JP3518612B2 - Power transmission mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission mechanism between a main body provided with a drive motor and another unit not provided with a drive motor, and more particularly to a copying machine and the like. The present invention relates to a power transmission mechanism suitable when the image forming apparatus main body and the sheet feeding device are separated from each other and a driving motor is not provided in the sheet feeding device. 2. Description of the Related Art Generally, a power transmission mechanism of this kind includes a gear 31 provided on the main body of an image forming apparatus and rotated by a drive motor on the main body, and a drive motor, as shown in FIG. Gear 3 provided on the side of the paper feeder not provided
2, the shafts of a gear 33 that is also provided on the paper feeding device side and meshes with the gear 32 are configured substantially in a straight line, and when the paper feeding device is assembled on the main body side, the gears 31 and 32 are formed. It is configured to engage. However, in such a configuration, the gear 31 and the gear 32 are often bite too much or not enough, so that a regulating plate for keeping the distance between the gear 31 and the gear 32 constant is necessary. In this case, the restriction plate must be screwed, so that the user cannot easily assemble the sheet feeding device to the main body. Therefore, in the conventional mechanism, for example, as shown in FIG. 8, the angle between the line connecting the shafts of the gears 31 and 33 and the center gear 32 is set to about 35 °, and as shown in FIG. Is known in which the gear 32 is biased in the direction of pressure contact with the gear 31 by a spring 34 so as to obtain a stable bite (for example, Japanese Patent Laid-Open No. 58-789).
No. 28). However, in the above-described conventional mechanism, since the gear 31 on the main body side and the gear 32 on the paper feeder side are pressed by the spring 34, the gear 31, If there is a variation in the gear shape of the gear 32, there is a problem that an unusual sound is generated, and the biting force is transmitted to the drive motor via the shaft of the gear 31 on the main body side to increase the power load. Further, a special control is required to control and synchronize the paper feeding speeds of the main body and the paper feeding device.
Also, if the opening for accommodating the gear 32 on the paper feeder side in the main body is always open, a finger may be erroneously inserted, which is dangerous. The present invention has been made in consideration of the above-described conventional problems, and has as its object to provide a power transmission mechanism capable of preventing abnormal noise and reducing a power load. In order to achieve the above object, a first means is constructed such that a main body and a separate unit can be assembled, and the main body has a first gear rotated by a drive motor. In a power transmission mechanism in which the separate unit has a second gear to which rotation of the first gear is transmitted, a bracket that supports the second gear so as to be rotatable in the direction of the first gear is provided. A leaf spring provided on the separate unit and abutting against the bracket to press the second gear against the first gear is provided on the main body, and is provided coaxially with the first and second gears. A member that regulates a distance between the first and second gears when the leaf spring contacts the bracket and presses the second gear against the first gear; Protrudes the housing of another unit
And the second gear is provided therein.
An opening for receiving is formed in the main body, and the opening is formed in the main body.
A cover that can be opened and closed is provided.
If the unit is not assembled, close the opening and
Opening and closing the opening when the body and another unit are assembled
A mechanism is provided, and the opening and closing mechanism is provided in a separate unit.
A positioning pin, and the positioning pin is insertable;
Partially covered by the cover in the closed state, the positioning
When the pin is gradually inserted, open the cover gradually
And the cover in the closed position.
Energizes in the closing direction and the positioning pin
The cover is gradually opened and the cover is gradually opened,
A spring member for urging the cover in the opening direction when the pressure exceeds
It is characterized by having . According to the first means, the main body and the separate unit are assembled.
To accommodate the second gear when not engaged
The opening formed in the main body is closed by the cover
When the positioning pin is gradually inserted into the positioning hole,
As the bar is biased in the opening direction, the wrong finger
Insertion can be prevented, and the main unit and another unit
The cover is opened by the positioning pin when assembled.
And the second gear on another unit collides with the cover
Can be prevented. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a main part showing an embodiment of a power transmission mechanism according to the present invention, FIG. 2 is a perspective view of a main part showing an open / close state of a cover of FIG. 1, and FIG. FIG. 4 is an exploded perspective view showing the pitch determining member of FIG. In FIGS. 1 to 3, the main body 1 and the paper feeder 10 are formed separately from each other, so that the main body 1 can be assembled on the paper feeder 2, and the main body 1 is provided with a drive motor. In addition, the sheet feeding device 10 is not provided with a drive motor. A gear 2 for transmitting power to the gear 9 on the paper feeder 2 side is provided in the main body 1, and the gear 2 is a transmission belt 21.
Is connected to a drive motor (not shown). A gear 9 on the side of the paper feeder 2 and a bracket 7 for supporting the gear 9 are arranged so as to protrude upward from its housing. Is formed with a rectangular opening 1a for accommodating the gear 9 and the bracket 7 therein when assembled. Further, the main body 1 and the paper feeding device 2 respectively
A circular positioning hole 11 for positioning the teeth of the gears 2 and 9 in the horizontal direction and a reference pin 6 are provided, and the upper end of the reference pin 6 is formed by a substantially conical tapered portion 6a. In addition,
In order to position the teeth of the gears 2 and 9 in the horizontal direction, at least one other positioning member (not shown) is provided in addition to the positioning hole 11 and the reference pin 6. The body 1 has a cover 3 whose one end is rotatable in a horizontal direction around a shaft 3a for opening and closing the opening 1a and the positioning hole 11 as shown by a solid line and a broken line in FIG. The main body 1 contacts the section 7a of the bracket 7 and
A leaf spring 4 is provided for meshing the gear 2 on the paper side with the gear 9 on the paper feeder 10 side. The cover 3 is urged in the closing direction by the coil spring 5. In this closed state, the tapered portion 6a of the reference pin 6 is inserted so as to completely close the opening 1a and close approximately one third of the positioning hole 11. It is positioned by a stopper (not shown) as much as possible. The coil spring 5 is disposed at a position where its axis is slightly displaced from the rotation axis 3 a of the cover 3. Therefore, the cover 3 is gradually opened against the urging force of the coil spring 5, and the axis of the coil spring 5 is rotated by the rotation axis of the cover 3. When passing over 3a, the cover 3 is opened by the urging force of the coil spring 5. The leaf spring 4 on the main body 1 side is formed with a section 4a that comes into contact with the section 7a of the bracket 7, and the bracket 7 on the paper feeder 10 side comes into contact with the section 7a of the leaf spring 4 when the section 7a comes into contact with the section 7a. It is configured to rotate in the direction of the first gear 2. In addition, as shown in FIG.
Reference numeral 9 denotes a state in which the main body 1 and the paper feeding device 10 are assembled.
The angle between the line connecting the shafts of the gear 2 and the gear 8 and the gear 9 is about 35 °. A gear 9 and a feeding gear 8 meshing with the gear 9 are rotatably mounted on the bracket 7 and are provided coaxially with the gear 2 on the main body 1 as shown in detail in FIG. Pitch determining member 12 that can abut on the pitch determining member 12a
b is attached. The assembling operation of such a configuration will be described. First, in a state where the main body 1 and the sheet feeding device 10 are not assembled, the cover 3 is closed to cover the opening 1a and the like.
Therefore, it is possible to prevent an accident such as accidentally inserting a finger into the opening 1a. On the other hand, when assembling the main body 1 and the paper feeder 10, the tapered portion 6a of the reference pin 6
The main body 1 is positioned so as to be inserted into the paper feeder 1.
When placed on the main unit 1, the cover 3 is opened and the gear 9 and the bracket 7 on the paper feeder 10 side can be inserted into the main body 1. When the main body 1 is completely placed on the paper feeder 10, the gears 2 and 9 mesh with each other. However, the section 4a of the leaf spring 4 on the main body 1 is fixed to the bracket on the paper feeder 10 side. 7, the gear 9 is pressed against the gear 2, and the pitch determining members 12a, 12b abut to prevent excessive pressing. Therefore, stable biting of the gears 2 and 9 can be obtained, so that abnormal noise can be prevented and the power load can be reduced. Next, a reference example will be described with reference to FIG.
In this embodiment, instead of the gears 2 and 9 as a mechanism for transmitting between the main body 1 and the paper feeder 10, a toothed pulley 13 is used.
Is provided on the body 1 side and the toothed pulley 13
A toothed belt 14 is provided on the paper feeder 10 side. The toothed belt 14 protrudes above the paper feeding device 10 and is wound around idle pulleys 15a to 15c so as to mesh with the toothed pulley 13 through the opening 1a in a state where the main body 1 and the paper feeding device 10 are assembled. Have been. Note that the two idle pulleys 15a and 15b protrude above the paper feeder 10, and the idle pulley 15c is provided inside the paper feeder 10. The toothed belt 14 is pressed by a roller 18 at the tip of an arm 16 urged by a spring 17 so that the engagement with the toothed pulley 13 is constant. The arm 16 has a rear end rotatably mounted in the paper feeding device 10, one end of a spring 17 fixed substantially at the center, and the other end of the spring 17 fixed inside the paper feeding device 10. . Therefore, in this embodiment as well, the toothed belt 14 is pressed by the urging force of the spring 17 and the like, so that the meshing between the toothed belt 14 and the toothed pulley 13 can be made constant. Power noise can be reduced while preventing abnormal noise. In this reference example, the toothed belt 1 is used.
A chain and a sprocket may be used in place of the pulley 4 and the toothed pulley 13, respectively. In the second embodiment, as shown in FIG. 5, an opening / closing mechanism such as a spring 5 for opening / closing the cover 3 is mounted so as to stand upright along the inner surface of the side wall of the main body 1. It is suitable when the space in 1 is narrow. Further, in the first and second embodiments, when the tapered portion 6a of the reference pin 6 having a relatively small diameter is inserted into the positioning hole 11, the cover 3 completely opens the opening 1a. An opening and closing mechanism using a spring can be used. FIG. 6 shows an example in which the spring 5a is disposed on the rotating shaft 3 of the cover 3, and the spring 5b is the spring 5a.
Are provided on the positioning hole 11 side with their axes shifted in parallel to urge the cover 3 in the closing direction. In this configuration, when the tapered portion 6a of the reference pin 6 is gradually inserted into the positioning hole 11 with the cover 3 closed, the cover 3 is gradually opened against the urging force of the spring 5b, and the spring 5b is opened. When passing through the axis of the spring 5a, the cover 3 is opened by a so-called snap action by the urging force of the spring 5b. Therefore, when the reference pin 6 is inserted into the positioning hole 11, the cover 3 completely opens the opening 1a, so that the gear 9 and the toothed belt 14 can be prevented from colliding with the cover 3, and the cover 3 can be closed. In the state, the finger is accidentally opened 1
a can be prevented from being inserted. As described above, according to the present invention configured as described above, the following effects can be obtained. That is, according to the first aspect of the present invention,
If the main unit and another unit are not assembled,
The opening formed in the main body to accommodate the gear inside
Closed by cover, positioning pin is positioned
The cover is urged in the opening direction when it is gradually inserted into the hole.
With, it is possible to prevent the wrong finger from being inserted into the opening,
And when the main unit and another unit are assembled,
The cover is opened by the female pin and the second
Can be prevented from colliding with the cover. [0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a main part showing an embodiment of a power transmission mechanism according to the present invention. FIG. 2 is a perspective view of a main part showing an open / closed state of a cover of FIG. 1; FIG. 3 is a side view showing a positional relationship between the main body of FIG. 1 and a sheet feeding device. FIG. 4 is an exploded perspective view showing the pitch determining member of FIG. FIG. 5 is a side view showing a power transmission mechanism of a reference example. FIG. 6 is a plan view showing a modification of the cover opening / closing mechanism. FIG. 7 is a side view showing a general power transmission mechanism. FIG. 8 is a side view showing a conventional power transmission mechanism. FIG. 9 is a side view showing a modified example of the power transmission mechanism of FIG. [Description of Signs] 1 Main body 1a Openings 2, 8, 9 Gear 3 Cover 4 Leaf spring 5, 5a, 5b, 17 Coil spring 6 Reference pin 6a Tapered portion 7 Bracket 7a Section 10 Paper feeder 13 Toothed pulley 14 Toothed belt 15a-15c Idling pulley

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 1/00-1/26 G03G 15/00 B65H 1/00-3/68

Claims (1)

(57) [Claim 1] A main body and a separate unit are configured to be assembled, and the main body has a first gear rotated by a drive motor, and the separate unit is connected to the first gear. A power transmission mechanism having a second gear to which rotation of the first gear is transmitted, a bracket for rotatably supporting the second gear in the direction of the first gear is provided in the separate unit, and A leaf spring for contacting and pressing the second gear against the first gear is provided on the main body, and is provided coaxially with the first and second gears. the first when pressed against the second gear to the first gear includes a member for regulating the distance between the second gear, as it said second gear protrudes a housing separate units Setting
To accommodate the second gear inside
Opening is formed in the main body, and the opening can be opened and closed in the main body.
Provide a cover, the cover is assembled with the main unit and another unit
If it is not locked, close the opening and separate it from the main unit.
An opening / closing mechanism that opens the opening when the cover is assembled. The opening / closing mechanism includes a positioning pin provided in another unit, and the cover in a closed state in which the positioning pin can be inserted.
-Partially covered with the positioning pin
Is provided on the body so that the cover is gradually opened when
The cover is biased in the closing direction when the cover is closed,
Is gradually inserted into the positioning hole and the cover gradually
The cover in the opening direction when it exceeds the specified position.
A power transmission mechanism , comprising: a biasing spring member .