JPS6135093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feeding cassette for feeding sheets one by one from a cassette containing a stack of sheet-like recording paper used in, for example, an electrophotographic apparatus or a printing machine.

2. Description of the Related Art In electrophotographic devices and printing machines, sheet feeding devices are widely used in which a large number of sheets such as recording paper are set in advance and the sheets are automatically fed one by one. There are two methods for setting a large number of sheets: one is to set the sheets directly into the main body of the sheet feeding device, and the other is to place the sheets in a cassette that can be removed from the sheet feeding device and set the sheets by loading this cassette. The latter has the advantage of being particularly easy to operate. This kind of paper feed cassette is, for example,
As described in Publication No. 39251 and Japanese Unexamined Patent Publication No. 131139/1980, the upper part of the cassette body is opened to load sheets in all cassettes, but this loading work is extremely difficult. In particular, the former type of cassette has the disadvantage that the number of sheets that can be set at one time cannot be increased because the paper feeding position (level) changes with the number of remaining sheets. In the latter cassette, a sheet receiving plate which is elastically biased upward is provided within the cassette body, but the sheet must be loaded against this elastic force, making the loading operation difficult. In addition, such cassettes are equipped with separation claws to separate the sheets one by one, but if the structure is such that the separation claws cannot be easily released, the sheets must be loaded by climbing over the separation claws. In addition, the leading edge of the sheet is likely to be deformed, resulting in poor separation, which may result in two sheets being fed at the same time or a jam. Further, even with a structure in which the separating claws can be easily released, after the sheet is loaded, it is necessary to return the separating claws to the upper position while pressing the sheet downward, making the sheet loading operation troublesome.

In order to eliminate these drawbacks of conventional paper feed cassettes, the applicant opened the bottom of the cassette body, installed a sheet receiving plate there that could be opened and closed, and installed the sheet receiving plate with the cassette upside down. open up,
This led to the development of a paper feed cassette that allowed sheets to be loaded into the cassette body (Japanese Patent Application Laid-open No. 1983-
(See No. 16821). Although such a paper feeding cassette is very effective in loading sheets, an elastic member for pressing the sheets against the separation claw is provided not on the cassette side but on the sheet feeding device main body side.
In this case, the elastic member must be in a retracted position when the cassette is inserted into the sheet feeding device, and then in the active position after the cassette is inserted to push up the sheet receiving plate from below. It has been found that this has the disadvantage that the drive mechanism for the elastic member is considerably complicated.

The object of the present invention is to provide a paper feed cassette, as previously developed by the applicant, which is provided with an openable sheet receiving plate on the lower surface of the cassette main body, and which allows sheets to be loaded into the cassette by turning the cassette upside down. For example, in a paper feed cassette, an elastic member is provided on the sheet receiving plate or the cassette body to press the sheets in the cassette against the separating claws, and by loading the sheet receiving plate so as to cover the bottom surface of the cassette body, the sheets can be pressed against the separating claws. It is an object of the present invention to provide a paper feed cassette which can be pressed against the paper feed cassette.

The paper feed cassette of the present invention can store a large number of stacked sheets, and has a window on a part of the top surface through which the means for discharging the sheets one by one acts on the topmost sheet. a box-shaped cassette main body with an open bottom surface; a sheet receiving plate having a size that covers almost the entire open bottom surface and attached to the cassette main body so as to be able to move slightly into the cassette main body; A separating claw is provided near the window and has the function of separating sheets one by one, and after the cassette main body is turned over, the sheet receiving plate can be moved from the bottom surface to load the sheets into the cassette main body. Further, with the sheet receiving plate positioned so as to close the open lower surface of the cassette main body, an elastic member that acts between the cassette main body and the sheet and presses the sheet against the separating claw is attached to the sheet receiving plate or It is characterized by being provided in the cassette body.

According to the paper feed cassette of the present invention, sheets can be loaded into the cassette main body with the cassette turned over and the sheet receiving plate removed.
The sheet loading operation is extremely simple, and since an elastic member is provided that presses the sheet against the separating claw while the sheet receiving plate is positioned on the open lower surface of the cassette body, the configuration of this elastic member is simple, and the sheet feeding device There is no need to provide any elastic member on the side.

The present invention will be described in detail below with reference to the drawings.

1 to 3 show the construction of an embodiment of the paper feed cassette of the present invention. FIG. 1 shows a sheet feeding cassette, generally designated by the reference numeral 1, mounted on a sheet feeding device serving as a means for discharging sheets one by one. The sheet feeding device includes a paper feeding roller 2, which is rotated in the direction of the hour hand indicated by the arrow and supported by a swinging arm 3, so as to move the roller 2 toward and away from the cassette 1. The cassette 1 comprises an integrally molded cassette body 4, for example of plastic. The cassette main body 4 is approximately box-shaped, and has a window 5 formed on its upper surface 4A through which the paper feed roller 2 can be inserted and removed, and its lower surface is open. This open lower surface can be substantially covered by a seat receiving plate 7 rotatably mounted around a shaft 6. A sheet 8 is placed on the sheet receiving plate 7, and this sheet is positioned by the side wall of the cassette body 4, the front wall 4B, and the end stopper 4C. As clearly shown in FIG. 2, the seat receiving plate 7 is formed with an opening 9 into which the end stopper 4C is inserted. In order to separate the sheets 8 loaded into the cassette main body 4 one by one from the topmost sheet and feed them, the cassette main body 4
Separation claws 10A and 10B are provided at the upper end of the front wall. In this example, these separation claws are fixed.

FIG. 2 shows the state in which the cassette 1 is removed from the sheet feeding device and turned over in order to load sheets into the cassette 1. A leaf spring 11 as an elastic member is installed approximately in the center of the outer surface of the seat receiving plate 7.
One end of the tube is secured with a rivet or the like as clearly shown in FIG. In other words, part 7 of the sheet receiving plate 7
A is made to protrude outward, and one end of the leaf spring 11 is fixed to this protrusion. At this time, the leaf spring 11 is brought into pressure contact with the seat receiving plate 7 at position 12. The leaf spring 11 extends forward along the outer surface of the seat receiving plate 7, and a handle 13 is attached to its tip. A recess is formed in the handle 13, and a hook 14 is mounted in the recess so as to be rotatable about a shaft 15. As shown in FIG. 1, a compression spring 16 is inserted between the hook 14 and the leaf spring 7.
is rotated in the direction of the hour hand in the plane shown in FIG. This rotation is restricted by the bottom 14A of the hook 14 coming into contact with the leaf spring 7. The tip 14B of the hook 14 protrudes into a locking recess 17 formed on the inner surface of the front wall of the cassette body 4 and engages with the side wall thereof. Therefore, in the state shown in FIGS. 1 and 2, the hook 14 is engaged with the locking recess 17 of the cassette body 4, and the sheet receiving plate 7 is held inside the cassette body 4 by the elastic force of the leaf spring 11. This causes the sheet 8 to
are pressed against the separation claws 10A and 10B. As the number of sheets in the cassette decreases, the sheet receiving plate 7 rotates inward of the cassette, and the sheets are separated by the separating claws 10A and 10B until the last sheet.
Can be pressure-welded to.

Figure 3 shows a state in which the sheet receiving plate 7 is opened from the bottom surface of the cassette body 4 (in Figure 3, the cassette is turned upside down, so it is the top surface) in order to load the sheets 8 into the cassette body 4. shows. In order to release the sheet receiving plate 7, the rear end 14C of the hook 14 is pushed down inward of the cassette body 4, and the tip 14B of the hook 14 is released from the locking recess 17 formed in the front wall 4B. . After loading the sheets 8, the sheet receiving plate 7 is positioned so as to close the opening of the cassette body 4, and the handle 13 is pushed down to engage the tip of the hook 14 with the locking recess 17.

As described above, according to the paper feed cassette of the present invention, the sheets 8 are loaded into the cassette main body 4 and the sheets 8 are loaded into the cassette main body 4, and the sheet receiving plate 7 is arranged to close the opening on the lower surface of the cassette main body 4. Separation claw 10A,
10B. Therefore, it is not necessary to provide the sheet feeding device with a mechanism for pressing the sheet receiving plate inward, and the structure becomes simple. Further, in the above-described example, the handle 13 attached to the leaf spring 11 also functions as a handle when opening and closing the seat receiving plate 7, so there is no need to provide a separate handle. In addition, since the handle 13 wraps around the sharp edges of the leaf spring 11, there is no risk of the user being injured by the edges, and the rigidity of this part of the leaf spring 11 can be increased, so that the seat The elastic pressing force against the receiving plate 7 also increases.

4 to 6 show the constructions of some other examples of paper feed cassettes according to the present invention. Since these examples differ from the previous example only in the locking means of the leaf spring, the same parts are shown with reference numerals.

In the example shown in FIG. 4, the hook 20 is pivotally attached to the front wall 4B of the cassette body so as to be rotatable about a shaft 21. In the example shown in FIG. A coil spring 22 is attached to this shaft 21 to rotationally bias the hook 20 in the direction of the hour hand. A hole 23 into which the tip 20A of the hook 20 is inserted is formed at the tip of the leaf spring 11, and a pad 24 is fixed so as to wrap around the leaf spring. The state shown in FIG. 4 is the state in which the leaf spring 11 is locked to the cassette body.
The sheet 8 is separated by the claw 10 due to the elastic force of the leaf spring 11.
You can press A. To disengage this engagement and release the sheet receiving plate 7, it is sufficient to place a finger on the pad 24 and slightly push the leaf spring 11 inward of the cassette body against its elastic force. That is, when pressed in this way, the tip 20A of the hook 20 is pressed against the leaf spring 11.
By the action of the spring 22, the hook 20 rotates in the direction of the hour hand as shown by the imaginary line, and the leaf spring 17 disengages from the cassette body.

In the embodiment shown in FIG. 5, the hook 30 is slidably provided through the front wall of the cassette body.
Its inner end is adapted to engage with the tip of the leaf spring 11. To release the seat receiving plate 11, the hook 30 can be pulled forward.

6 shows still another example of the locking means, FIG. 6A is a sectional view, FIG. 6B is a plan view, and FIG. 6C is a front view. In this example, a hook 4 is attached to the tip of the leaf spring 11.
This hook consists of a fixed part 41 fixed to the leaf spring 11 and a sliding part 42 slidably disposed along the plane of the leaf spring. A compression coil spring 43 is disposed between the fixed part 41 and the sliding part 42, and biases the sliding part 42 to the left in FIG. 6A. When the seat plate (not shown) is closed, the tip 42 of the sliding portion 42
A is a protrusion 44 formed on the front wall 4B of the cassette body.
is engaged with. To release the sheet receiving plate, it is sufficient to place a finger on the rear end 42B of the sliding portion 42 and move it to the right in FIG. 6A, thereby retracting the leading end 42A. Further, when the seat receiving plate is closed, the sliding portion 42 automatically retreats due to the taper of the tip portion 42A of the sliding portion 42 and the protrusion 44. In this example as well, as clearly shown in FIG. 6C, the leaf spring 11
Since the hook 40 is attached so as to wrap around the user, the user can be protected from the sharp edges of the leaf spring 11, and the rigidity of this part of the leaf spring 11 can be increased.

FIG. 7 is a sectional view showing still another example of the paper feed cassette of the present invention. The configuration of the sheet receiving plate 7, leaf spring 11, and hook 14 in this example is the same as the example shown in FIGS. 1 to 3, except that in this example, the separation claw is not fixed but is attached movably. are different.
That is, in this example, the separation claw 10A is formed at the tip of an arm 51 that rotates around a shaft 50. This rotation of the arm 51 is caused by the fact that the protrusion 51A comes into contact with the upper surface 4A of the cassette body 4 and that the arm 51
The distal end portion 51B of the cassette body 4 is restricted by contacting the side wall of a recess 52 formed in the front wall 4B of the cassette body 4. The arm 51 and therefore the separating claw 10A can move freely within this range.

FIG. 8 is a sectional view showing still another embodiment of the paper feed cassette of the present invention. This example is the same as the above-mentioned example in that the sheet receiving plate 7 is rotatably attached to the cassette body 4 about the shaft 6, but one end of the leaf spring 60 as an elastic member is attached to the sheet receiving plate 7. The leaf spring 60 is not narrow as in the above example, but has a wide width approximately equal to the width of the cassette body 4, and the sheet receiving plate 7 is fixed to the center of the cassette body 4. This differs from the previous example in that a hook 61 for locking is attached to the sheet receiving plate 7, and the tip of the hook is engaged with a locking recess 17 formed in the front wall 4B of the cassette body. The structure of this hook 61 is the same as that shown in FIG. In this example as well, by closing the sheet receiving plate 7, the sheet 8 loaded in the cassette main body can be pressed against the separating claw 10A by the elastic force of the leaf spring 60.

The present invention is not limited to the above-mentioned example, and can be modified and changed in many ways. For example, the hook mechanism for locking the leaf spring 11 or the sheet receiving plate 7 to the cassette body 4 is not limited to the example described above, and various known locking mechanisms can be used. In the embodiment shown in FIGS. 1 to 7, one end of the leaf spring 11 is rotatably connected to the cassette body 4, and the leaf spring 11 and the seat receiving plate 7 are connected to the other end.
It is also possible to install a hook mechanism that separably engages the two. Furthermore, in the example described above, the seat receiving plate 7
Although the sheet receiving plate 7 is rotatably pivoted to the cassette body 4, it is also possible to attach the seat plate 7 to the cassette body 4 so as to be able to slide thereon or to be able to remove it completely.

The effects of the paper feed cassette of the present invention described above are summarized as follows.

(1) Since the lower surface of the cassette body is opened and sheets are loaded from there, the separating claws do not get in the way when loading sheets, making loading work easier and eliminating deformation of the leading edge of the sheets.

(2) Since the sheet receiving plate or the cassette body is equipped with an elastic member that presses the sheet against the separating claw when the sheet receiving plate is closed, there is no need to load the sheet against the elastic force of the elastic member, making the loading process easier. becomes easier.

(3) Since the elastic member that presses the sheet against the separating claw is provided on the cassette side, the structure of the sheet feeding device is simplified.

(4) When the elastic member is attached to the outer surface of the seat receiving plate, the elastic member can also be used as a handle for opening and closing the seat receiving plate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of an example of the paper feed cassette of the present invention, FIG. 2 is a plan view showing the back side thereof, FIG. 3 is a front view thereof, and FIGS. 4 and 5 are 6A, B and C are sectional views showing the structure of two other examples of paper cassettes; FIG. and FIG. 8 is a sectional view showing the structure of still another example of the paper feed cassette of the present invention. 1... Feeding cassette (paper feeding cassette), 2...
Paper feed roller, 4...Cassette body, 5...Window, 7
...Seat receiving plate, 8...Seat, 10A, 10B
... Separation claw, 11 ... Leaf spring, 14, 42, 61
... Hook, 17 ... Recessed part for locking, 60 ... Wide leaf spring.

Claims (1)

[Claims] 1. A large number of stacked sheets 8 can be stored, and means 2 and 3 for discharging the sheets one by one are provided on a part of the upper surface to act on the topmost sheet. A box-shaped cassette main body 4 having a window 5 and an open bottom surface, and a box-shaped cassette main body 4 having dimensions that cover almost the entire open bottom surface, and is attached to the cassette main body so that it can move slightly into the cassette main body. It is equipped with a sheet receiving plate 7 and separation claws 10A and 10B arranged near the window and having the function of separating the sheets one by one, and after the cassette main body is turned over, the sheet receiving plate is moved from the bottom surface. The sheet receiving plate is positioned so as to cover the open lower surface of the cassette body, and acts between the cassette body and the sheet to force the sheet into the separating claw. A feeding cassette characterized in that elastic members 11 and 60 that come into pressure contact are provided on the sheet receiving plate or the cassette body. 2. The feeding cassette according to claim 1, wherein the elastic member 11 is attached to the outer surface of the sheet receiving plate. 3. The feeding cassette according to claim 1, wherein said elastic member is comprised of a wide leaf spring 60 and is attached to the inner surface of said sheet receiving plate.