JPS6142698B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gripping error detection device for a gripper used in a paper conveyance mechanism of a copying machine or the like.

In a gripper-type paper conveyance device, the leading end portion of the cut paper is gripped by a gripper to convey the paper. FIG. 1 shows an example of the paper gripping section of such a device, in which the paper 1 is held by a backing plate located at the tip of a metal gripper finger (upper claw) 3 rotatably attached to a shaft 2. 3a, and the stepped part (lower claw) 4a of the gripper bed 4, which is also made of metal.
It is designed to be held by the pressing force of the spring 5 between the two. The grippuff fingers 3 are opened and closed, for example, by swinging the operating member 6 by means of a cam and a cam follower (not shown). As shown in FIG. 2, a plurality of grip fingers 3 are attached to one grip bed 4 at predetermined intervals, and when both ends of the grip bed 4 are moved in the direction of the arrow by a conveying chain 8 or the like,
The paper is transported.

Now, in such a gripper type paper conveying device,
If the timing at which the paper is fed to the paper gripping section is incorrect, the leading edge of the paper may go over the grippuff finger 5 as shown in FIG. A grasping error occurs, such as grasping. In conventional paper conveyance devices, when the paper falls off from the paper gripping section due to such a gripping error, a cycle switch or the like is used to time the paper conveyance device's feeding, and a light detection means or a micro switch detects this and prevents the paper from jamming. This prevented paper jams from occurring. However, with such a gripping error detection means, it is possible to immediately detect a gripping error, and if the paper falls off after detection, the device does not stop and the paper gets caught up in the electrostatic drum of the copying machine. Such accidents occurred. For example, if paper gets caught in the electrostatic drum, the surface of the drum may need to be repaired or it may take a lot of time to remove the paper, which has the disadvantage of interfering with copying operations. .

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a gripping error detection device that can detect a gripping error of a paper gripping section at the stage when the paper is gripped.

In the present invention, an electrode is brought into contact with a predetermined position where a gripped sheet of paper should be present in a sheet conveying device, and a gripping error is detected by the presence or absence of electrical continuity.
Achieve the above objectives.

The present invention will be explained in detail with reference to Examples below.

FIG. 4 shows the detection section of the grasping error detection device. The detection unit 10 includes a pair of elongated contacts 11 and 12 having the same shape. These contacts 11 and 12 are arranged parallel to each other with an interval of several mm, and their upper ends are fixed to the end face of an insulating plate 13 arranged horizontally. Insulating board 1
3 is a spring 15 on the inner wall of a casing 14 made of an insulator.
The lower ends 11A and 12A of the contacts 11 and 12 are in pressure contact with an object placed below, and the contacts 11B and 12B protruding from their upper ends are attached above them. It is adapted to come into contact with a pair of contact terminals 16 and 17 arranged therein.

FIG. 5 shows the pressure contact section to which the detection section is attached. The pressure contact part includes a solenoid 21 that operates at a predetermined timing and a moving piece 21 of the solenoid 21.
The actuating member 23 converts the vertical movement of the sensor A into the vertical movement of the detection unit 10 about the fulcrum 22.

Now, this gripping error detection device is provided with two sets of pressure contact parts 20 to which the detection parts 10 are attached. One set of contact terminals 11 and 12 are located on the grippuff fingers located in the center as shown in FIG.
It is arranged so as to be located directly above the points 31 and 32. The other set of contacts 11 and 12 are located near the leading edge of the paper properly gripped and directly above two points 33 and 34 on the gripper bed 4 in the area sandwiched by the two gripper fingers 3. It is arranged like this.

FIG. 6 shows the detection circuit section of this gripping error detection device. Each contact terminal 16 in the pair of detection units 10 is connected at one end to a grounded line 41, 42, and the other contact terminal 17 is connected to a grounded line 41, 42.
2 is a potential setting circuit composed of pull-up resistors 43 and 44 and capacitors 45 and 46, respectively;
The input terminals are individually connected to the input terminals of an input E/OR (exclusive OR) circuit 47. The output terminal of the E/OR circuit 47 is connected to the input terminal D of the flip-flop circuit 48, and when the detection timing signal 49 is applied to the clock input terminal CK, the detection signal 50 is outputted from the output terminal Q.

The gripping error detection device having such a configuration detects a gripping error immediately after the sheet conveyance device performs a sheet gripping operation. In other words, at this point, solenoid 2
1 is operated, and when the contacts 11 and 12 are lowered, a detection timing signal 49 is generated, and the signal output from the E/OR circuit 47 is taken into the flip-flop circuit 48 and stored.

First, a case will be described in which the paper gripping section grips the paper well as shown in FIG. 2. In this case, the contact terminal 17 of the detection unit located on the right side in the figure is electrically connected to the contact terminal 16 via the contacts 11, 12 and the grippuff finger 3, and is grounded. As a result, the charge is discharged from the capacitor 46, and the potential at the connection point 51 connecting the capacitor 46 and the contact terminal 17 becomes L (low) level. At this time, the contact terminal 17 of the detection section located on the left side in FIG. 2 is insulated from the other contact terminals 16 by the paper 1. Therefore, capacitor 45 and contact terminal 17
The potential at the connection point 52 to which the two are connected is kept at H (high) level by the pull-up resistor 43. In this state, an H-level detection signal 50 is output from the output terminal Q of the flip-flop circuit 48, indicating that the paper is being gripped satisfactorily.

Next, as shown in FIG. 3A, a case will be described in which the paper 1 is not held by the paper gripping section but is covered above it. In this case, the contact terminals 17 of both detection sections are insulated from the other contact terminals 16 by the paper 1. In this state, the potential at both connection points 51 and 52 is H.
level, and the E/OR circuit 47 outputs an L level signal. Therefore, the flip-flop circuit 50 is not set by the detection timing signal 49, and an L level detection signal 50 is output from its output terminal Q, indicating that a paper gripping error has occurred.

Finally, as shown in FIG. 3B, a case will be described in which the sheet 1 is slightly gripped by the sheet gripping section or the sheet 1 falls off without being gripped by the sheet gripping section. In this case, the contacts 11, 12 of both detection parts are in contact with the gripper finger 3 or the gripper bed 4, and the contact terminal 17 is grounded. At this time, the potentials of both connection points 51 and 52 become L level,
An L level signal is output from the E/OR circuit 47. Therefore, the output terminal Q of the flip-flop circuit 50 outputs an L level detection signal 50 indicating that a paper gripping error has occurred in this case as well.

As described above, according to the present invention, it is possible to quickly detect a gripping error in the paper gripping section with a simple mechanism.

Although two sets of detection units are used in the embodiment, it goes without saying that three or more sets may be used to detect the paper gripping situation in more detail. In addition, in the example 1
Although a detection section including a pair of contacts and a contact terminal is used, it is of course possible to share one contact and one contact terminal for each of a plurality of detection sections. Further, it is needless to say that the detection section does not need to be formed separately and may be formed integrally.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a paper gripping section of a paper transport device, Fig. 2 is a plan view showing a state in which paper is normally gripped by the paper transport device, and Figs. 3A and B are views of the paper transport device. A plan view showing a state in which a grasping error has occurred, and FIGS. 4 to 6 show an embodiment of the present invention, of which FIG. 4 is a partially sectional view showing a detection section of a grasping error detection device. , FIG. 5 is a schematic diagram of the pressure contact section to which the detection section is attached, and FIG. 6 is a circuit diagram of the detection circuit section of the gripping error detection device. 1...Paper, 3...Gritzpuffing finger (upper claw), 4a...Step part (lower claw), 10...Detection section, 1
1, 12... Contact, 16, 17... Contact terminal,
21...Solenoid, 31-34...point, 47...
...E/OR circuit, 48...flip-flop circuit.

Claims (1)

[Claims] 1. One elongated conductive lower claw arranged in a direction substantially perpendicular to the direction in which the paper is to be conveyed, and a conductive claw that engages with this lower claw and grips the leading edge of the paper at a predetermined interval. In a paper conveyance system that is equipped with a plurality of upper claws, and these claws grip the paper and move it in a predetermined direction, at any time when the paper should be gripped, these claws are inserted from above the upper claw and the lower claw. a detection unit that detects the presence or absence of paper by contacting an electrode with a predetermined part of the upper claw; What is claimed is: 1. A gripping error detection device comprising: a detection circuit unit that detects a paper gripping error when it is detected that the paper is not present.