JPH0322764Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a pressure release mechanism between a fixing roller and a pressure roller in a fixing device of a copying machine or the like.

PRIOR ART Conventionally, when a paper jam or the like occurs near the fuser, the user opens the rear cover, moves a pressure release lever, and opens the fuser cover to correct the problem. Also, because of this, I sometimes forgot to fix the pressure release lever.

Purpose The present invention makes it possible to easily clear paper jams in the fixing device that performs heat-pressure fixing in image printing devices (copiers, printers, etc.), and also simplifies its configuration. An object of the present invention is to provide a pressure release mechanism that can easily release the pressure between a heating roller and a pressure roller.

Configuration The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 is a side sectional view showing the vicinity of a fixing device of a copying machine, etc., in which a transfer paper P, onto which a toner image has been transferred from a photoreceptor belt A, is fixed with heat and pressure in a fixing device B, and is then fixed on a paper discharge tray C. It is now being discharged. That is, an optical writing section, a developing section, a transfer charger, etc. (not shown) are provided around the photoconductor belt A, and the toner image is transferred at the lower left end of the photoconductor belt A in FIG. The paper P is guided by the entrance guides 1, 1', 1'' as shown by the arrow,
A fixing roller 3 is rotatably supported on a side plate 2 of the fixing device B, and a pressurizing arm 6 whose one end is supported 4 on the side plate 2 and whose other end is pressed against the fixing roller by a pressurizing spring 5 is rotatably attached to a pressurizing arm 6. After being guided between the supported pressure roller 7 and thermally fixed, it is guided to the separation claw 8 and the fixing exit guide 9, and then ejected by the paper ejection roller 10, paper ejection guide 11, and paper ejection roller 10'. The paper is ejected to paper tray C.

To explain in more detail, the fixing side plate 2 has one end rotatably supported by a shaft 12, and the other end is biased by a spring 14 to rotate clockwise by a pin 13. lock lever 1
5, and its tip 16 is attached to the fuselage side fixing pin 1.
It is configured to be fixed to the fuselage by engaging with 7. The pressure roller 7 is brought into pressure contact with the fixing roller 3 which is pivotally supported on the fixing side plate 2 by a pressure spring 5 provided between the machine body and the pressure arm 6, so that the pressure arm 6 is rotated counterclockwise around the shaft 4. By applying pressure in this direction, the pressure roller 7 supported by the pressure arm 6 is brought into pressure contact with the fixing roller 3.

In the present invention, since the fixing device B is configured as described above, in the normal state, the tip 16 of the lock lever 15 rotatably attached to the fixing side plate 2 is attached to the fuselage as shown in the first figure. The pressurizing arm 6 engages with a fixing pin 13 provided in the fixing pin 13 and is pressurized by a pressurizing spring 5 on the machine body side.The pressurizing arm 6 presses a pressurizing roller 7 pivotally supported by the pressurizing arm 6 against the fixing roller 2 to perform a fixing action. let

By the way, if a paper jam or the like occurs around the fuser B, if the rear cover 18 is tilted back around the support shaft 19 and the lock lever 15 is rotated against the spring 14 to the position shown by the dotted line in FIG. The state will be as shown in Figure 2. That is, the lock lever 15 is
7, the fixing side plate 2 can freely rotate around the support shaft 12, and the pressure arm 6 is no longer affected by the pressure spring 5, so that the pressure arm 6 and the pressure roller 7 are separated from each other. The pressure arm 6 rotates downward under its own weight, and the fixing roller 3 and pressure roller 7 are separated. In order to create a gap between the fixing roller 3 and the pressure roller 7, the outer surface of the tip 16 of the lock lever 15 and the pin 17 should be
This may be done by keeping the fixing side plate 2 supported by engagement with the fixing plate 2, or by slightly biasing the fixing side plate 2 counterclockwise around the shaft 12 with a spring. good. A stopper (not shown) is provided to prevent the pressure arm 6 from rotating beyond a certain level when the fixing side plate 2 rotates counterclockwise.

In such a state, the jammed transfer paper can be easily removed from the fixing device B.

In addition, by pushing down the upper part of the fixing side plate 2 in the state shown in the second figure, the lock lever 15 engages with the pin 17, and the state returns to the state shown in the first figure, fixing the fixing side plate 2 to the machine body, and at the same time pressurizes the fixing roller 3. The roller 7 is brought into pressure contact with the roller 7.

FIG. 3 shows the engagement relationship between the pressure arm 6 and the pressure spring 5, where a is a perspective view and b is a front view. The pressure spring 5 is housed in a cylinder 20 fixed to the fuselage. The end of the pressing arm 6 is guided along a guide groove 21 provided in the cylinder 20 and receives the action of the pressing spring 5. Also, unlike FIG. 3, FIG. 4 shows an embodiment in which a pressure spring 5 is fixed to a pressure arm 6, and the pressure arm 6 is pressurized by pressure contact between the pressure spring 5 and the body. Here, a is a side view and b is a front view.

Furthermore, FIG. 5 is a side view showing an embodiment in which the pressing force of the pressure roller 7 can be adjusted.
The part of the pressurizing arm 6 that pivotally supports the pressurizing spring is made separately as the pressurizing adjusting arm 22, and the pressurizing adjusting arm 22 is fixed relative to the pressurizing arm 6 using the fixed pin 23 and the eccentric pin 24. , the mounting angle can be adjusted so that the pressing force by the pressing spring 5 can be adjusted.

Effects As explained above, according to the present invention, by rotating the fixing device B, that is, by rotating the fixing side plate 2, the pressure contact between the heating fixing roller 3 and the pressure roller 7 is also released at the same time. Conversely, if you push down the fixing side plate 2, the fixing roller 3 and pressure roller 7 will come into pressure contact at the same time as the fixing device B returns to its normal position, so the pressure contact between the fixing roller and the pressure roller will be reduced. Not only can the release be easily performed, but there is no risk of forgetting to adjust the pressure release lever unlike in the conventional case.

[Brief explanation of the drawing]

Figure 1 is a side sectional view showing the vicinity of the fixing device, Figure 2 is a side sectional view similar to Figure 1 showing a state where the rear cover is opened and the pressure contact between the fixing roller and the pressure roller is released, and Figure 3 a. , b and FIGS. 4a and 4b are a side view and a front view showing the relationship between the pressure arm and the pressure spring, respectively, and FIG. 5 is an embodiment in which the pressure contact force between the fixing roller and the pressure roller can be adjusted. FIG. A... Photoreceptor belt, B... Fixing device, C... Output tray, P... Transfer paper, 1... Entrance guide, 2
... Fixing side plate, 3 ... Fixing roller, 4 ... Pressure arm shaft, 5 ... Pressure spring, 6 ... Pressure arm, 7 ... Pressure roller, 10 ... Paper ejection roller, 11 ... Paper ejection guide, 12... Fixing side plate rotating shaft, 13... Pin, 1
4... Spring, 15... Lock lever, 17... Fixed pin, 18... Rear cover, 19... Rotating shaft,
22...Pressure adjustment arm, 24...Eccentric pin.

Claims (1)

[Scope of utility model registration request] One end of the pressure arm that supports the pressure roller facing the fixing roller is rotatably supported on the fuser side plate, which has one end rotatably supported on the machine body, and the other end is rotatably supported on the fuser side plate. A pressure spring is interposed between them, and the fixing device side plate is rotated in a direction that compresses the pressure spring, so that the fixing roller and the pressure roller, which are pivotally supported by the fixing device side plate, are brought into pressure contact with each other. A fixing device characterized in that the fixing roller is maintained by engagement between a lock lever provided on a side plate of the device and a fixing pin provided on the body, and the pressure contact between the fixing roller and the pressure roller is released by disengaging the lock lever from the fixing pin. Pressurization release mechanism of the vessel.