JP2007091440A - Paper feed cassette and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent paper feeding failure caused by overload of sheet material by surely making installation of a paper feed cassette in an image forming device impossible without requiring a special operation when the sheet material is overloaded on the paper feed cassette. <P>SOLUTION: When loaded sheet material S is higher than the maximum loading position, a short piece 11a of an overload preventing member 11 abuts on the sheet material S, and cannot rotate to an original position. Thus, a long piece 11b of the overload preventing member 11 is left protruded outside a sheet material filling space 21 in an approximately horizontal state. Therefore, when installing the paper feed cassette 1 in an image forming device main body 13, the long piece 11b of the overload preventing member 11 abuts on an erroneous installation preventing member 18, and therefore the paper feed cassette 1 cannot be installed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a paper feed cassette that is detachably attached to an image forming apparatus that forms an image on a sheet material such as a printer or a copying machine.

  An image forming apparatus that forms an image on a sheet material, such as a printer or a copying machine, is generally provided with a paper feed cassette on which a large number of sheet materials can be stacked.

  In such an image forming apparatus, in order to prevent an excessive stacking of sheet materials on the sheet feeding cassette, the maximum stacking position of the sheet materials in the sheet feeding cassette is indicated by a line or the like to the user. . However, in order to prevent the sheet material from running out of the sheet cassette, the user tries to stack as many sheet materials as possible on the sheet cassette at one time. For this reason, the line indicating the maximum stacking position is ignored, and sheet materials exceeding the maximum stacking position may be forcibly stacked (hereinafter referred to as “overload”).

  By the way, the paper feed roller that feeds the sheet material stacked in the paper cassette is designed on the assumption that a predetermined number of sheet materials are stacked. If this occurs, the operation of the paper feed roller may become defective. As a result, paper feed defects such as paper jams and double feed in which two or more sheets are fed simultaneously occur. There is.

  Thus, several methods for preventing such overloading on the paper feed cassette have been proposed.

  For example, Patent Document 1 proposes a load amount regulating plate 101 as shown in FIG. FIG. 9 is a cross-sectional explanatory view of the rear end regulating plate of the paper feed cassette. The overload prevention means proposed in Patent Document 1 will be outlined below with reference to FIG.

  The rear end regulating plate 100 that regulates the rear end position of the sheet material is provided with a notch 100a at the upper center portion, and the stacking amount regulating plate 101 is disposed in the notch 100a. Both ends of the loading amount regulation plate 101 are rotatably supported by the rear end regulation plate 100, and can be rotated between a solid line position (first position) and a two-dot chain line position (second position). . When the stacking amount regulating plate 101 is in the first position, it can be engaged with the locking plate 102 to fix the rear end regulating plate 100.

  When the sheet material is set in the paper feed cassette 103, the stacking amount regulating plate 101 is rotated to the second position, the rear end regulating plate 100 is moved to the target position, and then the sheet material S is inserted from above. Then, the load amount restricting plate 101 is operated and rotated to the first position, and the rear end restricting plate 100 is fixed. At this time, when the height of the sheet material S exceeds the maximum stacking position, the leading end of the stacking amount regulating plate 101 is pushed up by the sheet material S, and the first position which is the normal position can be taken. Thus, the user can understand the overloading of the sheet material S. Accordingly, it is possible to prevent the sheet material S from being forcibly set and to prevent a paper feed failure due to overloading.

  Patent Document 2 proposes a rotating member 202 as shown in FIG. FIG. 10 is an enlarged schematic view showing a part of the paper feed cassette. Hereinafter, the overload prevention means proposed in Patent Document 2 will be outlined with reference to FIG.

  A plate-like rotating member 202 is rotatably fixed to the central portion in the width direction of the upper portion of the rear end regulating plate 201 of the paper feed cassette 200, and the front end portion 202a is inclined slightly upward.

  When the height of the stacked sheet material S exceeds the maximum stacking position, the excess sheet material S pushes up the rotating member 202 and rotates it in the direction of arrow F. In this case, the rotating member 202 is positioned at a position (a position indicated by a two-dot chain line in FIG. 10) higher than a position (a position indicated by a solid line in FIG. 10) when a predetermined number or less of sheet materials S are stacked. It becomes.

Therefore, since the rotating member 202 hits the upper wall 203 when it is overloaded, the sheet feeding cassette 200 cannot be mounted, and it is possible to prevent a sheet feeding failure due to overloading.
Japanese Patent Laid-Open No. 11-165848 (FIGS. 1 to 3) JP 2003-104571 A (FIGS. 9 and 10)

  However, in Patent Document 1, after the sheet material is stacked on the sheet feeding cassette, the user himself / herself has to operate (rotate) a stacking amount regulating plate for preventing overloading of the sheet material. It was not good.

  Further, in Patent Document 2, it is difficult for the user to understand whether or not the rotating member is overloaded from the position of the rotating member, and even if the rotating member hits the upper wall due to overloading of the sheet material, the paper feeding cassette is forcibly pushed. It is also possible to wear it.

  In the present invention, in view of the above-described circumstances, when a sheet material is overloaded on the sheet feeding cassette, it is not necessary to perform a special operation and the sheet feeding cassette cannot be reliably mounted on the image forming apparatus. Therefore, an object is to prevent sheet feeding defects due to overloading of sheet materials.

  To achieve the above object, the present invention provides a sheet material filling space for loading and filling a sheet material in an area of the same size as the sheet material, and a range of the sheet material filling space in the width direction of the sheet feeding cassette. And a L-shaped movable member provided above a maximum stacking position of the sheet material on the regulation plate, and the movable member is a sheet stacked in the sheet material filling space. When the height of the material is less than or equal to the maximum loading position, one piece projects horizontally into the sheet material filling space, and the other piece takes a basic posture along the outer surface of the regulating plate, and the sheet material filling When the height of the sheet material stacked in the working space exceeds the maximum stacking position, one piece comes into contact with the sheet material and retreats from the sheet material filling space, and the other piece is the sheet material filling space. Project outside Wherein the take retracted position.

  Then, when the sheet material is filled, the movable member can be brought into the retracted position without requiring a special operation by allowing one piece of the movable member to be pushed down by the falling sheet material so that the retracted position can be taken. The sheet material can be filled smoothly.

  Further, according to the present invention, in such an image forming apparatus in which the paper feed cassette is detachably attached to the main body, the sheet material is excessive depending on the presence or absence of contact with the other piece of the movable member when the paper feed cassette is attached. It is characterized by comprising erroneous mounting preventing means for preventing erroneous mounting of the stacked paper feed cassettes. According to this, even when a sheet cassette loaded with the sheet material height exceeding the maximum stacking position, that is, a sheet cassette overloaded with sheet material, is mistakenly mounted on the image forming apparatus main body, the retracted position is maintained. Since the other piece of the movable member is in contact with the erroneous mounting preventing means and cannot be mounted, such erroneous mounting can be reliably prevented.

  According to the present invention, it is possible to reliably prevent the sheet feeding cassette on which the sheet material is overloaded from being erroneously attached to the main body of the image forming apparatus. It is possible to prevent sheet feeding defects such as double feeding in which the above sheet materials are fed simultaneously.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing an overall configuration of a paper feed cassette 1 according to the present invention, and FIG. 2 is a schematic perspective view showing a state when the paper feed cassette 1 is mounted on an image forming apparatus main body 13. As shown in FIG. 1, the paper feed cassette 1 is rotatably supported by a bottom wall 2, a pair of opposite side walls 3 and 4 that define the width of the paper feed cassette, and both side walls 3 and 4, In addition, a bottom raising member 5 on which the sheet material S (not shown) is stacked is provided.

  The bottom raising member 5 is substantially U-shaped from a bottom plate 51 on which the sheet material S is stacked and a pair of side plates 52 and 53 formed so as to be bent vertically from both side edges of the flat portion 51a of the bottom plate 51. , And are supported by the rear end portions 52a and 53a of the side plates 52 and 53 with respect to the side walls 3 and 4 using the rotation fulcrums 6 and 7, respectively. The front end portion 51 b of the bottom plate 51 has a downward slope, and a biasing means such as a compression spring (not shown) is disposed between the lower surface of the front end portion 51 b and the upper surface of the bottom wall 2. As a result, the bottom raising member 5 is pivoted about the pivot fulcrums 6 and 7, and the front end portion of the sheet material S stacked on the bottom plate 51 is pushed up. In addition, short openings 54 and 55 are respectively formed at both sides of the center of the flat portion 51a of the bottom plate 51.

  Further, on the inner side of the side walls 3, 4, a pair of side end regulating plates 8, 9 for regulating the width direction end (side end) of the sheet material S, and a sheet behind the bottom raising member 5 (in the direction of arrow A) A rear end regulating plate 10 for regulating the rear end of the material S is disposed on the bottom wall 2. Both side end regulating plates 8, 9 are integrally formed in a substantially L shape by bottom plates 81, 91 (see FIG. 3) and side plates 82, 92 formed so as to be bent vertically upward from one side end of the bottom plate. The side plates 82 and 92 are attached to the bottom wall 2 by the bottom plates 81 and 91 so as to penetrate the bottom plate 51 through the openings 54 and 55 of the bottom plate 51 of the bottom raising member 5. As will be described later, overload prevention members (movable members) 11 and 12 are disposed on the upper portions of the side end regulating plates 8 and 9, respectively.

  Further, on the outer surfaces of the side walls 3 and 4, ridges 14 and 15 are integrally formed so as to extend in the mounting direction of the sheet feeding cassette 1 to the image forming apparatus main body 13 (direction of arrow A). On the other hand, as shown in FIG. 2, at the lower part of the main body 13 of the image forming apparatus, a space is opened in the front surface of the main body 13 and the paper cassette 1 is detachably mounted (hereinafter referred to as a paper cassette mounting portion). 13a is formed, and guide rails 16 and 17 for guiding the protrusions 14 and 15 when the paper feed cassette 1 is attached and detached are disposed on the main body 13 on both sides of the paper feed cassette mounting portion 13a. In order to prevent erroneous mounting of the paper feeding cassette 1 on the upper part of both sides of the opening side of the paper feeding cassette mounting portion 13a by the presence or absence of contact with the overload prevention members 11 and 12 when the paper feeding cassette 1 is mounted. The erroneous mounting preventing members 18 and 19 are provided.

  FIG. 3 is a cross-sectional view (cross-sectional view taken along the line BB) of the paper feed cassette 1 taken along the alternate long and short dash line in FIG. 1, and FIGS. The expansion perspective view of the periphery of the overload prevention member 11 arrange | positioned is shown. The overload prevention member will be described in more detail with reference to FIGS. 3, 4A and 4B. For convenience of explanation, only the overload preventing member 11 disposed on the right side end regulating plate 8 in FIG. 3 will be noted below, and the overload preventing member disposed on the left side end regulating plate 9 will be described. The description of 12 is omitted, but the configuration is the same except that both are symmetrically arranged.

  A short notch 83 having a height H is provided on the upper portion of the side end regulating plate 8, and the bottom surface of the notch 83 is slightly behind the notch 83 (in the direction of arrow A). The upper limit mark 20 is shown that indicates the maximum stacking position of the sheet material S at the same height as the horizontal line and two inverted triangles.

  The overload preventing member 11 stacks and fills the sheet material S in an area of the same size as the sheet material S surrounded by the side end regulating plates 8 and 9 and the rear regulating plate 10 (see FIG. 1) of the sheet feeding cassette 1. A short piece 11a which is located inside a space (hereinafter referred to as a sheet material filling space) 21 and whose length is set to L1 shorter than H, and is located outside the sheet material filling space 21 and is long Are integrally formed in an L shape so that the long piece 11b whose length is set to L2 longer than L1 and H forms a right angle. Then, the overload preventing member 11 is supported by the side end regulating plate 8 by pivotally supporting the rotating shaft 11c protruding from the connecting portion of the short piece 11a and the long piece 11b to the bearings 22 provided at both upper ends of the notch 83. Is supported rotatably.

  Here, the overload prevention member 11 is designed so that the long piece 11b is heavier than the short piece 11a. Normally, the short piece 11a is caused by its own weight as shown in FIG. It protrudes horizontally into the sheet material filling space 21, and the long piece 11 b takes a basic posture along the outer surface of the side end regulating plate 8.

  The overload prevention member 11 rotates in the direction of the arrow C so that the short piece 11a can be stored in the notch 83, but the notch 83 provided on the side end regulating plate 8 has a bottom surface. A rotation stopper 83a with a part raised is provided, and the rotation of the overload prevention member 11 is limited to 90 ° because further rotation is prevented by the short piece 11a coming into contact with the rotation stopper 83a. Will be.

  Hereinafter, the operation of the overload prevention member 11 when the sheet material S is set in the paper feed cassette 1 will be described. 5 to 7 are enlarged sectional views of the periphery of the overload preventing member 11 disposed on the side end regulating plate 8 shown in FIG. 3, and for the sake of convenience of explanation as in FIG. 4, the right side end in FIG. Focusing only on the overload prevention member 11 disposed on the restriction plate 8, the description of the overload prevention member 12 disposed on the left side end restriction plate 9 is omitted. FIG. 8 is a schematic perspective view showing a state when the sheet feeding cassette 1 on which the sheet material S is overloaded is mounted on the image forming apparatus main body 13.

  As described above, the overload preventing members 11 and 12 are normally protruded into the sheet material filling space 21 by the short pieces 11a and 12a of the both overload preventing members 11 and 12 as shown in FIG. The long pieces 11b and 12b of the stacking prevention members 11 and 12 take a basic posture along the outer surfaces of the side end regulating plates 8 and 9.

  At this time, as shown in FIG. 2, the width of the upper portion of the sheet feeding cassette 1 is such that the long pieces 11 b of the overload preventing members 11, 12 positioned along the outer surfaces of the side end regulating plates 8, 9. It becomes W1 (refer FIG. 3) prescribed | regulated by the distance between the outer surfaces of 12b. The width W1 is set so as to be shorter than the interval D between the erroneous mounting preventing members 18 and 19 disposed on both upper sides on the opening side of the sheet feeding cassette mounting portion 13a formed in the image forming apparatus main body 13. ing. Therefore, when the paper feed cassette 1 is to be mounted on the image forming apparatus main body 13, the long pieces 11 b and 12 b of both the overload prevention members 11 and 12 are normally mounted without coming into contact with the erroneous mounting prevention members 18 and 19. can do.

  When a bundle of sheet materials S is set on the bottom raising member 5, the sheet material S is filled from above the sheet feeding cassette 1 as indicated by an arrow E in FIG. At this time, as shown in FIG. 5, the short piece 11a of the overload prevention member 11 is pushed down by the falling sheet material S, and the overload prevention member 11 rotates to the position indicated by the dotted line in the counterclockwise direction around the rotation shaft 11c. Take a posture. Then, the short piece 11 a of the overload preventing member 11 is accommodated in the notch portion 83 provided in the side end regulating plate 8 and is retracted from the sheet material filling space 21. Thereby, the sheet material S can be set on the bottom raising member 5 without being blocked by the short piece 11a of the overloading prevention member 11. At this time, the long piece 11b of the overload preventing member 11 protrudes substantially horizontally outside the sheet material filling space 21.

  Then, after the sheet material S is set on the bottom raising member 5, the height of the sheet material S is the maximum stacking position, that is, the upper limit mark 20 shown on the inner surface of the side end regulating plate 8 (FIG. ) See below) If there is no obstruction that hinders the movement of the short piece 11a of the overload prevention member 11 above the portion of the sheet material filling space 21 where the sheet material S is stacked, the overload prevention The member 11 can rotate in the direction opposite to the above-described rotation direction by the dead weight of the long piece 11b, and can return to the original position as shown in FIG. This also applies to the overload prevention member 12 disposed on the left side end regulating plate 9 in FIG.

  Therefore, when the sheet material is filled, the long pieces 11b and 12b of the overload prevention members 11 and 12 that are positioned so as to protrude substantially horizontally outside the sheet material filling space 21 are the side end regulating plates as in the normal case. 8 is located along the outer surface. Therefore, as described above, the paper feed cassette 1 can be normally attached to the image forming apparatus main body 13.

  However, when the height of the sheet material S stacked on the bottom raising member 5 exceeds the maximum stacking position, that is, the upper limit mark 20 illustrated on the inner surface of the side end regulating plate 8, when the sheet material is filled. Even if the overloading prevention member 11 that has been retracted from the sheet material filling space 21 tries to rotate to the original position, the short piece 11a of the overloading prevention member 11 exceeds the maximum loading position as shown in FIG. Since the sheet material S is in contact with the stacked sheet material S, the overload preventing member 11 cannot rotate to the original position. Therefore, the long piece 11b of the overload prevention member 11 remains in a state of protruding substantially to the waterside outside the sheet material filling space 21. This also applies to the overload prevention member 12 disposed on the left side end regulating plate 9 in FIG.

  At this time, as shown in FIG. 8, the width of the upper portion of the sheet feeding cassette 1 is such that the long pieces 11b, 12b of the overload preventing members 11, 12 projecting substantially horizontally outside the sheet material filling space 21. W2 defined by the distance between the tips. This width W2 is set so as to be longer than the interval D between the erroneous mounting preventing members 18 and 19 provided in the paper feed cassette mounting portion 13a formed in the image forming apparatus main body 13. Therefore, even when trying to mount the paper feed cassette 1 on the image forming apparatus main body 13, the long pieces 11 b and 12 b of both the overload preventing members 11 and 12 come into contact with the erroneous mounting preventing members 18 and 19. Cannot be performed (see FIG. 8). Accordingly, it is possible to reliably prevent the sheet feeding cassette 1 on which the sheet material S is overloaded from being erroneously attached to the image forming apparatus 13.

  As described above, by preventing the sheet cassette 1 with the sheet material S being overloaded from being mounted on the image forming apparatus main body 13, it is possible to prevent a sheet feeding failure caused by the sheet material S being overloaded. .

  In addition, this invention is not limited by the said embodiment. For example, in the above-described embodiment, the case where the overload prevention member is designed so that the long piece is heavier than the short piece and is designed to spontaneously return to the original position by the weight of the long piece after filling with the sheet material has been described. Alternatively, a biasing means such as a hinge spring may be separately provided on the rotation shaft of the overload prevention member to forcibly return to the original position. Further, as in the above-described embodiment, instead of providing the main body of the image forming apparatus with an erroneous attachment prevention member that contacts the long piece of the overload prevention member when the sheet material is overloaded, the supply formed in the image forming apparatus is not provided. It is also possible to change the mouth shape of the opening of the paper cassette mounting portion to have the same function as the erroneous mounting preventing member. Furthermore, in the above-described embodiment, the push-up mechanism of the bottom raising member provided in the paper feed cassette has been described in which the urging means such as a compression spring is disposed on the lower surface of the bottom raising member. After the paper feed cassette is mounted on the main body of the image forming apparatus, the rotary plate arranged in contact with the lower surface of the bottom raising member may be rotated by driving from the main body side.

  The present invention can be used for a paper feed cassette that is detachably attached to an image forming apparatus that forms an image on a sheet material such as a printer or a copying machine.

These are the perspective views which show the whole structure of the paper feed cassette which concerns on this invention. FIG. 4 is a schematic perspective view showing a state when the paper feed cassette is mounted on the image forming apparatus main body. FIG. 2 is a cross-sectional view (a cross-sectional view taken along line BB) when the paper feed cassette is cut at a position indicated by a one-dot chain line shown in FIG. 1. FIG. 4 is an enlarged perspective view of the periphery of an overload prevention member disposed on the side end regulating plate, where (a) is an inner surface side of the side end regulating plate and (b) is viewed from an outer surface side of the side end regulating plate. It is a figure. These are sectional drawings which abbreviate | omit and show a part of paper feed cassette explaining operation | movement of the overloading prevention member at the time of sheet material filling. FIG. 5 is a cross-sectional view showing a part of the sheet feeding cassette omitted for explaining the posture (basic posture) taken by the overloading prevention member when the height of the loaded sheet material is equal to or less than the maximum stacking position. FIG. 6 is a cross-sectional view showing a part of the sheet feeding cassette for omitting a posture (retracting posture) taken by the overloading prevention member when the height of the stacked sheet material exceeds the maximum stacking position. FIG. 4 is a schematic perspective view when a sheet feeding cassette on which sheet materials are overloaded is mounted on the image forming apparatus main body. These are sectional views of the rear end regulating plate of the conventional paper feed cassette proposed in Patent Document 1. These are the schematic diagrams which expand and show a part of the conventional paper feed cassette proposed by patent document 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed cassette 2 Bottom wall of paper feed cassette 3, 4 Side wall of paper feed cassette 5 Bottom raising member 8, 9 Side end regulating plate 11, 12 Overload prevention member 11a, 12a Short piece of overload prevention member 11b, 12b Overload Long piece of prevention member 11c, 12c Rotating shaft of overload prevention member S Sheet material

Claims (3)

A sheet material filling space for loading and filling the sheet material in an area of the same size as the sheet material;
A regulating plate that defines the range of the sheet material filling space in the width direction of the sheet feeding cassette;
An L-shaped movable member provided above the maximum stacking position of the sheet material of the regulation plate,
When the height of the sheet material stacked in the sheet material filling space is equal to or less than the maximum stacking position, one piece of the movable member projects horizontally into the sheet material filling space, and the other piece Take a basic posture along the outer surface of the restriction plate,
When the height of the sheet material stacked in the sheet material filling space exceeds the maximum stacking position, one piece comes into contact with the sheet material and retreats from the sheet material filling space, and the other piece is the sheet. A paper feed cassette characterized in that it takes a retracted position protruding outside the material filling space.   The sheet feeding cassette according to claim 1, wherein when the sheet material is filled, the movable member can take a retracted position by being pushed down by the sheet material on which one piece falls.   3. An image forming apparatus in which the paper feed cassette according to claim 1 is detachably attached to the main body, and the sheet material is overloaded depending on whether the movable member is in contact with the other piece when the paper feed cassette is attached. An image forming apparatus, comprising: an erroneous mounting preventing unit that prevents erroneous mounting of the paper feed cassette.

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