JPH07291465A - Paper sheet feeding tray - Google Patents

Abstract

PURPOSE:To easily assemble a sheet stacking member in such a condition as swingable but not axially movable relative to the body of a sheet feed tray and heighten the strength of a projection which restricts the motion in the axial direction. CONSTITUTION:A sheet stacking member 41 is supported swingably on the body 60 of a sheet feed tray by shafts 41a, 41b installed protrusively to the left and right, and a projection 51 and a recess 61 are fitted together so that the movement to the left and right is restricted. In assembling, the right-hand shaft 41a is fitted in a bearing 60a, and the member 41 is slid in the direction that the left-hand shaft 41b is fitted in another bearing 60b. When contacted with the left bearing 60b, the member 41 is swung toward the tray body 60, which causes the projection 51 to be fitted in the recess 61. The member 41 is supported slightly apart from the bearing through the action of slopes 51e, 63e on the projection 51 and recess 61. The projection 51 is formed from a wall in a square shape along the member 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feed tray having sheets stacked on its upper surface and having a sheet stacking member swingable in the sheet stacking direction.

[0002]

2. Description of the Related Art Conventionally, this type of paper feed tray has been applied to various devices such as an image forming apparatus such as a laser printer and a word processor. For example, the following is known. That is, the sheets are stacked on the upper surface, and a pair of shafts or bearing holes having an axis extending in the left-right direction are formed on both left and right side walls standing upright on the upper surface at both sides in the sheet conveying direction. And a paper feed tray main body having a bearing hole or a shaft fitted in the shaft or the bearing hole so as to be swingable about the axis and slidable in the axial direction, and formed on the lower surface of the paper stacking member. It is possible to swing the paper stacking member around the axis by being formed on the upper surface of the paper feed tray main body facing the paper stacking member and the convex part or recessed portion and fitted with the projection or the recess. A sheet feeding tray provided with a concave portion or a convex portion that holds the shaft in a non-slidable manner.

When assembling a paper feed tray of this type, first, a pair of shafts or bearing holes formed in the paper stacking member and a pair of bearing holes or shafts formed in the paper feed tray body are mutually formed. Mating. Subsequently, the sheet stacking member is appropriately slid in the axial direction so that the convex portion and the concave portion face each other, and then the sheet stacking member is swung in the direction in which the convex portion and the concave portion approach. Through such an operation, the convex portion and the concave portion can be fitted together.

[0004]

However, when the fitting operation of the convex portion and the concave portion is performed, the convex portion and the concave portion cannot be seen because they are hidden by the lower surface of the sheet stacking member. Therefore, the operator relies on his intuition to slide the sheet stacking member and swing the sheet stacking member in a direction in which the convex portion and the concave portion approach each other at a position where the convex portion and the concave portion are considered to face each other. ing. Therefore, the assembling work of this kind of paper feed tray requires skill, and a beginner had to adjust the sliding position of the paper stacking member many times until the convex portion and the concave portion were fitted.

Further, a sliding operation during the assembling work causes a lateral force to act on the convex portion to damage the convex portion, or when the paper stacking member and the paper feed tray are stored in component units, the convex portion is damaged. The impact force sometimes acted on the toe, and the projection was sometimes damaged. Therefore, according to the present invention, the convex portion and the concave portion can be easily fitted to each other at the time of assembly, and further, the efficiency of the assembling work can be achieved, and the convex portion is not damaged. Was made for the purpose of providing.

[0006]

In order to achieve the above object, the invention according to claim 1 is such that sheets are stacked on the upper surface and right and left are erected at right angles to the upper surface on both sides in the sheet conveying direction. A paper stacking member in which a pair of shafts or bearing holes each having an axis extending in the left-right direction are formed on both side walls, and the shafts or bearing holes can swing about the axis and can slide in the axis direction. A sheet feed tray body having a bearing hole or a shaft fitted to the sheet stacking portion, a convex portion or a concave portion formed on the lower surface of the sheet stacking member, and an upper surface of the sheet feed tray body facing the sheet stacking member, By fitting with the convex portion or the concave portion, the paper sheet stacking member can be swung about the axis line, a concave portion or a convex portion that holds non-slide in the axial direction, in a paper feed tray, The above convex and concave Fitted with each other within approximately a predetermined range in which the sheet stacking member is rocked in accordance with the load of the paper, it is configured to a size which deviates when pivoted beyond its predetermined range,
When the paper stacking member slides in one of the axial directions with the convex portion and the concave portion disengaged from each other, the other shaft and the bearing hole are disengaged from each other, and the paper stacking member is When the side wall of the sheet stacking member slides to the other side in the axial direction and substantially abuts on the paper feed tray body, the tips of the pair of shafts have such a length that the other side shaft and the bearing hole fit. The distance between them and the distance between the pair of bearing holes are set, and when the side wall of the paper stacking member substantially abuts on the paper feed tray, the convex portion and the concave portion cause the rocking of the paper stacking member. Accordingly, it is characterized in that they are formed at predetermined positions which are substantially opposed to each other so that they can be fitted to each other.

According to a second aspect of the present invention, when at least one of the convex portion and the concave portion swings from the predetermined position of the sheet stacking member in a direction in which the convex portion and the concave portion approach each other, The sheet stacking member is provided with an inclined surface that abuts on the other of the concave portion and the convex portion and slides the sheet stacking member in a direction in which the side wall that is in contact with the sheet feeding tray main body separates. The gist of the paper feed tray according to claim 1, wherein the convex portion and the concave portion are fitted by sliding.

Further, the invention according to claim 3 is characterized in that the convex portion comprises a pair of flat plates provided so as to face each other, and a reinforcing plate for connecting between the respective flat plates. The main point is the paper feed tray described in 1.

[0009]

The invention according to claim 1 configured as described above is
It can be assembled as follows. First, the shafts of the paper stacking member and the paper feed tray main body are fitted into the bearing holes, and the paper stacking member is slid to the above one. Then, the other shaft and the bearing hole face each other without being fitted yet. Then, when the sheet stacking member is slid to the other side, the other shaft and the bearing hole are fitted to each other, and the side wall of the sheet stacking member substantially abuts on the paper feed tray body. In this state, the convex portion and the concave portion substantially face each other at a predetermined position where they can be fitted to each other. Then, the convex portion and the concave portion can be fitted only by swinging the sheet stacking member from the predetermined position in a direction in which the convex portion and the concave portion are close to each other.

According to the second aspect of the present invention, at least one of the convex portion and the concave portion has an inclined surface, and when the sheet stacking member is swung in a direction in which the convex portion and the concave portion are close to each other, the inclination is provided. The convex portion and the concave portion are fitted by sliding the sheet stacking member on the surface. Therefore, the side wall of the sheet stacking member is slightly separated from the state where it is substantially in contact with the sheet feed tray main body, and the sheet stacking member smoothly swings without being interfered with by the sheet feed tray.

Further, in the invention according to claim 3, the convex portion includes a pair of flat plates provided so as to face each other, and a reinforcing plate for connecting the flat plates. The convex portion configured in this way has extremely good strength and is not easily damaged even when stress is applied in the sliding direction of the sheet stacking member. For this reason,
It is also possible to favorably prevent impact force from the outside or damage to the convex portion during the assembly work of the paper feed tray. Further, by fitting the convex portion and the concave portion, the position of the sheet stacking member in the left-right direction can be accurately regulated, and the image forming position on the sheet can be made precise.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view schematically showing the configuration of a laser printer 1 of an embodiment to which the inventions described in claims 1 to 3 are applied. As shown in the figure, the laser printer 1 of the present embodiment is
A paper feed tray 3 is detachably provided on the upper surface of the rear portion (left side in the drawing) of the main body cover 2. A sheet feeding roller 4 and a holder 5 that is pressed against the sheet feeding roller 4 are provided in a mounting portion of the sheet feeding tray 3 of the laser printer 1, and sheets P stacked on the sheet feeding tray 3 (FIG. 2). Are conveyed one by one from the topmost one.

The sheets P conveyed one by one by the sheet feed roller 4 are further conveyed by a pair of conveying rollers 6 and sent to a developing unit 9 having a photosensitive drum 7 and a transfer roller 8. The developing unit 9 is further provided with a toner cartridge 11 that holds toner and a developing device 13 to which toner is supplied from the toner cartridge 11, and an image corresponding to the laser beam 19 emitted from the scanner unit 17 is displayed. Formed on the paper P. Further, the paper P ejected from the developing unit 9 is conveyed to a fixing unit 23 having a heating roller 21 and a pressing roller 22, and subsequently ejected to a paper ejection tray 25 via a paper ejection roller 24.

Next, below the developing unit 9, the above-mentioned scanner unit 17 provided with a laser beam generator 30, a lens 31, and a reflecting mirror 32 is arranged, and further, the control board 3 is provided.
3, 35, a power supply unit 37, etc. are arranged. The scanner unit 17 emits laser light 19 according to image data transmitted from an external device such as a computer (not shown). Then, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 7 which is charged in advance by the charger 39 provided in the developing unit 9. Subsequently, the developing device 13 visualizes the latent image with the magnetized powdery toner, and then transfers the toner image onto the sheet P supplied between the photosensitive drum 7 and the transfer roller 8. . Further, the fixing unit 23 applies heat and pressure to the transferred toner image, so that the paper P
The toner image is fixed on.

Next, FIG. 2 is a vertical sectional view showing the structure of the paper feed tray 3, and FIG. 3 (A) is a horizontal sectional view thereof. 2 corresponds to the cross section taken along the line AA of FIG. 3A, and FIG. 3A corresponds to the cross section taken along the line BB of FIG. Also,
FIG. 3B is an enlarged view of the vicinity of the convex portion 51 and the concave portion 61 in FIG.

As shown in FIG. 2, a paper receiving plate 41 as a paper stacking member is provided in the paper feeding tray 3 so as to be swingable about shafts 41a and 41b (FIG. 3) at the upstream end in the paper conveying direction. , Is urged upward (to the right in the figure) by the spring 42. Further, the sheet feeding roller 4 is arranged at the downstream end of the sheet receiving plate 41 in the sheet conveying direction, and is configured as follows. That is, a feed roller 45 that is formed in a D-shaped side cross-section and that includes a contact surface 4a having a circumferential surface that contacts the paper P and a non-contact surface 4b that does not contact the paper P and that rotates integrally with the drive shaft 43. , A paper feed collar 48 that is loosely fitted to the drive shaft 43 and presses the paper P toward the holder 5 by its own weight, and at least the contact surface 4a of the feed roller 45 is a member having a large friction coefficient such as rubber, or paper feed. The collar 48 is made of a slippery member having a friction coefficient significantly smaller than that of rubber. The drive shaft 43 rotates intermittently via a drive motor and a transmission gear mechanism (not shown).

Further, in the vicinity of the downstream end of the paper feed tray 3 in the conveying direction, a holder 5 having a surface on which a separation pad body 5a having a large frictional force is adhered is provided so as to be vertically movable in the radial direction of the paper feed roller 4. The spring 50 urges the paper feed roller 4 in a direction of abutting it. When the non-contact surface 4b of the paper feed roller 4 faces each other, the separation pad body 5a moves the non-contact surface 4b.
The rising position of the holder 5 is regulated by the paper feed collar 48 so as not to abut against b.

The sheet conveying operation by the sheet feeding roller 4 will be described. When a print command is input to the laser printer 1 and a sheet feeding command is output from the control boards 33 and 35,
A drive motor (not shown) operates to move the paper feed roller 4 to the paper P.
One rotation is made in the carrying direction (direction of arrow F in FIG. 2). By this rotation, the uppermost sheet P of the sheets P stacked on the sheet feed tray 3 comes into contact with the contact surface 4a of the sheet feed roller 4, and is pressed and sandwiched between the sheet P and the separation pad body 5a to form only one sheet. It is separated and conveyed in the direction of the conveying roller pair 6. Then, each time the paper P is conveyed, the spring 42 swings the paper receiving plate 41 toward the paper feed roller 4, and the uppermost paper P stacked on the paper receiving plate 41 is fed by the upper surface in the conveying direction. Color 48
Abut.

Next, the shafts 41a and 41b of the paper receiving plate 41
A convex portion 51 is formed on the lower surface of the vicinity of the sheet receiving plate 41.
A concave portion 61 that fits into the convex portion 51 is formed on the upper surface of the sheet feeding tray main body 60 that supports the sheet feeding tray via the shafts 41a and 41b. The concave portion 61 is composed of a groove portion 62 of the paper feed tray main body 60 and a fitting piece 63 projectingly provided around the groove portion 62. The groove portion 62 is formed long in the swinging direction of the convex portion 51 of the sheet receiving plate 41 in the sheet stacking state, and is formed on both left and right sides of the groove portion 62 (both sides in the direction orthogonal to the swinging direction, that is, the shaft 41).
side pieces 63a, 63 of fitting pieces formed on a, 41b side)
b also extends long in the swing direction. The convex portion 51 has a pair of flat plates 51a and 51b extending in the swinging direction on the left and right sides similarly to the above, and a pair of reinforcing plates 51c and 51b connecting the flat plates 51a and 51b at both ends in the swinging direction.
2 (FIG. 2), it is formed in a square shape parallel to the lower surface of the sheet receiving plate 41, that is, a frame shape.

The dimension between the outer side surfaces of the pair of flat plates 51a and 51b is formed to be substantially the same as the dimension between the inner side surfaces of the side pieces 63a and 63b. Therefore, by fitting the convex portion 51 and the concave portion 61, the pair of flat plates 51a and 51b are separated from each other by the side pieces 63a and 63.
While being in contact with the inner side surface of b, it can be swung in the above-mentioned swing direction, and the movement of the sheet receiving plate 41 in the left-right direction, that is, the direction orthogonal to the sheet transport direction is prohibited.

Further, as can be seen from FIG. 2, the paper receiving plate 41 rocks beyond a predetermined range in which the paper receiving plate 41 rocks in accordance with the stacking amount of the paper P (for example, beyond the arrangement position of the paper feed roller 4). At this time, the projection 51 and the recess 61 are disengaged from each other. On the other hand, the above-mentioned shafts 41a and 41b are provided on both upper and lower sides of the sheet receiving plate 41 at right angles on both sides in the sheet conveying direction.
From the paper feed tray main body 6
Bearings 6 as bearing holes into which the shafts 41a and 41b are fitted so as to be swingable and slidable in the axial direction on both left and right side walls of 0.
0a and 60b are formed respectively.

Dimension L between the tips of the pair of shafts 41a and 41b
1 (FIG. 3) is formed larger than the dimension L2 between the bearing portions 60a and 60b. The dimension L3 between the outer surface of the right side wall 41d and the tip of the left shaft 41b is formed to be substantially the same as or slightly smaller than L2. When the convex portion 51 and the concave portion 61 are engaged with each other, a predetermined space a is provided between the right side wall 41d of the sheet receiving plate 41 and the bearing portion 60a, and a predetermined gap a is provided between the left side wall 41e and the bearing portion 60b. A predetermined space b is opened. The length of the shaft 41b is shorter than the distance a.

Further, as shown in FIG.
Inclined surfaces 51e and 63e are formed by chamfering the outer edges of a and 51b and the inner edges of the side pieces 63a and 63b. Then, the inclined surfaces 51e, 63
The sum c of the widths of e in the left-right direction is substantially the same as or larger than the predetermined interval b.

The dimension L4 between the left bearing portion 60b and the upper end of the inclined surface of the left side piece 63b is almost the same as the dimension L5 between the outer surface of the left side wall 41e and the downstream side of the inclined surface of the left flat plate 51a. It is smaller than that by the difference between c and b. To assemble the paper feed tray 3 configured in this way, refer to FIG.
The sheet receiving plate 41 to the sheet feeding tray main body 60 as
First, as shown in FIG. 5, the right shaft 41a is fitted into the bearing portion 60a in a state in which the sheet is placed at a steeper angle than the normal sheet stacking state (FIG. 2), and the sheet receiving plate 41 is mounted on the right side wall 41d. When it is slid in the direction close to 60a, L2 <L3 or L2 ≈ L3, so the left shaft 41b and the bearing portion 60
Opposite b is not yet fitted (shown by a chain double-dashed line in FIG. 5). In this state, as shown by the chain double-dashed line in FIG.
Since the sheet receiving plate 41 stands at a steep angle, the convex portion 51 is located above the concave portion 61 and is not yet fitted.

Then, when the sheet receiving plate 41 is slid in the direction of the left shaft 41b, the shaft 41b and the bearing portion 60b are fitted together. When the left side wall 41e slides until it comes into contact with the bearing portion 60b, the convex portion 51 is positioned substantially above the concave portion 61 so as to face it. From this state (shown by the chain double-dashed line in FIG. 4), the sheet receiving plate 41 is moved to the position of the sheet stacking state in FIG. 2 by the shafts 41a and 41b.
When swinging around, L4 <L5 or L4 ≒ L
Therefore, the convex portion 51 and the concave portion 61 are close to each other and abut on the inclined surfaces 63e and 51e. Further, the paper receiving plate 41 swings in the same direction, so that the inclined surfaces 63e, 51
The convex portion 51 fits into the concave portion 61 while the sheet receiving plate 41 slides toward the right shaft 41a by the action of e. As a result, the sheet receiving plate 41 is swingably supported around the shafts 41a and 41b with a gap b between the left side wall 41e and the bearing portion 60b, and is movable in the directions of the shafts 41a and 41b. prohibited. After that, the paper feed roller 4 is assembled to the paper feed tray main body 60 together with the holder 5 and the shaft 43.

As described above, in the sheet feeding tray 3 of this embodiment, the sheet receiving plate 41 is made to be convex by simply swinging the sheet receiving plate 41 toward the sheet feeding tray main body 60 while keeping the left side wall 41e in contact with the end face of the bearing portion 60b. The part 51 and the recess 61 can be fitted together. That is, the work of fitting the convex portion 51 and the concave portion 61 hidden on the lower surface of the paper receiving plate 41 can be easily performed without relying on the intuition. Therefore, the paper feed tray 3
The assembly work of can be streamlined, and even beginners can easily perform it.

Also, in this embodiment, the inclined surfaces 63e, 51
The sheet receiving plate 41 is moved to the left side wall 41e
Is slid in a direction away from the bearing portion 60b, a predetermined distance b can be provided between the left side wall 41e and the bearing portion 60b. In this way, by opening the predetermined intervals a and b between the left and right side walls 41d and 41e of the paper receiving plate 41 and the paper feed tray main body 60, the rocking of the paper receiving plate 41 can be made sufficiently smooth. it can.

Further, in this embodiment, since the convex portion 51 is formed in a square shape in cross section, it has extremely good strength. Therefore, even if a stress is applied to the sheet receiving plate 41 in the left-right direction, the convex portion 51 is not easily damaged. Therefore, it is possible to favorably prevent the convex portion 51 from being damaged during the assembling work of the paper feed tray 3, and the assembling work can be made easier and more efficient. Further, the paper receiving plate 41 is attached to the left and right side walls 4
If the left and right side walls 41d and 41e are deformed when the left and right positions are restricted by only 1d and 41e, the sheet receiving plate 4 is deformed.
However, in this embodiment, the convex portion 51 having sufficient strength regulates the lateral position of the sheet receiving plate 41, so that even if the side walls 41d and 41e are deformed, the image forming position on the sheet is changed. Can be kept accurate.

The present invention is not limited to the above embodiments, but can be carried out in various modes without departing from the scope of the present invention. For example, in the above embodiment,
Shafts 41a and 41b are provided on both left and right sides of the sheet receiving plate 41 so that the sheet feeding tray main body 60 has a bearing portion 60 corresponding thereto.
Although a and 60b are formed, a bearing portion is formed on one side or both left and right sides of the sheet receiving plate 41, and the sheet tray main body 60 is formed.
A shaft corresponding to it may be provided in a protruding manner. Further, the paper feed tray main body 60 is provided with the convex portion 51, and the paper receiving plate 41 is provided with the concave portion 6.
1 may be provided.

[0030]

As described above in detail, according to the first aspect of the invention, the sheet stacking member is swung to the other side so that the side wall of the sheet stacking member is brought into contact with the main body of the sheet feeding tray, and then the sheet is continuously fed. The protrusion and the recess can be fitted only by swinging the stacking member in a direction in which the protrusion and the recess approach each other. Therefore, the work of fitting the convex portion and the concave portion at the time of assembling can be facilitated, and as a result, the assembling work of the paper feed tray can be streamlined and can be easily performed by a beginner.

According to the second aspect of the present invention, the side wall of the sheet stacking member is slightly separated from the state in which the side wall of the sheet stacking member is substantially in contact with the sheet feeding tray main body, and the swinging of the sheet stacking member can be made sufficiently smooth. Further, in the invention according to claim 3, the convex portion has extremely good strength and is not easily broken even if stress is applied in the sliding direction of the sheet stacking member. Therefore, it is possible to favorably prevent breakage of the convex portion during the assembly work of the paper feed tray. Therefore, in addition to the effect of the first aspect of the invention, the work of assembling the paper feed tray can be further facilitated and streamlined. Further, the right and left positions of the sheet stacking member are accurately regulated, and the image forming position on the sheet can be accurately maintained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a configuration of a laser printer according to an embodiment.

FIG. 2 is a vertical cross-sectional view showing a configuration of a paper feed tray of the laser printer of the embodiment.

FIG. 3 is a cross-sectional view showing the configuration of the paper feed tray of the laser printer of the embodiment.

FIG. 4 is a vertical cross-sectional view illustrating a method of assembling the paper feed tray.

FIG. 5 is a transverse cross-sectional view illustrating a method of assembling the paper feed tray.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser printer 3 ... Paper feed tray 41 ... Paper receiving plate 41a, 41b ... Shaft 41d ... Right side wall 41e ... Left side wall 42 ... Spring 51 ... Convex part 51a, 51b ... Flat plate 51c, 51d ... Reinforcing plate 51e, 63e ... Inclination Surface 60 ... Paper feed tray body 60a, 60b ... Bearing portion 61 ... Recessed portion 62 ... Groove portion 63 ... Fitting piece

Claims (3)

[Claims] 1. A sheet is stacked on the upper surface, and a pair of shafts or bearing holes having an axis line extending in the left-right direction is formed in both left and right side walls which are erected at right angles to the upper surface on both sides in the sheet conveying direction. A paper stacking member, a paper feed tray body having a bearing hole or shaft that fits in the shaft or bearing hole so as to be swingable about the axis and slidable in the axial direction, and the paper stacking member Is formed on the lower surface of the paper feed tray main body facing the paper stacking member, and is fitted to the projection or the recess so that the paper stacking member is centered on the axis line. In a paper feed tray having a concave portion or a convex portion that is swingable in the axial direction and is held so as not to be slidable in the axial direction, the convex portion and the concave portion are oscillated by the sheet stacking member according to the amount of sheets stacked. Within a certain range of movement The sheet stacking members are fitted to each other and are sized so that they are disengaged when swung beyond a predetermined range, and the sheet stacking member slides in one of the axial directions in a state where the protrusions and the recesses are disengaged. At this time, the other shaft is disengaged from the bearing hole, the paper stacking member slides to the other side in the axial direction, and the side wall of the paper stacking member substantially contacts the paper feed tray body. At this time, the distance between the tips of the pair of shafts and the distance between the pair of bearing holes are set to the length at which the other shaft and the bearing hole are fitted, and the side wall of the paper stacking member is set to the paper feed tray. A sheet feeding tray, wherein the convex portion and the concave portion are formed at predetermined positions that are substantially opposed to each other so that they can be fitted to each other when the sheet stacking member is swung, when they are substantially in contact with each other. 2. When at least one of the convex portion or the concave portion swings from the predetermined position in the direction in which the convex portion and the concave portion are close to each other, the at least one of the convex portion and the concave portion is in the other of the concave portion and the convex portion. The sheet stacking member has an inclined surface that slides in the direction in which the side wall that is in contact with the sheet feeding tray main body moves away from the sheet stacking member. The paper feed tray according to claim 1, wherein the concave portion is fitted with the concave portion. 3. The paper feed tray according to claim 1, wherein the convex portion includes a pair of flat plates provided so as to face each other, and a reinforcing plate connecting the flat plates.