JP3592459B2 - Open / close type power transmission device in image forming apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an openable power transmission device that is openably and closably mounted on an apparatus body of an image forming apparatus such as a copying machine or a printer.
[0002]
[Prior art]
2. Description of the Related Art Many image forming apparatuses such as copiers, printers, and facsimile apparatuses are provided with a cover such as an openable / closable cover and a feeder cover that can be opened and closed on the apparatus main body side. A power transmission mechanism that engages with the power transmission mechanism on the apparatus main body when the cover is closed is disposed at a predetermined position on the cover.
[0003]
Japanese Utility Model Laid-Open No. 5-51841 is one of the known techniques having the cover. This "facsimile device cover mounting structure" is a device in which a feeder cover, which is an opening / closing cover, is supported by a cantilever pin on the device main body, and a feed roller, a feed roller, an extract roller, a press roller, etc. of the device main body are provided on the feeder cover side. Is arranged. Further, a driving pulley is provided at the pin support point, and the driving pulley is connected to the feeding roller side by a timing belt.
[0004]
[Problems to be solved by the invention]
In the cover mounting structure disclosed in Japanese Utility Model Laid-Open No. 5-51841, since one of the power transmission mechanisms is disposed at the support point as described above, the power transmission is not affected by opening and closing the cover. However, arranging the power transmission mechanism at the support point requires many parts such as a belt, a driving pulley, a gear, and a tension pulley, thus complicating the structure and increasing the cost. Therefore, there is a demand for a switchable power transmission device that has a simple structure and does not affect the power transmission mechanism.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above demands, and has an object to provide an opening / closing power transmission device in an image forming apparatus that has a simple and inexpensive structure and that reliably transmits power. I do.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a power transmission mechanism, such as a gear and a roller, which mutually engages with a predetermined position of both an apparatus main body and an opening / closing cover supported by a cantilever pin so as to be able to open and close. The open / close type power transmission device provided, wherein the support point of the open / close cover is in a common normal direction when the gears mesh with each other, and in a direction of the common normal acting on a center point of the gear on the open / close cover side. An opening / closing power transmission device in an image forming apparatus , wherein the opening / closing cover is arranged on the opposite side to the meshing point with the pressure direction line interposed therebetween, and the opening / closing cover is urged in a direction pressed against the apparatus main body when closed. Make up.
[0007]
According to another aspect of the present invention, the roller is a spacer roller that is disposed coaxially with the gear and has an outer diameter equal to a pitch circle of the gear.
[0008]
According to a third aspect of the present invention, the roller is a separation roller and a feed roller which are arranged in connection with the gear.
[0009]
The opening / closing type power transmission device according to claim 4, wherein the power transmission mechanism such as the gears and the rollers disposed on the opening / closing cover side is connected to the power transmission mechanisms such as the gears and the rollers on the device body side. A spring member for pressing is additionally provided.
[0010]
According to a fifth aspect of the present invention, the opening / closing type power transmission device is characterized in that a transport roller that engages with a transport roller on the device body side is provided on the opening / closing cover side.
[0011]
The opening / closing power transmission device according to claim 6, wherein one of the transport rollers is disposed at the support point of the opening / closing cover.
[0012]
When the open / close cover is closed, the gear on the open / close cover meshes with the gear on the apparatus body side. The gear on the opening / closing cover side is pressed in the common normal direction by the driving force on the apparatus main body side, and a force is generated in a direction away from each other. However, this force becomes an operating force of a moment for pushing the open / close cover toward the apparatus main body with respect to the support point of the open / close cover, and the open / close cover is constantly pressed against the apparatus main body due to the moment. That is, when the opening / closing cover is closed, it is urged in a direction pressed against the apparatus body. Therefore, the opening / closing cover is securely combined with the apparatus main body, and power is reliably transmitted to the power transmission mechanism on the opening / closing cover side.
[0013]
Further, by arranging a spacer roller having the same diameter as the pitch circle of the gear on the same axis as the gear, the positioning between the gears when the opening / closing cover is closed is accurately performed.
[0014]
In addition, by providing a spring member to the power transmission mechanism on the opening / closing cover side, the gears mesh with each other more smoothly.
[0015]
Further, the present invention is also applied to a document separating device of an image forming apparatus and a roller of a document conveying device, and can be applied to a wide range of places.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an opening / closing type power transmission device of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a drive gear 4 is disposed at a predetermined position on the apparatus main body 3 side of the image forming apparatus, and a support point 2 of an opening / closing cover 1 is pivotally mounted. The opening / closing cover 1 is cantilevered so as to be openable and closable about a support point 2. On the other hand, a driven gear 5 is pivotally supported on the opening / closing cover 1 at a predetermined position by a bearing 6 or the like. Note that the driving gear 4 and the driven gear 5 are arranged at positions where they can mesh with each other with the open / close cover 1 closed. Further, a spring member 7 for pressing the driven gear 5 toward the driving gear 4 is held and attached to the opening / closing cover.
[0017]
As shown in FIG. 1, when the driving gear 4 and the driven gear 5 mesh with each other, a driving force acts on the meshing point (referred to as point P) along the common normal direction. This driving force acts on the center point of the driven gear 5 as a force in the direction of the arrow (referred to as the pressure angle direction). The support point 2 is disposed at a position slightly separated from the center point of the driven gear 5 in the pressure angle direction, and is disposed on the opposite side of the mesh point P with respect to the pressure angle direction line 8 in the pressure angle direction. That is, a perpendicular line 9 from the support point 2 toward the apparatus main body 3 can be hung from the pressure angle direction line 8.
[0018]
With the above structure, assuming that the force acting on the center point of the driven gear 5 is F, a clockwise moment of F × R (R is the length of the perpendicular 9) acts on the support point 2. The clockwise moment acts as a rotational moment that presses the opening / closing cover 1 toward the apparatus main body 3, thereby making the engagement between the driving gear 4 and the driven gear 5 more reliable.
As described above, in the present invention, by arranging the support point 2 of the opening / closing cover 1 at the above-mentioned position, the engagement of the power position mechanism on the apparatus body 3 side with the opening / closing cover 1 side can be made more reliable. In addition, the spring member 7 further corrects a defect such as a pitch shift between the gears, and the gear is automatically adjusted to a correct meshing position.
[0019]
In FIG. 1, a two-dot chain line indicates an open state of the opening / closing cover 1, and the opening / closing cover 1 can be easily opened and closed around the support point 2. Further, unlike the above-described prior art, the present invention has an extremely simple structure that does not require a complicated transmission mechanism, and requires only a small number of parts.
[0020]
FIG. 2 shows an embodiment in which a spacer roller 11 is arranged coaxially with the center point of the driven gear 5 of the opening / closing cover 1 shown in FIG. As shown, a spacer roller 1 that is in contact with and engages with a spacer roller 11 is disposed on the apparatus main body 3 side. The spacer rollers 10 and 2 have the same outer diameter as the pitch circle outer diameter of the driving gear 4 and the driven gear 5. The spacer roller 11 on the side of the opening / closing cover 1 is provided with a spring member for pressing the spacer roller 11 against the spacer roller 10.
[0021]
By providing the spacer rollers 10 and 11, when the cover 1 is closed, the spacer rollers 10 and 11 abut and engage, and the driving gear 4 and the driven gear 5 are set at the correct positions, and the interference of the tooth tips is provided. It functions to prevent the like.
[0022]
FIG. 3 shows an embodiment in which the openable power transmission device of the present invention is applied to a document separation device. In the figure, a drive gear 4 is arranged on the apparatus main body 3 (FIG. 1) side, and a driven gear 5 meshing with the drive gear 4 is arranged on an open / close cover 1 (not shown) (shown in FIGS. 1 and 2). A bearing 6 that supports the central shaft 12 of the driven gear 5 is disposed on the opening / closing cover 1 side. A separation roller 13 is disposed on the center shaft 12 via a roller (not shown).
[0023]
On the other hand, a feed roller 15 is connected to the rotation shaft 14 of the drive main body 4 on the device main body 3 side. The feed roller 15 abuts and engages with the separation roller 13. The roller 16 on the rotating shaft 14 and the pickup roller 17 are connected via intermediate rollers 18 and 19. Further, the rotating shaft 14 is connected to a drive motor 21 via a reduction gear 20.
[0024]
With the above structure, the contact engagement between the separation roller 13 and the feed roller 15 is ensured, and the unillustrated document conveyed while being nipped and conveyed therebetween is more reliably separated.
[0025]
FIG. 4 shows an embodiment in which the opening / closing power transmission device of the present invention is applied to a document feeder. In this example, the feed roller 15 and the pickup roller 17 are arranged on the apparatus main body 3 side as in the case of FIG.
On the other hand, a separation roller 13 is disposed on the opening / closing cover 1 as shown in FIG. The drive gear 4 and the driven gear 5 shown in FIG. 1 and the like are not shown in FIG. 4, but are arranged at predetermined positions.
In addition, a transport roller 23 that is in contact with the transport roller 22 is disposed on the openable cover 1, and a transport roller 24 is disposed at a position of the support point 2 of the openable cover 1. As described above, also in the case of the present example, the transport of the separated document is reliably performed.
[0026]
The application examples of the present invention are not limited to those described above, and can be applied to various transport paths, separation, and fixing.
[0027]
【The invention's effect】
1) According to the opening / closing type power transmission device according to claim 1 of the present invention, when the opening / closing cover is closed, the opening / closing cover is always urged toward the device main body, so that the engagement of the power position mechanism is ensured. Done. Further, the present invention does not have a large number of components as in the prior art, has a simple structure, and can be implemented relatively inexpensively.
[0028]
2) According to the opening / closing power transmission device of the second aspect of the present invention, since the driving gear and the pair of spacer rollers having an outer diameter equal to the pitch circle of the driven gear meshing with the driving gear are arranged, the opening / closing cover is closed. At which the gears are correctly positioned.
[0029]
3) According to the opening / closing power transmission device according to the third aspect of the present invention, by applying the present invention to a document separating device, accurate document separation becomes possible.
[0030]
4) According to the opening / closing type power transmission device according to claim 4 of the present invention, gears are smoothly engaged by providing a spring member on the opening / closing cover side, and climbing and interference of tooth tips are prevented. You.
[0031]
5) According to the opening / closing power transmission device described in claim 5 of the present invention, the present invention can be applied to the document conveying device by arranging the conveying roller on the opening / closing cover side, and reliable conveyance is performed. .
[0032]
6) According to the opening / closing type power transmission device of the sixth aspect of the present invention, by disposing the conveying roller at the support point, the support point can be effectively used.
[Brief description of the drawings]
FIG. 1 is a side view showing the overall structure of the present invention.
FIG. 2 is a side view showing the periphery of a spacer roller of the present invention.
FIG. 3 is a perspective view showing an embodiment in which the present invention is applied to a document separating apparatus.
FIG. 4 is a side view showing an embodiment in which the present invention is applied to a document feeder.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Opening / closing cover 2 Support point 3 Device main body 4 Drive gear 5 Driven gear 6 Bearing 7 Spring member 8 Pressure angle direction line 9 Vertical line 10 Spacer roller 11 Spacer roller 12 Center shaft 13 Separation roller 14 Rotation shaft 15 Feed roller 16 Roller 17 Pickup Roller 18 intermediate roller 19 intermediate roller 20 principle gear 21 drive motor 22 transport roller 23 transport roller 24 transport roller

Claims (6)

An opening / closing power transmission device provided with a power transmission mechanism such as a gear and a roller engaged with each other at predetermined positions of both an apparatus body and an opening / closing cover supported by a cantilever pin so as to be openable and closable. The support point is located in the direction of the common normal line when the gears mesh with each other, and on the opposite side of the meshing point with the pressure direction line in the direction of the common normal acting on the center point of the gear on the opening / closing cover side. The opening / closing power transmission device in the image forming apparatus , wherein the opening / closing cover is urged in a direction pressed against the apparatus main body when the cover is closed . 2. The open / close power transmission device in an image forming apparatus according to claim 1, wherein the roller is a spacer roller disposed coaxially with the gear and having an outer diameter equal to a pitch circle of the gear. The open / close power transmission device of the image forming apparatus according to claim 1, wherein the rollers are a separation roller and a feed roller arranged in connection with the gear. The power transmission mechanism such as the gears and the rollers disposed on the opening / closing cover side is provided with a spring member for pressing the power transmission mechanism toward the power transmission mechanisms such as the gears and the rollers on the apparatus body side. An openable power transmission device in the image forming apparatus according to claim 1. The open / close power transmission device for an image forming apparatus according to any one of claims 1 to 4, wherein a transport roller that engages with a transport roller on the apparatus main body side is provided on the opening / closing cover side. The openable power transmission device according to claim 5, wherein one of the transport rollers is disposed at the support point of the openable cover.

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