JPH0246495B2 - SHOKYUSOSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The disclosed technology belongs to the technical field of mechanisms for feeding paper sheets having information-recorded sides, such as facsimiles and electronic copiers.

Therefore, the present invention is provided in a paper feeding section of a paper sheet information processing apparatus such as a facsimile machine or an electronic copying machine, and is provided in front of the paper sheet stack tray and is connected to a drive device such as a motor. It consists of a feed roller and a conveyance roller placed in front of it, which consists of connected rubber friction rollers, etc. A separation roller is placed above and in contact with the feed roller, and a pressure contact is made with the conveyance roller. This invention relates to a paper feeding device in which a roller is placed in pressure contact with the upper roller to pull in and feed paper sheets, and in particular, the pressure roller makes contact and pressure contact with the separation roller and the pressure roller with different circumferential surfaces. This invention relates to a paper feeding device which is formed so that the rotating pressure contact peripheral surface of the conveying roller via the pressure contact roller and the contact peripheral surface of the separation roller do not overlap with each other.

[Background of the invention]

As is well known, in recent years, rapid mass processing of information has been carried out in various fields, and facsimiles, electronic copiers, printers, automatic form processing devices, etc. are used for this purpose. In most cases, a large amount of primary input paper sheets with graphical information such as numbers written on them are supplied.

For high-speed, large-volume processing, these primary input sheets are usually stacked in a stacked manner on a sheet stacking tray provided on the supply side, and are fed forward one sheet at a time from the bottom or top. ing.

As a means for forward paper feeding, a method using the friction width of a rubber roller is generally adopted, and when this is established as shown in FIG. 2 is upwardly biased by a pressing spring 4 provided on a frame 3 to press a group of 5 sheets stacked on the stacking tray 2 against a separation roller 6, and as the separation roller 6 rotates, the uppermost sheet is separated. 5 is forward-fed and fed to a pressing member 8 which is biased via a pressing spring 7 provided on the frame 3 and a feeding roller 9 which rotates in contact with the pressing member 8, and the rotation of the feeding roller 9 and the feeding roller 9 rotate. Pressing material 8
The paper sheet 5 is fed in the direction of the front guide rollers 10 through the pinching action of the rollers.

Therefore, since the pressing member 8 performs stationary pressing and the feeding roller 9 performs rotational pressing, even if two or more sheets are forwarded from the stacking tray 2 by the separating roller 6, only the topmost sheet is reliably delivered. It is set to be forwarded.

By the way, most of the input paper sheets have input image information written on them as mentioned above, and the writing methods include pen writing, of course, but also pencil writing, paper powder toner, carbon, carbon ink, correction fluid, eraser adhesion etc. Therefore, if this type of image information is written or the transfer sheet is fed from the input side, not only the separation roller 6 but also the feed roller 5 and the pressing material 8 may be damaged due to frequent and repeated use. These carbons and the like adhere.

This repeated phenomenon over time is particularly noticeable when image information is written on the upper surface of the original sheet, and the carbon adhering to the feed roller 9 is transferred to the pressing material 8, which has an initial designed friction coefficient. (resistance) becomes impossible to maintain, and the stationary pinching function of the pressing member 8, that is, the reliable single sheet feeding function is impaired,
There was a drawback that multiple sheets of original paper were sent.

In particular, there was a problem that had a large effect on thin paper sheets, the need for which has increased significantly in recent years.

In addition, in this case, changes in frictional resistance due to dirt such as carbon on the separating roller 6 and the feeding roller 9 impair the designed feeding and passing function, and the sheet may buckle or fold as shown by the dotted line. bend or
In some cases, it may tear and cause so-called jams, resulting in maintenance, inspection, etc.
It also had the disadvantage of high maintenance costs.

[Purpose of the invention]

The purpose of the present invention is to solve the problem of the deterioration of the feeding function due to dirt such as carbon on the feeding roller for a large number of sheets with image information such as facsimile, which is based on the above-mentioned prior art, and to design the roller. By making it simple and rational, it prevents and reduces the adhesion of carbon, etc., prevents jamming, etc., and maintains a reliable paper feeding function for paper sheets, and is useful in the field of paper sheet information input use in the information industry. The purpose of this invention is to provide an excellent paper sheet feeding device that will benefit the user.

[Summary of the invention]

In order to solve the above-mentioned problems, the structure of the present invention, which is based on the above-mentioned claims in accordance with the above-mentioned object, is to solve the above-mentioned problems. The part is forward-energized,
A feed roller with friction provided at the front, followed by a conveyance roller installed in front, apply a feeding force, and a pressure roller attached to the conveyance roller is fed forward to the conveyance roller in a pinched state. The rotational torque applied by the pressure roller of the pressure roller that is pressed between the conveyance roller and the separation roller that presses the above-mentioned feed roller is more than two sheets of the feed roller. The feed torque is set to be greater than the feed torque of one sheet of the feed roller, and return spin is applied to two or more sheets of paper to check the forward feed, and the feed torque of one sheet of the feed roller is set to be equal to or smaller than the feed torque of one sheet of the feed roller. This ensures that only one sheet of paper is forwarded by causing slippage, and furthermore, the contacting peripheral surface of the pressure roller against the conveying roller and the contacting peripheral surface against the separation roller are axially misaligned and the conveying roller The dirt on the paper sheet that has been transferred to the feed roller is not transferred to the pressure roller, but rather is peeled off by the pressure roller, and the conveyance friction function of the conveyance roller is maintained.On the other hand, the stain that has been transferred to the feed roller is transferred to the separation roller. The sheet is peeled off by the pressure roller that comes into contact with the separation roller, and as a result, the function of the feed friction surface of the feed roller is maintained, and technical measures have been taken to ensure that each sheet is fed reliably. .

[Embodiments of the invention]

Next, an embodiment of the present invention will be described below based on the drawings from FIG. 2 onwards. Note that the same reference numerals are given to the same parts as those shown in FIG. 1 for explanation.

2 to 8, reference numeral 11 denotes a paper sheet feeding device which constitutes the gist of the present invention, and in this embodiment, it is provided in a paper feeding section of a facsimile machine (not shown), and is similar to a conventional general paper sheet feeding device. They are compatible.

The sheet tray 2' provided on the frame of the facsimile has a predetermined inclination angle in the forward direction, and is connected to the front guide panel 12.

As shown in FIG. 4, a drive motor 13 is provided with belts 14, 15 and a pulley 16 at the transfer section between the sheet tray 2' and the guide panel 12.
Rotating shafts 18 and 19 are provided via the rotating shaft 17, and a pair of rubber conveyance rollers 20 and 20 for feeding paper sheets are provided on the left and right sides of the rotating shaft 18. A pair of feed rollers 9', 9' are also shaft-mounted via a one-way clutch 21.

The rotating shafts 18 of each of the conveying rollers 20 are supported by bearings 24 slidably provided in notches 23 of the brackets 22 provided on both sides of the guide panel 12, as shown in FIG. A resilient spring 25 is interposed between the bearing 24 and the bracket 22.

On the other hand, a bearing 24', which is slidably disposed opposite to a bearing 24 in a notch 23 of the bracket 22, has an elastic spring 2 between it and the bracket 22.
A rotating shaft 26 is mounted on the bearing 24', and a pair of rubber pressure rollers 28, 28 are loosely inserted into the rotating shaft 26 via a bearing 27. has been done.

Each pressure roller 28 has a circumferential surface 29 of a large diameter portion and a circumferential surface 30 of a small diameter portion of a predetermined size, and each has a U-shaped groove 31 in cross section of a predetermined size in the axial direction. The large-diameter circumferential surface 29 is engraved to ensure cleaning of carbon, etc., which will be described later, and pressure-contact driving, and the circumferential surface 29 of the large-diameter portion is biased against each corresponding conveyance roller 20 via the elastic springs 25 and 25'. ing.

Further, reference numerals 6' and 6' designate rubber separation rollers, which are loosely supported by a support shaft 32 which is floatingly supported in an approximately vertical direction on a guide bracket (not shown) provided on the guide panel, and due to their own weight. It lightly contacts the feed roller 9' and also lightly contacts the circumferential surface 30 of the small diameter portion of the pressure roller 28.

Therefore, as can be seen from the illustrated state, the feed roller 9' and the conveyance roller 20 are forcedly driven, and the pressure roller 28, which comes into pressure contact with the conveyance roller 20, is a semi-forced driven roller. Therefore, as shown in FIG. 3, the direction of rotation is kept constant.

On the other hand, the separation roller 6' is connected to the pressure roller 28.
and the feed roller 9' is in contact with its own weight, and furthermore,
Since the pressure roller 28 and the feed roller 9' rotate in opposite directions, the pressure roller 28 and the feed roller 9'
It can rotate in both forward and reverse directions due to the difference in frictional torque caused by it, and it can also come to a slip stop.

That is, if the torque of the feed roller 9' is large, the contact with the pressure roller 28 becomes a slip contact, and the feed roller 9' rotates normally in the direction A in FIG. Reverse direction B.

Therefore, in this invention, when the sheet 5 is not fed as shown in FIG.
The friction torque from the pressure contact roller 28 against T _M ,
That from the feed roller 9' is T _F , and as mentioned above, the separation roller 6' is rotated in the normal direction to ensure that the lowest sheet 5 is fed out from the stacking tray 2 _' . T _M ...(1), so that the abutting circumferential surface 30 of the small diameter portion of the pressure roller 28 and the separation roller 6' slip in reverse, thereby causing the abutting circumferential surface of the small diameter portion 30 grooves 31 clean the circumferential surface of the separation roller 6' to remove dirt such as carbon transferred from the upper surface of the paper sheet 5 or the lower surface of the paper sheet 5 to the feed roller 9' and then to the separation roller 6'. It is exfoliated and removed and is made to be difficult to get dirty.

Next, if the feed roller 9' unexpectedly feeds out two or more lowest paper sheets 5 as shown in FIG. 6, the thickness of the two or more paper sheets 5 is increased. Fluctuations in friction torque due to the diameter will occur on the feed roller 6', and if this is T _PP , then T _M > T _PP ...(2) In other words, the separation roller 6' will move in the B direction as shown in Figure 6. If it rotates in the opposite direction, the lowest sheet 5 will be transferred to the feed roller 9'.
The topmost sheet is fed backwards and returned in the R direction, and then the same as the one below it, so that only the bottommost sheet is fed forward. Designed.

Next, as shown in FIG. 7, when the feed roller 9' feeds out only the lowest sheet 5 from the stacking tray 2', which is the designed mode, the separation roller 6' Regarding the friction torque T _P from the feed roller 9' that is received by the separation roller 6', feeding is impossible unless T _P > T _M (3), and the separation roller 6' slips and becomes stationary.

Therefore, from equations (1), (2), and (3) above, the design is such that the following equations are satisfied: T _F > T _P > T _M > T _PP (4).

Of course, in any case, the pressure roller 28
The cleaning effect on the contact peripheral surface 30 of the small diameter part is the same, and the cleaning effect of the contact peripheral surface 29 of the large diameter part of the conveying roller 2 is the same.
It also has a cleaning effect on 0.

In the above configuration, when the facsimile machine is operated, in the starting state, a predetermined number of sheets 5 are stacked on the stacking tray 2' with the image information writing side facing down, as shown in FIGS. 3 and 5.

Therefore, the feed roller 9' and the separation roller 6' are in the feeding rotation position.

Therefore, normally, as shown in FIG. 7, only the lowest paper sheet 5 is fed out, and from the relationship of equation (4), only the feed roller 9' rotates, and the separation roller 6' remains essentially stationary.
The sheet of paper 5 is fed forward, and when its leading edge reaches the large diameter portion of the conveying roller 20 and the pressure roller 28, it is nipped and fed to the facsimile main body.

Therefore, as shown in Figure 6, we unexpectedly decided to
When the sheets (or more) of sheets 5, 5 are fed out, the separation roller 6' rotates in the opposite direction in the B direction due to the above-mentioned function, and immediately returns the second (or more) sheets, resulting in the seventh
As shown in the figure, only the lowest one sheet is forwarded.

Then, at the feeding gap timing of each sheet 5, the separation roller 6' rotates forward in the direction A as shown in FIG.

During this time, in the sheet feeding process shown in FIGS. 6 and 7, the back side of the sheet 5 is
That is, the carbon etc. of the image information structure on the lower surface are transferred and a dirt film is formed once, but the dirt on the conveying roller 20 is caused by the large diameter of the pressure roller 28, as shown in FIGS. 10 to 13 described later. The grooves 31, 31', 31'', 31 as uneven parts formed on the conveying roller contact peripheral surface 29, which is the part, are cleaned,
Remove and peel off carbon etc.

Therefore, in order for this function to be fulfilled more reliably, the axial length of the conveyance roller 20 shown in FIGS. 4 and 8 and the axial width of the abutting circumferential surface 29 of the large diameter portion of the pressure roller 28 must substantially match. It is desirable that the design be designed to do so.

On the other hand, the dirt transferred to the feed roller 9' is secondarily transferred to the separation roller 6' at the timing shown in FIG. Figure 10~
As shown in FIG. 13, it is cleaned and peeled off by grooves 31, 31', 31'', and 31 as uneven parts formed on the separation roller abutting peripheral surface 30, which is the small diameter part of the pressure roller 28. .

The powder, such as carbon, peeled off by the pressure roller 28 is scattered by the whirlwind generated by the rotation of the pressure roller 28, but a suction nozzle may be provided around the powder and forcedly sucked.

In this way, the friction surfaces of the transport roller 20, the feed roller 9', and the separation roller 6' are kept clean at all times, so that the friction coefficient remains unchanged and the forward feeding function of each sheet 5 is maintained. It is maintained reliably and each sheet is fed without wrinkles, curls or jams.

Of course, substantially the same effect is performed on a document in which image information is written on the upper side of the sheet 5.

In the embodiment shown in FIG. 9, the pressure roller 28' is formed such that the diameter of the circumferential surface 30' that contacts the separation roller 6' is the same as the diameter of the circumferential surface 29' that abuts the conveyance roller 20. Conveying roller 2 at different parts
0 and the separation roller 6', but there is no substantial difference from the embodiment described above.

Therefore, in each of the above embodiments, the pressure roller 2
A large number of axial grooves 31 are formed as uneven portions on the conveying roller abutment peripheral surfaces 29, 29' and the separation roller abutment peripheral surfaces 30, 30' of No. 8 to improve the cleaning effect and the effect of improving the pressing friction effect. Although it has been done,
This aspect is shown in FIG. 10, and the cross-sectional shapes of the grooves 31 include trapezoidal, square, triangular, sawtooth shapes, etc., and the arrangement shape with respect to the circumferential surface is shown in FIG. 11. axially inclined groove 3
1', or a knurled groove 31'' as shown in FIG.

Furthermore, as shown in FIG. 13, there are scattered protrusions 31.
, or may be a hole or the like.

Next, regarding the material of each roller 6', 9', 20, 28, based on theory and experiment, for example, the feed roller 9' is made of rubber with a high friction coefficient such as Croixprene or butadiene, and the separation roller For 6', urethane-based rubber, especially foamed urethane rubber, is used.
As mentioned earlier, the separation roller 6' rotates in the forward and reverse directions relative to the feed roller 9', so if the friction coefficients of the two are close, slippage is more likely to occur and fouling may be promoted, so in order to avoid this, It is necessary to choose one with a different friction number.

In addition, by using foamed proloprene rubber or the like in addition to the above-mentioned foamed urethane rubber for the separation roller 6', the surface of the separation roller 6' has fine air bubbles or voids, which is effective in trapping dirt and improving the cleaning function. Confirmed to be valid.

According to experiments, when back carbon paper sheets were fed with the carbon side facing toward the separation roller 6', dirt was removed due to the cooperative action of the grooves 31 of the pressure roller 28 and the foam holes on the surface of the separation roller 6'. It has been confirmed that almost no adhesion occurs.

It should be noted that the embodiments of the present invention are of course not limited to the above-mentioned embodiments. For example, a peeling roller may be provided below the feed roller, or a friction material made of a different material may be provided only on the contact peripheral surface of each roller. Various embodiments can be adopted, such as arranging a ring.

Further, the attached pair line device is not limited to facsimile machines, but can be widely applied to various electronic copying machines, printers, automatic document processing devices, etc.

〔Effect of the invention〕

According to the present invention, basically a toner original,
When feeding originals with image information such as pencil-written originals, back carbon paper originals, and originals with eraser scraps, etc., from the stacked tray, the separation roller and feed roller will remove carbon, correction liquid powder, rubber scraps, etc. over time. Therefore, there is no dirt on the rollers, the friction coefficient as designed is maintained, and the paper sheet is reliably rolled without jams, wrinkles, curls, or bends.
An excellent effect is produced as the sheets are fed one by one.

Therefore, it is possible to use back carbon paper, thin copy paper, and low-rigidity paper, which have been considered difficult in the past.

In this way, the pressure roller that is placed in front of the feed roller and is in pressure contact with the conveyance roller is formed so that the pressure contact surface that presses against the conveyance roller and the abutment circumferential surface that contacts the separation roller that engages with the feed roller are different in the axial direction. As a result, dirt on the document transferred to the conveyance roller is not transferred to the separation roller due to the cleaning and peeling action of the pressure roller, and dirt transferred to the feed roller is secondarily transferred to the separation roller. However, the cleaning and removal action is performed on the contact peripheral surface of the pressure roller against the separation roller, so that ping-pong transfer of dirt between the feed roller and the separation roller does not occur, the friction coefficient of the roller does not change, and the feed The effect that both the feeding action and the separating action of one sheet of paper are reliably maintained is achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a sheet feeding device based on the prior art, FIG. 2 and the following are explanatory views of embodiments of the present invention, FIG. 2 is a side view of one embodiment, and FIG. Side view of the support mechanism for the roller and pressure roller, No. 4
The figure is a perspective view of the paper sheet and the roller, FIG. 5 is a side view of the roller operation before feeding the paper sheet, FIG. 6 is a side view of the initial feeding of multiple sheets of paper, and FIG. 7 is a side view of the regular sheet feeding. Fig. 8 is a front view for explaining the engagement relationship between the pressure roller, the conveyance roller, and the separation roller. Fig. 9 is a front view corresponding to Fig. 8 of another embodiment. Figs. 10 to 13 are surface views of the surface friction coefficient forming portion of the roller. It is. 5... Paper sheet, 2'... Loading tray, 13... Drive device, 9'... Feed roller, 20... Conveyance roller, 6'... Separation roller, 28... Pressure roller,
11... Paper sheet feeding device, 30, 30'... Separation roller abutting circumferential surface, 29, 29'... Conveying roller abutting circumferential surface.

Claims (1)

[Scope of Claims] 1. A separation roller 6' is provided for each of the feed roller 9' and the conveyance roller 20, which are provided in front of the sheet stacking tray 2', arranged in the sheet forwarding direction, and linked to the drive device 13. In the sheet feeding device in which the pressure roller 28 is in contact with the pressure roller 28, the pressure roller 28 is disposed so as to be in contact with the separation roller 6', and the peripheral surface of the pressure roller 28 is in contact with the separation roller 6'. contact peripheral surface 30 with separation roller 6';
30' and the contact peripheral surface 29 of the conveyance roller 20,
29' are differently shaped, and the separation roller 6' receives the torque T _F due to contact with the feed roller 9' and the torque received from the contact peripheral surfaces 30, 30' with the pressure roller 28. Let T _M be the torque applied to the separation roller 6' from the paper when only one sheet is held between the separation roller 6' and the feed roller 9'.
T _P , when two sheets of paper enter and are held between the rollers, the frictional resistance between the sheets causes the paper to be transmitted from the feed roller 9' to the separation roller 6' via the sheet. When the torque is T _PP , the contact peripheral surfaces 30 and 3 of the separation roller 6', feed roller 9', and pressure roller 28 are adjusted so that the relationship T _F > T _P > T _M > T _PP is satisfied.
A friction coefficient of 0' is selected, and the pressure roller 28 has a contact peripheral surface 30 with the separation roller 6',
30' and the contact peripheral surface 29, 2 of the conveyance roller 20
A sheet feeding device characterized in that concave and convex portions 31, 31', 31'', and 31 are formed on 9'.