be commonly used for various sheet paper sizes with a simple configuration, and provides stable paper feeding performance even when the number of sheets loaded is large. The purpose is to provide a cassette with

That is, the present invention that achieves the above object includes a box-shaped main body, a stacking surface having a length corresponding to the size of the sheets to be stacked, and a spine that regulates the position of the trailing edge of the sheet paper for stacking the sheets on the stacking surface. It is swingably supported by the box-shaped main body with an abutment part,
The middle plate is cut out so as not to interfere with the fixed backrest, and the box-shaped main body is provided at a distance corresponding to the sheet paper size from the tip of the loading surface, and cooperates with the backrest of the middle plate. and a fixed backing material for regulating the position of the trailing edge of the sheet. That is, the present invention
The position of the trailing edge of the sheets stacked on the loading surface is regulated by the cooperation of the back rest provided on the swinging middle plate and the fixed back rest that does not swing fixed to the cassette box-shaped body. It is something. An embodiment of the present invention will be described below with reference to FIGS. 4, 9, 5, 6, and 7. The cassette of this embodiment has sheet paper P loaded on the loading surface 6 of the middle plate 6.
, a fixed back rest 8 is provided on the bottom surface of the cassette box-shaped main body in addition to the back rest part 7 of the middle plate 6 to provide a back rest for regulating the rear end position of the cassette.

This fixed backrest 8 extends from the front end 1 of the sheet paper stack.
That is, it is erected at a position approximately equal to the size of the sheet P from the tip of the paper feeding side of the loading surface 6, parallel to the front end 11, that is, perpendicular to the bottom surface of the box-shaped main body. The height of the fixed backrest 8 extends to the vicinity of the lid 5 of the cassette, as shown in FIG. Further, as shown in FIG. 7, the loading surface 6 and the backrest 7 of the middle plate 6 are partially cut out and arranged so as not to interfere with the middle plate 6 in the width direction. By newly providing the fixed back support 8 as described above, the middle plate 6 is supported using the approximately rear end point A of the box-shaped main body 1 as a fulcrum in the same manner as before, and the back support part 7 supports the sheet paper P. Although it is located at almost the same position as the fixed backrest 8 when fully loaded (Fig. 5) and at a height that does not interfere with the lid 5 even when no sheet paper is loaded (Fig. 6). Regardless of the height of the backrest part 7 of the middle plate 6, sheets P can be stacked to the full depth of the box-shaped main body 1.

That is, since the height of the backrest part 7 of the middle plate 6 is not restricted, the fulcrum of the middle plate 6 can be set at the point A farthest from the tip 63, and the swing of the middle plate 6 is prevented. Since the angle can be minimized, there is little change in the relationship between the sheet paper and the separation claw 4, and stable paper feeding can be performed.・
Moreover, since the back support part 7 is provided on the middle plate 6, it is guaranteed that the separation claws 4 will be engaged with all the sheets up to the last stacked sheet.

The reason for this will be explained below with reference to FIG. First, the fixed backrest part 8
Assume that the middle plate 9 without a backrest part is used in combination. When this is fully loaded with sheet paper, the uppermost sheet paper is positioned by the fixed back support 8 whose dimensions are set for the sheet paper, so there is no problem in getting it onto the separation claw 4. do not have. However, when the number of stacked sheets decreases, the middle plate 9 becomes cumbersome, so the distance between the separation claw 4 and the fixed backrest 8 becomes larger than the size of the sheet, and the difference between The position of the sheet paper becomes unstable by the amount of time (evening, overnight), and it is no longer possible to guarantee that the paper sheet will be attached to the separating claw 4. In contrast, if there is a back rest part on the middle plate as in this embodiment (Fig. 6), when the number of stacked sheets decreases, the rear end of the sheet paper will not be attached to the fixed back rest 8. , is positioned at a distance from the separation claw 4 by the back support portion 7 of the intermediate plate 6, so that the amount of application to the separation claw 4 is always guaranteed, and stable paper feeding can be performed.

Therefore, in this embodiment, when the number of stacked sheets is large, the rear edge position of the stacked sheets is mainly regulated by the fixed backrest 8, and when the number of stacked sheets decreases, the backing member 7 provided on the middle plate 6 is used. In other words, the back end position of the stacked sheets is regulated by the cooperation of the back support member 7 and the fixed back support member 8.

In this embodiment, a cassette with a structure in which the middle plate is pushed up by the spring 2 has been described, but the present invention is not limited to this, and a structure in which a lever from the main body enters into the cassette and pushes up the middle plate is explained. Of course, the present invention can be applied to general cassettes in which the middle plate swings according to the number of sheets loaded.

As described above, although the cassette of the present invention achieves a reduction in cassette manufacturing costs by commonly using the cassette box-shaped main body for sheet paper of various sizes, it is not affected by the size of the sheet paper. Even if the number of sheets loaded is large, it has stable paper feeding performance up to the last sheet.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional cassette; FIGS. 2 and 3 are sectional views for explaining the problems of the subordinate cassette; FIGS. FIG. 7 is a sectional view showing one embodiment, FIG. 7 is a perspective view thereof, and FIG. 8 is a sectional view for explaining the effects of this embodiment.・…
Spring, 3...middle plate, 3,,32...backrest, 3a...loading surface, 3b...middle plate, 5...cassette lid, 6...・Middle plate, 6,...Loading surface, 7・
...Back rest part, 8...Fixed back rest. No-hair figure 3 Atsushi figure Murasaki 4 figure Hata figure Acceptable side hair 7 figure 8

Claims (1)

[Claims] 1. A box-shaped main body, a stacking surface having a length corresponding to the dimensions of the sheets to be stacked, and a backrest portion for regulating the position of the trailing edge of the sheet paper for stacking the sheets on the stacking surface. and is swingably supported by a box-shaped main body.
A middle plate is cut out to avoid interference with the fixed backrest, and a box-shaped main body is provided at a distance according to the size of the sheet paper from the tip of the loading surface, and cooperates with the backrest of the middle plate. A paper feed cassette comprising: a fixed spine member that regulates the rear end position of the sheet paper;