JPH02193830A - Sheet feed device - Google Patents

Abstract

PURPOSE:To stabilize the rotation and stopping of a sheet feed roller and an eccentric cam, and improve the accuracy thereof at a stop position by providing a hook to be engaged with the notch of a notched cam at the position where the toothless part of a gear without a tooth partially is opposite to a drive gear, and engaging the toothed part of the gear with the drive gear upon the releasing of the hook. CONSTITUTION:When a solenoid 24 is turned on and a hook 23 engaged with the notch part 20a of a notched cam 20 is released, a gear 21 having no tooth partially begins to turn on the operation of a spring member 25 and the toothless part 21a of the gear 21 is dislocated from the opposite face of a drive gear 22, thereby causing the engagement of a toothed part with the drive gear 22. Consequently, a sheet feed roller 14 is supplied with a rotational force. A solenoid 24, after the engagement of the toothed part with the drive gear 22, is turned off and the hook 23 moves down due to the own weight thereof. When a sheet feed roller 14 rotates once, the hook 23 is properly engaged with the notch part 20a. In addition, the tooth-less part 21a of the gear 21 comes to be opposite to the drive gear 22 at the aforesaid engagement position and a geared state disappears, thereby causing the immediate stop of the sheet feed roller 14 and eccentric cam 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding device that applies paper feeding pressure only when feeding paper.

[Conventional technology]

Generally, the recording paper stacked on a paper feed tray is separated one by one and fed out, and the paper is fed through a conveyance path leading to a photoreceptor drum to a second paper feed roller, and the recording paper is brought into contact with a shutter at the second paper feed roller. In the case where the registration is aligned by using a paper feeding method, a paper feeding method is adopted in which paper feeding pressure is applied only during paper feeding. In this paper feeding method, a paper feeding tray is moved up and down by an eccentric cam, and when the paper feeding tray moves up, a paper feed roller is brought into contact with the recording paper on top of it, and the friction causes the paper to go over the paper presser pawl and is separated. Unlike paper feeding systems such as a sorting belt or roller, this system does not forcefully push the recording paper that has been placed against the shutter, and does not bend the recording paper.

In the case of this paper feeding method that applies paper feeding pressure only when feeding paper, the paper feed roller must be stopped after each rotation, so the shaft of the paper feed roller is connected to a continuously rotating drive gear that feeds the paper. For this purpose, a spring clutch has conventionally been used for such control.

[Problem to be solved by the invention]

However, in the spring clutch, the spring may not be tightened and rotation may not be imparted to the shaft of the paper feed roller.

Further, since the spring clutch is free to rotate in the opposite direction to the drive transmission direction, the drive may not synchronize with the roller shaft due to the rotational force applied to the cam due to the paper feeding pressure.

Therefore, it was not only difficult to maintain the stability of the rotation of the paper feed roller and the accuracy of the stop position of the cam that raises and lowers the paper feed pressure, but also required adjustment to achieve this accuracy.

This invention aims to solve the above-mentioned problems by improving the stability of rotation and stopping of the paper feed roller and eccentric cam, improving the accuracy of the stopping position, and providing a paper feeding device that does not require adjustment for achieving accuracy. The purpose is to capture and provide information.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a paper feeding device that applies paper feeding pressure only when the paper feeding pressure increases. A notch cam with notches at one location and a toothless gear having a toothless portion at one location are fixed, and the toothless portion of the toothless gear is engaged with the notch of the notch cam at a position facing the drive gear. It is provided with a locking hook and a spring member that biases the toothed portion of the partially toothed gear to rotate so as to mesh with the drive gear when the hook is removed. Therefore, for example, if the solenoid is turned on when the start button is pressed and the hook is removed from the notch of the notch cam, the partially toothed gear will rotate due to the action of the spring member, and the toothed portion of the partially toothed gear will rotate. It meshes with the drive gear and rotates a paper feed roller coaxial with the drive gear and an eccentric cam that moves the paper feed pressure up and down. When the paper feed roller rotates once and the hook engages with the notch of the notched cam, the toothless portion of the toothless gear faces the drive gear, and the mesh is lost, stopping the paper feed roller and eccentric cam at a predetermined position. It acts to cause

〔Example〕

Next, the present invention will be described based on an embodiment shown in the accompanying drawings.

1 and 2 are cross-sectional views showing the vertical movement of paper feeding pressure and the state of recording paper separation, FIG. 3 is a perspective view showing the drive means for the paper feed roller and eccentric cam, and FIG. 4(a). (b) is an explanatory diagram when the paper feed roller is at rest and when driving is started.

In the figure, 11 is a paper feed pressure whose base end 11a is hingedly connected to the lower edge of the side opening 10a of the copying machine main body 1o;
The tip end 1 lb of the paper feed pressure 11 is urged upward by a spring 12 whose lower end is fixed to the floor plate 10b of the main body 10 of the copying machine. 13 is an eccentric cam that moves the paper feeding pressure 11 up and down;
Reference numeral 14 denotes a paper feed roller that can apply paper feed pressure to the recording paper 15 when the paper feed pressure 11 moves upward (Fig. 2).
3 and the paper feed roller 14 are fixed to a common square shaft 16 so that they can rotate together. The paper feed roller 14 has a half-moon shape with a part of its circumference cut out, and is configured to make one rotation clockwise from a position where the circular portion 14a faces directly upward, as described later, and then stop. . At the base position of the paper feed roller 14, the eccentric cam 13 has its long diameter side 13a in sliding contact with a roller llc that is pivotally supported on the upper surface of one side edge of the paper feed pressure 11, and presses the paper feed pressure 11 against the spring 12. (See Figure 1).

The recording paper 15 stacked on the paper feed pressure 11 is supported at both ends on the leading edge side by the paper holding claw 17 by the weight of the claw.
Only one sheet of the uppermost layer to which paper feeding pressure is applied by the paper feeding roller 14 overcomes this, thereby preventing double feeding. Recording paper 15 carried out by climbing over this paper presser claw 17
a is supplied to the nipping point of the second paper feed roller 18.

The recording paper held between the second paper feed rollers 18 is conveyed through the paper feed path 19 to a third paper feed roller (not shown), where the recording paper is brought against a shutter and registration is performed. It looks like this.

In FIG. 3, 20 is a notch 20a at one location on the outer circumferential surface.
The notched cam 21 is a toothless gear having a toothless portion 21a at one location. The notched cam 20 and partially toothed gear 21 are fixed to a common square shaft 16 with the eccentric cam 13 and paper feed roller 14 so as to be able to rotate together.

Reference numeral 22 denotes a drive gear that drives the partially toothed gear 21. The drive gear 22 is connected to a drive source (not shown) and continuously rotates. 23, the toothless portion 21a of the toothless gear 21 is the drive gear 2.
The hook 23 is anchored to the notch 20a of the notch cam 20 in a state opposite to the notch cam 20, and the hook 23 is moored to the plunger 24a of the solenoid 24 so as to be able to rotate up and down about the hinge point 23a. . That is, solenoid 24
However, for example, by pressing the copy start button, etc.
When you press N and pull the plunger 24a, the hook 23 moves upward and comes off the notch 20a of the notch cam 20, and the solenoid 2
When 4 is turned off, it moves downward due to its own weight (or spring).

25, when the hook 23 is removed from the notch 20a of the notch cam 20 as shown in FIG. This is a spring member that engages with 22. The spring member 25 is stretched between the main body of the copying machine and the outer surface of the partially toothed gear 21 (so that it does not interfere with the rotation of the shaft 16).

In the above embodiment, when the copy start button is pressed to turn on the solenoid 24, and the hook 23 that is engaged with the notch 20a of the notch cam 20 as shown in FIG. 4(a) is removed as shown in FIG. 4(b). Due to the action of the spring member 25, the partially toothed gear 21
starts to rotate, and the toothless portion 21a is displaced from the opposing surface of the drive gear 22, causing the toothed portion to mesh with the drive gear 22. Therefore, this causes the paper feed roller 1 coaxial with the partially toothed gear 21 to
4 will be rotationally transmitted.

The solenoid 24 is driven just enough to remove the hook 23 from the notch 20a of the notch cam 20, and the partially toothed gear 2I rotates and engages its toothed portion with the drive gear 22, and then immediately turns OFF and removes the hook. 23 is moved downward by its own weight (or a spring) and is brought into sliding contact with the circumferential surface of the notched cam 20.

Therefore, when the paper feed roller 14 rotates once, the hook 23 is reliably engaged with the notch 20a of the notch cam 20. Moreover, at this locking position, the toothless portion 21a of the toothless gear 21 and the drive gear 22 face each other as described above and are not engaged with each other, so the paper feed roller 14 and the eccentric cam 13 immediately stop at that point. It happens.

[Effects of the Invention] As described above, in a paper feeding device that applies paper feeding pressure only when the paper feeding pressure moves upward, the present invention includes an eccentric cam that moves the paper feeding pressure up and down coaxially with the paper feeding roller; A notched cam with a notch provided at one location on the outer periphery and a partially toothed gear having a partially toothed portion at one location are fixed, and the notched cam has a notch at a position where the partially toothed portion of the partially toothed gear faces the drive gear. The paper feed roller and This provides various excellent effects, such as stabilizing the rotation and stopping of the eccentric cam, improving the accuracy of the stopping position, and eliminating the need for any adjustment to achieve accuracy.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, FIGS. 1 and 2 are cross-sectional views showing the vertical movement of the paper feed pressure and the state of separation of recording paper, and FIG. 3 shows the drive means for the paper feed roller and eccentric cam. Perspective view, 4th
Figures (a) and (b) are explanatory diagrams when the paper feed roller is at rest and when it starts to be driven. 10 - Copying machine main body 11 - Paper feed pressure 12 - Spring 13 - Eccentric cam 14 - Paper feed roller 15 - Recording paper 16 - Square shaft 17 - Paper presser claw 18 - First paper feed roller 19 - Feeding Paper path 20 - Notch cam 20a - Notch 21 - Missing tooth gear 21a - Missing tooth portion 22 - Drive gear 23 - Hook 24 - Solenoid 24a - Blunger 25 - Spring member

Claims (1)

[Claims] A paper feeding device that applies paper feeding pressure only when the paper feeding plate moves upward uses an eccentric cam that moves the paper feeding plate up and down coaxially with the paper feed roller, and a notched cam that has a notch at one location on the outer periphery. , a toothless gear having a toothless portion at one location is fixed, and a hook that engages with a notch of a notch cam at a position where the toothless portion of the toothless gear faces the drive gear, and the hook is removed. A paper feeding device comprising a spring member that rotates and urges a toothed portion of the partially toothed gear to mesh with a drive gear.