JPH08239129A - Paper feeding cassette - Google Patents

Abstract

PURPOSE: To provide a paper feeding cassette which prevents paper from being fed improperly, while restraining an increase in cost as far as possible. CONSTITUTION: Side fences 2, 3, which move in a direction perpendicular to the direction of paper feeding while being equally spaced about a pinion gear 5 as a center, are placed inside a front loading type paper feeding cassette 1. The rear side fence 3 is provided with a lock means 6, while the front side fence 2 is not provided with a lock means nor reinforced. The load resistance of the rear side fence 3 is thereby made greater than that of the front side fence 2 at reduced cost to prevent the rear side fence 3 from moving or deflecting due to paper load at the insertion of the cassette, thus preventing improper feeding of paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed cassette mounted in an image forming apparatus such as a copying machine, a printer or a facsimile.

[0002]

2. Description of the Related Art In recent years, there has been a demand for space saving of image forming apparatuses such as copying machines, printers and facsimiles.
A so-called front loading type device, in which a paper feeding cassette (or tray) that can be pulled out in a direction orthogonal to the paper feeding direction is attached to the main body of the device, is mainly used. A paper feed cassette used in this front-loading type image forming apparatus generally includes a pair of side fences on the front side and the back side of the apparatus that regulate both sides in the paper width direction (direction orthogonal to the paper feeding direction). An end fence that regulates the trailing edge of the sheet (the trailing edge in the sheet feeding direction) is provided to prevent misalignment of the transfer sheet stacked in the cassette and to position the sheet.

[0003]

However, in the case of the front-loading type image forming apparatus, when the paper feed cassette is set in the apparatus main body (the paper feed cassette is inserted into the apparatus main body), There is a problem in that the weight is applied to the back side fence, the side fence is displaced or bent, and the stacked sheets are displaced, so that a paper feed failure such as a paper jam or a skew occurs.

The present invention solves the above-mentioned problems in the conventional paper feed cassette used in the front-loading type image forming apparatus, and provides a paper feed cassette in which a paper feed defect is prevented while suppressing an increase in cost as much as possible. This is an issue.

[0005]

According to the present invention, there is provided a paper feed cassette which is mounted on an image forming apparatus and which can be pulled out and inserted in a direction orthogonal to the paper feed direction. In a paper feeding cassette having a back side fence and a front side fence for restricting both sides in the width direction of stored paper, the load resistance against the load applied to the side fence from the stored paper when the cassette is pulled out and inserted is set to the back side. This is solved by setting the side fence to be larger than the front side fence.

Further, in order to solve the above-mentioned problems, the present invention provides that the back side fence and the front side fence have a space into which the shaft portion of the sheet pushing-up bottom plate is fitted, and the front side fence has a gap. It is proposed that the void has an opening above the side fence, and the void of the back side fence has a shape that does not have an opening above the side fence.

Further, in order to solve the above-mentioned problems, the present invention proposes to dispose a spacer between the back side fence and the cassette side wall.

[0008]

The load resistance against the load applied to the side fence from the stored sheets when the cassette is pulled out and inserted is set so that the back side fence is larger than the front side fence. As a result, even if the paper load is applied to the back side fence when the cassette is inserted, the back side fence is prevented from being displaced or bent. Further, since it is not necessary to reinforce the front side fence, the cost increase can be suppressed as much as possible.

Other effects will be apparent from the description of the embodiments below.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a schematic structure of an embodiment of the present invention. The sheet feeding cassette 1 shown in this figure is mounted in a front loading type image forming apparatus, and is pulled out and inserted in the vertical direction of the figure. On the substrate 8 of the paper feed cassette 1, an end fence 4 for controlling the rear end of the transfer paper is attached. Further, a pair of front and rear side fences (on the front side and the back side of the apparatus) for restricting both sides in the width direction of the transfer paper are slidably arranged in a direction orthogonal to the paper feeding direction (left and right direction in the drawing). Has been done. That is, the side fences 2 and 3 have horizontal extending portions 2a and 3a, and the horizontal extending portion 2
Rack teeth are provided on the opposing surfaces of a and 3a. Then, the racks of both side fences 2 and 3 are meshed with the pinion gear 5 pivotally mounted on the substrate 8, and the side fences 2 and 3 move while maintaining equal distances from the center of the gear 5 (from the sheet conveyance standard). To do. A bottom plate for stacking sheets and pushing the sheets to the sheet feeding position is provided on the horizontally extending portions 2a and 3a of the side fences 2 and 3, but they are not shown in the drawing.

In the case of the front-loading type image forming apparatus, when the cassette is inserted, the load of the loaded sheets is applied to the back side fence. Therefore, in the present embodiment, in a paper feeding cassette having a side fence configured to be movable by using a rack and a pinion gear, the locking means normally provided on the front side fence is provided with the locking means of the rear side fence 3 of the apparatus. It is provided as the lock means 6. As a result, the load resistance of the side fence 3 on the back side of the apparatus is made larger than the load resistance of the side fence 2 on the front side, and even when the load of the paper is applied to the back side fence 3 when the cassette is inserted, The deviation and bending of the fence 3 are suppressed to prevent the occurrence of paper feeding failure. Moreover,
Since the side fence 2 on the front side is not particularly reinforced or provided with a locking means, the cost does not increase.

Next, another embodiment of the present invention will be described.

In the paper feed cassette 11 shown in FIG. 2, a pair of side fences 12 and 13 are slidably arranged in a direction orthogonal to the paper feed direction, as in the above embodiment. In this embodiment, the side fence 13 on the back side is provided with two screw holes, and the cassette substrate 8 has screw holes (not shown) at positions corresponding to the screw holes for each paper size. Is provided. Then, the side fences 12 and 13 are moved according to the sheet size to adjust the positions, and then the side fence 13 on the back side is screwed to the substrate 8 with screws (or rivets) 7. This allows
Even if the load resistance of the side fence 13 on the back side of the apparatus is set to be larger than that of the side fence 12 on the front side, and the load of the paper is applied to the back side fence 13 when the cassette is inserted, It suppresses misalignment and bending to prevent the occurrence of defective paper feed. Moreover, since the front side fence 12 is not particularly reinforced or provided with locking means, the cost does not increase.

Next, another embodiment of the present invention will be described.

FIG. 3 is a partial sectional view showing the back side fence of the paper feed cassette of this embodiment. The back side fence 23 shown in this figure is made of a resin material and has fixing claw portions 23a provided at both ends in the sheet feeding direction. Then, the claw portion 23a is inserted into the slit 8a of the cassette substrate, and the horizontal portion 23b of the side fence is further inserted.
Are fixed to the substrate 8 with screws (or rivets) 7. The front side fence (not shown) is fixed by inserting the fixing claw portion into the slit of the cassette substrate without screwing. As a result, the load resistance of the side fence on the back side of the apparatus is made larger than the load resistance of the side fence on the front side while suppressing the cost, and the occurrence of paper feeding failure when inserting the cassette is prevented.

FIG. 4 is a cross-sectional view of the back side fence for explaining still another embodiment of the present invention. The side fences 31 to 36 shown in this figure are formed by forming a vertical wall surface portion that abuts the side surface of the stacked sheets and a horizontal portion into an inverted T-shape or a substantially L-shape in cross section, and have a thickness of the cross section. By making it thicker than the conventional one, the load resistance of the back side fence is increased. The side fence 31 shown in (a) has an inverted T-shaped cross section, and the side fence 32 in (b) has an inverted T-shaped cross section and has a void 32a in the wall surface.
The side fence 33 of (c) has an L-shaped cross section, the side fence 34 of (d) has a substantially L-shaped cross section in which a horizontal portion is provided at the upper end of the wall surface portion, and the side fence 35 of (e) has The side fence 36 of (f) is also L-shaped in cross section and has a void 36a opened laterally in the wall surface. The front side fence (not shown) is the same as the conventional one without changing the sectional thickness or the like. As a result, the load resistance of the side fence on the back side of the apparatus is made larger than the load resistance of the side fence on the front side while suppressing the cost, and the occurrence of paper feeding failure when inserting the cassette is prevented.

FIG. 5 shows a case where one of the back side fences of this embodiment is applied to a corner claw type sheet feeding cassette. That is, the member 14 having the corner claws 14a is attached to the wall surface portion of the rear side fence 33 having the increased load resistance. In the case of a corner claw type paper feed cassette, if the back side fence is misaligned or bent when it is inserted into the main unit, the paper will come off the corner claws, causing paper jams and skew. It is especially effective for the paper feed cassette of the method.

FIG. 6 shows still another embodiment of the present invention. That is, in this figure, the back side fence 37 shown in (a) has an inverted T-shaped cross section,
The back side fence 38 shown in (b) has an inverted T-shaped cross section and has a shape with a gap in the wall surface. Then, both of the reinforcing triangular ribs 37a, 3 are provided between the wall surface portion and the horizontal portion.
8a is provided. For the front side fence (not shown), the same one as the conventional one is used without providing reinforcing ribs.
As a result, the load resistance of the side fence on the back side of the apparatus is made larger than the load resistance of the side fence on the front side while suppressing the cost, and the occurrence of paper feeding failure when inserting the cassette is prevented. A triangular rib may be provided on the outside of the back side fence having an L-shaped cross section.

FIG. 7 shows still another embodiment of the present invention. The back side fence 43 shown in this figure is provided with a gap 43a for passing a rotating shaft portion of a bottom plate (paper pushing plate) (not shown). As shown in FIG. 11, the side fence of the conventional paper feed cassette is provided with a space 63a that opens upward in the wall surface portion of the side fence 63 in order to improve workability during assembly, and the rigidity of the wall surface portion is improved. Was falling. However, since the gap 43a provided in the back side fence 43 in the present embodiment does not open in any direction other than the bottom plate rotation axis direction, the rigidity of the wall surface portion is not reduced, and the back side fence is not reduced. The load resistance of the fence 43 can be improved. The front side fence (not shown) may be the same as the conventional one that is open above the wall surface. As a result, the load resistance of the side fence on the back side of the apparatus is made larger than the load resistance of the side fence on the front side while suppressing the cost, and the occurrence of paper feeding failure when inserting the cassette is prevented. In addition, as shown in FIG. 8, the back side fence 5 having the same shape as the conventional one.
Alternatively, the upper portion of the void 53a may be closed by the reinforcing plate 54. In this case, the cost of parts can be further reduced, and the reinforcing plate 5 can be installed after the bottom plate is assembled.
Since 4 can be attached, workability at the time of assembly is not impaired.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to 10.

As shown in FIGS. 9 and 10, in this embodiment, a spacer 10 is provided between the side fence 63 on the far side and the cassette side wall 9. This prevents the side fence 63 from being displaced or bent when the cassette is inserted. A spacer is not provided on the front side fence (not shown), and the same one as the conventional one is used. As a result, the load resistance of the side fence on the back side of the apparatus is made larger than the load resistance of the side fence on the front side while suppressing the cost, and the occurrence of paper feeding failure when inserting the cassette is prevented.

By the way, the side fence 63 is constructed so as to be movable according to the paper size. Further, the spacer 10 has a rectangular shape in plan view, and when the paper size is A3, as shown in FIG. 9, the spacer 10 is arranged such that its side in the longitudinal direction is along the side fence 63 and the cassette side wall 9. Then, when the sheet size is A4, as shown in FIG. 10, the side in the lateral direction is arranged along the side fence 63 and the cassette side wall 9. With this configuration, one spacer 10 can handle different size sheets, and the cost can be prevented from increasing. Further, if the thickness of the spacer 10 is set to a thickness corresponding to another sheet size, for example, B5 size, one spacer 10 can correspond to three types of sheet sizes, which is further advantageous.

[0024]

As described above, according to the image forming apparatus of the present invention, even when the paper load is applied to the back side fence when the cassette is inserted, the back side fence is prevented from being displaced or bent, and the front side fence is prevented. Since it is not necessary to reinforce the side fences, the cost increase can be suppressed as much as possible.

According to the second aspect of the present invention, since the shaft portion fitting space of the paper pushing-up bottom plate provided on the back side fence has a shape having no opening upward, the rigidity of the back side fence is increased. The load resistance can be improved.

According to the structure of claim 3, since the spacer is arranged between the back side fence and the side wall of the cassette, the load resistance of the back side fence can be improved with a simple structure.

[Brief description of drawings]

FIG. 1 is a plan view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a plan view showing a schematic configuration of another embodiment of the present invention.

FIG. 3 is a partial cross-sectional view showing a back side fence for explaining still another embodiment of the present invention.

FIG. 4 is a cross-sectional view of a back side fence for explaining still another embodiment of the present invention, (a),
(B) is a side fence having an inverted T-shaped cross section,
(F) shows a side fence having a substantially L-shaped cross section.

FIG. 5 is a perspective view showing a side fence of the embodiment applied to a corner claw type sheet feeding cassette.

FIG. 6 is a cross-sectional view of a back side fence for explaining still another embodiment of the present invention, in which (a) is an inverted T-shaped cross section and (b) is a void in a wall surface portion. 3 shows side fences each having a reinforcing rib, the side fence having a shape with a groove.

FIG. 7 is a perspective view of a back side fence for explaining still another embodiment of the present invention.

FIG. 8 is a perspective view showing a modified example of the embodiment.

FIG. 9 is a partial plan view for explaining still another embodiment of the present invention, showing a case corresponding to A3 size paper.

FIG. 10 is a partial plan view showing a case corresponding to A4 size paper in the embodiment.

FIG. 11 is a perspective view showing a side fence for explaining an example of a conventional paper feed cassette.

[Explanation of symbols]

 1, 11 Paper feed cassette 2, 12 Front side fence 3, 13, 23 Back side fence 4 End fence 5 Pinion gear 6 Locking means 7 Screw (or rivet) 8 Cassette board 9 Cassette side wall 10 Spacer 14 Corner claws 31-38 Back side fence 43,53,63 Back side fence

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H04N 1/00 108 H04N 1/00 108C

Claims (3)

[Claims] 1. A paper feed cassette which is mounted on an image forming apparatus and which can be pulled out and inserted in a direction orthogonal to a paper feed direction, the paper feed cassette being provided in parallel with the paper feed direction and for restricting both widthwise sides of stored paper. In a paper feeding cassette having a back side fence and a front side fence, the load resistance against the load applied to the side fence from the stored sheets when the cassette is pulled out and inserted is greater in the back side fence than in the front side fence. A paper cassette characterized by being set to be large. 2. The back and front side fences have a space into which the shaft portion of the sheet lifting bottom plate is inserted, and the space of the front side fence has an opening above the side fence. The sheet feeding device according to claim 1, wherein the void of the back side fence has a shape having no opening above the side fence. 3. The image forming apparatus according to claim 1, wherein a spacer is provided between the back side fence and the cassette side wall.