JPH0218233A - sheet feeding device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a sheet feeding device used in an image forming apparatus such as a copying machine or a laser beam printer. The present invention relates to a feeding device equipped with a sheet storage device (hereinafter referred to as a cassette) having a middle plate.

(B) Prior Art Conventionally, cassettes equipped with a middle plate have been known.As shown in FIG. It has a T-shaped middle plate 3' in plan view which is supported by. At a position sandwiching the middle plate 3, a width regulating plate 7' is fixed to a pair of racks 6 that mesh with the pinion gear 5, and regulates the movement of the sheet in the width direction.
9' are arranged, and these width regulating plates 7'9' can be moved in the six directions of arrows. Further, the tip end 7b of one width regulating plate 7' is bent approximately horizontally to regulate the amount of sheets loaded on the intermediate plate 3, and the lower part of the width regulating plate 7' A not-shown protrusion is provided, and the protrusion engages with a groove 10 carved in the main body 2 corresponding to various sheet sizes. A suppressing plate 11 is supported by the other width regulating plate 9' via a leaf spring 12, and the pressing plate 11 presses the sheet against the width regulating plate 7. Further, at the rear of the middle plate 3, a rear end regulating plate 13 is supported to be slidable in the direction of arrow B with respect to the main body, and a protrusion (not shown) is provided at the lower part of the rear end regulating plate 13. Further, the protrusion is adapted to engage with a groove 15 carved in the main body 2 corresponding to various sheet sizes.

On the other hand, the sheet feeding device 16 including the cassette 1' has a rotatable shaft 17, as shown in FIGS. 9 and 10.
An occluded paper feed roller 19 and an auxiliary cam 20 fixed to the
An auxiliary roller 21 is supported on the shaft 17 so as to freely rotate.

Further, downstream of the paper feed roller 19, a vertical guide 22.
23 are disposed, and a separation pad 25 is disposed at the upstream end of the lower guide 23. In addition, the lower guide 23
is rotationally biased counterclockwise by a spring 26, so that the separation pad 25 is pressed against the overlapping paper roller 19. Further, a pair of registration rollers 27 is arranged downstream of the upper and lower guides 22, 23. The paper feed device 16 has a lift device 29 below the paper feed roller 19, and the lift device 29 includes a lifter 30 that pushes up the middle plate 3, and a shaft 31 that supports the lifter 30. and a spring 32 that biases the lifter to rotate.

When feeding the sheet S from the cassette 1', the operator first places the sheet S on the middle plate 3' of the cassette 1', and then places the sheet S on the width regulating plates 7', 9' and the trailing edge regulating plate 13. is moved to a position corresponding to the size of the sheet S. Thereby, the sheet S is restricted from moving in the width direction and the rear direction. Then, when the cassette 1' is attached to the main body of the image forming apparatus, the lid 30 is inserted through an opening (not shown) provided at the bottom of the cassette 1', and the lifter 30 is moved by the biasing force of the spring 32 to the middle plate 3'. push up. As a result, the sheets S stacked on the intermediate plate 3' are pressed against the paper feed roller 19 or the auxiliary roller 21. Furthermore, if the start key (not shown) is pressed in this state,
The paper feed roller 19 starts rotating, and the sheets S stored in the cassette 1' are separated one by one by the roller 19 and the separation pad 25, and only the uppermost sheet S is fed.

Then, the sheet S is guided to a pair of registration rollers 27 by upper and lower guides 22 and 23, and synchronously conveyed downstream by the pair of rollers 27 that start rotating at a predetermined timing.

(C) Problems to be Solved by the Invention By the way, in the above-mentioned cassette 1', 60 to 100
The structure allows for optimal feeding of sheets of about 100 g/m' without double feeding, etc., so it is possible to feed special sheets with folded edges and air spaces, such as envelopes. When trying to feed the special sheet, the tip of the special sheet touches the separation pad 2.
5, the special sheet is so stiff that it does not follow the separation pad 25 like a normal sheet, and the frictional resistance becomes large, which sometimes makes it impossible to feed the special sheet. In other words, with plain paper, when the leading edge of the paper hits the separation pad, it buckles and follows the separation pad, so the frictional resistance is small, but with envelopes, the so-called strong clothing prevents buckling. This is because force is applied in the direction of collision with the separation pad. In addition, when the special sheet comes into contact with the separation pad 25, the special sheet causes the separation pad 25 to
is pushed down, and the angle formed between the special sheet and the separation pad 25 becomes even larger, resulting in even greater frictional resistance, which sometimes makes it impossible to feed the special sheet. Furthermore, since special sheets such as envelopes are thick, when the special sheet enters between the auxiliary roller 21 and the separation pad 25, it acts like a wedge and generates a very large resistance, making it difficult to feed the special sheet. There were times when I couldn't send it.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a sheet feeding device that can smoothly separate and feed special sheets such as envelopes.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, as shown in FIGS. 1 and 2, a large number of sheets (
An intermediate plate (36) loaded with sheets (S) and movably supported, and a widthwise or rearward movement of the sheet (S) depending on the size of the sheet (S) loaded on the intermediate plate (36). A sheet storage device (1) having movable regulation plates (7, 9) for regulating movement, and sheets (S) loaded on the intermediate plate (36).
a feeding rotating body (19) that feeds the feeding rotating body (19);
), a separation pad (25) for separating the sheets (S) fed by the intermediate plate (36) one by one, It is characterized by comprising a moving means (36a) for moving the intermediate plate (36) in the vertical direction so as to change the angle of approach to the pad (25) according to the type of sheet. Note that the assigned numbers do not limit the configuration of the present invention.

(e) Operation Based on the above-mentioned configuration, the regulating plates (7, 9) are moved in accordance with the sheet size to move the sheets (S) loaded on the middle plate (36) of the sheet storage device (1) in the width direction or When the movement in the rear direction is restricted by the restriction plate (7, 9), the restriction plate (7, 9)
9), the middle plate (36) moves, and the middle plate (36)
By this movement, the angle of approach of the sheets (S) loaded on the intermediate plate (36) into the separation pad (25) is changed in accordance with the type of sheet. The sheets (S) loaded on the middle plate (36) are then transported between the feeding rotary body (19) and the separation pad (25).
) are separated and fed one by one.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

Note that the same parts as those described above are given the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 1 and 2, the cassette 1 included in the sheet feeding device 16 has a shaft 3 fixed to a cassette body 2.
5 rotatably supports the middle plate 3.
A second intermediate plate 36 is disposed in the front part of the shaft 3 and a shaft 3 fixed to the intermediate plate 3
7, and a groove portion 36a is formed approximately in the center of the second intermediate plate 36. This groove 3
The opposite side of 6a is a protruding portion 36b toward the back.

Furthermore, width regulating plates 7 and 9 for regulating the width direction of the sheet S are disposed on the middle plate 3 so as to be movable in the direction of arrow A, and the front portions of these width regulating plates 7 and 9 are arranged in the middle. Plate 3 and second middle plate 3
It is inserted between 6.

Since this embodiment has the above configuration, A3, B4
, A4, B5, etc., the operator places the sheet S on the middle plate 3, and presses the width regulating plate 7.
9 and the rear end regulating plate 13 to regulate the movement of the sheet in the width direction and rearward direction. At this time, the tip of the width regulating plate 7.9 is spaced apart from the groove 36a of the second intermediate plate 36 (see FIG. 1). Then, when the cassette 1 is installed in the image forming apparatus main body, the bottom of the cassette 1. The lid 30 is inserted into the opened opening (not shown), and the lifter 30 pushes up the middle plate 3 by the urging force of the spring 32 (see FIG. 2). As a result, the sheets S loaded on the intermediate plate 3
is pressed against the paper feed roller 19 or the auxiliary roller 21. At this time, θ, which will be described later, is about 2O4. Furthermore,
When a start key (not shown) is pressed in this state, the paper feed roller 19 starts rotating, and the sheets S stored in the cassette 1 are separated by the roller 19 and the separation pad 25.
The sheets are separated one by one and only the uppermost sheet S is fed. Then, the sheet S is guided to a pair of registration rollers 27 by upper and lower guides 22 and 23, and synchronously conveyed downstream by the pair of rollers 27 that start rotating at a predetermined timing.
In addition, when feeding special sheets (for example, envelopes), the operator loads the envelopes S on the middle plate 3 of the cassette 1,
The envelope S is moved by moving the width regulating plates 7 and 9 and the rear end regulating plate 13.
1 in the width direction and backward direction. At this time, the tip of the width regulating plate 7.9 comes into contact with the bottom protrusion 36b of the groove 36a of the second intermediate plate 36 and rotates the second width plate 36 clockwise (see Fig. 3). As a result, the approach angle θ of the envelope Sl to the separation pad 25 (the angle formed by the tangent between the separation pad and the roller 19 and the sheet feeding direction line) becomes smaller, and the frictional resistance between the separation bat 25 and the envelope S1 becomes smaller. Become. That is, as the angle O between the sheet tip and the separation pad becomes smaller, the component force directed toward the separation pad also becomes smaller.

Then, the envelope S is fed by the same operation as described above. At this time, θ is about 156 to about 08. However, the angle is not limited to 15°.

Further, as another embodiment, a case where the middle plate 39 moves up and down and rotates will be explained along with FIGS. 4 to 6. In addition,
The same parts as those described above are designated by the same reference numerals, and their explanation will be omitted.

As shown in FIG.
It is equipped with a 4° shaft supported so as to be movable in the vertical direction.
An intermediate plate 39 is rotatably supported on the shaft 40. Further, a guide member 41 is disposed approximately in the center of the cassette body 2, and the guide member 41 includes stepped portions 41a, 41a opposing each other in the sheet width direction. Furthermore, a guide groove 41b is carved in the central part of the guide member 41 from the step portions 41a, 41a, and the guide groove 41 restricts the movement of the sheet S in the width direction, and the movement of the sheet S in the width direction is restricted by a spring (not shown). The width regulating plates 7'', 9'' which are biased in the direction are guided in the six directions of the arrows. Furthermore, in the case where these width regulating plates 7″ and 9″ are located at the step portions 41a and 41a, and in the case where they are located approximately at the center of the guide member 41,
The vertical positions of the width regulating plates 7'' and 9'' are different. Furthermore, the tip portions of these regulating plates 7'' and 9'' are fitted onto the shaft 40, and the shaft 40 and the middle plate 39 are raised and lowered depending on the vertical position of these width regulating plates 79''.

When conveying a normal sheet S, the width regulating plate 7''
, 9'' are located on the step portions 41.a, 41a (the fourth
(see figure), thereby placing the shaft 40 and middle plate 39 in a high position (
5), and the approach angle of the sheet S of the intermediate plate 39 to the separation pad 25 is a normal angle (approximately 20°). Then, the sheets S are separated and fed one by one by the same operation as described above. When feeding ordinary sheets, the approach angle θ must be approximately 20° because separation will not be possible unless the sheet is at a certain angle. However, it is not limited to 20''.

In addition, when feeding the envelope S1, the operator moves the width regulating plates 7'' and 9'' to approximately the center of the guide member 41 to regulate the movement of the envelope S1 in the width direction, and also moves the rear end regulating plate 1
3 to restrict the backward movement of the envelope S. At this time, if the vertical position of the width regulating plates 7'' and 9'' is normal,
The shaft 40 and the middle plate 39 are also lowered to a lower position (see FIG. 6) than when feeding the shaft S. As a result, middle plate 3
The angle of approach of the envelopes S1 stacked on the separation pad 25 becomes smaller, and the frictional resistance is also reduced.

As a result, the envelope S is fed by the same operation as described above.

Further, as another example, a case where the rear end side of the middle plate 42 is pushed down will be described along FIG. 7.

The cassette 1'' has a middle plate 42 whose rear end 42a is bent upward, and a bulge 42a is formed approximately at the center of the rear end of the middle plate 42.

The tips 7''a, 9''a of the width regulating plates 7'', 9'', which regulate the movement of the sheet S in the width direction, are bent downward, and these tips 7'''a, '9
``'a is engaged with the rear end of the middle plate 42, and the middle plate 4
2 is designed to rotate around the engaging portion.

When feeding a normal sheet S, the operator moves the width regulating plates 7"', 9"' and the trailing end regulating plate 13 to regulate the movement of the sheet S in the width direction and rearward direction. At this time, the width regulating plates 7'', 9'' are the bulges 42a of the middle plate 42.
The intermediate plate 42 is located at the normal position, and the sheets S stacked on the intermediate plate 42 are fed by the same operation as described above.

In addition, when feeding the envelope Sl, the width regulating plates 7″′, 9″
' and the trailing end regulating plate 13 are moved to restrict movement of the envelope in the width direction and rearward direction. At this time, width regulating plates 7″′, 9″
' comes into contact with the bulge 42a and pushes down the bulge 42a. As a result, the middle plate 42 rotates about the retaining portion between the rear end 42b and the tips 7''a and 9''a of the width regulating plate 7tr/91// as a fulcrum, and rotates the tip upwardly. Moving. The envelopes loaded on the middle plate 42 are fed by the same operation described above by reducing the angle of approach to the separation pad 25 to reduce the l"J friction resistance9. In the above embodiment, Although the middle plate 36 is configured to move in conjunction with the width regulating plate 7.9, it is not limited to this, and may be configured to move in conjunction with the rear end regulating plate 13 (see FIG. 8). ).

In addition, although the above explanation was about a removable cassette,
The present invention is not limited to this. For example, the device may include a storage device built into the device body.

Further, in the present invention, the middle plate is moved by a regulating plate depending on the size of the sheet, or the middle plate may be moved by a lever means 40 or the like that is operated in the case of a special sheet such as an envelope. (See Figure 9) (G) As described in detail, according to the present invention, the approach angle of the sheets loaded on the intermediate plate to the separation pad is changed in accordance with the type of the sheet. Therefore, by reducing the angle of entry of the special sheet such as an envelope into the separation pad, the frictional resistance can be reduced and the special sheet can be fed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a seat storage device according to the present invention. Moreover, FIG. 2 shows the C-! according to the present invention. - It is a front sectional view showing a feeding device. Furthermore, FIG. 3 is a front sectional view showing the operation of the present invention. 4 to 9 are diagrams showing other embodiments of the present invention. Moreover, FIG. 10 to FIG. 12 are diagrams showing conventional examples. 7, 9. 7', 9'7" 9
"7"'... Regulation plate, 16... Sheet feeding device; n19... Feeding rotary body, 25... Separation butt 3', 36... Middle plate 36b, 41a, 4
2a... Transportation means S... Seat 9 ″′

Claims (1)

[Scope of Claims] 1. It has an intermediate plate loaded with a large number of sheets and movably supported, and a regulating plate that restricts the movement of the sheets stacked on the intermediate plate in the width direction or rearward direction. A sheet feeding device comprising a sheet storage device, a feeding rotating body that feeds the sheets loaded on the intermediate plate, and a separation pad that separates the sheets fed by the feeding rotating body one by one. A sheet characterized by comprising a moving means for moving the middle plate in the vertical direction so as to change the approach angle of the sheets loaded on the middle plate to the separation pad according to the type of sheet. Feeding device.