JPH0353217B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Purpose of the Invention (Field of Industrial Application) This invention is a copier, a printer, etc., in which sheets such as transfer paper are taken out one by one from a cassette containing a large number of sheets stacked one on top of the other. The present invention relates to a paper feeding device, and particularly to a paper feeding device that makes it easy to attach and detach a cassette.

(Prior art and problems to be solved) A large number of sheet materials are stored in a cassette with an open top surface, the sheets are elastically biased from below to the open side, and this cassette is inserted into the main body of a copying machine or the like. A paper feeding device that, when installed, presses a paper feeding roller disposed on the main body side to the sheet material on the uppermost surface in the cassette, and drives the roller to feed the sheet material one by one to the main body side. has traditionally been commonly used.

In this type of paper feeding device, the paper feeding roller located on the main body side of the copying machine etc. is always in pressure contact with the sheet material held relatively loosely on the top surface of the cassette, so the paper feeding device is fed when not in operation. Even if the driving force to the paper rollers is cut off, when a cassette is removed from the main body for some reason, the cassette must be pulled out against the large rotational torque required to rotate the paper feed roller. There was a risk that the innermost sheet material and several sheets adjacent thereto would be displaced from their predetermined positions in the cassette or damaged.

To avoid such problems, when inserting or removing the cassette into or out of the copying machine main body, insert or remove the cassette in a direction that prevents the sheet material inside the cassette from coming into contact with the paper feed rollers inside the main body. Either rotate the cassette slightly at the position so that the sheet material comes into contact with the paper feed rollers, or insert/remove the cassette with the paper feed rollers located on the main body side released, and then insert/remove the cassette until the cassette is in the correct position. The only option was to configure the paper feed roller so that it would come into pressure contact with the sheet material inside the cassette when it was carried out.

However, if the former configuration is used, a part of the cassette will require a swingable space inside the main body near the part where the paper feed roller is arranged, making it difficult to directly copy or print. In order to take up unnecessary space, the main body becomes larger, and after the cassette is completely attached to the main body, it has to be set in a fixed position, which makes the operation difficult.

In addition, in the case of the latter configuration, the paper feed roller is equipped with a mechanism for driving it.
It is obvious that configuring these parts in an active state complicates the configuration and lowers reliability, which is undesirable.

The present invention has been made in view of the above-mentioned current situation, and it is possible to separate the shaft supporting the paper feed roller from the drive shaft at any time in a conventionally well-known paper feed mechanism on the main body side that includes a paper feed roller. In addition, by rotatably supporting the paper feed roller supported by the shaft, the main body can be easily constructed without requiring any special additional mechanism. To provide a highly reliable paper feeding device that allows cassettes to be inserted and removed in a single plane, without increasing the commercial space of the main body of a copying machine, etc., and that is easy to operate. This is the purpose.

(2) Structure of the invention (technical means for solving the problem, and its operation) In order to achieve the above object, the present invention stores and stores sheet materials P in a paper feeder of an image forming apparatus. , B2, and a plurality of sheet feeding means 4a, 4b, 4c that supply sheet materials by pressing and rotating the sheet materials stored in the loading means.
a drive shaft 3 for supporting the paper feeding means and transmitting a driving force from a drive source to the paper feeding means; and a drive shaft 3 for releasing the connection between the drive source and the drive shaft to free the drive shaft. The apparatus is characterized in that it includes a release means 5 and means 7, 8, 9, and 10 for supporting the sheet feeding means so as to be rotatable in a fixed amount relative to the drive shaft.

With this configuration, the cassette can be attached to and removed from the main body of the apparatus very easily without disturbing the sheet material, without the need for any special accessory mechanism or extra space for attaching and detaching the cassette.

(Explanation of Embodiment) In FIG. 1, symbols B1 and B2 are members forming a cassette mounting section formed on the side of an image forming apparatus such as a copying machine or a printer, and there is a double-headed arrow A between the two members.
The cassette is inserted and removed in this direction.

The figure shows the cassette being installed at the paper feeding position within the apparatus, and in this position the shaft 3 disposed on the apparatus side is assumed to be near the leading end of the sheet material P in the cassette.

The sheet material P is biased toward the open top surface of the cassette by a spring (not shown) disposed at the bottom of the cassette, and separated by separating claws 2a and 2b that regulate the sheet material P. This is different from known cassettes in that the topmost position of P is limited, so that regardless of the amount of sheet material P, the vertical position of the topmost sheet material is maintained constant. Since there is no such thing, the details will be omitted.

A suitable number (three in the illustrated embodiment) of paper feed rollers 4a, 4b, 4c are mounted on the shaft 3 so as to be rotatable with respect to the shaft. An electromagnetic clutch 5 is disposed at the end, and a driving force from a drive source (not shown) is input through a gear 6, and the driving force is transmitted to the shaft 3 by opening and closing the electromagnetic clutch 5. or the shaft 3 shall be made free.

As mentioned above, each paper feed roller 4a, 4b, 4c is rotatably supported on the shaft 3, and as shown in FIG. A recess 7 is formed, and a pin 8 fixed to the shaft 3 is located in the recess 7. Although not shown, the other paper feed rollers 4b and 4c have a similar configuration, and each paper feed roller is also prevented from being biased in the axial direction of the shaft 3 by appropriate thrust stop means. It's summery.

In the above configuration, in order to pull out the cassette from the main body, the electromagnetic clutch 5 is released in response to a sequence signal (not shown), and the cassette is moved in the direction of arrow B while no driving force is applied to the shaft 3. do. In this case, the shaft 3, and therefore the paper feed rollers 4a, 4b, and 4c, are in a state where they can rotate freely and easily, so even if these paper feed rollers are in contact with the sheet material, they will not disturb the sheet material. You can pull out the cassette without any trouble.

Also, when moving to pull out the cassette, as shown in Figure 3, there is a slight gap between both sides of the cassette and parts B1 and B2 on the main body side, as shown by symbol G. Since it is normal, it is difficult to pull out the cassette accurately in one direction in the direction of the arrow B mentioned above, and it tends to rotate as shown by the symbol D in FIGS. 1 and 3 (or in the opposite direction). I can't escape it.

If such a tendency to rotate the cassette occurs, the paper feeding rollers will act to twist the uppermost sheet material, which may cause disturbances in the sheet material.

In contrast, in the present invention, the paper feed roller is rotatable by a small amount on the shaft 3, so that the above-mentioned situation can be coped with.

As mentioned above, the pin 8 provided on the shaft 3 presses the recess 7 formed in the paper feed roller 4a (same for other paper feed rollers).
Since they are loosely engaged, the paper feed roller 4a can rotate in any direction with respect to the shaft 3 within the range of the recess 7.

As shown in Figure 4, if the cassette tends to rotate in the direction of arrow D in the figure when it is pulled out, the sheet material P inside also tends to rotate from the position of the solid line in the figure in the direction of the dashed-dotted line. As a result, torques as shown by E, F, and G in the figure are applied to each paper feed roller 4a, 4b, and 4c.

On the other hand, as mentioned above, each paper feed roller can rotate in any direction within a certain range, so the paper feed rollers will rotate according to the deflection of the sheet material according to the above torque. Since it rotates, the sheet material will not be disturbed.

The same applies if the cassette is deflected in the direction opposite to arrow D.

When loading the cassette into the main body, by keeping the electromagnetic clutch 5 in the disengaged position, even if the sheet material being loaded comes into contact with the paper feed roller, the traveling direction of the sheet material being loaded will be aligned with the shaft 3. Even if they are not exactly perpendicular to the paper feed roller, the shaft 3 and the paper feed roller rotate easily, and the paper feed roller can rotate freely relative to the shaft 3, so that the sheet material is not disturbed or damaged. It can be easily set in a predetermined position without any occurrence.

FIG. 5 shows another embodiment in which a paper feed roller is rotatably mounted on the shaft 3, in which a paper feed roller 4a (another paper feed roller 4a) is rotatably mounted on the shaft 3. A pin 10 is attached to the side surface of the paper roller (the same applies to the paper roller), and the pin is located in a recess 9a of a collar 9 fixed to the shaft 3.

(3) Effect of the invention As explained above, according to the present invention, in an image forming apparatus, sheet materials such as transfer paper are stacked and stored, and the sheets are fed by a paper feed roller that elastically contacts the sheet materials. When sheets are sequentially conveyed into the image forming apparatus, the drive of the paper feed roller is connected as necessary from its drive source when attaching and removing the cassette that stores the sheet materials to and from the image forming apparatus. In addition to being able to shut off the feed roller, the paper feed roller is rotatable in any direction relative to the shaft that supports it, so when the cassette is attached to or removed from the main body of the apparatus, it is possible to
The cassette can be smoothly attached and detached by simply inserting and removing the cassette within a single plane, and does not require any special accessory mechanism or extra space for attaching and detaching the cassette.

In addition, when attaching or removing a cassette, the paper feed roller follows the direction of movement of the cassette, and therefore the movement and displacement of the sheet material stored therein, so the sheet material is Disturbances and damage can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the paper feeder according to the present invention, FIG. 2 is a perspective view showing the structure of the paper feed roller, and FIG. 3 is a perspective view showing the structure of the cassette, the stored sheet materials, and the paper feed roller. FIG. 4 is an explanatory diagram showing the relationship between the paper feed roller and the sheet material when the cassette is moved, and FIG. 5 is a perspective view showing another embodiment of the paper feed roller. . 1...cassette, 2a, 2b...separation claw, 3...
...shaft, 4a, 4b, 4c... paper feed roller, 5... electromagnetic clutch, 6... gear, 7, 9a... recess,
8, 10...Pin.

Claims (1)

[Claims] 1. The sheet material P is loaded and stored, and the image forming apparatus B
1, a loading means 1 detachably attached to B2;
A plurality of sheet feeding means 4a, 4b, 4c supplying sheet materials by pressing and rotating against the sheet materials stored in the stacking means, supporting the sheet feeding means and providing a driving source for the sheet feeding means a drive shaft 3 for transmitting a driving force from the drive shaft; a release means 5 for releasing the drive shaft by disengaging the drive source from the drive shaft; and a release means 5 for freeing the drive shaft by disengaging the drive source from the drive shaft; Means 7, 8; 9, 1 for supporting reciprocatingly by a certain amount
A paper feeding device characterized by comprising: 0.