JP3613509B2 - Paper cassette - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper feed cassette used in an image forming apparatus.
[0002]
[Prior art]
In the image forming apparatus, a side fence is provided in a cassette case for paper feeding and the side edges of the paper are guided by the side fence in order to prevent the paper from tilting (hereinafter referred to as skew) during paper feeding. As a method for determining the position of the side fence, a fixed type in which the side fence is fixed to the bottom surface of the cassette case with a fastening member such as a screw or a pin, and a movable type in which the side fence is slidably supported and fixed at a desired position. There is. In the case of the fixed type, screw holes for tightening screws, holes for inserting pins and the like must be arranged in the cassette case at predetermined intervals, and the size of the paper to be used is limited to a standard size. On the other hand, in the case of the movable type, the position of the side fence can be changed continuously, so that any size paper can be used within a certain range, so the movable type is frequently used. .
[0003]
For example, as described in JP-A-8-169563, a high friction member pressed against a cassette case (paper feed tray) by the force of a spring, and the high friction member against the urging force of the spring. The side fence is provided with a fixing release lever that separates from the cassette case, and the side fence is moved while maintaining the state where the high friction member is detached from the cassette case by operating the fixing release lever. There is a case in which a side fence is fixed with a strong force to some extent by pressing a high friction member against the case with the force of a spring. This publication also describes that the side fence is more securely fixed at a fixed position by forming serrated irregularities meshing with each other on the opposing surfaces of the high friction member and the cassette case.
[0004]
However, the structure is not limited to that described in JP-A-8-169563, but the structure that releases the engaged state with the cassette case when the side fence is moved increases the number of parts and the manufacturing cost. It cannot be denied that it will be high.
[0005]
For this reason, a contact surface is formed in the cassette case in parallel with the width direction of the paper, and an elastic piece that elastically contacts the contact surface is formed integrally with the side fence. There is a paper feed cassette in which the side fence is fixed at a desired position by friction.
[0006]
[Problems to be solved by the invention]
The configuration in which the elastic piece of the side fence is brought into contact with the contact surface of the cassette case as described above, and the side fence is fixed at a desired position by the frictional force of both, and the side fence is caused by the pressure of the paper when the frictional force is small. It causes motion skew. Due to manufacturing variations, skew is particularly likely when the parallelism of the roller shaft is not maintained between a plurality of pairs of transport rollers arranged along the paper transport path. Conversely, if the frictional force is large, the operability when changing the position of the side fence is deteriorated. However, it is necessary to satisfy both the prevention of skew and the improvement of operability.
[0007]
Thus, although the side fence provided with the elastic piece is generally formed of a synthetic resin having elasticity, the elastic piece needs to have a thin structure in order to bend elastically. By the way, when the manufactured paper feed cassette is transported, it is stored in a narrow car at high density, and the car may be run for a long time under the hot weather or may be left unattended. It is not limited to transportation and may be stored for a long time in a high temperature environment. In either case, the temperature environment is severe. In this case, since the elastic piece of the side fence continues to bend under pressure from the cassette case under a high temperature environment, it is plastically deformed. Therefore, it is impossible to securely fix the side fence at the stage of actual use, and skew may occur.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 is provided with a cassette case that stores sheets in a stacked state and has a bottom surface formed with a contact surface parallel to the width direction of the sheet, and a guide surface that guides a side edge of the sheet; A side fence having a bendable elastic piece pressed against the abutting surface of the cassette case, and the side fence corresponding to a width size of the paper by contact friction between the abutting surface and the elastic piece. The paper feed cassette fixed at a desired position includes a removable elastic member that is formed of an elastically bending material and press-fitted into a long hole formed in the elastic piece.
[0009]
Therefore, the elastic piece bends due to the pressure from the contact surface of the cassette case, but when not in use such as transportation or storage, by maintaining it in a state supported by the elastic member press-fitted into the long hole of the elastic piece, It becomes possible to prevent plastic deformation of the elastic piece.
[0010]
The invention according to claim 2 comprises a cassette case that stores sheets in a stacked state and has a contact surface formed on the bottom surface parallel to the width direction of the sheets, and a guide surface that guides the side edges of the sheets; A side fence having a bendable elastic piece pressed against the abutting surface of the cassette case, and the side fence corresponding to a width size of the paper by contact friction between the abutting surface and the elastic piece. In the paper feed cassette that is fixed to a desired position, a relief recess that avoids contact with the elastic piece at a position other than a specified range that defines the width size of the paper is provided in the contact surface. Partly formed.
[0011]
Therefore, it is possible to eliminate the pressure that the elastic piece receives from the contact surface by maintaining the state that the side piece is positioned at the position where the elastic piece is opposed to the recess when not in use such as transportation or storage. It becomes.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of the paper feed cassette, and FIG. 2 is a longitudinal front view of the line AA in FIG. A cassette case 2 constituting one component of the paper feed cassette 1 is a box-like one with an open upper surface. The cassette case 2 in this example is mounted on an image forming apparatus (not shown) such as a copying machine so that the panel 3 formed on one side of the front side can be pulled out. It may be mounted on the image forming apparatus or mounted inside the image forming apparatus.
[0013]
Inside the cassette case 2, a bottom plate 4 that supports sheets fed in the sheet feeding direction (right side in FIG. 1) in a stacked state is provided so as to be able to rise and fall around a support shaft 5. The bottom plate 4 is urged upward by a spring (not shown) provided at the bottom of the cassette case 2. In addition, an end plate 6 that regulates the position of the rear end of the sheet is supported on the bottom of the cassette case 2 so as to be slidable and arbitrarily fixed along the guide groove 7.
[0014]
Further, the cassette case 2 is provided with a pair of side fences 8. These side fences 8 integrally have a guide surface 9 that guides both side edges of the paper and a rack 10 that extends inward from the lower edge of the guide surface 9 in parallel, and has elasticity. It is formed by. Further, the rack 10 of the pair of side fences 8 is formed with a long hole 11 and an elastic piece 12 whose elastic bending action is promoted by the long hole 11. A projection 13 is formed at the center of the elastic piece 12. Is formed. The cassette case 2 is formed with a recess 15 having a contact surface 14 with which the protrusion 13 of the elastic piece 12 contacts, and a pinion 16 meshing with the rack 10 is rotatably supported at the center of the recess 15. Yes.
[0015]
As shown in FIG. 2, projecting pieces 17 projecting downward are formed on the lower surface of the rack 10, and guide grooves 18 that support one surface of these projecting pieces 17 are formed in the recess 15 of the cassette case 2. These guide grooves 18 are parallel to the contact surface 14 and are determined to have such a length that the side fence 8 can be moved in the paper width direction within a certain range. Here, the distance a from the surface on the pinion 16 side of the guide groove 18 of the cassette case 2 to the contact surface 14 is set to a value smaller than the distance b from the surface on the pinion 16 side of the protrusion 17 to the protrusion 13. ing. That is, the projecting piece 17 and the guide groove 18 are slidably in contact with the surface on the pinion 16 side, and the protrusion 13 of the side fence 8 is in elastic contact with the contact surface 14.
[0016]
Further, an elastic member 19 that is detachably press-fitted into the long hole 11 of the rack 10 is provided. The elastic member 19 is formed of a material such as elastically bent rubber, and is packed together with the paper feed cassette 1 for delivery to the user after manufacture.
[0017]
In such a configuration, the elastic piece 12 is pressed against the contact surface 14 and the elastic piece 12 is elastically bent by the pressure from the contact surface 14 of the cassette case 2. When not in use, the elastic member 19 can be press-fitted into the long hole 11 of the rack 10, and the surface of the elastic piece 12 opposite to the contact surface 14 can be maintained in a state supported by the elastic member 19. That is, since the elastic piece 12 can be supported by the elastic member 19 against the pressure received by the elastic piece 12 from the contact surface 14, even if the paper feed cassette 1 is placed in a temperature environment higher than room temperature for a long time, Plastic deformation of the elastic piece 12 can be prevented.
[0018]
At the time of use at room temperature, the elastic member 19 is removed from the long hole 11, and the side fence 8 is moved in the width direction of the paper according to the width size of the paper to be used. At this time, the paired side fences 8 have the racks 10 meshed with the pinions 16, and thus move in directions toward or away from each other. There is a backlash between the rack 10 and the pinion 16, but the protrusion 13 of the elastic piece 12 maintained at an appropriate elasticity is brought into contact with the contact surface 14, and the side fence 8 is reliably secured by friction of the contact portion. Can be fixed.
[0019]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a plan view of the paper feed cassette. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is also omitted. In the present embodiment, when the minimum sheet to be used is, for example, a postcard size, the escape recess 20 that avoids contact with the elastic piece 12 at a position where the facing distance of the guide surface 9 is smaller than the postcard size is a contact surface. 14 is an example formed in a part of 14.
[0020]
In such a configuration, the elastic piece 12 abuts by maintaining the state in which the side fence 8 is positioned at the position where the protrusion 13 of the elastic piece 12 faces the relief recess 20 when not in use such as transportation or storage. Any pressure received from the surface 14 can be eliminated. Thereby, even if the paper feed cassette 1 is left in a temperature environment higher than normal temperature for a long time, the plastic deformation of the elastic piece 12 can be prevented.
[0021]
When used at room temperature, the side fence 8 is moved according to the width size of the paper to be used. At this position, the protrusion 13 of the elastic piece 12 is brought into contact with the contact surface 14, and the side fence 8 can be reliably fixed by the frictional force.
[0022]
【The invention's effect】
The invention according to claim 1 is a paper feed cassette that fixes the side fence to a position corresponding to the width size of the paper by contact friction between the contact surface formed on the cassette case and the elastic piece formed on the side fence. The elastic piece is formed of an elastically bending material and includes a removable elastic member press-fitted into a long hole formed in the elastic piece , so that the elastic piece bends due to pressure from the contact surface of the cassette case. When not in use such as transportation or storage, it can be supported by an elastic member that is press-fitted into the long hole of the elastic piece to prevent plastic deformation of the elastic piece, and the elastic member is removed during use to maintain proper elasticity The side fence can be securely fixed by bringing the elastic piece into contact with the contact surface.
[0023]
The invention according to claim 2 is a paper feed cassette that fixes the side fence to a position corresponding to the width size of the paper by contact friction between the contact surface formed on the cassette case and the elastic piece formed on the side fence. Transportation or storage is provided in the contact surface because a relief recess that avoids contact with the elastic piece at a position other than the specified range that defines the width size of the paper is formed in the side fence movement range. By maintaining the state in which the side piece is positioned at the position where the elastic piece faces the escape recess when the elastic piece is not used, the pressure received by the elastic piece from the contact surface can be completely eliminated. Thereby, plastic deformation of the elastic piece can be prevented, and the side fence can be reliably fixed by bringing the elastic piece maintained at proper elasticity into contact with the contact surface when in use.
[Brief description of the drawings]
FIG. 1 is a plan view of a paper feed cassette according to a first embodiment of the present invention.
FIG. 2 is a longitudinal front view of the AA line portion in FIG. 1;
FIG. 3 is a plan view of a paper feed cassette according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper feed cassette 2 Cassette case 8 Side fence 9 Guide surface 12 Elastic piece 14 Contact surface 19 Elastic member 20 Escape recessed part

Claims (2)

A cassette case that stores sheets in a stacked state and has a contact surface formed on the bottom surface parallel to the width direction of the sheet, a guide surface that guides a side edge of the sheet, and the contact surface of the cassette case A side fence having a bendable elastic piece pressed against the sheet, and fixing the side fence at a desired position corresponding to the width size of the paper by contact friction between the contact surface and the elastic piece. In the paper cassette,
A sheet feeding apparatus comprising a removable elastic member formed of an elastically bending material and press-fitted into a long hole formed in the elastic piece. A cassette case that stores sheets in a stacked state and has a contact surface formed on the bottom surface parallel to the width direction of the sheet, a guide surface that guides a side edge of the sheet, and the contact surface of the cassette case A side fence having a bendable elastic piece pressed against the sheet, and fixing the side fence at a desired position corresponding to the width size of the paper by contact friction between the contact surface and the elastic piece. In the paper cassette,
An escape recess that avoids contact with the elastic piece is formed in a part of the abutting surface at a position other than a specified range that determines the width size of the paper in the movement range of the side fence. Paper feeder.

Images