JPS63127940A - Guide device - Google Patents

Abstract

PURPOSE:To facilitate handling of a paper jam and internal cleanup, by supporting a device, guiding a sheet to a fixing roller pair which passes the sheet by pressing with each other, with a supporting device being free of rotation, and making it detachable in a spot other than the specified position. CONSTITUTION:A frame 20 supporting a heating roller 1a with a heater 4 inside is rotated in an arrow A direction around a fulcrum 9 if a latch is released. A frame 7 supporting a pressure roller 1b is vertically rocked around a fulcrum 8. In the state shown in illustration, a sheet is drawn in from an inlet guide plate 18, subjected to a fixing process by these paired heating and pressure rollers 1a and 1b, led into a lower guide plate 14, and discharged out of delivery rollers 12 and 13. When the frame 20 is unlatched and rotated in the arrow A direction, the lower guide plate 14 is released from a plate spring 11. The lower guide plate 14 is rotated counterclockwise and made into verticality, then it is separated from a bearing 15 in an arrow B direction. With this constitution, the handling of a paper jam and cleanup of rollers and their replacement are easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for guiding a recording medium when the sheet-like recording medium is sandwiched between the pressure contact portions of a pair of rollers that are in pressure contact and rotate together in cooperation with each other. The present invention relates to a method for supporting means, and more particularly to a method for supporting means for guiding a recording medium passing through a pair of rollers of a heating roller type fixing device.

Conventional technology Various fixing methods using heat have been proposed in the past.
In recent years, from the viewpoint of downsizing and power saving of fixing devices, a heating roller method has been developed, in which the toner powder image is fused to a recording medium such as copy paper by passing it between a pair of rotating rollers that are heated and pressed against each other. A fixing device is mainly used.

Hereinafter, a conventional guide device will be described using the above-mentioned fixing device as an example. FIG. 3 shows a sectional view of the fixing device. 1a is a heat-resistant mold release layer 3 on the outer peripheral surface of a metal hollow core 2;
4 is a heating roller 1a coated with
1b is a pressure roller whose metal core 6 is coated with a heat-resistant elastic layer 6 such as silicone rubber; 7 is a first fulcrum 8;
Pressure roller support means 17 rotatably supports the pressure roller 1b while being rotatably supported by the pressure roller support means 7; 3o is an inlet guide means for guiding a sheet-like recording medium (not shown) carrying a toner powder image to a pressure contact portion of a pair of heat rollers 1a and 1b; 31 and 32 are a pair of heat rollers 1a and 32, respectively; upper guide means and lower guide means for guiding the recording medium after passing through 1b; 33;
are the entrance guide means 3o and the upper guide means 31. This is a pressure roller frame that fixes and supports the lower guide means 32, and fastening means such as screws are used for fixing.

To explain the operation of the fixing device configured as described above, a sheet-shaped recording medium (not shown) conveyed from the right side of FIG. While being guided by the curve, it enters the pressure contact portion of the pair of heat rollers 1a and 1b, which are in pressure contact with each other and are rotating in the direction of the arrow, and is sent to the left. The heating roller 1a is heated from its inner surface by a heating roller 4 and is controlled to keep the surface temperature constant. Follow me,
Toner powder made of a thermofusible resin is deposited on the recording medium that has passed through the heat roller pair 1&, 1b due to the action of heat and pressure. After passing through the pair of heat rollers 1a and 1b, the recording medium is guided between an upper guide means 31 and a lower guide means 32, and is removed from the fixing device by a pair of discharge rollers 12 and 13 that are in pressure contact with each other and rotate together. It is discharged.

Problems to be Solved by the Invention Such conventional guide devices have been widely adopted along with the spread of heating roller type fixing devices. This poses problems such as when a recording medium such as paper gets wrapped around the pressure roller, and when cleaning or replacing the pressure roller, it is necessary to temporarily remove the guide means, which is a complicated operation. are doing.

Means for Solving the Problems The present invention solves the above-mentioned conventional problems, and includes a pair of rollers that rotate together in a state of pressure contact with each other, and a pressure contact portion of the roller pair in a sheet-like shape. A guiding means is provided at a predetermined position to guide the recording medium when the recording medium passes through the recording medium, and the guiding means and the supporting means are removable by fitting each other at least at a position other than the predetermined position. In the fitted state, the support means rotatably supports the guide means, and by making the guide means detachable in a simple manner, it is possible to dispose of paper jams or to remove the pressure roller. It facilitates cleaning and replacement.

Function: The present invention is configured as described above so that the guide means and the support means that rotatably support the guide means can be attached and detached by fitting.

By simply removing the guide means, the surface of the pressure roller that has been shielded by the guide means can be exposed, making it easier to deal with paper jams and to clean and replace the pressure roller.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

1 and 2 are sectional views of essential parts of a guide device according to an embodiment of the present invention. Components in FIGS. 1 and 2 denoted by the same numbers as in FIG. 3 have the same functions, and explanations thereof will be omitted.

In FIG. 1, the pair of heat rollers 1a and 1b are in pressure contact, and a fixing operation for fusing toner powder onto a recording medium (not shown) is shown. The heat roller pair 12L, 1b corresponds to a roller pair. 7 is a pressure roller support means rotatably supported at a first fulcrum 8 and rotatably supports the pressure roller 1b; 17 is a means for heating the pressure roller 1b supported by the pressure roller support means 7; A pressure spring 20 is rotatably supported by the second fulcrum 9, and a heating roller frame 18 rotatably supports the heating roller 112L. 1a, 1b; 10 is fixed to the heating roller frame; 10 is an upper guide means for the recording medium discharged from the heat roller pair 1a, 1b; and 14 is a lower guide means for the recording medium.

A pair of discharge rollers 12 and 13 further transports the recording medium guided by the upper guide means 1o and the lower guide means 14 and discharges it from the fixing device. Reference numeral 15 denotes a bearing that rotatably supports the lower paper ejection roller 13, and has a hole 16 in the center that engages with the shaft of the paper ejection roller 13, and the outer peripheral surface has a parallel plane symmetrically to the axis. It has been cut.

Since the lower guide means 14 fits with the outer circumference of the bearing 16,
A part of the hole that is slightly larger than the outer circumferential diameter is configured to have a cutout that is slightly larger than the parallel cut width, and the lower guide means 14 and the bearing 15 are fitted by inserting the cutout so that the inner surface of the cutout is aligned with the cut plane. match. In the fitted state, one end is supported by the bearing 15 and the other end abuts against the pressure roller support means 7 for positioning. Reference numeral 11 denotes a leaf spring that generates the force that causes the lower guide means 14 to come into contact with the pressure roller support means 7. Further, the heating roller frame 20 is fixed at a predetermined position by a latch mechanism (not shown). If the recording medium becomes clogged with the pressure roller 1b in such a state, the entrance guide means 18
Alternatively, it is efficient to remove the lower guide means 14 for processing.

FIG. 2 shows a state in which the launch mechanism of the embodiment shown in FIG. 1 is removed and the heating roller frame 20 is rotated clockwise about the second fulcrum 9. In this case, since the force of the leaf spring 11 that was pressing the lower guide means 14 is removed, the lower guide means 14 can rotate counterclockwise around the bearing 15, and is moved to the position shown by the dashed line. The lower guide means 14' that has arrived can be extracted through the notch and separated from the bearing 15 because the width of the parallel cut on the outer periphery of the bearing is smaller than the notch width of the lower guide means 14'. By establishing such a state, paper jams caught in the pressure roller 1b can be easily disposed of. In addition, by similar operation, pressure roller 1b
Since it is exposed, cleaning and replacement work becomes easier.

In this embodiment, an embodiment in which the support means is constituted by a bearing of a paper ejection roller is shown. In this case, a cost reduction effect is expected as no additional support means other than the bearing is required, but of course, providing a support means with the same function other than the bearing will also have a sufficient effect on improving operability. it is conceivable that. Further, regarding the roller pair, although the explanation has been made regarding the heat roller pair of the fixing device, it is fully conceivable that similar effects can be obtained even when other roller pairs are used.

Effects of the Invention As described above, the present invention includes a pair of rollers that cooperate with each other in a state of being pressed against each other, and a sheet-like recording medium that is positioned at a predetermined position when passing through the pressure contact portion of the pair of rollers. It has a guide means for guiding the recording medium, and a support means for rotatably supporting the guide means, and the guide means and the support means are attached and detached by fitting each other at least at a position other than the predetermined position. In the fitted state, the supporting means is rotatably supported, and it is possible not only to deal with paper jams but also to efficiently clean and replace the rollers. If it is configured with a bearing, it has extremely advantageous effects such as reducing the number of parts and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts of a guide device according to a first embodiment of the present invention, FIG. 2 is a diagram of another state of the embodiment of FIG. 1, and FIG. 3 is a sectional view of a conventional guide device. . 1a... Heating roller, 1b... Pressure roller, 4... Halogen lamp, End... Pressure roller support means, 1Q...... Upper guide means, 1
1...Plate spring, 14...Lower guide means, 15...Bearing, 17...Pressure spring,
1st... Entrance guidance means. Name of agent: Patent attorney Toshio Nakao and 1 other person7-
Ka 2 Sho, Laura Gen” Reference Means I4- Lower Guide Means 18- Population Guide Child Actor Figure 1〃 Figure 2

Claims (3)

[Claims] (1) a pair of rollers that rotate together while being in pressure contact with each other; a guide means that is located at a predetermined position and guides the sheet-like recording medium when the sheet-like recording medium passes through the pressure-contact portion of the pair of rollers; support means rotatably supporting the guide means, the guide means and the support means are capable of being attached and detached by fitting each other at least at a position other than the predetermined position, and in the fitted state, A guide device characterized in that the support means rotatably supports the guide means. (2) The guide means has a round hole with a notch formed in a part, and the support means is constituted by a cylinder having notch planes parallel to each other about the axis, and the part between the notches is 2. The guide device according to claim 1, wherein the round hole and the cylinder fit together by fitting parallel planes of the cylinder along an inner surface. (3) The guide device according to claim 1 or 2, wherein the support member is constituted by the outer periphery of the guide bearing of the paper ejection roller.