JP2005145706A - Paper feeding cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the breakage of a lock piece provided on a cursor due to pressure of paper bundle which the cursor receives when a paper feeding cassette is vigorously inserted in an image forming device. <P>SOLUTION: A rack 12 is provided at an upstream portion in a paper feeding direction on an inside bottom surface of a cassette frame 10. The cursor 20 positioning paper P is attached on the rack 12. The lock piece 30 engaging with the lack 12 and locking movement of the cursor 20 is installed to the cursor 20. On a bottom surface of the lock piece 30, a plurality of teeth 32 meshed with the lack 12 and projecting downward is provided. In the lock piece 30, a protrusion 33 is provided outside of a tooth 32a at the farthest position from the paper P of the teeth 32 of the lock piece 30. When the lock piece 30 is meshed with the rack 12, a bottom surface 33a of the protrusion 33 abuts on tips of teeth 13 of the lack 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a paper feed cassette used for stocking a large number of sheets to be supplied to an apparatus in advance.

  The paper feed cassette is used for feeding cut paper or the like in an image forming apparatus represented by a copying machine or a printer. Many paper feeders in an image forming apparatus stock a large number of papers before printing in a paper feed cassette and separate and feed the papers one by one from the uppermost layer of papers stacked in the cassette.

  Some paper cassettes are provided with a cursor. The cursor is movable along a rail provided in the paper feed cassette, and contacts the side surface of the paper stack stacked in the cassette to position the paper. As a result, the paper does not move from a predetermined position, and stable paper feeding can be performed. Examples of such paper feed cassettes can be found in US Pat.

Each of the paper feed cassettes described in Patent Documents 1 and 2 is provided with a sheet regulating means or a paper position regulating member corresponding to the cursor. A lock lever for locking the movement of these cursors is provided. The cursor is locked by engaging the teeth (claws) provided on the locking piece with the racks (recesses) provided on the cassette frame.
Japanese Unexamined Patent Publication No. 2000-219328 (page 4, FIG. 1) JP 2001-187642 A (page 4-5, FIG. 2)

  Here, when the user vigorously inserts the paper feed cassette into the image forming apparatus, the sheet bundle tends to move toward the cursor due to inertia, and the cursor may receive a great deal of pressure from the sheet bundle. In such a situation, in the case of the lock lever described in Patent Literature 1, since there is only one claw that engages with the recess provided in the cassette frame, a load is applied to one claw by the pressure received by the cursor. This nail may be damaged.

  On the other hand, the lock lever described in Patent Document 2 is provided with a plurality of teeth. Since the cursor and lock lever engage with the cassette frame at their lower part, when the cursor is pressed by the stack of paper, the cursor and lock lever are tilted so that their upper part falls toward the outside of the paper cassette. Tilt. When the lock lever is tilted in this way, a very large force is applied to the tooth farthest from the paper at the tooth portion provided at the bottom of the lock lever. Thereby, there is a high possibility that the teeth are damaged.

  The present invention has been made in view of the above points, and in a paper feeding cassette that stocks a large number of papers, when a user vigorously inserts the paper feeding cassette into the image forming apparatus, the present invention is based on pressing of a paper bundle received by a cursor. Another object of the present invention is to provide a paper feed cassette capable of preventing breakage of a lock piece provided on a cursor.

  In order to solve the above-described problems, the present invention provides a paper feed including a cassette frame for stacking and storing paper, and a cursor for positioning the paper, which is movable along a rail provided on the cassette frame. In the cassette, a rack is formed on an inner bottom surface of the cassette frame, and a lock piece for engaging a plurality of downwardly protruding teeth with the rack is attached to the cursor, and the lock piece has a lock piece tooth. Among them, when a protrusion protruding outside the tooth farthest from the paper is provided and the lock piece is engaged with the rack, the bottom surface of the protrusion comes into contact with the tooth tip of the rack tooth. .

  In addition, the protrusion amount of the protrusion is longer than the length in the cursor movement direction of the tooth tip surface of the rack tooth.

  Further, urging means for urging the lock piece in a direction to engage with the rack is provided.

  According to the configuration of the present invention, a rack is formed on the inner bottom surface of the cassette frame, and a lock piece for engaging a plurality of downwardly protruding teeth with the rack is attached to the cursor. The protrusion of the lock piece that protrudes to the outside of the tooth farthest from the paper is provided, and when the lock piece is engaged with the rack, the bottom surface of the protrusion is in contact with the tooth tip of the rack tooth. Even if the lock piece is about to fall down so that the upper part of the lock piece faces the outside of the sheet cassette, the bottom surface of the protrusion and the tooth tip surface of the rack contact each other. The inclination of the piece can be suppressed. As a result, even when the user vigorously inserts the paper feed cassette into the image forming apparatus and the paper tries to move toward the cursor, all of the load is maximized with respect to the paper of the lock piece. It is possible to disperse to a plurality of teeth without applying to one tooth at a distant position. Therefore, breakage of the lock piece can be prevented. Further, since only the protrusions are provided, the cost of the lock piece is small.

  In addition, since the protrusion amount of the protrusion is longer than the cursor moving direction length of the tooth tip surface of the rack, the paper tries to move toward the cursor, and the pressure by the paper acts on the top of the cursor In addition, the position of the power point can be set at the corner of the tooth tip surface of the rack tooth so that the lock piece does not tilt, and the tilt of the lock piece can be further suppressed. Therefore, it is possible to increase the safety against breakage of the lock piece.

  Further, since the urging means for urging the lock piece in the direction of meshing with the rack is provided, the urging means can automatically move the lock piece to the lock position. When the cursor is moved, the lock of the cursor can be easily released simply by moving the lock piece against the biasing means. Therefore, the cursor can be locked and released with a simple operation.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  First, the outline of the structure of the paper feed cassette of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of a paper feed cassette according to an embodiment of the present invention.

  In FIG. 1, a paper feed cassette 1 is accommodated in a lower part of an image forming apparatus such as a copying machine (not shown). A horizontal ridge 2 provided on a side surface is engaged with a rail inside the image forming apparatus, It is slid horizontally in the direction of arrow A shown in FIG. A panel 3 is provided on the front surface of the paper feed cassette 1, and this panel 3 plays a role of constituting a part of the housing at the lower front surface of the image forming apparatus. The main body of the paper feed cassette 1 is composed of a cassette frame 10. The cassette frame 10 is constituted by a flat box having an open upper surface, and stacks and accommodates sheets from the upper surface direction. Inside the image forming apparatus, an upper portion of the front portion of the paper feed cassette 1 is provided with a paper feed means (not shown), and the paper is supplied in the direction of arrow B shown in FIG.

  A cursor 20 is provided in the upstream portion of the cassette frame 10 in the paper supply direction. The cursor 20 contacts the side surface of the sheet bundle from the upstream side in the sheet supply direction, and positions the sheet so that the downstream end of the sheet is positioned at the sheet feeding position by the sheet feeding unit of the image forming apparatus.

  Next, a detailed configuration around the attachment portion of the cursor 20 in the paper feed cassette 1 will be described with reference to FIGS. FIG. 2 is a perspective view showing the vicinity of the cursor mounting portion of the paper feed cassette, and FIG. 3 is a vertical partial sectional view of the same. 4 is a perspective view of the lock piece shown in FIG. 3 as viewed from below, and FIG. 5 is an enlarged vertical partial cross-sectional view of the lock piece and the tooth portion of the rack shown in FIG. ) Shows a state in which the lock piece and the rack are disengaged, and FIG. 5B shows a state in which the lock piece and the rack are engaged.

  In FIG. 2, a rail 11 and a rack 12 are provided on the inner bottom surface of the cassette frame 10 on the upstream side in the paper supply direction. The rail 11 is provided in parallel with the paper supply direction. One rail 11 is formed on the left and right with respect to the central portion in the paper width direction that is perpendicular to the paper supply direction. The rail 11 engages with the cursor 20 to limit the movement of the cursor 20 in the paper supply direction.

  The rack 12 is provided between the two rails 11 in parallel with the rails 11, that is, in parallel with the movement direction of the cursor 20. The rack 12 is provided with a plurality of teeth 13 formed at a predetermined pitch and projecting upward. The tooth 13 has a sawtooth shape in the vertical direction, and the inner end face of the tooth 13 is vertical (see FIGS. 3 and 5).

  The cursor 20 is disposed above the rack 12 between the two rails 11. The cursor 20 has an L-shaped vertical cross section viewed from the paper width direction, and includes a horizontal portion 21 and a vertical paper abutting portion 22. As shown in FIG. 3, the paper P is stacked above the horizontal portion 21 and inside the paper abutting portion 22, and the cursor 20 moves from the outside to the inside of the paper feed cassette 1, that is, the right side in FIG. 3. The sheet P is positioned by contacting the side surface of the sheet bundle from the left to the left.

  In FIG. 2, horizontal protrusions 23 are provided on the left and right side surfaces of the horizontal portion 21 with respect to the paper supply direction. The two horizontal ridges 23 engage with the two rails 11 of the cassette frame 10. A minute clearance is provided between the horizontal ridge 23 and the rail 11 so that the cursor 20 can be moved smoothly.

  A through-opening 24 is provided in the center of the sheet abutting portion 22 in the sheet width direction. Inside the through-hole 24, a rail 25 extending in the vertical direction is provided. One rail 25 is provided on each side of the central portion in the paper width direction.

  A lock piece 30 that engages with the rack 12 and locks the movement of the cursor 20 is attached to the through hole 24 of the paper abutting portion 22 of the cursor 20. As shown in FIG. 4, a slide guide 31 is provided on the side surface of the lock piece 30. The slide guide 31 has two guides 31a formed at intervals in the vertical direction, and is positioned at an intermediate height between the two guides 31a with a space in the horizontal direction from these guides 31a. And one guide 31b formed in the above. The slide guide 31 engages with the rail 25 so as to sandwich the rail 25 provided inside the through hole 24 between the guide 31a and the guide 31b. Thereby, the lock piece 30 can move in the up-down direction. A minute clearance is provided between the slide guide 31 and the rail 25 so that the lock piece 30 can be moved smoothly.

  As shown in FIGS. 4 and 5, a plurality of downwardly projecting teeth 32 that engage with the rack 12 are provided on the bottom surface of the lock piece 30. The teeth 32 have a sawtooth shape in the vertical cross section, and the outer end surfaces of the teeth 32 are vertical (see FIGS. 3 and 5).

  A protrusion 33 is provided on the bottom of the lock piece 30. The protrusion 33 protrudes to the outside of the tooth 32a that is farthest from the sheet P, that is, to the right in FIGS. As shown in FIG. 5B, when the lock piece 30 is engaged with the rack 12, the bottom surface 33 a of the protrusion 33 comes into contact with the tooth tip of the tooth 13 of the rack 12.

  As a result, even if the lock piece 30 is about to fall down so that the upper part of the lock piece 30 faces the outside of the sheet cassette 1, the bottom surface 33 a of the protrusion 33 and the tip surface 13 a of the tooth 13 of the rack 12 are By abutting, the inclination of the lock piece 30 can be suppressed. Accordingly, even when the user vigorously inserts the paper feed cassette 1 into the image forming apparatus and the paper P tries to move toward the cursor 20, all of the load is transferred to the paper of the lock piece 30. Without being applied to the single tooth 32a located farthest from P, it can be distributed to a plurality of teeth. Therefore, breakage of the lock piece 30 can be prevented. Further, since only the protrusion 33 is provided, the cost of the parts of the lock piece 30 can be reduced.

  In FIG. 5, the protrusion amount of the protrusion 33 with respect to the tooth 32 a is longer than the length of the tooth tip surface 13 a of the tooth 13 of the rack 12 in the moving direction of the cursor 20.

  As a result, when the paper P tries to move toward the cursor 20 and the pressure by the paper P acts on the top of the cursor 20, the position of the force point of the teeth 13 of the rack 12 is set so that the lock piece 30 does not tilt. It can be taken at the corner of the tooth tip surface 13a, and the inclination of the lock piece 30 can be further suppressed. Therefore, it is possible to improve the safety against the breakage of the lock piece 30.

  As shown in FIGS. 2 and 3, a spring 40 as an urging means is attached above the lock piece 30 and between the lock piece 30 and the cursor 20. The spring 40 is constituted by a compression coil spring, and is an urging means for urging the lock piece 30 in a direction to engage with the rack 12. Since the cursor 20 engages with the rail 11 of the cassette frame 10 and can move only in the paper supply direction, and the movement in the vertical direction is restricted, the lock piece 30 is pushed downward by the action of the spring 40. Then, the teeth 32 on the bottom surface of the lock piece 30 mesh with the teeth 13 of the rack 12, and the cursor 20 is locked.

  When the cursor 20 is moved in the direction to release the positioning of the paper P, the lock piece 30 is moved upward after being pushed up by the finger against the spring 40. When the cursor 20 is moved in the direction in which the paper P is positioned, the cursor 20 is moved by the slope action of the teeth 13 of the rack 12 and the teeth 32 of the lock piece 30 without moving the lock piece 30 upward. Is possible.

  Thus, since the spring 40 is provided as an urging means for urging the lock piece 30 in the direction in which the lock piece 30 is engaged with the rack 12, the lock piece 30 is automatically moved to the lock position by the spring 40. Can do. Further, when the cursor 20 is moved, the lock of the cursor 20 can be easily released simply by moving the lock piece 30 against the spring 40. Therefore, the cursor 20 can be locked and released by a simple operation.

  In the above embodiment, the cursor 20 moves in the paper supply direction. However, the cursor 20 may move in the paper width direction perpendicular to the paper supply direction. The spring 40 is not limited to a compression coil spring, and may be replaced with a biasing means such as a leaf spring, rubber, or sponge.

  Although the embodiment of the present invention has been described above, various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used in all paper feeding cassettes that require positioning of paper at an appropriate paper feeding position.

These are the perspective views of the paper feed cassette which concerns on embodiment of this invention. FIG. 5 is a perspective view showing the vicinity of a cursor attachment portion of a paper feed cassette. FIG. 4 is a vertical partial sectional view showing the vicinity of a cursor mounting portion of a paper feed cassette. Fig. 3 is a perspective view of the lock piece shown in Fig. 3 as viewed from below. [Fig. 4] is an enlarged vertical partial cross-sectional view of a lock piece and a rack tooth portion shown in Fig. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feeding cassette 10 Cassette frame 11 Rail 12 Rack 13 Rack tooth 13a Tooth surface 20 Cursor 21 Horizontal part 22 Paper abutting part 24 Through-hole 30 Lock piece 32 Lock piece tooth 33 Protrusion 33a Protrusion bottom 40 Spring

Claims (3)

In a paper feed cassette comprising a cassette frame for storing and storing paper, and a cursor for positioning the paper, which is movable along a rail provided on the cassette frame.
A rack is formed on the inner bottom surface of the cassette frame, and a lock piece for engaging a plurality of downwardly projecting teeth with the rack is attached to the cursor. Protrusions that protrude outside the teeth that are farthest from the paper are provided, and when the lock piece is engaged with the rack, the bottom surface of the protrusions abuts the tooth tips of the rack. Paper cassette.   The paper feed cassette according to claim 1, wherein the protrusion amount of the protrusion is longer than the length of the tooth tip surface of the rack in the cursor movement direction.   The paper feed cassette according to claim 1, further comprising an urging unit that urges the lock piece in a direction to engage with the rack.

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