JPH0485220A - Cassette holding device - Google Patents

Abstract

PURPOSE:To position accurately a cassette by providing a protrusion in an cassette to contain recording paper sheets, a guide channel for the protrusion in an image forming apparatus body and a lever rotating energized with a spring and having a channel to fit the protrusion. CONSTITUTION:A downward protrusion 22 is provided in the bottom plate of a cassette 10, and a guide channel 23 for the protrusion 22 is provided in a support plate 20 of an image forming apparatus body. A lever 25 is attached to the support plate 20. The lever 25 turns around a pin 24, being energized with a spring 33. extended between fitting pieces 31, 32, and has a channel 26 to fit the protrusion 22. When the protrusion 22 of the cassette 10 is inserted into the guide channel 23 and pushed up to an intermediate point, the lever 25 turns around a pin 24 in the A direction shown by the arrow, being elastically energized with the spring 33, so that the protrusion 22 is pressed against the bottom of the channel 23 and the cassette 10 is held at a specified position. To withdraw the cassette 10, the cassette 10 is pulled out up to a midway point, when a spring force line T thus goes beyond a datum line P, the cassette is automatically ejected. Accordingly the cassette is positioned accurately, and easily ejected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cassette holding device that holds a cassette for storing recording sheets in a stacked manner in a main body of an image forming apparatus such as a printer or a copying machine in a detachable manner.

Problems to be Solved by the Prior Art and the Invention In image forming apparatuses such as various printers such as laser printers and thermal printers and copying machines, a large number of sheet-shaped recording papers are stacked and stored in a paper feed cassette. An image is formed on the recording paper fed from there.

To enable such an image forming device to form an image at a predetermined position on recording paper, and to ensure that recording paper is fed from a cassette to an image forming section without jamming. Therefore, the cassette must always be positioned at a predetermined position with respect to the main body of the image forming apparatus.

Moreover, loading the cassette into the main body of the device is done frequently every time the recording paper in the cassette runs out, so it is easy for the operator to load the cassette into a predetermined position without requiring much force. desirable.

An object of the present invention is to enable the cassette to be easily positioned at a predetermined position relative to the main body of the image forming apparatus by simply pushing the cassette into the cassette insertion opening of the image forming apparatus.

Means for Solving the Problems To achieve the above object, the present invention provides a cassette holding device that removably holds a cassette containing recording paper in a cassette insertion slot of an image forming apparatus, in which the cassette and the main body of the apparatus are connected to each other. An engagement protrusion is provided on one side, a lever is rotatably attached to the other side, and an engagement groove in which the engagement protrusion engages is provided at the tip of the lever, and when the cassette is removed, the lever The tip of the lever is directed toward the cassette insertion opening of the apparatus main body, and a spring member that applies a resilient force to the lever in the direction of pushing the cassette when the cassette is at a predetermined insertion position is attached to the lever. This is a cassette holding device prepared for

Operation In the cassette holding device having the above structure, when the cassette is pushed into the cassette insertion port to load the cassette into the main body of the device, the engaging protrusion engages with the engaging groove of the lever. When the cassette is subsequently pushed in, the lever rotates and when the lever passes a predetermined rotational position, a spring member connected to the lever applies an elastic force to the cassette in the direction of pushing it in. will be done. Thereby, the cassette is automatically positioned at a predetermined position within the main body of the apparatus. vice versa,
When removing the cassette, when the cassette is pulled out to a predetermined position, an elastic force is applied in the direction of pulling out the cassette, and the cassette can be removed smoothly.

EXAMPLES Hereinafter, the present invention will be explained in detail based on the illustrated examples.

FIG. 1 is a schematic cross-sectional view showing an example of a laser beam printer, and an image forming section 2 is incorporated in the center of a housing 1 of a printer main body forming an image forming apparatus main body. The image forming section 2 includes a photosensitive drum 3, a charger 4, a developing device 5, a transfer charger 6, and a cleaning device 7 arranged around the photosensitive drum 3. A laser device 8 is provided above the photoreceptor drum 3 to irradiate the outer peripheral surface of the photoreceptor drum 3 with laser light in accordance with image information.

Recording paper 11 stored in a stacked state in a cassette 10
is fed out by the paper feed roller 12 and then conveyed to the timing roller 14 by the conveyance roller 13. The recording paper 11 is conveyed between the photoreceptor drum 3 and the transfer charger 6 at a predetermined timing by the timing roller 14, and the toner image formed on the outer peripheral surface of the photoreceptor drum 3 is transferred onto the recording paper 11. Ru. After the transferred toner image is thermally fused to the recording paper 11 by the fixing roller 15, the recording paper 11 is conveyed to the paper discharge tray 17 by the paper discharge roller 16.

FIG. 2 is a diagram showing the state in which the cassette 10 is removed from the apparatus main body 1, and the cassette 10 has a bottom wall portion 10a and a rear wall portion 1.
0b, a front wall portion 10c, and left and right side walls 10d, and has a rectangular box shape with an open top. and,
A support member 20 is provided at the bottom of the apparatus body 1 to support the bottom wall portion 10a of the cassette 10 when the cassette 10 is attached or detached. When the cassette 10 has been completely loaded, the cassette 10 is positioned by directly contacting the inner surface of the main body 1 of the apparatus, or by using a positioning member (not shown). Support members (not shown) may be brought into contact with the left and right side walls 10d of the cassette 10 to slidably support the cassette 10. When loading the cassette 10 into the apparatus main body 1, the cassette 10 is
The cassette is inserted from the cassette attachment/detachment opening formed in the apparatus main body 1, that is, the cassette insertion opening 21, with b as the tip.

As shown in FIG. 2, an engaging protrusion 22 is provided on the lower surface of the bottom wall portion 10a of the cassette 10, and the engaging protrusion 22 is provided on the apparatus main body 1 in order to guide the engaging protrusion 22 when the cassette 10 is attached or detached. As shown in FIG. 3, a guide groove 23 is formed in the assembled support plate 20. A lever 25 is attached to the lower surface of the support plate 20 so as to be rotatable about a support shaft 24 . An engagement groove 26 with which the engagement protrusion 22 engages is formed along the longitudinal direction of the lever 25 at the tip of the lever 25. It's open. In FIG. 3, reference numeral 27 indicates a shaft hole into which the support shaft 24 is fitted.

The lever 25 extends from a position where the tip of the lever 25 faces the front of the device main body 1, as shown in FIG. 4(A), to a position where the tip of the lever 25 faces the rear end, as shown in FIG. 4(B). The guide groove 23 and the engagement groove 26 overlap in the 20 rotation range. Figure 4 (A
) The lever 25 is set to the position shown in FIG. 2 when the cassette 10 is removed. It is installed protrudingly. In this state, the engagement groove 26 intersects the guide groove 23 at an obtuse angle. Lever 2
A stopper 31 is provided to protrude downward between the shaft hole 27 and the engagement groove 26 of the support plate 2.
A tension coil spring 33 is attached to a stop 32 protruding from the lower surface of 0.

The tension coil spring 33 allows the stop 31 to
2, and the direction in which this resilient force, that is, the spring force is applied, is indicated by the symbol T in FIG. 4(A).
It is as follows. If the reference line connecting the center of the support shaft 24 and the center of the stopper 32 is P, then as shown in FIG. 4(A), when the cassette 10 is removed, the stopper 3
1 is located in front of the device main body 1 rather than the support shaft 24, the tension coil spring 33 applies an elastic force to the lever 25 in the counterclockwise direction in the figure. This elastic force is the lever 2
5 in the direction in which the engagement grooves 26 are opposed to the front of the device main body 1.

When the cassette 10 is pushed into the cassette loading section of the apparatus main body 1, the engagement protrusion 22 is guided by the guide groove 23, advances through this groove 23, and engages with the engagement groove 26 of the lever 25. In this state, when the cassette 10 is further pushed in against the elastic force of the tension coil spring 33, the lever 25 is moved to the fourth position.
Rotates clockwise in figure (A). When the lever 25 rotates to a position beyond the position where the spring force line T coincides with the reference line P as a result of this rotation, the stop 31 is positioned further back than the support shaft 24 with respect to the main body 1 of the device. Therefore, the tension coil spring 33 applies an elastic force to the lever 25 in the clockwise direction in FIG. 4(B). The elastic force in this direction acts in the direction of pushing the cassette 10,
This resilient force automatically pulls the cassette 10 into position. FIG. 4(B) shows the engagement protrusion 22 and lever 25 in a state where loading of the cassette 10 is completed.
In this state, the cassette 10 is positioned at the regular position shown in FIG. 1.

As shown in FIG. 4(B), when removing the cassette 10 from the loaded state where it is in a predetermined position, the operator must move the cassette 10 against the elastic force so that the spring force line T is the reference point. Once the cassette 10 is pushed out beyond the line P, an elastic force is applied to the cassette 10 in the direction of pushing it out. This facilitates the operation of removing the cassette 10.

As mentioned above, the tension coil spring 33 is a member that applies elastic force in the direction of pushing the cassette 10 after the cassette 10 is pushed to a predetermined position, and if this condition can be achieved, For example, various spring members such as a compression coil spring can be used in place of the tension coil spring 33. For example, when using a compression coil spring, the positions of the stop 31 and the support shaft 24 are opposite to each other in the longitudinal direction of the lever 25.

Although FIG. 3 shows a support plate 20 for slidably guiding the lower surface of the cassette 10, rail members that support the left and right sides of the cassette 10 are attached, so that the cassette 10
You may also support it. In that case, cassette 1
Since the center portion of the bottom wall portion 10a of 0 does not come into contact with the support plate 20, it is also possible to attach the lever 25 to the upper surface of the support plate 20, and in this case, the guide groove 23 becomes unnecessary. Further, in the illustrated embodiment, the engaging protrusion 22 is provided on the bottom wall portion 10a of the cassette 10, but the engaging protrusion 22 is provided on one or both of the left and right side wall portions 10d,
The lever 25 that engages with the engagement protrusion 22 is inserted into the cassette 1.
It may also be installed in the device main body 1 in correspondence with the side wall portion of the device 0.

The entire top surface of the illustrated cassette 10 is open, but
A cover member (not shown) may be attached to the cassette 10 except for the portion from which the recording paper 11 is taken out, and the engagement protrusion 22 may be attached to this cover member. In that case,
A lever 25 is attached to a position corresponding to the lid member.

Furthermore, in the embodiment described above, the lever 25 is attached to the main body of the device, and the engaging protrusion 22 that engages with the lever 25 is provided.
is attached to the cassette 10, but the engaging protrusion 22 is attached to the device main body side, and the lever 2 that engages with the engaging protrusion 22
5 may be attached to the cassette side.

Although FIG. 1 shows a laser beam printer, the above-mentioned cassette holding device can be applied to other image forming apparatuses that use a cassette for storing stacked sheets of recording paper, such as copying machines and thermal printers. The present invention can be applied to any type of material.

Effects of the Invention As described above, according to the present invention, when the cassette is pushed into the cassette insertion slot of the image forming apparatus to a predetermined position, an elastic force is applied to the spring member in the direction of pushing the cassette. However, the cassette is automatically positioned at a predetermined position. This ensures that recording paper is fed from within the cassette.

[Brief explanation of drawings]

Figure 1 is a schematic sectional view showing a laser beam printer, Figure 2 is a partially omitted sectional view showing the laser beam printer shown in Figure 1 with the cassette removed, and Figure 3 is a main part of the main body of the device. FIGS. 4(A) and 4(B) are plan views showing the operating state of the cassette holding device. DESCRIPTION OF SYMBOLS 1... Device body, 10... Cassette, 20... Support plate, 22... Engagement protrusion, 25... Lever, 26...
...Engagement groove, 33...Spring member. Figure 1

Claims (1)

[Scope of Claims] A cassette holding device that removably holds a cassette containing recording paper in a cassette insertion slot of an image forming apparatus, comprising: an engaging protrusion provided on one of the cassette and the main body of the apparatus;
A lever is rotatably attached to the other side, and the tip of the lever is provided with an engagement groove in which the engagement protrusion engages, and when the cassette is removed, the tip of the lever is attached to the cassette of the device main body. The cassette holding device includes a spring member on the lever that is directed toward an insertion opening and that applies a resilient force to the lever in a direction to push the cassette when the cassette is at a predetermined insertion position.