JPH075201B2 - Pressure switching mechanism with paper feed roller pair - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed roller pair used for feeding a paper medium to an information input / output device. Attaching pressure (medium clamping force)
The present invention relates to a roller pressure switching mechanism in a pair of paper feed rollers for changing the pressure.

<< Prior Art >> Single-sheet media and continuous form media are used as paper media for information input / output devices. Feeding of single-cut media is performed by friction drive by sandwiching the paper medium between the receiving roller and the pressing roller of the paper feed roller pair, and feeding the continuous form medium is performed by using the marginal punch hole of the medium and the pin of the tractor or wheel. Is engaged and driven by a pin. Therefore, an information input / output device that uses a single-cut medium and a continuous form medium as a medium is provided with two types of paper feeding devices: a paper feeding roller pair and a pin driving device. When feeding the medium with the pin drive device, either reduce the pressure applied to the paper feed roller pair or release the pressure to separate the rollers from each other so that excess drive force or load is not applied to the medium. To do. In this case, when feeding the continuous form medium by pulling drive, the rollers are separated from each other, and when pushing continuous drive, the medium is lightly sandwiched by a pair of paper feed rollers to prevent loosening of the medium. Is normal.

The applicant of the present invention makes it possible to drive the paper feed roller pair and the pin drive device in both the forward and reverse directions, and to switch the paper feed roller pair to three stages of strong pressing force, weak pressing force and pressing force release. A printer having a structure capable of feeding a bill medium, pushing a continuous form medium, and pulling a continuous form medium has been proposed (JP-A-62-135384, JP-A-1).
-291966). In the printer, the cam drive is used to switch the pressure applied to the paper feed roller pair and the movable guide that switches the medium path between the single-cut medium and the continuous form medium. That is, the press roller of the paper feed roller pair is pivotally supported on the tip of an arm pivotally supported by a support shaft, and a cam for pushing the arm and a cam for engaging and disengaging the pressing spring for biasing the arm cause The contact / separation of the receiving roller and the pressure of the pressing roller are converted.

<< Problems to be Solved by the Invention >> Although the paper feed roller pair has a length corresponding to the maximum width of the medium used, a spring for pressing the pressing roller is provided only at one end of the paper feed roller pair. In the case of the above, the pressing force of the pressing roller becomes non-uniform in the width direction of the paper due to the twist of the support shaft of the arm and the roller shaft. In order to avoid this, it is preferable to provide a plurality of pressure springs. However, when a plurality of pressing springs are provided, the cam for switching the pressing force needs to press these springs at the same time, and therefore a long cam shaft in the width direction of the paper must be provided.

On the other hand, the paper feed roller pair is preferably provided as close as possible to the platen and the print head in order to ensure the clarity of printing at the edge of the paper. It is required to make the pressure switching mechanism more compact. A conventional pressure switching mechanism for a pair of paper feed rollers using a cam has a problem that it cannot sufficiently meet the above demand for downsizing because an extra member called a cam must be provided, and the structure becomes complicated. There is a drawback that the number of manufacturing and assembling steps of the device is increased.

The present invention has been made for the purpose of solving the above problems, and it is necessary to switch the pressure applied to a pair of paper feed rollers and to switch the medium path when it is necessary to switch the pressure. It is an object to obtain a mechanism of a more compact and simple structure for performing.

<< Means for Solving the Problem >> According to the present invention, the pressing force of the paper feed roller pair 4 is converted and released by the pivotal movement of the support shaft 42 of the arm 43 supporting the pressing roller 44 of the paper feed roller pair. In addition, the movable guide 7 for switching the medium path is switched if necessary.

In the structure of the present invention, the arm 43 that supports the pressing roller 44.
The support roller 42 so as to be rotatable relative to the support shaft 42, and
The mooring end 51 of the secondary pressure spring 47 for increasing the pressure of 44 is provided so as to face the peripheral surface of the support shaft 42, and the support shaft 42 is rotated by the pressing roller in the pressure direction to move the secondary pressure spring. The pressure pin 52 that is linked to the mooring end 51 is planted, and further, the pressure release pin 54 that is linked to the arm 43 is planted on the support shaft 42 by rotating the support shaft 42 in the opposite pressure direction. In the intermediate rotation region of 42, which is intermediate between the pressing direction and the counter pressing direction, the mooring end 51 of the secondary pressing spring is attached to the pressing spring 52.
And the arm 43 and the pressure release pin 54 are both released.

In the information input / output device provided with the movable guide 7 for switching the medium passage between the continuous form paper and the cut sheet, a piece 74 contacting the movable guide is mounted on the support shaft 42 so as to be rotatable relative to the support shaft 42. By arranging a path switching pin 76, which is separated from the joint according to the rotating operation of the sheet, on the support shaft 42, the movable guide can be switched at the same time as the pressure applied to the paper feed roller 4 is changed. You can

In a device that feeds a continuous form medium and a single form medium along different paper passages, a movable guide is often provided at the branch point, but a fixed guide is used to form the continuous form medium passage and the single form medium passage. It is also possible to use a structure that forms a shaft. If such a structure is used, it is naturally unnecessary to operate the movable guide 7, and
The operation of the movable guide 7 by 42 is not an essential constituent feature of the present invention.

<< Operation >> According to the above configuration, when the support shaft 42 is rotated in the direction in which the arm 43 is moved upward, the pressure release pin 54 and the arm 43 work together to move the arm 43 upward and receive the pressing roller 44. The roller 41 is separated from the roller 41 to release the pressure applied to the paper feed roller pair 4. From this state, if the support shaft 42 is rotated in the direction of moving the arm 43 downward, the pressing roller 44 will lose its own weight or the primary pressing spring 46 when the link between the pressing release pin 54 and the arm 43 is released. The receiving roller 41 is pressed with a weak force. Further support from this state
When the arm 42 is rotated in the downward direction of the arm 43, the pressure pin 52 is linked to the mooring end 51 of the secondary pressure spring, and the secondary pressure spring 47 is bent, and the pressing roller 44 is pressed by the spring force. Receiving roller 41
Apply pressure to. In this state, the pressure applied to the paper feed roller pair 4 increases with the rotation of the support shaft 42. Therefore, by stopping the support shaft 42 at an appropriate position, it is necessary to feed the single-cut medium. The pressing force can be obtained.

As described above, since the switching of the pressing force is performed at the time of switching between the single-cut medium and the continuous form medium, the rotation of the support shaft 42 at that time is used to rotate the piece 74 by the passage switching pin 76. , Piece 74
Can be brought into contact with the movable guide 7 to switch the movable guide, and the medium passage can be converted. The switching of the movable guide is performed until the mooring end 51 of the secondary pressure spring is pushed to a desired pressure from the weak pressure area after the pressure release pin 54 and the arm 43 are disengaged from each other in the above description. The rotation of the support shaft 42 during the time is used.

Further, according to the above structure, the support shaft 42 that supports the pressing roller 44 so as to be able to move up and down is used as it is to switch and release the pressing force of the paper feed roller pair, and also switch the medium path. Therefore, a dedicated member for switching such as a cam is not required, and the pins 52, 54, and 76 are set up on a support shaft that has been conventionally used. Switching of the pressing force and the medium passage is realized.

In order to perform the switching operation of the applied pressure, a drive device for rotationally driving the support shaft 42 is required. This drive device may have the same structure as the cam drive device in the conventional structure. Does not become complicated.

<< Embodiment >> FIG. 7 schematically shows the overall configuration of a printer including the pressure-applying switching mechanism of the present invention. In the illustrated printer, a pair of paper feed rollers 3 arranged before and after the printing section a. Four
Along with the switching of the pressing force, the movable guides 6 and 7 are converted in association with the rotational movements of the second support shaft 42 and the first support shaft 32.

In the figure, 11 is a paper feed table, 12 is a pick roller, 13 is a friction separation pad, and 14 is a feed roller pair, and these members constitute an automatic paper feed device for single-cut media.
15 is a manual paper feed tray, 3 is a first paper feed roller pair, 16
Is a print head, 17 is a platen, 4 is a second paper feed roller pair, 18 is a paper discharge roller pair, and 19 is a tractor.

The first and second paper feed roller pairs 3 and 4 are rotatably supported by receiving rollers 31 and 41 that are supported by the frame of the apparatus and support shafts 32 and 42 that are supported by the frame of the apparatus. Arm 33,
It is composed of pressing rollers 34 and 44 pivotally supported at the tip of 43.

Reference numerals 21, 22, 23, and 24 denote fixed guide plates, and these guide plates serve as an automatic paper feed passage b for a single-cut medium, a paper feed passage c for a manual feed medium, a continuous form medium passage d, and a paper discharge passage for a single-cut medium. A common passage f common to e and all media is formed. 6
Is a first movable guide, which is located at a lower position (see FIG. 11) shown by an imaginary line in the drawing when feeding the single-cut medium and guides the leading end of the single-cut medium between the print head and the platen. Reference numeral 7 denotes a second movable guide, which takes a position shown by a solid line in the figure (see FIG. 9) when processing a single-cut medium, and is switched to a position shown by an imaginary line in the figure (see FIG. 8) when processing a continuous form medium. The medium is guided to the continuous form medium passage d or the single-cut medium discharge passage e.

FIG. 1 is a plan view showing the support structure of the pressing roller 44 of the second paper feed roller pair, FIG. 2 is an enlarged view of the portion A, and FIG. 3 is an enlarged view of the portion B. In the illustrated apparatus, the presser roller shaft 45 is pivotally supported by five arms 43a to 43e, and each arm is a support shaft.
It is individually swingable around 42, and the pressing roller shaft 45 is rotatably supported at its tip. 46 and 47 are spindles
A pressure spring wound around 42 and having a working end 48 extending on the upper surfaces of the arms 43c and 43d, 43e. The pressure spring 46 is a primary pressure spring having its mooring end 49 locked to the immovable member 50, and the mooring ends 51 of the other two pressure springs 47 are the support shafts as shown in FIG. It is a protrusion that extends parallel to 42, and the spindle 42
A pressure pin 52 is erected at a position where it engages with the mooring end 51. A pin 53 parallel to the support shaft 42 is planted in the arms 43a and 43b at both ends in the vicinity of the support shaft 42, and a pressure release pin 54 is planted in the support shaft 42 at a position to engage with the pin 53. It is standing.

4 to 6 are diagrams showing the relationship between the rotation of the support shaft 42 and the operation of the pressing roller 44. In the state shown in FIG. 4 in which the support shaft 42 is rotated clockwise, the pressing pin 52 abuts on the mooring end 51 of the secondary pressing spring 47 and pushes it in the clockwise direction. 47 urges the arms 43d and e downward and presses the pressing roller 44 against the receiving roller 41 with a strong force. In the state of FIGS. 5 (a) and 5 (b) in which the support shaft 42 is rotated slightly counterclockwise from the state of FIG. 4, the pressure pin 52 is separated from the mooring end 51 of the secondary pressure spring, Moreover, the pressure release pin 54 and the arm pin 53 are not yet in contact with each other. In this state, the spring force of the second pressure spring 47 is released, and the pressing roller 44 moves to the primary pressure spring.
The receiving roller 41 is pressed only by the spring force of 46. When the support shaft 42 is further rotated counterclockwise from the state shown in FIG. 5, the pressure release pin 54 contacts the pin 53 of the arm and pushes up the arms 43a and 43b. In this state, the pressing roller 44 is separated from the receiving roller 41, and the pressing force of the paper feed roller pair 4 is released.

The above description based on FIGS. 1 to 6 is for the second paper feed roller pair 4, but the first paper feed roller pair 3 has a structure in which FIGS. And the operation is the same as that of the second paper feed roller pair 4. Therefore, the support shaft of the first paper feed roller pair and the second paper feed roller pair
The 32 and 42 may be linked by a gear train or the like so as to rotate in the opposite directions at the same speed, and these may be driven by the same motor.

8 and 9 are views showing a mechanism for switching the second movable guide 7 by the second support shaft 42. The second movable guide 7 is rotatably supported by the bracket 72 on the shaft 72 of the paper discharge roller. On the other hand, the second support shaft 42 is rotatably mounted with a piece 74 provided with a pressing projection 73 on the right end of the lower surface, and an engaging projection 75 protruding toward the front side in the figure is provided on the upper end of this piece. . A passage switching pin 76 is erected on the support shaft 42 at a position where it engages with the engagement protrusion 75.

When the pressure pin 52 is in the state shown in FIG. 4, the switching pin 76 engages with the engaging projection 75 to rotate the piece 74 to the right as shown in FIG. The second movable guide 7 is pushed down to communicate the single-cut sheet discharge passage e with the common passage f. On the other hand, when the pressurizing pin 52 and the pressurizing releasing pin 54 are in the states shown in FIGS. 5 and 6, the switching pin 76 is in the state shown in FIG. The movable guide 7 is returned counterclockwise in the drawing to connect the common passage f to the continuous book passage d.

FIGS. 10 and 11 show a switching structure of the first movable guide 6, in which the switching operation is performed by the switching pin 61 set up on the first support shaft 32. Reference numeral 62 denotes a support pin that is erected on the arm 33, and a piece 63 and an up spring 64 are rotatably inserted in the support pin 62. The first movable guide 6 is fixed to a bracket 65 that is rotatably inserted through the first support shaft 32, and an operating bar 66 extends toward the bridge 63 at the upper end of the bracket 65. 67 is a down spring rotatably inserted in the first support shaft 32, one end of which is locked by the support pin 62 and the other end of which pushes down the movable guide 6. The up spring 64 has a stronger spring force than the down spring 67, and one end of the up spring 64 has an arm 33.
Is fixed to a fixing pin 68 provided on the other side, and the other end urges the piece 63 clockwise in the drawing. Then, the projection 69 of the piece 63 contacts the tip of the operating bar 66 and urges it upward.

In the state of FIG. 10 in which the switching pin 61 is not operating, the clockwise urging force of the bracket 65 by the up spring 64 is larger than the counterclockwise urging force provided by the down spring 67, and the first movable guide 6 moves upward. In position. When the first support shaft 32 rotates clockwise, the switching pin 61 comes into contact with the second projection 70 provided on the piece 63 to rotate the piece 63 counterclockwise around the support pin 62, and the projection 69 of the piece. Release the contact of the operating bar 66. Therefore, the bracket 65 is rotated leftward in the figure by the urging force of the down spring 67, and the movable guide 6 is moved downward to the state shown in FIG.

FIG. 12 shows a pair of paper feed rollers 3 by rotation of the support shafts 32, 42,
4 is a diagram showing that, in addition to the switching of the pressing force of 4 and the switching of the movable guides 6 and 7, the connection and disconnection of the driving force to the pin driving device 19 can be performed by the rotating operation of the second support shaft 42. . In the figure, 81 is a gear fixed to the shaft of the receiving roller 41 of the second paper feed roller pair, and this gear is connected to a paper feed device drive motor (not shown). The pin drive device 19 is driven from the gear 81 via gear trains 82, 83, 84. The gear 84 is a slide gear provided so as to be slidable in the axial direction with respect to the shaft 85. On the other hand, an arm 86 is provided on the support shaft 42, and an operating pin 87 in the direction perpendicular to the paper surface of the figure is planted at the tip of this arm. A seesaw lever 89 is urged counterclockwise by a spring (not shown) on a fulcrum pin 88 fixed to the frame, and one end of the seesaw lever faces a position facing the operation pin 87 of the arm, Further, a taper surface 90 for pushing the side surface of the slide gear 84 is provided at the other end.

The position shown by the solid line in the figure corresponds to the state shown in FIG. 5, in which the seesaw lever 89 is retracted from the slide gear 84 by the urging force of the spring, and the pin drive device
19 is driven synchronously with the paper feed roller pair 4 via gear trains 82, 83, 84. When the spindle 42 is rotated clockwise from this state to the state corresponding to FIG. 4, the arm 86 is moved upward, whereby the seesaw lever 89 is rotated counterclockwise and the tapered surface 90 is slid. The gear 84 is pushed axially to disengage the gears 84 and 83. Therefore, the rotation of the gear 81 is no longer transmitted to the pin drive device 19.
Keeps stopped. That is, the pin drive device 19 is kept in a stopped state when feeding a single-cut medium shown by an imaginary line in the figure, and when pushing and feeding the continuous form medium, the pin drive device 19 which stops the continuous form medium is It can be kept in the engaged state, and after the printing process of the single-cut medium is completed, the second support shaft 42 is rotated counterclockwise to the continuous book processing state, and the gear 81 is reversed to retract it. It is possible to automatically send the continuous form media to the printing unit.

<< Effects of the Invention >> As will be understood from the above description, by the mechanism of the present invention, the pressurizing force of the paper feed roller pair of a printer or other information input / output device for processing continuous form media and single-cut media and It is possible to switch the medium path and drive of the pin drive device by rotating the support shaft supporting the pressing roller of the paper feed roller pair, and its structure is extremely simple, and the number of parts of the device can be reduced. Not only can the number of devices be reduced and the device can be manufactured inexpensively, but also the device can be downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 1 is a plan view showing a supporting structure of a pressing roller of a paper feed roller pair, FIG. 2 is an enlarged view of part A of FIG. 1, and FIG. Enlarged view of part B of FIG. 1,
FIG. 4 to FIG. 6 are side views showing the operation associated with the rotation of the support shaft. FIG. 7 is a side view schematically showing an example of a printer to which the present invention is applied, FIGS. 8 and 9 are side views showing a structure for switching a movable guide by a pivoting operation of a support shaft, FIG. FIG. 11 is a side view showing another structure for switching the movable guides by the pivotal movement of the support shaft, and FIG. 12 is a side view showing the structure for connecting and disconnecting the drive system of the pin drive device by the pivotal motion of the support shaft. . In the figure, 4: paper feed roller pair, 7: movable guide 41: receiving roller, 42: support shaft 43: arm, 44: press roller 47: secondary pressure spring, 51: mooring end of pressure spring 52: with Pressure pin, 54: Pressure release pin 74: Piece, 76: Path switching pin

Claims (2)

[Claims] 1. A receiving roller (41) pivotally mounted at a fixed position and an arm (43) pivotally attached to the tip of the arm (43), and abuts and separates from the receiving roller by swinging of the arm around a support shaft (42). In the paper feed roller pair (4) including the pressing roller (44),
The arm (43) is pivotally attached to the support shaft (42) so as to be relatively rotatable,
A secondary pressure spring (47) for increasing the pressure applied to the presser roller (44) is provided with its mooring end (51) facing the peripheral surface of the support shaft (42), and the support shaft (42) is pressed down. When the roller is rotated in the pressure direction, the pressure pin (52) and the support shaft (42) that are linked to the mooring end (51) of the secondary pressure spring are linked to the arm (43) by the rotation in the opposite pressure direction. A pressure release pin (54) is provided,
In the intermediate rotation region of the support shaft (42), the mooring end (51) of the secondary pressure spring, the pressure spring (52), the arm (43) and the pressure release pin (54) are not linked together. A characteristic pressure switching mechanism for a pair of paper feed rollers in an information input / output device. 2. An information input / output device comprising a movable guide (7) for switching a medium path, wherein a piece (74) contacting the movable guide is rotatable relative to a support shaft (42) according to claim 1. A path switching pin (76) which is mounted and which comes into contact with and separates from the frame in accordance with the pivotal movement of the support shaft (42) is planted on the support shaft (42). The pressure switching mechanism for the pair of paper feed rollers described in 1.