JPS638915Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a paper peeling device for a pressure fixing device in an electronic copying machine, a facsimile machine, a printer, etc.

In electronic copying machines, hard copies are obtained by fixing toner images formed on recording paper, and one of the fixing methods is to place the recording paper between a pair of fixing rolls that rotate while pressing against each other. A so-called pressure fixing method in which paper is passed is known. Generally, in this pressure fixing, the surface of the fixing roll is polished to a mirror finish in order to prevent toner from adhering to the surface of the fixing roll. However, when a recording paper is passed between a pair of fixing rolls having mirror-finished surfaces as described above, a phenomenon occurs in which the recording paper adheres to the surface of the roll and is not ejected. For this reason, a typical pressure fixing device is provided with means for peeling off the recording paper adhered to the surface of the fixing roll so that the recording paper can be smoothly discharged from the fixing roll.

FIG. 1 is a perspective view of a fixing roll provided with a conventional paper peeling means. Conventionally, as shown in FIG. 1, the tip of a peeling plate 1 made of a non-magnetic material (the peeling plate for the fixing roll 2' is omitted in the figure) is pressed against the surface of the fixing rolls 2, 2'. It was. In this case, the tip of the peeling plate 1 is formed into a wedge shape to facilitate the peeling of the recording paper from the roll surface, and from the viewpoint of strength, a rigid body such as phosphor bronze or stainless steel is used for the peeling plate. ing. However, with such a release plate, when the release plate is removed from the pressure fixing device when toner adheres to the tip of the release plate or the recording paper wraps around the roll surface without being peeled off, the wedge-shaped release plate is removed. Care must be taken when handling to avoid injury to the human body due to the tip. In addition, the tip of the peeling plate must be brought into contact with the surface of the fixing roll without any gaps over a width corresponding to the width of the recording paper, and the peeling plate 1 must be pressed with the pressure necessary to peel the recording paper from the surface of the fixing roll. It is necessary to always press the tip of the fuser roll against the surface of the fuser roll. For this reason, it is necessary to tighten the processing precision of the tip of the release plate, but since the width of the peel is usually about 300 to 400 mm, it is extremely difficult to finish the tip of the release plate with high precision over such a wide range. Have difficulty. Furthermore, in order to keep the pressing pressure of the release plate constant, it is required that the mounting accuracy of the release plate be made strict.

The purpose of the present invention is to solve the above-mentioned problems of the conventional technology, to be able to reliably peel the recording paper from the roll surface regardless of the processing accuracy and installation accuracy of the peeling plate, and to make installation and removal easy and safe. It is an object of the present invention to provide a paper peeling device for a pressure fixing device that can be easily removed.

The details of the present invention will be explained below with reference to the drawings.

FIG. 2 is a sectional view of a main part of a pressure fixing device equipped with a paper peeling device of the present invention. Fixing roll 2, 2'
is rotatably supported at both ends by a pair of housings 3 (only one is shown in the figure) via bearings (not shown). Peeling claws 4 and 4' having wedge-shaped tips are rotatably attached to support rods 5a and 5'a, respectively. As shown in FIG. 4 (however, in FIG.
It is assumed that a plurality of peeling claws 4 and 4' are arranged at predetermined intervals in the axial direction of the fixing roll. Also, the support rod 5a
and 5'a are attached to L-shaped guide grooves 6a and 6'a provided on the side surface of the housing 2, respectively. Furthermore, one end of a tension coil spring 7 is attached to each of the distal ends of the peeling claws 4 and 4' on the side that contacts the surface of the fixing roll. The other ends of the tension coil springs 7 are attached to other support rods 5b and 5'b provided below and above the support rods 5a and 5'a, respectively. Therefore, the tips of the peeling claws 4 and 4' are pulled in the direction of the support rods 5b and 5'b by the tension coil springs 7, respectively.

With this configuration, the tips of the peeling claws 4 and 4' are pressed against the surfaces of the fixing rolls 2 and 2', respectively, by the tension coil springs 7. Moreover, since there are gaps, although slight, between the support rods 5a and 5'a and the mounting holes of the peeling claws 4 and 4', the machining accuracy of the tips of the peeling claws 4 and 4' and the housing 2 of each support rod are limited. Even if the mounting accuracy is not so high, the tips of the peeling claws 4 and 4' can be brought into uniform contact with the surfaces of the fixing rolls 2 and 2', respectively, without any gaps. Furthermore, since the guide grooves 6a and 6'a provided on the side surface of the housing 3 start from the edge of the housing 3, the support rod 5a
and 5'a are guide grooves 6a and 6'b, respectively.
can be easily attached and detached. That is, even if toner adheres to the tip of the peeling claw or recording paper wraps around the surface of the fixing rolls 2, 2', the paper peeling device can be easily attached and removed. Note that the peeling claw may be made of metal or plastic as long as it is a non-magnetic material, but if it is made of plastic, it will prevent the human body from being injured by the edge of the peeling claw, resulting in safer installation and Removal work becomes possible.

FIG. 3 is a schematic sectional view of a pressure fixing device showing another embodiment of the present invention. Also in FIG. 3, the peeling claw 4'' has a wedge-shaped tip and is rotatably attached to a support rod 5c, and the support rod 5c has an open end formed on the side surface of the housing 3. However, in FIG. 3, since the separating claw 4'' is made of metal with a large mass, the tip of the separating claw 4'' is supported by its own weight. It rotates downward about the shaft 5c as a fulcrum.Therefore, the tension coil spring 7 and the support rod 5 as shown in FIG.
Even without using b, the peeling claw 4'' can be uniformly pressed against the surface of the fixing roll 2 in the axial direction of the roll.

Specific example In Figure 2, a Delrin peeling claw with a width of 20 mm is used, a polished steel bar with a diameter of 5 mmφ is used as the support rod, and a spring steel wire with a wire diameter of 0.4 mmφ is wound as a tension coil spring to form a coil with an outer diameter of 5 mm. When I installed a peeling claw at both ends and the center of the fixing roll and passed a sheet of B4-sized photosensitive paper between the fixing rolls, the photosensitive paper was peeled off from the surface of the fixing roll without any problem. I confirmed that the

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of the main parts of a pressure fixing device to explain a conventional paper peeling mechanism, FIG. FIG. 4 is a cross-sectional view of a pressure fixing device showing another embodiment. FIG. 4 is a schematic perspective view showing the relationship between the fixing roll and the peeling claw shown in FIG. 2. 1...Peeling plate, 2, 2'...Fixing roll, 3...
...Housing, 4,4''...Peeling claws, 5a, 5b,
5'a, 5'b, 5c...Support rod, 6a, 6b,
6'a, 6'b, 6c...Guide groove, 7...Tension coil spring.

Claims (1)

[Claims for Utility Model Registration] 1. At least two fixing rolls that rotate while being pressed against each other are supported by a pair of housings facing each other at a predetermined interval, and a toner image is held in the direction of the fixing rolls. At least one support rod extending in the axial direction of the fixing roll is provided on the discharge side of the recording sheet of the pressure fixing device through which the recording sheet passes through, and each of the support rods has a plurality of triangular cross sections. A peeling claw is rotatably mounted so that its tip comes into contact with the surface of the fixing roll, and a substantially L-shaped guide groove starting from the discharge side edge is provided on the opposing sides of the pair of housings. . A paper peeling device for a pressure fixing device, wherein both ends of the support rod are inserted deep into the guide groove. 2. A second support rod is provided in a direction farther from the recording sheet than the support rod, and the second support rod is provided with the other ends of a plurality of coil springs, one end of which is fixed near the tip of each of the peeling claws. Registration of a utility model characterized in that a second guide groove is provided on the opposing side surfaces of the housing, and the second support rod is inserted deep into the second guide groove. A paper peeling device for a pressure fixing device according to claim 1. 3. A paper peeling device for a pressure fixing device according to claim 2, wherein the support rod and the second support rod are also provided for the other fixing roll.