JPH1120960A - Paper sheet feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To feed a paper sheet by preventing the occurrence of wrinkles and reducing friction resistance as much as possible. SOLUTION: By operating a one-way lever 48 and a ratchet lever 51 in synchronization with a feed roller, first, a hopper 2 is raised from a fixed position to a feeding position by a lift lever 3, then lowered slightly by an amount δto move a paper sheet away from the feed roller 4 and thereby feeding resistance is reduced, and lastly the hopper 2 is lowered to the fixed position by apply a braking force with a suppressing unit 80.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sheet feeding device, and more particularly, to a mechanism for moving a hopper up and down for sheet feeding.

[0002]

2. Description of the Related Art In general, a paper feeder provided in a printer or the like so as to sequentially feed stacked sheets to a recording / writing section lifts a hopper on which sheets are stacked so that the uppermost sheet can always be fed. The configuration is such that the paper is held in a state, and at the time of paper feeding, the paper feeding roller is lowered to draw out the top sheet.

However, in such a sheet feeding device, not only can the sheet be replenished unless the sheet cassette is pulled out each time, but also the sheet is fed due to friction between the second and subsequent sheets. However, there is a disadvantage that a large paper feeding load is applied to pulling out the uppermost sheet.

On the other hand, in order to reduce such a load, the hopper is lowered at the same time as the sheet is fed, because a large step is formed between the leading end and the trailing end of the sheet being fed. If you are using thin paper,
Inconveniences such as wrinkling of the sheet due to contact with the second and subsequent sheets occur.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
To provide a new paper feeding device capable of minimizing paper feeding load and paper wrinkling during paper feeding, and also capable of replenishing paper with a hopper or the like loaded. It is in.

[0006]

That is, according to the present invention, as a paper feeding device for achieving the above object, there is provided a member on which a sheet is placed, and recording and writing of the sheet on the sheet placing member one by one. The sheet feeding roller that feeds the sheet, and the sheet feeding member is raised during the one sheet feeding operation of the sheet feeding roller to a position where the sheet can be fed, and then the sheet placing member is lowered to a position where the sheet is separated from the sheet feeding roller And a lifting / lowering means for lowering the paper placing member to a fixed position via the control unit. Further, the lifting / lowering means acts on the lifting / lowering means to apply a braking force when the paper placing member is lowered to the fixed position. Further, a damper means for providing a mechanism for lowering the paper placing member to a position for separating the paper placing member from the paper feed roller under a non-braking state is provided to the damper means.

[0007]

Embodiments of the present invention will be described below. The drawings all show one embodiment of the present invention.

FIG. 1 shows a series of wheel trains in which the hopper 2 is moved up and down in conjunction with the rotation of the paper feed roller 4.
As shown in FIG. 2, the wheel train configuration is roughly divided into a feed roller drive train wheel I for transmitting a driving force to the feed roller 4 and a lift arm drive train wheel II for rotating the lift arm 3.
And a first and second lever operation system for operating the ratchet trigger lever 69, the one-way lever 48, and the ratchet lever 51 so that the lift arm 3 performs a required turning operation at a required timing together with the operation of the paper feed roller 4. It is composed of wheel trains III (FIG. 4) and IV, and a suppression unit 80 that suppresses a rapid downward movement of the hopper 2.

Next, the respective wheel trains I to IV and the suppression unit 80 will be described in the following order. As shown in FIG. , A driving force transmission gear 9 meshing with the pinion 6 on the shaft of the sheet feeding motor 5, an intermediate transmission gear 11 meshing with the driving force transmission gear 9 via the intermediate gear 10, and this gear 11
This intermediate transmission gear is connected to a gear (not shown) integral with the paper feed roller 4 via an intermediate gear meshing with the gear, so that the paper feed roller 4 having a D-shaped cross section makes one rotation in the normal rotation cw direction for each paper feed. 11 is configured to be operated by a clutch mechanism (not shown).

A lift arm drive train II is also shown in FIG.
As shown in FIG. 7, the lift arm 3 is pivoted upward by a sector gear 32 which branches off from the driving force transmission gear 9 and engages with a pinion 31 integral with a large gear 30 described later by the reverse rotation ccw of the paper feed motor 5. It is configured as follows.

That is, the sun gear 21 meshing with the feed roller driving gear 9 via the intermediate gear 20 transmits only the reverse rotation ccw of the feed motor 5 coaxially with the ratchet wheel 26 in cooperation with the planetary gear 22. The gears 25 are transmitted to the gear 25, and further meshed with a one-way gear 50 to be described later.
A large gear 30 is driven by a regulating gear 28 which is allowed to rotate only in a direction, and a lift arm which is integral with the gear 30 through a sector gear 32 meshing with a pinion 31 integral with the large gear 30 as shown in FIG. 3 is configured to pivot upward.

As shown in FIG. 11, the transmission gear 25 has a ratchet by engaging an engaging projection 25a provided on a part of the peripheral surface thereof with an arcuate slit 26a provided on the ratchet wheel 26. When the wheel 26 is locked by the ratchet lever 51, the wheel 26 rotates within a range of 90 ° so that the hopper 2 can be lowered a little δ, preferably about 5 mm, from the sheet feeding position. . In FIG. 3, reference numerals 23, 24, and 27 indicate intermediate gears, respectively.

By the way, of the two lever operating trains III and IV, one of the lever operating trains IV is
The operation of engaging and disengaging the ratchet lever 51 with the ratchet wheel 26 and the operation of engaging and disengaging the one-way gear 50 with the regulating gear 28 in conjunction with the rotation of the paper feed roller 4 are performed.

The wheel train IV meshes with a gear (not shown) integral with the paper feed roller 4 via intermediate gears 41 and 42, and a drive pulley 43 that rotates in synchronization with the paper feed roller 4, and a timing belt 44. And a driven pulley 45 that is driven and rotated through the driving pulley 43, and first and second cams 46 and 47 that are integrally attached to the shaft. By swinging the one-way gear lever 49 held at the tip of the lever 48, the one-way gear 50 rotatably supported only at one end in the direction indicated by the arrow in FIG. While being disengaged from the gear 28, the ratchet lever 51 is swung by the first cam 46,
The latch claw 51c is configured to be disengaged from the ratchet gear 26.

On the other hand, the other lever operating train wheel II
I is a wheel train for operating a ratchet trigger lever 69 acting on the one-way lever 48 and the ratchet lever 51 during printing in order to simultaneously drive a paper feed mechanism for printing. The movement of the wheel train III needs to be described with reference to FIG. 4 together with FIG. 5 showing the paper feed mechanism.

A first sun gear 61 meshing with the driving force transmission gear 9 via the intermediate gear 20 is meshed with two planetary gears 26A, 62B supported by a common rod 63. The rotation is transmitted to the second sun gear 64 via the planetary gear 62A by the counterclockwise rotation ccw of the gear 61 and via the planetary gear 62B by the clockwise rotation cw.

The second sun gear 64 transmits the rotation to the third sun gear 67 via the intermediate gear 65, while the first sun gear 61 is rotated counterclockwise ccw via the planetary gear 66 meshing therewith. 4A, the rotation is applied to the sub-roller gear 68 in the counterclockwise direction ccw as shown in FIG.
And further, as shown in FIG. 5, the paper from the paper feed roller 4 is conveyed to the printing unit by the sub paper feed roller 77 on this shaft.

The third sun gear 67 meshes with two planetary gears 71A and 71B supported by a common rod 72, and the first sun gear 61 rotates counterclockwise ccw. In this case, by rotating the load roller gear 73 configured as a toothless gear in a fixed angle counterclockwise ccw,
The ratchet trigger lever 69 is swung by a cam 74 that rotates integrally with the cam 74, and the ratchet lever 51 and the one-way lever 48 are moved to the first position while the sub-paper feed roller 69 is rotating, that is, during the printing period. , And are separated from the second cams 46 and 47.

A cam (not shown) for operating the load roller is connected to the load roller gear 73 via an intermediate gear.
As shown in FIG. 5, the first and second load rollers 75 and 76 disposed around the sub paper feed roller 77 are pressed against the peripheral surface of the sub paper feed roller 77 and fed from the paper feed roller 4. The fed paper is fed to a main paper feed roller 78, and after being fed, these load rollers 75,
The main paper feed roller 78 moves the paper fed by a paper feed motor (not shown) one by one by separating the paper feed load from the sub paper feed roller 77 to reduce the paper feed load. It is configured to intermittently feed the printing unit line by line.

On the other hand, the above-mentioned suppressing unit 80 suppresses the generation of the impact sound by gently lowering the hopper 2, and as shown in FIG. Drive pinion 3
It is configured as a kind of dashpot provided in the vicinity of 1.

That is, the suppression unit 80 is formed by meshing a gear 81 provided with a large rotational resistance by a high-viscosity oil or a spring sealed in a housing 82 with a sector gear through an intermediate gear 86 and a drive pinion 31. , The lowering speed of the hopper 2 is suppressed, and the housing 8 supporting the gear 81 at the center thereof is also provided.
By pivotally supporting the substrate 83 with the fulcrum pin 84 so that the hopper 2 can be slightly swung, when the hopper 2 is slightly lowered from the sheet feeding position by a small amount δ, the hopper 2 can be quickly lowered without applying resistance. The reference numeral 85 in the figure denotes a stopper for restricting the swing of the housing 82.

Next, a series of sheet feeding operations performed by the above-configured apparatus will be described with reference to FIG. The paper feed motor 5 is stopped during the recording and writing on the paper, and FIG.
As shown in FIG.
, The ratchet trigger lever 69 is rotated clockwise in the figure around the fulcrum 70 by a cam 74 integral therewith, and the operation protrusions 48a of the one-way lever 48 and the ratchet lever 51 are moved by the tip. , 51
a, and these are turned around the fulcrum counterclockwise in the drawing to separate them from the first and second cams 46 and 47.

In this state, the ratchet wheel 26 is not restrained by the ratchet lever 51, and the ratchet wheel 26 is engaged with the arc-shaped slit 26a.
a, the transmission gear 25 engaged with the ratchet wheel 26 can also rotate, so that the intermediate gear 27,
Since the pinion 31 integral with the regulating gear 28 and the large gear 30 is also in a rotatable state, the hopper 2 moves the lift arm 3 and the sector gear 32 integral therewith by the weight of the loaded paper, And lowered to the home position, that is, the lower end position.

In this state, when a feed preparatory signal is input next, the feed motor 5 is first rotated at the time point a.
4A, as shown in FIG. 4A, the first sun gear 61 meshing with the driving force transmission gear 9 via the intermediate gear 20 is reversed ccw, and one of the planetary gears meshing with this. The second sun gear 64 is rotated in the counterclockwise direction ccw via 62A, and the planetary gear 66 meshing with the second sun gear 64 meshes with the sub-paper feed roller gear 68, and the sub-paper feed roller 77
Is rotated in the counterclockwise direction ccw, the load roller gear 73 is connected to the third sun gear 67 via the intermediate gear 65, and the planetary gear 71A meshed with the third sun gear 67, as shown in FIG.
As shown in FIG. 5, the reverse rotation ccw is made approximately 200 °, and at the time point b, the ratchet trigger lever 69 is rotated counterclockwise by the cam 74 integrated therewith to release the lock between the one-way lever 48 and the ratchet lever 51. These cam followers 46b and 47b are connected to the first and second cams 4 respectively.
6 and 47. During this period, since the clutch is disengaged and the driving force is not transmitted to the feed roller driving gear 11, the feed roller 4 is in a stopped state.

When the paper feed motor 5 is again rotated reversely ccw at the time point c after the stop, the driving force is transmitted to the paper feed roller drive gear 11 via the clutch. As a result, the sheet feeding roller 4 having a D-shaped cross section starts rotating in the sheet feeding direction from the stop position with the flat surface facing down in the counterclockwise direction in the drawing, and stops once at a time point d when the sheet feeding roller 4 rotates about 100 °.

On the other hand, due to the reverse rotation ccw of the paper feed motor 5, a drive pulley 43 which rotates in synchronization with the paper feed roller 4 via the lever operation train wheel IV, ie, the intermediate gears 41 and 42.
And driven pulley 45 and first and second cams 4 integrated therewith
6 and 47 are also rotated, and as shown in FIG. 10, the one-way lever 48 is rotated clockwise in the figure by the first cam 46 to release the lock of the one-way gear lever 49. The gear 50 meshes with the regulating gear 28 so that it can rotate only clockwise in the figure,
The ratchet lever 51 is rotated counterclockwise in the figure by the second cam 47 to release the temporarily locked ratchet wheel 26.

On the other hand, when the paper feed motor 5 is switched to the normal rotation cw at the time point d, as shown in FIG. 4B, the clockwise direction cw from the first sun gear 61 via the lever operation train wheel III is reached.
The load roller gear 73 which has received the rotation of (1) presses the first and second load rollers 75 and 76 against the sub-paper feed roller 77 via a cam (not shown), and the paper can be fed to these rollers. At the same time, the sun gear 2 meshing with the lift arm drive train wheel II, that is, the feed roller drive gear 9
1, a planetary gear 22, a transmission gear 25 coaxial with the ratchet wheel 26, a large gear 30 coupled thereto through an intermediate gear 27 and a regulating gear 28, and a sector gear 32 formed by a pinion 31 integral therewith. When the paper feed roller 4 is rotated clockwise and stopped temporarily,
The hopper 2 is lifted by the lift arm 3 integrated with the sheet, and the uppermost sheet placed thereon is pressed against the sheet feed roller 4.

Then, at time point e, the paper feed motor 5 is switched to the reverse rotation ccw, and the paper feed roller 4 is rotated again from the stop position, so that the uppermost sheet that is in contact with the peripheral surface of the sub paper feed roller 77 Then, at the time point f when the paper feed roller 4 rotates about 180 °, the paper feed motor 5 is switched to the normal rotation cw again to stop the paper feed roller 4.

On the other hand, due to the reverse rotation ccw of the sheet feeding motor 5 at the time point e, the driven pulley 45 connected to the lever operation train wheel IV rotates the second cam 47 integrated therewith, as shown in FIG. Then, the pawl 51c of the ratchet lever 51 which is in sliding contact with the peripheral surface is engaged with the teeth of the ratchet wheel 26 to be locked.

Then, at the next time point f, the sheet feeding motor 5 is switched to the normal rotation cw, and when the transmission of the driving force to the sector gear 32 by the lift arm drive train II is cut off, the weight of the loaded sheet acts. The hopper 2 applies a counterclockwise torque in the figure to the lift arm 3 and the sector gear 32 integral therewith, and applies this torque to the pinion 31 meshing with the sector gear 32, the large gear 30 integral therewith, and the regulating gear The transmission gear 25 is transmitted to the ratchet wheel 26 via the engaging projection 25a which engages with the circular slit 26a of the ratchet wheel 26 via the intermediate gear 27 and the intermediate gear 27.

Then, at the time point g, the one-way lever 48 rotated by the second cam 46 which continues to rotate.
However, as shown in FIG.
The one-way gear 50 and the regulating gear 28 are disengaged via the transmission gear 25 to allow the regulating gear 28 to rotate freely.
Is displaced in the counterclockwise direction from the position shown by the two-dot chain line in FIG. 11 to the position shown by the solid line in the counterclockwise direction corresponding to the length of the arc-shaped slit 26a. 26, the hopper 2 is lowered by a small amount δ, preferably by about 5 mm, and a gap is formed between the sheet being pulled out by the feed roller 4 and the second and subsequent sheets. To reduce the frictional resistance acting on the paper.

The counterclockwise rotating force of the sector gear 32 tends to rotate the gear 81 pivotally supported by the suppressing unit 80 via the pinion 31 and the intermediate gear 86 in the clockwise direction. In addition, while the gear 81 is provided with a large rotational resistance, the suppression unit 80
Is pivotally supported by a fulcrum pin 84 so that it can be slightly rotated. The turning force applied to this gear 81 displaces the suppression unit 80 in the direction of the arrow in FIG. Lower it.

Then, at time h following this, the sheet feeding motor 5
Is switched to the reverse rotation ccw, and the paper feed roller 4 is rotated again. When the paper feed roller 4 is released from contact with the second and subsequent papers, the uppermost paper is released from the sub paper feed roller 77 without load. At the time point i after the rotation of 360 °, the feed motor 5 stops when the forward rotation cw is switched.

On the other hand, the driven pulley 45 rotates the second cam 47 to rotate the ratchet wheel under the condition that the rotational driving force to the sector gear 32 is not transmitted by the switching of the normal rotation cw of the sheet feeding motor 5. The engagement between the ratchet lever 26 and the ratchet lever 51 is released. For this reason, at time j, the hopper 2 on which the sheet is placed rotates the lift arm 3 in the counterclockwise direction in FIG.
And a series of gears meshing therewith is rotated in the reverse direction and descends to the home position, that is, the lowermost position.

By the way, the sector gear 32 is engaged with the gear 81 on the suppression unit 80 to which a large rotational resistance is applied via the pinion 31 and the intermediate gear 86, so that the sector gear 32 receives a large braking force. The hopper 2 is rotated gently, and the hopper 2 is gently landed without generating an impact sound, thus completing a series of sheet feeding operations.

Although the above description has been made with reference to the example of the paper feeding mechanism of the printer, the present invention can be applied to other apparatuses such as a copying machine which requires the paper feeding mechanism.

[0037]

As described above, according to the present invention, during one sheet feeding operation of the sheet feeding roller, the placing member is raised to the sheet feeding position and then separated from the sheet feeding roller. Since the loading member is lowered to the home position, the top sheet is brought into contact with the paper feed roller and sent out, and then the other paper is separated from the paper feed roller. Moreover, it is possible to feed the paper without applying a load resistance to the paper, so that accurate recording and writing can be realized. Paper can be replenished without pulling out the paper tray or the like, and the remaining amount of paper can be detected using a simple detector.

Further, since a braking force is applied to the lifting / lowering means when the mounting member is lowered, it is possible to suppress the generation of an impact sound when the mounting member returns to the home position, and at the same time, to supply the power. When the paper roller is separated from the paper roller, it is lowered under no braking, so that the separation operation during paper feeding can be performed quickly, and the time required for paper feeding can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an all-wheel train mechanism of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement of each transmission train in the apparatus.

FIG. 3 is a diagram showing a lift arm drive train and a first lever operating train in the above device.

FIGS. 4 (a) and 4 (b) are views showing a second lever operation train of the above device together with its movement.

FIG. 5 is a diagram showing a paper feed mechanism operated by the lever operation train wheel.

FIG. 6 is a diagram showing a suppression unit in the same device.

FIG. 7 is a view showing a lifting mechanism of a lift arm in the same device.

FIGS. 8 (a) and 8 (b) are diagrams showing one operation of the above device and its main part.

FIG. 9 is a diagram showing a next operation of the above device.

FIG. 10 is a diagram showing a next operation of the above device.

FIGS. 11 (a) and (b) are diagrams showing the next operation of the above-mentioned device and its main part.

FIG. 12 is a diagram showing a further operation of the above device.

FIG. 13 is a diagram showing a next operation of the above device.

FIG. 14 is a diagram showing an operation timing.

[Explanation of symbols]

 2 Hopper 4 Feed roller 3 Lift arm 5 Feed motor 9 Driving force transmission gear 25, 26 Ratchet wheel 32 Sector gear 46, 47 Cam 48 One-way lever 49 One-way gear lever 51 Ratchet lever 68 Sub-paper feed roller gear 69 Ratchet trigger lever 73 Load roller gear 75, 76 Load roller 77 Sub-paper feed roller 80 Suppression unit I Feed roller drive train wheel train II Lift arm drive train wheel train III First lever operation train wheel train IV Second lever operation train wheel train

Claims (4)

[Claims] A sheet-supplying member, a sheet-supply roller for sending out sheets on the sheet-supplying member one by one to a recording / writing unit, Lifting and lowering means for lowering the paper mounting member to a fixed position through an operation of raising the mounting member to a position where paper can be fed, and then lowering the mounted paper to a position separated from the paper feeding roller; Paper feeder. 2. The sheet feeding device according to claim 1, wherein the lifting / lowering means is driven by a driving means in synchronization with the sheet feeding roller. 3. The sheet feeding device according to claim 1, further comprising damper means for acting on said elevating means to apply a braking force when said sheet placing member is lowered to a fixed position. 4. A mechanism according to claim 1, wherein said damper means is provided with a mechanism for lowering said sheet placement member to a position for separating said sheet placement member from said sheet supply roller under a non-braking state. Paper feeder.