CN102120532A - Friction wheel and friction wheel module using same - Google Patents

Abstract

The present invention relates to a friction wheel and a friction wheel module using the same, which is used in an automatic paper feeder to provide a frictional force for separating documents. The friction wheel can generate a first damping torque and a second damping torque which are opposite in direction, and the second damping torque is smaller than the first damping torque so as to reduce the friction resistance suffered by the document when the document exits the automatic paper feeder. Compared with the friction wheel of the existing automatic paper feeder, the friction wheel is more convenient to disassemble and assemble, the friction wheel of the existing automatic paper feeder only allows the document to move in the paper feeding direction, the friction wheel also allows the document to move in the paper withdrawing direction, and when a paper jam occurs, a user can take out the document without opening the upper cover of the automatic paper feeder.

Description

Friction wheel and friction wheel module using the friction wheel

technical field

The invention relates to a friction wheel, in particular to a friction wheel applied in an automatic document feeder.

Background technique

Early scanning devices can only scan the image of a single document. When a user wants to scan a double-sided document, the document must be turned over manually so that the scanning device can scan the image on the other side of the document. And when the user wants to scan a stack of documents, he must take out the scanned document after the scanning device scans a document and place the next document on the scanning device to scan the next document. Because it is too troublesome to manually turn over and replace documents, an automatic document feeder has been developed on the market. When used with a scanning device, it can complete double-sided scanning and scan multiple documents without manual turning.

Generally speaking, the automatic document feeder is equipped with a paper-feeding module, which is used to move a stack of documents from the paper tray where the documents are placed and move in a paper feeding direction to enter the automatic document feeder. During the document feeding process, In order to ensure that only one document is fed into the automatic document feeder each time, in addition to setting a paper separation roller in the paper pickup module, it is also necessary to install a friction plate under the paper separation roller, which can provide friction and friction The documents in contact with the sheet, so that the friction between the document in contact with the paper module and the paper module is greater than the friction between the documents, and the friction between the document and the friction sheet in contact with the friction sheet is also greater than the friction between the files. to ensure that only one document is fed into the ADF at a time. With the prolongation of the use time of the automatic document feeder, the friction plate also wears out thereupon, so that the friction plate cannot ensure the paper separation function, so the friction plate must be replaced, and the known friction plate is locked on the automatic document feeder , quite inconvenient when replacing the friction plate.

In view of this, U.S. Patent No. 6,659,450 discloses an automatic document feeder that facilitates the removal of friction plates and friction wheels. When the document is fed, the friction wheel generates a damping torque in the direction of the paper feeding rotation, thereby providing a frictional force to the document. Although the friction plate and the friction wheel disclosed in the automatic document feeder disclosed in U.S. Patent No. 6,659,450 are easier to disassemble than the known friction plate, after the friction wheel is disassembled, the spring that provides the friction wheel with a positive force is still left in the automatic paper feeder. In the device, when assembling the friction wheel, the user must assemble the friction wheel on the automatic document feeder, and at the same time align the friction wheel with the spring to combine the friction wheel and the spring to make the friction wheel work normally. Such an assembly method Too inconvenient.

In addition, when jamming occurs in the automatic document feeder, due to the friction wheel or friction plate, when the user wants to pull out the jammed document from the automatic document feeder, the document and the friction wheel or The friction sheet is in contact and has friction, so the user cannot directly move the document to the direction opposite to the feeding direction-the ejecting direction and pull it out of the automatic document feeder, but must open the upper cover of the automatic document feeder. The document can be taken out only when the paper-taking module is away from the document and the document is not in contact with the friction wheel or the friction plate without friction. In view of the complexity of how to take out documents from the automatic document feeder, there is a need for a friction wheel that can move the documents in the direction of feeding and unloading, so that the user can take out the documents without opening the upper cover.

Contents of the invention

The object of the present invention is to provide a friction wheel that can move the document in the paper feeding direction and the paper ejecting direction.

Another object of the present invention is to provide a friction wheel module that is convenient for disassembly and assembly.

In a preferred embodiment, the present invention provides a friction wheel applied to an automatic document feeder to provide a frictional force for separating a first document from a second document, wherein the second document is located on the first document A top file, the friction wheel consists of:

a sleeve having a sleeve inner wall;

a friction pad surrounds the sleeve for contacting the second document;

A coil spring is arranged in the sleeve, the coil spring has a first spring part and a second spring part, and the first spring part has a first spring inner diameter, and the second spring part has a diameter smaller than the first spring part a second spring inner diameter of the spring inner diameter, the first spring portion in contact with the inner wall of the sleeve; and

A wheel shaft passes through the coil spring and contacts with the second spring portion; wherein when the second file moves in a first direction, the sleeve rotates in a first rotation direction, and the first spring portion is moved toward the The first rotation direction is twisted to expand the first spring inner diameter of the first spring part, so that the first spring part is fixed by the inner wall of the sleeve, and the second spring part is twisted relative to the axle to generate a first damping torque ; when the inner diameter of the first spring of the first spring portion expands, and the second file moves in a second direction opposite to the first direction, the sleeve rotates in a second rotation direction, and the second The spring part is fixed on the axle, and the first spring part is twisted to generate a second damping torque; wherein the first damping torque is greater than the second damping torque.

In a preferred embodiment, a first inner wall portion of the inner wall of the sleeve has a first inner diameter of the sleeve, and the first inner wall portion is close to one end of the sleeve, and a second inner wall of the inner wall of the sleeve The portion has a second sleeve inner diameter, and the second inner wall portion is close to the other end of the sleeve; wherein the first sleeve inner diameter is smaller than the second sleeve inner diameter.

In a preferred embodiment, the inner wall of the sleeve is an inclined inner wall.

In a preferred embodiment, the first spring part is in contact with the first inner wall part, the second spring part is not in contact with the second inner wall part but is in contact with the axle, when the sleeve moves in the first rotation direction Rotate, the first spring part is twisted to the first rotation direction to expand the first spring inner diameter of the first spring part, so that the first spring part is fixed by the first inner wall part, and the second spring part is relatively The axle is twisted to generate the first damping torque; when the inner diameter of the first spring of the first spring portion expands and the second file moves in the second direction, the sleeve rotates in a second rotation direction , the second spring part is fixed by the axle, and the first spring part is twisted to generate the second damping torque.

In a preferred embodiment, the first spring part is eccentrically connected to the second spring part.

In a preferred embodiment, the friction wheel of the present invention further includes an accommodating shaft extending into the end of the sleeve for accommodating the axle when the axle extends into the other end of the sleeve.

In a preferred embodiment, the present invention also provides a friction wheel, which is applied to an automatic document feeder to provide a frictional force for separating a first document from a second document, wherein the second document is located on the Above the first file, the friction wheel consists of:

a first sleeve having a sleeve inner tube;

a second sleeve, arranged in the first sleeve, and the second sleeve has a sleeve outer tube, located at one end of the second sleeve, for contacting with one end of the sleeve inner tube;

a friction pad surrounds the first sleeve for contacting the second document;

A coil spring is arranged in the first sleeve, one end of the coil spring is sleeved on the outer tube of the sleeve to form a first spring portion, and the other end of the coil spring is sleeved in the inner tube of the sleeve A second spring portion is formed on the top, and the first spring portion has a first spring inner diameter, and the second spring portion has a second spring inner diameter smaller than the first spring inner diameter;

a one-way clutch, disposed in the second sleeve, for preventing the second sleeve from rotating in a first rotational direction; and

A wheel shaft passes through the first sleeve, the second sleeve and the one-way clutch; wherein when the second file moves in a first direction, the first sleeve rotates in the first rotation direction, and the The second sleeve is constrained by the one-way clutch and cannot rotate, so that the first spring part is fixed on the outer tube of the sleeve, and the second spring part is twisted relative to the inner tube of the sleeve to generate a first damping Torque; when the second file moves in a second direction opposite to the first direction, the first sleeve rotates in a second rotation direction, the first spring portion is fixed on the outer tube of the sleeve, And the second spring part is fixed on the inner tube of the sleeve, so that the second sleeve rotates with the rotation of the first sleeve, and the one-way clutch rotates relative to the axle to generate the second Damping torque; wherein the first damping torque is greater than the second damping torque.

In a preferred embodiment, the diameter of the inner tube of the sleeve is smaller than the diameter of the outer tube of the sleeve, so that the interference between the first spring part and the outer tube of the sleeve is larger than that between the second spring part and the outer tube of the sleeve. The amount of interference between the tubes in the sleeve.

In a preferred embodiment, the present invention also provides a friction wheel module using a friction wheel, which is applied to an automatic document feeder to provide friction for separating a first document and a second document, wherein the The second file is located above the first file, the friction wheel module includes:

a friction wheel bracket;

A friction wheel is arranged on the friction wheel bracket, and the friction wheel includes:

a sleeve having a sleeve inner wall;

a friction pad surrounds the sleeve for contacting the second document;

A coil spring is arranged in the sleeve, the coil spring has a first spring part and a second spring part, and the first spring part has a first spring inner diameter, and the second spring part has a diameter smaller than the first spring part a second spring inner diameter of the spring inner diameter, the first spring portion in contact with the inner wall of the sleeve; and

A wheel shaft passes through the coil spring and contacts with the second spring portion; wherein when the second file moves in a first direction, the sleeve rotates in a first rotation direction, and the first spring portion is moved toward the The first rotation direction is twisted to expand the first spring inner diameter of the first spring part, so that the first spring part is fixed by the inner wall of the sleeve, and the second spring part is twisted relative to the axle to generate a first damping torque ; when the inner diameter of the first spring of the first spring portion expands, and the second file moves in a second direction opposite to the first direction, the sleeve rotates in a second rotation direction, and the second the spring part is fixed on the axle, and the first spring part is twisted to generate a second damping torque; wherein the first damping torque is greater than the second damping torque; and

An elastic element is arranged on the friction wheel support and is in contact with the friction wheel to provide an elastic force to the friction wheel to move the friction wheel up and down relative to the friction wheel support.

In a preferred embodiment, a first inner wall portion of the inner wall of the sleeve has a first inner diameter of the sleeve, and the first inner wall portion is close to one end of the sleeve, and a second inner wall of the inner wall of the sleeve The portion has a second sleeve inner diameter, and the second inner wall portion is close to the other end of the sleeve; wherein the first sleeve inner diameter is smaller than the second sleeve inner diameter.

In a preferred embodiment, the inner wall of the sleeve is an inclined inner wall.

In a preferred embodiment, the first spring part is in contact with the first inner wall part, the second spring part is not in contact with the second inner wall part but is in contact with the axle, when the sleeve moves in the first rotation direction Rotate, the first spring part is twisted to the first rotation direction to expand the first spring inner diameter of the first spring part, so that the first spring part is fixed by the first inner wall part, and the second spring part is relatively The axle is twisted to generate the first damping torque; when the inner diameter of the first spring of the first spring portion expands and the second file moves in the second direction, the sleeve rotates in a second rotation direction , the second spring part is fixed by the axle, and the first spring part is twisted to generate the second damping torque.

In a preferred embodiment, the first spring part is eccentrically connected to the second spring part.

In a preferred embodiment, the friction wheel module of the present invention further includes an accommodating shaft extending into the end of the sleeve for accommodating the wheel shaft when the wheel shaft extends into the other end of the sleeve.

In a preferred embodiment, the elastic element further includes a torsion spring arm, which is used to contact the friction wheel to provide the elastic force to the axle, so that the friction wheel moves up and down relative to the friction wheel bracket.

In a preferred embodiment, the elastic element is a supporting torsion spring.

In a preferred embodiment, the wheel shaft further includes a limiting edge for fixing to the friction wheel bracket, so that the wheel shaft is fixed and cannot rotate.

In a preferred embodiment, the present invention also provides a friction wheel module using a friction wheel, which is applied to an automatic document feeder to provide friction for separating a first document and a second document, wherein the The second file is located above the first file, the friction wheel module includes:

a friction wheel bracket;

A friction wheel is arranged on the friction wheel bracket, and the friction wheel includes:

a first sleeve having a sleeve inner tube;

a second sleeve, arranged in the first sleeve, and the second sleeve has a sleeve outer tube, located at one end of the second sleeve, for contacting with one end of the sleeve inner tube;

a friction pad surrounds the first sleeve for contacting the second document;

A coil spring is arranged in the first sleeve, one end of the coil spring is sleeved on the outer tube of the sleeve to form a first spring portion, and the other end of the coil spring is sleeved in the inner tube of the sleeve A second spring portion is formed on the top, and the first spring portion has a first spring inner diameter, and the second spring portion has a second spring inner diameter smaller than the first spring inner diameter;

a one-way clutch, disposed in the second sleeve, for preventing the second sleeve from rotating in a first rotational direction; and

A wheel shaft passes through the first sleeve, the second sleeve and the one-way clutch; wherein when the second file moves in a first direction, the first sleeve rotates in the first rotation direction, and the The second sleeve is constrained by the one-way clutch and cannot rotate, so that the first spring part is fixed on the outer tube of the sleeve, and the second spring part is twisted relative to the inner tube of the sleeve to generate a first damping Torque; when the second file moves in a second direction opposite to the first direction, the first sleeve rotates in a second rotation direction, the first spring portion is fixed on the outer tube of the sleeve, And the second spring part is fixed on the inner tube of the sleeve, so that the second sleeve rotates with the rotation of the first sleeve, and the one-way clutch rotates relative to the axle to generate the second damping torque; wherein the first damping torque is greater than the second damping torque; and

An elastic element is arranged on the friction wheel support and is in contact with the friction wheel to provide an elastic force to the friction wheel to move the friction wheel up and down relative to the friction wheel support.

In a preferred embodiment, the diameter of the inner tube of the sleeve is smaller than the diameter of the outer tube of the sleeve, so that the interference between the first spring part and the outer tube of the sleeve is larger than that between the second spring part and the outer tube of the sleeve. The amount of interference between the tubes in the sleeve.

In a preferred embodiment, the wheel shaft further includes a limiting edge for fixing to the friction wheel bracket, so that the wheel shaft is fixed and cannot rotate.

In a preferred embodiment, the elastic element further includes a torsion spring arm, which is used to contact the friction wheel to provide the elastic force to the axle, so that the friction wheel moves up and down relative to the friction wheel bracket.

In a preferred embodiment, the elastic element is a supporting torsion spring.

Compared with the friction wheel of the existing automatic document feeder, this friction wheel is easier to disassemble and assemble, and the friction wheel of the existing automatic document feeder only allows the document to move in the paper feeding direction, and this friction wheel It also allows the document to move in the paper ejecting direction. When a paper jam occurs, the user can take out the document without opening the upper cover of the automatic document feeder.

Description of drawings

Fig. 1 is a side view of the structure of the friction wheel module in the first preferred embodiment of the present invention when it is in the paper feeding state.

Fig. 2 is a three-dimensional exploded view of the structure of the friction wheel module in the first preferred embodiment of the present invention.

Fig. 3 is a schematic structural view of the friction wheel module in the first preferred embodiment of the present invention.

Fig. 4 is a cross-sectional view of the structure of the friction wheel in the first preferred embodiment of the present invention.

Fig. 5 is a side view of the structure of the friction wheel module in the first preferred embodiment of the present invention when it is in the paper ejecting state.

6A, 6B and 6C are schematic structural diagrams of disassembly/assembly of the friction wheel module in the first preferred embodiment of the present invention.

Fig. 7 is a cross-sectional view of the structure of the friction wheel in the second preferred embodiment of the present invention.

FIG. 8 is a three-dimensional exploded view of the structure of the friction wheel module in the third preferred embodiment of the present invention.

FIG. 9 is a cross-sectional view of the structure of the friction wheel module in the third preferred embodiment of the present invention.

Wherein, the reference signs are explained as follows:

1 automatic document feeder 10, 30 friction wheel module

20 Paper picking mechanism 101, 301 friction wheel bracket

102, 202, 302 friction wheel 103, 303 elastic element

1021, 2021, 3021, 3022 sleeve 1022, 2022, 3023 friction pad

1023, 2023, 3024 coil spring 1024, 2024, 3026 axle

2025 accommodate shaft 3025 one-way clutch

10241, 30261 limit edge 20211 first sleeve part

20212 Second sleeve part 30211 Sleeve inner tube

30221 sleeve outer tube A1, A2 direction

C1, C2 rotation direction d1, d2 sleeve inner diameter

d1’, d2’ pipe diameter r1, r2, r1’, r2’ spring inner diameter

S 1, S2 file T1, T2 damping torque

10231, 20231, 30241 first spring part

10232, 20232, 30242 second spring part

Detailed ways

The invention provides a friction wheel module applied in an automatic document feeder. Please refer to FIG. 1 , which is a side view of the structure of the friction wheel module in the first preferred embodiment of the present invention when it is in a paper feeding state. Fig. 1 shows that the friction wheel module of the present invention is arranged in an automatic document feeder 1, and the automatic document feeder 1 comprises a friction wheel module 10 and a paper fetching mechanism 20, and the paper fetching mechanism 20 is used for a first document S1 and A second document S2 is fed into the automatic document feeder 1 , and the friction wheel module 10 is used to provide a frictional force to the second document S2 to separate the first document S1 above the second document S2 from the second document S2 .

Next, the structure of the friction wheel module 10 will be described. Please refer to FIG. 2 and FIG. 3 at the same time. FIG. 2 is a three-dimensional exploded view of the structure of the friction wheel module in the first preferred embodiment of the present invention, and FIG. 3 is the friction wheel module of the present invention. Schematic diagram of the structure in the first preferred embodiment. The friction wheel module 10 includes a friction wheel bracket 101 , a friction wheel 102 and an elastic element 103 . The friction wheel bracket 101 is used to place the friction wheel 102, and the elastic element 103 is arranged on the friction wheel bracket 101 and is in contact with the friction wheel 102 to provide an elastic positive force to the friction wheel 102, so that the friction wheel 102 is relative to the friction wheel bracket 101 moves up and down, and in this preferred embodiment, the elastic element 103 is a supporting torsion spring.

As for the structure of the friction wheel 102 , please refer to FIG. 4 , which is a cross-sectional view of the structure of the friction wheel in the first preferred embodiment of the present invention. The friction wheel 102 disposed on the friction wheel bracket 101 includes a sleeve 1021 , a friction pad 1022 , a coil spring 1023 and a wheel axle 1024 . The sleeve 1021 has a sleeve inner wall 10211. The friction pad 1022 surrounds the sleeve 1021 for contacting with the second document S2 to provide friction. In this preferred embodiment, the friction pad 1022 is a rubber tire. The coil spring 1023 is disposed in the sleeve 1021, the coil spring 1023 has a first spring part 10231 and a second spring part 10232, and the first spring part 10231 has a first spring inner diameter r1, and the second spring part 10232 has a first spring part 10232 The second spring inner diameter r2, the first spring part 10231 is in contact with the sleeve inner wall 10211, while the second spring part 10232 is not in contact with the sleeve inner wall 10211, wherein the second spring inner diameter r2 is smaller than the first spring inner diameter r1, and the first spring part 10231 It is eccentrically connected to the second spring part 10232 . The wheel shaft 1024 passes through the coil spring 1023 and is in contact with the supporting torsion spring 103 to receive the elastic positive force from the supporting torsion spring 103, and the wheel shaft 1024 also includes a limiting edge 1024 for being fixed on the friction wheel bracket 101, so that the wheel shaft 1024 It is fixed and cannot rotate, as shown in Figure 2 and Figure 3.

Please refer to FIG. 1 again, when the automatic document feeder 1 intends to feed the first document S1 and the second document S2, the pick-up roller and the paper-separation roller of the pick-up mechanism 20 rotate to a second rotation direction C2 to feed the first document S1 and the second file S2 to make the first and second files S1, S2 move to a first direction A1, the friction pad 1022 of the friction wheel 102 is in contact with the second file S2 and is rotated, wherein the friction wheel 102 moves toward the second file S2 A first rotational direction C1 opposite to the rotational direction C2 rotates. In this preferred embodiment, the first direction A1 is a paper feeding direction, the first rotation direction C1 is a counterclockwise direction, and the second rotation direction C2 is a clockwise direction. When the first document S1 and the second document S2 are fed and move toward the first direction A1, the first document S1 and the second document S2 will abut against the friction wheel 102, so that the friction wheel 102 moves downward relative to the friction wheel support 101 , the first document S1 and the second document S2 enter the interior of the automatic document feeder 1 through the paper picking mechanism 20 and the friction wheel module 10 .

When the friction wheel 102 rotates in the first rotation direction C1 due to the contact between the friction pad 1022 and the second document S2, the sleeve 1021 of the friction wheel 102 also rotates in the first rotation direction C1, and the first rotation direction C1 in contact with the sleeve inner wall 10211 The spring part 10231 is twisted in the first rotation direction C1 by the rotating sleeve inner wall 10211, and the first spring part 10231 is expanded due to the rotation direction of the coil spring 1023, so that the inner diameter of the first spring part 10231 is expanded to be larger than the original first rotation direction C1. A spring inner diameter r1. At this time, the gap between the first spring part 10231 and the sleeve inner wall 10211 is reduced (that is, the interference between the first spring part 10231 and the sleeve inner wall 10211 is increased), so that the first spring part 10231 is fixed (tightly beam on) and the inner wall of the sleeve 10211. At the same time, the second spring part 10232 is twisted relative to the axle 1024, and the second spring part 10232 must overcome the internal stress generated by the interference between the second spring part 10232 and the axle 1024 to generate the first damping torque T1. Therefore, the friction wheel 102 provides a first friction force corresponding to the first damping torque T1 to the second document S2, so that the second document S2 cannot be fed, and at the same time, the first document S1 is fed by the paper picking module 20 to the first Move in direction A1.

Next, please refer to FIG. 5 , which is a side view of the structure of the friction wheel module in the first preferred embodiment of the present invention when it is in the paper ejecting state. When the first document S1 is fed into the automatic document feeder 1 and a paper jam occurs, the first document S1 must be taken out from the automatic document feeder 1, generally by moving the first document S1 in the direction opposite to the first direction A1. Move in the second direction A2 so as to take out the first document S1. In this preferred embodiment, the second direction A2 is a paper ejecting direction. When the first document S1 moves in the second direction A2, the friction wheel 102 rotates in the second direction of rotation C2 due to the contact of the friction pad 1022 with the second document S2, and the sleeve 1021 of the friction wheel 102 also moves in the second direction of rotation C2 Rotate, the second spring part 10232 is fixed (tightly bound) on the axle 1024 due to the helical direction of the coil spring 1023, and the first spring part 10231 in contact with the sleeve inner wall 10211 also follows the rotation of the sleeve inner wall 10211 The rotation is twisted in the second rotation direction C2, and the first spring part 10231 must overcome the internal stress generated by the interference between the first spring part 10231 and the sleeve inner wall 10211 to generate the second damping torque T2. Therefore, the friction wheel 102 provides a second frictional force to the second file S2. Since the interference between the first spring part 10231 and the sleeve inner wall 10211 is quite small, the second damping torque T2 is relatively small, so it corresponds to the second The second friction force of the damping torque T2 is also relatively small, so that the second document S2 can be taken out from the automatic document feeder 1 without being affected by too much resistance when it is moved in the second direction A2.

It should be noted that the damping torque is proportional to the friction force, that is, the greater the first damping torque T1, the greater the first friction force; on the contrary, the smaller the second damping torque T2, the greater the second friction force smaller.

Next, please refer to FIG. 6A , FIG. 6B and FIG. 6C in sequence, which are schematic structural diagrams of disassembly/assembly of the friction wheel module in the first preferred embodiment of the present invention. When the user wants to remove the friction wheel module 10 from the automatic document feeder 1 , he only needs to hold the two sides of the friction wheel 102 and turn over the friction wheel module 10 to remove the friction wheel module 10 . On the contrary, when the user wants to assemble the friction wheel module 10 on the automatic document feeder 1, it only needs to follow the sequence of FIG. 6C , FIG. 6B to FIG. 6A to assemble.

In addition, the present invention also provides a second preferred embodiment of the friction wheel and the friction wheel module, please refer to FIG. 7 , which is a structural sectional view of the friction wheel in the second preferred embodiment of the present invention. The second preferred embodiment of the present invention is mostly the same as the first preferred embodiment, the difference lies in the internal structure of the friction wheel 202, the friction wheel 202 includes a sleeve 2021, a friction pad 2022, a coil spring 2023, a The axle 2024 and a receiving axle 2025 . The sleeve 2021 has a first inner wall part 20211 and a second inner wall part 20212, and the first inner wall part 20211 has a first sleeve inner diameter d1, and the first inner wall part 20211 is close to one end of the sleeve 2021, and the second The inner wall portion 20212 has a second sleeve inner diameter d2, and the second inner wall portion 20212 is close to the other end of the sleeve 2021, and the first sleeve inner diameter d1 is smaller than the second sleeve inner diameter d2, wherein the inner wall of the sleeve 2021 is a The inclined inner wall is similar to the tapered inner wall.

The friction pad 2022 surrounds the sleeve 2021 for contacting with the second document S2 to provide friction. In this preferred embodiment, the friction pad 2022 is also a rubber tire. The coil spring 2023 is disposed in the sleeve 2021. The coil spring 2023 has a first spring part 20231 and a second spring part 20232, and the first spring part 20231 has a first spring inner diameter r1, and the second spring part 20232 has a first spring part 20232. Two spring inner diameter r2, the first spring part 20231 is in contact with the first inner wall part 20211, while the second spring part 20232 is not in contact with the second inner wall part 20212, wherein the second spring inner diameter r2 is smaller than the first spring inner diameter r1, and the first spring The part 20231 is eccentrically connected to the second spring part 20232 . The axle 2024 passes through the coil spring 2023 and the axle 2024 protrudes therein from the other end of the sleeve 2021 , while the accommodating axle 2025 protrudes from the other end of the sleeve 2021 and can accommodate the axle 2024 .

Next, the working situation of the friction wheel 202 will be described when the automatic document feeder is carrying out the paper feeding operation, and other elements in the automatic document feeder except the work of the friction wheel are all the same as those of the first preferred embodiment, so no further explanation will be given. . When the first document and the second document are fed, the friction wheel 202 rotates toward the first rotation direction due to the contact of the friction pad 2022 with the second document, and the sleeve 2021 of the friction wheel 202 also rotates toward the first rotation direction, and with the second rotation direction. The first spring part 20231 contacted by an inner wall part 20211 is twisted and expanded in the first rotation direction by the first inner wall part 20211 being rotated, so that the first spring part 20231 is fixed on the first inner wall part 20211, and the second spring part 20232 It is twisted relative to the axle 2024, and the second spring part 20232 must overcome the internal stress generated by the interference between the second spring part 20232 and the axle 2024 to generate the first damping torque. Therefore, the friction wheel 202 provides the first frictional force corresponding to the first damping torque to the second document, so that the second document cannot be fed, while the first document is fed by the pickup module 20 and moves in the first direction.

When the first document is fed into the automatic document feeder and a paper jam occurs, the first document must be removed from the automatic document feeder. When the first document moves in a second direction opposite to the first direction, the friction wheel 202 turns to the second rotation direction opposite to the first rotation direction because the friction pad 2022 is in contact with the second document, and the sleeve 2021 of the friction wheel 202 also rotates to the second rotation direction, and the second spring part 20232 is driven by the coil spring 2023 is fixed (tightly bound) on the axle 2024 due to the factor of rotation direction, and the first spring part 20231 in contact with the first inner wall part 20211 is also twisted in the second rotation direction along with the rotation of the first inner wall part 20211 , and the first spring part 20231 must overcome the internal stress generated by the interference between the first spring part 20231 and the first inner wall part 20211 to generate the second damping torque. Therefore, the friction wheel 202 provides a second frictional force close to zero to the second document S2, so that the second document can be taken out from the automatic document feeder without being affected by too much resistance when it is moved in the second direction. .

It should be noted that the sleeve 2021 in the second preferred embodiment has a first inner wall portion 20211 and a second inner wall portion 20212 , and the inner wall of the sleeve 2021 is an inclined inner wall. The first inner wall portion 20211 of the sleeve 2021 is gradually narrowed, so that the interference between the first spring portion 20231 in the sleeve 2021 and the first inner wall portion 20211 is relatively uniform, so that the generation of damping torque is smooth and stable.

In addition, the present invention also provides a third preferred embodiment with better effects. Please refer to FIG. 8 and FIG. 9 at the same time. FIG. 8 is a three-dimensional exploded view of the friction wheel module of the present invention in the third preferred embodiment, and FIG. 9 is a cross-sectional view of the structure of the friction wheel module in the third preferred embodiment of the present invention. The friction wheel module 30 includes a friction wheel bracket 301 , a friction wheel 302 and an elastic element 303 . The friction wheel bracket 301 is used to place the friction wheel 302, and the elastic element 303 is arranged on the friction wheel bracket 301 and is in contact with the friction wheel 302 to provide an elastic positive force to the friction wheel 302, so that the friction wheel 302 is relative to the friction wheel bracket 301 moves up and down. In this preferred embodiment, the elastic element 303 is a supporting torsion spring.

Next, the structure of the friction wheel 302 will be described. The friction wheel 302 includes a first sleeve 3021 , a second sleeve 3022 , a friction pad 3023 , a coil spring 3024 , a one-way clutch 3025 and a wheel shaft 3026 . The first sleeve 3021 has a sleeve inner tube 30211, the second sleeve 3022 is disposed in the first sleeve 3021, and the second sleeve 3022 has a sleeve outer tube 30221, located at one end of the second sleeve 3022, Used to contact with one end of the sleeve inner tube 30211, the diameter d2' of the sleeve inner tube 30211 is smaller than the diameter d1' of the sleeve outer tube 30221, so that the interference between the first spring part 30241 and the sleeve outer tube 30221 The amount is greater than the interference amount between the second spring part 30242 and the inner tube 30211 of the sleeve.

The friction pad 3022 surrounds the first sleeve 3021 for contacting with the second document S2 to provide friction. In this preferred embodiment, the friction pad 3023 is a rubber tire. The coil spring 3024 is set in the first sleeve 3021, one end of the coil spring 3024 is sleeved on the sleeve outer tube 30221 to form a first spring part 30241, and the other end of the coil spring 3024 is sleeved on the sleeve inner tube 30211 And a second spring part 30242 is formed, and the first spring part 30241 has a first spring inner diameter r1', and the second spring part 30242 has a second spring inner diameter r2' smaller than the first spring inner diameter r1'. The one-way clutch 3025 is disposed in the second sleeve 3022 to prevent the second sleeve 3022 from rotating in the first rotation direction and only allow the second sleeve 3022 to rotate in the second rotation direction. The axle 3026 passes through the first sleeve 3021 , the second sleeve 3022 and the one-way clutch 3025 , and the axle 3026 also includes a limiting edge 30261 for fixing to the friction wheel bracket 301 so that the axle 3026 is fixed and cannot rotate.

Next, the working situation of the friction wheel module will be described. When the automatic document feeder intends to feed the first document (not shown in the figure) and the second document (not shown in the figure), the paper picking mechanism (not shown in the figure) The second rotation direction rotates to feed the first document and the second document so that the first and second documents move in a first direction (not shown in the figure), at this time, the first document and the second document abut against the friction wheel 302 , the friction wheel 302 is moved downward relative to the friction wheel support 301 , so that the first document and the second document enter the automatic document feeder. When the friction wheel 302 rotates in the first rotation direction due to the contact between the friction pad 3023 and the second document, the first sleeve 3021 also rotates in the first rotation direction, and the second sleeve 3022 is restricted by the one-way clutch 3025 and cannot rotate. The first spring part 30241 is fixed on the sleeve outer tube 30221, and the second spring part 30242 is twisted relative to the sleeve inner tube 30211 to generate a first damping torque. Therefore, the friction wheel 302 provides the first frictional force corresponding to the first damping torque to the second document, so that the second document cannot be fed while the first document is being fed to move in the first direction.

And when the first document is fed into the automatic document feeder and paper jam occurs, the first document must be taken out from the automatic document feeder, so the first document is moved in a second direction opposite to the first direction. When the first file moves to the second direction, the friction wheel 302 turns to the second rotation direction because the friction pad 3023 is in contact with the second file, and the first sleeve 3021 also rotates to the second rotation direction, and the first spring part 30241 It is fixed on the sleeve outer tube 30221, and the second spring part 30242 is fixed on the sleeve inner tube 30211, so that the second sleeve 3022 rotates with the rotation of the first sleeve 3021, and the one-way clutch 3025 Rotating relative to the axle 3026 generates a second damping torque; wherein the first damping torque is greater than the second damping torque. Since the one-way clutch 3025 can rotate smoothly relative to the axle 3026, the interference between the one-way clutch 3025 and the axle 3026 is almost zero, so the second damping torque approaches zero. The second frictional force corresponding to the second damping torque is also close to zero, so that the second document can be taken out smoothly without being affected by resistance when it is moved in the second direction. According to the above, the coil spring provided inside the friction wheel disclosed in the present invention has a first spring portion with a larger inner diameter and a second spring portion with a smaller inner diameter. Therefore, when the coil spring is twisted, according to the first spring portion and the second spring portion, Different magnitudes of the first damping torque and the second damping torque can be obtained due to different interferences generated by the spring portion, and the first damping torque is greater than the second damping torque. Through the above structure, the friction wheel can generate damping torques in two directions, and the two damping torques are different in size, so that when the automatic document feeder jams, it is not necessary to open the upper cover of the automatic document feeder, but directly Documents are removed from the automatic document feeder by moving in the eject direction.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the claims of the present invention. Therefore, all other equivalent changes or modifications that do not deviate from the spirit disclosed in the present invention should include Within the protection scope of the claims of the present invention.

Claims (22)

1. a friction wheel is applied to an automatic paper feeder, and so that the friction force that is used for separating one first file and one second file to be provided, wherein this second file is positioned at this first file top, and this friction wheel comprises:

One sleeve has a sleeve lining;

One friction pad is surrounded on this sleeve, in order to contact with this second file;

One coil spring, be arranged in this sleeve, this coil spring has one first spring portion and one second spring portion, and this first spring portion has one first spring inside diameter, this second spring portion has one second spring inside diameter less than this first spring inside diameter, and this first spring portion contacts with this sleeve lining; And

One wheel shaft passes this coil spring and contacts with this second spring portion; Wherein when this second file moves toward a first direction, this sleeve rotates toward one first hand of rotation, this first spring portion is reversed toward this first hand of rotation and is expanded this first spring inside diameter of this first spring portion, this first spring portion is fixed by this sleeve lining, and the second spring portion is reversed and is produced one first damping moment of torsion with respect to this wheel shaft; After this first spring inside diameter expansion of this first spring portion, and when this second file moves toward the second direction in contrast to this first direction, this sleeve rotates toward one second hand of rotation, this second spring portion is fixed on this wheel shaft, and this first spring portion is reversed and produces one second damping moment of torsion; Wherein this first damping moment of torsion is greater than this second damping moment of torsion.

2. friction wheel as claimed in claim 1, wherein one first inner wall part of this sleeve lining has one first sleeve diameter, and this first inner wall part approaches an end of this sleeve, and one second inner wall part of this sleeve lining has one second sleeve diameter, and this second inner wall part approaches an other end of this sleeve; Wherein this first sleeve diameter is less than this second sleeve diameter.

3. friction wheel as claimed in claim 2, wherein this sleeve lining is a tilt internal wall.

4. friction wheel as claimed in claim 2, wherein this first spring portion contacts with this first inner wall part, this second spring portion does not contact and contacts with this wheel shaft with this second inner wall part, when this sleeve rotates toward this first hand of rotation, this first spring portion is reversed toward this first hand of rotation and is expanded this first spring inside diameter of this first spring portion, this first spring portion is fixed by this first inner wall part, and the second spring portion is reversed and is produced this first damping moment of torsion with respect to this wheel shaft; After this first spring inside diameter expansion of this first spring portion, and when this second file moves toward this second direction, this sleeve rotates toward one second hand of rotation, and this second spring portion is fixed by this wheel shaft, and this first spring portion is reversed and produces this second damping moment of torsion.

5. friction wheel as claimed in claim 1, wherein this first spring portion off-centre is connected in this second spring portion.

6. friction wheel as claimed in claim 1 is characterized in that also comprising that one holds axle, stretches into this end of this sleeve, is used to hold when this wheel shaft stretches into this other end of this sleeve this wheel shaft.

7. a friction wheel is applied to an automatic paper feeder, and so that the friction force that is used for separating one first file and one second file to be provided, wherein this second file is positioned at this first file top, and this friction wheel comprises:

One first sleeve has pipe in the sleeve;

One second sleeve is arranged in this first sleeve, and this second sleeve has a sleeve outer tube, is positioned at an end of this second sleeve, in order to this sleeve in an end in contact of pipe;

One friction pad is surrounded on this first sleeve, in order to contact with this second file;

One coil spring, be arranged in this first sleeve, this helical spring end is sheathed on this sleeve outer tube and forms one first spring portion, this helical spring other end is sheathed on to manage in this sleeve and upward forms one second spring portion, and this first spring portion has one first spring inside diameter, and this second spring portion has one second spring inside diameter less than this first spring inside diameter;

One free-wheel clutch is arranged in this second sleeve, carries out the rotation of one first hand of rotation in order to stop this second sleeve; And

One wheel shaft passes this first sleeve, this second sleeve and this free-wheel clutch; Wherein when this second file moves toward a first direction, this first sleeve rotates toward this first hand of rotation, this second sleeve is limited by this free-wheel clutch and can't rotates, this first spring portion is fixed on this sleeve outer tube, and the second spring portion is reversed and is produced one first damping moment of torsion with respect to pipe in this sleeve; When this second file moves toward the second direction in contrast to this first direction, this first sleeve rotates toward one second hand of rotation, this first spring portion is fixed on this sleeve outer tube, and this second spring portion is fixed on the interior pipe of this sleeve, and this second sleeve is rotated along with the rotation of this first sleeve, and this free-wheel clutch produces this second damping moment of torsion with respect to this wheel shaft rotation; Wherein this first damping moment of torsion is greater than this second damping moment of torsion.

8. friction wheel as claimed in claim 7, wherein the caliber of pipe makes the magnitude of interference between this first spring portion and this sleeve outer tube greater than the magnitude of interference between pipe in this second spring portion and this sleeve less than the caliber of this sleeve outer tube in this sleeve.

9. a friction wheel module of using friction wheel is applied to an automatic paper feeder, and so that the friction force that is used for separating one first file and one second file to be provided, wherein this second file is positioned at this first file top, and this friction wheel module comprises:

One friction wheel support;

One friction wheel is set on this friction wheel support, and this friction wheel comprises:

One sleeve has a sleeve lining;

One friction pad is surrounded on this sleeve, in order to contact with this second file;

One coil spring, be arranged in this sleeve, this coil spring has one first spring portion and one second spring portion, and this first spring portion has one first spring inside diameter, this second spring portion has one second spring inside diameter less than this first spring inside diameter, and this first spring portion contacts with this sleeve lining; And

One wheel shaft passes this coil spring and contacts with this second spring portion; Wherein when this second file moves toward a first direction, this sleeve rotates toward one first hand of rotation, this first spring portion is reversed toward this first hand of rotation and is expanded this first spring inside diameter of this first spring portion, this first spring portion is fixed by this sleeve lining, and the second spring portion is reversed and is produced one first damping moment of torsion with respect to this wheel shaft; After this first spring inside diameter expansion of this first spring portion, and when this second file moves toward the second direction in contrast to this first direction, this sleeve rotates toward one second hand of rotation, this second spring portion is fixed on this wheel shaft, and this first spring portion is reversed and produces one second damping moment of torsion; Wherein this first damping moment of torsion is greater than this second damping moment of torsion; And

One elastic element is arranged on this friction wheel support, and contacts with this friction wheel, to this friction wheel this friction wheel is moved up and down in order to an elastic force to be provided with respect to this friction wheel support.

10. friction wheel module as claimed in claim 9, wherein one first inner wall part of this sleeve lining has one first sleeve diameter, and this first inner wall part approaches an end of this sleeve, and one second inner wall part of this sleeve lining has one second sleeve diameter, and this second inner wall part approaches an other end of this sleeve; Wherein this first sleeve diameter is less than this second sleeve diameter.

11. friction wheel module as claimed in claim 10, wherein this sleeve lining is a tilt internal wall.

12. friction wheel module as claimed in claim 10, wherein this first spring portion contacts with this first inner wall part, this second spring portion does not contact and contacts with this wheel shaft with this second inner wall part, when this sleeve rotates toward this first hand of rotation, this first spring portion is reversed toward this first hand of rotation and is expanded this first spring inside diameter of this first spring portion, this first spring portion is fixed by this first inner wall part, and the second spring portion is reversed and is produced this first damping moment of torsion with respect to this wheel shaft; After this first spring inside diameter expansion of this first spring portion, and when this second file moves toward this second direction, this sleeve rotates toward one second hand of rotation, and this second spring portion is fixed by this wheel shaft, and this first spring portion is reversed and produces this second damping moment of torsion.

13. friction wheel module as claimed in claim 9, wherein this first spring portion off-centre is connected in this second spring portion.

14. friction wheel module as claimed in claim 9 is characterized in that also comprising that one holds axle, stretches into this end of this sleeve, is used to hold when this wheel shaft stretches into this other end of this sleeve this wheel shaft.

15. friction wheel module as claimed in claim 9, wherein this elastic element also comprises a torsion spring arm, in order to contact with this friction wheel and to provide this elastic force to this wheel shaft, this friction wheel is moved up and down with respect to this friction wheel support.

16. friction wheel module as claimed in claim 15, wherein this elastic element is a support torsion spring.

17. friction wheel module as claimed in claim 9, wherein this wheel shaft also comprises a restriction edge, in order to be fixed in this friction wheel support, this wheel shaft is fixed and can't rotates.

18. a friction wheel module of using friction wheel is applied to an automatic paper feeder, so that the friction force that is used for separating one first file and one second file to be provided, wherein this second file is positioned at this first file top, and this friction wheel module comprises:

One friction wheel support;

One friction wheel is set on this friction wheel support, and this friction wheel comprises:

One first sleeve has pipe in the sleeve;

One second sleeve is arranged in this first sleeve, and this second sleeve has a sleeve outer tube, is positioned at an end of this second sleeve, in order to this sleeve in an end in contact of pipe;

One friction pad is surrounded on this first sleeve, in order to contact with this second file;

One coil spring, be arranged in this first sleeve, this helical spring end is sheathed on this sleeve outer tube and forms one first spring portion, this helical spring other end is sheathed on to manage in this sleeve and upward forms one second spring portion, and this first spring portion has one first spring inside diameter, and this second spring portion has one second spring inside diameter less than this first spring inside diameter;

One free-wheel clutch is arranged in this second sleeve, carries out the rotation of one first hand of rotation in order to stop this second sleeve; And

One wheel shaft passes this first sleeve, this second sleeve and this free-wheel clutch; Wherein when this second file moves toward a first direction, this first sleeve rotates toward this first hand of rotation, this second sleeve is limited by this free-wheel clutch and can't rotates, this first spring portion is fixed on this sleeve outer tube, and the second spring portion is reversed and is produced one first damping moment of torsion with respect to pipe in this sleeve; When this second file moves toward the second direction in contrast to this first direction, this first sleeve rotates toward one second hand of rotation, this first spring portion is fixed on this sleeve outer tube, and this second spring portion is fixed on the interior pipe of this sleeve, and this second sleeve is rotated along with the rotation of this first sleeve, and this free-wheel clutch produces this second damping moment of torsion with respect to this wheel shaft rotation; Wherein this first damping moment of torsion is greater than this second damping moment of torsion; And

One elastic element is arranged on this friction wheel support, and contacts with this friction wheel, to this friction wheel this friction wheel is moved up and down in order to an elastic force to be provided with respect to this friction wheel support.

19. friction wheel module as claimed in claim 18, wherein the caliber of pipe makes the magnitude of interference between this first spring portion and this sleeve outer tube greater than the magnitude of interference between pipe in this second spring portion and this sleeve less than the caliber of this sleeve outer tube in this sleeve.

20. friction wheel module as claimed in claim 18, wherein this wheel shaft also comprises a restriction edge, in order to be fixed in this friction wheel support, this wheel shaft is fixed and can't rotates.

21. friction wheel module as claimed in claim 18, wherein this elastic element also comprises a torsion spring arm, in order to contact with this friction wheel and to provide this elastic force to this wheel shaft, this friction wheel is moved up and down with respect to this friction wheel support.

22. friction wheel module as claimed in claim 21, wherein this elastic element is a support torsion spring.

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