JP3385822B2 - Paper feeder rotation control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device used in an image forming apparatus such as a copying machine or a printer, and more particularly to improvement of a rotation control device for controlling the rotation of the sheet feeding device.

[0002]

2. Description of the Related Art Generally, a sheet feeding device for feeding sheet-like recording sheets as recording media one by one is provided in an image forming apparatus such as a copying machine or a laser pudding.

This paper feeding device generally comprises a paper feeding roll arranged on a paper tray, and has a structure in which the paper feeding roll is rotated once to feed the paper to a downstream paper conveying roller.

On the other hand, there is a conventional one using a one-way clutch as a rotation control device for rotating the paper feed roll exactly once. However, in the case where this one-way clutch is used, the rotation stop angle of the paper feed roll varies, and the rotation stop position of the paper feed roll is not accurate. In addition, the one-way clutch used had problems such as abnormal noise.

In order to solve the above-mentioned problems, conventionally, a rotation control device using a toothless gear has been proposed as a rotation control device for a paper feed roll (Shokai 61-1418).
No. 53, Japanese Examined Patent Publication No. 2-193830).

A conventional rotation control device 1 using this toothless gear has a paper feed roll 2 having a substantially D-shaped cross section fixed at one end, as shown in FIG. 11 and FIG. 12 showing its conceptual side view. As shown in FIG. 12, the roll drive shaft 3 and the tooth-chipped gear 4 fixed to the other end of the paper feed roll drive shaft 3 and the drive gear 5 for transmitting power to the tooth-chipped gear 4 are provided. When the toothless portion 4a of the gear 4 faces the drive gear 5, the power transmission of the drive gear 5 is cut off.

Further, the conventional rotation control device 1 will be described in more detail.
And the stopper cam 6 coaxially with the toothless gear 5 adjacent to
Is stuck. Then, when the hook 8 of the solenoid 7 is engaged with the engaging portion 6a of the stopper cam 6, as shown in FIG.
As described above, the drive gear 5 and the tooth-chipped portion 4a of the tooth-chipped gear 4 face each other and the power transmission of the drive gear 5 is blocked.

On the other hand, when the solenoid 7 is turned on and the engagement between the engaging portion 6a of the stopper cam 6 and the hook 8 of the solenoid 7 is released, the pin 4 protruding laterally from the tooth-chipped gear 4 is released.
The tooth-chipped gear 4 is rotated in one direction (clockwise direction) by the biasing force of the coil spring 9 that engages with b and biases the tooth-chipped gear 4 in one direction (clockwise in FIG. 12). 5 and the tooth-chipped gear 4 mesh with each other, the driving force of the drive gear 5 is transmitted to the tooth-chipped gear 4, and the paper feed roll 2 is further moved in one direction (clockwise in the figure) via the paper feed roll drive shaft 3. To start rotating.

On the other hand, when the solenoid 7 is turned on to release the engagement between the engaging portion 6a of the stopper cam 6 and the hook 8 of the solenoid 7, the solenoid 7 is immediately turned off. The hook 8 of 7 maintains the posture in a state of being in contact with the peripheral surface of the stopper cam 6. When the paper feed roll 2 makes one revolution, the engaging portion 6a of the stopper cam 6 and the hook 8 of the solenoid 7 are engaged again, and at the same time, as shown in FIG.
The tooth-missing portion 4a of the drive gear 5 opposes to cut off the power transmission of the drive gear 5.

In FIGS. 11 and 12, reference numeral 10 is a sheet stacking plate for stacking and accommodating sheet-like recording sheets 11, and the sheet stacking plate 10 is urged by a biasing spring 12 disposed below the sheet stacking plate 10. It is always urged upward, that is, toward the paper feed roller 2 side. In FIGS. 11 and 12, reference numeral 13 is a cam for releasing the urging force of the sheet stacking plate 10 fixed to the paper feed roll drive shaft 3, and as shown in FIG. 11, the urging force releasing cam 13 is for the sheet stacking plate 10. It engages with a pin 10a protruding laterally, thereby pushing down the sheet stacking plate 10 against the urging force of the urging spring 12, and releasing the pressure contact between the recording paper 11 and the paper feed roller 2. is doing. Of course, the bias release cam 13 rotates together with the paper feed roller 2, and when the engagement between the bias release cam 13 and the pin 10a is released, the sheet stacking plate 10 is moved upward by the bias force of the bias spring 12. In this structure, the uppermost surface of the recording paper 11 stacked and accommodated on the paper stacking plate 10 is brought into pressure contact with the peripheral surface of the paper feed roller 2 to start feeding the recording paper 11.

In FIGS. 11 and 12, reference numeral 14 is a bearing that supports the paper feed roll drive shaft 3, and 15 is a housing that supports the bearing 14.

[0012]

By the way, according to the rotation control device 1 for the paper feed roller described above, the urging of the paper stacking plate 10 against the paper feed roller 2 and the release thereof are fixed to the paper feed roll drive shaft 3. Since it is performed via the urging force releasing cam 13, the upward urging force of the urging spring 12 is applied to the pin 10a.
And is transmitted to the paper feed roll drive shaft 3 via the bias release cam 13, which increases the sliding resistance between the paper feed roll drive shaft 3 and the bearing 14 supporting the same. The biasing force of the coil spring 9 that biases the tooth-chipped gear 4 in one direction is not smoothly transmitted to the tooth-chipped gear 4, which may cause rotation failure of the sheet feed roll 2.

In order to avoid this possibility, it is conceivable that the biasing force of the coil spring 9 is increased. Then, the engagement between the engaging portion 6a of the stopper cam 6 and the hook 8 of the solenoid 7 will be taken this time. If the suction force of the solenoid 7 is insufficient, the engagement between the engagement portion 6a of the stopper cam 6 and the hook 8 of the solenoid 7 may not be released. Solenoid 7 to counter it
It is conceivable that the capacity of the solenoid 7 is increased to increase the suction force of the solenoid 7, but then the size of the solenoid 7 is increased and the size and manufacturing cost of the rotation control device 1 are increased. There is a problem that it is difficult to achieve miniaturization of an image forming apparatus such as a printer that uses the apparatus.

The present invention has been made in view of the above-mentioned circumstances, and is small in size, and has stable rotation of the paper feed roll.
An object of the present invention is to provide a rotation control device for a sheet feeding device that performs the reliable rotation control.

[0015]

In order to solve the above-mentioned problems, according to the present invention, in a rotation control device of a sheet feeding device which rotates a sheet feeding roll once to feed sheet-like recording sheets one by one, one end is fed. A paper roll is independently and non-rotatably supported, and a first toothless gear is independently and non-rotatably supported at the other end, and between the first toothless gear and the paper feed roll. The paper feed roll drive shaft that independently supports the first stopper cam so that it cannot rotate, the first hook that engages with the engaging portion of the first stopper cam, and the first tooth-chipped gear. A second toothless gear adjacently rotatably supported by the paper feeding roll drive shaft, and rotatably supported by the paper feeding roll drive shaft adjacent to the second toothless gear, and A second stopper cam that rotates integrally with the second toothless gear; The engagement release cam that is rotatably supported by the paper feed roll drive shaft adjacent to the stopper cam and that rotates integrally with the second stopper cam, and the engagement portion of the second stopper cam. A second hook that fits together, a first biasing means that biases the first toothless gear in the rotational direction, and a second biasing means that biases the second toothless gear in the rotational direction. And a hook separating means for separating the first hook from the engaging portion of the first stopper cam by rotation of the engagement releasing cam, the first tooth-missing gear and the second tooth-missing gear. A drive gear is provided which meshes with each other and rotates the first toothless gear and the second toothless gear in one direction.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION As a first hook that engages with an engaging portion of the first stopper cam, a rotatable engaging claw that is always biased toward the cam face side of the first stopper cam is used. It is used.

As the second hook that engages with the engaging portion of the second stopper cam, an engaging claw that can be engaged and disengaged by a solenoid is used.

A torsion spring, a compression coil spring, or a tension coil spring is used as the second urging means for urging the second toothless gear in the rotational direction, and one end of the spring is the second spring. It engages with a toothless gear, a second stopper cam, or a disengagement cam, and the other end has the first stopper cam, the first toothless gear, the paper feed roll drive shaft, and a paper feed roll. Used to engage either of the.

As the hook separating means for separating the first hook from the engaging portion of the first stopper cam by the rotation of the engagement releasing cam, a plate material formed integrally with the first hook is used. .

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rotation control device for a sheet feeding device according to the present invention will be described in detail below, but before that, an image forming apparatus 1 to which the rotation control device of the present invention is applied will be described.

FIG. 1 is a conceptual diagram of an image forming apparatus 1 to which the rotation control device of the present invention is applied. This image forming apparatus 1
Is an apparatus main body 2, a paper discharge section 3 which is detachably attached to the right side of the apparatus main body 2, and is detachably attached to the bottom of the apparatus main body 2 so as to reverse the advancing direction of the sheet so that its upper and lower surfaces are A switchback unit 4 for reversing, and a second paper cassette 5 that is detachably attached to the bottom surface of the switchback unit 4 and that stores a larger number of sheets (for example, about 500 sheets) than a normal paper cassette. Has been done.

The above-described paper discharging unit 3, switchback unit 4, and second paper cassette 5 are prepared as optional units that can be added to the outside of the apparatus main body 2, and among them, the paper discharging unit 3 and the switch. The back section 4 is an image forming process that is normally performed only by the apparatus main body 2,
That is, it is not used when an image is formed on only one side of the sheet-like recording paper.

On the other hand, in the apparatus main body 2, an optical unit 6 for outputting a laser beam containing image information and a photoconductor 7 are provided.
An electrostatic recording type image forming unit 8 composed of the above, a fixing unit 10 composed of a fixing roller 9 and the like, main constituent elements constituting the electrostatic recording system, etc. are arranged, and a sheet is provided at the bottom thereof. A first paper cassette 12 accommodating and accommodating the state recording paper 11 is detachably mounted in the direction of arrow A.

In FIG. 1, reference numeral 13 is a foldable manual feed tray used in the manual feed mode, 14 is a tray cover for covering the manual feed tray 13 when the manual feed tray 13 is stored, and 15 is a main body 2 of the apparatus. A main tray cover that covers the main tray 16 formed on the upper surface, and a sub tray 17 that is disposed on the side of the paper discharge unit 3.

Next, the operation of the image forming apparatus 1 described above will be briefly described.

First, the image forming process in the single-sided recording mode in which the image is formed only on one side surface of the sheet-shaped recording paper will be described.

When one sheet of recording paper 11 is fed by the feed roller 20 from the uppermost surface of the first paper cassette 12, the recording paper 11 follows the first and second paper guide chutes 21 and 22 and the image forming means 8 is formed. The image forming means 8 forms an image on one side of the recording sheet. In addition, in the middle of the first and second sheet guide chutes 21 and 22 described above, the conveyance rollers 23 and 24 and the registration roller 25 that takes the conveyance timing of the recording sheets separated one by one from the manual feed tray 13 in the manual feed mode.
Is intervening.

When an image is formed on one side of the recording paper by the image forming means 8, the recording paper is then conveyed to the fixing means 10 via the third paper guide chute 26, and the unfixed image is formed there. It is fixed. After the image is fixed,
The recording paper on which an image is formed on one side is next discharged onto the discharge roller 2.
Through the fourth or fifth sheet guide chute 28,
It is discharged to one of the paper guide chutes out of 29.

At the base ends of the fourth or fifth paper guide chutes 28, 29, the recording paper discharged from the discharge roller 27 is attached to the fourth or fifth paper guide chutes 28, 29.
A first switching claw 30 that guides to either one of the two is disposed, and when the first switching claw 30 rotates counterclockwise and stops positioning at that position, the discharge roller 27
The recording paper discharged from is guided to the fourth paper guide chute 28. The recording paper guided to the fourth paper guide chute 28 is ejected onto the main tray 16 via the ejection roller 31.

On the other hand, when the above-mentioned first switching claw 30 is rotated clockwise and positioned at that position, the recording paper discharged from the discharge roller 27 is transferred to the fifth paper guide chute 2.
You will be guided to 9. The recording sheet guided to the fifth sheet guide chute 29 is then guided to the sixth or seventh sheet guide chute 32, 33 via the second switching claw 31, but in the single-sided recording mode, The second switching claw 31 always rotates counterclockwise and is positioned at that position, so that the recording paper on which an image is formed on one side is ejected from the discharge roller 3.
It is discharged onto the sub-tray 17 via 4 and is loaded and stored therein.

Similarly, in the image forming process in the single-sided recording mode, when one sheet of recording paper 11 is fed from the uppermost surface of the second paper cassette 5 by the feed roller 35, the recording paper is next moved to the eighth paper guide chute. 36, a ninth paper guide chute 37 connected to the eighth paper guide chute 36, a tenth paper guide chute 38 connected to the ninth paper guide chute 37, and a tenth paper guide chute 38.
The first and second sheet guide chutes 21 and 22 connected to the sheet guide chute 38 are conveyed to the image forming means 8, and the image forming means 8 forms an image on one side of the recording sheet. Become.

The recording paper on one side of which the image is formed is thereafter discharged to either the main tray 16 or the sub-tray 17, like the recording paper in the single-sided recording mode described above. Note that the sheet conveying rollers 39 and 40 are also interposed in the middle of the above-mentioned eighth and ninth sheet guide chutes 36 and 37.

Also in the manual feed mode in the single-sided recording mode, the recording papers stacked and accommodated on the manual feed tray 13 are separated one by one by a separation roller (not shown) and guided to the eleventh paper guide chute 13a. afterwards,
The transfer timing is adjusted by the registration roller 25, and the second
The sheet is conveyed to the paper guide chute 22 of the main tray 1 and is then transferred to the main tray 1 similarly to the recording paper in the single-sided recording mode described above.
6 or the sub tray 17 is discharged.

Next, the image forming process in the double-sided recording mode for forming images on both sides of the recording paper will be described.

The recording paper, which is fed from the first paper cassette 12 by the feed roller 20, has an image formed on one side by the image forming means 8 and has the image fixed by the fixing means 10, passes through the discharge roller 27 and the paper discharge section. When the second switching claw 31 is guided to the inside of the third position, the second switching claw 31 is rotated clockwise by a predetermined angle and stopped at that position, so that the recording paper on which an image is formed only on one side is moved to the seventh position. Guide to the paper guide chute 33.

The recording paper guided in the seventh paper discharge chute 33 is guided to the switchback section 4 from the downstream end of the seventh paper discharge chute 33.

On the other hand, the switchback unit 4 is rotatable in the reverse direction in which the first holding chute 41 on which an image is formed on one side and which temporarily holds the recording paper is reversed, and which reverses the traveling direction of the temporarily held recording paper. Switch back roller 42
The recording paper, which has the reverse direction of travel and is reversed, is again transferred to the image forming means 8 of the apparatus main body 2 via the second holding chute 43 provided on the lower surface side of the first holding chute 41. It is structured to be guided.

On the other hand, a third switching claw 44 is provided at the terminal end of the seventh paper discharge chute 33. The third switching claw 44 rotates counterclockwise and, when stopped at that position, guides the recording sheet guided through the seventh sheet discharging chute 33 to the first holding chute 41,
When it rotates clockwise again and stops at that position, the first
After switching back the recording paper guided to the holding chute 41, the recording paper is guided to the second holding chute 43 via the twelfth paper guiding chute 45.

Paper transport rollers 46, 47, 48 for transporting the paper are also interposed in the twelfth paper guide chute 45 and the second holding chute 43.

Therefore, the recording paper guided to the switchback unit 4 by the seventh paper guiding chute 33 is temporarily guided to the first holding chute 41 side by the third switching claw 44, and further rotates in the forward direction. The whole is temporarily accommodated in the first holding chute 41 by 42.
The switchback roller 42 maintains the posture of gripping the trailing edge of the recording paper guided in the first holding chute 41 even when the recording paper is temporarily held.

Next, the recording paper is the first holding chute 41.
When it is detected that the third switching claw 44 is temporarily held in the inside, the third switching claw 44 rotates clockwise by a predetermined rotation angle and stops,
When the upstream side of the second paper guide chute 45 is expanded, the switchback roller 42 is reversely rotated, and this time, the rear end of the recording paper temporarily held in the first holding chute 41 is conveyed first, and the twelfth The recording sheet is guided to the second holding chute 43 through the sheet guiding chute 45 of No. 2.

The recording paper guided in the second holding chute 43 is conveyed to the ninth paper guide chute 37 via the curved thirteenth paper guide chute 49, and further the tenth paper guide. It is guided again to the first paper guide chute 21 in the apparatus main body 2 via the chute 38.

As described above, since the recording sheet conveyed again to the image forming means 8 through the second holding chute 43 of the switchback section 4 is turned upside down, this time the recording sheet is conveyed by the image forming means 8. An image is formed on the other side surface, and the image is further conveyed to the fixing unit 10, where the image on the other side surface is fixed. After that, the recording paper on which images are formed on both sides is discharged to either one of the main tray 16 and the sub-tray 17 via the discharge roller 27 and the first switching claw 30.

In the double-sided recording mode, both the recording sheets separated from the manual feeding tray 13 one by one in the manual feeding mode and the recording sheets separated and conveyed one by one from the second sheet tray 5 are processed as described above. An image is formed on both sides of the paper through the same process as the above.

On the other hand, as shown in FIG. 2 which is an enlarged partial cutaway view of FIG. 1, an apparatus main body 2 which constitutes the above-mentioned image forming apparatus 1
At the tip of the manual feed tray 13, there is provided a paper feed device 50 having a rotation control device according to the present invention, which separates and conveys the recording papers stacked and accommodated on the manual feed tray 13. ing.

FIG. 3 is an exploded perspective view of the above-described sheet feeding device 50.

The paper feeding device 50 has a substantially D-shaped cross section and has a D-shaped cross-section insertion hole 51 at the center thereof.
a sheet feed roll 51 on which a is formed, and this sheet feed roll 51
And a rotation control device 53 according to the present invention at the left end of the paper feed roll drive shaft 52. The paper feed roll drive shaft 52 has a D-shaped cross section.
Is provided.

The rotation control device 53 is independent of a first stopper cam 54 integrally formed at an intermediate portion of a paper feed roll drive shaft 52 (hereinafter simply referred to as a drive shaft) and a left end portion of the drive shaft 52. And a first tooth-missing gear 55 that is non-rotatably supported. As shown in the drawing, a fitting insertion hole 55a having a D-shaped cross section is formed at the center of the first tooth-chipped gear 55, and a cross section D is formed in the fitting insertion hole 54a.
Since the V-shaped drive shaft 52 is inserted, the first tooth-missing gear 5
4 is independently supported by the drive shaft 52 so as not to rotate.

On the other hand, an engaging portion 54a consisting of a step-like projection is formed on the peripheral surface of the first stopper cam 54, and the engaging portion 54a is provided at a position adjacent to the first stopper cam 54. A first hook 56 that engages with the first stopper cam 54 to prevent the rotation of the first stopper cam 54 is provided.

The first hook 56 is composed of a tongue piece 57 rotatably supported about a shaft (not shown), and an engaging claw 57a is formed by bending at the tip right side of the tongue piece 57. Specifically, the engaging claw 57a is detachably engaged with the engaging portion 54a of the first stopper cam 54. The first hook 5 including the tongue piece 57
6 is always urged toward the peripheral surface side of the first stopper cam 54 by the urging force of the coil spring 58 arranged on the back surface thereof.

On the other hand, a second toothless gear 59 is rotatably supported on the drive shaft 52 at a position adjacent to the first toothless gear 55, and this is also rotatably supported by the drive shaft 52. A second stopper cam 60 that rotates integrally with the second toothless gear is supported on the drive shaft 52 adjacent to the second toothless gear 59, and the drive shaft 52 adjacent to the second stopper cam is further supported. The second stopper cam 6
An engagement release cam 61 that rotates together with 0 is supported.

On the other hand, an engaging portion 60a consisting of a step-shaped projection is formed on the peripheral surface of the second stopper cam 60, and the engaging portion 60a is located adjacent to the second stopper cam 60. A second hook 62 is provided which is engaged with 60a and blocks the rotation of the second stopper cam 60.

The second hook 62 has a solenoid 63.
When the solenoid 63 is turned off, a return spring 65 disposed on the back surface of the solenoid 63 is attached to the engagement portion 60a of the second stopper cam 60. Engaging claw 6 due to power
Reference numeral 4 presses against the peripheral surface of the second stopper cam 60 and engages with the engaging portion 60a of the second stopper cam 60 to stop its rotation.

On the other hand, on the respective sides of the above-described second tooth-chipped gear 59, the second stopper cam 60, and the engagement release cam 61, guide holes 59b having the same shape concentrically with the rotation center,
60b and 61b are formed, and the guide holes 59b and 60 are formed.
Engaging pins 66 projecting laterally from the first stopper cam 54 are fitted and inserted in b and 61b, and the second tooth-chipped gear 59 and the second stopper cam 60 are inserted. , And the rotation of the disengagement cam 61 with respect to the drive shaft 52 by a predetermined rotation angle or more.

On the other hand, a pin 55b is formed on the lateral side of the first tooth-chipped gear 55, and the pin 55b is provided with a first pinch-gear gear 55 that urges the first tooth-chipped gear 55 clockwise in the drawing. Urging means 67 is provided. The first biasing means 67 is a tension coil spring 68 in the embodiment.
It is composed by.

Further, a pin 59c is formed to project laterally from the second tooth-chipped gear 59, and the tip of an engaging pin 66 projecting laterally from the pin 59c and the first stopper cam 54. The second urging means 69 is disposed between and. The second urging means 69 is composed of a tension coil spring 70 in the embodiment, but the second urging means 69 may be composed of a torsion spring or a compression coil spring, or in the embodiment. One end of the tension coil spring 70 is engaged with the second tooth-chipped gear 59 and the other end is engaged with the first stopper cam 54. However, one end of the tension coil spring 70 is engaged with the second stopper cam 6.
0, or engage with the engagement release cam 61,
Further, the other end may be engaged with any of the first tooth-chipped gear 55, the drive shaft 52, and the paper feed roll 51.

On the other hand, the first hook 56 is provided with a hook separating means 71 for separating the first hook 56 from the engaging portion 54a of the first stopper cam 54 by rotating the engagement releasing cam 61. It is set up. The hook separating means 71 is composed of a left front surface portion 57b of a plate-shaped tongue piece 57 which constitutes the first hook 56, and the left front surface portion 57b of the tongue piece 57 has a top portion of the disengagement cam 61. 61a
When pressure is applied to the tongue piece 57, the tongue piece 57 rotates clockwise against the biasing force of the coil spring 58 to release the engagement between the engaging claw 57a of the tongue piece 57 and the engaging portion 54a of the first stopper cam 54. .

Incidentally, reference numeral 72 in FIG. 3 denotes a cam for releasing the biasing force of a sheet stacking plate, which will be described later, which is independently supported by the drive shaft 52 so as not to rotate.

On the other hand, the rotation control device 53 of the sheet feeding device 50 is compactly assembled on the left side of the sheet feeding device 50 as shown in FIG. 4 which is a front view after the assembly.

In FIG. 4, reference numeral 73 is a sheet stacking plate for stacking and storing sheet-shaped recording sheets 74.
Is always urged upward, that is, toward the paper feed roller 51 side by the urging force of the urging spring 75 disposed below it. Further, the urging force releasing cam 72 engages with a pin 73a protruding laterally of the sheet stacking plate 73, thereby pushing down the sheet stacking plate 73 against the urging force of the urging spring 75, The pressure contact between the recording paper 74 and the paper feed roller 51 is released. Of course, the bias release cam 72 rotates together with the sheet feeding roller 51, and the bias release cam 72 and the pin 7
When the engagement with 3a is released, the sheet stacking plate 73 is moved upward by the urging force of the urging spring 75, and the sheet stacking plate 7 is moved.
The uppermost surface of the recording papers 74 stacked and accommodated in the sheet feeding roller 5
The recording sheet 74 starts to be fed by being pressed against the peripheral surface of the recording sheet 1. In FIG. 4, reference numeral 76 is a bearing that supports the feed / drive shaft 52, 77 is a housing that supports the bearing 76, and 78 is a first bearing.
And a drive gear that meshes with the second toothless gears 55 and 59.

In FIG. 4, reference numeral 90 designates a resin core fixed to both sides of the paper feed roll 51, and this resin core 90 regulates the number of recording papers 74 to be loaded and loaded on the paper loading plate 73. Is.

In the embodiment, the second tooth-chipped gear 59, the second stopper cam 60, and the engagement release cam 61 are made of synthetic resin or the like, as shown in FIG. 5 which is a conceptual cross-sectional view of FIG. It is integrally formed.

Next, the operation of the above-described rotation control device 53 will be described, and the structure will be described in more detail.

FIG. 6 is an enlarged left side view of a part of FIG. 4, particularly showing the initial position of the rotation control device 53.

At the initial position of the rotation control device 53, the first hook 56 rotates counterclockwise about the shaft 80 by the urging force of the coil spring 58, and its engaging claw 57a.
Engages with the engaging portion 54a of the first stopper cam 54 to regulate the rotation of the first stopper cam 54.

Further, since the solenoid 63 is OFF, the second hook 62 also rotates clockwise around the fulcrum 81 by the urging force of the coil spring 65, and the engagement claw 64 thereof engages with the second stopper cam 60. Engaging the part 60a,
The rotation of the second stopper cam 60 is restricted.

Thus, the first and second hooks 5
6 and 62 are first and second stopper cams 54 and 60, respectively.
In the state of being engaged with the respective engaging portions 54a and 60a of the
And the toothless portions 55d, 5 of the second toothless gears 55, 59
Since 9d is in a position facing the drive gear 78, the drive gear 78 and the first and second tooth-chipped gears 55 and 59 do not mesh with each other, so that the drive force of the drive gear 78 is the same as that of the first and second gears. It is not transmitted to the tooth-chipped gears 55, 59 and therefore the drive gear 7
Even if 8 rotates, the paper feed roller 51 shown in FIG. 4 does not rotate and the recording paper 74 is not fed.

On the other hand, as shown in FIG.
Is turned on, and the second hook 62 is connected to the coil spring 65.
When it is rotated counterclockwise around the fulcrum 81 against the urging force of, the engagement between the engagement claw 64 and the engagement portion 60a of the second stopper cam 60 is released.

When the solenoid 63 is turned on and the engagement between the second hook 62 and the engaging portion 60a of the second stopper cam 60 is released, the solenoid 63 is turned off and the solenoid 63 is arranged on the rear surface of the solenoid 63. 65 of the return spring installed
The engaging claw 64 is moved by the urging force of the second stopper cam 60.
Press against the peripheral surface of.

When the engagement between the second hook 62 and the engaging portion 60a of the second stopper cam 60 is released in this way, the pulling force of the coil spring 70 serving as the second biasing means 69 causes the second hook 62 to disengage. Second integrally formed toothless gear 5
9, second stopper cam 60, and disengagement cam 61
Rotates clockwise around the drive shaft 52. The rotation angle is the guide hole 59 formed in each of the second tooth-chipped gear 59, the second stopper cam 60, and the engagement release cam 61.
Needless to say, it is limited by b, 60b, 61b (FIG. 3).

On the other hand, when the second toothless gear 59 rotates clockwise as shown in FIG. 7, the second toothless gear 5 is rotated.
9 and the drive gear 78 mesh with each other, whereby the second toothless gear 59 is further rotated clockwise around the drive shaft 52.

As described above, when the second toothless gear 59 further rotates clockwise around the drive shaft 52, the second stopper cam 60 and the engagement release cam 61 also rotate clockwise, As shown in FIG. 8, the engagement release cam 61
The tongue piece 57 whose top 61a constitutes the hook separating means 71
Of the tongue piece 57 constituting the first hook 56 by pressing the tongue piece 57b against the left front portion 57b and rotating the tongue piece 57 clockwise around the shaft 80 against the biasing force of the coil spring 58. The engagement between the engaging claw 57a and the engaging portion 54a of the first stopper cam 54 is released.

In this way, when the engagement between the first hook 56 and the engaging portion 54a of the first stopper cam 54 is released, the pulling force of the coil spring 68, which is the first urging means 67, is applied. The first tooth-chipped gear 55 rotates clockwise around the drive shaft 52.

Then, as shown in FIG. 9, when the first tooth-chipped gear 55 rotates clockwise, the first tooth-chipped gear 55 and the drive gear 78 mesh with each other, whereby the first tooth-chipped gear 55 is formed. The gear 55 further rotates in the clockwise direction, the biasing force releasing cam 72 via the drive shaft 52, and the sheet feeding roller 51 shown in FIG.
Rotate clockwise.

As shown in FIG. 9, the bias release cam 7
2 rotates together with the paper feed roller 51 (FIG. 3) and the engagement between the urging force releasing cam 72 and the pin 73a is released, the sheet stacking plate 73 is moved upward by the urging force of the urging spring 75. The uppermost surface of the recording paper 74 stacked and accommodated on the paper stacking plate 73 shown in FIG. 4 is brought into pressure contact with the peripheral surface of the paper feed roller 51 to start feeding the recording paper 74.

As described above, the first and second toothless gears 5
As shown in FIG. 10, when the second tooth-chipped gear 59 makes one full rotation as shown in FIG. 10, the engaging claws 64 forming the second hooks 62 engage the second stopper cams 60. The second tooth missing gear 59 is engaged with the portion 60a again.
Since the tooth-chipped portion 59d of the drive gear 78 and the drive gear 78 oppose each other, the transmission of the driving force to the second tooth-chipped gear 59 by the drive gear 78 is stopped, and thus the second tooth-chipped gear 59 formed integrally, Second stopper cam 60 and disengagement cam 6
One rotation will stop at the same time.

On the other hand, in FIG. 10, since the tooth engagement between the drive gear 78 and the first tooth-chipped gear 55 continues, when the first tooth-chipped gear 55 further rotates to one rotation, as shown in FIG. The engaging claw 57a of the first hook 56 and the engaging portion 54a of the first stopper cam 54 are engaged with each other as in the initial position of 1 to restrict the rotation of the first stopper cam 54, and
The tooth-chipped portion 55d of the first tooth-chipped gear 55 and the drive gear 78
Oppose to each other and the transmission of the driving force to the first tooth-chipped gear 55 by the driving gear 78 is also stopped.

When the first tooth-missing gear 55 makes one rotation in this way, the paper feed roll 51 makes one rotation via the drive shaft 52 and one recording paper 74 shown in FIG. 4 is fed from the uppermost surface thereof. .

Needless to say, when the paper is fed again, the above operation may be repeated.

That is, according to the rotation control device 53 of the present invention described above, the upward biasing force of the biasing spring 75 shown in FIG. 4 is transmitted to the drive shaft 52 via the pin 73a and the biasing release cam 72, and By the drive shaft 5
Although the sliding resistance between the bearing 2 and the bearing 76 supporting the same is increased, the urging force of the first urging means 67 for urging the first tooth-chipped gear 55 in one direction against the sliding resistance is increased. Even when increasing and maintaining the smooth rotation of the paper feed roll 51,
It is not necessary to increase the capacity of the solenoid 63.

That is, as shown in FIG. 3, the engagement between the engaging portion 60a of the second stopper cam 60 and the second hook 62 of the solenoid 63 depends on the urging force of the second urging means 69. Further, the second stopper cam 60 is rotatable about the drive shaft 52, and the upward biasing force of the biasing spring 75 shown in FIG. 4 does not affect the rotation of the second stopper cam 60 at all. From the second stopper cam 6
0 engaging portion 60a and second hook 62 of solenoid 63
Engagement with and does not need to be strong, and therefore a tension coil spring having a small biasing force can be used as the second biasing means 69. Therefore, the engaging portion 60a of the second stopper cam 60 and the solenoid 63 can be used. Of the second stopper cam 60 has a small engaging force with the second hook 62, and therefore a small solenoid 63 having a small capacity is used.
The engagement between 0a and the second hook 62 and the release thereof can be achieved.

[0082]

As described above, in the rotation control device for the sheet feeding device of the present invention, the urging force of the first urging means for initial rotation of the sheet feeding roll is increased to stabilize the sheet feeding roll. The rotation and reliable rotation control can be performed, and the capacity of the solenoid for starting the rotation control can be reduced to reduce the size of the solenoid, which leads to downsizing of the entire rotation control device. It is possible to reduce the size of the image forming apparatus by setting the installation space of the rotation control device to be small.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an image forming apparatus to which a rotation control device of the present invention is applied.

FIG. 2 is a partially cutaway enlarged view of the image forming apparatus showing a portion to which the rotation control device of the present invention is applied.

FIG. 3 is an exploded perspective view of a sheet feeding device including a rotation control device according to the present invention.

FIG. 4 is a front view of a sheet feeding device including a rotation control device according to the present invention.

FIG. 5 is a conceptual sectional view of a main part of a rotation control device according to the present invention.

FIG. 6 is an enlarged side view showing the operation of the rotation control device according to the present invention.

FIG. 7 is an enlarged side view showing the operation of the rotation control device according to the present invention.

FIG. 8 is an enlarged side view showing the operation of the rotation control device according to the present invention.

FIG. 9 is an enlarged side view showing the operation of the rotation control device according to the present invention.

FIG. 10 is an enlarged side view showing the operation of the rotation control device according to the present invention.

FIG. 11 is a front view showing a conventional rotation control device.

FIG. 12 is a left side view of FIG. 11.

[Explanation of symbols]

50 ... Paper feeding device 51 ... Paper feeding roll 52 ... Feed roll drive shaft 53 ... Rotation control device 54 ... First stopper cam 55 ... 1st toothless gear 56 ... first hook 59 ... second toothless gear 60 ... Second stopper cam 61 ... Engagement release cam 62 ... second hook 67 ... First biasing means 69 ... Second biasing means 71 ... Hook separating means 78 ... Drive gear

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 3/06 350 G03G 15/00 514

Claims (5)

(57) [Claims] 1. A rotation control device for a sheet feeding device that feeds sheet-shaped recording sheets one by one by rotating the sheet feeding roll once, and independently supports a sheet feeding roll at one end and non-rotatably at the other end. The first non-toothed gear is independently and non-rotatably supported, and the first non-rotatably supported first stopper cam is independently supported between the first non-toothed gear and the paper feed roll. A paper roll drive shaft, a first hook that engages with an engaging portion of the first stopper cam, and a rotatably supported by the paper feed roll drive shaft adjacent to the first toothless gear. A second toothless gear and a second stopper adjacent to the second toothless gear, rotatably supported by the paper feed roll drive shaft, and rotating integrally with the second toothless gear. A cam and a rotation on the paper feed roll drive shaft adjacent to the second stopper cam An engagement disengagement cam that is supported in place and that rotates together with the second stopper cam; a second hook that engages with an engagement portion of the second stopper cam; and the first toothless gear. First biasing means for biasing in the rotation direction, second biasing means for biasing the second toothless gear in the rotation direction, and rotation of the disengagement cam cause the first hook to move. A hook separating means for separating from the engaging portion of the first stopper cam meshes with the first toothless gear and the second toothless gear, and the first toothless gear and the second toothless gear. A rotation control device for a sheet feeding device, comprising: 2. A first hook that engages with an engaging portion of the first stopper cam is formed at the tip of a rotatable tongue piece that is constantly biased toward the cam face side of the first stopper cam. The rotation control device for a sheet feeding device according to claim 1, wherein the rotation control device is an engaged claw. 3. The second hook engaging with the engaging portion of the second stopper cam is an engaging claw that can be engaged and released by a solenoid. A rotation control device for the sheet feeding device described. 4. A torsion spring, a compression coil spring, or a tension coil spring is used as the second urging means for urging the second toothless gear in the rotating direction, and one end of the spring is It engages with either the second toothless gear, the second stopper cam, or the disengagement cam, and the other end has the first stopper cam, the first toothless gear, the feed roll drive shaft, Claim 1 characterized in that it engages with any one of the paper feed rolls.
A rotation control device for the sheet feeding device described. 5. A hook separating means for separating the first hook from the engaging portion of the first stopper cam by the rotation of the engagement releasing cam is a plate-like member formed integrally with the first hook. The rotation control device for a paper feeding device according to claim 1, wherein the rotation control device is a tongue piece.