GB2076786A - A Copy Paper Feeding Cassette - Google Patents

Abstract

In order to minimize the risk of a skew feed of paper from a cassette, resilient elements (24c) are provided on a pivotable reinforcing plate (24), which is pivoted to extend across a respective opening (21) in the cassette side wall (31), when the cassette is loaded in a copying machine. Each element (24c) may be slanted progressively inwardly of the cassette in the upward direction towards the open top thereof. Thus when the cassette is loaded, it is rigidified by the reinforcing plates, and the side edges of the uppermost sheets of a supply of paper in the cassette are brought into light pressurizing contact with the resilient elements to centralize the paper in the cassette. <IMAGE>

Description

SPECIFICATION A Copy Paper Feeding Cassette The present invention relates to a cassette to be used with an electrophotographic copying machine, a facsimile machine, printer, etc., (hereinafter referred to as "a copying machine"), and particularly to a copy paper feed cassette for preventing skew feeding of the paper.

Further, this invention relates to a cassette for storing many more sheets of copy paper, such as plain papers, therein as compared with a conventional cassette for the same items.

Hitherto in a copying maching, a cassette in which a number of copy papers, such as plain papers, are stored in advance is used to supply copy papers, and is loaded in a fixed position, and then the copy papers therefrom are fed one by one in accordance with a copying or printing operation. There are various sizes of copy papers according to the usage thereof and it is usual that each size of copy papers is stored in an exclusive cassette corresponding to the size and use. Either side of the cassettes is made a little larger in its inner dimension than the corresponding size of copy papers, therefore the copy papers can be piled irregularly in the cassette and get out of, or slip out of, the required position therein either a little to the right and the left or back and forth.

Also, a similar irregularity is caused due to the fact that the copy paper itself has a tolerance when being cut to the correct size and each copy paper can have an error in the measurement thereof within the allowable cutting tolerance. In synchronism with a copying or printing operation, the copy papers stored in a cassette are fed one by one by bringing feed rollers into pressurizing contact with the uppermost paper in the cassette, and in order to carry out a precise feed of the papers one by one, one previous method is to press lightly both corners of the front end of the uppermost paper by means of each element of claws called separation claws. However, the contact area of the separation claw and each front corner of the uppermost paper becomes uneven because the copy papers in the cassette are out of their correct position, which-causes skewing of the paper.There are normally a plurality of paper feed rollers in pressurizing contact with the uppermost paper for paper feeding, and because they do not contact with the paper the same pressure, the front end of the paper on the side thereof where there is greater contact pressure is transported faster and skewing of the paper occurs. Skew feeding of papers can cause an image slanting phenomenom which can then cause paper sticking, a so-called "jam", in the process up to the ejection of copied papers when the skewing of papers being fed becomes larger.

For the purpose of protecting copy papers from such skew feeding thereof, it has been proposed to use extruded pieces made of an elastic material such as sponge, etc., on the inner walls of the cassette, and arranged spaced from each other.

However, this has not corrected "out of position" in the transverse direction of the copy papers, because the extruded pieces are located at the same height in the direction of the thickness of the cassette and each of the pieces functions to the same degree over the height of a pile of stored copy papers. This arrangement can prevent broader papers among the papers stored in a cassette from skew feeding, but it has not been able to prevent narrower papers from skew feeding.

A similar problem occurs in a cassette which retains a large number of sheets of paper as described below.

In order to enhance business efficiency, high speed copying machines have recently been developed and used. Furthermore, such machines having a handling capability enhanced by high speed operation with the application of an electrophotography system as terminal equipment of a computer, are being put to practical use. For copying machines used for these purposes, cassettes capable of containing many sheets of copy paper are used. In such a cassette, many sheets of paper, e.g. 1000-2000 sheets, are loaded and a gate extending in the direction of the depth of the cassette is provided at a central position of each side wall of the cassette. An operator loads and unloads papers by holding the side edges of papers through this gate, otherwise it is not easy to load and unload papers therein.For such a large size of cassette as described above, the weight thereof when storing papers becomes considerably heavier and loading it into the main body of a copying machine is not very easy. Normally, the cassette is made monolithicly of formed plastics material having a sufficient strength to be durable enough to use.

Nevertheless when storing papers the weight of it becomes reasonably heavier, and consequently the cassette itself may become twisted when it is loaded in a main body of a copying machine.

Twisting of a cassette can cause distortion or sliding of papers stored therein, and affects a subsequent paper feeding action e.g. causing skew feeding of the papers.

The present invention has an advantage that it makes it possible, taking into consideration the above points, to provide a cassette capable of eliminating "out of position" of the uppermost sheets of the piled papers, or, to correct immediately skew feeding of papers by the aid of a correcting force, when such skew feeding is caused by an uneven contacting force applied to the papers by a plurality of paper rollers.

According to the present invention, there is provided a paper feed cassette to be used in a copying machine, for storing a plurality of papers and having a box-like configuration with a base plate, side walls, a front wall and a rear wall, the cassette comprising gate means formed in its side walls, respectively, a reinforcement member mounted on each side wall, respectively, so as to be capable of pivotting to a position across a respective gate means each reinforcement member having an elastic member arranged thereon to extend inwardly of the cassette, when the reinforcing member is positioned across its gate means, thereby to be in light pressure contact with the side edges of the uppermost sheets of papers stored, in use, in the cassette, the reinforcing member having a length more than the width of the respective gate means.

In accordance with the present invention, misalignment in the transverse direction of copy paper in a cassette, or, that which is caused by paper feed rollers during paper feeding, can be corrected by the elastic force of the elastic member prior to feeding of the paper whereby problems such as a "jam" condition, caused by skew feeding of the copy papers, can be prevented.

According to a feature of the present invention a cassette according to the invention may be constructed such that its reinforcing plates have elastic pieces mounted on the side walls thereof and when the cassette is loaded into the main body of a copying machine, the reinforcing function of the reinforcing plate is gradually generated and further the cassette can be stabilized with the aid of the reinforcing plate at the loaded position of the cassette. The invention makes it possible to avoid distortion or siiding of the copy papers as well as a failure in paper feeding such as skew feeding of papers which is caused as described above, and therefore a stable paper feeding can be expected.

A specific embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a perspective view illustrating one of the examples of large sized cassettes of the present invention, Figure 2 is a perspective view illustrating one of the examples of reinforcing plates to be used with the cassettes, and Figure 3 and Figure 4 are schematic illustrations showing the movements of the reinforcing plate when the cassette is loaded in the main body, Figure 4(a) shows the state of being loaded thereof, and, Figure 4(b) shows the state of complete loading thereof.

Figure 1 shows a large size cassette constructed in accordance with the present invention, wherein the cassette (20) is composed of a deep box assembled with a bottom plate (30), side walls (31 and 32), a front wall (33) and a rear wall (34). A base plate (35) is horizontally mounted above the bottom plate (30), and a number of copy papers (P) are stored on the base plate (35). The base plate (35) is elevated correspondingly to match the decrease in the height of the pile of copy papers in use, by means of a height adjustment device (not shown) which is arranged in the space between the bottom plate (30) and the base plate of the cassette, and thereby the uppermost sheet of paper can be held at approximately the same height.Gates (21 and 22) are formed at central parts of the side walls (31 and 32) respectively to facilitate loading and unloading of the paper whereby the operator can unload and load the papers by holding the side edge with his fingers. Separation claws (23, 23), which are movable vertically in slot (31 a, 31 a) formed on the side walls, are provided at both of the front corner portions of the paper storage section of the cassette (20).

Figure 2 shows a plate (24) which provides a narrow elongate reinforcing member. One such plate is pivotally mounted by means of pin (25) on the outer side of each side wall (31, 32) and hangs vertically downwards when the cassette is not loaded into the main body of copying machine, as illustrated in Figure 1. The reinforcing plate is made of plate metal. The reinforcing plate (24) is formed to have a bent portion (24a) along one side edge and a cassette holding piece (24b) and an elastic element (24c) are mounted on a side surface of the plate (24). The cassette holding piece (24b) comprises a thin resilient metallic member a part of which is positioned away from the side surface of the plate.The upper part of the elastic member (24c) is curved and the curved portion thereof extends above the upper edge of the reinforcing plate (24) as viewed in Figure 2, and the curved portion also protrudes by a small amount from the side wall (31) of the cassette in a direction inwardly of the cassette, and is brought into slight pressurizing contact with the side edge of the uppermost sheets of papers (P) stored in the cassette when the reinforcing plate (24) is brought in a horizontal position when the cassette has been loaded with papers. In Figure 1, only the reinforcing plate (24) mounted on one of the side walls (31) is shown, but a similar reinforcing plate is also mounted on the other side wall (32) in the same fashion.

The reinforcing action achieved at the time when the cassette is loaded in a copying machine will now be described with reference to Figure 3 and Figure 4.

When the cassette is loaded in the main body (26) of a copying machine, at first the roller (27a) which is rotatably mounted on pin (27) which in turn is mounted on the main body of the machine, is brought into contact with the bent portion (24a) of the reinforcing plate (24). When the cassette (20) is pushed further into the machine, the reinforcing plate (24) is pivotted about the pin (25) and the bent portion (24a) is guided by the roller (27a) as it is moved further into the main body (26) such that its angle to the horizontal is progressively decreased as the cassette (20) is pushed into the copying machine, the reinforcing plate (24) is pivotted until it extends nearly horizontally with the free end of the reinforcing plate (24) passing over the gate (21) and then reaching the portion of the side wall (31) of the cassette on the opposite side of the gate.

When the cassette (20) is compietely loaded in the main body (26), the reinforcing plate (24) lies in a horizontal position and at the same time the elastic holding piece (24b), which is mounted on the outside surface of the reinforcing plate (24), abuts a pin (28) protruding from the main body (26) so that the cassette is then subjected to elastic forces exerted on both sides thereof by the resilient deformation of the holding pieces (24b) and is thereby stably held.

The strength of the cassette (20) is enhanced by the reinforcing plate (24). The structural strength of the cassette (20) is weakened by cutting out the gates (21 and 22), so that twist thereof may occur on loading, but this is corrected by the reinforcing plate (24) which is pivotally mounted and bridges the gates formed in the side walls as mentioned above and the strength of the side walls is enhanced by the pressing forces exerted thereon by engagement of the elastic holding pieces (24b) and the pins (28). Therefore, the papers stored in the cassette (20) are fed stably by rotation of paper feed rollers (29, 29) which are located at a given stationary position on the main body (26).The elastic member (24c) mounted on the upper side edge of the reinforcing plate is brought into little pressurizing contact with the side edges of the uppermost sheets of papers including the top sheet so that skew feeding caused by a difference in pressure between the individual paper feed rollers (29 and 29), and that sheet can be corrected. The elastic member (24c) is mounted on the reinforcing plate as described above, and thereby can function to correct skew feeding without any need to unload papers from and to reload papers into the cassette.

The member (24) having the elastic member (24c) and cassette holding piece (24b) can be utilized in a cassette having a relatively shallow depth, e.g. as shown in Figure 1 of our British Patent Specification No. 2053159A (8017761) in place of the elastic members (3, 3) thereof.

Furthermore, the rollers (29, 29) shown jointed together to form an integrated unit may be provided by a single roller. Still further the relationship between the various elements, such as the mounting position of the elastic member with respect to the length of the side walls of the cassette, etc., can be determined by a suitable method, for example, by experiments.

The mechanism, for causing the reinforcing plate (24) to pivot to its position in which it acts on papers stored in the cassette to prevent skew feeding thereof, may comprise a pinion mounted on the reinforcing plate of the cassette to cooperate with a rack mounted on the main body and the bent portion of the reinforcing piece may be drawn into the inner part of the main body over the mechanism by guiding of the rollers. The cassette holding piece (24b) and the elastic member (24c) may in other embodiments be made of a suitable elastic material e.g. sponge, instead of sheet metal.

According to the above described embodiment, twisting which is apt to occur with a cassette having a gate cut out on a side wall thereof, can be corrected by locating a reinforcing plate provided on the wall across the gate as the cassette is loaded, and further it is possible to hold the cassette in a stable position and to stabilize the feeding of papers by subjecting the side walls of the cassette at its loaded position to lateral forces. A skew feed of papers can be avoided by arranging the elastic members on the reinforcing plate to be brought into a little pressurizing contact with the uppermost sheets of a supply of paper provided in the cassette.

The elastic member (24c) may have the form of the member shown in Figure 2(a) or Figure 2(b) of our British Patent Specification No.20531 59A (8017761) to which reference should be made for specific details of such constructions and also of the action of the elastic members in minimizing the problems of skew feeding of paper in copying machines.

Claims (6)

Claims

1. A paper feed cassette to be used in a copying machine, for storing a plurality of papers and having a box-like configuration with a base plate, side walls, a front wall and a rear wall, the cassette comprising gate means formed in its side walls, respectively, a reinforcement member mounted on each side wall, respectively, so as to be capable of pivotting to a position across a respective gate means, each reinforcement member having an elastic member arranged thereon to extend inwardly of the cassette, when the reinforcing member is positioned across its gate means, thereby to be in light pressure contact with the side edges of the uppermost sheets of papers stored, in use, in the cassette, the reinforcing member having a length more than the width of the respective gate means.

2. A paper feed cassette as claimed in Claim 1 wherein the cassette further comprises an elastic holding piece mounted on the outer surface of the reinforcement member so as to be resiliently engaged by a pressing member arranged on the main body of a copying machine as the cassette is loaded, in use, in the machine, thereby to maintain the cassette in a stable position.

3. A paper feed cassette as claimed in any preceding Claim wherein each elastic member is formed of a piece of strip metal.

4. A paper feed cassette as claimed in Claim 3 wherein the piece of strip metal has a portion formed so as to curve gradually inwardly of the general plane of the adjacent side wall of the cassette in the upward direction towards the open top of the cassette, when the reinforcing member is in its position across its respective gate means.

5. A paper feed cassette substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

6. A copying machine having a paper feed cassette as claimed in any preceding claim.