JPH04333431A - Paper feeding device - Google Patents

Abstract

PURPOSE:To smoothly draw a paper feeding deck by easily releasing a coupling pair connected to the lifter plate of a paper feeding deck of a front loading system. CONSTITUTION:A pair of couplings 7 and 9 is provided between a drive system (wires 5 and 6), elevating a lifter plate 3 of a paper feeding deck 2, and a drive part 70 on a machine main body side 4 side. A gap G is formed between the coupling female 7 and the coupling male 9 when they are released for drawing the paper feeding deck 2. This eases releasing them, enabling smoothly drawing the paper feeding deck 2 from the machine main body side.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front-loading paper feeding device that is attached to an image forming apparatus and feeds sheets to the image forming apparatus.

0002

2. Description of the Related Art Conventionally, as a paper feeding device included in an image forming apparatus such as a copying machine, there has been known a front loading type paper feeding device which is installed next to the main body of the image forming apparatus. This paper feeding device includes a plurality of paper feeding decks and is capable of feeding a large amount of paper.

FIG. 10 shows the configuration of a conventional paper feeding deck section in the above-mentioned paper feeding device. In the figure, a lifter plate 6 on which sheets P are loaded is disposed in a deck case 5A that is open at the top. This lifter plate 6
moves up and down while sliding inside the deck case via a slide section 65 provided on its side. The lifter plate 6 is driven by transmitting the rotation of a motor provided in the machine body (not shown) via a coupling (not shown).

The sheets P stacked on the lifter plate 60 are regulated in the width direction by a pair of sheet width regulating plates 41 and 42 provided on the lifter plate 60, and are regulated in the width direction by a sheet trailing edge regulating plate 43. The edges are regulated. The bracket 45 fixed to the back side of the deck case 5A has a
A lock roller 46 is pivotally mounted. When the deck case 5A is pushed into the machine body (not shown) of the paper feeder,
By coupling the locking roller 46 to the locking pawl 49 of the locking unit 40 disposed on the machine main body, the paper feed deck is positioned in the drawing direction with respect to the storage unit of the machine main body.

Next, the lock unit 40 fixed to the frame 47 of the storage unit that houses the paper feed deck will be explained.

A support member 51 is removably attached to the frame 47 of the storage unit with a plurality of screws 63, and a lock claw 49 is attached to the support member 51 on the support shaft 5.
2, it is rotatably mounted. The lock claw 49 is
It is biased counterclockwise in the figure by the elasticity of a tension spring 56 whose both ends are locked to the mounting plate 55 and the lock pawl 49, and the other end of the lock pawl 49 is connected to the solenoid 53 via a connecting lever 62. connected.

The claw portion 57 of the lock claw 49 is formed in an arc shape around the support shaft 52, and when the paper feed deck is pushed in and set in the storage unit, the claw portion 57 engages with the lock roller 46. to lock the paper feed deck so that it cannot be pulled out. A stopper 5 made of rubber is attached to the support member 51 of the frame 47 of the storage unit of the machine body.
9 is fixed and acts as a stopper when the paper feed deck is pushed in.

The base of a leaf spring 61 is fixed to the support member 51, and the leaf spring 61 acts in a direction to push back the pushed paper feed deck forward. As a result, the locking roller 46 and the claw portion 57 of the locking claw 49 are always in contact with each other, and the sheet feeding deck is positioned in the drawing direction.

When the paper feed deck is pushed in, the lock roller 4
At the same time that the paper feed deck is locked by 6 and the claw portion 57, the motor that raises the lifter plate 60 is turned on.
The rotation is transmitted to the lifter plate 60 via a coupling (not shown), and the lifter plate 60 is raised. Next, press the deck pull-out button (not shown) to turn on the motor.
However, this time, the lifter plate 60 is lowered in the reverse direction. When the lifter plate 60 comes to the lower predetermined position, the solenoid 53
is turned on, the lock pawl 49 rotates to the chain line position, and the leaf spring 6
1 is displaced by d1 in the direction of arrow 66, pushing the paper feed deck back a little in the pull-out direction.

0010

[Problems to be Solved by the Invention] However, in the above-mentioned conventional device, when the paper feed deck is pulled out,
The coupling pair that transmits the driving force of the motor to the lifter plate 60 may not come off, which poses a problem in terms of reliability. Note that it is possible to strengthen the spring pressure of the leaf spring 61 for pushing out the paper feed deck to increase the pushing force, but if the spring pressure of the leaf spring 61 is strengthened, the lock roller 46 will come off from the lock pawl 49. Therefore, there is a limit to increasing the spring pressure of the leaf spring 61.

Accordingly, the present invention makes it possible to easily pull out the coupling pair that transmits the driving force of the drive source to the drive system of the lifter plate when pulling out the paper feed deck, so that the operation of pulling out the paper feed deck can be performed stably. It is an object of the present invention to provide a paper feeding device as described above.

0012

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide an image forming apparatus (1) so that stacked sheets (P) can be fed to the image forming apparatus (1).
1), there is a front-loading type paper feed deck (
2), a lifter plate (3) provided in the paper feed deck (2) so as to be vertically movable and on which sheets (P) are loaded;
A paper feeding device that drives the lifter plate (3), and includes a drive source (70) provided on the machine body (4) side, and a drive source (70) and the paper feed deck (
A pair of couplings (7, 9) serving as a connection means for connecting the drive system (5, 6) of the lifter plate (3) on the side 2), and the pair of couplings (7, 9) When the connection is released, the male side (9) and the female side (
7) is characterized by providing a gap (G) between the two.

[0013]

[Operation] Based on the above structure, the sheets (P) stacked on the paper feed deck (2) are raised and lowered by driving the drive section (70). The drive unit (70) is driven via a coupling pair (10) provided in the drive unit (70) and the drive system (5, 6) on the lifter plate (3) side.

When pulling out the paper feed deck (2) from the machine body side (4) of the sheet conveying device, the lifter plate (3)
is lowered to the lowest position, and at the time of this lowering, a gap (G) is formed between the coupling male (9) and the coupling female (7) of the coupling unit (10). . By forming this gap (G), the coupling female (
7) and the male coupling (9) can be easily released, thereby making it possible to smoothly pull out the paper feed deck (2) from the machine body side (4).

Note that the above-mentioned symbols in parentheses are shown for reference to the drawings, and do not limit the structure of the present invention in any way.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Note that the same meanings as those shown in Figure 10 are:
The same reference numerals are used to omit the explanation.

FIG. 2 shows a copying machine 1 as an image forming apparatus to which the present invention is applied. In the figure, a photosensitive drum 22 that rotates in the direction of the arrow is disposed within an apparatus main body 21 of a copying machine 1. Reference numeral 25 indicates an automatic document feeder that feeds documents one by one onto the platen glass 23, and 26 indicates an optical system that exposes the document and irradiates the photosensitive drum 22 with reflected light.

A plurality of paper feed decks 2 storing a large number of sheets P are arranged below the photosensitive drum 22, and a sheet P from any of the paper feed decks 2 is transferred to a paper feed roller. 12 to a pair of registration rollers 27, and then to the photosensitive drum 22 at an appropriate timing. The sheet P, onto which the toner image formed on the photosensitive drum 22 has been transferred, is conveyed to the fixing device 30 by the conveying means 29, and the toner image is fixed thereon.

In the case of normal copying, the sheet P is attached to the flapper 3
1 and discharged to the post-processing device 33, and in the case of multiplex or double-sided copying, the paper is guided to the paper refeeding section 35 including an intermediate tray, and then subjected to image processing by the photosensitive drum 22 again. The paper feed deck 2 is a front-loading paper feed deck that is inserted into and taken out from the main body 21 of the copying machine 1 from the operation side (the front side in the figure).

FIG. 3 shows a front view of the paper feed deck 2, FIG. 4 shows a rear view, and FIG. 5 shows a side view. In the figure, reference numeral 3 indicates a lifter plate 3 on which sheets P are loaded.
The end portions of wires 5 and 6 serving as a drive system on the lifter plate 3 side are respectively locked via fasteners 13 on both sides thereof. The wire 5 is connected to the wire 5 on the opposite side via a pulley 15 and a pulley pair 16 pivotally supported on the other side of the lifter plate 3. Moreover, the wire 6 is
They are connected to each other via a pulley pair 15 and a pulley pair 16.

Deck case 2 of paper feed deck 2 shown in FIG.
The wires 5 and 6 are wound at appropriate positions on the back side of the deck case 2A around a winding portion (not shown) of a coupling female 7 that is pivotally supported by the deck case 2A. A coupling female 7 and a coupling male 9 (
(see FIG. 1) constitute a coupling pair 10. FIG. 1 shows the side of the coupling male 9 and the side of the drive unit 70. Reference numeral 9a indicates a claw portion 9a of the male coupling 9, which can be inserted into or released from the engagement hole 7a of the female coupling 7 to close the coupling unit 1.
0 can be locked. The male coupling 9 is non-rotatably but slidably attached to the support shaft 71, and is supported by the elasticity of a compression spring 75 disposed between the spring receiver 73 fixed to the support shaft 71 and the male coupling 9. ,
It is biased toward the free end in a state where it is prevented from coming off.

A gear 72 fixed to the support shaft 71 is connected to a lifter motor 20 via a gear train, and this lifter motor 20 is fixedly installed on the machine body side 4. The lifter motor 20 and the gear train constitute a drive section 70. Further, on the back side of the deck case 2A in which the coupling knife 7 is disposed, a lock unit 4 for locking the paper feed deck 2 to the machine body side 4 is provided.
0 (see FIG. 6), and the structure and operation of this lock unit 40 are the same as those shown in FIG. 10, so a description thereof will be omitted.

Next, the operation of the paper feed deck 2 will be explained.

The sheet P is placed on the lifter plate 3 of the paper feed deck 2.
When the paper feed deck 2 is pushed into the machine main body side 4, the lock rollers 46 and lock claws 49 shown in FIG. 6 engage, and the paper feed deck 2 is locked to the machine main body side 4. At the same time, the engagement hole 7a of the female coupling 7 on the paper feed deck 2 side is engaged with the claw portion 9a of the male coupling 9 on the machine body side 4 side, so that the coupling pair 10 is connected.

When the lifter motor 20 is rotated in this state, its driving force is transmitted to the wire 5 via the coupling pair 10.
, 6, and the lifter plate 3 is raised. on the other hand,
When the lifter plate 3 is lowered, the lifter motor 20 is reversely rotated and the coupling pair 10 is rotated in the opposite direction to let out the wires 5 and 6 from the wire winding portion of the coupling knife 7.

When the lifter plate 3 descends and reaches the lowest position, that is, the bottom plate of the paper feed deck 2, a microswitch (not shown) is turned on. The lifter motor 20 is designed to stop several tens of milliseconds after the microswitch is turned on, and due to the time difference between the operation of this microswitch and the lifter motor 20,
A gap G is formed between the male side and the female side of the coupling pair 10. Due to the formation of the gap G, the female coupling 7 can be easily removed from the male coupling 9.

At the same time as the lifter motor 20 is turned off, the solenoid 53 shown in FIG. 6 is turned on, and the lock pawl 49 unlocks the lock roller 46. At the same time, the paper feed deck 2 is pushed out by the elasticity of the leaf spring 61, so that the paper feed deck 2 smoothly pops out from the machine main body side 4. When the paper feed deck 2 is ejected, the coupling pair 10 can be easily released as described above, so that no resistance is generated by the coupling pair 10 when the paper feed deck 2 is pulled out.

FIG. 7 shows a flowchart when the paper feed deck 2 is pulled out. In the figure, when the user operates a deck drawer button (not shown) (S1),
The lifter motor 20 for raising and lowering the deck is turned on (S2), and the paper feeding deck 2 is lowered (S3). When the paper feed deck 2 is lowered, a microswitch (not shown) is turned on and it is detected that the paper feed deck 2 has been lowered to a predetermined position (S4
), several tens of milliseconds after this ON operation, the lifter motor 20
stops (S5). This value of several tens of milliseconds is a designed value in this embodiment, and does not limit the configuration of the present invention in any way. Then, in a state where a gap G is formed between the female coupling 7 and the male coupling 9 so that the female coupling 7 and the male coupling 9 can easily come out, the female coupling 7 is disengaged from the male coupling 9 (S6).

Next, a second embodiment of the present invention is shown in FIGS. 8 and 9.
Shown below. In the embodiment described above, the landing of the lifter plate 3 on the bottom plate of the paper feed deck 2 is detected by a microswitch (not shown), but in this embodiment, it is detected by a change in the current of the lifter motor 20. It is something. FIG. 8 is a circuit diagram related to the lifter motor 20 for raising and lowering the sheet feeding deck 2, and FIG. 9 shows changes in the current flowing through the lifter motor 20.

[0030] Now, when the user presses the deck pull-out button (not shown), the lifter motor 20 is turned on.
The lifter plate 3 begins to descend. While the lifter plate 3 is descending, the load on the lifter motor 20 is large, so the current value is a large value (A) as shown in FIG. When the lifter plate 3 lands on the bottom plate of the paper feed deck 2, the load applied to the lifter motor 20 becomes a small value (B) as shown in FIG. Landing of the paper feed deck 2 is detected by this decrease in the current value of the lifter motor 20, and the lifter motor 20 is stopped several tens of milliseconds after the detection.

In this way, after the lifter plate 3 lands on the ground, the lifter motor 20 is driven for several tens of milliseconds as described above.
A gap G is formed between the coupling female 7 and the coupling male 9, so that the coupling female 7 and the coupling male 9 can be easily released, and the paper feed deck 2 is connected to the machine body side 4.
It becomes possible to pull it out smoothly.

[0032]

[Effects of the Invention] As explained above, according to the present invention,
In a front-loading paper feeder that supplies sheets to an image forming apparatus, a coupling knife connects the drive system for the lifter plate and the drive source that raises and lowers the lifter plate when the paper feed deck is pulled out from the main body of the paper feeder. Since a gap is formed between the coupling male and the coupling male,
The pair of couplings can be easily released, thereby making it possible to smoothly take the paper feed deck in and out of the machine body.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of a lifter plate drive source section of a sheet conveying device showing an embodiment of the present invention.

FIG. 2 is a longitudinal side view showing an example of an image forming apparatus to which the present invention is applied.

FIG. 3 is a front view of the paper feed deck section.

FIG. 4 is a rear view of the paper feed deck section.

FIG. 5 is a side view of the paper feed deck.

FIG. 6 is a side view of the lock portion of the paper feed deck.

FIG. 7 is a flowchart also related to the present invention.

FIG. 8 is a circuit diagram of a lifter motor showing a second embodiment of the present invention.

FIG. 9 is a current change diagram of the lifter motor.

FIG. 10 is a longitudinal sectional side view of a paper feed deck section of a conventional sheet conveying device.

[Explanation of symbols]

P Sheet G Gap between female coupling and male coupling 1 Image forming device 2 Paper feed deck 3 Lifter plate 4 Machine main body side 5, 6 Drive system (wire) on lifter plate 3 side 7
Coupling female 7a Engagement hole 9 Coupling 9a Claw portion 10 Coupling unit 20
Lifter motor 40 lock unit

Claims (1)

[Claims] Claim 1: A front-loading paper feed deck that is attached to the image forming apparatus so that stacked sheets can be fed to the image forming apparatus, and that can be taken in and out from the machine main body on the operating side; and the paper feed deck. A sheet feeding device that has a lifter plate that is vertically movable in a deck and on which sheets are loaded, the lifter plate being driven by a drive source provided on the machine body side; A coupling pair is a coupling means for coupling a drive source and a drive system for the lifter plate on the sheet feeding deck side, and when the coupling pair is released, the male side and the female side of the coupling pair are connected. A paper feeding device characterized by providing a gap between the two sides.