JPH11246067A - Torque limiter, sheet feeding device, and image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily change transmission torque according to a sheet type or sheet thickness by providing a torque limiter with a plurality of coil springs and selectively adding fastening force by each coil spring. SOLUTION: A torque limiter 37 is constituted with coaxially rotatable inner and outer ring members 40, 41, coil springs 42a, 42b, 42c, engaging members 43a, 43b, 43c attachable/detachable to the outer ring member 41. The outer ring member 41 is composed of transparent synthetic resin so that positions of each of ends 42a1, 42b1, 42c1 of the coil springs, and engaging holes 44a, 44b, 44c are provided on a sliding surface of the coil springs 42a, 42b, 42c. The engaging members 43a, 43b, 43c are respectively adhered to the engaging holes 44a, 44b, 44c of the outer ring member 41, and can be engaged with the ends 42a1, 42b1, 42c1 of the coil springs. By inserting and fixing an A part with long inserting part of the engaging members into the engaging holes when they are engaged with the coil springs, and B part with short inserting part of the engaging members into the engaging holes when they are not engaged with the coil springs, a slip torque is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter for transmitting a predetermined range of torque, a sheet feeding device using the same, and an image processing device.

[0002]

2. Description of the Related Art Torque limiters are used in sheet feeding devices such as copying machines, printers, and facsimile machines.

FIGS. 7 and 8 show examples of a sheet feeding apparatus. In the figure, a retard roller 100 is pressed against a feed roller 101 at a predetermined pressure, and a sheet bundle sent by a pickup roller (not shown) is sandwiched in a nip portion. The retard roller 100 has
A constant torque T is always applied in the direction of returning the seat 103 via the torque limiter 102. Here, as shown in FIG. 7, when two or more sheets are sandwiched between the feed roller 101 and the retard roller 100, the second and subsequent sheets are separated from the first sheet, and Is returned in the opposite direction.

However, when the feed roller 101 and the retard roller 100 are in direct contact with each other or when only one sheet is sandwiched between the feed roller 101 and the retard roller 100 as shown in FIG. Follow the direction of sending. Therefore, in order to reliably feed the sheets 103 one by one, the sheet conveying force generated by the reverse rotation torque T applied to the retard roller 100 by the torque limiter 102 is larger than the frictional force between the sheets, but the feed roller 101 Must be smaller than the sheet conveyance force. And the torque limiter
Torque T applied to retard roller 100 by 102
And the pressing force for pressing the retard roller 100 against the feed roller 101 depends on the type of sheet to be fed, environmental conditions,
Alternatively, the appropriate value slightly varies depending on the material of the rollers 100 and 101.

As the torque limiter 102, there is a torque limiter utilizing a tightening force of a coil spring. For example, a torque limiter as shown in FIG. 9 is used. The torque limiter 102 shown in FIG. 9 includes an inner ring member 104, an outer ring member 105, a coil spring 106 interposed therebetween, and a lid 107 fitted to the inner diameter surface of the outer ring member 105. Grease is filled in the gap with 105. The coil spring 106 is fitted to the inner ring member 104 with a fixed tightening force, and serves as a torque generating unit. Also, the end 106a of the coil spring 106
Is engaged with the lid 107.

The torque limiter 102 transmits the torque applied to the inner ring member 104 to the outer ring member 105 via the coil spring 106 when the magnitude of the torque is smaller than the force with which the coil spring 106 tightens the inner ring member 104. . However, when the magnitude of the torque exceeds the above-described tightening force, the transmission of the torque is interrupted, so that the function as a torque limiter is exhibited.

[0007]

However, the above-described conventional torque limiter is normally used by setting a predetermined slip torque value in a manufacturing stage. Therefore, when used in a sheet feeding device such as a copying machine, the slip torque value differs for each sheet feeding device to be used, so that it is necessary to prepare a torque limiter for each feeding device to be used.

Further, in recent years, various sheets have been used, and it has become necessary to change the slip torque value according to the sheet type, sheet thickness and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a torque limiter capable of easily changing a transmission torque value according to a sheet type, a sheet thickness, and the like. And a sheet feeding apparatus and an image forming apparatus using the same.

[0010]

A typical configuration according to the present invention for achieving the above object is to transmit a predetermined range of torque through a tightening force of a coil spring interposed between an inner ring member and an outer ring member. In the torque limiter, a plurality of the coil springs are provided, and the tightening force of each coil spring can be selectively applied.

The inner ring member and the outer ring member are rotatable about the same central axis, and a plurality of coil springs are fitted on the outer peripheral surface of the inner ring member, and one end of the coil spring is connected to the inner ring member. The outer ring member is provided with an engagement hole at a position corresponding to the other end of the coil spring, and an engagement member engageable with the other end of the coil spring corresponding to the engagement hole is selectively mounted. In the above configuration characterized in that the transmission torque can be changed, the transmission torque can be changed by selectively using the coil spring.

Therefore, by using the torque limiter having the above structure in the sheet feeding device, it becomes possible to separate the sheets by transmitting appropriate torque to various sheets, and to feed the sheets without double feeding. Image processing can be performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a torque limiter, a sheet feeding device, and an image processing device to which the present invention is applied will now be described with reference to the drawings.

[First Embodiment] A torque limiter and the like according to a first embodiment will be specifically described with reference to FIGS. 1 is an explanatory cross-sectional view of a configuration of a torque limiter, FIG. 2 is an overall schematic explanatory view of a copying machine as an example of an image processing apparatus, FIG. 3 is an overall schematic explanatory view of a sheet feeding apparatus, and FIG. FIG. 4 is an explanatory diagram of a drive transmission configuration to a sheet feeding unit.

Here, as a sequence of the description, first, the overall configuration of the copying machine as the image processing apparatus will be described, and then the sheet feeding apparatus and the torque limiter will be described.

{Overall Configuration of Image Processing Apparatus} As shown in FIG. 2, the image processing apparatus according to the present embodiment has a feeding deck 2 in which a large number of sheets S are stacked and stored on one side of an image processing apparatus main body 1. And a plurality of feed cassettes 3 in which a predetermined amount of sheets S are stacked and stored in the lower portion of the image processing apparatus main body 1.
4 is provided.

The feed deck 2 serving as a feed unit for feeding the sheets S, and the sheet feeding devices 5, 6, 7 of the retard separation type are provided at the installation sites of the respective feed cassettes 3, 4. Is provided. The feeding device will be described later in detail.

When the sheets S in the feeding deck 2 and the feeding cassettes 3 and 4 are fed by the respective sheet feeding devices 5, 6 and 7, first, the sheets S are fed to the registration roller pair 8 which has stopped rotating. Then, the skew state is corrected here.

Next, based on the information optically read by the reading means 21, a registration roller pair which rotates at a timing with a latent image formed on the photosensitive drum 9 constituting an image forming portion as a processing means. 8, the photosensitive drum 9
, And the toner image on the photosensitive drum 9 is transferred here.

Thereafter, the sheet S is sent to the fixing device 12 by the transport belt 11, and a fixing process for fixing the transferred toner image on the sheet surface is performed.

The image processing apparatus is provided with a duplex copying mode for performing duplex copying on the sheet S and a multiplex copying mode for performing multiple copying. In the normal copying mode (single-sided copying mode), the sheet S after the fixing process is performed. Is discharged onto a discharge tray 15 outside the apparatus by an inner discharge roller pair 13 and an outer discharge roller 14.

In the case of the double-sided copy mode and the multiple copy mode, the pair of inner discharge rollers 13 or the pair of switchback rollers 16 temporarily place the sheet on the intermediate tray 19 via the re-feeding path 17 and the double-sided conveying path 18. It is loaded and stored.

Then, the sheet S stored on the intermediate tray 19 is again conveyed to the registration roller pair 8 for image formation by the re-feeding device 20, and thereafter discharged out of the apparatus through the same process as for one-sided copying. You.

{Sheet Feeding Apparatus} Next, the sheet feeding apparatuses 5, 6, and 7 will be described. Here, the configuration of the feeding device 5 will be described as an example, but it goes without saying that the other feeding devices 6 and 7 may have the same configuration as needed.

The sheet feeding device 5 sequentially separates and feeds the sheets one by one toward the above-described image forming section. As shown in FIG. 3, a plurality of sheets S are stacked and stored. Roller 22 that feeds the uppermost sheet S one by one from the feeding deck 2, and a separation roller that conveys the sheet S fed from the feeding deck 2 by the pickup roller 22 into the image processing apparatus main body. Vs. 23,
A registration roller pair 8 for transporting the separated sheet S to the downstream side is provided.

The separation roller pair 23 is a feed roller 24, which is a rotating body that rotates in the direction in which the sheet is conveyed, and a rotating body that rotates in a direction in which the feed roller 24 comes into contact with the feed roller 24 at a predetermined pressure and returns the sheet. It comprises a retard roller 25.
The pickup roller 22, the feed roller 24 and the retard roller 25 of the separation roller pair 23 are connected to a drive source (
(Not shown). That is, the rotational power of the drive source is transmitted to the roller shaft 28 of the feed roller 24 via the drive belt 26 and the electromagnetic clutch 27.

The rotational power transmitted to the roller shaft 28 of the feed roller 24 is transmitted 1: 1 to the pickup roller shaft 32 of the pickup roller 22 via the pulley 29, the timing belt 30, and the pulley 31. Further, the rotational power from the roller shaft 28 is supplied to the pulley 33, the timing belt 34, and the pulley 35.
And transmitted to a relay shaft 36 of the retard roller 25 via a torque limiter 37 and a coupling 38 described later.

When a voltage is applied to the electromagnetic clutch 27, the rotational power of the drive source is transmitted to the roller shaft 28,
Reference numeral 24 rotates in the direction in which the sheet is conveyed (the direction of arrow A).
Further, the pickup roller 22 also rotates via the timing belt 30 in the direction for transporting the sheet (the direction of arrow C). The rotation of the roller shaft 28 is transmitted to the relay shaft 36 via the timing belt 34. Accordingly, the retard roller 25 rotates in a direction (arrow B direction) to return the sheet S in synchronization with the rotation of the feed roller 24. But retard roller 25
When the torque greater than the set value is applied because the rotational power is transmitted through the torque limiter 37, the retard roller 25
Is idle, and is driven to rotate by the feed roller 24.

The sheet fed by the pickup roller 22 to the nip portion of the separation roller pair 23 as described above
When there is only one sheet, the retard roller 25 becomes idle,
The sheet is conveyed downstream by rotating following the feed roller 24. When a plurality of sheets fed by the pickup roller 22 enter, the retard roller 25 rotates in the direction of arrow B, so that the sheets other than the uppermost layer are returned to the retard roller 25 and Only the upper layer is separated and transported downstream.

{Torque Limiter} Next, the structure of the torque limiter 37 will be described with reference to FIG. As shown in the figure, the torque limiter 37 comprises an inner ring member 40 and an outer ring member 41 rotatable about the same central axis, three coil springs 42a, 42b, 42c interposed between the two members, and Three engaging members detachably provided to the member 41
43a, 43b and 43c. The gap between the inner ring member 40 and the outer ring member 41 is filled with grease. The inner ring member 40 is connected to the relay shaft 36 to transmit the rotational force, and the outer ring member 41 is connected to the retard roller 25 via the coupling 38.

The coil springs 42a, 42b and 42c are fitted on the outer peripheral surface of the inner ring member 40 with a predetermined tightening force.
The outer ring member 41 is made of a transparent synthetic resin so that the positions of the respective ends 42a1, 42b1, 42c1 of the coil springs 42a, 42b, 42c can be recognized, and the coil springs 42a, 42b, 42c.
Engaging holes 44a, 44b, 44c are provided on the sliding surface of c. The engaging members 43a, 43b, 43c are respectively mounted in the engaging holes 44a, 44b, 44c of the outer ring member 41, and the respective ends 42a1, 42b1, 42c1 of the coil springs 42a, 42b, 42c.
And can be engaged.

The engaging members 43a, 43b, 43c are
When engaging with the coil springs 42a, 42b, 42c, the insertion portion A having a long insertion portion is inserted and fixed in the engagement holes 44a, 44b, 44c, and when not engaging with the coil springs 42a, 42b, 42c, the insertion portion is short B portion Is inserted and fixed in the engagement hole so that the engagement hole 44 is
a, 44b, and 44c function as lids for closing.

When it is desired to reduce the slip torque value of the torque limiter, as shown in FIG. 1 (b), the engaging member 43a is mounted on the engaging hole 44a of the outer race member 41.
Engage with the end 42a1 of the coil spring 42a. Thus, when the inner ring member 40 rotates, only the coil spring 42a becomes a portion that generates slip torque, and the other coil springs 42b and 42c rotate integrally with the inner ring member 40 and do not generate slip torque. Accordingly, since the width of tightening the outer peripheral portion of the inner ring member 40 is small, the slip torque value is small.

Next, when it is desired to increase the slip torque value of the torque limiter 37, as shown in FIG. 1 (c), all three engagement members 43a, 43b, 43c are engaged with the outer ring member 41. Attached to the holes 44a, 44b, 44c, the coil spring 42
a, 42b, 42c are engaged with the ends 42a1, 42b1, 42c1. As a result, when the inner ring member 40 rotates, the three coil springs 42a, 42b, and 42c become portions where slip torque is generated, and the width of tightening the outer peripheral portion of the inner ring member 40 is large, so that the slip torque value increases.

The torque limiter 37 of this embodiment can set three levels of slip torque by providing three engaging members 43a, 43b and 43c. Therefore, three stages of torque adjustment are possible.

By selecting the number of the engagement members 43a, 43b, 43c to be attached as described above, the magnitude of the slip torque by the coil spring can be changed, and the retard roller 25 can be changed according to the type and thickness of the sheet. It is possible to easily change the torque transmission value to the motor.

[Second Embodiment] Next, a second embodiment of the torque limiter will be described with reference to FIG. FIG. 5 is an explanatory diagram of a cross-sectional configuration of a torque limiter according to the second embodiment.

As shown in FIG. 5, the torque limiter of this embodiment is provided with three coil springs 45a, 45b and 45c having different fastening forces, instead of the coil springs 42a, 42b and 42c of the first embodiment. Things.
Since the coil springs 45a, 45b, and 45c have different tightening forces in stages, respectively, the coil springs 45a, 45b,
45c have different frictional forces with the outer peripheral portion of the inner ring member 40.

Accordingly, any one of the engagement holes 44a, 44b, 44c of the outer race member 41 is engaged so that the engagement members 43a, 43b, 43c are engaged with any one of the coil springs 45a, 45b, 45c.
By mounting the two, the slip torque value can be set in three stages, and the torque can be adjusted in three stages.

[Third Embodiment] Next, a third embodiment of the torque limiter will be described with reference to FIG. FIG. 6 is a sectional configuration explanatory view of a torque limiter according to the third embodiment.

The torque limiter of this embodiment of the present embodiment is different from the torque limiter of the first embodiment in that
A step is formed on the outer peripheral surface as shown in FIG.
The tightening forces b and 42c are set in three stages.
The coil springs 42a, 42b, and 42c have different tightening forces because the outer diameters of the inner ring members 40 to be fitted are different from each other. The power will be different.

Accordingly, any one of the engagement holes 44a, 44b, 44c of the outer race member 41 is engaged so that the engagement members 43a, 43b, 43c are engaged with any one of the coil springs 42a, 42b, 42c.
By mounting the two, the slip torque value can be set in three stages, and the torque can be adjusted in three stages.

[Other Embodiments] In the above embodiment,
Although an example in which three coil springs are fitted to the inner ring member 40 is shown, the number of fitted springs does not need to be limited to three.
If the number is two or more, the slip torque value can be changed, and if the number of springs is large, the torque value can be changed more finely.

In the above-described embodiment, the example in which the torque limiter is used in the sheet feeding device has been described. However, the torque limiter is also suitably used in a device other than the sheet feeding device for changing and transmitting the rotational torque. be able to.

In the above-described embodiment, the case where the sheet feeding apparatus feeds the recording sheet of the copying machine has been described.
This sheet feeding apparatus can also be suitably used for an image reading apparatus or the like that separates and feeds a plurality of set originals one by one and reads the written information of the originals. Therefore, the image processing apparatus may be not only an image forming apparatus such as a copying machine or a printer but also an image reading apparatus such as a scanner.

[0046]

The present invention is constructed as described above.
By changing the tightening force of the coil spring, the transmission torque can be changed.

Therefore, by using the torque limiter having the above-described structure in the sheet feeding device, it becomes possible to separate the sheets by transmitting appropriate torque to various sheets, and to feed the sheets without double feeding. Image processing can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a configuration of a torque limiter.

FIG. 2 is an overall schematic diagram illustrating a copying machine as an example of an image processing apparatus.

FIG. 3 is an overall schematic explanatory view of a sheet feeding device.

FIG. 4 is an explanatory diagram of a drive transmission configuration to a sheet feeding unit.

FIG. 5 is a sectional configuration explanatory view of a torque limiter according to a second embodiment.

FIG. 6 is a sectional configuration explanatory view of a torque limiter according to a third embodiment.

FIG. 7 is a diagram illustrating a state in which a plurality of sheets are separated and fed by a feed roller and a retard roller.

FIG. 8 is an explanatory diagram illustrating a state in which one sheet is fed by a feed roller and a retard roller.

FIG. 9 is an explanatory cross-sectional view of a configuration of a torque limiter according to a conventional technique.

[Explanation of symbols]

 S: Sheet 1: Image processing apparatus main body 2: Feeding deck 3, 4, Feeding cassette 5, 6, 7 ... Sheet feeding device 8: Registration roller pair 9: Photoconductor drum 10: Transfer charger 11: Conveying belt 12 ... fixing device 13 ... inner discharge roller pair 14 ... outer discharge roller 15 ... discharge tray 16 ... switchback roller pair 17 ... re-feed path 18 ... double-sided conveyance path 19 ... intermediate tray 20 ... re-feed device 21 ... reading means 22 ... pickup roller 23 ... separation roller pair 24 ... feed roller 25 ... retard roller 26 ... drive belt 27 ... electromagnetic clutch 28 ... roller shaft 29 ... pulley 30 ... timing belt 31 ... pulley 32 ... pickup roller shaft 33 ... pulley 34 ... timing Belt 35 pulley 36 relay shaft 37 torque limiter 38 coupling 39 roller shaft 40 inner ring member 41 outer ring members 42a, 42b, 42c coil spring 42 1, 42b1, 42c1 ... end 43a, 43b, 43c ... engaging members 44a, 44b, 44c ... engaging holes 45a, 45b, 45c ... coil spring

Claims (6)

[Claims] 1. A torque limiter for transmitting a predetermined range of torque through a tightening force of a coil spring interposed between an inner ring member and an outer ring member, wherein a plurality of the coil springs are provided, and the tightening force of each coil spring is selectively applied. A torque limiter characterized by being made possible. 2. A torque limiter for transmitting a predetermined range of torque through a tightening force of a coil spring interposed between an inner ring member and an outer ring member, wherein the inner ring member and the outer ring member are turned around the same central axis. Movably configured, a plurality of coil springs are fitted on the outer peripheral surface of the inner ring member, one end of the coil spring is engaged with the inner ring member, and the outer ring member is engaged with a position corresponding to the other end of the coil spring. A torque limiter comprising a hole, and an engagement member engageable with the other end of the coil spring corresponding to the engagement hole is provided so as to be selectively mounted. 3. The torque limiter according to claim 2, wherein the plurality of coil springs have different tightening forces for tightening the inner race member. 4. The torque limiter according to claim 2, wherein the outer diameter of the inner race member to which the plurality of coil springs are fitted is different. 5. A sheet feeding apparatus for separating and feeding sheets one by one, comprising: a feeding rotator that rotates in a sheet feeding direction; and a direction in which the sheet is pressed against the feeding rotator and the sheet is returned. And a retard rotating body that rotates to transmit the rotational force to the retard rotating body via the torque limiter according to any one of claims 1 to 4. apparatus. 6. An image processing apparatus for performing image processing by feeding a sheet, wherein the image processing unit performs image processing on the sheet fed by the sheet feeding apparatus. An image processing apparatus, comprising: