JPS6218594Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a paper reversing device for a device in a copying machine, printing machine, etc., which reverses the paper midway through the paper transport path. The present invention relates to a paper reversing device for reversing sheets.

In this type of device, paper sent along a conveyance path from a copying machine, a printing machine, etc. is introduced into a switchback section of a reversing device by a carry-in means, and the conveyance means provided in the switchback section is corrected. The paper is further fed into the switchback section by rotating the paper, the paper is reversely fed by reversing the conveyance means, and the paper is reversed by being returned to the conveyance path by the unloading means. However, in such a reversing device that reverses the paper by rotating the transport means in the forward and reverse directions, it is very difficult to carry in the next sheet while the transport means is rotating in the reverse direction. Therefore, such a reversing device is not suitable as a sheet reversing device for high-speed copying machines and the like.

A reversing device disclosed in US Pat. No. 3,944,212 has been proposed as a device compatible with such high-speed copying machines and the like. This device is shown schematically in FIG. This reversing device includes a switchback part a,
three rollers 1, 2, and 3 that act as a carry-in means for carrying paper into the switchback section and a carry-out means for carrying out the paper from the switchback section;
A non-perfect circular roller 4 that rotates approximately once in the paper reverse feeding direction, which acts as a conveying means to reversely feed the paper carried in by the rollers 1 and 2 and carried out by the rollers 2 and 3, and a non-perfect circular roller 4 that is driven by this non-perfect circular roller. A driven roller 5 is provided, and detection means 6 and 7 are provided for detecting that paper is introduced into the switchback section.

In the above-mentioned reversing device, the paper sent from a copying machine, printing machine, etc. along a conveyance path (not shown) is sandwiched between rollers 1 and 2, which act as carrying means, and is transferred into the switchback section a. will be introduced in
At this time, since the non-round roller 4 is held at the position shown in the figure, the paper reaches the switchback part a without being restrained by the rollers 4 and 5, and this is detected by the detection means 6 and 7. In response to the detection signal, the non-perfect round roller 4 rotates approximately one rotation in the direction of the arrow to reversely feed the paper. This paper is sandwiched between rollers 2 and 3 which act as a carrying-out means, and carried out to the above-mentioned conveyance path.

The above-mentioned reversing device rotates the non-perfect round roller in the paper reverse direction immediately after the paper reaches the switchback section to reversely transport the paper and carry it out, so that the paper can be reversed at high speed. However, in this reversing device, if the paper is curled or folded, or if there are variations in paper spacing during continuous reversal and the reversal timing is not correct, the sheet to be reversed and reversed is
If the trailing edge of the paper is not caught between the rollers 1 and 3 and hits the side of the pair of carry-in rollers 1 and 2, a jam or the like often occurs.
Furthermore, the above-mentioned reversing device has a complicated structure because it is configured to use an electromagnetic clutch to switch between two drive sources in order to drive the rollers 4 and 5.

The present invention attempts to eliminate the drawbacks of the conventional reversing device as described above, and is capable of reliably and reliable reversing and conveying without skewing or jamming, and also has two systems as described above. A coil spring is provided that is charged by the forward rotation of the forward/reverse rotation roller, and this coil spring causes the forward/reverse rotation roller to reverse rotation without using a complicated mechanism such as switching the drive source by an electromagnetic clutch. Thus, the present invention aims to provide a reversing device in which the drive mechanism for the forward and reverse rotation rollers is simplified.

That is, the reversing device according to the present invention includes a carry-in means for introducing the paper into the switchback part, a transport means for transporting the paper reversely after being introduced into the switchback part, and a transport means for transporting the paper reversely transported by the transport means. In the paper reversing device, the conveyance means has a forward and reverse roller 13 that rotates forward and backward, and a driven roller 14 that follows the forward and reverse roller 13, and a rotation shaft 26 of the forward and reverse roller 13. The one-way clutch 29 and the coil spring 31 that is charged by the normal rotation of the forward/reverse rotation roller 13
It is characterized by having the following.

Hereinafter, the present invention will be explained with reference to the drawings. Second
The figure shows an embodiment of the invention. In the figure, a indicates a switchback portion, and 8, 9, and 10 indicate triple rollers that are constantly rotating and serve as loading means and unloading means, similar to rollers 1, 2, and 3 shown in FIG. In order to detect the paper carried into the carry-in rollers 1 and 2, paper detection means 11 and 12 for detecting the trailing edge of the paper are arranged upstream of the rollers 8 and 9. The conveyance means for reversely conveying the paper introduced into the switchback part a by the carry-in rollers 8 and 9 normally consists of a pair of rollers facing each other with a gap between them.
In the illustrated embodiment, the non-perfect circular roller 13 rotates in forward and reverse directions.
and a driven roller 14 that follows this.
In the figure, 15 indicates paper. The paper 15 is sandwiched between a pair of carry-in rollers 8, 9 of triple rollers 8, 9, 10 and sent to a pair of reversing rollers consisting of a non-perfect round roller 13 and a driven roller 14. The trailing edge of the paper 15 is detected by the detection means 11 and 12, and after a certain period of time the paper 15 is
Before the rear end passes through the pair of rollers 8 and 9, the non-perfect round roller 13 starts rotating in the feeding direction (direction A), pinches the paper 15 with the driven roller 14, and further feeds the paper 15. Therefore, since the paper 15 is sandwiched between at least one of the pair of rollers 8 and 9 and the pair of rollers 13 and 14, the paper is fed without being skewed.

Since the driven roller 14 is moved toward the non-round roller 13 by a spring or the like, large pressure is not generated due to the rotation of the non-round roller 13. Therefore, the impact caused by contact with the roller 13 can be reduced, and the effects on the paper, such as paper folding due to large pressure, can be reduced. Further, the driven roller 14 may be made of foamed urethane or the like with low hardness. A similar effect can be obtained. Non-perfect round roller 1
After the start of step 3, the non-perfect circular roller 13 rotates in the opposite direction (rotates in the direction B) before the rear end of the paper 15 passes through the pair of rollers 13 and 14 after a certain period of time has elapsed. As a result, the rear end of the paper 15 is sandwiched between the pair of delivery rollers 9 and 10 and sent out. At this time as well, the paper 15 is sandwiched between at least one of the pair of rollers 13 and 14 or the pair of rollers 9 and 10, and skewing of the paper is prevented.

According to the present invention, in the reversing device of the above type, between the pair of rollers 8, 9 serving as a carrying means and the switchback section a, the sheet is allowed to be conveyed from the pair of rollers 8, 9 to the switchback section a; A flapper 16 is provided which prevents the sheet from being fed back from the switchback section towards the roller pair 8,9. In the illustrated embodiment, the flapper 16 is loosely fitted onto the roller 9, as shown in FIG. 3, and forms a paper carry-in side passage 17 between it and the guide plate 19a on the paper carry-in side. and a guide plate 19b on the paper exit side.
A paper discharge side passage 18 is formed between the two. This flapper 16 is caused by its own weight or by a spring or the like to cause its tip 16 ₁ to touch the guide plate 1 on the carry-in side.
It is designed to lightly abut against 9a.

Therefore, when reversing the paper, the paper 15 is carried in by the pair of carry-in rollers 8 and 9, passes through the carry-in passage 17 of the flapper 16, and the rear end of the paper passes through the tip ₁₆₁ of the flapper 16 and passes through the pair of rollers. 13 and 14, the non-round roller 13 starts to rotate in the opposite direction. As a result, the trailing edge of the sheet 15 passes through the output side 18 of the flapper 16 and reaches the pair of output rollers 9, 14.
10 and sent out. At this time, paper 1
The rear end of the roller 5 is reliably guided to a pair of discharge rollers 9 and 10 by a flapper 16. Here, the tip ₁₆₁ of the flapper 16 lightly contacts the carry-in guide plate 19 due to its own weight or a spring, but the rear end of the paper 15 after being turned over may hit the tip of the flapper 16 and jam. Therefore, as shown in FIG.
By providing a recessed portion in a part of the flap 9a, it is preferable to sink the tip ₁₆₁ of the flapper, thereby preventing the tip ₁₆₁ of the flapper and the rear end of the paper 15 from colliding after being reversed. .

Next, a mechanism for driving the non-round roller 13 will be explained with reference to FIG. 5. The device shown in FIG. 5 rotates a non-perfect circular roller 13 in forward and reverse directions.
In the figure, 20 is an input gear, 21 is a shaft fixed to the gear 20, 22 is a gear fixed to the shaft 21, 23
is an electromagnetic clutch attached to the shaft 21, 2
4 is a gear fixed to the electromagnetic clutch 23;
5 is an idler gear that meshes with gear 24;
26 is a shaft fixed to the non-perfect circular roller 13;
27 is a gear fixed to the shaft 26 and meshed with the gear 25; 28 is a gear meshed with the gear 22; 29 is an overrunning clutch fixed to the shaft 26 and fixed to the gear 28; 30;
31 is a collar fixed to the shaft 26, and 30 is a collar fixed to the shaft 26.
A coil spring 32 attached to the coil spring 27 is a rotation stopper.

The gear 20 described above is connected to a drive source (not shown) and rotates at a constant speed in the direction A shown in the drawing. After the trailing edge of the paper 15 is detected and the predetermined time elapses, the electromagnetic clutch 23 is activated, and the non-round roller 13 rotates in the direction A. The drive input to the gear 20 is the shaft 21,
It is transmitted through the electromagnetic clutch 23, gears 24, 25, 27, and shaft 26, and rotates the non-round roller 13 in the A direction. At the same time, the shaft 26 rotates the collar 30 fixedly attached to the shaft 26 in the A direction to tighten the coil spring 31. At this time, the overrunning clutch 29 is rotating freely. When the non-perfect round roller 13 starts rotating in the direction A and after the predetermined period of time has elapsed, the electromagnetic clutch 23 is deenergized. As the electromagnetic clutch 23 deenergizes, the shaft 26 attempts to rotate rapidly in the direction B shown in the figure due to the elastic deformation of the coil spring 31 that is tightened during normal rotation. However, if the rotation of the shaft 26 in the B direction becomes faster than the rotation of the gear 28 in the B direction transmitted from the gear 20, the overrunning clutch 29
, the rotation of the shaft 26 in the B direction is caused by the gear 28
corresponds to the rotational speed of Here, non-perfect round roller 1
The input speed to the gear 20 and the gear ratio of the gears 22, 28 and 24, 27 are set so that the conveyance speed of the paper 15 by the driven roller 14 is equal to the loading and unloading speed by the triple rollers 8, 9, and 10. It is set.

The above-mentioned apparatus is configured to control the electromagnetic clutch by detecting the trailing edge of the paper 15. If the electromagnetic clutch is controlled by detecting the leading edge of the paper, then depending on the size of the paper, after the leading edge is detected, the trailing edge of the paper will be detected by the roller pair 8, Since the time it takes to exit the clutch 9 and reach the inverted position is different, the timing for energizing the electromagnetic clutch 19 must be changed for each case, making the control means complicated. However, detecting the trailing edge of paper requires the electromagnetic clutch 19 to be activated at the same timing even for various paper sizes.
The control means is much simpler than the method of detecting the leading edge of the paper and energizing the electromagnetic clutch 19.

Further, as mentioned above, roller pairs 8, 9 and 13, 1
4 and the roller pairs 13, 14 and 9, 10 are smaller than the minimum size of the paper 15 to be used, and the above-mentioned control ensures that the paper 15 cannot be sandwiched between any of the roller pairs during this reversal. This makes it possible to transport paper reliably.

FIG. 6 shows another embodiment of the invention. this is,
A perfectly round roller 33 is used in place of the non-round roller 13 in the embodiment described above, and is made to swing between a position away from the driven roller 14 and a position where it engages with the driven roller 14. However, since its operation is exactly the same as that of the previous embodiment, detailed explanation thereof will be omitted.

As explained above, the reversing device according to the present invention simplifies the structure of the drive mechanism for the forward and reverse rollers by allowing the coil springs charged by the forward and reverse rotations of the forward and reverse rollers to reverse the forward and reverse rollers. can do.

In addition, the flapper is not limited to a reversing device using three rollers, but may be a switchback type reversing device with a pair of loading and unloading rollers.Furthermore, the flapper is attached to the loading side guide plate by a simple method such as its own weight or a spring. The inverting device is in contact with a predetermined pressure, and the rear end of the paper is not directed toward the ejection side due to the stiffness of the paper.
Can be turned in any direction. Further, by providing the flapper, jamming does not occur even if the angle θ (FIG. 2) of the guide plate is increased, so that the reversing portion can be made smaller and has many other advantages.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing the main parts of a conventional paper reversing device, FIG. 2 is a schematic side view similar to FIG. 1 showing an embodiment of the paper reversing device of the present invention, and FIG. 4A and 4B are side views and perspective views showing the tip of the flapper shown in the figure, FIG. 5 is a perspective view showing the drive mechanism of the non-perfect circular roller shown in FIG. The figure is a schematic side view showing another embodiment of the present invention. 8, 9, 10... Triple roller, 11, 12...
Paper detection means, 13... non-perfect circular roller, 14... driven roller, 15... paper, 16... flapper, 1
7... Paper carry-in side passage, 18... Paper carry-out side passage, 19a, 19b... Guide plate.

Claims (1)

[Scope of utility model registration request] Carrying means 8, 9 for introducing paper into the switchback section, transporting means 13, 14 for transporting the paper introduced into the switchback section in reverse, and transporting means for transporting the paper reversely transported by the transporting means 13, 14. 9 and 10, in which the conveying means has a forward and reverse roller 13 that rotates forward and backward, and a driven roller 14 that follows the forward and reverse roller 13, and the rotation of the forward and reverse roller 13. A one-way clutch 29 is attached to the shaft 26, and a coil spring 31 is charged by the normal rotation of the forward/reverse rotation roller 13.
A paper reversing device characterized by being provided with.