JPS5943742A - Sheet paper feeder - Google Patents

Abstract

PURPOSE:To make an accurate delivery of sheets performable, by having a sheet paper feeding device pressed on to a sheet surface in an elastic manner through a spring member when the feeding device contacts on the sheet surface, while preventing the device from bounding. CONSTITUTION:When a paper feed starting signal is given to a paper feeder, a driving roller 11 in a paper feed roller rocking unit 2 rotates, rotation of this roller 11 is transmitted to a driven roller 15 via a driving belt 4, a semicircular paper feed roller 13 attached to a shaft 14 of this roller 15 is turned round as far as a specified angle from its stand-by position, contacting on the surface of the topmost taper on a mounting table, and paper feeding operation is thus started. At this time, the paper feed roller 13 is given a paper feeding pressure by a spring member (plate spring) 5 supported by the said rocking unit 2, and with this paper feeding pressure, a large bound of the paper feed roller 13 in time of feeding operation is eliminated, thus accurate, stable paper feeding takes place.

Description

[Detailed Description of the Invention] The present invention applies to copying machines, printing machines, recording machines, and other sheets (including copying paper, transfer paper, printing paper, recording paper, and various glazed sheet-like materials that can hold fine images thereof). The present invention relates to sheet feeding devices for various machines (hereinafter referred to as copying machines, etc.) equipped with a conveying mechanism.

Conventionally, as a device for this purpose, for example, a paper feed table on which sheets are loaded is intermittently moved upward to a certain feeding position using a lifter or the like to maintain the topmost sheet position within a predetermined range, and then There are feeding methods that feed one sheet at a time, but strictly speaking, the top sheet position varies within a predetermined range (so a fixed type (non-vertical) feeding roller cannot feed sheets one by one). In some cases, a feed roller is normally used that can move up and down against the top sheet by its own weight or by an appropriate weight. , or in order to eliminate clutches, etc., a half-moon-shaped roller is often used as the feed roller, but the half-moon roller itself bounces due to contact/non-contact with the top surface of the sheet. During high-speed feeding, the bounce becomes thick (and the half-moon roller should be in contact with the sheet, but it becomes in a non-contact state, and as a result, the sheet cannot be fed a specified distance (and becomes). This had the disadvantage of causing poor sheet timing and the like.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel sheet feeding device that is improved in view of these drawbacks.

Another object of the present invention is to provide a sheet feeding device that can prevent sheet feeding means from bouncing and accurately feed the sheet.

That is, the main structure of the present invention to achieve the above object is a sheet feeding device that feeds sheets by repeatedly contacting and non-contacting the feeding means to improve the stacked sheets, and when the feeding means A sheet feeding device characterized in that the feeding means is provided with a spring member that elastically presses the feeding means against the sheet surface so that the feeding means does not separate from the sheet surface when it comes into contact with the sheet surface. be.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partial sectional view of a copying machine to which the present invention is applied.

In the figure, 1 is a paper feeding device that feeds sheets, 2 is a paper feed roller swing unit, 6 is a fixed shaft that supports the paper feed roller swing unit 2, 4 is a transmission belt that transmits drive to the paper feed roller, 5 6 is a spring member that is supported by the unit and applies paper feeding pressure to the paper feed roller; 6 is a part of the stem that serves as the fulcrum of the spring member 5;
Gui, 7-1 salary? 8 is a guide layer, 9 is a resistor rJ-ra, 10 is a photosensitive drum, and 11 is a stock horn member for regulating the movement of the paper roller swinging unit 2 and preventing the unit itself from coming into contact with the paper 12. A drive roller, 16 is a half-moon paper feed roller, 14 is a shaft of the paper feed roller 6 supported by the unit 2, 15 is a driven roller attached to the shaft 14, 16 is a roller that holds the paper 12 on the upper and lower wheels D, and 17 is a wire, 18 is a lifter driving device that lifts the platform 16 via the wire 7, 19 is an abutting part of the unit 2 that hits the stopper member 7 to determine the lower limit of the unit 1-2; 20 is an arrow showing how unit 2 swings;
Reference numeral 1 indicates the main body of the photographed apparatus.

FIG. 2 is a partial cross-sectional view showing the paper feed roller 3 at the standby position, that is, the post-feed position. This prevents the paper feed roller swing unit 2 from coming into contact with the paper. In this state, the paper gripped by the register rollers 9 is under almost no load, so that good paper feeding can be performed.

FIG. 6 is an enlarged perspective view of the paper feed roller swing unit 2. FIG.

In FIG. 1, the lifter driving device 18 is driven intermittently so that the uppermost paper surface on the table falls within the range 11.

Next, when a paper feeding start signal is applied to the paper feeding device, the paper feeding roller 15 begins to rotate υ from the standby position shown in FIG. 2, and then enters the state shown in FIG. 1 and starts feeding paper. At this time, the paper feed roller 13 swings according to the height of the minimum paper surface (varies within the range of h), and the paper feed pressure at that time is applied to the spring member 5, so there is no large bounce (stable feeding is achieved). Next, the fed paper is registered by the register roller 9, and is conveyed by the register roller 9 in synchronization with the photosensitive drum 10. At this time, the paper feed roller 13
As shown in the figure, the load on the paper separated from the top paper is almost zero.

Next, other embodiments will be described. FIGS. 4 and 5 show partial cross-sectional views thereof. In the embodiment shown in FIG. 4, a tension coil spring 51 is used in place of the spring member (plate spring) 5 of the previous embodiment. The one shown in FIG. 5 is one in which a hole 61 is provided in a fixed gourd member 6, one end of a leaf spring 5 is inserted into the person 61, and the stopper member 7 described above is used.

As explained above, according to the configuration of the present invention, the sheet feeding means elastically presses the sheet direction with an appropriate pressing force without leaving the sheet surface 2 when necessary, so that it can be used, for example, by half-moon rollers. Even when using contact or non-contact feeding means, extremely stable sheet feeding is possible.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a copying machine to which the present invention is applied, FIG. 2 is a partial sectional view showing the paper feed roller in a standby position, and FIG. 6 is an enlarged perspective view of the paper feed roller swing unit. , 4th
FIG. 5 is a partial sectional view showing another embodiment. In the figure, C12 is a paper feed p-ra swing unit, 5 is a paulownia spring (plate spring), 51 is a tension coil spring, 61 is a hole, 7 is a stopper member, and 16 is a half-moon paper feed roller. Applicant Canon Co., Ltd. No. 4 [Ra1 No. 5]

Claims (1)

[Scope of Claims] In a sheet feeding device that feeds sheets by repeatedly feeding the sheet by contacting or non-contacting the feeding means onto the surface of the stacked sheets, when the feeding means comes into contact with the surface of the sheet. A sheet feeding device characterized in that the feeding means is provided with a spring member that elastically presses the feeding means onto the sheet surface so that the feeding means does not separate from the sheet surface.