JP3311049B2 - Paper feeder and image forming apparatus having the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder provided in an image forming apparatus such as a copying machine, a printer, a facsimile, and the like. More specifically, sheets of various sizes are supplied from one tray by one tray. The present invention relates to a feedable multi-sheet feeding device.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus, for example, an electrophotographic copying machine, is provided with a multi-sheet feeding device capable of manually feeding sheets of various sizes from one tray. In this multi-sheet feeding device, a separation method is generally used in which a sheet to be fed is pressed against a sheet feeding roller by a separation pad made of a material in which cork is mixed with urethane rubber to separate the sheet.

An example of this type of conventional multi-sheet feeding device will be described with reference to FIG.

FIG. 1 shows a general multi-sheet feeding device provided in a copying machine, and this sheet feeding device is used for manually feeding sheets.

In FIG. 1, reference numeral 1 denotes a paper feed roller, which is rotatable in a direction indicated by an arrow about a paper feed roller shaft 46 rotatably supported by the support member 13. A separation pad 5b fixed to the free end of the separation pad arm 5 is pressed against the paper feed roller 1. The separation pad arm 5 has a base portion rotatably supported by a support shaft 5a, and is urged clockwise in the figure by the elastic force of the pressure spring 6, and the separation pad 5b is urged by this urging force.
Only the paper feed roller 1 is pressed.

The paper feed tray 30 has a free end rotatably supported by a support shaft 30a.
The sheet material P stacked thereon is aligned in the width direction by a regulating plate (not shown) fixed to the paper feed tray 30 and a regulating plate 31 that can move forward and backward with respect to the regulating plate. The middle plate 35 on which the leading end of the sheet material P is placed is supported by a support shaft 33.
And is fixed to a middle plate holder 32 which is rotatably supported by a shaft, and is urged upward by a pressure spring 36. The position of the middle plate 35 is controlled by a cam 45 (see FIG. 5).

FIG. 5 shows a state in which the paper feed tray 30 is moved to a position where paper can be fed. When the sheet material P is stacked on the sheet feed tray 30, the detection lever 43 rotates clockwise in the drawing around the support shaft 43a to turn on a sheet detection sensor (not shown) composed of a photo interrupter.
The presence of the sheet material P is detected.

FIG. 6 is a plan view of a drive unit of the multi sheet feeder.

A feed roller shaft 46 to which the feed roller 1 is fixed is rotatably mounted via a bearing 19 on a pair of side plates 12 (the other is not shown) of the apparatus. The extension of the paper roller shaft 46 is engaged with an electromagnetic clutch 50 mounted on the side plate 47. A drive gear 49 connected to a drive source (not shown) and rotatably supported by a support shaft 49a is disposed between the side plates 12 and 47. The drive gear 49 includes the electromagnetic clutch Fifty input gears 50a are engaged.

The drive gear 49 is further meshed with an input gear 52a of a spring clutch 52. The spring clutch 52 includes a boss 52b fixed to the support shaft 51, and a clutch spring 52c interposed between the boss 52b and the input gear 52a. An operating member of a solenoid (not shown) is engaged with the clutch spring 52c to restrict the rotation of the clutch spring 52c. In this state, the input gear 52a idles even if the drive gear 49 rotates.

The support shaft 51 is rotatably mounted on the side plates 12 and 47. A gear 53 fixed to the support shaft 51 meshes with a gear 55 fixed to a support shaft 56. I have. A cam 45 is fixed to an extension of the support shaft 56 extending inside the side plate 12.
Is controlled by the disconnection of the spring clutch 52, and FIG.
, Ie, the contact and separation between the sheet feeding roller 1 and the sheet P.

FIG. 7 shows a middle plate holder 32 integrated with a middle plate 35.
And an operation diagram of the cam 45 for controlling the middle plate 35. The middle plate 35 integral with the middle plate holder 32 has a length to support the leading end of the sheet material P over the entire surface of the sheet material P in the width direction. 59 directions).

FIG. 7A shows a state in which the contact surface 35a of the middle plate 35 is pressed downward by the large diameter portion of the cam 45, and the distance between the middle plate 35 and the paper feed roller 1 is shown. Indicates the most distant state. In this state, as shown in FIG. 8A, the sheet material P can be stacked on the sheet feeding tray 30, and a gap ΔA is opened between the sheet material P and the sheet feeding roller 1. When a solenoid (not shown) is actuated by a paper feed command from the apparatus main body and the spring clutch 52 is connected,
As shown in (b), when the cam 45 rotates in the direction of the arrow 57 and the large-diameter portion of the cam 45 separates from the intermediate plate 35 and the intermediate plate holder 32, the intermediate plate holder 32 is driven to move in the direction of the arrow 59. It turns and rises.

FIG. 7C shows a state in which the intermediate plate 35 is rotated to the upper limit position and is separated from the cam 45, and the sheet material P on the sheet feeding tray 30 is shown in FIG. 8B. Is pressed against the paper feed roller 1 as described above. After the sheet material P is sent out by the rotation of the feed roller 1, the cam 45 further rotates and abuts on the middle plate 35 as shown in the figure (d), and the rotation of the cam 45 pushes down the middle plate 35. . Thereby, the paper feed tray 3
The sheet material P on 0 is separated from the sheet feeding roller 1 as shown in FIG. When the middle plate 35 is rotated to the position shown in FIG. 7A, the connection state of the spring clutch 52 is disconnected, so that the middle plate 35 stops at the position shown in FIG. 7A. FIG. 4 shows a flowchart of the paper feeding operation.

[0015]

In the above-mentioned prior art, as the number of copies made by manual paper feed advances, the paper feed roller 1 gradually deteriorates due to wear, dirt, etc., and does not function as a paper feed roller. If
Roller replacement is required.

However, in the conventional apparatus, the paper feed roller shaft 46 for supporting the paper feed roller 1 is composed of a single shaft as shown in FIG. Is removed, and then the multi-sheet feeding device unitized for manual feeding is disassembled and the sheet feeding roller 1 is replaced, which is troublesome and troublesome.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding apparatus which can easily replace a sheet feeding roller in a multi sheet feeding apparatus and has improved serviceability.

[0018]

According to the present invention, there is provided a sheet feeding apparatus for feeding a sheet by a sheet feeding roller supported by a rotating sheet feeding roller shaft, wherein the sheet feeding roller shaft is connected to the sheet feeding roller. A roller support shaft for fixedly supporting the shaft, a transmission shaft on the same axis as the roller support shaft for transmitting a rotational force to the roller support shaft, and a shaft joint for connecting and supporting the roller support shaft and the transmission shaft. And a joint bearing for rotatably and slidably holding the shaft joint, and sliding the shaft joint held by the joint bearing in a direction away from the roller support shaft. Can be detached from the shaft coupling.

[0019]

The feed roller shaft for rotating the feed roller is divided into a roller support shaft for fixedly supporting the rotary feeder and a transmission shaft for transmitting a rotational force to the roller support shaft. Are connected on the same axis.

The rotational force input to the transmission shaft is transmitted to the roller support shaft and a paper feed roller integral with the roller support shaft via a shaft joint held by a joint bearing. Are fed while being separated one by one by the separating means. When the paper feed roller is replaced, the shaft joint is slid to the roller support shaft side to remove one end of the roller support shaft.

Thus, without removing the transmission shaft,
Only the roller support shaft and the paper feed roller integrated therewith can be easily replaced with a new one, and the serviceability can be improved.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. The components having the same functions as those shown in FIGS. 3 and 5 are denoted by the same reference numerals, and the paper feed tray (stacking means) and the separation pad (separating means) are the same as those shown in FIGS. Since it has a configuration, its illustration and description are omitted.

FIGS. 1A and 1B are front views of a sheet feeding roller portion of the sheet feeding apparatus of the present invention. FIG. 1A shows a state in which the sheet feeding roller is normally used, and FIG. It shows the state at the time of performing.

In FIG. 1, a support member 13 having a pair of arms 13a and 13b is fixed between both side plates 11 and 12 of the apparatus. The separation pad 5b (see FIG. 3) of the separation pad arm 5 is pressed against the paper feed roller 1 integral with the roller support shaft 2a in the rotation direction by the elastic force of the pressure spring 6.

The paper feed roller shaft 2 for supporting and rotating the paper feed roller 1 is divided into two parts: the above-mentioned roller support shaft 2a and a transmission shaft 2b for transmitting a rotational force to the roller support shaft 2a. It is composed of two shafts and a shaft joint 3 connecting the two shafts as described later. One end of the roller support shaft 2a is rotatably supported by the arm 13a via a bearing 16 and is prevented from coming off by a stopper member 17. Further, a D-cut portion 2c formed at the other end of the roller support shaft 2a is non-rotatably and slidably mounted in a hole in the shaft coupling 3.

The shaft coupling 3 is rotatably and slidably mounted on an arm portion 13b of the support member 13 via a coupling bearing 15, and a flange portion 3a formed on the shaft coupling 3 is provided.
The roller support shaft 2
Movement to the a side is regulated.

A D-cut portion 2d is formed at one end of a transmission shaft 2b from which a rotational force to the paper feed roller 1 is input from a drive source. Impossible and slidably fitted. The fitting portion of the D-cut portion 2d has a gap that allows the shaft joint 3 to slide a predetermined distance x toward the transmission shaft 2b, and at this position, the end of the shaft joint 3 It is locked by. The transmission shaft 2 b has one end supported by the shaft coupling 3 and the other end rotatably supported by the side plate 12 via a bearing 19.

The depth of the fitting portion of the roller support shaft 2a to the shaft joint 3 is the maximum sliding distance x of the shaft joint 3.
At least less. This allows
When the shaft joint 3 is slid toward the transmission shaft 2b, the connection between the roller support shaft 2a and the shaft joint 3 is released, and the roller support shaft 2a can be removed from the shaft joint 3.

If the paper feed function is deteriorated due to wear of the paper feed roller 1 due to repeated use of the paper feed device, the paper feed roller 1 needs to be replaced. To perform this replacement, with the cover (not shown) of the apparatus opened, the stopper 7 is removed, and then the shaft coupling 3 is slid toward the transmission shaft 2b, as shown in FIG. As a result, the roller support shaft 2a
As shown in the figure, it is possible to easily take out only the paper feed roller 1 and the roller support shaft 2a outside the apparatus, and replace them.

FIG. 2 is a vertical sectional side view of the sheet feeding roller shaft 2, and FIG. 2A shows a normal state of the sheet feeding roller shaft 2. (B) shows a state in which the shaft coupling 3 is slid in the releasing direction (toward the transmission shaft 2b) by a distance x when the paper feed roller 1 is replaced, and when the sliding of the shaft coupling 3 is restricted, the roller support is supported. The state in which the shaft 2a comes off the shaft coupling 3 is shown.

When the shaft joint 3 is slid toward the transmission shaft 2b, the slide is restricted at a distance x by the contact between the hole of the shaft joint 3 and each end face of the transmission shaft 2b. Since the end of the joint 3 on the roller support shaft 2a side is engaged with the joint bearing 15, the shaft joint 3 and the transmission shaft 2b are still held by the device.

[0032]

As described above, according to the present invention, the paper feed roller shaft of the paper feed roller is composed of a roller support shaft integrated with the paper feed roller, and a transmission shaft transmitting torque to the roller support shaft. And the two shafts are connected by a slidable shaft joint. When replacing the paper feed roller, only the shaft joint can be slid to take out only the roller support shaft and the paper feed roller integrated with it. The paper feed roller can be easily replaced, and the serviceability of the apparatus can be improved.

[Brief description of the drawings]

FIG. 1A is a front view of a sheet feeding roller unit of a sheet feeding device according to the present invention, and FIG. 1B is an operation diagram when a sheet feeding roller is replaced.

FIG. 2 is a longitudinal sectional side view of a roller support shaft, a transmission shaft, and a shaft coupling part.

FIG. 3 is a side view showing an example of a conventional sheet feeding device.

FIG. 4 is a flowchart of a sheet feeding operation.

FIG. 5 is an operation diagram of FIG. 3;

FIG. 6 is a plan view of the driving unit.

FIG. 7 is an operation diagram of a middle plate and a cam for driving the same.

FIG. 8 is a side view of the sheet feeding device showing the sheet setting operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed roller (rotary feed body) 2 Paper feed roller shaft 2a Roller support shaft 2b Transmission shaft 3 Shaft joint 5b Separation pad (separation means) 15 Joint bearing 31 Regulator plate (Regulator) 35 Middle plate (Pressurizer)

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

Claims (2)

(57) [Claims] (1)Supported on a rotating paper feed roller shaft
Paper feeder that feeds sheets by the paper feed rollers
hand, The feed roller shaft,  A roller support shaft for fixedly supporting the paper feed roller; and the roller support shaft being on the same axis as the roller support shaft.
A transmission shaft for transmitting a rotational force to the shaft, and a shaft coupling for connecting and supporting the roller support shaft and the transmission shaft.
When,Composed of Joint bearing for holding the shaft joint rotatably and slidably
Provided, the said joint held by the bearing Shaft coupling in front
Slide away from the roller support shaft
The roller support shaft can be removed from the shaft coupling by
A sheet feeding device. (2)Supported on a rotating paper feed roller shaft
Paper feeder that feeds the sheet by the paper feed roller
In the image forming apparatus, The paper feed roller shaft of the paper feeder,  A roller support shaft for fixedly supporting the paper feed roller; and the roller support shaft being on the same axis as the roller support shaft.
A transmission shaft for transmitting rotational force to the shaft, and a shaft coupling for connecting and supporting the roller support shaft and the transmission shaft.
When,Composed of Joint bearing for holding the shaft joint rotatably and slidably
Provided and held by the joint bearing Shaft coupling
By sliding it away from the roller support shaft.
The roller support shaft is removable from the shaft coupling.
An image forming apparatus, comprising: