JPH0720718B2 - Pressure setting mechanism for paper feed roller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for an electronic computer, and is provided with a paper feed roller for nipping and feeding paper and a tractor for feeding paper by pin feeding. The present invention relates to a mechanism for automatically setting the pressure applied to the paper feed roller during the single-cut processing and the continuous form processing.

<< Prior Art >> FIG. 11 is a side view showing an automatic setting mechanism of the pressure applied to the feed roller in a conventional printer.

Reference numeral 5 in the figure denotes a control shaft that is axially supported immediately below the platen 2 at a fixed position, and a cam 7 is fixed to one end of the control shaft. Cam 7
Has two stages of protrusions 61 and 62 on its outer circumference. The driven rollers 8b and 9b of the paper feed rollers 8 and 9 are pivotally attached to the tips of arms 13 and 14 fixed to support shafts 11 and 12 which are mounted in stationary positions. First links 63 and 64 extending downward are fixed to one ends of the support shafts 11 and 12, and forks 65 and 66 are attached to the lower ends thereof.
Are formed. Below the first links 63 and 64, the L-shaped second link 6 is swingable around the pins 67 and 68 in the non-moving position.
9 and 70 are provided. Cam followers 71, 72 facing the cam are provided at one ends of the second links 69, 70, and pins 73, 74 are planted at the other ends thereof. The pins 73, 74 are forks 65, 66 of the first link. Engage with a large play. 75, 76
Is a tension spring mounted between the second links 69, 70 and a frame (not shown), and the driven rollers 8b, 9b are pressed against the drive rollers 8a, 9a by this spring.

The control shaft 5 is rotationally controlled by a pulse motor (not shown). In the state shown in FIG. 11, the cam followers 71 and 72 are separated from the peripheral surface of the cam 7 and the driven rollers 8b and 9b are biased by the springs 75 and 76. In the state of being strongly pressed by the drive rollers 8a and 9a, the single-sheet feeding state is set. When the cam 7 rotates and the lower stepped portion 61 and the cam followers 71 and 72 come into contact with each other, the pins 73 and 74 at the connecting portion of the first and second links are located in the play gaps of the forks 65 and 66. Therefore, the urging force of the springs 75 and 76 is not transmitted to the first link, and the driven rollers 8b and 9b come into contact with the drive rollers 8a and 9a by their own weight only, and the continuous book press-feeding state is established. When the cam 7 further rotates and the cam followers 71, 72 come into contact with the higher stepped portion 62, the pin 73 of the link connecting portion,
74 pushes the forks 65 and 66 to the platen 2 side, the driven rollers 8b and 9b are separated from the drive rollers 8a and 9a, and the continuous form is pulled and fed and the sheet is inserted.

<< Problems to be Solved by the Invention >> In the structure described above, the tension of the driven rollers is exerted by the tension springs 75, 76 mounted between the second links 69, 70 and the frame (not shown). Is applied as a twisting force from one side of the support shafts 11 and 12, so the pressure applied by the rollers is increased by the torsional deformation of the support shafts 11 and 12 that are long in the paper width direction and the bending deformation of the roller shaft due to the reaction force from the rollers. However, there is a problem in that the feeding of the paper becomes unstable because the adjustment becomes uneven in the direction, a large number of man-hours are required for the adjustment, and the pressing force fluctuates greatly even with a small adjustment error.

An object of the present invention is to obtain a driven roller pressing force setting mechanism that solves the above problems.

<< Means for Solving the Problem >> In the present invention, the driven rollers 8b, 9b arranged above the driving rollers 8a, 9a are driven downward by a plurality of springs 15, 16 arranged in the longitudinal direction of the support shafts 11, 12. With a structure in which pressure is applied to the rollers, cam shafts 17 and 18 parallel to the support shafts 11 and 12 are installed below the arms 13 and 14 that support the driven rollers 8b and 9b, and springs 15 and 16 are attached to the cam shafts. First cams 19 and 20 for pushing downward and second cams 21 and 22 for pushing arms 13 and 14 upward are provided, and the cam shafts 17 and 18 are rotated to follow driven rollers 8b and 9b. Adopts a structure that changes the pressure applied to.

<< Operation >> The driven rollers 8b and 9b are provided with a uniform pressing force in the paper width direction by the plurality of springs 15 and 16 arranged in the longitudinal direction of the support shaft. FIG. 3 shows the single-sheet feeding state in which the driven rollers are pressed by the springs 15 and 16. From this state, the camshaft 17
When the 18 is rotated, first the first cams 19 and 20 are moved to the springs 15 and 16.
It contacts with and pushes it up, and the continuous book pushing and feeding state shown in FIG. 4 is obtained. In this state, the second cams 21 and 22 are not in contact with the arms 13 and 14, so that the driven rollers 8b and 9b are not in contact with each other.
Is a drive roller 8a due to the weight of the arms 13 and 14 and the rollers.
It is in contact with 9a. When the cam shafts 17 and 18 are further rotated from this state, the second cams 21 and 22 come into contact with the arms 13 and 14 and push them up, and the driven rollers 8b and 9b are driven by the drive rollers 8a and
Separated from 9a, pulling and feeding the continuous book. Paper insertion is also performed in this state.

The illustrated embodiment employs a structure in which the rotation of the cam shafts 17 and 18 is rotated in synchronization with the control shaft 5 arranged below the platen 2, and is driven in synchronization with the print gap adjustment when the paper is inserted. The rollers 8b and 9b are brought into contact with each other at a distance. Further, in the illustrated embodiment of the apparatus, the paper discharge side guide
50 and the paper feed switching guide 49 on the paper insertion side to the cam shaft 17,
A structure in which the switching cams 41 and 42 mounted on the 18 are used to swing the structure is adopted so that various operations at the time of paper switching can be performed simultaneously by a single pulse motor 27.

<Embodiment> FIGS. 1 to 10 show an embodiment of the present invention, and FIG. 1 is a side view of a pressure setting mechanism of a paper feed roller of a printer. In the figure, 1 is a print head, 2 is a platen, 3 is a cam follower mounted on a platen shaft 4, 5
Is a control shaft axially supported immediately below the platen 2, 6 is a pulley fixed to one end of the control shaft 5, 7 is a cam fixed to both ends of the control shaft 5, and 8 and 9 are paper feed rollers. . The platen 2 is axially attached to the tip of an arm 10 that is swingably provided on a drive roller shaft of a paper feed roller 9, and is moved up and down by a cam 7 of a control shaft 5 according to the paper thickness.

The drive rollers 8a and 9a of the paper feed roller are axially supported in a non-moving position by a frame (not shown). The platen 2 and the drive rollers 8a and 9a are linked by a timing belt (not shown), and are synchronously driven by a pulse motor that rotates forward and backward. The driven rollers 8b and 9b are arms supported by support shafts 11 and 12 mounted on a frame (not shown).
It is axially supported by the tips of 13 and 14, and is biased toward the drive rollers 8a and 9a by spiral springs 15 and 16 (see FIG. 2).
Reference numerals 17 and 18 denote cam shafts 19 to 22 which are provided below the arms 13 and 14 in parallel with the support shafts 11 and 12, and are fixed to the cam shafts 17 and 18. The first cams 19 and 20 are cam shafts. The second cams 21, 22 are arranged below the springs 15, 16 whose base ends are wound, and the second cams 21, 22 are arranged below the arms 13, 14. 23 is a gear fixed to one end of the cam shaft 17, 24 is an intermediate gear meshing with the gear 23, 25 is a pulley integrated with the intermediate gear 24, 26 is a pulley fixed to one end of the cam shaft 18, and 27 is a pulley. Pulse motor, 28 is a pulley
It is a timing belt mounted on 25, 26 and a motor 27.

Here, the paper feed roller 8 shown in FIG. 1 is the same as the paper feed roller 9 except that it has the gear trains 23 and 24. Therefore, only the paper feed roller 9 will be described below, and the paper feed roller 8 will be described. Omit it. As shown in FIG. 2, in the paper feed roller 9, two spiral springs 16 are arranged along the longitudinal direction of the driven roller shaft, and apply a uniform pressing force to the driven rollers 8b and 9b in the paper width direction. ing. The first cam 20 is provided directly below the spring 16 and the second cam 22 is provided directly below the arm 14, so that the first cam 20 and the second cam 22 are at different timings. Push 14

Next, the setting operation of the pressing force of the paper feed roller having the above configuration
This will be described with reference to the flowcharts of FIGS. 5 to 6 and FIG.

When the printing process is instructed, the control asks at step 30 the type of paper used. When the single-cut processing is instructed, the control shaft 5 is rotated in step 31 and set in the state shown in FIG.
By repeating, the line feed and the print process are repeated to perform the print process. At this time, the paper feed rollers 8 and 9 firmly hold the paper.

If continuous form paper is ordered in step 30,
As for control, in step 35, another push-feeding and pull-feeding are asked. When the push-feeding is instructed in step 35, the control shaft 5 rotates the cam 20 to the position shown in FIG. 4 and pushes the spring 16 upward in step 36. The driven rollers 8b and 9b are driven by the drive rollers 8a,
9A is weakly contacted, and in this state, steps 32 to 34 are repeated, and the printing process is performed while the paper is being fed by the synchronous reverse rotation of the tractor (not shown) and the paper feed rollers 8 and 9.

During this push-in continuous book processing, the continuous book paper is fed by the tractor, and is held between the paper feed rollers 8 and 9 in the vicinity of the printing area so that the feeding force is also applied from the paper feed rollers. The specified paper feed is performed. Further, since the feeding force applied from the paper feed rollers 8 and 9 is small,
The feeding accuracy is regulated by the tractor, and accurate feeding is performed. Even if there is a difference in the feeding amount between the tractor and the paper feed rollers 8 and 9, damage to the marginal punch holes does not occur.

When a command for pulling and feeding the continuous book is issued in step 35, the control shaft 5 rotates the cam 20 in the position shown in FIG. 5 in step 37. Due to the swing of the cam 22, the driven rollers 8b and 9b are separated from the drive rollers 8a and 9a. In this state, steps 32 to 34 are repeated until the platen 2 and the paper feed rollers 8 and 9 are
Also, the tractor is rotated in the normal direction to perform the printing process while feeding the paper. At this time, the driven rollers 8b and 9b are
Since they are separated from a and 9a, the drive rollers 8a and 9a simply rotate, and all the sheet feeding force is given from the tractor.

7 to 10 show a structure in which the paper passage is switched in association with the change in the pressing force of the paper feed roller. In the figure, 41 and 42 are switching cams fixed to the cam shafts 17 and 18, 43 and 44 are fulcrum shafts installed along the cam shafts 17 and 18, and 45 and 46 are fixed to one end of the fulcrum shafts 43 and 44. Rocking levers, 47 and 48 are cam followers pivotally attached to the ends of the levers 45 and 46, 49 is a paper feed switching guide fixed to the fulcrum shaft 43, and 50 is a paper ejection changeover fixed to the fulcrum shaft 44. Be a guide.

FIG. 7 shows a single-sheet feeding state, in which the paper feed rollers 8 and 9 are in the state shown in FIG. Switching cam 41
Due to the action of, the paper feed switching guide 49 is downward (falling down)
, The cut sheet automatic paper feed passage 52 is open. On the other hand, the sheet discharge switching guide 50 is located above (upright), and the single sheet discharge passage 53 connected to a stacker (not shown) is open.

FIG. 8 shows the cam shaft shown in FIG. 7 slightly rotated.
19 and 20 are not yet in contact with the springs 15 and 16, so that the paper feed rollers 8 and 9 remain in the state shown in FIG. In this state, the swing lever 45 is rotated by the action of the switching cam 41, and the sheet feeding switching guide 49 closes the single sheet feeding passage 52.
This kind of operation is performed after printing cut sheets and then
This is done when sending back to 54.

FIG. 9 shows a further rotation of the cam shafts 17 and 18 by driving the pulse motor 27. The cam 20 pushes the spring 16 upward so that the paper feed roller pushes the continuous book feed feeding shown in FIG. It becomes a state. At this time, the paper feed switching guide 49 is located above and the single-cut sheet automatic feed passage 52 is still closed, and the action of the switching cam 42 causes the paper ejection switching guide 50 to change its direction downward to eject the single-cut sheet. The passage 53 is closed and the continuous paper discharge passage 55 is opened. The tractor for feeding the continuous paper is on an extension of the continuous paper discharge passage 55. The continuous form paper is pushed in and inserted from the continuous form paper discharge passage 55, and is discharged from the manual feed passage 54.

In FIG. 10, the cam shafts 17 and 18 are further rotated from the state shown in FIG. 9, and the paper feed rollers 8 and 9 are in the state shown in FIG. The paper feed switching guide 49 is turned downward by the action of the cam 41 to open the single-cut automatic paper feeding passage 52, and the paper ejection switching guide 50.
Remains in the lower position. Consecutive paper is a manual passage
It is supplied from the sheet 54 and is discharged to the continuous paper sheet discharge passage 55 through the print area. Further, in this state, the manually fed single-cut sheet and the continuous-feed sheet to be fed by pulling are fed from the manual-feed passage 54, the automatically fed single-cut sheet is fed from the single-sheet automatic paper feed passage 52, and the continuous-feed sheet to be pushed and fed. Paper can be inserted from the continuous paper discharge passage 55.

<< Effects of the Invention >> As described above, in the pressing force setting mechanism of the present invention, since a plurality of springs are arranged on the support shaft of the driven roller, it is possible to prevent torsional deformation of the support shaft and bending deformation of the roller shaft. As a result, a stable pressure can be applied to the paper feed roller, the applied pressure can be easily adjusted, and a stable paper can be fed. Further, since the spring and the arm provided with the two cams having different timings are separately pushed, the pressing force of the driven roller can be changed reliably.

[Brief description of drawings]

FIG. 1 is a side view of the pressure setting mechanism for the paper feed roller, and FIG.
FIG. 3 is a perspective view of one paper feed roller, FIG. 3 is a sectional view of a portion A of FIG. 2 showing the paper feed roller in a single-sheet feeding state, and FIG. The same sectional view showing,
FIG. 5 is a cross-sectional view showing the paper feed roller in a continuous form pulling feeding and paper insertion state, and FIG. 6 is a control flowchart,
FIG. 7 is a side view showing the state of the switching guide for the single-sheet feeding state, FIG. 8 is a side view showing the switching guide for the single-sheet feeding back state, and FIG. FIG. 10 is a side view showing a guide for pulling and feeding a continuous book and a switch for inserting a sheet, and FIG. 11 is a side view showing a conventional example. In the figure, 8 and 9: paper feed roller, 8a and 9a: drive roller 8b and 9b: driven roller, 13 and 14: arm 15, 16: spiral spring, 17 and 18: cam shaft 19, 20: first cam , 21, 22: second cam

Claims (1)

[Claims] 1. A driving roller (8a), (9a) and a driven roller (8b), (9b) pressed against the driving roller (8a), (9b), wherein the driven roller (8b), (9b) is a driving roller (8a), In the paper feed rollers (8) and (9) of the printer located above (9a), the lower driven roller (8) and (9) are driven by the upper driven roller by a plurality of springs (15) and (16) arranged in the paper width direction. The cam shafts (17), (8) are parallel to the driven roller shaft below the arms (13), (14) that are pressed against the 8a) and (9a) sides and support the driven rollers (8b), (9b). 18) is installed and a spring (1
The first cams (19), (2) that push 5), (16) upwards
0) and second cams (21), (22) for pushing the arms (13), (14) upward, and the first cams (19),
(20) and the second cams (21), (22) press the springs (15), (16) and the arms (13), (14) at different timings. Pressure setting mechanism with feed roller.