JPH07228372A - Paper feeder - Google Patents

Abstract

PURPOSE:To provide a paper feeder applying a power transmission means, simplifying a structure further at a low cost, setting small occupying space only required, and further capable of smoothly connecting a paper feed mechanism unit to a paper feeder main unit. CONSTITUTION:A driven coupling 140 for transmitting drive force is provided in a paper feed roller in a paper feed mechanism unit made mountable/ demountable relating to a main unit which is a paper feeder main unit, and a drive coupling 142, connected to the driven coupling 140 to give drive force, is provided in the main unit. A coupling mechanism, in which drive force transmitting protrusions 140B, 142B in either one of the driven coupling 140 or drive coupling 142 are formed into one body, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device attached to an image forming unit such as an electrophotographic copying machine or a laser printer. The present invention relates to an improvement of a sheet feeding device that includes a sheet feeding mechanism unit that has a sheet feeding unit that takes out a sheet from a cassette and can be inserted into and removed from a sheet feeding device main body.

[0002]

2. Description of the Related Art Recently, an image forming apparatus having a plurality of paper feed cassettes has been put into practical use. In general, this type of image forming apparatus includes an image forming unit that forms an image on a sheet, and a sheet feeding unit that is provided below the image forming unit and that feeds the sheet toward the image forming unit. Composed of and.

The paper feed unit feeds a paper feed device main body in which a plurality of paper feed cassettes that can be pulled out to the front side are arranged, and paper in the paper feed cassettes arranged in the paper feed device main body. It is configured to have a paper feed mechanism that takes out the paper unit in a direction orthogonal to the drawing direction and feeds the paper toward the image forming unit.

Further, since the paper feeding mechanism is unitized, it goes without saying that the assembling accuracy and the assembling workability are improved, and the paper feeding mechanism unit can be freely inserted into and removed from the main body of the paper feeding device. By doing so, the configuration is such that maintenance and inspection work can be performed easily.

Conventionally, when the paper feed mechanism unit is freely inserted into and removed from the paper feed device main body as described above, one of means for transmitting driving force to the paper feed mechanism unit side is shown in FIGS. A gear mechanism type power transmission means as shown in the figure is known.

That is, the drive shaft b of the paper feed mechanism unit a
Install the driven gear c. On the other hand, on the side of the main body of the sheet feeding device (not shown), a drive gear e fitted to the drive shaft d and a rotary arm f that meshes with the drive gear e and is rotatable about the drive shaft d as a rotation center. The intermediate gear g is provided. The rotating arm f rotates counterclockwise (arrow J in the state of FIG.
Direction) is always biased so as to be rotationally displaced.

Then, when the paper feed mechanism unit a is moved to a predetermined position in the direction of arrow k so as to be attached to the main body of the paper feed device,
As shown in FIG. 18, the intermediate gear g provided on the side of the sheet feeding device main body is the driven gear c provided on the side of the sheet feeding mechanism unit a.
The drive force is transmitted to the gear.

However, this gear mechanism type power transmission means has a large number of constituent parts, a complicated structure, and high cost,
In addition, there is a problem that the space to be occupied becomes large.
Further, conventionally, as another driving force transmitting means, a coupling type power transmitting means as shown in FIGS. 19 and 20 has been known.

This mounts a driven side coupling m of a drive shaft b of a paper feed mechanism unit (not shown). On the other hand, a drive side coupling n is provided on a drive shaft d on the side of the main body of the sheet feeding device (not shown). Each of the driven side coupling m and the driving side coupling n has a plurality of driving force transmitting projections p.
... (two sheets in this description) are projected. The driven side coupling m and the driving side coupling n are connected by moving the sheet feeding mechanism unit to a predetermined position in the direction of arrow k so as to be attached to the sheet feeding device main body.

This coupling type power transmission means has a small number of constituent parts, has a simple structure and is inexpensive, and
It has the advantage of occupying less space. However, this conventional coupling type power transmission means,
Since there are a plurality of driving force transmitting projections p of the driven side coupling m and a plurality of driving force transmitting projections p of the driving side coupling n, these driving force transmitting projections p and p are shown in FIG. When they face each other as described above, there is a problem that these driving force transmitting projections p and p may come into contact with each other and cannot be connected.

[0011]

As described above, in the paper feeding device in which the paper feeding mechanism unit is attachable to and detachable from the paper feeding device main body, the drive shaft on the paper feeding device main body side is perpendicular to the drive shaft. When connecting the drive shaft of the paper feed unit,
Gear mechanism type power transmission means using a plurality of gears, rotating arms, springs, etc., or coupling type power transmission means using a drive coupling and a driven coupling are used.

However, the former gear mechanism type power transmission means has a problem that the number of constituent parts is large, the structure is complicated and the cost is high, and moreover, the occupied space becomes large. In addition, the latter coupling type power transmission means has a small number of constituent parts, a simple and inexpensive structure, and has an advantage that it occupies a small space, but on the other hand, the driving force transmission projections contact each other. Sometimes it became impossible to connect.

The present invention has been made in view of the above circumstances. An object of the present invention is to provide a paper feeding device in which the paper feeding mechanism unit is detachable from the paper feeding device main body, and has a simple structure and is inexpensive. It is an object of the present invention to provide a sheet feeding device to which a power transmission means is applied, which occupies a small space and can smoothly connect the sheet feeding mechanism unit and the sheet feeding device main body.

[0014]

As a first means for solving the above problems, the present invention has a sheet feeding device main body which accommodates a sheet feeding cassette, and a sheet feeding means which takes out a sheet from the sheet feeding cassette. A paper feed mechanism unit that can be inserted into and removed from the paper feed device body, a driven coupling provided in the paper feed mechanism unit for transmitting a driving force to the paper feeding means, and provided in the paper feed device body. A driving mechanism for connecting the driven coupling with the driven coupling and applying a driving force to the driven coupling; and a coupling mechanism having one driving force transmitting projection of the driven coupling or the driving coupling. It is configured as follows.

Further, as a second means, it has a paper feeding device main body accommodating a paper feeding cassette and a paper feeding device for taking out a paper from the paper feeding cassette, and the paper feeding device is insertable into and removable from the paper feeding device main body. A paper mechanism unit, a driven coupling provided in the paper feeding mechanism unit for transmitting a driving force to the paper feeding means, and a rotation axis core line provided in the paper feeding device main body in accordance with an inserting operation of the paper feeding mechanism unit. A coupling mechanism that includes a drive coupling that is coupled to the driven coupling in a direction orthogonal to the drive coupling to apply a driving force, and has one of the driven coupling or the driving coupling as a driving force transmitting projection. It is configured to include.

Further, as a third means, it has a sheet feeding device main body accommodating a sheet feeding cassette, and a sheet feeding device for taking out a sheet from the sheet feeding cassette, which is insertable into and removable from the sheet feeding device main body. A paper mechanism unit, a driven coupling provided in the paper feeding mechanism unit for transmitting a driving force to the paper feeding means, and a rotation axis core line provided in the paper feeding device main body in accordance with an inserting operation of the paper feeding mechanism unit. A driving coupling for applying a driving force by connecting with the driven coupling in a direction orthogonal to the driving coupling, and one of the driven coupling and the driving coupling has a driving force transmitting projection, and the driven side The gap between the mutually facing surfaces of the coupling body end surface of the coupling and the driving side coupling body is determined by the gap between the driving force transmission projections of each coupling. Larger set than Decho of, and,
The driven coupling and the coupling mechanism are set so as to be smaller than the length obtained by adding the length of the driving force transmitting projection of the driving coupling.

Further, as a fourth means, it has a sheet feeding device main body accommodating a sheet feeding cassette and a sheet feeding device for taking out a sheet from the sheet feeding cassette, which is insertable into and removable from the sheet feeding device main body. A paper mechanism unit, a driven coupling provided in the paper feeding mechanism unit for transmitting a driving force to the paper feeding means, and a rotation axis core line provided in the paper feeding device main body in accordance with an inserting operation of the paper feeding mechanism unit. A driving coupling for applying a driving force by connecting with the driven coupling in a direction orthogonal to the driving coupling, and one of the driven coupling and the driving coupling has a driving force transmitting projection, and the driven side An inclination that allows the coupling to rotate when the driving force transmitting projection of the coupling and the driving force transmitting projection of the driving side coupling come into contact with a part other than these power transmitting surfaces. And in which the guide surface was provided and formed by constituting the shape and coupling mechanism.

[0018]

According to the paper feeding device of the first means of the present invention, the paper feeding mechanism unit is provided with the driven coupling for transmitting the driving force to the paper feeding means, and is connected to the driven coupling of the paper feeding device main body. By providing a drive coupling that gives a driving force,
Since only one of the driven coupling and the drive coupling has one driving force transmitting projection, connection failure due to contact between the driving force transmitting projections can be prevented, and the connection can be smoothly performed.

According to the paper feeding device of the second means, the paper feeding mechanism unit is provided with the driven coupling for transmitting the driving force to the paper feeding device, and the paper feeding mechanism unit is inserted into the paper feeding device main body. A drive coupling is provided which is coupled with the driven coupling from the direction orthogonal to the axis of rotation along with the operation to apply a driving force, and one of the driven coupling and the drive coupling has a projection for transmitting the driving force. Therefore, it is possible to prevent connection failure due to abutting of the driving force transmitting projections, and to perform the connection smoothly.

According to the third aspect of the paper feeding device, the paper feeding mechanism unit is provided with the driven coupling for transmitting the driving force to the paper feeding device, and the paper feeding mechanism unit is inserted into the paper feeding device main body. A drive coupling is provided which is coupled with the driven coupling from the direction orthogonal to the axis of rotation along with the operation to apply a driving force, and one of the driven coupling and the drive coupling has a projection for transmitting the driving force. Therefore, it is possible to prevent the connection failure due to the contact between the driving force transmitting projections, and to perform the connection smoothly. Further, the gap between the mutually facing surfaces of the end surface of the coupling body of the driven side coupling and the end surface of the coupling body of the driving side coupling is
The driving force is set to be larger than the projection length of the driving force transmitting projection of each coupling and smaller than the length obtained by adding the lengths of the driving force transmitting projections of the driven coupling and the driving coupling. The transmission projections are securely engaged with each other, and the driving force is reliably transmitted.

According to the sheet feeding device of the fourth means, the driven coupling for transmitting the driving force to the sheet feeding means is provided in the sheet feeding mechanism unit, and the sheet feeding mechanism unit is inserted into the sheet feeding device main body. A drive coupling is provided which is coupled with the driven coupling from the direction orthogonal to the axis of rotation along with the operation to apply a driving force, and one of the driven coupling and the drive coupling has a projection for transmitting the driving force. Therefore, it is possible to prevent the connection failure due to the contact between the driving force transmitting projections, and to perform the connection smoothly. In addition, the driving force transmitting projection of the driven side coupling and the inclined guide surface that allows the coupling to rotate when the driving force transmitting projection of the driving side coupling comes into contact with a portion other than these power transmitting surfaces are formed. Therefore, the driven side coupling and the driving side coupling can be connected more smoothly.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described in detail with reference to. FIG. 1 shows an image forming unit 1.
FIG. 2 shows the outer appearance of the image forming apparatus 3 including the sheet feeding unit 2 which is the sheet feeding device of the present invention. FIG. 2 shows the internal structure of the image forming unit 1, and FIG. This is a cutaway view of a part of the body.

First, the structure of the image forming unit 1 will be described with reference to FIGS. An image forming unit 12 that forms an image by an image forming process such as charging, exposure, development, transfer, and cleaning is built in a unit body 10 that is a housing.

A glass plate (hereinafter referred to as a platen glass) 14 serving as a document placing table and a platen cover 16 for pressing the document D set on the platen glass 14 are provided on the upper surface of the unit body 10. . Further, a control panel 18 (see FIG. 1) as an input / display means is arranged at the front edge of the upper surface of the unit body 10.

At the bottom of the unit main body 10, there is provided a paper feed mechanism 20 which will be described later for supplying the paper P as a transfer target to be supplied to the image forming means 12, and on the right side of the unit main body 10. A manual paper feed tray 22 is provided, and a paper discharge tray 24 for accommodating the fixed paper P is provided on the left side of the unit main body 10.

The image forming means 12 has the following structure. That is, as shown in FIG. 1, a photosensitive drum 26 as an image bearing member is rotatably provided in a substantially central portion of the unit main body 10.

Around the photosensitive drum 26, a pre-exposure device 28 as a residual charge removing means for irradiating the photosensitive drum 26 with light along the rotation direction (direction of arrow A) to remove residual charges. , A charging device 30 as a charging means for uniformly charging the surface of the photosensitive drum 26, an LED erasing array 32 for removing charges in a non-image forming area, and an electrostatic latent image formation provided in an upper portion inside the unit main body 10. Developing means for developing an electrostatic latent image formed on the surface of the photoconductor drum 26 by slit exposure by an optical system moving type exposure device 34 as means using a powder developer (hereinafter referred to as toner). The developing device 36 is disposed in order.

Further, a toner image as a powder image formed on the photosensitive drum 26 is fed from the paper feed mechanism 20 or the manual paper feed table 22 as a transfer target paper (plain paper, OHP sheet, etc.). A transfer device 38 serving as a transfer unit that transfers the toner image to the sheet P, and a peeling device 4 serving as a peeling unit that peels the sheet P on which the toner image is transferred from the photosensitive drum 26.
0 and a cleaner device 42 as a cleaning unit for scraping off the toner remaining on the photosensitive drum 26 are arranged in order.

The exposure device 34 illuminates an original D set on the platen glass 14 provided on the upper surface of the unit main body 10 with an exposure lamp 46, which is a light source surrounded by a reflector 44, and the original D is emitted from the original D. The reflected light L is applied to the first mirror 48, the second mirror 50, and the third mirror 52.
Through the lens 54, and the reflected light L from the original D that has passed through the lens 54 is reflected by the fourth mirror 56,
It is configured to be guided to the photosensitive drum 26 via the fifth mirror 58 and the sixth mirror 60.

In the unit body 10, the paper P fed from the paper feed mechanism 20 or the manual paper feed tray 2 is provided.
A sheet conveying path 70 is formed to guide the sheet P fed from the sheet No. 2 through the sheet feeding roller 62 to the sheet ejection tray 24 via the image transfer section 68 between the transfer device 38 and the photosensitive drum 26. .

A registration roller pair 72, which is located on the upstream side of the image transfer section 68 in the paper transport path 70 and also serves as an alignment means and a transport means, is further upstream from this as a paper detection means. A pre-registration roller detector 74 is provided, and an entry guide 76 as guide means is provided between the registration roller pair 72 and the image transfer section 68.
Is provided.

Further, a conveying device 78 having an endless belt, which is located on the downstream side of the image transfer portion 68, a heating roller type fixing device 80 as a fixing means, and a paper discharge roller pair 82.
Are arranged.

In copying the document D, the photoconductor drum 26 rotates in the direction of arrow A and the residual charge is removed by the pre-exposure device 28.
Are uniformly charged by.

Next, the photosensitive drum 2 which is uniformly charged
An original D is scanned on the photosensitive drum 6 by an optical system moving type exposure device 34, and slit exposure is performed on the photosensitive drum 26, so that an electrostatic latent image corresponding to the original D is formed on the photosensitive drum 26.

The electrostatic latent image formed on the photosensitive drum 26 is developed by applying toner to the developing device 36,
A toner image is formed on the photosensitive drum 26. On the other hand, in parallel with the operation of forming the toner image on the photosensitive drum 26, the paper P fed from the paper feed mechanism 20 or the manual paper feed tray 22 strikes the stopped registration roller pair 72 and the leading edge thereof. Repositioning is performed.

Then, after the leading edge is detected by the registration roller pre-detector 74 and a predetermined time has elapsed, the registration roller pair 72 is rotated and the conveyance of the sheet P toward the image transfer portion 68 is started. The conveyed paper P is taken in by the approach guide 76.
Is guided so that the front end of the paper P comes into close contact with the photoconductor drum 26, and is sent to the image transfer section 68.
The toner image on the photoconductor drum 26 is transferred to the paper P by the action of.

Then, the paper P on which the toner image is transferred is
After being peeled off by the peeling device 40 by AC corona discharge, it is guided to the fixing device 80 via the conveying device 78, and the fixing device 80 melts and fixes the toner image on the paper P. After that, the paper P is discharged onto the paper discharge tray 24 by the paper discharge roller pair 82.

On the other hand, after the toner image is transferred onto the paper P, the cleaner device 42 removes the residual toner from the photosensitive drum 26 to enable the next copying operation. Also,
The paper feed mechanism 20 that automatically feeds the paper P includes a drawer-type paper feed cassette 100A that collectively houses a large number of papers P in a stacked state. The paper feed cassette 100A is
The guide members 102, 102 provided on both the left and right wall surfaces are used as guides to move in the front-rear direction, which is the first direction (the arrow B direction in FIG. 1 and the opposite arrow C direction). It is configured so that it can be inserted and removed from the front side of the main body 10.

Then, the uppermost sheet P stored in the paper feed cassette 100A is inserted into and removed from the paper feed cassette 100A via the pickup roller 104 as a paper take-out means in the first direction (front-back direction). ) Orthogonal to
The sheet is taken out in the right direction, and is fed to the separation / conveyance mechanism 108 that conveys toward the pair of conveyance rollers 106 disposed in the upstream portion 70A of the sheet conveyance path 70.

The separating / conveying mechanism 108 is provided with a paper feed roller 110 as a paper feed means for carrying the paper P, and a second and subsequent sheets which are provided in pressure contact with the paper feed roller 110 and overlap with the uppermost paper P. And a separating member 112 as a separating means for separating the paper P, and only the uppermost paper P is fed to the upstream portion 70A of the paper transport path 70.

Next, the basic structure of the paper feeding unit 2 which is the paper feeding device of the present invention will be described with reference to FIGS. 1, 3, and 4 to 11. First, the basic configuration will be described with reference to FIGS. 1, 3, and 4. The paper feeding unit 2 is
The paper feed cassettes 100B and 100C are arranged in two upper and lower stages.

The paper feed cassettes 100B and 100C are
Like the paper feed cassette 100A of the image forming unit 1,
The guide members 102, 102 provided on both the left and right wall surfaces are used as guides to move in the front-rear direction, which is the first direction (the arrow B direction in FIG. 1 and the opposite arrow C direction). It is configured such that it can be inserted into and removed from the front side of the unit main body 120 which is the main body of the paper apparatus.

Further, as shown in FIG. 3, the sheet feeding cassettes 100B, 100 are provided at the right side portion of the unit main body 120.
A paper feed mechanism unit 122 is provided for taking out the paper P in C and feeding it to the upstream portion 70A of the paper transport path 70 of the image forming unit 1. As shown in FIG. 4, the paper feed mechanism unit 122 can be inserted into and removed from the right side surface of the unit main body 120 in the left-right direction (the arrow E direction and the opposite arrow F direction).

Next, the structure of the paper feed mechanism unit 122 will be described with reference to FIGS. As shown in FIG. 3, the paper feed mechanism unit 122 is a horizontal first and second horizontal extension that extends to the upper right end side of the paper feed cassettes 100B and 100C when the paper feed mechanism unit 122 is attached to the unit main body 120. Support frames 123A, 12
A unit frame 123 having 3B and exhibiting an F-shape when viewed from the rear side is provided.

Further, in the unit frame 123, similarly to the paper feed mechanism 20 of the image forming unit 1, the uppermost sheet of paper P stored in the paper feed cassettes 100B and 100C.
Pick-up rollers 104, 104 as sheet take-out means for taking out in the right direction which is a second direction orthogonal to the first direction (front-back direction) which is the inserting / removing direction of the paper feed cassettes 100B, 100C (except for FIG. Only one is shown).

Further, the pickup roller 104,
In the take-out direction of the paper P of the sheet 104, the paper feed path 7 that joins only the uppermost paper P taken out by the pickup rollers 104, 104 with the upstream portion 70A of the paper transport path 70.
A separation / conveyance mechanism 108 that conveys toward the pair of conveyance rollers 106 arranged at 0B is provided.

The separating / conveying mechanism 108 is provided with a paper feed roller 110 as a paper feed means for carrying the paper P, and a second and subsequent sheets which are provided in pressure contact with the paper feed roller 110 and overlap with the uppermost paper P. And a separating member 112 as a separating unit that separates the paper P.

Further, the pickup rollers 104, 1
As shown in FIG. 6, 04 is a pickup roller shaft 12
4, the pickup roller shaft 124 is supported by a pair of roller shaft support arms 128 and 128 that are rotatably provided with a drive shaft 126 that transmits a driving force to the paper feed roller 110 as a rotation fulcrum. There is.

These roller shaft support arms 128, 128
Is configured so that it can be rotationally displaced by the pickup roller contact / separation mechanism 130. Then, the paper feed cassette 100
When B and 100C are mounted at predetermined positions in the unit main body 120, the pickup rollers 104 and 104 are in contact with the paper P as shown by the chain double-dashed line in FIG. Unit body 1
At the time of inserting / removing with respect to 20, the pickup rollers 104, 104 are moved to the sheet feeding cassette 100 as shown by the solid line in FIG.
B and 100C are escaped and retracted upward.

The drive force of the drive shaft 126 is transmitted to the pickup roller shaft 124 via a power transmission system 132 (see FIG. 6) including a pulley, a timing belt, etc., and the pickup roller shaft 124 is rotated to take out the paper P. ing. At this time, the paper feed roller 110 also rotates in the same rotation direction.

Further, at one end of the drive shafts 126, 126,
Driven side couplings 140 are respectively mounted as shown in FIG. 6, and these driven side couplings 140, 1 are attached to the unit main body 120 side as shown in FIG.
Drive side couplings 142, 142 engaging with 40 are attached.

Then, when the paper feed mechanism unit 122 is moved in the direction of arrow E in FIGS. 4 and 8 so as to be attached to the unit main body 120 of the paper feed unit 2, as shown in FIG. The driving force is transmitted to the drive shafts 126, 126.

At this time, at the same time, the driven side couplings 144 and 144 (see FIG. 6) for the conveying roller pair 106 located on the front side when viewed from the insertion direction are the unit main body 120.
The drive side couplings 146 and 146 (see FIG. 7) provided on the side are engaged with each other.

The upper drive side coupling 14 is also provided.
2, 146 are driven by a drive mechanism 148 (see FIG. 7) having a motor and a clutch incorporated in the unit main body 120, and the lower drive side couplings 142, 146.
Is a power transmission system 1 including a clutch, a pulley, a belt, etc.
The driving force of the driving mechanism 148 is transmitted via 50.

Next, the driven side coupling 140 and the driving side coupling 142 for transmitting the driving force to the drive shafts 126, 126 of the sheet feeding roller 110 of the sheet feeding mechanism unit 122.
The coupling mechanism 160 including the above will be described with reference to FIGS. 8 to 14.

The driven side coupling 140 includes the drive shaft 12
6, and two driving force transmitting projections 140B symmetrically projected on the front end surface of the coupling body 140A with a phase shift of 180 degrees with the drive shaft 126 as a boundary. It consists of 140B.

On the other hand, the drive side coupling 142 is a coupling body 142A fitted to the body side drive shaft 162.
And a single driving force transmitting projection 142B provided on the front end surface of the coupling body 142A.

Further, when the paper feed mechanism unit 122 is set at a predetermined position of the unit main body 120,
As shown in FIG. 9, the drive shaft 1 of the paper feed mechanism unit 122.
26 and the main body side drive shaft 162 on the unit main body 120 side are coaxial with each other.

Further, the driven side coupling 140 at this time
A gap W is formed between the end surfaces of the coupling body 140A and the end surface of the coupling body 142A of the drive side coupling 142 as shown in FIG. This gap W is formed by the driving force transmitting projection 14
0B protrusion length H ₁ and driving force transmitting protrusion 142B
Is set to be larger than the projection length H _{2 of} the projection 140 (W> H ₁ , W> H ₂ ), and the projection length H ₁ of the projection 140B and the projection 142 are set.
It is smaller than the length of B protruding length H ₂ (W <H
₁ + H ₂ ) It is set.

By adopting the coupling mechanism 160 having one driving force transmitting projection 142B of the one coupling 142 as described above, the driven side coupling 140 and the driving side coupling 142 are connected. Can be smoothly performed even when the angle is deviated, and the paper feed mechanism unit 122 including the driven side coupling 140 attached to the drive shaft 126 in the recessed position where it is difficult to manually adjust the rotation, Unit body 120
It can be mounted extremely easily with respect to.

Further, as shown in FIG. 12, the driven side coupling 140 is driven by the driving force transmitting projections 140B, 140B of the driven side coupling 140 and the driving force transmitting projection 142B of the driving side coupling 142. The inclined guide surface 140 that rotates the coupling when the force transmission projection 140B and the driving force transmission projection 142B of the drive side coupling 142 contact with each other except the power transmission surface.
It has a shape having C and 142C.

Then, the angle of the driven side coupling 140 or the driving side coupling 142 is deviated, and as shown in FIG. 13, the driving force transmitting projection 140B of the driven side coupling 140 and the driving force of the driving side coupling 142 are moved. When a portion other than the power transmission surface with the transmission protrusion 142B comes into contact,
As shown in FIG. 4, the driven side coupling 140 rotates in the direction of the arrow so that the driven side coupling 140 and the driving side coupling 142 are smoothly connected.

Of course, the driving side coupling 142, not the driven side coupling 140, may rotate in the direction of the broken arrow, or both may rotate. In the description of the above-described embodiment, the driven coupling 140 has two driving force transmitting projections 140B and 140B, and the driving coupling 142 has one driving force transmitting projection 142.
However, the present invention is not limited to this, and as shown in FIGS. 15 and 16, one driven force transmitting projection 140B is provided on the driven side coupling 140, and the driving side coupling 142 is provided. Two driving force transmitting projections 142B and 142B may be provided on the.

The point is that one of the couplings should have one driving force transmitting projection and the other coupling should have two or more. The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0065]

As described above, the device of the present invention has the following effects. According to the paper feeding device of the first aspect, the driven coupling for transmitting the driving force to the paper feeding means is provided in the paper feeding mechanism unit, and the driving force is provided by connecting with the driven coupling of the paper feeding device main body. The drive coupling is provided, and the driving force transmitting projection of either one of the driven coupling and the driving coupling is provided as one, so that connection failure due to contact between the driving force transmitting projections can be prevented, and the connection is smooth. -You can do it.

According to the paper feeding device of the second aspect,
The paper feed mechanism unit is provided with a driven coupling for transmitting the driving force to the paper feed means, and is connected to the driven coupling from the direction orthogonal to the axis of the rotation axis along with the insertion operation of the paper feed mechanism unit in the main body of the paper feed device. A drive coupling that applies a driving force is provided, and one of these driven couplings and drive couplings has one projection for transmitting the driving force, so that connection failure due to contact between the projections for transmitting the driving force is prevented. Yes, the connection can be done smoothly.

According to the paper feeding device of the third aspect,
The paper feed mechanism unit is provided with a driven coupling for transmitting the driving force to the paper feed means, and is connected to the driven coupling from the direction orthogonal to the axis of the rotation axis along with the insertion operation of the paper feed mechanism unit in the main body of the paper feed device. Since a drive coupling for applying a driving force is provided and only one of the driven coupling and the drive coupling has a driving force transmitting projection, connection failure due to contact between the driving force transmitting projections can be prevented. The connection can be done smoothly. Further, the gap between the mutually facing surfaces of the end surface of the coupling body of the driven side coupling and the end surface of the coupling body of the driving side coupling is set to be larger than the protruding length of the driving force transmitting projection of each coupling, In addition, the driving force transmitting projections of the driven coupling and the driving coupling are set to be shorter than the length obtained by adding the lengths, so that the driving force transmitting projections are securely engaged with each other, and the driving force is transmitted. Will be certain.

According to the sheet feeding device of the fourth aspect,
The paper feed mechanism unit is provided with a driven coupling for transmitting the driving force to the paper feed means, and is connected to the driven coupling from the direction orthogonal to the axis of the rotation axis along with the insertion operation of the paper feed mechanism unit in the main body of the paper feed device. Since a drive coupling for applying a driving force is provided and only one of the driven coupling and the drive coupling has a driving force transmitting projection, connection failure due to contact between the driving force transmitting projections can be prevented. The connection can be done smoothly. In addition, the driving force transmitting projection of the driven side coupling and the inclined guide surface that allows the coupling to rotate when the driving force transmitting projection of the driving side coupling comes into contact with a portion other than these power transmitting surfaces are formed. Therefore, there is an effect that the driven side coupling and the driving side coupling can be connected more smoothly.

[Brief description of drawings]

FIG. 1 is an external view of an image forming apparatus to which an embodiment of a sheet feeding device of the invention is applied.

FIG. 2 is a diagram showing an internal structure of an image forming unit of the image forming apparatus shown in FIG.

FIG. 3 is a diagram showing an internal structure of a paper feeding unit of the image forming apparatus shown in FIG. 1 with a part of a housing cut away.

FIG. 4 is a view showing a state in which the paper feeding mechanism unit is also pulled out from the paper feeding device main body.

FIG. 5 is a front view of the paper feed mechanism unit according to the embodiment.

FIG. 6 is a plan view of the paper feed mechanism unit of the embodiment.

FIG. 7 is a side view of the sheet feeding device main body after the sheet feeding mechanism unit is pulled out.

FIG. 8 is a perspective view showing a state before coupling of the coupling mechanism which is a main part of the embodiment.

FIG. 9 is a perspective view showing a state after coupling of the coupling mechanism, which is a main part of the embodiment.

FIG. 10 is a view of the coupling mechanism, which is a main part of the same embodiment, in a state before being coupled, as viewed from the axial direction.

FIG. 11 is a view of the coupling mechanism, which is a main part of the embodiment, after connection, viewed from a direction orthogonal to the axial direction.

FIG. 12 is an axial view of the coupling mechanism, which is a main part of the embodiment, before connection.

FIG. 13 is an axial view showing a state in which the driving force transmitting projections are in contact with each other immediately before the coupling mechanism, which is a main part of the embodiment, is connected.

FIG. 14 is an axial view of a state in which the driving force transmitting protrusions are in contact with each other immediately before the coupling mechanism, which is a main part of the embodiment, is connected.

FIG. 15 is a view of the coupling mechanism, which is a main part of the second embodiment of the present invention, in a state before coupling, as viewed from the axial direction.

FIG. 16 is a view of the coupling mechanism, which is an essential part of the second embodiment, after connection, viewed from a direction orthogonal to the axial direction.

FIG. 17 is a perspective view showing a first conventional example and showing a state before connection.

FIG. 18 is a perspective view showing a state after connection, similarly showing the first conventional example.

FIG. 19 is a view showing a second conventional example, which is seen from the axial direction in a state before connection.

FIG. 20 is a perspective view showing a second conventional example and showing a state immediately before connection.

[Explanation of symbols]

2 ... Paper feeding unit (paper feeding device), 100B, 100C ...
Paper feed cassette, 104 ... Pickup roller (paper take-out means), 106 ... Conveying roller pair, 108 ... Separation / conveyance mechanism, 110 ... Paper feeding roller (paper feeding means), 112 ... Separation member (separation means), 120 ... Unit body (Paper feeding device main body), 122 ... Paper feeding mechanism unit, 126 ... Drive shaft, 1
40 ... Driven side coupling, 140A ... Coupling body, 140B ... Driving force transmitting projection, 142 ... Driving side coupling, 142A ... Coupling body, 142B ... Driving force transmitting projection, 160 ... Coupling mechanism, 162 ...
Body side drive shaft, P ... Paper.

Claims (4)

[Claims] 1. A sheet feeding device main body containing a sheet feeding cassette, and a sheet feeding mechanism unit which has a sheet feeding means for taking out a sheet from the sheet feeding cassette and which can be inserted into and removed from the sheet feeding device main body. A driven coupling provided in the sheet feeding mechanism unit for transmitting a driving force to the sheet feeding means; and a drive coupling provided in the sheet feeding device main body and coupled with the driven coupling to apply a driving force, And a coupling mechanism having one driving force transmitting projection of one of the driven coupling and the driving coupling. 2. A paper feeding device main body containing a paper feeding cassette, and a paper feeding mechanism unit which has a paper feeding means for taking out a paper from the paper feeding cassette and is insertable into and removable from the paper feeding device main body. The driven coupling provided in the paper feeding mechanism unit for transmitting the driving force to the paper feeding means and the driven coupling provided in the paper feeding device main body from the direction orthogonal to the axis of rotation with the insertion operation of the paper feeding mechanism unit. A driving mechanism for connecting the driven coupling to apply a driving force, and a coupling mechanism having one driving force transmitting projection of either the driven coupling or the driving coupling. A paper feeding device characterized by the above. 3. A paper feeding device main body containing a paper feeding cassette, and a paper feeding mechanism unit which has a paper feeding means for taking out a paper from the paper feeding cassette and is detachable from the paper feeding device main body. The driven coupling provided in the paper feeding mechanism unit for transmitting the driving force to the paper feeding means and the driven coupling provided in the paper feeding device main body from the direction orthogonal to the axis of rotation with the insertion operation of the paper feeding mechanism unit. A drive coupling that is coupled to the driven coupling to apply a driving force is provided, and one of the driven coupling and the drive coupling has a driving force transmitting projection, and a coupling body of the driven side coupling. The gap between the end faces of the drive side coupling and the end face of the coupling body of the drive-side coupling is set to be larger than the protrusion length of the driving force transmission projection of each coupling. Is, and, the sheet feeding apparatus characterized by comprising anda coupling mechanism set smaller than the length plus the length of the driving force transmission projections of the driven coupling and the driving coupling. 4. A paper feeding device body containing a paper feeding cassette, and a paper feeding mechanism unit which has a paper feeding means for taking out a paper from the paper feeding cassette and is detachable from the paper feeding device main body. The driven coupling provided in the paper feeding mechanism unit for transmitting the driving force to the paper feeding means and the driven coupling provided in the paper feeding device main body from the direction orthogonal to the axis of rotation with the insertion operation of the paper feeding mechanism unit. A drive coupling is provided that is coupled to the driven coupling to apply a driving force, and one of the driven coupling and the drive coupling has a projection for transmitting the driving force, and the driving force of the driven side coupling is transmitted. The sloping guide surface is formed so that the coupling rotates when the driving projection and the driving force transmission projection of the driving side coupling are in contact with a portion other than these power transmission surfaces. Sheet feeding apparatus characterized by being provided with Ppuringu mechanism.