JPH04303333A - Paper sheet feed cassette - Google Patents

Abstract

PURPOSE:To easily change a sheet size by making adjustable the pressing force of an elastic body for pushing up a presser plate used in a paper sheet feed cassette. CONSTITUTION:A punched hole 24b is formed at the mounting section of a coil spring 25 on the bottom 24a of a paper sheet feed cassette 24, thereby enabling the pressing force of the spring 25 to be easily adjusted. As a result, the pressing force of a presser plate on the bottom of the cassette 24 by the spring 25 is made changeable and many types of recording sheets can thereby be loaded into the cassette 24.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to pressure adjustment of an elastic body for pushing up a recording paper pressing plate of a paper feed cassette used in recording devices such as copying machines and printers.

0002

[Prior Art] In a method generally used for paper feed cassettes, a recording paper pressing plate provided inside the paper supply cassette body is constantly pushed up by an elastic body (mainly a coiled spring), and both sides of the leading edge of the recording paper are pushed up. There is a method that separates the paper into individual sheets using a separation claw and then feeds the paper. Conventional paper feed cassettes are usually formed to a size that corresponds to the size of the recording paper, and the weight of the paper varies depending on the size of the paper when stored in the paper feed cassette, especially at the maximum number of sheets. It is adjusted to make the pressing force uniform when pressing against the roller. However, in recent years, there has been a demand for overall miniaturization of copying machines, and the conventional method of mounting the paper feed cassettes from the sides has been changed to a method of mounting them from the front as shown in Figure 5. This makes it possible to downsize the product using a method that does not make it stand out. However, when using such a configuration, if multiple paper cassettes are installed from the front of the copier as shown in Figure 5, with the paper cassettes sized to correspond to the size of the recording paper, the size of each paper cassette will vary. Therefore, a specialized mounting opening must be provided, and it is difficult to manufacture, and it is also inconvenient to attach and detach the paper feed cassette. Further, there are drawbacks such as high production costs. Therefore, paper feed cassettes were made to be the same size regardless of the size of the recording paper, and paper of different sizes was fed.However, as mentioned above, the weight of the maximum number of sheets stored depends on the size of the recording paper. Adjustment is required due to the difference, but this adjustment is performed using an elastic member of a coiled spring to push up the pressing plate. However, once the coiled spring is attached below the pressure plate, it is impossible to easily attach or detach the coiled spring even if the user wants to change to only the required size of recording paper, and the pressure It has the disadvantage that it cannot be adjusted.

0003

SUMMARY OF THE INVENTION The present invention has been devised to eliminate the above-mentioned drawbacks. That is, the above-mentioned drawbacks are solved by making it possible to adjust the pressure of the coiled spring provided at the bottom of the paper feed cassette in accordance with the size of the recording paper contained in the paper feed cassette. .

0004

[Means for Solving the Problems] A recording paper push-up plate on which a recording paper is placed and pushed up to a paper feeding device; a recording paper guide plate provided on both sides of the recording paper for guiding it; In a paper feed cassette having a separation claw for separating paper and an elastic member that pushes up the recording paper through the push-up plate, the pressure of the elastic member provided in the paper feed cassette can be adjusted. This is achieved by providing an adjustment member.

[0005]

Embodiment FIG. 4 is a block diagram of the entire copying apparatus for using the paper feed cassette of the present invention, in which 1 is a photoreceptor drum, 2 is a charging electrode that applies a constant charge to the entire surface of the photoreceptor drum 1, and 3 5 is a developing device equipped with a toner replenishing section 4; 5 is a cleaning device equipped with a cleaning blade 6 for removing residual toner from the photosensitive drum 1; the above devices are manufactured as an integral structure; It is removably provided at 7a. Further, the upper frame 7a includes an original platen glass 8 for placing the original, a document holding plate 9 for pressing and holding the original when the original is placed on the original platen glass 8, and a document holding plate 9 for pressing and holding the original when the original is placed on the original platen glass 8. Exposure lamps 10 are moved by guide rails (not shown) to the positions indicated by the dashed-dotted lines at the lower positions of the original platen glass 8.
, a first reflecting mirror 11 that moves together with the exposure lamp 10, and integrated V-shaped mirrors 13 and 14 that project the light received from the first reflecting mirror 11 onto a focusing lens 12, and A fixed mirror 15 is provided for irradiating the surface of the body drum to form an electrostatic latent image. 16
is an exhaust fan for discharging heat generated in the copying device to the outside, and is provided with suction ports 17 and 18. The suction port 17 removes toner scattered from the developing device 3 and ozone generated from the charged electrode 2. It is discharged to the outside through filter F. On the other hand, the heat from the exposure lamp 10 generated within the optical system above the optical system is discharged to the outside through a suction port 18 formed in a light shielding plate 7b for shielding the optical system. The V-shaped mirrors 13 and 14 are moved by a guide rail (not shown) by half the distance that the exposure lamp 10 is moved, so that the optical path length between the original and the surface of the photoreceptor drum is always kept constant. There is. Reference numeral 23 denotes a cooling fan for cooling the document table glass 8, and is provided on the side of the frame.

Reference numeral 24 denotes a paper feed cassette which is provided at the lower part of the lower frame 7c of the copying device 7 and stores recording paper P, which will be described in detail in FIG. 25, the front part in the paper feeding direction is pushed up via the press plate 26, and the uppermost recording paper P is fed by the half-moon-shaped paper feed roller 27, and then transferred to the second paper feed roller by the conveyance roller 28 and the guide part 29. 30. The second paper feed roller 3
The second paper feed roller 30 operates so that the recording paper P, which has stopped at 0, coincides with the toner image developed by the developing device 3 on the surface of the photoreceptor drum. 31 is a transfer pole for transferring the toner image formed on the first surface of the photoreceptor drum onto the recording paper P; 32 is a separation pole for separating the recording paper P from the first surface of the photoreceptor drum; 33 is a transfer pole for separating the recording paper P from the first surface of the photoreceptor drum; This is a fixing device for fixing the transferred toner image. Further, the lower frame body 7c is provided with a single-sheet manual feeder 34 and a multiple-sheet manual feeder 35, each of which is provided so that paper is fed by a half-moon-shaped paper feed roller 36.

Further, as shown in FIG. 4, the paper feed cassette 24 has two
Paper feed cassettes 24 of the same type are installed in stages. The lower paper feed cassette 24 is mounted on a pedestal 37 and is transported to the copying device 7 via a common transport roller 28. As shown in FIG. 5, if a plurality of stages 37 each having a common paper feed cassette 24 mounted thereon are prepared, the paper feed performance can be increased or decreased as appropriate.

Next, regarding the paper feed cassette 24 of the present invention,
This will be explained with reference to FIG. The paper feed cassette 24 is made of resin or the like, and has a front wall 241, a rear wall 242, and side walls 243 and 244, respectively.
The front wall 241 is provided with a handle 245 so that it can be attached to and detached from the copying device 7 shown in FIG. 4 in the direction shown by the arrow in FIG.

As mentioned above, numeral 26 is a pressing plate on which a large number of recording papers P are placed and for pressing the recording papers P against the paper feed roller 27 provided in the copying device 7. The pressing plate 26 is shown in FIG. As shown in FIG. 2, one end is supported within the paper feed cassette 24 and the other end is pushed up by a coiled spring 25. 246,2
47 is a recording paper guide plate that allows the recording paper P to be placed in a predetermined position in the paper feed cassette 24 and to feed the paper correctly;
Long grooves 248 and 249 are provided in the bottom 24a of the paper feed cassette 24 so that the recording paper can be guided in the width direction depending on the size of the recording paper to be stored.
will be established. Further, the recording paper guide plates 246, 247 are provided with separation claws 246a, 247a for separating the recording paper P. Reference numeral 250 denotes a regulating plate provided to place the rear end of the recording paper P at a predetermined position, and a long groove 251 is provided in the bottom portion 24a of the paper feed cassette 24 so that the position can be adjusted.

Although not shown in FIG. 1, as shown in FIG. 4, the paper feed cassette 24 has a coiled spring 25 that pushes up the pressing plate 26 as described above.
As shown in FIG.
An inclined surface 252 is formed on the upper part of a fixed plate 259 fixed to 4a, a sliding member 253 is slidably provided on the fixed plate 259, and an elastic member 254 is provided on one side of the sliding member 253.
A pressure adjusting screw 255 is provided on the other side, and the sliding member 253 is provided so as to be able to move slightly with respect to the fixed plate 259 using the pressure adjusting screw 255. On the other hand, the sliding member 253
A pressing member 257 having an inclined surface 256 is provided in contact with the inclined surface 252 at the top, and a receiving member 258 for the coiled spring 25 fixed on the pressing member 257 is provided. The receiving member 2
58 is provided so as to always maintain a horizontal position as shown in FIG. The receiving member 258 is disposed within a hole 24b formed in the bottom portion 24a, and is configured to receive the lower portion of the coiled spring 25. Also, as a method of fixing the fixing plate 259, use screws 251 as shown in FIG.
a and the pressure adjustment screw 255, but the method is not particularly limited to this method. Next, FIG. 3 shown as another embodiment will be explained. A flange 261 is formed outside the hole 24b formed in the bottom 24a, and a cylinder 263 with a female thread 262 is fixed inside the flange 261. A receiving member 264 for the coiled spring 25 is provided which fits into the female thread 262 formed in the cylinder 263. The receiving member 2
62 is formed with a male thread 265 that is screwed into the female thread 262, and the lower end of the coiled spring 25 is connected to the receiving member 264.
and the female thread of the cylinder 263 and the male thread 2 of the receiving member 264.
65 are screwed together, and the spring pressure of the coiled spring 25 can be adjusted by rotating one end of the receiving member 264. Since the present invention is configured as described above, for example, when the paper feed cassette 24 that is attached to the copying machine 7 and feeds paper is used in multiple stages as shown in FIG. Coiled spring 2 depending on the size of
The elastic force of the coil spring 25 can be adjusted in accordance with the weight of the maximum number of sheets that can be loaded when loading A4 size recording paper into the paper feed cassette 24. adjust. As for the adjustment method, first, use the pressure adjustment screw 255 provided outside the bottom 24a of the paper feed cassette 24.
is rotated left and right to slide the sliding member 253 to the right or left with respect to FIG. In this case, when sliding to the left, the receiving member 258 is raised by the action of the inclined surface 256 of the pressing member 257 due to the inclined surface 252, increasing the pressure of the coiled spring 25. Conversely, if it slides to the right, the above action is reversed, and the receiving member 258 descends, weakening the pressure on the coiled spring. Due to the pressure adjustment function described above, there is no need to incorporate a specific recording paper P into the paper feed cassette 24, and it becomes possible to incorporate recording paper of any size as needed.

Next, FIG. 3 in another embodiment will be explained. By rotating the receiving member 264 to the right or left, the receiving member 264 can be finely adjusted up and down by the action of the male thread 265 of the receiving member 264 and the female thread 262 of the cylinder 263, and the pressure of the coiled spring 25 can be adjusted. Can be done. The coiled spring 25 can be removed from the bottom 24a of the paper feed cassette 24 and replaced by rotating the receiving member 264 in the direction of loosening the spring pressure and removing the receiving member 264 from the cylinder 263. Therefore, it is also possible to incorporate a wider variety of recording papers.

0012

Effects of the Invention As described in detail above, the present invention is particularly advantageous when a plurality of paper feed cassettes of the same type are used in a copying machine or the like as shown in FIGS. 4 and 5. , the user can freely change the size of the recording paper in the paper cassette depending on the usage condition of the size, and even if the weight of the recording paper changes due to the change, the coil shape of the push-up plate for each paper cassette can be easily adjusted. The spring pressure can be adjusted, and the user can store the most desired recording paper in the paper feed cassette.

[Brief explanation of drawings]

1 is a perspective view of the paper feed cassette of the present invention, FIG. 2 is a cross-sectional view showing the relationship between a copying device and the paper feed cassette of the present invention, FIG. 3 is a cross-sectional view showing another embodiment of the paper feed cassette, and FIG. 5 is a sectional view of a copying apparatus equipped with a two-stage paper feeding cassette, and FIG. 5 is an explanatory diagram showing the relationship between the copying apparatus and the multi-stage paper feeding cassette.

[Explanation of symbols]

Claims (1)

[Claims] 1. A recording paper push-up plate on which recording paper is placed and pushed up to a paper feeding device, a recording paper guide plate provided on both sides of the recording paper for guiding it, and separating the recording paper. In the paper feed cassette, the paper feed cassette has a separation claw for pushing up the recording paper and an elastic member that pushes up the recording paper through the push-up plate, and an adjustment member is provided that can adjust the pressure of the elastic member provided in the paper feed cassette. A paper feed cassette characterized by: