JPH01181633A - Paper feeding device - Google Patents

Abstract

PURPOSE:To improve interchangeability by forming a sending roller, a reversing roller and a paper feed roller in a same form, and removably fitting recessed portions thereof provided on respective end faces to projections on body side. CONSTITUTION:A sending roller 1, a reversing roller 2 and a paper feed roller 3 are made to be in a same form having cross-shaped recesses at their ends on. A cross-shaped projection on a one way clutch coupling 5 side, projections on a coupling 4 side and a coupling 6 side, which are respectively fixed to center shafts 8, 7, 9, are inserted in the recesses. Three kinds of rollers 1, 2, 3, therefore, are made to be in a same form, but made to be possible to be mounted detachably to respective shaft coupling 5, 4, 6, and further interchangeability is improved broadly and parts cost is reduced.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides an image forming apparatus such as a copying machine, a printer, etc.
The present invention relates to a paper feeding device that sequentially feeds sheet materials on a mounting means into an apparatus main body one by one.

(Prior Art) Conventionally, the above-mentioned paper ? It is known that claws are provided at both optical ends of the paper on the L tray, and the paper is separated one by one by the claws while the paper is sent out by a paper feed roller. However, there is a problem in that multiple sheets of paper may be fed out without being separated one by one. Also,
The problem with the above device is that when separating thick paper of approximately 100 g/m2 or more using the aforementioned claws, the leading edge of the paper may fold or the paper may get caught in the claws, resulting in the paper not being fed at all. It also has Furthermore, in the above-mentioned apparatus, since the paper is separated by claws at both ends of the paper, the paper feeding resistance at this portion increases, and a large conveying force is required of the paper feeding roller.

Therefore, the above-mentioned apparatus requires a paper feed roller at an appropriate position for each paper size, which increases the number of paper feed rollers, resulting in a problem that the apparatus becomes complicated.

Therefore, a paper feeding device that solves the above-mentioned problem is equipped with a feeding roller that rotates in the paper feeding direction and a reversing roller that presses this feeding roller and applies rotational torque in the opposite direction to the paper feeding direction. An apparatus is known in which even if multiple sheets of paper are to be sent out from a paper loading table, only one sheet is sent into the main body of the apparatus using a reversing roller. According to this device, since the above-mentioned claws are not used, it is possible to feed even thick paper of 100 g/m2 or more, and the effect of preventing double feeding is sufficient, and the number of paper feed rollers is also reduced. can be reduced.

, Such a conventional paper feed bag δ will be specifically explained based on FIGS. 6 and 7. That is, in FIGS. 6 and 7, the paper on the paper table 106 is fed by the paper feed roller 103 between the feed roller 101 and the reversing roller 102, and the downstream roller pair 104 and 105 transfers the paper to an image (not shown). It is sent to the formation area. This reversing roller 102 is given a rotational torque in the opposite direction by a torque limiter 112, and the feeding roller 101. When a plurality of sheets of paper are about to enter between the reversing rollers 102, they are rotated in the opposite direction and the sheets other than those in contact with the feed roller 101 are returned to the feed roller 103 side to prevent double feeding. Further, a one-way clutch 113 is attached to the feeding roller 101, and when the paper that has passed between the feeding roller 101 and the reversing roller 102 is gripped by a downstream roller pair 104, 105 and pulled, the roller pair It is customary to prevent tension between the two. Further, the paper feed roller 103 is connected to the feed roller 101 by a gear 114 and a connecting means, and rotates synchronously.

However, normally the reversing roller 102. The shapes of the feed roller 101 and paper feed roller 103 are designed to suit each configuration, and three types of rollers are used.

(Problems to be Solved by the Invention) However, in such a conventional example, the feeding roller 10
1. Since the surfaces of the reversing roller 102 and the paper feed roller 103 must maintain a predetermined coefficient of friction, they must be replaced periodically after a predetermined number of sheets have been passed.Especially, the above-mentioned rollers are used in high-speed image forming apparatuses. In some cases, the frequency of replacement becomes very high, and maintenance costs also increase.

As a countermeasure to this problem, it is possible to improve the lifespan of the roller itself.
There are technical limits. Therefore, as mentioned above, it is impossible to avoid problems such as the complexity of replacement due to having three types of rollers, or the increase in parts unit cost and management cost.

Therefore, the present invention was made to solve the above-mentioned problems of the conventional example, and its purpose is to improve the compatibility and reliability of rollers, and to reduce the unit cost of parts9 parts management cost. The object of the present invention is to provide a paper feeding device that achieves the following objectives.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a feeding roller that rotates in the paper feeding direction, and a feeding roller that is in pressure contact with the roller and rotates in the opposite direction to the paper feeding direction. A reversing roller to which rotational torque is applied;
In a paper feeding device comprising a paper feeding roller that feeds paper between the feeding roller and a reversing roller, the feeding roller;
A feature is that the reversing roller and the paper feeding roller are configured in the same shape.

(Function) In the present invention having the above configuration, the feeding roller, the reversing roller, and the paper feeding roller are configured to have the same shape, so that three types of rollers can be standardized as 〒 types of rollers.

(Example) The present invention will be explained below based on the illustrated example. 1st
1 and 2 show a first embodiment of the present invention. In FIG. 1, l is a feeding roller that rotates in the paper feeding direction, and 2 is in pressure contact with the feeding roller 1 in a direction opposite to the paper feeding direction. rotational torque is applied via the torque limiter 11. Reference numeral 3 denotes a paper feed roller that feeds paper into the nip between the feed roller 1 and the reversing roller 2. Further, the feeding roller 1 is given rotational force by the feeding roller shaft 8 driven by the clutch 12 via the one-way clutch 5, and the reversing roller 2
engages with the joint 4 fixed to the reversing roller shaft 7 via the torque limiter 11 and rotates. Then, paper feed roller 3
rotates from the feed roller shaft 8 to the paper feed roller shaft 9 together with the joint 6 via a gear.

In the above explanation, the names and numbers of the feed roller 1, reverse rotation roller 2, and paper feed roller 3 have been changed in order to explain them in comparison with the conventional example, but as can be understood by referring to FIG. These three members are configured to have exactly the same shape.

Next, the end shape of the reversing roller 3 will be explained in more detail in the second section.
This will be explained with a diagram. In the figure, a cross-shaped recess 3a as shown in the figure is formed at the end of the reversing roller 3, and a protrusion 4a on the joint 4 side fits into this recess 3a to drive the reversing roller shaft 7. Communicate. Regarding the other rollers 1 and 2,
The convex portion of the one-way clutch 5 and the convex portion on the joint 6 side fit into the concave portion on the roller side, so that they rotate together. It is desirable that the relationship between the concave portion and the convex portion be formed in such a shape that there is as little backlash as possible in order to transmit the driving force smoothly.

As described above, by forming a concave portion at the end of each roller and fitting it with a convex portion provided on a member on the paper feeder main body side, each roller can be attached to and detached from the central shaft that supports the roller. Due to the flexible structure, each roller can be easily replaced.

FIG. 3 shows a second embodiment of the present invention, and the same members as in the first embodiment will be described with the same reference numerals. In this embodiment, a convex portion 3b is formed at the other end of the concave portion 3a at the end of the reversing roller 3 shown in FIG.
Although not shown here, for b, it may be configured to fit into a recess provided on the paper feeder main body side.By providing the protrusion 3a and the recess 3b at both ends in this way, for example, the reversing roller Rubber-like friction member 15 covering the outer periphery of 3
If there is a directionality of polishing and it is desired to specify the directionality by determining where the roller is to be used among the three locations, this can be specified by the direction of the unevenness, and incorrect attachment can be prevented. Further, if the directionality of the polishing described above is arbitrary, a convex portion or a concave portion may be provided at both ends of the reversing roller.

Although FIG. 3 describes the reversing roller 3, the present invention can also be applied to the feeding roller 1 and the paper feeding roller 3 since each roller has the same shape.

FIGS. 4 and 5 show a third embodiment of the present invention, and the same members as in the first embodiment will be described with the same reference numerals. FIG. 4 shows a hole formed in a part of the core material 17 when the aforementioned feeding roller 1 is composed of an elastic member 16 such as rubber and a core material 17 to which this elastic member 16 is attached. An example is shown in which the locking member 28 is fitted into the shaft 8 and the elasticity of the elastic member 16 is applied to prevent the shaft 8 from being pulled out in the thrust direction. That is, when the feeding roller l is inserted into the shaft 8 from the left side in the figure, the locking member 2 as a locking member is
Until the tip 28a of the shaft 8 falls into the groove 29a of the shaft 8, due to the elasticity of the elastic member 26, it moves on the outer peripheral surface of the shaft 8 while being lifted upward in the figure.
It fell to a, and the withdrawal was stopped. Figure 5 shows the lock member 3
0 is arranged approximately at the center of the feeding roller l.

As described above, by providing the locking member 20 inside the feeding roller l as shown in FIGS. 4 and 5, the feeding roller l can be inserted simply without using the thrust stopper 30 shown in FIG. Since it also has an afl to prevent removal in the thrust direction, the replaceability of the roller is further improved.

Note 1. In FIGS. 4 and 5, an example in which the present invention is applied to the feed roller 1 has been described, but since each roller has the same shape, the present invention can also be applied to the reversing roller 2 and the paper feed roller 3.

(Effects of the Invention) As described above, according to the present invention, since the feeding roller, the reversing roller, and the paper feeding roller are all configured to have the same shape, the replaceability is greatly improved. This is particularly effective for high-speed printers that are frequently replaced. Also,
Since there is only one type of roller, parts management costs are reduced, and the structure of the roller itself is simplified, so that the unit cost of parts can be reduced.

Furthermore, by improving replaceability, it is possible to provide a highly reliable feeding device.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing a first embodiment of the present invention, Fig. 2 is a perspective view of essential parts of the same embodiment, Fig. 3 is a sectional view showing a second embodiment of the invention, Fig. 4 Ca) is a sectional view showing the third embodiment of the present invention, FIG. 4(b) is a side view of FIG. 4(a), and FIG.
a) is a cross-sectional view showing a modification of the same embodiment, FIG. 5(b) is a side view of FIG. 5(a), FIG. 6 is a schematic diagram showing the conventional feeding device, and FIG. 7 is the same. FIG. 2 is a configuration diagram of a conventional example. Explanation of symbols l... Feeding roller 2... Reverse roller 3...
・Paper feed roller 3a...concavity 3b...convexity
4...Coupling 5...One-way clutch

Claims (4)

[Claims] (1) A feeding roller that rotates in the paper feeding direction, a reversing roller that is in pressure contact with the roller and applying rotational torque in the opposite direction to the paper feeding direction, and paper is placed between the feeding roller and the reversing roller. What is claimed is: 1. A paper feeding device comprising a paper feeding roller that feeds paper, wherein the feeding roller, the reversing roller, and the paper feeding roller have the same shape. (2) The paper feeding device according to claim 1, wherein each of the rollers is removable from a central shaft that supports each roller. (3) A convex portion or a concave portion is formed on at least one end surface of each of the rollers, and the convex portion or the concave portion is configured to fit into a concave portion or a convex portion on the device main body side. Paper feeding device according to scope 1. (4) Each of the rollers is composed of a cylindrical core material and an elastic member attached to the outer peripheral surface thereof, and includes a locking member protruding between the rotation center holes of the core material. A paper feeding device according to claim 1.