JPH04260543A - Paper feed mechanism - Google Patents

Abstract

PURPOSE:To provide a paper feed mechanism for a printer, with Which a stable feed force may be exerted by a feed roller even though the width of sheets to be fed varies. CONSTITUTION:In a paper feed mechanism for a printer, if sheets 1 having a small width is fed, a plate 8 alone presses the sheets 1 against a feed roller 7 by means of a spring 9 so that the sheets does not reach a telescopic part 12. However, sheets 1 having a large size is fed, expandable parts bags 10, 11 in which incom-pressive liquid is charged press the sheets 1 against the feed roller 7 under action of levers 14, 15, in addition to the pressing by the plate 8 and the spring 9. Thus, the sheets having a large size can obtain a large feed force from the feed roller 7.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed mechanism for a printer that prints on a wide variety of cut sheets, and more particularly to a paper feed mechanism that can accommodate a variety of cut sheets.

0002

2. Description of the Related Art Conventional feeding mechanisms for various types of cut paper consist of a guide that stabilizes the running of the paper during paper feeding, claws at the left and right ends of the paper that apply a load when feeding the paper, a paper feed roller installed at the center of the device, and a paper feed roller installed at the center of the device. It consisted of a plate that pressed the cut paper against the paper feed roller.

[0003] Then, the feeding force of the paper feed roller is
When the frictional force between the paper being sent out and the remaining paper, the claws at the left and right ends of the paper, and the load on the paper became greater than the sum total, the paper was separated and sent out one by one.

0004

[Problems to be Solved by the Invention] In the paper feeding mechanism of such a conventional printer, in order to separate and feed sheets of paper width from small to large width one by one using one paper feeding mechanism, In order to feed a small width paper as stably as a large width paper, it is necessary to set the feeding force of the feed roller to be relatively weak. On the other hand, if a large sheet of paper is to be fed as stably as a small sheet of paper, the feeding force by the feed roller must be similarly strong.

[0005] In this way, in order to obtain a constant feeding force per unit paper width using the same paper feeding mechanism, it is difficult to always obtain stable paper feeding characteristics by following the variety of paper widths, as in the conventional example. If the contact width from which the feeding force is obtained is always fixed, there is a difficult problem in that it is almost technically impossible.

An object of the present invention is to provide a printer paper feeding mechanism that solves the above problems.

[0007]

[Means for Solving the Problems] The paper feeding mechanism of the present invention includes a side guide that stabilizes the running of paper during paper feeding, a claw rotatably fixed to the side guide, and a feed roller that feeds the paper. a plate for pressing the paper against the rollers; a bag made of a partially stretchable material and a non-expandable material; and means for filling the bag with an incompressible liquid.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the printer paper feeding mechanism of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an embodiment of the invention, and FIGS. 2 and 3 are cross-sectional views of the embodiment of FIG.

In FIGS. 1, 2, and 3, paper 1 to be stocked is guided in its position in the left and right direction by a right side guide 2 and a left side guide 3 during paper feeding and stocking. The right side guide 2 and the left side guide 3 have a pawl 4 and a pawl 5 which are rotatably supported at fulcrums 4' and 5', respectively. The right side guide 2 and the left side guide 3 can freely slide in the directions of arrows A and B in FIG. 1, respectively, with the paper feed frame 6 as a reference on guide rails a and b arranged in the left and right direction. It is located. As shown in the figure, the feed roller 7 is rotatably supported by the paper feed frame 6, and is rotated by a drive source and a controller (not shown).

The plate 8 faces the feed roller 7 and is pressed against the feed roller 7 by a spring 9. In addition, when the plate 8 is supplied with the stock paper 1,
It is released from the feed roller 7 by a lever (not shown).

The left and right bags 10 and 11 are fixed to paper feed frames 6, 6, and a stretchable material 12 is adhered only to the position facing the feed roller 7 without leaking. Moreover, the insides of the bags 10 and 11 are filled with an incompressible liquid 13, as shown in FIGS. 2 and 3. Then, left and right levers 14 and 1 facing the left and right bags 10 and 11, respectively, are provided.
5 is supported by the right side guide 2 and the left side guide 3.

Next, the operation of the paper feeding mechanism according to the embodiment of the present invention will be explained. When the width of the paper 1 is small as shown in FIG. 2, only the plate 8 presses the paper 1 from below against the feed roller 7 due to the spring 9, and the feed roller 7 is rotated by a drive source (not shown), and the paper 1 and the feed roller 7 are rotated by the drive source (not shown). The feeding force generated by the friction between the sheet 1 and the next sheet overcomes the sum of the frictional force between the sheet 1 to be sent and the next sheet and the load on the claws 4 and 5, and the sheet is separated and sent out. As shown in FIG. 2, when the width of the paper 1 is small, the paper 1 does not reach the stretchable section 12 and is not subjected to the pressing action from the stretchable section 12.

As shown in FIG. 3, when the width of the paper 1 increases, the spring 9 causes the plate 8 to add to the force pressing the paper 1 against the feed roller 7, and the left and right levers 1
4. The lever 15 presses the non-stretchable parts of the left and right bags 10 and 11 to reduce the internal volume. From this, bag 10,1
Since there is no place for the incompressible liquid 13 filled in the paper 1 to escape, the elastic material 12 is stretched and presses the paper 1 against the feed roller 7 with a predetermined force according to Pascal's principle. As a result, the frictional force between the feed roller 7 and the paper 1 becomes larger than when the width of the paper 1 is small, and the force for feeding the paper 1 increases.

[0014]

Effects of the Invention The printer paper feeding mechanism of the present invention includes a side guide that stabilizes the running of the paper during paper feeding, a claw that is rotatably supported by the side guide, a feed roller that feeds the paper, and a feed roller that feeds the paper. In addition to having a plate that presses against the feed roller, it also includes a bag that is partially made of stretchable material and the other part is non-stretchable, and is filled with a non-compressible liquid, so that it can be stabilized depending on the variety of paper widths. This has the effect of making it possible to feed paper in a controlled manner.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a printer paper feeding mechanism of the present invention.

FIG. 2 is a sectional view showing the operation of the embodiment of the present invention shown in FIG. 1 when the paper width is small.

3 is a sectional view showing the operation of the embodiment of the present invention shown in FIG. 1 when the paper width is large; FIG.

[Explanation of symbols]

1 Paper 2. Light side guide 3 Left side guide 4,5 Nails 7 Feed roller 8 Plate 10,11 bag 12 Elastic part 13 Incompressible liquid

Claims (1)

[Claims] 1. A paper feeding mechanism for a printer device that prints on various types of cut paper, including a side guide for stabilizing the running of the paper during feeding, a claw rotatably supported by the guide, and a claw for rotating the paper. It is characterized by comprising a feed roller that sends the paper out, a plate that presses the paper against the feed roller, a bag that is partially made of a stretchable material and the other part is made of a non-stretchable material, and an incompressible liquid filled in the bag. Printer paper feed mechanism.