JPH0427875Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a supply device for electric copying machines, printers, and the like.

Prior Art Paper feeding devices for electronic copiers, printers, etc. rotate multiple gears by driving a motor.
It is known that the bottom plate of the paper feed tray is raised and lowered by engaging an engagement pin that rotates as these gears rotate with a bottom plate lift lever that moves the bottom plate of the paper feed tray up and down.

However, in conventional paper feeding devices, the engagement pin is implanted in one of the gears, so it is necessary to accurately control the amount of rotation of this gear. Not only is this complicated, but there is also a drawback that when the motor becomes uncontrollable, the engagement pin overruns and collides with the bottom plate lifting lever.

Purpose The purpose of the present invention is to provide a paper feed device that can simplify the lowering control means of the bottom plate of the paper feed tray and can prevent secondary troubles caused by poor control of raising and lowering the bottom plate. There is a particular thing.

Configuration The present invention is a paper feeding device that raises and lowers the bottom plate by transmitting the rotational force of a bottom plate lifting motor capable of forward and reverse rotation to the bottom plate of a paper feed tray using a predetermined transmission means, and the present invention transmits the forward and reverse rotation of the bottom plate lifting motor. A rotating plate is pivotally mounted via a unidirectional clutch that transmits only the rotation in the direction of raising the bottom plate of the rotation transmitting means for moving the bottom plate, and the bottom plate lifting member is moved by an engagement pin that rotates together with the rotating plate. The bottom plate is raised and lowered through the base plate.

Hereinafter, a specific example of the configuration of the present invention will be described in detail based on the drawings.

In FIG. 1, a static eliminator 4, a cleaning device 5, a charging device 6, an exposure device 7, and a developing device 8 are provided on the circumferential surface of a band-shaped photoreceptor 3 that is rotationally driven by a pair of rollers 1 and 2. A toner image of image information is formed by a predetermined image forming process using an image forming apparatus. While this image forming process is being executed, the paper p accommodated in the paper feed tray 10 disposed in the printer main body 9 (if the printer has multiple paper feed trays as in the illustrated example, Either one of the sheets) is moved to a predetermined position by a sheet feeding means consisting of a bottom plate lifting arm 12 for pushing up the bottom plate 11 of the sheet P, a pre-feed roller 13, a feed roller 14, a separation roller 15, and a squeeze roller 16. It has been delivered and is waiting. This waiting paper p is fed again at the timing when the leading edge of the toner image formed on the photoreceptor 3 at the leading edge matches, and after passing through the transfer device 17 and the fixing device 18, the image is recorded, and then the sheet is guided 19, and is discharged onto a paper discharge tray 21 by a paper discharge roller 20.

As shown in FIGS. 2 to 4, the bottom plate lifting arm 12 is connected to a pair of side plates 9 of the printer main body 9.
A (one not shown) is fixed with a screw 23 to a shaft 22 rotatably suspended horizontally.

When the paper feed tray 10 is attached to the printer main body 9 along the guide 24 fixed to the side plate 9a with the tray cover 10a of the paper feed tray 10 closed, the tray cover opening/closing detection means 25 is turned ON (fourth (see figure).

When the tray cover opening/closing detection means 25 is turned on, the bottom plate lifting motor 26 rotates forward, and the first gear 28, second gear 29, third gear 30, which mesh with the worm gear 27 of the bottom plate lifting motor 26 and rotate in communication with each other. The fourth gear 31 and the fifth gear 32 are respectively indicated by arrows a1 and a2 indicated by solid lines in FIG.
Start rotating in direction a3. The first gear 28 and the second gear 29 and the third gear 30 and the fourth gear 31
are formed coaxially and integrally, and the side plate 9
They are rotatably connected by respective support shafts 34 and 35 implanted in a. Further, the fifth gear 32 is fixed to a slide shaft 36, and the side plate 9
A slide shaft 36 is slidably supported by a bearing 37 fixed to the third side plate 9b and the other side plate 9b.
By sliding in the vertical direction in the figure, it is configured to slide while remaining engaged with the fourth gear 31.

Note that the end 3 of the slide shaft 36 on the side plate 9b
6a is opposed to the first bent edge 38a of the interlocking plate 38. This interlocking plate 38 has a first bent edge 38
A rightward turning behavior is imparted around the support shaft 40 in FIG. 3 by the pressing force of a pressing coil spring 39 installed between the guide 24 and the guide 24. When the paper feed tray 10 is not attached to the printer main body 9, the sliding shaft 36 is moved between the fifth gear 32 and the side plate 9a by the pressing force of the coil spring 39.
It is moved downward in FIG. 3 against the pressing force of another coil spring 41 wound between.
The fifth gear 32, which is integral with the slide shaft 36, has also been moved downward in FIG. Here, the coil spring 39
The pressing force of the coil spring 41 is set to be larger than the pressing force of the other coil springs 41.

A rotary plate 42 is pivotally mounted on the slide shaft 36 via a one-way clutch 43. This one-way clutch 43 includes a collar 43a fixed to the slide shaft 36, as shown in FIG.
A ball 43b is inserted between the rotary plate 42 and a ratchet claw-shaped notch 42a formed in the inner circumferential surface of the rotary plate 42. This one-way clutch 43 is
In FIG. 2, when the fifth gear 32 rotates in the direction of arrow ^a3 , the ball 43b is locked between the collar 43a and the notch 42a, transmitting the rotation of the fifth gear 32 to the rotary plate 42, and transmitting the rotation of the fifth gear 32 to the rotating plate 42. When the gear 32 rotates in ^{the three} directions of arrow b, the ball 43b moves to the collar 43a.
and the notch 42a, and the fifth gear 3
The transmission of rotation by rotation plate 2 to rotation plate 42 is cut off.

An engagement pin 42b is formed on the side surface of the rotary plate 42 facing the paper feed tray 10. When the paper feed tray 10 is not attached to the printer main body 9 as described above, the rotation trajectory of the engagement pin 42b is determined by the bottom plate as a bottom plate elevating member for swinging the bottom plate elevating arm 12 via the shaft 22. It faces a position away from the swinging path of the lift lever 44.

By the way, when the paper feed tray 10 is mounted with the tray cover 10a of the paper feed tray 10 closed, the guide 24 in the mounting/detaching path of the paper feed tray 10, prior to the rotation of the gears 28 to 32 described above, The second bent edge 38b of the interlocking plate 38 extending from the side is pushed to the left in FIG. 3 by the guide piece 10b formed on the side of the paper feed tray 10. As a result, the interlocking plate 38 rotates to the left around the support shaft 40 against the pressing force of the coil spring 39.
The first bent edge 38a is the end 3 of the slide shaft 36.
Leave 6a.

The slide shaft 36, which is no longer restrained by the first bent edge 38a, moves upward in FIG. 3 due to the pressing force of the other coil spring 41. The amount of movement l of the slide shaft 36 at this time is
The orbit of the engagement pin 42b of the rotary plate 42, which moves together with the rotary plate 42, is set to extend into the swing path of the bottom plate elevating lever 44. Therefore, when the gears 28 to 32 rotate in the directions of arrows a ¹ , a ² , and a ³ in this state, the rotating plate 42 engages the unidirectional clutch 43
Rotate through. As a result, the engagement pin 42b
turns to the right in Fig. 2, and the bottom plate lift lever 44
against its own weight and turns to the left along with the shaft 22 (arrow
a Swing in ⁴ directions). This bottom plate lifting lever 44
As the bottom plate lift arm 12 integrated with the shaft 22 moves up and down the bottom plate 11, the paper p loaded on the bottom plate 11 comes into contact with the circumferential surface of the prefeed roller 13. Thereafter, the paper p is fed one by one from the paper feed tray 10 by operating the paper feed means described above.

Note that, as shown in FIG. 4, for example, a paper presence/absence detection means 45 for detecting the presence or absence of paper p stacked on the bottom plate 11 is arranged in the paper feed section of the printer main body 9. The paper presence/absence detection means 45 includes a light emitting element 45a and a light receiving element 45b, and detects a detection mark 46 written on the bottom plate 11, which is exposed when the last paper p on the bottom plate 11 is delivered, for example. By doing so, the presence or absence of paper p is detected. This paper presence detection means 45
The detection result is displayed by a paper non-display means (not shown), which includes a light emitting diode or the like, provided on the operation panel of the printer main body 9.

Here, the paper non-display means displays that there is no paper p, or detects that the paper p is running low, and in order to replenish new paper p,
The operator closes the tray cover 1 of the paper feed tray 10.
When you open 0a, the paper feed tray 10 is installed.
Tray cover opening/closing detection means 25 that was ON
turns off. Tray cover opening/closing detection means 25
When is turned OFF, the bottom plate lifting motor 26 rotates in the reverse direction, and the gears 28 to 32 rotate in the directions of arrows b ₁ , b ₂ , and b ₃ shown by chain lines in FIG. By this rotation of the fifth gear 32 in the direction of arrow _b3 , the rotational transmission force of the one-way clutch 43 to the rotary plate 42 is cut off, and the bottom plate lift lever 44 engaged with the engagement pin 42b is moved from the bottom plate. 11, etc., the rotary plate 42 swings in the direction of arrow _b4 while rotating following the fifth gear 32 via the engagement pin 42b. As the bottom plate lift lever 44 swings in the direction of arrow ^b4 , the bottom plate 11 is lowered via the shaft 22 and the bottom plate lift arm, making it possible to replenish new paper p.

As is clear here, due to the weight of the bottom plate 11, etc., the bottom plate lifting lever 44 and the engagement pin 42b
Due to the action of the one-way clutch 43, the rotary plate 42, which rotates via the unidirectional clutch 43, is not restricted by the rotation of the fifth gear 32, that is, by the operation of the bottom plate lifting motor 26. Thereby, the rotation of the rotary plate 42 can be stopped regardless of whether or not the fifth gear 32 is rotating when the bottom plate 11 is lowered to the lowered position shown by the solid line in FIG. Therefore, it is not necessary to control the stop of the bottom plate lift motor 26 at the bottom plate lowered position so strictly, and the control means thereof is simplified (for example, it can be controlled only by a timer).
Moreover, even if the fifth gear 32 overruns, no problem occurs.

Note that the stop control of the bottom plate lift motor 26 at the raised position of the bottom plate 11 is performed by a bottom plate rise detection means 47 for detecting that the bottom plate 11 has been raised to the raised position (paper feeding position), as shown in FIG. 4, for example.
It is done through.

Effects According to the present invention, a unidirectional clutch is provided that transmits the rotational force of the motor for raising and lowering the bottom plate to the rotary plate only when the paper feed tray rotates forward in the direction of raising the bottom plate. During lowering, the rotating plate remains in its position as soon as the bottom plate finishes lowering.

Therefore, even if the bottom plate elevating motor continues to rotate somewhat after the bottom plate has finished lowering, the engagement pin remains stopped together with the bottom plate elevating member.
The subsequent raising of the bottom plate by means of the engagement pin takes place via the one-way clutch simultaneously with the rotation of the bottom plate lifting motor. By providing a one-way clutch in this way, the engagement pin for raising the bottom plate is always in contact with the bottom plate lifting member at the beginning, without having to strictly control the stop timing of the bottom plate lifting motor when the bottom plate is lowered. Therefore, the bottom plate can be quickly raised simultaneously with the rotation of the bottom plate lifting motor.

Furthermore, since the bottom plate is lowered by reversing the bottom plate lifting motor while the bottom plate lifting member follows the engagement pin, sudden lowering of the bottom plate is prevented, which has the effect of preventing noise and impact caused by the lowering of the bottom plate. play.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a printer having a paper feeding device of the present invention, FIG. 2 is a side view of the main parts of the paper feeding section of the printer, and FIG. 3 is a partially cutaway plan view and a partially cutaway plan view of the paper feeding section of the printer. FIG. 4 is an explanatory diagram of the operation of the paper feeding section. 10... Paper feed tray, 11... Bottom plate, 26...
Bottom plate lifting motor, 42... Rotating plate, 43... Unidirectional clutch, 44... Bottom plate lifting member.

Claims (1)

[Scope of Claim for Utility Model Registration] In a paper feeding device that feeds paper from a paper feeding tray having a bottom plate that can be raised and lowered to place paper, the bottom surface of the bottom plate raises and lowers the bottom plate by swinging in the vertical direction. a bottom plate elevating member having a bottom plate elevating arm that abuts on the bottom plate elevating arm; and an engaging pin that abuts on the bottom plate elevating member;
A rotary plate that rotates to swing the bottom plate elevating member using the engagement pin; a motor for lifting and lowering the bottom plate that is rotatable in forward and reverse directions; and a rotation transmission means for transmitting the rotational force of the motor to the rotary plate. and a one-way clutch provided on the rotary plate that transmits only the rotation of the motor in the direction of raising the bottom plate to the rotary plate via the rotation transmission means.