JPH02204225A - Sheet supply/sending device - Google Patents

Abstract

PURPOSE:To reduce working sound at up and down movement of an intermedi ate plate and prolong the life of a clutch by pushing up a sheet feeding means into a sheet feeding range due to elevating of the intermediate plate, when the elevatably supported sheet feeding means is detected to be under the feeding range of sheet. CONSTITUTION:When a paper deck is inserted to a paper sheet feeding position, a pin 87 makes a micro switch 86 ON, a clutch 93 is brought to be ON, the driving force from a motor 89 is transmitted to an input gear 71, chains 73, 75 are rotated clockwise, and an intermediate plate 56 is elevated. The upper most sheet S pushes up a pick-up roller 57, and a part of a supporting plate 103 makes a sheet height sensor 109 ON. After passing a prescribed time, the clutch 93 is brought to be OFF, the motor 89 is stopped, and the elevation of the intermediate plate 56 is ended. When the paper feeding is proceeded and the pick-up roller 57 descends up to the lower limit position, the part of the supporting plate 103 is separated from the sensor 109, the sensor 109 is OFF, the clutch is ON, and the intermediate plate 56 is elevated, similar to the foregoing.

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a sheet feeding device used in image forming apparatuses such as copying machines, printing machines, and laser beam printers. The present invention relates to a sheet feeding device including a sheet storage device, a sheet feeding device, and a lifting device.

(B) Conventional technology Conventionally, there have been known sheet storage devices having a middle plate that can be raised and lowered, and sheet feeding devices having a sheet feeding means and a lifting means. The apparatus is provided with a detection means for detecting that the uppermost surface of the sheets stacked on the sheet has been moved up by the lift means to the sheet feeding position, and the lift means for raising the intermediate plate is stopped in response to a signal from the detection means.

Then, when the top surface of the sheet lowers due to paper feeding,
When the intermediate plate is raised again by the lift means and the uppermost surface of the sheet is located at the paper feeding position, the lift means is stopped by a signal from the detection means.

(c) Problems to be Solved by the Invention Accordingly, the middle plate had to be raised every time several sheets were fed, and the operating noise at this time was frequently generated and was unpleasant to the ears. In particular, when the driving force for the lift means is obtained from another drive source, a drive transmission means such as a clutch is provided, and the driving force is transmitted to the lift means by turning on and off the clutch.
Since the clutch is turned on and off every time the intermediate plate is cut, raised and stopped, and several sheets are fed, the clutch has a short lifespan.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a sheet feeding device that can feed sheets within a predetermined range, thereby solving the above-mentioned problems.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, see, for example, FIGS. 1(a), (b), (c), FIGS. 2 and 3. , a sheet storage device (
52) and the sheet (S) from the sheet storage device (52).
a sheet feeding means (57) for feeding the intermediate plate (56);
) Lifting means (84) for urging the sheets stacked thereon towards the sheet feeding means (57)! In (51), the sheet feeding means (57)
is configured to be able to support the sheet (S) in a vertically movable manner and to feed the sheet (S) within a predetermined range in the vertical direction, and the sheet feeding means (57) is located within the sheet feeding range. A detection means (109) for detecting is provided, and when the detection means (109) detects that the sheet feeding means (57) is below the sheet feeding range, the lifting means (84)
to raise the intermediate plate (56) and transport the sheet feeding means (5
7) is characterized in that it is configured to be pushed up into the sheet feeding range.

(Phantom effect) Based on the above configuration, when the detection means (109) detects that the sheet feeding means (57) is below the sheet feeding range, the intermediate plate (56) is raised by the lifting means (84). The sheet feeding means (57) is then pushed up into the sheet feeding range by the sheets (S) stacked on the intermediate plate (56).

Note that the above-mentioned numbers in parentheses are shown for reference and are not intended to limit equivalent configurations.Examples Hereinafter, examples embodying the present invention will be described along with the drawings.

The optional feeder 51 as a sheet feeding device is
As shown in FIG. 2, it is mounted on a stand 2 provided at the bottom of the body 3 of the copying machine 1. Then, the copying machine 1 is
Detachably mounted cassettes 5, 6 are disposed within the machine body 3, and these cassettes 5, 6 can be pulled out in a direction perpendicular to the sheet conveyance direction. The fuselage 3 also has a pressure bonding plate 7. Platen9. Light source 10. It is equipped with mirrors 11, 12, 13, 15, 16, 17 and a lens 19. Furthermore, a paper feed roller 19 is attached to the cassette 5, and a paper feed roller 20 is attached to the cassette 6. A separation section 21 consisting of a separation roller and a conveyance roller is provided downstream of the roller 19, and a similar separation section 22 is provided downstream of the roller 20. Further, a paper feed path 23 is provided on the downstream side of these separating sections 21 and 22, and a pair of conveying rollers 25 is disposed on the path 23. Furthermore, a pair of registration rollers 26 is disposed on the downstream side of the path 23, and a copying section 27 is disposed downstream of the pair of rollers 26. A transport section 29 is provided downstream of the copying section 27, and a fixing device 30 is provided downstream of the transport section 29. Further, a conveying roller 31 is disposed downstream of the fixing device 30, a flapper 32 is disposed downstream of the roller 31, and a pair of paper ejection rollers 33 is disposed downstream of the flapper 32. is installed. On the other hand, a re-conveying path 35 is provided branching off from the flapper 32, and a pair of conveying rollers 36, 37, 39 and a pair of re-feeding rollers 40 are disposed on this path 35. In addition, the aircraft 3
A manual feed tray 41 is provided protruding from the right side of the paper, and a paper feed roller 42 is provided at the base end of the tray 41. Further, on the downstream side of the roller 42, a separation section 43 consisting of a separation roller and a conveyance roller is provided, and on the downstream side of the separation section 43, a
A manual feed path 45 is provided. Further, a hole 46 is bored in the lower part of the body 3, and a conveyance path 49 communicating with the paper feed path 23 is provided on the back side of the chain hole 46. A conveying roller pair 50 is provided. Further, the optional feeder 51 is configured to hold the sheet S.
It consists of a vapor deck 52 that stores the sheets S, and a unitized sheet feeding section 53 that feeds the sheets S from the deck 52.The deck 52 is placed on a guide rail 55 and can be pulled out toward the front. There is. The deck 52 has a middle plate 56 on which the sheets S are loaded, and the middle plate 56 is raised and lowered by a lift device to be described later. Further, the paper feeding section 53 has a pickup roller 57 that feeds the sheet S, and on the downstream side of the roller 57, a separation section 59 consisting of a separation roller 59b and a conveyance roller 59a is arranged. . Further, a paper feed path 60 is provided downstream of the separation section 59, and when the machine body 3 is mounted on the stand 2, the path 60 is connected to the conveyance path 49 opposite to the hole 46. It's like it's connected.

As shown in FIGS. 3 and 4, the front plate 61 and the f&side plate 62 of the vapor deck 52 have shafts 63.6.
A sprocket 66 is fixed to the front side of the shaft 63, and a sprocket 67 is fixed to the rear side of the shaft 63. Further, a sprocket 69 is fixed to the front side of the shaft 65, and a sprocket 7 is fixed to the rear side.
0 and an input gear 71 are fixed, a chain 72 is stretched between the front sprockets 66 and 69, and a chain 73 is stretched between the rear sprockets 67 and 70. Further, a guide rail 7 is provided on the front side plate 61.
A guide rail 77 is provided on the rear side plate 62, and a long hole 79 is formed in the rear side plate 62. A guide 80 is provided on the front side of the middle plate 56 and is fitted onto the guide rail 75 through the elongated hole 76, and a similar guide 81 is provided on the back side. Further, the cut-and-raised portion 80' of the guide 80 is fixed to the chain 72 with a screw 82, and the cut-and-raised portion 81' of the guide 81 is also fixed with a screw 82.
3 to the chain 73, thereby forming a lift device 84.

On the other hand, the paper feed section 53 has a rear plate 85, as shown in FIGS. 5 and 6, and the rear plate 85 has a hole 85a and a hole 85b into which the input gear 71 is inserted. It is perforated. And applicable? A microswitch 86 is disposed facing 1.85b, and the switch 86 is turned on and off by means of a bottle 87 protruding from the rear plate 62 of the vapor deck 56. Further, a drive motor 89 is provided on the rear side plate 85, and a gear 90 is fixed to an output shaft 89a of the motor 89.

Further, gears 91 and 92 mesh with the gear 90, the gear 92 is connected to an input shaft of a clutch 93, and a gear 95 is connected to an output shaft 93a of the clutch 93. The gear 95 meshes with the gear 96,
A one-way clutch 99 is provided between the gear 96 and the shaft 97.
is installed. Further, the gear 91 is the clutch 10
0, and a pulley 102 and the conveyance roller 59a are fixed to the output shaft 101 of the clutch 100. Furthermore, the support plate 103 is supported by the shaft 101.
is rotatably supported, and a shaft 1 is mounted on the support plate 103.
05 is rotatably supported. Then, the shaft 105
A pulley 106 is fixed in opposition to the pulley 102, and a timing belt 107 is stretched between the pulleys 102 and 106. Further, the pickup roller 57 is fixed to both ends of the shaft 1o5. Furthermore, a separation roller 59b is fixed to the output shaft 89a of the motor 89, and is pressed into contact with the conveyance roller 59a.

Then, the support plate 103 is mounted as shown in FIGS.
As shown in e), a portion 103a extends upward, and a seat height sensor 109 that is turned on and off by the negative portion 103a is disposed facing the portion 103a. Further, when the intermediate plate 56 is lowered by the lift device 84 and the sheet S is separated from the pickup roller 57, the roller 57 rotates counterclockwise due to its own weight and comes into contact with a stopper (not shown) to a predetermined position A. Further, the sheets S loaded on the intermediate plate 56 lifted by the lift device 84 come into contact with the pickup roller 57 and push up the roller 57. , the position where the tip of the part 103a of the support plate 103 turns on the sheet height sensor 109 is defined as the paper feed lower limit position B.

Next, the operation of this embodiment will be explained with reference to the flowcharts of FIGS. 7 and 8.

When the paper deck 52 is pulled out, the input gear 71 is not engaged with the gear 96, and the middle plate 56 has descended to the lowest position due to its own weight and the weight of the sheets S to be loaded. At this time, the pickup roller 57 is rotated to a predetermined position A due to its own weight (see FIG. 1(a)).

Then, the operator replenishes the sheet S onto the middle plate 56,
When the vapor deck 52 is inserted into the paper feed position (31),
When the input gear 71 and the gear 96 engage, the bottle 87 turns on the micro switch 86 to detect that the de-tsuki 52 is at the paper feeding position (S2), and then,
The motor 89 is started by the signal from the switch 86, and the clutch 93 is turned on (33).
The driving force from is transmitted to input gear 71 via gears 90, 92, and 96. Further, the clockwise rotation of the gear 71 causes the sprockets 69, 70 to rotate clockwise, and the clockwise rotation of these sprockets 69, 70 causes the chains 73, 75 to also rotate clockwise, and the middle plate 56 rises together with these chains 73, 75. Then, the uppermost sheet S loaded on the intermediate plate 56 comes into contact with the pickup roller 57 and pushes up the roller 57, and the part 103a of the support plate 103
09 is turned on (S4). Note that the position where the part 103a of the support plate 103 contacts the sensor 109 is the paper feed lower limit position B (see FIG. 1(b)). 56 was further raised,
After the sensor 109 is ONL, a predetermined time a(secl
lapses (S5), the clutch 93 is turned off and the motor 89 is stopped to complete the lifting of the middle plate 56 (38). At this time, the position where the uppermost sheet S is located is the paper feeding upper limit position C. , and the rising speed of the middle plate 56 is y (u
rn/sec), the uppermost sheet S is located av (mml) above the paper feed lower limit position B (Fig. 1(e)
)), in this case, the middle plate 56 is under its own weight and the sheet S
However, the input gear 71 and gear 96 are engaged with each other, and the one-way clutch 99 in the gear 96 causes the input gear 71 to maintain its position without rotating. Paper feeding becomes possible.

Then, when the operator turns on the start key (37
), the motor 89 is started, and the clutch 100 is turned on at a predetermined timing for a predetermined time, and the driving force from the motor 89 is applied to the gears 90, 91 and the timing belt 10.
7 to the pickup roller 57. Then, the sheet S is fed to the separating section 59 by the pickup roller 57, and the conveying roller 5 rotates counterclockwise.
9a and separation roller 59b, the sheets are separated one by one and conveyed (S8). Furthermore, the sheet S is fed through the paper feed path 57.
The paper is transported from the paper through the transport path 49 to the paper feed path 23, and
The image is conveyed by a pair of conveyor rollers 25 to a pair of registration rollers 26 , and is conveyed by the pair of rollers 26 in synchronization with the image on the copying section 27 . Then, the image is copied on the sheet S by the copying section 27, and the sheet S is conveyed to the fixing device 30 by the conveying section 29. Then, the image is fixed on the sheet S by the fixing device 30, and the sheet S is conveyed to the flapper 32 by the conveyance roller 31. Further, the sheet S is guided by the flapper 32 to a pair of paper discharge rollers 33, and is discharged from the machine body 3 by the pair of rollers 33.

By the same operation, the sheets S are sequentially fed and the sheets S
Even if the stacking height of the paper falls, the pickup roller 57 gradually lowers and paper feeding continues. Thereafter, when the pickup roller 57 descends to the lower limit position after paper feeding progresses, the part 103a of the support plate 103 is separated from the sheet height sensor 109, and the sensor 109 is turned off (S9
), and if the thickness of the sheet S is b [mml], then av/b sheets S can be fed from the upper paper feeding position XC to the lower limit value WB. And seat height sensor 10
9 is turned off, the signal from the sensor 109 causes a
(Clutch 93 is ON only during seeJ (S10)
The middle plate 56 is raised by av (am) by the same operation as described above. Then, when a(see) has passed (81
1), the clutch 93 is turned off and the lifting of the middle plate 56 is finished (S12), and the desired set number of sheets S is
The operations from S8 onward are performed until the copying of the desired set number of sheets is completed (S13), and the motor 89 is stopped and the clutch 93 is turned off (3).
14), the copying operation ends (S15).

Then, when the copying operation is repeated by the same operation and there is no more sheet S on the vapor deck 52, a signal from a sheet presence/absence sensor (not shown) is used to display the fact that there is no sheet on the operating section. Then, the operator confirming the display pulls out the vapor deck 52 toward the front, and then,
The input gear 71 is separated from the gear 97, the middle plate 56 is lowered to the lowest position by its own weight, and after replenishing the sheets S onto the middle plate 56, the operations after S1 described above are performed.

Note that in the above embodiment, the seat height sensor 109
Detects the paper feed lower limit position B, and from the position B a [s
Although the middle plate 56 is stopped from rising after [ec], the present invention is not limited to this, and as shown in FIG. 9, a sensor 110 for detecting the paper feeding upper limit position may be provided.

(G) As described in detail, according to the present invention, the sheet feeding device is configured to be able to feed sheets within a predetermined range, so the number of times the middle plate is raised and lowered is reduced, and the operation noise is reduced. and can also extend the life of the clutch.

[Brief explanation of the drawing]

FIGS. 1(a), 1(b), and 1(c) are front views showing essential parts of a sheet feeding device according to the present invention. Further, FIG. 2 is a front sectional view showing an image forming apparatus equipped with the present invention. Further, FIG. 3 is a front view showing essential parts of the sheet feeding device according to the present invention, and FIG. 4 is a plan view thereof. FIG. 5 is a rear view showing the main parts of the sheet feeding device according to the present invention, and FIG. 6 is a side view thereof. Further, FIGS. 7 and 8 are flow charts showing the operation of the present invention. Furthermore, FIG. 9 is a front view showing another embodiment of the present invention. FIG. 1(a) 51... Sheet feeding device 52... Sheet storage device W 58... Middle plate 57...
... Sheet feeding means, 84 ... Lifting means, 109
．． 110...Detection means S...Sheet.

Claims (1)

[Claims] 1. A sheet storage device having a middle plate that can be raised and lowered to load a large number of sheets, a sheet feeding means for feeding sheets from the sheet storage device, and a sheet storage device loaded on the middle plate. A sheet feeding device comprising: a lift means for biasing a sheet toward the sheet feeding means, wherein the sheet feeding means is supported so as to be movable up and down, and the sheet is fed within a predetermined range in the vertical direction. and detecting means for detecting that the sheet feeding means is located within the sheet feeding range, and detecting means for detecting that the sheet feeding means is below the sheet feeding range. The sheet feeding device is characterized in that the lifting device is configured to lift the intermediate plate and push the sheet feeding device up into a sheet feeding range when the lifting device detects the above.