JP2618687B2 - Sheet feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a sheet feeding apparatus applied to a sheet feeding unit of, for example, a printer, a word processor, a copying machine, a printing machine, and the like.

(Prior Art) Conventionally, a device that automatically feeds a printing device in a typewriter, a printer, a word processor, or the like includes:
A sheet separation mechanism is provided for separating only one sheet from a large number of stacked sheets and sending the separated sheet to a printing apparatus. There are various methods for this separation mechanism, and a claw separation method is one of them.

FIG. 3 is an explanatory diagram for explaining a nail separation method.
In the figure, a stacked sheet 100 is pressed against a feed roller 102 and a separation claw 103 by a spring or the like via a pressure plate 101 or the like (see FIG. 3A). Here, when the feeding roller 102 rotates, the sheet 100 tries to advance in the feeding direction,
The corner of the sheet 100 cannot be advanced because it is interrupted by the stopper 104 of the separation claw 103, and a loop is formed between the separation claw 103 and the roller 102 (see FIG. 3B). When the loop reaches an appropriate amount, the sheet corners rebound over the separation claw 103 and are fed in the feeding direction, whereby the sheet 100 is separated (see FIG. 3 (c)). When the sheet is brought into contact with a feed roller (not shown) of the printing apparatus by the feed roller 102, the feed roller 102 is fed to a predetermined position by the feed roller to prepare for printing.

(Problems to be Solved by the Invention) However, in the above-described claw separation method, when a relatively rigid material such as a postcard is used, the feed roller 102 loses the "strain" of the sheet and runs idle. Since the loop cannot be formed, the separation claw 103 cannot be overcome.

For this reason, separate paper feeders dedicated to plain paper and postcards are provided, or an automatic paper feeder for plain paper is used with a postcard holder equipped with a postcard separation mechanism. Without this, automatic feeding of both plain paper and postcards could not be achieved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to automatically separate and feed one sheet at a time regardless of the rigidity of a sheet to be fed. An object of the present invention is to provide a sheet feeding device.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, the uppermost sheet of a stack of a large number of sheets is contacted and the uppermost sheet is fed. A feeding unit, a separation claw that engages with an upper surface of a leading end portion of the uppermost sheet, a stopper that abuts a leading end of the stacked sheet bundle in a forward direction in a feeding direction, and restricts movement of the sheet; A stopper releasing mechanism for releasing the sheet movement restriction by the stopper when the force in the feeding direction received from the sheet by the stopper by the contact exceeds a predetermined pressure, and is urged in the feeding direction by the feeding means. When the uppermost layer sheet is deformed by contacting the stopper and bends, the stopper is separated by a separation claw, and when an urging force of the predetermined pressure or more is applied to the stopper via the sheet, the stopper is stopped. The control mechanism works and the stopper In the sheet feeding apparatus configured so that the sheet is separated and fed after the restriction of the sheet is released, the stopper is provided so as to be slidable from the restriction position, and the surface of the stopper that comes into contact with the uppermost sheet is the corresponding contact. The stopper release mechanism is formed on an inclined tapered surface that deflects the pressing force received in the sliding direction, and moves the stopper to the regulating position so that the stopper moves when the depressed pressing force exceeds the predetermined value. It is characterized by comprising an elastic member that urges toward it.

(Operation) In the sheet feeding apparatus having the above configuration, in the case of a flexible sheet, when a feeding force is applied to the uppermost sheet by the feeding means, the leading end thereof is hindered by the stopper. Then, a loop is formed between the feeding means and the stopper, and when the loop amount becomes equal to or more than a predetermined value, the uppermost sheet is separated and fed one by one over the separation claw.

Next, in the case of a sheet having a high rigidity such as a postcard, if a feeding force is applied to the uppermost sheet by the feeding means, a loop is not formed due to the high rigidity, and the sheet is excessively moved to the stopper by the sheet front end. Pressing force acts. With this force, the stopper release mechanism operates to open the stopper, and one of the uppermost layers is separated and fed.

(Example) Hereinafter, the present invention will be described based on an illustrated example. 1 and 2 show a sheet feeding apparatus according to one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a strong "stiff" sheet (hereinafter referred to as "postcard") stacked in a large number, and reference numeral 1a denotes the top postcard of the outermost layer. The postcard 1 is supported by the pressure plate 2 from below, and the uppermost postcard 1a as the uppermost layer is brought into contact with a feeding roller 4 as a feeding means by a spring 3 that pushes up the pressure plate 2.

The feeding roller 4 feeds the postcard 1a in a predetermined direction, and the leading end of the postcard 1a in the feeding direction abuts on the stopper 6 to hinder the advance. On the other hand, a separation claw 5 is disposed at the front end corner of the postcard 1 in the feeding direction so as to engage thereon.

The stopper 6 is vertically movably supported by a support member 7 (a direction orthogonal to the sheet feeding direction), and the tip of the stopper 6 is connected to the separation claw 5 via a stopper spring 8 as an elastic member. Pressing.

When the force in the feeding direction from the sheet applied to the stopper 6 reaches a predetermined pressure or more, the stopper 6 moves downward against the spring force of the stopper spring 8 to open a gap between the separation claw 5 and the stopper 6. The stopper support member 7 and the stopper spring 8 constitute a stopper release mechanism.

The upper end of the stopper 6 has a tapered surface 6a so that when pressed by the postcard 1a, a component force acts in a direction in which the stopper 6 slides downward.

Further, the stopper spring 8 has a stronger force than a sheet having a weak "stiffness" enough to perform the conventional claw separation to push down the stopper 6, and a force weaker than a pushing-down force due to a sheet having a strong "stiffness" such as a postcard. Are adjusted so as to be pressed against the separation claw 5.

Next, the operation of the sheet feeding device having the above configuration will be described. The loaded postcard 1 is pressed against the feeding roller 4 and the separating claw 5 by the pressure plate 2 and the spring 3. When the feed roller 4 starts rotating in the feed direction (clockwise in the figure) according to the feed command, the uppermost postcard 1a is fed in the feed direction (left direction in the figure) due to friction with the feed roller 4. To hit the stopper 6.

At this time, the stopper 6 is pulled by the stopper spring 8 and pressed against the separation claw 5, so that the sheet path is closed.

When the sheet to be fed by the feed roller 4 is plain paper having a weak "strain", the stopper 6 is not pushed down and the sheet is sent over the claw in the same manner as in the conventional claw separation method ( (See FIG. 3).

However, when the sheet to be fed has a strong "stiffness" like a postcard, the stopper 6 is pushed down as shown in FIG. Go.

Here, even if the first postcard 1a is dragged by the top postcard 1a and the second and subsequent postcards 1 attempt to be multi-fed, the friction of the postcard 1 against the feed roller 4 and the postcard 1a is larger than the frictional force between the feed roller 4 and the postcard 1a. Is small,
Since the second and subsequent postcards 1 do not have a force to push down the stopper 6, only one sheet can be separated and fed.

Note that the present invention is not limited to the embodiment described above and shown in the drawings.For example, the support member of the separation claw and the stopper may be a separate component, or the stopper may be pushed up by a compression spring instead of a tension spring. It can be carried out with appropriate changes within a range not departing from the gist, such as good.

In the present invention, the uppermost postcard is adjusted by a stopper spring so that the second and subsequent sheets are not passed through in order to prevent double feed of postcards. If a means for restricting the amount of slide of the stopper is provided so that the amount of paper passes through but not more than two sheets, a more reliable separation system can be obtained.

(Effects of the Invention) As is clear from the above description, according to the present invention, a normal flexible sheet can be passed over the separation claw as in the conventional case, and a sheet having high rigidity can be released by the stopper release mechanism. The stopper opens to allow the passage of sheets, and a separation method that can separate sheets of different stiffness is obtained, so there is no need to prepare separate devices for plain paper and postcards as in the past. And the automatic feed of both becomes possible.

[Brief description of the drawings]

FIGS. 1 and 2 are main configuration diagrams showing an operation state of a sheet feeding device according to the present invention, and FIGS. 3 (a) to 3 (c) illustrate a claw separation system of a conventional sheet feeding device. FIG. DESCRIPTION OF SYMBOLS 1... Postcard (sheet), 4... Feed roller 5... Separation claw, 6.

Claims (1)

(57) [Claims] A feeding means for contacting an uppermost sheet of a multiplicity of stacked sheet bundles and feeding the uppermost sheet; and a separating means engaging with a top surface of a leading end of the uppermost layer sheet. A claw, a stopper for restricting the movement of the sheet by abutting the leading end in the feeding direction of the stacked sheet bundle, and a force in the feeding direction which the stopper receives from the sheet by the contact exceeds a predetermined pressure. And a stopper release mechanism for releasing the sheet movement restriction by the stopper. The sheet of the uppermost layer urged in the feeding direction by the feeding means is deformed by abutting on the stopper. If the urging force of the predetermined pressure or more is applied to the stopper via the sheet, the stopper releasing mechanism operates, the stopper is released, and the stopper is separated and fed. Configured sheet feeder In the above, the stopper is provided so as to be movable in a sliding direction from a regulating position, and a surface of the stopper that comes into contact with the uppermost sheet is formed as an inclined tapered surface that deflects a pressing force received by the contact in a sliding direction. Wherein the stopper releasing mechanism includes an elastic member that urges the stopper toward the regulating position so that the stopper moves when the deflected pressing force exceeds the predetermined value. apparatus.