JPH0141704Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention involves winding a sheet such as a recording sheet or a manuscript sheet around a cylindrical drum of a cylindrical scanning type inkjet printer discharge recording device or optical reading device. The present invention relates to a sheet winding device.

(B) Prior art A method for winding a sheet around a cylindrical drum is disclosed in Japanese Patent Publication No. 54-15725, in which a number of air intake holes exposed on the surface and communicating with the inside are formed in the drum. There is a suction method in which a sheet is suctioned and wound using suction force (negative pressure) created by sucking outside air into the interior through an intake hole.

Such a winding device is required to be configured to reliably wind one sheet.

For this purpose, according to Japanese Patent Application Laid-Open No. 56-3239,
The idea is to provide a return roller that rotates in the opposite direction to the rotating drum that attracts the sheet, either in contact with it or with a small gap between it, and to prevent double feeding of the sheet through the action of this return roller. It is being

However, in this structure, if the rotating drum and the return roller are in close contact with each other,
There is a risk that even one sheet will not be able to pass through. On the other hand, if the minute gap is large, the effect of preventing double feeding cannot be achieved. Therefore, in this structure, the relationship between the rotating drum and the return roller must be precisely set in the design and assembly process.

In addition, when using sheets of various thicknesses, the distance between the rotating drum and the return roller is always constant, so if the sheet is thick, it cannot be fed at all, and on the other hand, if the sheet is thin, multiple sheets are fed. It happens that the sheet is fed.

Furthermore, the sheet stack is always maintained with a certain amount of clearance between it and the rotating drum, so in order to attract the topmost sheet, it is necessary to create a large adsorption force on the rotating drum. A large-scale device is required for the formation.
Furthermore, in this case, there is a risk that a plurality of sheets may be attracted to the rotating drum, which is contrary to the purpose of preventing double feeding of sheets.

On the other hand, a mechanism for taking out sheets one by one from a sheet stack using the adsorption force of a roller or a conveyor belt was disclosed in Japanese Patent Publication No. 39-118 and Japanese Utility Model Application No.
No. 55-176244.

Japanese Patent Publication No. 39-118 discloses that by using the adsorption force of a drum to which rotational driving force is supplied by a belt, one of the uppermost sheets is removed from a stack of sheets that is constantly urged in the direction of the drum. A sheet ejecting mechanism for ejecting sheets one by one is shown, and
In order to reliably take out one sheet, a beating member is provided which strikes the sheet attracted to the drum through a belt in a direction opposite to the direction in which the sheet is attracted. As a result, the sheet stuck under the sheet directly attracted to the drum is knocked off.

In addition, Japanese Utility Model Application Publication No. 55-176244 discloses a sheet feeding device that uses a conveying belt with suction power to take out the lowest sheets one by one from a stack of sheets placed on a conveying table and feed them. is listed. According to this device, by constantly pushing up the sheet stack, the sheets are separated and double feeding of the sheets is prevented.

However, according to the former configuration, since the structure is such that the sheet is struck in the opposite direction to the direction in which the sheet is attracted, in other words, in the direction in which the sheet is pulled away from the drum, it is possible to not only pull away the sheet that is clinging to the sheet to be attracted. , there is a fear that even the sheet to be suctioned may be separated from the roller or conveyed sheet, making it impossible to suction the sheet at all.

On the other hand, in the latter case, because the sheets are pushed up from below, even if the sheet directly above it is separated from the lowest sheet, the sheet immediately above it will fall back onto the lowest sheet, so the sheet It is not always possible to separate them well.

In the former case, the above-mentioned Japanese Patent Application Laid-Open No. 56-3239
As in the case of the above-mentioned publication, since the sheet stack is always maintained with a certain amount of clearance from the rotating drum, it has the above-mentioned problems.

(c) Purpose of the invention The purpose of the invention is to provide a sheet winding device equipped with a sheet feeding structure that can reliably feed sheets one by one from a sheet stack.

(d) Structure of the invention The present invention evacuates the inside of a cylindrical drum having an air intake hole exposed on the surface and communicating with the inside using an exhaust means, and winds a sheet by the adsorption force formed in the air intake hole. In the sheet winding device, there is a push-up mechanism that pushes up a stack of sheets disposed opposite to each other under the drum until the topmost sheet contacts the drum, and then lowers the stack, and a push-up mechanism that pushes up the sheet stack placed opposite to the bottom of the drum, and then lowers the sheet stack. This structure includes a hammer mechanism that strikes the laminate in the direction in which the sheets are attracted.

(e) Embodiment FIGS. 1 to 4 show an embodiment of the present invention according to its state, in which 1 is a cylindrical drum having a large number of intake holes 2 exposed on its surface and communicating with the inside; 3; An exhaust port is opened from one shaft of the cylindrical drum, and the exhaust port communicates with an exhaust means such as an exhaust motor (not shown) to exhaust the air inside the drum 1. Reference numeral 4 denotes a stack of sheets facing each other at an interval of about 10 to 30 mm below the drum 1, and 5 a replaceable cassette for placing and storing the stack of sheets. As shown in FIG. 5, a protrusion 6 is formed that is slightly shorter than the width of the opening, and when the sheet stack 4 is placed in the cassette 5, the starting end of the sheet stack 4 rests on the protrusion 6. Gaps 7, 7 are formed between the sheet stack 4 and the bottom surface of the cassette 5 on both sides of the starting end. 8 is a base having a cassette mounting surface 9;
0 and 10 are guide strips parallel to each other fixed to the cassette mounting surface 9, and the interval between these guide strips is approximately equal to the width of the cassette 5, so that the width of both side walls 5 of the cassette is approximately equal to the width of the cassette 5.
The cassette 5 can be inserted along the cassette mounting surface 9 with the cassettes a and 5b in sliding contact with the guide strips 10 and 10, respectively. Reference numerals 11 and 11 denote a pair of push-up guides that are fixed to the base 8 and extend in the insertion direction of the cassette 5, and each slope 1 provided at the tip of the guide
2 and 12 are opposed to the gaps 7 and 7 between the sheet stack 4 and the bottom surface of the cassette 5. Therefore, when the cassette 5 is inserted along the cassette mounting surface 9, the slopes 12, 12 relatively enter the gaps 7, 7, thereby pushing the sheet stack 4 toward the drum 1 (see FIG. 2). ). 13 is both guides 11,
11, this plate contacts the bottommost part of the sheet stack 4 pushed up by the push-up guides 11, 11, and both push-up guides 11, 1
This prevents the sheet 4 from sagging between the sheets 4 and 1.

Reference numeral 14 denotes a push-up mechanism, which includes a first plunger solenoid device 15, a first rotating lever 18 rotatably supported by a fulcrum 17, a first spring 19, and a push-up roller 20. Become. One end of the first rotating lever 18 is connected to the plunger 16 of the solenoid device and is biased upwardly by a first spring 19, and the other end is connected to a forked arm 18a, 1
8b, and a push-up roller 20 is rotatably supported parallel to the axis of the drum 1 between both arms 18a and 18b. Therefore, when the solenoid device 15 is driven against the biasing force of the spring 19, the first rotating lever 18 rotates, the push-up roller 20 moves upward, and the push-up roller 20 is moved by the push-up guide 11. Then, the starting end of the sheet stack 4 guided close to the drum 1 side is pressed against the drum 1 (FIG. 3).

Furthermore, 21 is a hammer mechanism arranged in a recess 9a provided in the cassette mounting surface 9 of the base, and this mechanism is connected to a second plunger solenoid device 22 and a fulcrum 24.
A second rotating lever 2 rotatably supported by
5, a second spring 26, and a roller 27. One end of the second rotary lever 25 is connected to the plunger 23 of the solenoid device and urged upward by a second spring 26, and a roller 27 is rotatably provided at the other end. Therefore, when the solenoid device 22 is driven against the biasing force of the spring 26, the second rotating lever 25 rotates, the roller 27 moves upward, and the cassette 5 passes through the hole 5 on the bottom surface of the cassette 5. Tap the bottom of the sheet stack 4 (FIG. 4).

When the cassette 5 containing the sheet stack 4 to be wound is inserted along the cassette mounting surface 9 of the base 8, the push-up guides 11, 11 move the starting end of the sheet stack 4 toward the drum 1 side. Push up to get close to. In this cassette state of cassette 5,
When the exhaust operation of the exhaust means is started, suction force is formed in the intake holes 2, 2, . The uppermost sheet starting edge of the drum 1 is pushed up so as to come into contact with the lower part of the drum 1. The starting end of the pushed-up sheet stack 4 deforms according to the surface shape of the drum 1, and comes into close contact with the drum surface so as to reliably close the intake holes 2, 2, . . . .

Here, an adsorption force is already formed on the surface of the drum 1, and the top sheet starting end of the sheet stack 4 comes into contact with the lower part of the drum 1 and is adsorbed to the drum 1 as described above. Then, when the drive of the first plunger solenoid 15 is released, the push-up roller 20
At the same time, the sheet stack 4a that is not attracted to the drum 1 descends. At this time, a plurality of sheets may be attracted and held on the drum 1 depending on the magnitude of the attraction force on the surface of the drum 1 or static electricity between the sheets. Therefore, next is the hammer mechanism 21.
When activated, the roller 27 provided at the other end of the second rotating lever 25 hits the bottom of the sheet stack 4 in the direction in which the sheet is attracted by the drum 1, causing an impact to the sheet stack 4. (Figure 4). Due to this impact, even if there are multiple sheets 4b held by the drum 1, the starting edge of the second and subsequent sheets, which have weaker adsorption force, will fall off, and only the starting edge of the first sheet will be adsorbed to the drum 1. Retained.

Finally, by rotating the drum 1 clockwise, the sheets are sequentially attracted from the starting end to the ending end, and the winding of one sheet onto the drum 1 is completed.

Note that the above-mentioned push-up operation, sheet suction, and hammer operation are controlled to be a series of operations.

(f) Effects of the invention The present invention has a configuration in which a stack of sheets placed opposite to each other at the bottom of a drum is pushed up toward the drum side by a push-up mechanism, and the sheets are struck by a hammer mechanism in the direction in which the sheets are attracted. By doing,
Since there is no need to provide a return roller that contacts the drum, it is possible to provide a sheet winding device equipped with a sheet feeding mechanism that can reliably feed one sheet without being affected by the thickness of the sheet.

In addition, we have provided a push-up mechanism that pushes up the stack of sheets placed opposite to each other at the bottom of the drum until the topmost sheet contacts the drum, and then lowers it. can be adsorbed.

Furthermore, when the sheets are separated by hitting them, the sheet is struck in the direction in which the sheets are attracted, so that the sheets that are being conveyed are not knocked off, and the sheets are not separated sufficiently. To provide a sheet winding device equipped with a sheet feeding mechanism capable of surely separating an undesired sheet clinging to a sheet to be fed from a sheet to be fed and feeding only one sheet without causing the sheet to be fed. be able to.

[Brief explanation of drawings]

1 to 4 show the state of one embodiment of the present invention, FIG. 1 is a plan view, FIGS. 2 to 4 are sectional views, and FIG. 5 is a plan view of the cassette 5. be. DESCRIPTION OF SYMBOLS 1... Drum, 2, 2... Intake hole, 4... Sheet laminate, 5... Cassette, 14... Push-up mechanism, 21... Hammer mechanism.

Claims (1)

[Scope of utility model registration request] In a sheet winding device for evacuating the inside of a cylindrical drum having an air intake hole exposed on the surface and communicating with the inside by an exhaust means, and winding the sheet by the suction force formed in the air intake hole, the drum a push-up mechanism that pushes up a stack of sheets placed opposite to each other at the bottom of the drum until the top sheet contacts the drum, and then lowers the stack of sheets; A sheet winding device characterized in that it is equipped with a hammer mechanism that hits the sheet in the direction of the sheet winding device.