JP3561199B2 - Paper feed roller and method of manufacturing the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a paper feed roller used in a paper feed device of an OA device and a method of manufacturing the same.
[0002]
[Prior art]
A paper feed roller is used in a paper feeder of OA equipment such as a copying machine, a fax machine, a printer, and a plotter, and has a function of rotating in contact with a sheet to be sent out and sending out the sheet by a frictional force with the sheet. I have. The paper feeder includes a paper feed roller that directly contacts the paper, and a support that holds and rotates the paper feed roller. As the paper feed roller, a rubber material having a low hardness or the like is used, and a substantially cylindrical shape having a solid inside is often used. As the paper feed roller, a roller formed individually and fixed to a support, a roller formed by directly coating the support, and the like are used.
[0003]
By the way, the conventional paper feeding apparatus is liable to cause various paper feeding problems, such as the paper being fed while being overlapped, the paper being unable to follow the variation in the thickness of the paper, and being unable to be fed. In the case of multiple printing, the paper is moved for each color or for each writing order. However, the paper may not be moved accurately and a printing shift may occur.
[0004]
The main cause of the paper feed failure is often due to inappropriate elasticity of the paper feed roller. That is, the paper feed roller is a rubber material that is mainly solid inside, and even though it has low hardness, the degree of expansion and contraction of the portion that comes into contact with the paper varies with the thickness of the paper and the paper that is stacked at one time. It cannot be said that it sufficiently follows the overlap thickness, and the paper thickness compatibility is poor. Therefore, insufficient contact pressure and insufficient contact area with the paper occur, and various paper feeding problems occur.
[0005]
In addition, in order to ensure feeding, a large contact pressure with the sheet may be taken. In this case, if the paper feed roller is made of a rubber material that is solid to the inside, the elasticity is often insufficient, a strong frictional force acts on the paper contact surface, the paper surface is shaved and paper dust is generated, There was a problem of flying around.
[0006]
As a prior art addressing the above-mentioned problems, Japanese Patent Publication No. 2887041 is disclosed, which considerably solves the above-mentioned problems, but does not sufficiently solve the problems.
[0007]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feed roller which has high paper thickness compatibility and can reliably perform paper feed.
[0008]
Another object of the present invention is to provide a paper feed roller in which the contact pressure with the paper is strong and stable.
[0009]
Still another object of the present invention is to provide a paper feed roller having a large crushing amount and a high restoration followability.
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, a paper feed roller according to the present invention includes a paper contact portion and a support portion, and is entirely made of a material having rubber elasticity. The paper contact portion has a substantially cylindrical shape. The outer surface of the paper contact portion has internal stress in the direction of contraction, and the inner surface has internal stress in the direction of expansion. The support portion is integrally provided on both side surfaces of the paper contact portion.
[0011]
As described above, the paper feed roller according to the present invention has the internal stress in the direction in which the outer surface of the paper contact portion contracts and has the internal stress in the direction in which the inner surface expands. In a state where the stress and the internal stress in the direction in which the inner surface expands are balanced, the shape of the paper contact portion maintains a constant shape.
[0012]
When the paper is fed, the contact surface with the paper is deformed by the force from the out-of-plane direction, but as a force to return to the original shape, it works as a force to return the internal stress to the original balanced state, and Will increase the contact pressure. In addition, restoration followability such as restoration force and restoration speed of the paper contact portion after compression can be enhanced.
[0013]
Further, the support portion is integrally connected to the paper contact portion via a plate-shaped arc-shaped portion. Therefore, when the paper is fed, the arc-shaped portion is flexibly deformed by a load acting on the contact surface with the paper from the out-of-plane direction, so that the paper contact portion can be crushed deeply.
[0014]
Depending on the thickness of the paper and the thickness of the paper stacked at one time, a state of deep or shallow collapse may occur, but internal stress is always applied, so a stable contact pressure can be obtained. it can. As a result, the crushing amount is large, the restoration follow-up property is high, and the range of the paper thickness correspondence including the correspondence such as the overlapping thickness of the sheets is widened.
[0015]
Further, it is possible to prevent a problem that occurs when the elasticity is insufficient and a strong frictional force is applied to the paper contact surface to scrape the surface of the paper to generate paper dust and scatter around the paper. Further, since the arc-shaped portion is flexibly deformed, the problem that the contact pressure with the paper is particularly strong only in the vicinity of the support piece and local pressurization can be prevented.
[0016]
The method for manufacturing a paper feed roller according to the present invention includes a first step and a second step. Then, the compact obtained in the first step is turned upside down in the second step. Thereby, the paper feed roller according to the present invention is obtained.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a sectional view showing a paper feed roller according to the present invention. FIG. 2 is a side view of FIG. The paper feed roller 1 includes a paper contact part 5, a support part 7, a mounting hole 9, and a cavity 11.
[0018]
The paper feed roller 1 is made of a material having rubbery elasticity and is formed in a substantially cylindrical shape. Further, it has a shape symmetrical with respect to the rotation axis C.
[0019]
The paper contact section 5 has an outer surface 17 and an inner surface 15. The paper contact portion 5 forms an outer shell substantially along the circumference of the substantially cylindrical shape of the paper feed roller 1 having a diameter R1. The support portion 7 constitutes both sides of the substantially cylindrical shape of the paper feed roller 1, and is integrally connected to the paper contact portion 5 via an arc-shaped portion 13. The inner and outer surfaces of the arc-shaped portion 13 are an outer corner 14 and an inner corner 12, respectively. The mounting hole 9 passes through the center of the support 7. The cavity 11 is surrounded by the inner surface 15 and communicates with the mounting hole 9. The support portion reinforcement 19 is connected to the support portion 7 at a substantially right angle.
[0020]
One of the features of the present invention is that the paper contact portion 5 has internal stress. The paper contact portion 5 has an internal stress F1 in a direction contracting in a direction orthogonal to the circumferential direction ( a direction parallel to the rotation axis C) on the outer surface 17 and an internal stress F3 in a direction contracting in the circumferential direction, The inner surface 15 has an internal stress F2 extending in a direction perpendicular to the circumferential direction ( a direction parallel to the rotation axis C) and an internal stress F4 extending in the circumferential direction. The paper contact portion 5 maintains a constant shape in a state where the internal stresses F1 and F3 in the contracting direction and the internal stresses F2 and F4 in the expanding direction are balanced.
[0021]
FIG. 3 is a sectional view of a specific use example of the paper feed roller shown in FIG. In the figure, the paper feed roller 1 is assembled via a holding groove 43 provided in a support 41. Further, the support 41 is attached to a drive shaft 45, and the paper feed roller 1 can be rotated in the direction of arrow D by rotating the drive shaft 45. The paper feed roller 1 makes contact with the paper 47 and feeds the paper 47 while being rotated by the drive shaft 45.
[0022]
The drawing shows that the side where the paper feed roller 1 is in contact with the paper 47 is in a deeply crushed state. That is, the height H1 on the non-contact side is collapsed to the height H2 on the contact side. When the contact surface with the paper is deformed and crushed by the force F5 from the out-of-plane direction, a restoring force is generated in the paper contact portion 5 to return to the original shape based on the compression elastic force. The internal stress of the contact portion 5 acts as a force for returning to the original balanced state.
[0023]
This action increases the contact pressure with the paper 47. Further, restoration followability such as restoring force and restoring speed after deformation of the paper contact portion 5 can be improved.
[0024]
Further, the support portion 7 and the paper contact portion 5 are integrally connected via a plate-shaped arc-shaped portion 13. Therefore, the arc-shaped portion 13 flexibly deforms in response to a force F5 acting on the contact surface with the sheet 47 from the out-of-plane direction, so that the height H1 on the non-contact side is changed from the height H2 on the contact side. The amount of crushing can be large. Therefore, the paper contact portion 5 can be crushed deeply.
[0025]
In addition, since the support portion reinforcement 19 has a tip facing outward, the paper contact portion 5 including the arc-shaped portion 13 is deeply crushed and spreads in a direction parallel to the rotation axis C. Is pressed against the inner wall of the holding groove 43, so that the support reinforcement 19 does not rise from the holding groove 43.
[0026]
Also, the contact pressure between the deeply crushed state and the shallowly crushed state varies depending on the internal stress, so that the roller having the support portion 7 lacking the arc-shaped portion 13 or the cavity 11 Is smaller than a roller that is full of chips. Therefore, a stable contact pressure can be obtained with respect to the overlapping thickness of the sheets and the difference in the sheet thickness. As a result, the range of the paper thickness correspondence including the correspondence such as the overlapping thickness of the sheets is expanded. Further, since the elasticity is insufficient, a strong frictional force acts on the paper contact surface, so that the problem that the surface of the paper 47 is shaved and paper dust is generated and scatters around can be prevented.
[0027]
Further, since the arc-shaped portion 13 is flexibly deformed, it is possible to prevent local pressurization in which the contact pressure with the paper 47 acts particularly strongly near the support piece.
[0028]
Next, a method for manufacturing the paper feed roller according to the present invention will be described. FIG. 4 is a sectional view showing a primary molded product of the paper feed roller shown in FIG. 1, and FIG. 5 is a side view of FIG.
[0029]
As a method for manufacturing the paper feed roller 1, in the first step, a first molded product 3 is formed. The primary molded product 3 includes a primary outer peripheral portion 23, a primary side surface portion 25, a corner portion 31, and an opening 10. Further, there is also a portion serving as support portion reinforcement 19. The primary molded product 3 is made of a material having rubbery elasticity, and is integrally formed in a substantially cylindrical shape.
[0030]
The primary outer peripheral portion 23 forms an outer shell along a substantially cylindrical circumference. It also has an inner surface 27 having a maximum diameter R4 and an outer surface 29 having a maximum diameter R3. The primary side surface portion 25 constitutes a substantially cylindrical side surface on both sides, and is integrally connected to the primary outer peripheral portion 23 via a corner portion 31. The corner 31 has a primary entry corner 33 and a primary exit corner 35. The opening 10 passes through the center of the primary side surface portion 25.
[0031]
FIG. 6 is a cross-sectional view showing the process of turning the primary molded product of FIG. 4 upside down to form a paper feed roller. The upper part from the center line c shown by the one-dot chain line is given the same reference numeral as the reference numeral attached to the primary molded product 3 shown in FIG. 4, and the lower part from the center line c is the paper feed roller 1 shown in FIG. The same reference numerals as in FIG.
[0032]
In the secondary process, the inside surface 27 and the outside surface 29 of the primary outer peripheral portion 23 are turned inside out through the opening 10 as shown by arrows.
[0033]
When turned over, the inner surface 27 of the primary outer peripheral portion 23 becomes the outer surface 17 of the paper contact portion 5, and the outer surface 29 becomes the inner surface 15. That is, the outer surface 17 of the paper contact portion 5 of the paper feed roller 1 shown in FIG. 1 is used for the primary molded product 3 formed from the raw material by the primary processing to the inner surface 27 of the primary outer peripheral portion 23 at the time of the secondary processing. Is obtained by turning over the surface which has been described above through the opening 10.
[0034]
It is easy to turn this inside out. As described with reference to FIG. 4, the primary molded product 3 is made of a material having rubber elasticity, and is relatively free to expand and contract.
[0035]
The primary outer peripheral portion 23 has an inner surface 27 and an outer surface 29 and forms an outer shell along a substantially cylindrical circumference. The primary side surface portion 25 forms substantially cylindrical both side surfaces, and is integrally joined to the primary outer peripheral portion 23 via a corner portion 31. The opening 10 passes through the center of the primary side surface portion 25.
[0036]
Therefore, the opening 10 may be pushed open, and the other primary side surface portion 25 may be passed through the opening 10. After that, since the primary side surface portion 23 and the primary outer peripheral portion 25 are integrally joined via the corner portion 31, the primary outer peripheral portion 23 integrally provided is continuously turned over and the paper feed roller is turned over. It takes the form of 1.
[0037]
Each part of the primary molded article 3 and the paper feed roller 1 obtained by turning over will be compared. First, the support portion reinforcement 19 that has protruded inside has a shape protruding outside. The primary entry corner 33 of the primary molded article 3 is the exit corner 14 of the paper feed roller 1, while the primary exit corner 35 of the primary molded article 3 is the entry corner 12 of the paper feed roller 1 and is turned over. This causes an inversion phenomenon in which the inside corner and the outside corner are switched. This reversal phenomenon is that the corner portion 31 is inverted and the primary outer peripheral portion 23 is also turned over because the corner portion 31 has an arc shape and has a plate shape. Next, the phenomenon caused by the exchange of the inner and outer surfaces will be examined.
[0038]
The circumferential length of the inner surface 27 and the outer surface 29 of the primary molded article 3 shown in FIGS. 4 and 5 will be compared. Since the respective lengths are the inner surface and the outer surface of the cylindrical shape, the length is substantially proportional to the diameter R4 of the inner surface 27 and the diameter R3 of the outer surface 29. Since the diameter R3 is larger than the diameter R4, the length of the outer surface 29 is naturally larger.
[0039]
On the other hand, comparing the circumferential lengths of the inner surface 15 and the outer surface 17 of the paper feed roller 1 shown in FIGS. 1 and 2, the diameter of the outer surface 17 is the same as that of the primary molded product 3 in FIG. Since R1 is larger than the diameter R2 of the inner surface 15, it is obvious that the length of the outer surface 17 is longer than the length of the inner surface 15.
[0040]
Since the inner and outer surfaces of the primary molded product 3 are replaced with each other, the inner surface 27 of the primary molded product 3 having a shorter length is replaced with the outer surface 17 having a longer paper feed roller. Thereby, the outer surface 17 is in a state of being extended in the circumferential direction.
[0041]
On the other hand, the longer outer surface 29 of the primary molded product 3 is used as the inner surface 15 having the shorter length of the paper feed roller, so that the inner surface 15 is contracted in the circumferential direction.
[0042]
For this reason, a force F3 for shrinking the outer surface 17 always works, and a force F4 for expanding the inner surface 15 always works. The internal stresses F3 and F4 are always stored in the paper contact portion 5 of the paper feed roller 1. This internal stress effectively acts on the paper thickness correspondence and restoration followability as the paper feeding function.
[0043]
Inverting the surface that was the inner surface 27 of the primary outer peripheral portion 23 is performed because the primary outer peripheral portion 23 and the primary side surface portion 25 are formed into an integral substantially cylindrical shape. Will also be turned over. As described above, since the sheet including the primary side surface portion 25 is turned over, the tensile force and the compressive force acting on the paper contact portion 5 act not only in the circumferential direction but also in the rotational axis C direction. Therefore, the internal stress acts on both the circumferential direction F3 and F4 and the rotational axis C direction F1 and F2 shown in FIGS.
[0044]
FIG. 7 is a sectional view showing another embodiment of the primary molded product according to the present invention and the paper feed roller based thereon. In the figure, a primary molded product 3 is made of a material having rubbery elasticity, and is molded in a substantially cylindrical shape. In addition, it includes a primary outer peripheral portion 23, a primary side surface portion 25, and an opening 10. Further, the primary outer peripheral portion 23 has an inner surface 27 and an outer surface 29.
[0045]
The paper feed roller 1 is obtained by turning the primary molded product 3 upside down, and includes a paper contact portion 5, a support portion 7, a mounting hole 9, a cavity 11, an arc-shaped portion 13, and a support portion reinforcement 19.
[0046]
When the primary molded product 3 is turned over, the joint between the primary outer peripheral portion 23 and the primary side surface portion 25 has a bent corner shape, and forms a primary entry corner 33 and a primary exit corner 35. ing. Therefore, since this portion is not an arc shape like the primary entry corner 33 and the primary exit corner 35 of the corner portion 31 shown in FIG. 4, the inversion that the exit corner and the entrance corner are switched does not occur.
[0047]
When the primary outer peripheral portion 23 is turned over, the non-reversed primary entry corner 33 and primary exit corner 35 restrain the deformation of the primary outer peripheral portion 23, and the paper feed roller 1 moves left and right as shown in the figure. The arc-shaped portion 13 and the paper contact portion 5 have a semicircular shape as a whole, and have a U-shaped protruding center.
[0048]
The following is a comparison between the primary molded product 3 and each part of the paper feed roller 1. First, the primary outer peripheral portion 23 of the primary molded product 3 becomes the paper contact portion 5, the arc-shaped portion 13, and the support portion 7 of the paper feed roller 1. Further, a primary side surface portion 25 of the primary molded product 3 serves as a support portion reinforcement 19 of the paper feed roller 1.
[0049]
Further, the outer surface 17 and the inner surface 15 of the paper feed roller 1 are obtained by turning the inner surface 27 and the outer surface 29 of the primary outer peripheral portion 23 of the primary molded product 3 through the opening 10, respectively. .
[0050]
In addition, since the primary outer peripheral portion 23 having the length L1 is formed as the outer surface 17 having the length L2 and the inner surface 15 having the length L3 in the paper contact portion 5, the outer surface 17 and the inner surface 15 have the rotation axis C direction. The internal stress F1 in the direction of contraction and the internal stress F2 in the direction of expansion are stored.
[0051]
Comparing the performance of the paper feed roller 1 of FIG. 1 with that of the paper feed roller 1 of FIG. 7, the paper feed roller 1 of FIG. The range of paper thickness compatibility also expands.
[0052]
FIG. 8 is a sectional view showing still another embodiment of the primary molded product according to the present invention and the paper feed roller based thereon. The same components as those shown in FIG. 7 are denoted by the same reference numerals.
[0053]
The primary molded product 3 is different from the primary molded product 3 shown in FIG. 6 in that the primary side surface portion 25 projects outward from the outer surface 29 of the primary outer peripheral portion 23.
[0054]
By extending the primary side surface portion 25 outward from the outer surface 29, the support portion reinforcement 19 of the paper feed roller 1 obtained by turning over the primary molded product 3 can be prevented from going outside. By doing so, the fit and design when the paper feed roller 1 is attached are improved.
[0055]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
(A) It is possible to provide a paper feed roller having a high paper thickness compatibility and capable of reliably performing paper feed.
(B) It is possible to provide a paper feed roller in which the contact pressure with the paper is strong and stable.
(C) It is possible to provide a paper feed roller having a large crushing amount and a high restoration followability.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a paper feed roller according to the present invention.
FIG. 2 is a side view of FIG.
FIG. 3 is a sectional view of a specific example of use of the paper feed roller shown in FIG. 1;
FIG. 4 is a cross-sectional view showing a primary molded product of the paper feed roller shown in FIG.
FIG. 5 is a side view of the paper feed roller shown in FIG.
FIG. 6 is a cross-sectional view showing the process of turning the primary molded product of FIG. 4 upside down to form a paper feed roller.
FIG. 7 is a cross-sectional view showing another embodiment of a primary molded product and a paper feed roller obtained by the manufacturing method according to the present invention.
FIG. 8 is a sectional view showing still another embodiment of a primary molded product and a paper feed roller obtained by the manufacturing method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper feed roller 5 Paper contact part 7 Support part 9 Mounting hole 10 Opening 11 Cavity 15 Inner surface 17 Outer surface 41 Support

Claims (1)

A method for manufacturing a paper feed roller, comprising:
The paper feed roller includes a paper contact portion and a support portion, and is entirely made of a rubbery elastic material,
The paper contact portion has a substantially cylindrical shape, the outer surface has internal stress in the direction of contraction, the inner surface has internal stress in the direction of expansion,
The support portion is integrally provided on both side surfaces of the paper contact portion , and has support portion reinforcement at both end edges,
The support portion reinforcement is connected to the support portion at a substantially right angle in an outward direction,
The method of manufacturing the paper feed roller includes a primary step and a secondary step,
The primary step is a step of forming a primary molded product used for the paper feed roller,
The primary molded product includes a primary outer peripheral portion, a primary side surface portion, a corner portion, an opening, and a portion for reinforcing the support portion, and is formed into a substantially cylindrical shape,
The primary outer peripheral portion constitutes an outer shell along a substantially cylindrical circumference,
The primary side surface portion constitutes a substantially cylindrical side surface on both sides, and is integrally connected to the primary outer peripheral portion via the corner portion,
The opening penetrates the center of the primary side surface portion,
The portion serving as the support portion reinforcement is connected to the support portion at a substantially right angle in the inward direction,
The method of manufacturing a paper feed roller, wherein the secondary step includes a step of turning over the primary molded product.

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