JPH062984Y2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is an automatic document feeder which is mounted on, for example, an electrophotographic copying machine and sequentially supplies documents to be copied onto a document mounting table of the copying machine. Alternatively, the present invention relates to a sheet feeding device in an image forming apparatus.

(Prior Art) In an electrophotographic copying machine, an automatic document feeder, which sequentially supplies documents to be copied on a document mounting table on the upper side, is used by being mounted as necessary.

An example of a conventional paper feeder in the automatic document feeder is shown in FIGS. 4 and 5. The paper feeding device includes a paper feeding roller unit 92 and a reversing roller unit which are paired up and down at the leading end in the paper feeding direction of a document table 91 on which a document to be fed onto a document table of a copying machine is placed. 93 is provided. The paper feeding roller unit 92 has a paper feeding roller shaft 92a and a paper feeding roller 92b fitted onto the paper feeding roller shaft 92a. The reversing roller unit 93 includes a reversing roller shaft 9a.
3a and a reversing roller 93b fitted onto the reversing roller shaft 93a. The paper feed roller 92b is rotated in the clockwise direction indicated by an arrow A in FIG. 4 so as to contact the document fed from the document table 91 and feed the document in the downstream direction. Further, the reversing roller 93b, as shown by an arrow B in FIG.
It rotates in the same direction as the rotation direction of 2b, and prevents the conveyance of documents that are double-fed below the documents to be fed.

A pair of support arms 94 and the base end portions of the pair of support arms 94 are rotatably fitted onto the roller shaft 92a of the paper feed roller 92. The tip of each support arm 94 extends above the document table 91, and the feed roller portion 95 is supported by each tip. Each of the support arms 94 is structured such that a tip end portion thereof is synchronously rotated in the vertical direction by a cam mechanism 98.

The delivery roller portion 95 has a delivery roller shaft 95a rotatably installed between the tip ends of the respective support arms 94, and a pair of delivery rollers 95b externally fitted to each end portion of the delivery roller shaft 95a. Between the feed roller shaft 95a and the paper feed roller shaft 92a, a pair of belt transmission devices 96 using toothed belts 96a are provided outside the respective support arms 94. The rotation of 92a is transmitted to the feed roller shaft 95a via a driving pulley 96b fitted on the paper feed roller shaft 92a, a toothed belt 96a, and a driven pulley 96c fitted on the feed roller shaft 95a. .

The feeding roller unit 95 is rotated downward at a predetermined timing to form a pair of feeding rollers 95b with respect to the document on the document table 91.
Contact each other to feed the original document to the paper feed roller unit 92.

(Problems to be Solved by the Invention) The feed roller shaft 95a in the feed roller portion 95 is rotatably supported in each through hole 94a formed at the tip of each support arm 94. The feed roller shaft 95a is wound between a driven pulley 96c externally fitted to each end portion thereof and a driven pulley 96b externally fitted to the paper feed roller shaft 92a so as to face the driven pulleys 96c. The rotation of the paper feed roller shaft 92a is transmitted to the feed roller shaft 95a by the toothed belt 96a. Therefore, with each toothed belt 96a,
The respective end portions of the delivery roller shaft 95a are rotated in synchronization with each other, and the delivery rollers 95b fitted onto the respective end portions of the delivery roller shaft 95a are rotated in synchronization with each other. And
With the sending rollers 95b rotated in synchronization with each other, the sending rollers are set on the original on the original table 91 at a predetermined timing.
95b are brought into contact with each other, and the respective side portions of the original are synchronously sent out to the paper feeding roller section 92 side by the respective sending rollers 95b.

The driven pulley 96c externally fitted to the feed roller shaft 95a has a tooth groove formed on the outer peripheral surface thereof, and the tooth groove has a toothed belt 96a.
Meshes with. Since the feeding roller shaft 95a is merely rotatably installed between the pair of supporting arms 94, the tooth portion of the toothed belt 96a is caused by the vibration or the like generated by the operation of the document feeding device. Driven pulley 9
There is a possibility that so-called tooth skip may occur because the tooth groove of 6c does not mesh continuously. In the paired belt transmission device 96,
If one of the toothed belts 96a causes tooth jumping with respect to the driven pulley 96c, the ends of the feed roller shaft 95a cannot rotate in synchronization with each other, and the delivery rollers 95b rotate in synchronization with each other. Not done. As a result, the document is
When sending out to 92, the respective side portions of the document with which the sending rollers 95b abut are not conveyed in synchronization, and the document is fed in a state in which it is inclined from a predetermined posture with respect to the conveying direction.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to prevent toothed belts in each belt transmission from causing tooth jumping to a driven pulley mounted on a feed roller shaft. Therefore, it is an object of the present invention to provide a paper feeding device capable of reliably rotating the respective end portions of the feeding roller shaft in synchronization with each other.

(Means for Solving the Problems) In the paper feeding device of the present invention, the paper feeding roller is fitted onto the rotatably arranged paper feeding roller shaft, and the paper is fed in a predetermined direction by the paper feeding roller. A sheet feeding roller portion for feeding to the sheet feeding roller portion and a sheet feeding roller shaft of the sheet feeding roller portion are rotatably supported at their base ends, and the tip ends thereof extend in the direction opposite to the sheet feeding direction and an opening is formed at the tip. A plurality of support arms with parts are formed, and a delivery roller is externally fitted to a delivery roller shaft that is rotatably inserted in an opening of each support arm and is movable in the sheet feeding direction.
Between a feed roller portion that feeds the paper to the paper feed roller portion by the feed roller, a driving pulley connected to the paper feed roller shaft of the paper feed roller portion, and a driven pulley connected to the feed roller shaft. The toothed belt wound around the belt and the built-in end of each support arm, and the feed roller shaft is biased toward the end of each support arm in the opening to apply tension to the toothed belt. And a biasing means for performing the above-mentioned purpose.

(Embodiment) An embodiment of the present invention will be described below.

The paper feeding device of the present invention is used, for example, in an automatic document feeding device mounted on the top of an electrophotographic copying machine.

As shown in FIGS. 1 and 2, the sheet feeding device has a document table 10 on which a document 11 to be fed is placed.
A sheet feeding roller portion 20 and a reversing roller portion 30 which are paired with each other in the vertical direction are arranged on the side of the sheet feeding direction. The paper feed roller unit
A pair of support arms 50 and 50 each having a tip extending above the document table 10 are rotatably supported on the table 20,
The delivery roller 40 is supported at the tip of each support arm 50.

The paper feed roller unit 20 is a paper feed roller shaft rotatably arranged.
21 and, for example, three paper feed rollers 22, 22, 22, which are fitted onto the paper feed roller shaft 21 at appropriate intervals.
The power of a motor (not shown) is transmitted to the paper feed roller shaft 21, and the power of the motor causes the paper feed roller shaft 21 to feed an original onto the original placing table of the copying machine. It is rotated clockwise as indicated by arrow A. Each paper feed roller 22 has a first
As shown in the figure, a part of the outer peripheral surface is cut out in an arc shape, and each paper feed roller 22 is attached to a predetermined position of the paper feed roller shaft 21 so that the cut out parts are aligned with each other.

The reversing roller unit 30 is disposed below the paper feeding roller shaft 21 in parallel with the paper feeding roller shaft 21 and is rotatably arranged, and is fitted onto the reversing roller shaft 31. And two reversing rollers 32 and 32. The reversing roller shaft 31
Is a first direction which is in the same direction as the rotation direction of the paper feed roller shaft 21.
It is rotated in the direction indicated by arrow B in the figure. Each reversing roller 32
Are attached to the reversing roller shaft 31 so as to be positioned between the adjacent paper feed rollers 22.

Each paper feed roller 22 in the paper feed roller unit 20 is made of rubber, for example, and each reversal roller 32 in the reversal roller unit 30 is
The friction resistance is smaller than that of the paper feed roller 22, and is made of urethane rubber, for example. As a result, the original that abuts the paper feed roller 22 is fed onto the original placing table, and the original that is fed with the original abuts against the reversing roller 32 and is prevented from being conveyed.
Eventually, multiple documents are prevented from being fed in duplicate.

A pair of support arms 50 and 50 are supported on the paper feed roller shaft 21 of the paper feed roller unit 20. Each support arm 50
Is the three paper feed rollers 22 mounted on the paper feed roller shaft 21.
Are arranged on the outer side of each. Each support arm 50
Has its base end fitted onto the paper feed roller shaft 21 so that the paper feed roller shaft 21 can rotate, and its tip extends in the direction opposite to the document feed direction, and Located on 10.

A locking groove 51 having an opening 51a on the tip surface is provided at the tip of each support arm 50. Each locking groove 51
Is a feed roller shaft 41 in a feed roller portion 40 described later.
Has a size such that it can be fitted in the locking groove 51 with some margin, and the opening 51a of each locking groove 51 is shaped so that the feed roller shaft 41 can pass in the radial direction. The vertical distance is slightly smaller than the outer diameter of the feed roller shaft 41.

Each support arm 50 is formed with a spring accommodating portion 52 that communicates with the inner depth of each locking groove 51. In the spring accommodating portion 52,
A push spring 53 is fitted inside, and one end of the push spring 53 is locked to an abutting member 54 arranged in the locking groove 51. The pressing spring 53 presses the roller shaft 41, which will be described later, toward the tip of the support arm 50 via the contact member 54.

Each support arm 50 is provided with cam followers 55 and 55 extending upward from its base end.

As shown in FIG. 3, at the tip of each support arm 50, a feed roller portion 40 is provided so as to be attachable to and detachable from each support arm 50. The delivery roller portion 40 includes a delivery roller shaft 41 that is rotatably installed between the tip portions of the support arms 50, and a pair of delivery rollers 42 that are disposed on the delivery roller shaft 41 at appropriate intervals. 42 and.

The feed-out roller shaft 41 is fitted in the locking groove 51 provided at the tip of each support arm 50 with some margin,
Therefore, the feeding roller shaft 41 is movable and rotatable in the locking groove 51 in the paper feeding direction and the non-paper feeding direction. Each end of the feed roller shaft 41 is connected to each support arm 50.
It is in a state of extending further outward. Each support arm 50
The abutting member 54 disposed in the locking groove 51 is in contact with the feed roller shaft 41 fitted in the locking groove 51 by the pressing force of the pressing spring 53. Roller shaft 41 is each support arm
It is biased toward the tip of 50. The contact member 54 is made of a material having a low friction coefficient so that the contact member 54 does not hinder the rotation of the feed roller shaft 41 due to the contact.

The left and right side portions of the opening 51a in each locking groove 51 are open, and the distance between the upper and lower portions is equal to that of the feed roller shaft.
Although slightly smaller than the outer diameter of 41, the opening 51a
The upper and lower parts of the feed roller shaft 41 are spread out against their elastic force, and the feed roller shaft 41 is pulled in the radial direction of the feed roller shaft 41 toward the tip of each support arm 50. It passes through the opening 51a and is detached from the support arm 50.

The pair of feed rollers 42 and 42 fitted onto the feed roller shaft 41 are fitted onto a pair of collars 43 and 43 fixedly fitted onto the feed roller shaft 41 at predetermined positions.
Each feeding roller 42 is made of rubber, for example, and is attached to and detached from each collar 43 by its elastic force.

A pair of belt transmission devices 60 are interposed between the paper feed roller shaft 21 of the paper feed roller unit 20 and the delivery roller shaft 41 of the delivery roller unit 40. Each belt transmission 60
Are driven pulleys 61 having externally fitted and fixed outer end portions of the feeding roller shaft 41 extending outwardly of the respective support arms 50 and tooth grooves formed on the outer peripheral surface thereof, and driven pulleys of the paper feed roller shaft 21. A driving pulley 62 having an outer peripheral surface formed with a tooth groove and a toothed belt 63 wound around the driving pulley 62 and the driven pulley 61 facing each other. Have and. Therefore, each driving pulley 62 rotates in synchronization with the rotation of the paper feed roller shaft 21, and the rotation of each driving pulley 62 is transmitted to each driven pulley 61 via the toothed belt 63, and each driven pulley 61 is Each rotates in synchronization. As a result, the ends of the delivery roller shaft 41 are rotated in synchronization with each other, and the respective delivery rollers 42 are also rotated in synchronization with each other.

Above the paper feed roller unit 20, a cam mechanism 70 for intermittently rotating the tip of each support arm 50 in the vertical direction is arranged. The cam mechanism 70 includes a cam shaft 71 disposed above the paper feed roller shaft 21 in the paper feed roller unit 20 and parallel to the paper feed roller shaft 21, and each support arm 50 for the cam shaft 71. And cam bodies 72 and 72 respectively arranged at positions facing each other.

The cam shaft 71 is rotatable in the clockwise direction indicated by the arrow C in FIG. 1 and is configured to be intermittently rotated one rotation at a time. Each of the cam bodies 72 is fixed to a predetermined position of the cam shaft 71 so that the tip of the cam body 72 can come into contact with the upper end of the cam follower 55 extending upward from the base end of each support arm 50. Then, each cam body 72 of the cam shaft 71 is a supporting arm.
The rotation is stopped in the state of being in contact with the cam follower 55 in 50, and in such a state, the cam shaft 71
Is rotated once and then stopped again. When the tip end of each cam body 72 contacts the cam follower 55, each support arm 50
Rotates upward so as to separate the front end from the original on the original table 10. As a result, the feeding rollers 42 in the feeding roller section 40 mounted on the supporting arms 50 are
Separate from the upper document 11. Each cam body 72 has each support arm 50
Each support arm can be separated from the cam follower 55 in
The feed roller 50 rotates downward due to the weight of the feed roller unit 40, and each feed roller 42 contacts the document 11 on the document table 10.

The sheet feeding device having such a configuration operates as follows. When feeding the original 11 on the original table 10 to the original table of the copying machine, first, the paper feed roller shaft 21 of the paper feed roller unit 20 is rotated. The rotation of the paper feed roller shaft 21 is performed by a pair of belt transmission devices 60 using the toothed belts 63.
It is transmitted to the delivery roller shaft 41 in the delivery roller unit 40. In this case, the feed roller shaft 41 in the feed roller portion 40 is provided with a pressing spring 53 built in the tip portion of each support arm 50.
The driven pulley 61 mounted on the feed roller shaft 41 is urged in a direction away from the driving pulley 62 because the support arm 50 is pressed toward the tip end of the support arm 50, and the toothed belt 63 is tensioned. Granted. As a result, the toothed belt 63
Securely meshes with the tooth spaces formed on the outer peripheral surfaces of the driving pulley 62 and the driven pulley 61, and reliably transmits the rotation of the driving pulley 62 to the driven pulley 61 without causing tooth jumping.

In this manner, the cam shaft 71 of the cam mechanism 70 is rotated while the ends of the feed roller shaft 41 are rotated in synchronization with each other by the belt transmission device 60 using the toothed belt 63.
Each cam body 72 releases the contact with the cam follower 55 on each support arm 50. As a result, the tip end of each support arm 50 is rotated downward due to the weight of the feed roller portion 40, and the feed roller is rotating integrally with the feed roller shaft 41.
42 contacts the uppermost original on the original table 10 and feeds the original to the paper feed roller unit 20 side.

After that, when the cam shaft 71 makes one rotation, the rotation of the cam shaft 71 is stopped while the cam body 72 is in contact with the cam followers 55 of the respective support arms 50, and the feed roller 42 is rotated upward so that the original document is rotated. Kept separate from.

The document fed to the paper feed roller unit 20 side by the feed roller 42 is fed between the paper feed roller 22 and the reversing roller 32, and is fed downstream by the rotation of the paper feed roller 22. In this case, the cutout portion of the paper feeding roller 22 is initially opposed to the reversing roller 32 so that the fed document is surely inserted between the paper feeding roller 22 and the reversing roller 32. It is located on the lower side. Further, when a plurality of originals are fed to the paper feed roller unit 20 in duplicate, the uppermost original is conveyed to the downstream side by the paper feed roller 22, while the other originals are rotated by the reversing roller 32. , Transported to the downstream side is prevented.

In this way, the delivery roller 42 of the delivery roller unit 40 rolls on the original while the original is being conveyed, and the original is worn and cannot be reliably delivered. For this reason, it is necessary to replace the delivery roller 42 with one that is not worn. In this case, the feed roller shaft
Against the urging force of the presser 53, the 41 is once moved in the paper feeding direction to loosen the tension of the toothed belt 63 in each belt transmission device 60, and the toothed belt 63 is moved to each driven pulley.
It is removed from 61, and in this state, the feeding roller shaft 41 is pulled toward the radial direction of each support arm 50. As a result, the feed roller shaft 41 is attached to each support arm 50.
Through the opening 51a of the locking groove 51 in the
It is separated from 0.

The delivery roller 40 separated from each support arm 50 is delivered from the collar 43 fitted on the delivery roller shaft 41.
Is pushed out against the elastic force and is released, and is moved in the axial direction of the feed roller shaft 41. And the sending roller 42
Is driven over the driven pulley 61 attached to the end of the feed-out roller shaft 41 to be separated from the feed-out roller shaft 41. Next, a new delivery roller 42 that is not worn
This operation is carried out in the opposite direction, and it is fitted onto the collar 43 of the feed roller shaft 41. As a result, a new delivery roller 42
Are fixed to the collar 43 by elastic force.

(Effect of the Invention) In the paper feeding device of the present invention, since the feeding roller shaft is biased toward the tip of the support arm by the biasing means built in the tip of the support arm, The driven pulley mounted on the feed roller shaft is urged in a direction away from the driving pulley, and tension is applied to the toothed belt wound around both pulleys. As a result, the toothed belt moves circularly without causing tooth jumping with respect to the driven pulley, and the respective feeding rollers mounted on the feeding roller shaft ensure that the document is conveyed in a predetermined posture.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a paper feeding device of the present invention, FIG. 2 is a perspective view of the paper feeding device of the present invention, FIG. 3 is a plan view of the main part, and FIG. 4 is a conventional paper feeding device. FIG. 5 is a perspective view showing the cross section of the main part of the paper device. 10 ... Original platen, 20 ... Paper feed roller section, 21 ... Paper feed roller shaft, 22
... paper feed roller, 30 ... reversing roller portion, 40 ... delivery roller portion, 41 ... delivery roller shaft, 42 ... delivery roller, 43 ... collar, 50 ... support arm, 51 ... engaging groove, 51a ... opening portion, 53 ...
Push spring, 54 ... Abutting member, 60 ... Belt transmission device, 61 ... Followed pulley, 62 ... Driving pulley, 63 ... Toothed belt, 70 ... Cam mechanism.

Claims (1)

[Scope of utility model registration request] 1. A paper feed roller, wherein a paper feed roller is externally fitted to a rotatably arranged paper feed roller shaft, and a paper feed roller unit for feeding paper in a predetermined direction by the paper feed roller, and the paper feed roller unit. A plurality of support arms, each having a base end rotatably supported by a paper feed roller shaft in the roller portion, a front end extending in a direction opposite to the paper feed direction, and an opening formed at the front end, A feed roller that is rotatably inserted in the opening of the support arm and movably in the paper feed direction is externally fitted to the shaft. The feed roller feeds the paper to the paper feed roller section. Section, a toothed belt wound between a driving pulley connected to the paper feeding roller shaft of the paper feeding roller unit and a driven pulley connected to the feed roller shaft, and a tip end portion of each support arm. Built-in, feed roller axis,
A sheet feeding device, comprising: a biasing unit that biases each support arm in the direction of the tip of each support arm to apply tension to the toothed belt.