JPH09240094A - Rolled sheet tube holding device for image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolled sheet tube holding device which can be easily attached to or detached from a rolled sheet tube and can be effectively fixed to the tube. SOLUTION: Eight grooves 101c for containing the arms 102b of a locking part 102 are formed on the end of a cylindrical part 101e extended from the flange 101a of a holder body 101. The shaft 104a extended from the base 104f of a knob 104 is inserted into the hole 101d of the body 101, the boss 104d of the end is inserted into the hole 102d of the part 102, and a washer 105 is clamped by a screw 106. A mechanism (pin 1043, cam surface 101f, protrusion 104c and cam surface) for axially moving the knob 104 when the knob 104 is rotated is provided at the knob 104 and body 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper roll rolled out from a roll paper tube, and an image forming apparatus such as a large-sized plotter that forms an image on the paper rolls out the paper smoothly. The present invention relates to a roll paper tube holding device for holding a roll paper tube.

[0002]

2. Description of the Related Art Paper is unwound from a roll paper tube formed by winding the paper in a roll shape, the paper is conveyed to a recording unit to form an image, and after the image is formed, the paper is cut into a predetermined length and discharged. In such an image forming apparatus, various methods have been conventionally proposed as a method of rotatably holding the roll paper tube in the image forming apparatus.

In an inexpensive image forming apparatus such as a data printing device of a facsimile or a measuring instrument which does not require high printing accuracy, the peripheral surface of the roll paper tube is held and the paper is only fed out and wound around the roll paper tube. It will never be returned.

In an image forming apparatus such as a large format plotter or a copying machine which requires highly accurate sheet feeding and rewinding operations, both ends of a roll paper tube are held by a holding device such as a paper tube holder. Is positioned to ensure the conveyance accuracy, and the holding device is rotationally driven to rewind the paper to the roll paper tube. If necessary, the holding device is rotated in the direction opposite to the paper transport direction to apply back tension to the paper being recorded.

In the latter method of mounting the holding device on both ends of the roll paper tube, it is necessary to ensure the positional accuracy of the holding device in the axial direction with respect to the roll paper tube in order to ensure the paper conveyance accuracy. Also, the holding device must not rotate with respect to the roll paper tube in order to transfer rotational drive to the roll paper tube through the holding device. Further, the holding device needs to be easily attached to and detached from the roll paper tube when the roll paper tube is replaced.

As a conventional example, a penetrating roll paper tube holding device is shown in FIG. The roll paper tube holding device 200 is inserted into both ends of the roll paper tube, transmits a rotational drive, and determines a position of the roll paper tube in the axial direction.
It has a shaft 202 that penetrates through the roll paper tube and fixes the paper tube holders 201 on both sides of the roll paper tube to each other, and a screw type knob 203 that fixes the shaft 202 to the paper tube holder 201. The holding device 200 is attached to the roll paper tube as follows. A paper tube holder 201 having a shaft 202 fixed in advance to one end of the roll paper tube.
After that, the paper tube holder 201 is inserted into the other end portion of the roll paper tube, and the knob 203 is rotated and fixed to the shaft 202 passed previously.

As another conventional example, a fixed end type roll paper tube holding device is shown in FIG. The roll paper tube 30 has a core 30a.
And a sheet of paper 30b wound in a roll on it. The roll paper tube holding device 300 presses the inner surface of the core 30a and the paper tube holder 301 that determines the axial position of the roll paper tube 30 while transmitting the rotation drive, and rolls the paper tube holder 301 by the frictional force. It has a stopper 303 fixed to the paper tube 30, a spring 302 for urging the stopper 303 toward the inner surface of the winding core 30a, and a lid 304 for guiding the spring 302. This holding device 300
Is inserted and attached to each end of the roll paper tube 300.

[0008]

In the former conventional example, the holding device 200 is securely fixed to the roll paper tube, but the number of parts is increased by the amount of the shaft 202 that is passed through the roll paper tube. Further, when the roll paper tube is long, the shaft 202 becomes long accordingly, so that it becomes very difficult to insert the shaft into the roll paper tube, and it becomes troublesome to mount the holding device 200.

In the latter conventional case, in order to securely fix the holding device 300 to the roll paper tube 30, the elastic force of the spring 302 must be strong. However, if the elastic force of the spring 302 is strong, it becomes difficult to mount the holding device 300 on the roll paper tube 30. That is, if the easy mounting is to be realized, the certainty of fixing is sacrificed, and if the reliable fixing is to be realized, the ease of mounting is sacrificed.

The present invention has been made in order to improve such an actual situation, and an object thereof is to make it possible to easily attach and detach to and from a roll paper tube and to surely fix it to the roll paper tube. A tube holding device is provided.

[0011]

[Means for Solving the Problems]

[Structure] The present invention is a roll paper tube holding device for rotatably holding a roll paper tube in an image forming apparatus for feeding an image from a roll paper tube formed by winding a paper roll to record an image. A cylindrical insertion part to be inserted into the core of the paper tube and a disk-shaped flange part provided at one end of the insertion part, the diameter of which is larger than the diameter of the roll paper tube. The flange part that abuts the end side surface of the roll paper tube when it is inserted into the core of the roll paper tube, and the insertion part of the insertion part that projects from the outer peripheral surface of the insertion part along the radial direction inclined to the flange part side It has a plurality of claws provided inside, an operating part for projecting and retracting motion of the claw, and a transmitting part for transmitting the movement of the operating part to the claw to cause the projecting and retracting motion to the claw. ing.

[Operation] When the roll paper tube holding device is mounted on the roll paper tube, the insertion portion is inserted into the core of the roll paper tube until the flange contacts the side surface of the end of the roll paper tube. At this time, the claw portion is previously retracted into the insertion portion. The operation unit is rotatably provided, for example, on the roll paper tube holding device, and by rotating the operation unit, the claw portion projects from the outer peripheral surface of the insertion unit. Since the claw portion obliquely projects from the outer peripheral surface of the insertion portion toward the flange portion and bites into the core of the roll paper tube, the roll paper tube holding device is fixed so as to be drawn into the roll paper tube.

When removing the roll paper tube holding device from the roll paper tube, the operating portion is rotated in the opposite direction to that when the operation portion is mounted. As a result, the claw portion is retracted into the insertion portion, so that the engagement between the roll paper tube holding device and the roll paper tube is eliminated, and the roll paper tube holding device can be easily pulled out from the roll paper tube.

[Effect] By rotating the operating portion, the claw portion obliquely protrudes from the insertion portion and bites into the core of the roll paper tube, so that the roll paper tube holding device is placed at an appropriate position with respect to the roll paper tube. Securely fixed.

By rotating the operating portion in the opposite direction, the claw portion retracts into the insertion portion, so that the roll paper tube holding device can be pulled out from the roll paper tube. Therefore,
Provided is a roll paper tube holding device that can be easily attached to and detached from a roll paper tube and can be surely installed at an appropriate position when it is installed.

[Configuration] In the above configuration, preferably
The transmission part is made of an elastic material. [Operation] Since the transmission member is formed of the elastic material, when the claw portion bites into the core of the roll paper tube, the extra force transmitted to the claw portion is absorbed by the elastic deformation of the transmission member. Therefore, even when the core of the roll paper tube is hard and the claw portion is difficult to bite, the operating portion can be rotated without applying a force extremely larger than usual, in other words, an excessive force.

[Effect] The roll paper tube holding device can be fixed to the roll paper tube with reasonable force.

[Structure] In the above structure, preferably, the transmission portion and the claw portion are integrally formed. [Operation] Since the transmission portion and the claw portion are integrally formed, the number of parts is reduced. [Effect] Since the number of parts is reduced, the cost is reduced.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. An image forming apparatus to which the roll paper tube holder of the present invention is applied is shown in FIG. This image forming apparatus has two systems of paper supply units and can accommodate two roll paper tubes 30 at the same time. The roll paper tubes 30 have roll paper tube holders, that is, paper tube holders 10 at both ends thereof.
The device is loaded with 0 attached.

Paper feed rollers 1, 4 and paper tube support collar 3,
9 cooperates with each other to support the paper tube holder 100, and the paper feed rollers 1 and 4 cooperate with the paper feed pinch rollers 2 and 5 that press the paper feed roller 1, 4 to feed the paper 50 fed from the roll paper tube 30. When the paper 50 is rewound, the paper tube support collars 3 and 9 rotate and drive the paper tube holder 100 in the opposite direction to the paper feeding. The paper feed sensors 6 and 7 detect the position of the leading edge of the paper 50 fed by the paper feed rollers 1 and 4. The roll guide 8 guides and conveys the paper 50. The drive roller 10 cooperates with the drive pinch roller 12 that presses the drive roller 10 to sandwich and convey the sheet 50. The drive motor 11 rotatably drives the drive roller 10 via the worm wheel and accurately controls the transport distance of the paper 50.

The carriage 16 is provided with a paper edge sensor 13, ink tanks 15 and 17, ink hoses 18 and 19, and a print head 27.
Guide scanning is performed in a direction orthogonal to the transport direction of 0. The paper edge sensor 13 detects the position of the leading edge of the paper 50. The print head 27 passes through the ink hoses 18 and 19 and the ink tank 1
The ink supplied from Nos. 5 and 17 is selectively ejected onto the paper 50 to form an image on the paper 50. The suction fan 25 sucks the sheet 50 to the platen 26 by suction, and stabilizes the posture of the sheet 50 during image printing.

The cutter 21 is a sheet 50 on which an image is formed.
Disconnect. The paper discharge roller 23, which is driven to rotate by the paper discharge motor 24, has the star wheel 22 that presses the discharge roller 23.
In cooperation with, the paper 50 on which the image is formed is conveyed without disturbing the image surface, and the attitude of the paper 50 is fixed when cutting,
Then, the cut sheet 50 is discharged.

Next, the printing operation will be described. Hereinafter, the paper 50 will be described as being fed from the roll paper tube 30 supported by the paper feed roller 1 and the paper tube support roller 3.

The paper core holder 100 is inserted and fixed at both ends of the roll paper core 30, and is placed on the paper feed roller 1 and the paper core support collar 3. The paper 50 fed from the roll paper tube 30 is sandwiched by the paper feed roller 1 and the paper feed pinch roller 2, and the apparatus stands by in this state until a print command arrives. When an image signal is input from an information processing device such as a personal computer or CAD and a print command is received, the paper 50 is conveyed by the paper feed roller 1 and is supplied to the nip portion of the drive roller 10 through the roll guide 8. At that time, when the paper feed sensor 6 detects the leading edge of the paper 50, the drive motor 11 starts the rotational drive of the drive roller 10. Thereafter, the paper 50 is conveyed by being sandwiched between the drive roller 10 and the drive pinch roller 12, and the paper edge sensor 13 causes the paper 50 to move.
When the arrival of the leading end of the sheet feeding roller 1 is detected, the sheet feeding roller 1 is released from the drive transmission mechanism (not shown) by the clutch (not shown), and then freely rotated. After the leading edge of the paper 50 is detected by the paper feed sensor 13, the paper 50 is conveyed while the conveyance distance is accurately controlled by the drive roller 10 and is conveyed by a predetermined amount while being sucked by the platen 26 by the suction fan 25. When the leading edge of the paper 50 reaches a predetermined position, the paper 50 is temporarily stopped at that position, and the carriage 1
6 is driven by a driving device (not shown) to scan at a constant speed in the direction perpendicular to the paper transport direction, and the print head 27
Selectively ejects ink to form a band-shaped image on the paper 50.

The paper 50 on which the image is formed is the cutter 2
1 to the discharge roller 23, and the discharge roller 2
3 and the star wheel 22 are sandwiched and sent out. After that, the paper 50 is temporarily stopped after being fed for a predetermined length,
After being cut by the cutter 21, the discharge roller 23
The part on which the image is formed is discharged to the outside of the apparatus. After that, the paper 50 is rewound on the roll paper tube 30,
The rewinding operation is ended when the leading edge of the paper 50 slightly passes the paper feed sensor 6, and the apparatus waits in this state until the next print command arrives.

In this image forming apparatus, the paper tube holder 100 is inserted and fixed at both ends of the roll paper tube 30 to keep the posture of the roll paper tube 30 constant and to rewind the paper 50 to the roll paper tube 30. Rotates the roll paper tube 30 by rotating the paper tube support collar 6.

Here, the structure of the paper tube holder 100 will be described. As shown in FIG. 2, the paper tube holder 100
Is a holder body 101, a locking portion 102, a lid portion 10.
3 has a knob 104.

In the holder body 101, a cylindrical portion 101e projects from a disc-shaped flange portion 101a, and the flange portion 101a has an abutting portion 101b at a connecting portion with the cylindrical portion 101e. On the peripheral edge of the end of the cylindrical portion 101e, oblique grooves 101c are formed at eight locations at equal intervals. The locking portion 102 has eight arm portions 102b radially extending obliquely from a circular base portion 102c, and a serrated claw portion 102a is formed at the tip of the arm portion 102b.
The movement of 2c is transmitted to the claw portion 102a via the arm portion 102b. The locking portion 102 is integrally formed by a thin plate-shaped spring member.

The lid portion 103 has a cylindrical shape with the same diameter as the cylindrical portion 101e, and has fastening means such as screws (not shown).
Is fixed to the cylindrical portion 101e. Lid section 103
Has eight protrusions 103a that fit in the respective grooves 101c formed in the cylindrical portion 101e, and each protrusion 103a is a groove 1
01c has a slope facing in parallel with the bottom surface. Thereby, when the lid 103 is fixed to the cylindrical portion 101e, a gap is formed between the protrusion 103a and the groove 101c,
The arm portion 102b of the locking portion 102 is housed in this gap.

The knob 104 has a disk-shaped base portion 104f and a handle portion 104b for rotating operation formed on the base portion 104f. A shaft 104a extends from the base 104f.
4a is passed through a hole 101d formed in the holder body 101. The boss 104d at the tip of the shaft 104a is passed through the hole 102d formed in the locking portion 102, and the washer 1
05 is fixed by the screw 106. As a result, the locking portion 102 is rotatably attached to the shaft 104a of the knob 104.

When the knob 104 is inserted, the holder body 1
01 is rotatably attached, and the knob 104 and the holder body 101 are provided with a mechanism for axially moving the knob 104 when the knob 104 is rotated. That is, axis 1
04a is provided with a pin 104e protruding in the radial direction. Corresponding to this, the pin 1 is attached to the holder body 101.
A cam surface 101f for guiding 04e is formed.
Further, two protrusions 104c are formed on the peripheral portion of the base 104f on the side of the shaft 104a. Correspondingly, a cam surface 101g for receiving the protrusion 104c is formed on the holder body 101 as shown in FIG. Has been done. This allows
The knob 104 moves in the axial direction with the rotation.

The knob 104 is set to "LO" in FIG.
When it is turned in the "CK" direction, it moves in the "B" direction.
Along with this, the locking portion 102 moves in the direction of "b", and at this time, the arm portion 102b slides on the bottom surface of the groove 101c, so that the locking portion 102 opens the arm portion 102b, and as a result, the claws are opened. The portion 102a projects from the outer peripheral surfaces of the cylindrical portion 101e and the lid portion 103. On the contrary, the knob 104 has a structure shown in FIG.
When it is turned in the direction of "FREE" in, the movement in the direction of "A" is performed. Along with this, the locking portion 102 moves in the direction of "a", and at this time, the arm portion 102b slides on the slope of the protrusion 103a, so that the locking portion 102 moves.
b is closed, and as a result, the claw portion 102a is retracted from the outer peripheral surfaces of the cylindrical portion 101e and the lid portion 103.

The paper tube holder 100 is attached to the roll paper tube 30 as follows. In the paper tube holder 100, the knob 104 is previously turned to the “FREE” side in FIG. 4D, and as shown in FIG. 4A, the insertion part including the cylindrical portion 101e and the lid portion 103 is rolled into a roll paper tube. It is inserted inside the winding core 30a of 30. The outer diameter of the insertion portion is slightly smaller than the inner diameter of the winding core 30a, and the insertion portion can be easily inserted into the winding core 30a.

As shown in FIG. 4B, the flange portion 10
When the contact portion 101b of 1a hits the core 30a, the insertion of the paper tube holder 100 is stopped, and the knob 104 is turned to the "LOCK" side in FIG. 4D.

When the knob 104 is turned in the "FREE" direction, as shown in FIG.
a is located inside the insertion part. Knob 104 is “LO
When turned to the "CK" side, the claw portion 102a moves outward as shown in FIG. 5 (B), and the claw portion 102a bites into the winding core 30a as shown in FIG. 5 (C). . As a result, the paper tube holder 100, as shown in FIG.
It is fixed to the roll paper tube 30.

At this time, the arm portion 102b of the locking portion 102
Is made of a thin plate-shaped spring member, so that the core 30a
It elastically deforms according to the hardness and inner diameter of the inner surface of the nail, absorbs an excessive amount of protrusion, and always has a constant force.
02a bites into the inner surface of the core 30a. For this reason, reliable fixing can be obtained with an appropriate operating force for turning the knob 104, and the fixing force does not decrease with time.

During the transition from the state shown in FIG. 5B to the state shown in FIG. 5C, a force is exerted on the paper tube holder 100 in the direction of drawing it into the roll paper tube 30. Therefore, the paper tube holder 10
If the insertion of 0 is incomplete, the paper tube holder 10
0 is drawn into the roll paper tube 30, and the contact portion 101b reliably contacts the core 30a. In this way, the incomplete insertion is automatically corrected at the same time when the knob 104 is rotated.

The roll paper tube 30 having the paper tube holders 100 mounted on both sides is placed on the paper feed roller 1 and the paper tube support collar 3, for example. At this time, the flange portion 101a
Fits into a positioning notch provided in the paper feed roller 1, and the widthwise position of the roll paper tube 30 is determined.

When removing the paper tube holder 100, the knob 1
Turn 04 to the “FREE” side in FIG. As a result, the claw portion 102a is housed inside the insertion portion, so that the paper tube holder 100 can be easily removed from the roll paper tube 30.

[0040]

According to the roll paper tube holding device of the present invention, the claw portion obliquely protrudes from the insertion portion by the operation of the operation portion and bites into the core of the roll paper tube to ensure the proper position with respect to the roll paper tube. It is fixed, and the claw portion is retracted into the insertion portion by the reverse operation of the operation portion and can be pulled out from the roll paper tube. Therefore, it is possible to obtain a roll paper tube holding device that can be easily attached to and detached from the roll paper tube, and that can be surely installed at an appropriate position during installation.

[Brief description of drawings]

FIG. 1 is a diagram showing an image forming apparatus to which a roll paper tube holding device of the present invention is applied.

FIG. 2 is an exploded perspective view of a paper tube holder that is an embodiment of the roll paper tube holding device of the present invention.

FIG. 3 is a partial cross-sectional perspective view of the knob and the holder body of FIG. 3 viewed from the opposite side.

FIG. 4 is a diagram showing a procedure for mounting the paper tube holder of FIG. 2 on a roll paper tube.

FIG. 5 is a diagram showing how the claw portion of the paper tube holder bites into the core of the roll paper tube.

FIG. 6 is a view showing a conventional penetrating roll paper tube holding device.

FIG. 7 is a diagram showing another conventional fixed end type roll paper tube holding device.

[Explanation of symbols]

 101 Holder Body 101a Flange 101e Cylindrical 101f Cam Surface 101g Cam Surface 102 Locking 102a Claw 102b Arm 103 Lid 104 Knob 104c Protrusion 104e Pin

Claims (3)

[Claims] 1. A roll paper tube holding device for rotatably holding a roll paper tube in an image forming apparatus for recording an image by feeding a paper from a roll paper tube formed by winding a paper roll. The cylindrical insertion part to be inserted into the core of the and the disk-shaped flange part provided at one end of the insertion part, the diameter of which is larger than the diameter of the roll paper tube The flange part that abuts the end side surface of the roll paper tube when it is inserted into the core of the tube, and it projects from the outer peripheral surface of the insert part along the radial direction inclined toward the flange part and is retractable inside the insert part. It has a plurality of claws provided, an operation part for projecting and retracting the claw, and a transmitting part for transmitting the movement of the operating part to the claw to cause the claw to project and retract. , A roll paper tube holding device for an image forming apparatus. 2. A roll paper tube holding device for an image forming apparatus according to claim 1, wherein the transmission portion is formed of an elastic material. 3. A roll paper tube holding device for an image forming apparatus according to claim 1, wherein the transmission portion and the claw portion are integrally formed.