JPS62164077A - Fixing roller pressurizing mechanism - Google Patents

Abstract

PURPOSE:To easily release pressure between a pair of fixing rollers or to pressurize it and to easily remove a recording material resident between the rollers by rocking an elastic member at a position releasing the pressurization of the fixing rollers through the rocking center of a lever when an operational lever is rocked in the direction separating from a butted part. CONSTITUTION:With a shaft 41 as a center, the operational lever 4 is slidably loaded on one supporting member, that is, a side plate 103. The elastic member 5 is fitted on one end of a shaft 42 disposed on the intermediate part of the operational lever 4, while on the other end the elastic member 5 is fitted on the fitting part 32 of the supporting member 3. Thus the lever 4 and the supporting member 3 are connected, whereby the lever 4 can pressurize an upper fixing roller 1 and a lower fixing roller 2. When the lever 4 is rocked in the direction of an arrow A with the shaft 41 as a center, pressure arising between said rollers 1 and 2 can be released.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention is used in electrophotography or toll recorders, etc., in which recording materials, such as recording paper, that support an unfixed image, such as an unfixed toner image, on the surface are pressed together. This device relates to a constant-graduation device that fixes the image on a recording material and obtains an image output by passing the image between a pair of fixing rollers. a pair of supporting members connected to the fixing roller, each pivotally supporting the fixing roller, and an elastic member that attracts the vicinity of the other end of the supporting member to each other so as to press the fixing rollers together. The present invention relates to a fixing roller pressure mechanism in a fixing device.

[Background of the invention]

2. Description of the Related Art A device that transfers a toner image onto a recording material and obtains it as an image output, such as a printer using an electrophotographic method, requires means for fixing the toner image onto the recording material. One of the methods is to apply pressure to two fixing rollers facing each other, or to heat the rollers by providing a heater inside at least one of the fixing rollers, so that the unfixed toner image is transferred. A widely used method is to pass a material between the pair of rollers to obtain a finished image output.

In this method, it is necessary to apply a certain amount of pressure between the pair of rollers in order to enhance the heating effect on the recording material, even if the rollers are heated, even if the rollers are not heated.

Conventionally, methods such as those shown in FIGS. 3 and 4 have been used as this pressurizing method. In FIG. 3, the lower measuring roller 1 is pivotally supported by a side plate 103, and the lower measuring roller 22 is connected near one end to a support member 3 that is swingably connected to the side plate about a pivot 31. It is pivoted. An elastic member 5 is provided near the other end of the support member 3 to pull the other end of the support member 3 upward so as to press the fixing rollers 1 and 2 against each other. The end of the elastic member 5 is an adjustment member 101
The adjusting member 101 is fixed to the side plate 103 by, for example, a nut 102, so that the length of the elastic member 5 can be changed. In this configuration, for example, if the recording material jams between a pair of rollers for some reason, the pair of fixing rollers 1 and 2
Since the pressure between the recording materials cannot be easily released, a great deal of effort is required to remove the recording material.

In the configuration shown in FIG. 4, the lower measuring roller 21 is pivotally supported by the upper side plate 103, the lower measuring roller 2 is pivotally supported by the lower side plate 104 via the support member 3, and the lower measuring roller 2 is pivotally supported by the lower side plate 104 via the support member 3.
3 and the lower side plate 104 are swingably connected to each other by a pivot 31 near one end, and a connecting member 105 near the other end.
are connected by.

Further, in order to press the fixing rows 21 and 2 together, a lower side plate 104 and a support member 3 supported at one end by the lower side plate are provided.
An elastic member 5 is disposed between the other end and the other end. In this configuration, a connecting member 105 connects the upper side plate 103 and the lower side plate 10.
In this case, the lower measuring roller 1 and the lower measuring roller 22 are pressurized by fixing the roller 4. If the connecting member 105 is configured to be easily removed, the upper side plate 103 can be opened in the direction of arrow A by removing it, and releasing the pressure is relatively easy. However, since the upper half of the fixing device is opened, It is necessary to pull out the fixing device itself to the outside of the main unit in which it is attached, making the operation difficult.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing roller pressing mechanism that eliminates the above-mentioned drawbacks of the conventional fixing roller pressing mechanism of a fixing device and facilitates jam removal in the fixing device.

[Summary of the invention]

The fixing roller pressing mechanism according to the present invention includes a pair of fixing rollers, a pair of support members that are pivotally connected to each other near one end and that respectively support the fixing rollers, and a pair of supporting members that respectively support the fixing rollers. In a fixing roller pressing mechanism in a fixing device, which includes an elastic member that attracts the other ends of the support members to each other so as to bring them into pressure contact with each other, an actuation lever is swingably attached to one of the support members; one end of the elastic member is attached to the intermediate portion of the actuating lever and the other end is attached to the other support member, and the actuating lever is held in a state in which the elastic member is stretched and pressurizes the fixing roller. An abutting portion against which the actuating lever abuts is formed on one of the support members, and when the actuating lever is swung in a direction away from the abutting portion, the elastic member passes through the center of swing of the lever and is attached to the fixing roller. It is characterized by being pivoted to a position where the pressure is released.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is the lower measuring roller, 2 is the lower measuring roller, and the lower measuring roller 1 is the lower measuring roller.
is pivotally supported by a side plate 103, and the lower measuring roller 2 is pivotally supported by a support member 3, and both support members are connected near one end so as to be swingable about a pivot 31. An elastic member 5 is provided that attracts the pair of support members, that is, the side plate 103 and the vicinity of the other end of the support member 3 to each other so as to press the fixing rollers 1 and 2 together.

In the present invention, one support member, that is, the side plate 103
The actuating lever 4 is mounted so as to be swingable about a shaft 41. The elastic member 5 is attached at one end to a shaft 42 disposed in the middle of the operating lever 4, and at the other end to a mounting portion 32 of the support member 3. As a result, the support member 3 and the lever 4 are connected, and the lever 4 can press the upper fixing roller 1 and the lower fixing roller 2 against each other. 6 is lever 4 when pressurized.
Similarly, reference numeral 7 is the abutting portion in the released state. In the state shown in FIG. 1, pressure is generated between the upper roller 1 and the lower roller 2, but by swinging the lever 4 about the shaft 41 in the direction of the arrow in the figure, the It can be removed by releasing the pressure.

Figure 2 is a schematic diagram showing the state of this pressurizing mechanism.
) is the pressurized state, (b) is the maximum pressurized state, (C) is the steady pressurized state, and the state (C) is the state shown in FIG. FIG. 2(a) shows the state when the lever 4 abuts against 17 as shown by the two-dot chain line 4' in FIG. 1, and the length of the elastic member 5 is slightly longer than its natural length. It is satl. In this state, an extremely weak tensile force is acting between the mounting portion 32 of the support member 3 and the shaft 42, but since the position of the support member 3 is lower than its normal position, the pressure between the rollers is has been canceled.

From this state, move the shaft 42 around the shaft 41 as shown in FIG.
), the elastic member 5 is stretched and a tensile force is generated between the mounting portion 32 and the shaft 42, and as a result, the upper measuring roller 1 and the lower fixing roller 1 are Pressure is created between the rollers 2. The shaft 42 is connected to the mounting portion 32 and the shaft 41.
When the elastic member 5 comes on the extension line of the center line CL connecting the
has a maximum length t2. (Fig. 2 (b)) During the state from (a) to (b), a counterclockwise moment is applied to the shaft 42 with the axis 41 as the center, but in the state (b), the moment is It is. When the elastic member 5 passes through the swing center 41 of the arm, the state shown in (b) changes to the state shown in (C), and the shaft 42 receives a clockwise moment due to the tensile force of the elastic member 5. By restricting this moment with the abutting portion 6, it is possible to
Appropriate pressure is maintained between the rollers.

At this time, the length of the elastic member 5 is longer than the natural length t, and t3 is shorter than the maximum length t2.

With this configuration, from the state (a) where the pressure between the rollers is released to the state (b) where the elastic member 5 reaches the maximum length t2, the elastic member 5 moves against the tensile force of the elastic member 5. However, when the axis 42 crosses the center line CL, the tensile force of the elastic member 5 itself causes 1) Ii4f142
The lever 4 attached thereto abuts against the abutting portion 6 and is stabilized in this state. Conversely, in order to release the pressure between the rollers, it is necessary to apply force from state (c) to state (b), but once state (b) is exceeded, the pressure is released only by the tensile force of the elastic member 5. will be canceled. Furthermore, even when the lever 4 is in contact with the abutting portion 7, a very weak tensile force is acting on the elastic member 5, so this state is stably maintained.

Further, if the position of the abutting portion 6 is made variable, the length t3 of the elastic member 5 is affected, so that the pressure can be adjusted.

〔Effect of the invention〕

As described above, when the pressure mechanism according to the present invention is used, the pressure between the pair of fixing rollers can be easily released or applied, and the recording material staying between the rollers can be easily removed.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view illustrating the pressurizing mechanism according to the present invention, FIGS. 2(b) and (c) are schematic views showing the operating state of the pressurizing mechanism shown in FIG. 4 are longitudinal sectional views showing a conventional pressure mechanism. 1. Upper fixing roller, 2: Lower fixing roller, 3: Support member, 4: Operating lever, 5: Elastic member. figure

Claims (1)

[Claims] a pair of fixing rollers, a pair of support members that are swingably connected to each other near one end and each pivotally supports the fixing roller; and a support member that is configured to press the fixing rollers against each other. In a fixing roller pressurizing mechanism in a fixing device that includes an elastic member that attracts the vicinity of the other ends to each other, an operating lever is swingably attached to one support member, and one end of the elastic member is attached to the operating lever. The elastic member is attached to the middle part and the other end is attached to the other support member, and the abutting part against which the actuating lever is abutted is attached to one side so as to hold the actuating lever in a state where the elastic member is stretched and pressurizes the fixing roller. The elastic member is formed on a support member so that when the operating lever is swung in a direction away from the abutting portion, the elastic member passes through the swiveling center of the lever and oscillates to a position where the pressure on the fixing roller is released. A fixing roller pressure mechanism characterized by: