JPS646518Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roller type fixing device used in a copying machine, particularly an electrophotographic copying machine.

The roller type fixing device includes a pair of roller elements and a pressing force applying means such as a spring that presses the pair of roller elements against each other with a predetermined pressing force.

The roller elements and pressing force applying means in the above-mentioned roller type fixing device are generally supported by a unit case, and the normal operating position and operation of each unit case are made to facilitate removal of jammed paper in the event of a paper jam. The fixing device is configured to be able to move between a non-operating position and a non-operating position, and the fixing device applies a pressing force by the pressing force applying means so that the jam paper held by the roller element is removed without tearing. includes a pressing force release means for selectively releasing the action of the roller elements on the pair of roller elements.

In the case of a copying machine having a roller type fixing device as described above, the jam paper can be easily removed, but the copying operation is carried out while the pressing force of the roller element is released by the pressing force releasing means. If the copying operation is restarted with the pressing force of the roller elements released, problems such as poor fixing and poor conveyance of copy paper may occur.

The present invention has a simple structure so that even if the pressing force of the roller element is released by the pressing force release means, the pressing force releasing state is automatically released when the unit case moves to its normal operating position. It is an object of the present invention to provide a roller type fixing device that is improved so that a predetermined pressing force is applied to the roller element.

The roller type fixing device according to the present invention is characterized in that the pressing force release means has a manual operating lever, and when the manual operating lever is moved from the first position to the second position, the pressing force is When the unit case moves from the non-operating position to the operating position, the unit case collides with an abutting member fixed to the main body of the copying machine, thereby causing the manual operating lever to move to the second position. The present invention further includes a lever return member that is driven from the second position to the first position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the main parts of an embodiment of a roller type fixing device according to the present invention, and FIG. 2 is a view taken in the direction of arrow A. In these figures,
Reference numeral 1 indicates a unit case. A unit case 1 rotatably supports two roller elements 2 and 3. Further, the unit case 1 pivotally supports one end of a pressure lever 5 via a pivot shaft 4. The pressure lever 5 is connected to a spring 6 at its other end, and is biased clockwise in the figure by the spring force of this spring, and engages with the roller element 3 to apply a predetermined pressing force against the roller element 2. It is pressed with

Further, the unit case 1 pivotally supports a bell crank 8 by a pivot 7, and one end of a pressing force release link 10 is pivotally connected to one end of the bell crank by a pin 9. The pressing force release link 10 engages near the other end of the pressure lever 5 at a fork portion 11 formed at the other end. A cam follower roller 13 is pivotally supported at the other end of the bell crank 8 by a pin 12. A cam follower roller 13 engages an eccentric cam 15 carried on a camshaft 14. The camshaft 14 is fixedly supported by the unit case 1, and a manual operation lever 16 is attached to one end thereof. The manual operating lever 16 is movable between a first position, as shown in solid lines in FIG. 2, and a second position, as shown in phantom lines. When the eccentric cam 15 is rotated to the second position, the eccentric cam 15 is rotated counterclockwise in the figure, and the bell crank 8 is accordingly rotated counterclockwise in the figure to release the pressing force release link. 10 and rotate the pressure lever 5 against the spring force of the spring 6 from the rotation position shown by the solid line in FIG. 2 to the rotation position shown by the imaginary line in the figure. The spring force of the spring 6 is released from acting on the roller element 3. The camshaft 14 is urged clockwise by a torsion coil spring 17, that is, the manual operating lever 16 is urged from the second position to the first position. Note that when the manual operation lever 16 is in the second position, the engagement between the cam follower roller 13 and the eccentric cam 15 causes the manual operation lever 16 to remain stable in the second position against the action of the torsion coil spring 17. It has become stationary.

The unit case 1 is movable in the left and right directions as shown in the figure, and is normally located at the normal operating position as shown in the figure.When removing jammed paper in the event of a paper jam, etc., the unit case 1 is moved from its normal operating position as shown in the figure. It is adapted to be brought into an inoperative position displaced to the right.

A return lever 18 is attached to the other end of the camshaft 14. The return lever 18 is the manual operation lever 1
When the unit case 1 is moved from the non-operating position to the regular operating position when the unit case 6 is in the second position, it collides with an abutting pin 19 attached to the main body of the copying machine (not shown). camshaft 1
4 is forcibly driven clockwise in the figure.

To remove jammed paper when a paper jam occurs, move the unit case 1 from its normal operating position to the right in the figure, and rotate the manual operating lever 16 from its first position to its second position. Release the pressing force of the roller element. After the jam paper has been removed in the above-described condition, when the unit case 1 is moved from its non-operating position to the left in the figure, that is, toward its normal operating position, the return lever 18 is moved from its non-operating position. As it moves, it collides with the abutting pin 19, and as a result, the camshaft 14 is forcibly rotated clockwise in the figure. This rotation causes the manual operation lever 16 to
is returned from the second position to the first position, and as the cam 15 rotates accordingly, the pressure lever 5 is moved again to the roller element 3 by the spring force of the spring 6.
is now pressed toward the roller element 2.

As is clear from the above explanation, according to the present invention, even if the manual operation lever is forgotten to be returned, when the unit case 1 is returned to its normal position, the manual operation lever is automatically activated as the unit case 1 is returned to its normal position. returned to the first position, the pair of roller elements are pressed against each other with a predetermined pressing force,
This prevents problems such as fixing failure and copy paper conveyance failure due to forgetting to release and return the fixing pressure.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main parts of an embodiment of a roller type fixing device according to the present invention, and FIG. 2 is a view taken in the direction of arrow A. 1... Unit case, 2, 3... Roller element, 4
... Pivot, 5... Pressure lever, 6... Spring, 7... Pivot,
8... Bell crank, 9... Pin, 10... Pressure release link, 11... Fork part, 12... Pin, 13...
Cam follower roller, 14... cam shaft, 15... eccentric cam, 16... manual operation lever, 17... torsion spring,
18...Return lever, 19...Abutting pin.

Claims (1)

[Scope of utility model registration request] a pair of roller elements, a pressing force applying means for pressing the pair of roller elements against each other with a predetermined pressing force, and selectively applying a pressing force to the pair of roller elements by the pressing force applying means. and a pressing force release means for releasing the copying force, these are attached to one unit case, and the unit case is movable with respect to the copying machine body between a normal operating position and a non-operating position displaced from the operating position. In the roller type fixing device, the pressing force releasing means includes a manual operation lever, and when the manual operation lever is moved from the first position to the second position, the pressing force acts on the roller element. When the unit case moves from the non-operating position to the operating position, the manual operating lever is moved from the second position to the second position by colliding with an abutment member fixed to the main body of the copying machine. A roller type fixing device characterized by having a lever return member that moves the lever to the first position.