JPH0318200Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention is applicable to a cylindrical scanning inkjet printer, a discharge recording device, an optical reader, etc., in which a sheet such as a recording sheet or a manuscript sheet is wound around a cylindrical drum. The present invention relates to a sheet winding device.

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

Figure 1 shows the main parts of the sheet supply structure applied to such an adsorption type sheet winding device by the applicant (Utility Application No. 10208/1982).
has a large number of through holes 2, 2 reaching from the surface to the inside.
3 is a sheet laminate stacked so that its starting end 3' faces the bottom of the drum 1, 4 is a replaceable sheet cassette on which the laminate 3 is placed, 5 is a A flexible charging sheet 6 provided on the stacked body mounting surface of the sheet cassette 4.
7 is a reinforcing plate provided at the starting end of the charged sheet 5 to prevent the starting end 3' of the sheet stack 3 from deflecting in the width direction; 7 is a push-up mechanism that comes into contact with the reinforcing plate 6 and pushes up the sheet stack 3; , the push-up mechanism 7 includes an electromagnetic solenoid 8, a plunger 9 that is retracted against the elasticity of a coil spring (not shown) due to the excitation of the solenoid 8, and a back-and-forth movement of the plunger 9 about a pivot point 10. It is comprised of a rotating lever 11 with a substantially L-shaped side surface that converts the rotating movement into a rotating movement, and a push-up roller 12 provided at one end of the lever 11.

Therefore, in the initial state shown in Figure 1,
When the electromagnetic solenoid 8 is energized while the inside of the cylindrical drum 1 is evacuated through the exhaust port 13 provided on the side surface and an adsorption force is formed in the through holes 2, 2..., the plunger 9 moves inside the solenoid 8. is attracted and causes the rotation lever 11 to rotate clockwise. As a result, the push-up roller 12 passes through the passage opening 14 opened at the bottom of the sheet cassette 4 and pushes the starting end 3' of the sheet stack 3 through the reinforcing plate 6 to the drum 1.
Push up toward the through hole 2. The starting end 3' of the sheet stack 3 that has been pushed up comes into contact with the through hole 2 of the drum 1 where the suction force is formed, or comes close to a distance where such suction force can act, and the starting end 3' of the sheet stack 3 Only the leading edge 3' of the upper sheet is held by the suction force. Once the starting end 3' is at the drum 1
When the sheet cassette 4 is attracted and held, the electromagnetic solenoid 8 is deenergized and the push-up roller 12 is moved toward the sheet cassette 4.
The uppermost sheet and the second and subsequent sheets are separated. Next, when the drum 1 is rotated once counterclockwise, the topmost sheet is successively attracted to the through holes 2, 2, . . . on the surface of the drum 1, and the winding of the sheet around the drum 1 is completed.

However, with such a configuration, if the thickness of the sheet stack 3 is thin as shown in FIG. 2, the starting end 3' can be attracted to the surface of the drum 1 and one sheet can be wound up without any problem. When the sheet stack 3 is thick like this, the starting end 3' of the sheet stack 3 has a weak adsorption force due to a combination of static electricity between the sheets or the sheets not being handled well, and the sheets' own weight or stiffness. It is impossible to get close to the surface of the drum 1 on which the surface of the drum 1 acts, and the sheet starting end 3' on the uppermost surface of the laminate 3 is inserted into the through holes 2, 2, . . . on the surface of the drum 1.
It cannot be held by adsorption. Therefore, the thickness of the sheet stack 3 had to be reduced, and the maximum number of sheets that could be held had to be reduced.

(c) Purpose of the invention The present invention has been made in view of the above points, and its purpose is to ensure sheet winding regardless of the thickness of the sheet laminate.

(d) Structure of the invention The push-up mechanism in the sheet winding device of the invention that pushes up the sheet stack toward the through hole of the cylindrical drum includes a rotating member whose at least one end rotates, and a rotating member that rotates at least one end. A plurality of push-up members are provided at the one end of the member and sequentially abut against the sheet stack in order to push up the starting end of the sheet stack in accordance with the thickness thereof.

(E) Embodiment Figures 4 to 7 show an embodiment of the present invention.
Components that are the same as before are given the same numbers and explanations are omitted. That is, the feature of the present invention is that the rotating lever 1 of the rotating member in the push-up mechanism 7 as shown in FIG.
1, there are provided first and second push-up rollers 15 and 16 that act as two push-up members. The first and second push-up rollers 15,
16 is attached in a stepped manner to opposing pieces 17 and 18 which are separated at one end of the rotary lever 11 and have stepped side surfaces.

Therefore, for a thin sheet stack 3 as shown in FIG.
The push-up roller 15 contacts the reinforcing plate 6 and pushes up the starting end 3' of the sheet stack 3. However, in the process of such a push-up operation, the push-up distance until suction is long, so the second push-up roller 16, which has a larger rotation radius than the first push-up roller 15, eventually takes over the push-up action. Then, the starting end 3' is pushed up to the area where the adsorption force acts. As a result, the starting end 3' is adsorbed and held in the through hole 2 on the surface of the drum 1.

On the other hand, for a thick sheet laminate 3 as shown in FIG. The starting end 3' of the sheet stack 3 is pushed up to the area of attraction formed in the through hole 2 of the drum 1 by the pushing up operation of the push up roller 15 alone. That is, the contact point of the first push-up roller 15 is a point slightly outside of the starting edge which is pushed up by a rotation smaller than that of the second roller, and the uppermost surface of the sheet stack 3 and the drum 1 are in contact with each other. Since the facing distance is reduced, the second push-up roller 16 does not act on such a thick laminate 3.

(f) Effects of the invention As is clear from the above explanation, in the present invention, the starting end of the sheet laminate is pushed up against the drum by a plurality of push-up members that sequentially contact the laminate in order to push it up in proportion to the thickness of the sheet laminate. As it is pushed up towards the through hole,
The sheet can be reliably wound around the drum regardless of its thickness, and the maximum number of sheets that can be held can be increased.

[Brief explanation of the drawing]

Figures 1 to 3 are cross-sectional views showing the conventional example according to its state, Figures 4 to 6 are cross-sectional views showing an embodiment of the present invention according to its state, and Figure 7 is a top view showing the main parts of the present invention. It is a diagram. DESCRIPTION OF SYMBOLS 1... Cylindrical drum, 2... Through hole, 3... Sheet laminate, 7... Push-up mechanism, 11... Rotating lever, 15, 16... First and second push-up rollers.

Claims (1)

[Scope of utility model registration request] By evacuating the inside of the cylindrical drum, a suction force is created in the through hole bored on the surface of the drum,
In a sheet winding device that uses the suction force to adsorb the starting edge of a sheet and wind the sheet on the surface of the drum, a sheet stack is placed at the bottom of the drum, and the starting edge of the stack is attached to the drum. a push-up mechanism that pushes up toward the through hole; the push-up mechanism includes a rotating member whose at least one end rotates;
A sheet characterized by comprising: a plurality of push-up members provided at the one end of the rotating member and sequentially abutting the sheet laminate in order to push up the starting end of the sheet laminate in accordance with its thickness. Winding device.