JPH0445419B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a paper feed cassette for supplying paper to a printing device such as a printer, and its paper handling mechanism, and more specifically relates to a paper feed cassette for supplying paper to a printing device such as a printer, and its paper handling mechanism. The present invention relates to a paper sorting mechanism of this type that separates and supplies a stack of irregularly shaped sheets one by one.

[Prior Art] A general paper handling mechanism in a conventional paper feed cassette is a paper-separating mechanism that operates at the tips of both side guide plates of the cassette (the outline of which is the same as the both side guide plates of the cassette in the illustrated embodiment of the present invention). This was due to the weir plate installed at the top. In this mechanism, the upper edge of the weir plate prevents the advance of the paper at the leading edge of the uppermost paper, and when the paper feed roller attempts to feed the uppermost paper, first the paper itself The tip is supported by the upper edge of the weir plate and bends upward in an arched manner. When the paper subsequently flexes to a certain extent, the leading edge of the paper is unsupported by the upper edge of the weir plate, and the paper is repelled by its own stored spring force, so as to jump over the weir plate. At this time, the topmost sheet of paper and the sheets below it were separated and separated, that is, the sheets were separated by utilizing the flexure of the sheet itself and the accompanying spring action. . However, when feeding thick paper, for example, the paper cannot be sufficiently bent by the feeding force of the paper feed roller, so this mechanism cannot separate the paper.

Therefore, a paper separation mechanism for cardboard using a flexible pad in place of the dam plate has been proposed. In this mechanism, the upper edge of the flexible pad is placed approximately aligned with the surface of the topmost paper, and when the paper feed roller feeds the topmost paper, the tip of this pad is pushed against the paper. Although it deforms, the deformation resistance of the pad allows only the top sheet to pass through and prevents sheets below it from following. However, with this mechanism, it is necessary to adjust the position of the upper edge of the pad according to the thickness and type of paper, and in particular, the flap part for sealing like an envelope is the same thickness as a sheet of paper, and the glue margin is folded and attached to each other. The side edges of the pasted envelope are two or three sheets thick, making it difficult to handle irregularly shaped sheets that include Western and Japanese sizes, and in some cases double feeding may occur. A situation in which paper is not fed at all tends to occur, and a reliable and sufficient paper sorting effect cannot be obtained.

[Problems to be Solved by the Invention] The present invention has been made based on this viewpoint, and it solves the drawbacks of the above-mentioned prior art and can be applied to a relatively wide range of paper thicknesses, types, etc., especially the envelopes mentioned above. It is an object of the present invention to provide a paper sorting mechanism that is most suitable for separating and supplying irregularly shaped paper bundles one by one.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, each of the guide plates on both sides of the paper feed cassette has a guide plate that protrudes generally horizontally above the leading edge guide surface of the paper, and has a smooth lower surface to prevent the stack of paper. An overhanging plate that comes into contact with the upper surface of both edges of the paper and guides the uppermost paper is pivotally supported, and the tip of this overhang plate is extended in the paper feeding direction from the leading edge guide surface of the paper, and this extending portion is A friction plate was brought into elastic contact with the lower surface by a spring bias B, and the paper was expanded to pass through it.

[Function] To explain the function of sorting thick sheets, especially irregularly shaped sheets such as the above-mentioned envelopes, in a device configured as described above, the paper feed cassette according to the present invention is capable of handling a bundle of envelopes or thick paper sheets. When the paper feed tray is installed in the paper feeder with the side edges regulated by the guide plates on both sides, the paper feed tray moves the front part of the stack of envelopes or cardboard paper on the tray up and down along the leading edge guide surface until it reaches the top. A certain bundle of envelopes or cardboard paper is brought into contact with a paper feed roller in a paper feed device in a biased state. At this time, the upper surfaces of both edges of the leading edge of the envelope bundle or the cardboard sheet come into contact with the lower surfaces of the overhanging plates provided on the both side guide plates. As in the case of envelopes, the flap part is made of one sheet of thick paper, and the side edges of the envelope part have the thickness of two or three sheets of paper, and because of the irregular shape, the top surface of the envelope is the paper feed roller. Even if there is a difference in level between the two edges of the envelope with respect to the contact surface thereof, the overhanging plate can be reliably brought into contact with the upper surface of the envelope because it is separately pivotally supported by each of the guide plates on both sides.

When the paper feed roller feeds the top paper, the paper moves forward guided by the smooth underside of the outrigger. In the paper feeding direction of the overhang plate, a friction plate provided at the tip of a spring-biased lever is in elastic contact with the lower surface of the overhang plate, but the paper cannot pass by expanding this lever. can. That is, the top paper is
The thrust caused by the frictional force between the feeding surface of the paper feed roller and the paper and the stiffness of the paper overcome the stopping force caused by the frictional resistance of the friction plate and the paper passes through, but the paper is pressed against the paper by a spring-biased lever. The friction plate expands flexibly in response to changes in thickness, so it is irregularly shaped like an envelope and has a thickness of 1, 2, or 3 sheets depending on the flap and side edges of the envelope. Even if the number of sheets is exceeded, it is possible to pass through this gap without making any external adjustments.

On the other hand, in the paper handling mechanism of the paper feed cassette according to the present invention, even if the leading edge of the next or lower paper that moves along with the top paper is guided to the friction plate, the friction coefficient between the paper sheets is lower than the friction plate. Since the coefficient of friction is much larger, the next sheet of paper is prevented from advancing by the friction plate.

With the above configuration, in the paper handling mechanism of the present invention, the friction plate has spring elasticity that allows it to flexibly cope with the case where the uppermost sheet of paper has a partially different thickness, such as in an envelope. However, due to the difference in frictional resistance, sheets below the top are blocked and do not follow the top sheet. In this way, even irregularly shaped sheets such as envelopes can be reliably handled between the overhanging plate and the friction plate.

[Embodiment] Fig. 1 is a perspective view showing an embodiment of a cassette equipped with a paper handling mechanism according to the present invention, and this cassette is used for supplying both special paper such as envelopes and ordinary paper. Designed. 1 in the diagram
0 indicates the case housing, and the paper feed tray 1 is located on the front bottom of this case.
2 is provided. The paper feed tray 12 is movable up and down about a shaft 11 at the center of the housing 10, and is lifted up by a spring mechanism within the device when the main cassette is loaded into the paper feed device. Also, inside the cassette are a rear guide plate 14 and both side guide plates 16,1.
6, which can be moved and adjusted to align with the periphery of the paper depending on the length and width of the paper. Furthermore, two ribs 18 are provided on the front wall 17 of the cassette, and these ribs serve as guide surfaces 2 for the leading edge of the paper.
0 (in this specification, this means not only the existential surface but also the entire geometric locus along which the leading edge of the paper moves).

As shown in FIGS. 2 and 3, metal fittings 22 and 2 are provided at the tips of the side guide plates 16 and 16, respectively.
2 is supported so as to be swingable within a certain range around a shaft 21. The reason why the metal fittings 22, 22 are pivoted is that the position of the top of the paper changes depending on the diameter of the paper feed roller in the paper feed device, which will be described later. It is possible to have a wide range of Furthermore, it is possible to cope with differences in level that occur when using irregularly shaped paper such as envelopes.

The upper plate of the metal fittings 22, 22 is the guide plate 16, 1 on both sides.
It is formed as an overhang plate 24 extending forward of 6,
More specifically, the overhanging plate 24 is located above the leading edge guide surface 20, has a generally horizontal surface that supports the leading edge of the paper stack from above, and has a generally horizontal surface that supports the leading edge of the sheet stack from above. It extends in the direction of the wall 17. Further, a lever 26 is swingably supported on the side walls of the metal fittings 22, 22, and this lever 26 is attached to the metal fittings 22, 22.
It is urged upward by a spring 25 hung between the side walls 2 and 22. Further, the tip of the lever 26 is bent inward at a position beyond the tip guide surface 20, and a support plate 27 extending diagonally upward is formed on the top of the tip. A friction plate 28 is fixed to the upper surface of the support plate 27, and the friction plate 28 is pressed against the lower surface of the overhanging plate 24 at a position forward of the upper end position of the tip guide surface 20 in the paper feeding direction. Face contact in biased state. Further, a leading edge guide plate 29 provided on the paper side of the support plate 27 adjacent to the friction plate 28 is a plate having a smooth surface for guiding the leading edge of the paper to the friction plate, and is inclined at the front edge of the lever 26. It is fixed in the shape.

Next, a description will be given of the paper feeding operation when stacking a bundle of envelopes in the paper feeding cassette having the above configuration and feeding the paper into the printer main body.

The envelope has an enclosing section made by folding the glue margins and pasting them together, and a flap section for sealing. The flap part is the thickness of one sheet of paper, but there are two
There are paper thicknesses of 3 to 3 sheets. The front surface of the envelope is a smooth surface printed by a printer, and the back surface has a step formed with a glue margin.

Here, the envelopes are stacked in the paper feed cassette with their backs facing upward and their flat portions facing the paper feed direction. When the paper feed cassette is loaded into the paper feed device, the paper feed table 12 rises and the stack of envelopes is placed on the leading edge guide surface 2.
0, and the uppermost envelope is brought into elastic contact with the paper feed roller 5 in the paper feed device.

When paper feeding starts, the topmost envelope is pressed against the friction plate 2.
However, under certain conditions, the flaps of multiple envelopes below the topmost layer are guided to the friction plate 2.
There may be cases where you will be guided to 8. However, since the lower surface of the overhang plate 24 is smooth and the friction plate 28 has a friction surface, the difference in these friction coefficients is larger than the friction coefficient between envelopes, and the The upper envelope passes between the friction plate 28 and the overhanging plate 24, and the next envelope is blocked by the friction plate 28 and is not fed. Furthermore, the enclosing part of the envelope is covered with a friction plate 2.
8, the thickness of the envelope is 2 times the thickness of a sheet of paper.
It will be double or triple the amount, but the envelope being conveyed will have 2 springs.
The lever 26 is rotated counterclockwise against the biasing force 5, and the gap between the overhanging plate 24 and the friction plate 28 is widened in accordance with the paper thickness. Therefore, only the uppermost envelope is sorted and conveyed to the printer section. Further, since the back surface of the envelope with the step is fed upward, even if the step slides into contact with the lower surface of the overhang plate, the paper is fed without resistance. In this way, the sheets of paper are reliably separated one by one between the overhanging plate 24 and the friction plate 28, much like a person would slide two sheets of paper apart with his or her thumb and forefinger.

[Effects of the Invention] As described above, according to the paper sorting mechanism in the paper feed cassette according to the present invention, the following effects can be obtained.

a) By the cooperation of the overhanging plate with the friction plate, it is possible to adapt to a relatively wide range of conditions such as paper thickness and type, and reliably prevent double feeding, which was a particular drawback of the prior art. It becomes possible to solve the problem of paper handling for irregularly shaped paper such as envelopes.

b Since a paper sorting mechanism is provided on the cassette side,
There is no need to provide the same mechanism on the paper feeding device side.

c. The paper sorting mechanism of the present invention can be applied to conventional cassettes without changing their standards, so it can be easily used in various existing paper feeding devices.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a cassette equipped with a paper handling mechanism according to the present invention, and FIGS.
The figures are a plan view and a side view showing the main parts of the paper handling mechanism, respectively, and FIG. 4 is a perspective view showing the cassette shown in FIG. 1 loaded with paper into the paper feeder. 5... Paper feed roller, 10... Case housing, 12
... Paper feed tray, 14 ... Rear guide plate, 16 ... Side guide plate, 18 ... Rib, 20 ... Tip guide surface, 2
2...Metal fittings, 24...Extension plate, 26...Lever, 28...Friction plate, 29...Tip guide plate.

Claims (1)

[Scope of Claims] 1. A paper feeding cassette for feeding paper loaded into a paper feeding device, which cassette includes a paper feeding tray 12 and both side guide plates 16, 16, 1
2, when a cassette is loaded into the paper feeding device, the paper on the table is moved up and down along the leading edge guide surface 20 of the paper so as to come into contact with the paper feeding roller in the device in a biased state; Inner plates 16, 16 In a paper feed cassette that is movable so as to align with both side edges of the paper according to the paper width, each of the above-mentioned both side guide plates 16, 16 is provided with a plate above the leading edge guide surface 20 of the paper. An overhanging plate 24 that protrudes generally horizontally, has a smooth lower surface, abuts against the upper surfaces of both edges of the paper stack, and guides the uppermost sheet is pivotally supported, and the tip of this overhang plate 24 is connected to the leading edge guide surface 20 for the above-mentioned sheets. A lever 26 is provided which extends in the paper feeding direction, is pivotably supported below the overhang plate 24, and expands as the paper passes by a spring bias. A paper sorting mechanism in a paper feed cassette, characterized in that a friction plate 28 is brought into elastic contact with the lower surface of the extending portion.