JPH1069185A - Jam processing mechanism of thermal roll fixing device - Google Patents

Abstract

(57) [Summary] A peeling claw (11) attached to a discharge part (2).
Is prevented from protruding into the jam clearance path when the discharge unit (2) is opened. SOLUTION: In conjunction with the opening / closing operation of a discharge unit (2), when a discharge unit (2) is in an open state, a holding unit (4) of a peeling claw (11) has a toe of the peeling claw (11) from a jam processing passage. The peeling claw holding portion (4) is provided with an interlocking mechanism which is turned to a retracted posture and the peeling claw holding portion (4) is rotated to a posture in which the peeling claw comes into contact with the fixing roll (15) when the discharge portion (2) is closed. The interlocking mechanism is a spring that urges the connecting wire (5) connecting the peeling claw holder (4) and the apparatus main body and the peeling claw holder (4) to the predetermined position of the discharge unit (2). (6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a jam processing mechanism of a heat roll fixing device of an image forming apparatus such as an electrophotographic copying machine.

[0002]

2. Description of the Related Art A thermal roll fixing device widely used as a fixing device of an image forming apparatus using an electrophotographic process such as an electrophotographic copying machine generally has a function of separating a fixed transfer paper from a fixing roll. As shown in FIG. 5, the peeling claw 11 is pressed so that the toe 11a is pressed against the fixing roll 15.
Is provided. The transfer paper peeled off from the fixing roll 15 by the peeling claw 11 is discharged out of the apparatus by discharge rollers 18 and 19.

As a mechanism for performing jam clearance in the fixing device, a driven roller 19, a peeling claw 11, and a discharge port 2 including a discharge port among a pair of discharge rollers 18, 19 are provided with a pivot shaft at a lower end portion. A well-known structure in which the upper portion is rotated around a center 23 and fixed to a heater hatch 1 whose upper portion can be opened and closed greatly so as to be able to be opened and closed integrally.

In the conventional example shown in FIG. 5, the peeling claw 11 is urged by a spring 20 in a direction in which it comes into pressure contact with the fixing roll 15 in order to resiliently press its toe against the fixing roll 15. The posture of the peeling claw 11 with respect to the discharge unit 2 does not basically change, and as shown by a solid line in FIG. 5, the discharge unit is pressed against the fixing roll 15 in a predetermined peeling position at a predetermined peeling position. The peeling claw 11 attached to 2 is
At the time of jam clearance, when the heater hatch 1 and the discharge unit 2 are rotated about the pivot shaft 23 at the lower end thereof and the upper part is greatly opened as shown by a dashed line in the figure, the peeling claw 11 is moved to the tip 11a. However, when the paper jams, the user may be injured by the operator's hand or the like during the paper jam processing.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the conventional jam processing mechanism of a heat roll fixing device, and has been described in view of the above problem. An object of the present invention is to provide a jam processing mechanism which is excellent in safety without protruding.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a jam processing mechanism of the present invention provides a jam processing mechanism of a heat roll fixing device having the above-described structure, which operates in conjunction with the opening / closing operation of a discharge unit. In the open state of the discharge unit, the toe of the peeling claw is rotated to a position of retreating from the jam processing passage, and in the closed state of the discharge unit, the toe of the peeling claw is rotated to the peeling position where the toe is pressed against the fixing roll. It is characterized by having.

The interlocking means has one end locked to the discharge portion and the other end locked to a peeling claw holding unit for holding the peeling claw, and holding the peeling claw in a direction of pressing the tip of the peeling claw against the fixing roll. Both ends of the spring for urging the unit, the discharge unit and the device body frame are respectively locked, and when the discharge unit is opened from the closed state, the discharge unit is slack within a predetermined opening degree,
An interlocking wire that rotates the peeling claw holding unit to a posture in which the tip of the peeling claw retracts from the jam processing passage against the urging force of the spring when the discharge unit is in the predetermined opening degree or more. It can be configured to have.

The interlocking means is a link mechanism which, in conjunction with the opening and closing movement of the discharge unit, rotates the peeling claw holding unit in a direction in which the tip of the peeling claw retreats from the jam processing passage as the discharge unit opens. You may comprise.

[0009]

FIG. 1 is a side view showing an example of a jam processing mechanism of a heat roll fixing device to which the present invention is applied, and FIG. 2 is a perspective view showing a part of a peeling claw holding unit. is there. In FIG. 1, in order to show the positional relationship of the necessary constituent members, parts that are not originally visible behind the members are also shown by solid lines. In FIG. 2, only the main parts are shown for simplicity and for easy viewing.

In the jam removing mechanism of this embodiment, the heater hatch 1 is configured such that the discharge portion 2 is integrally rotated about a pivot shaft 23 at a lower end thereof to open an opening for jam clearance and a jam subsequent thereto. The point of forming the processing passage is not different from the conventional example described with reference to FIG. However, the peeling claw 11 is held by a peeling claw holding unit 4 rotatably attached to the discharge unit 2 by the pivot 3.

As shown in FIGS. 1 and 2, the peeling nail holding unit 4 comprises a peeling nail holding plate 4a and side plates 4b fixed to both ends thereof. A plurality of peeling claws 11 are provided at predetermined intervals on an edge of the peeling nail holding plate 4a facing the fixing roll.
Is held. At the other end of the separation claw holding plate 4a, a plurality of discharge rolls 19
Are rotatably mounted.

A pivot 3 is implanted on the side plate 4b of the peeling claw holding unit 4, whereby the peeling claw holding unit 4
Are pivotally supported by the discharge unit 2. Pivot 3
, A coil spring 6 is further wound. One end 9 is locked to the discharge unit 2, and the other end 10 is locked to a notch provided on the side plate 4 b of the peeling claw holding unit 4. Energizing counterclockwise.

A pin 21 is further implanted on the side plate 4b of the peeling claw holding unit 4. One end 7 of the connecting wire 5 is hooked on the pin 21. The other end 8 of the connecting wire 5 is attached to the lower plate of the fixing unit as shown in FIG. The attachment point of the one end 8 of the connecting wire 5 is not limited to the lower plate of the fixing unit, but may be an appropriate location of the apparatus body frame or a member fixed thereto. The connecting wire has a locking ring formed by crimp terminals at both ends of a stainless steel wire rope. The connecting wire acts as a tension member, and becomes slack when no tension is applied. Conventional gears, levers, cams, cranks, etc. Can be used instead of
It is focused on from the viewpoint of achieving small size, light weight and low cost. Note that a similar effect can be obtained even if a chain is used instead of the above-described wire rope.

The length of the connecting wire 5 is
When the heater hatch 1 is opened in a normal state in which the connecting wire 5 is slackened, and when the heater hatch 1 is opened, the connecting wire 5 is set to be in a tensioned state when a certain opening degree is reached.

The operation of this device will be described below. In the normal state where the heater hatch 1 is closed, the connecting wire 5
Is in the sagging state as described above, the peeling claw holding unit 4 is pushed up by the counterclockwise urging force of the spring 6 until it comes into contact with the stopper portion 12 of the discharge portion 2.
At this position, the cutting edge 11a of the peeling claw 11
At a regular peeling position.

Jam occurs in the fixing section, and the jam paper is removed.
Inspection and the like are required, and when the heater hatch 1 is rotated counterclockwise around the pivot shaft 23 at the lower end thereof and opened, the discharge portion 2 is also opened integrally. At that time, heater hatch 1
Until the opening of the connecting wire 5 reaches a certain angle, the connecting wire 5 is in a slack state, so that the peeling claw holding unit 4 is kept pressed by the stopper 12 of the discharge unit 2 by the biasing force of the spring 6. When the opening of the heater hatch 1 reaches a certain angle, the connecting wire 5 is in a tensioned state. When the connecting wire 5 is further opened, the peeling claw holding unit 4 is pulled by the wire 5 against the urging force of the spring 6, It rotates clockwise around the pivot 3 in the figure. As a result, in FIG. 1, the blade edge 11a of the peeling claw 11 faces a substantially horizontal direction and comes to a position where it does not protrude toward the jam clearance path.

In the above-described embodiment, the spring 6 and the connecting wire 5 are used in combination as the interlocking means for opening and closing the discharge unit 2 and changing the posture of the peeling claw 11.
In other words, by using a link mechanism that rotates the peeling claw holding unit about the pivot 3 in the opposite direction at substantially the same angle in conjunction with the rotation angle about the pivot shaft 23,
The peeling claw holding unit 4 can always be maintained in a substantially horizontal posture.

FIGS. 3 and 4 show examples of link mechanisms for achieving this, respectively. In the link mechanism of FIG.
1 is resiliently held by the peeling claw holding unit 4, and the peeling claw holding unit 4 is pivotally supported by the discharge unit 2 by a pivot 3. The discharge unit 2 is pivotally connected at its lower end to a pivot shaft 23 implanted in the apparatus body frame. A pin 21 is implanted on a side plate (see FIG. 2) of the peeling claw holding unit 4. In a normal state where the toe of the peeling claw 11 is pressed against the fixing roll 15 at a predetermined peeling position, the direction and the distance from the pivot shaft 23 become the same as the line (3.21). , A pin 24 is implanted, and the pin 21 and the pin 24 are connected by a rod 25. Then, 4 points 3, 2
3, shown by the broken line in FIG.
The parallelogram is a parallelogram, and a parallelogram link is formed by the rod 25, the peeling claw holding unit side plate 4, the discharge unit 2, and the machine frame. Therefore, when the discharge unit 2 is opened and closed by rotating it around the pivot shaft 23 at the lower end, the line segment (3.21) always keeps parallel to the line segment (23.24), and the peeling claw is held. The unit 4 always keeps the posture where the peeling claw 11 is substantially horizontal.

In another example of the link mechanism shown in FIG. 4, a pivot is mounted on a peeling claw holding unit 4 for holding the peeling claw 11 resiliently, and pivotally supports this unit to the discharge unit 2 in a swingable manner. 3 and pulleys 26 and 27 having substantially the same diameter are fixed to the pivot shafts 23, which are implanted in the apparatus main body frame and pivotally connect the discharge portion 2 at the lower ends thereof, so that the pulleys 26 and 27 cannot rotate with respect to the shafts. I have. 2
An endless belt 28 is stretched over the two pulleys 26 and 27. Therefore, when the discharge unit 2 is rotated about the pivot shaft 23, the pulley 26 rotates by substantially the same angle as the rotation angle of the pulley 27 with respect to the discharge unit 2, and the peeling claw holding unit 4 always operates the peeling claw 11. Holds a posture that is substantially horizontal.

[0020]

As described above, according to the present invention, in the normal state in which the discharge unit is closed, the peeling claw holds the accurate peeling position, and when the discharge unit is opened for jam processing or the like, the peeling claw is not removed. Since the toe of the nail is retracted from the jam processing passage, there is no risk of injury due to the hand or the like being caught on the toe of the peeling nail during jam processing or the like, and the effect of improving safety is obtained.

Since the interlocking mechanism for interlocking the opening and closing of the discharge unit and the rotation of the peeling claw holding unit is constituted by the spring and the connecting wire, the structure is simplified, and the effect of reducing the weight and improving the reliability is obtained. . If the interlocking mechanism can be constituted by a simple link mechanism, the effect of cost reduction can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view of an embodiment of a jam processing mechanism to which the present invention is applied.

FIG. 2 is a simplified perspective view showing a part of a peeling claw holding unit of the embodiment.

FIG. 3 is a side view showing one embodiment in which a link mechanism is used as an interlocking means for opening and closing a discharge unit and a peeling claw holding unit.

FIG. 4 is a side view showing another embodiment using a link mechanism as an interlocking means.

FIG. 5 is a side view showing an example of a jam processing mechanism of a conventional heat roll fixing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater hatch 2 Discharge part 3 Pivot 4 Peeling claw holding unit 4a Peeling claw holding plate 4b Side plate 5 Connecting wire 6 Spring 11 Peeling claw 12 Stopper part 15 Fixing roll 23 Pivot shaft 25 Rod 26, 27 Pulley 28 Endless belt

Claims (3)

[Claims] 1. A peeling claw, which normally occupies a peeling position where a toe is pressed against a fixing roll, is attached to a discharge portion which is opened and closed for jam clearance and the like, and is released in conjunction with an opening operation of the discharge portion. Is retracted from the fixing roll and a jam processing path is formed in the jam processing mechanism of the heat roll fixing device. In the open state of the discharge section, the toe of the peeling claw is jammed when the discharge section is opened and closed. A jam processing mechanism comprising: an interlocking unit that is rotated to a position to withdraw from the passage, and is rotated to a peeling position where the tip of the peeling claw is pressed against the fixing roll when the discharge unit is closed. . 2. The peeling claw is held by a peeling claw holding unit rotatably provided on the discharge unit, and the interlocking means has one end locked to the discharge unit and the other end connected. A spring that is locked to the peeling claw holding unit and biases the peeling claw holding unit in a direction to press the toe of the peeling claw against the fixing roll, and both ends of the spring are locked to the discharge unit and the apparatus body machine frame, respectively. When the discharge section is opened from the closed state, the discharge section becomes slack within a predetermined opening degree, and becomes in a tensioned state at a predetermined opening degree or more of the discharge section, and peels against the urging force of the spring. The jam processing apparatus according to claim 1, further comprising a connecting wire that rotates the peeling claw holding unit so that a tip of the claw is retracted from the jam processing path. 3. The peeling claw holding unit that holds the peeling claw in a direction in which the toe of the peeling claw withdraws from the jam processing passage as the discharge part opens, in conjunction with the opening and closing movement of the discharge part. The jam processing mechanism according to claim 1, further comprising a link mechanism for rotating the jam.