JP3403448B2 - Rotation angle conversion mechanism and fixing device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle converting mechanism for interlocking the opening / closing of a cover provided on a machine frame of an image forming apparatus with a drive releasing mechanism of a fixing roller pair.

[0002]

2. Description of the Related Art For example, as a fixing device used in an image forming apparatus such as a copying machine or a printer, fixing is performed by passing a transfer sheet between a pair of fixing rollers pressed against each other to fix an unfixed image on the transfer sheet. Although the device is well known in the art, in a general fixing device, one roller of a fixing roller pair is driven, and normally, the drive gear is engaged with a gear integrally provided on the drive side roller coaxially. The drive-side roller is also rotated accordingly.

In such a fixing device, the transfer paper may be jammed between the pair of rollers. In order to deal with this paper jam, conventionally, a knob or the like is provided at the shaft end of the driving side roller of the pair of rollers, and the knob is pulled to separate the gear provided on the driving side roller from the driving gear. After the mesh is released, the knob is turned and the drive side roller is rotated to remove the jammed paper.

However, in the conventional fixing device, in order to remove the jammed paper, it is necessary to perform two operations of pulling the knob and rotating the knob, which is difficult and difficult to use. is there.

In order to solve such a problem, a method may be considered in which the transmission of the driving force is automatically released when the jam processing cover provided in the image forming apparatus is opened.

For example, when the drive transmission mechanism for transmitting the driving force to the driving side roller has a gear train composed of a plurality of gears, one of the gear trains has a drive transmission position for transmitting the driving force, A gear supporting member that is movably provided in a drive releasing position for releasing the transmission of the driving force and that supports the movable gear, and a jam that can be opened and closed with a point on the machine frame of the image forming apparatus as a fulcrum. A configuration is conceivable in which the cover for processing is connected, the opening and closing of the cover and the gear support member are interlocked, and the driving force is transmitted to and released from the driving roller.

However, the depth at which the gear meshes with other gears for transmitting the driving force is very small. Therefore, if the cover and the gear support member are simply connected, the gear support member will be too sensitive to the opening / closing operation of the cover. That is, if the cover is loosely attached or the cover is not closed tightly, the gears may not mesh well and the driving force may not be transmitted. Further, when the cover is closed or when the cover is opened to the maximum position, unnecessary force may be applied to the gear and the supporting member. In order to prevent such a problem, the gear support member is stopped at the drive transmission position until the cover is opened to a certain angle, and when the cover is opened further, the gear support member moves to the drive release position. Further, it is convenient if the gear support member does not move more than necessary even if the cover is opened over a certain angle.

Such a rotation angle converting mechanism in which the other member is rotated when a certain member is rotated at a certain angle and the other member is stopped when the certain member is rotated at another angle, Not limited to the fixing device of the forming device,
It can be used in a wide range of fields.

[0009]

The present invention has been described above.
The rotation angle conversion mechanism, in which the other member rotates when a certain member rotates at a certain angle, and the other member stops when the certain member rotates at another angle, has a simple structure and is small in size and low in cost. The challenge is to provide in.

Further, the present invention solves the problem that the conventional fixing device is difficult to operate during jam processing and is difficult to use by using the above rotation angle converting mechanism, and the jam processing is easy to perform with a simple operation. An object is to provide a fixing device.

[0011]

According to the present invention, in the rotation angle conversion mechanism having at least one rotation center, the above-mentioned problems include a first member rotating about the rotation center and a rotation center different from the rotation center. The second member has a second member, and a third member that has a long groove fitted to one fulcrum and rotates and slides with the fulcrum as a reference. One end of the third member is pivoted to a free end of the first member. And the other end is rotatably and slidably inserted in the long groove of the second member so that the first member can rotate at a predetermined angle and the fulcrum position of the third member and the length of the long groove. Is set, and the position of the rotation center of the second member and the length of the long groove are set so that the other end of the third member can slide in the long groove of the second member when the first member rotates. And whether the first member is in a predetermined first position The fulcrum of the third member is provided so as to be located substantially on the movement line of the free end when rotated to a second position by a certain range of angle, and the movement of the third member during rotation at the certain range of angle. The rotation center of the second member is provided so that the direction and the direction of the long groove of the second member are substantially parallel to each other, and the rotation of the first member from the first position to the second position causes the second member to rotate. Is not rotated, and the second member is rotated when the first member is rotated from the first position to a position other than the second position, which is solved by the rotation angle conversion mechanism.

In order to solve the above-mentioned problems, the present invention has a fixing roller pair mounted in an image forming apparatus and pressed against each other so that one roller of the roller pair is driven. In the fixing device described above, a drive release mechanism that transmits and releases the drive force to the drive side roller,
A cover that can be opened and closed with one point on the machine frame of the image forming apparatus as a fulcrum is provided, and a first member that rotates about at least one rotation center and a second member that has a rotation center different from the rotation center A third member provided with a long groove fitted to one fulcrum, and rotating and sliding on the basis of the fulcrum.
One end of the member is pivotally connected to the free end of the first member, and the other end is rotatably and slidably inserted in the long groove of the second member so that the first member can rotate at a predetermined angle. The fulcrum position of the third member and the length of the long groove are set in the second member so that the other end of the third member can slide in the long groove of the second member when the first member rotates. The position of the center of rotation and the length of the long groove are set, and the first member is positioned substantially on the movement line of the free end when the first member is rotated by a certain range of angle from the predetermined first position to the second position. Is provided with a fulcrum of the third member, and the second member is rotated so that the moving direction of the third member and the direction of the long groove of the second member are substantially parallel when rotating at an angle within the certain range. A center is provided and from the first position of the first member Rotation having at least one rotation center such that the second member does not rotate when rotated up to the second position, and the second member rotates when the first member rotates from a position other than the first position to the second position. An angle conversion mechanism is provided,
It is proposed that the first member is connected to the cover, the third member is connected to the drive release mechanism, and the drive force to the drive-side roller is transmitted and released in conjunction with opening and closing of the cover. To do.

[0013]

When the first member rotates within a certain angle range, the third member
The member slides while rotating about the fulcrum to rotate the second member. Then, when the first member rotates within a range of angles other than that, the third member slides with almost no rotation. As a result, the other end of the third member is the second
The second member does not rotate by sliding in the same direction as the long groove of the member.

Other functions will be apparent from the description of the embodiments below.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of a rotation angle conversion mechanism of the present invention.

In the rotation angle conversion mechanism 30 shown in FIG.
The rotating member 1 can rotate around the stud pin 2 as a fulcrum. The swinging member 3 can swing about the stud pin 4 as a fulcrum, and the slit 3a is provided along the longitudinal direction thereof. The connecting member 6 is provided with a slit 6a along its longitudinal direction. The slit 6a is fitted to the stud pin 5, and the connecting member 6 is slidably and rotatably supported. One end of the connecting member 6 is pivotally attached to the free end of the rotating member 1 by a pin 7.
A shaft 8 is provided at the other end of the connecting member 6, and the shaft 8
Is fitted in the slit 3a of the swinging member 3 and is slidable and rotatable.

As shown in FIG. 2, it is assumed that the rotary member 1 is rotated by a certain range of angle from the position indicated by the chain double-dashed line to the position indicated by the solid line. Then, one end of the rotary member 1 is pivotally attached to the free end of the rotary member 1 and is supported by the stud pin 6.
Slides while rotating counterclockwise in the figure with the stud pin 6 as a fulcrum. That is, the pin 7 moves diagonally downward right. On the other hand, the shaft 8 moves diagonally upward to the left. At this time, the distance L ₁ between the pin 7 and the stud pin 5 is smaller than the distance L ₂ between the shaft 8 and the stud pin 5, so that the pin 7
The movement amount of the shaft 8 is relatively large with respect to the movement amount of
Makes the swinging member 3 swing clockwise in the figure while sliding in the slit 3a of the swinging member. As a result, when the rotating member 1 rotates from the position shown by the two-dot chain line to the position shown by the solid line, the swing member 3 swings from the position shown by the two-dot chain line to the position shown by the solid line.

Next, in FIG. 3, it is assumed that the rotary member 1 is rotated by a certain range of angle from the position indicated by the chain double-dashed line to the position indicated by the solid line. In this range, since the stud pin 5 is located almost on the line on which the pin 7 moves, the connecting member 6 hardly rotates and only slides diagonally downward. At this time, since the sliding direction of the connecting member 6 and the direction of the slit 3a of the swinging member 3 are substantially parallel to each other, the shaft 8 provided at the end of the connecting member 6 has the slit 3a.
The inside of a is slid downward, and the swinging member 3 does not swing and remains stopped at approximately the same position.

In the rotation angle converting mechanism 30 of this embodiment, when the rotating member 1 is rotated to the position shown by the solid line in FIG. 3, the stud pin 5 comes into contact with the end of the slit 6a of the connecting member 6,
The rotary member 1 can no longer rotate clockwise. However, if the connecting member 6 is elongated and the slit 6a is elongated, the rotating member 1 can rotate with the stud pin 2 as a fulcrum. The operation of the rotation angle conversion mechanism 30 in that case is such that when the rotating member 1 is rotated clockwise from the position shown by the solid line in FIG. 3 to the position shown in FIG. 1, the swinging member 3 is shown in FIG. Swings counterclockwise from the position,
Return to the position shown in FIG. As described above, in the rotation angle conversion mechanism 30 of the present embodiment, when the rotating member 1 rotates within a certain angle range, the swinging member 3 swings, and the rotating member 1 rotates within a range of other angles. Occasionally, the rocking member 3 does not rock and stops at about the same position.

The operation of the oscillating member 3 when the rotating member 1 rotates counterclockwise in the figure is the reverse of the above description.

FIG. 4 is a partial plan view showing the vicinity of the jam clearance cover of the image forming apparatus equipped with the fixing device of the embodiment of the present invention. As shown in FIG. 4, the main body 50 of the image forming apparatus is provided with a cover 13 for jam clearance. Bracket 21 fixed to cover 13
Is rotatably attached to the apparatus main body 50 by a shaft 22. Therefore, the cover 13 can be opened and closed with the shaft 22 as a fulcrum. In addition, the main body 5 of the image forming apparatus
At 0, a rotation angle conversion mechanism 30 'is attached. The rotation angle converting mechanism 30 'includes a rotating arm 31 and a swinging arm 3.
3 and a connecting arm 36. Rotating arm 3
The reference numeral 1 is fixed to one side of the above-mentioned bracket 21, and can rotate about a shaft 22 as a fulcrum. Swing arm 3
3 is attached to the apparatus main body 50 by a shaft 34, and the shaft 34
It is possible to swing about. A slit 33a is provided along the longitudinal direction of the swing arm 33. Further, a slit 36a is provided along the longitudinal direction of the connecting arm 36, and this slit 36a is fitted to the shaft 35 provided in the apparatus main body 50, so that the connecting arm 3
6 is supported on the apparatus main body 50 so as to be rotatable and slidable. On the other hand, the shaft 3 is attached to one end of the connecting arm 36.
8 is provided, and the shaft 38 is the slit 33 of the swing arm 33.
It is fitted to a. The shaft 38 is slidable and rotatable in the slit 33a of the swing arm 33. Therefore, the swing arm 33 and the connecting arm 36 are slidably and rotatably connected to each other. A circular notch 37 is formed in the end of the connecting arm 36 opposite to the shaft 38. Then, the protrusion 31a of the rotating arm 31 is fitted into the notch 37, and the rotating arm 31 and the connecting arm 36 are rotatably connected to each other.

By the way, the rotating arm 31 and a part of the bracket 21 to which the rotating arm 31 is fixed are provided in the rotating member 1 in FIG.
Equivalent to. The shaft 22 corresponds to the stud pin 2 in FIG. The swing arm 33 corresponds to the swing member 3 in FIG. The shaft 34 corresponds to the stud pin 4 in FIG. Furthermore, the connecting arm 3
6 corresponds to the connecting member 6 in FIG. 1, and the shaft 35 corresponds to the stud pin 5.

The operation of the rotation angle conversion mechanism 30 'when the cover 13 is opened is shown by the solid line in FIG. 2 from the state in which the rotation angle conversion mechanism 30 shown in FIGS. The operation is the same as that for changing to the state and further changing to the state shown by the solid line in FIG.

The rotation angle conversion mechanism 3 shown in FIG.
The state of 0'corresponds to the state of the rotation angle conversion mechanism 30 shown in FIG. That is, the shaft 35 contacts the end of the slit 36a of the connecting arm 36, and the cover 13 cannot rotate any further in the clockwise direction. Therefore, the position shown in FIG. 4 is the maximum open position of the cover 13.

The operation of the rotation angle conversion mechanism 30 'when the cover 13 is closed is the reverse of the operation of the rotation angle conversion mechanism 30 described with reference to FIGS. 1 to 3, and is shown by the solid line in FIG. The state changes from the state shown by the solid line in FIG. 2 to the state shown in FIG.

On the other hand, one end of the wire rope 17 is locked at a position near the shaft 34 of the swing arm 33. The wire rope 17 passes through the guide tube 23, and the other end of the wire rope 17 is locked to a gear support bracket of a driving force transmission mechanism described later. Therefore, the cover 13 and the gear support bracket are connected by the rotation angle conversion mechanism 30 ′ and the wire rope 17.

FIG. 5 is a side view showing a driving force transmission mechanism for transmitting the driving force to the driving side roller of the fixing device.

In FIG. 5, a drive gear 15 driven by a motor (not shown) comprises two gears 10a and 10b.
Is meshed with a gear 10a on the outer side of a two-stage gear 10 having a coaxial axis. A gear support bracket 18 is swingably attached to the shaft 9 of the two-stage gear 10. A swing gear 11 is pivotally mounted on the gear support bracket 18 so as to mesh with a gear 10b inside the two-stage gear. Further, the spring 1 is attached to the lower end of the gear support bracket 18.
One end of 4 is locked. The other end of the spring 14 is locked to a body frame (not shown), and the swing gear 11
Urges the gear support bracket 18 so as to mesh with the idle gear 12. And the idle gear 12 is
It is meshed with a driven gear (not shown) provided coaxially and integrally with the drive side roller of the fixing device.

By the way, at the lower end of the gear support bracket 18, the other end of the wire rope 17, one end of which is locked to the swing arm 33 of the rotation angle converting mechanism 30 'shown in FIG. 4, is locked. .

When the cover 13 shown in FIG. 4 is closed, the rotation angle conversion mechanism 30 'is in the state of the rotation angle conversion mechanism 30 shown in FIG. 1, and the swing arm 33 is the swing member in FIG. 3 is located at the right end of the swing range.
Therefore, the gear support bracket 18 connected to the swinging arm 33 by the wire rope 17 is not pulled by the wire rope 17 and is acted by the spring 14 so that the gear support bracket 18 shown in FIG.
In the position shown by the solid line, the swing gear 11 is meshed with the idle gear 12. Therefore, the driving force of the motor (not shown) is transmitted to the driving side roller (not shown) of the fixing device.

On the other hand, when the cover 13 is opened, the rotation angle conversion mechanism 30 'operates like the rotation angle conversion mechanism 30 described with reference to FIGS. 1, 2 and 3, and the swing arm 33 swings clockwise in the drawings. Move. As a result, the wire rope 17 whose one end is locked to the swing arm 33 is pulled leftward in FIGS. 4 and 5, and the gear support bracket 18 acts on the shaft 9 as a fulcrum against the biasing force of the spring 14. It rotates counterclockwise in the figure and rotates to the position shown by the chain double-dashed line. And
The rocking gear 11 also rotates to the position shown by the chain double-dashed line, and the meshing with the idle gear 12 is released. As a result, the transmission of the driving force from the motor (not shown) is released. Therefore,
When a paper jam occurs in the fixing device, the cover 13 shown in FIG. 4 is opened to perform the jam processing, the transmission of the driving force to the driving side roller of the fixing device is automatically released, and the user The jammed paper can be removed by simply turning a knob (not shown) provided at the shaft end of the driving roller. That is, it is not necessary to perform the two operations of releasing the transmission of the driving force to the driving side roller by pulling the knob and rotating the knob, so that the jam processing can be easily performed. Further, since the transmission of the driving force to the driving side roller is automatically released, the torque for turning the driving side roller of the fixing device and the idle gear 12 meshed with this is sufficient for turning the knob. You can turn the knob lightly to reduce the force required to clear the jam.

By the way, when the closed cover 13 is opened up to a certain angle, that is, the rotation angle conversion mechanism 30 'is in the state shown by the solid line in FIG. 2 from the state of the rotation angle conversion mechanism 30 shown in FIG. When the cover 13 is opened in a range that changes to, the swing arm 33 swings clockwise in the drawing to rotate the gear support bracket 18, and the transmission of the driving force is released. However, even if the cover 13 is further opened, the swing arm 33 is stopped at a substantially constant position like the swing member 3 described in FIG. 3, so that the gear support bracket 18 in FIG. It is almost stopped at the position indicated by the chain line. Therefore, even if the cover 13 is opened more than a certain angle, the gear support bracket 18 does not rotate more than necessary, so that the gear support bracket 18 and the swing gear 1 are not rotated.
The space for rotating 1 is small, which is advantageous in the layout of the driving force transmission mechanism. Also, the swing gear 11
The spring 14 for biasing the idle gear 12 to the idle gear 12 is not pulled too much, so the spring 1
There is a margin in the design of the spring 14 such that the life of the spring 4 is extended.

[0034]

As described above, the rotation angle conversion mechanism of the present invention is composed of three parts. When one member rotates at a certain angle, the other member rotates, and the other member does not rotate. It is possible to provide a rotation angle conversion mechanism in which the other member is stopped at the time of rotation at a small size and at a low cost.

According to the fixing device of the present invention, when the cover for jamming is opened when a paper jam occurs, the transmission of the driving force to the driving side roller of the fixing device is automatically released, so that the driving side roller is An operation such as pulling a knob provided at the shaft end of is unnecessary, and jam can be easily removed. Also, less force is needed to clear the jam.

According to the structure of claim 2, the movable gear and its supporting member do not move more than necessary, which is advantageous in the layout of the drive system. Further, there is a margin in the design of the biasing means for biasing the movable gear to the drive transmission position.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a rotation angle conversion mechanism of the present invention.

FIG. 2 is a diagram for explaining the operation of the rotation angle conversion mechanism shown in FIG.

FIG. 3 is a diagram for explaining the operation of the rotation angle conversion mechanism likewise shown in FIG. 1.

FIG. 4 is a partial plan view showing the vicinity of a jam clearance cover of an image forming apparatus to which an embodiment of the fixing device of the present invention is mounted.

FIG. 5 is a side view showing a driving force transmission mechanism of the fixing device.

[Explanation of symbols]

10 two-stage gear 11 Swing gear 12 idle gear 13 Jam processing cover 14 spring 15 drive gear 17 wire rope 18 Gear support bracket 22, 34, 35 axes 30, 30 'Rotation angle conversion mechanism 31 rotating arm 33 Swing arm 36 connecting arm 50 Image forming apparatus main body

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 13/20 G03G 15/00 550 G06G 15/20 F16H 21/10

Claims (2)

(57) [Claims] 1. A rotation angle conversion mechanism having at least one rotation center, wherein a first member that rotates at the rotation center, a second member that has a rotation center different from the rotation center, and one fulcrum are fitted together. Third groove that has a long groove that rotates and slides around the fulcrum
A member, one end of the third member is pivotally connected to a free end of the first member, and the other end is rotatably and slidably inserted in a long groove of the second member, The third member is provided so that the member can rotate at a predetermined angle.
The fulcrum position of the member and the length of the long groove are set, and the position of the rotation center of the second member so that the other end of the third member can slide in the long groove of the second member when the first member rotates. And the length of the long groove is set, and the third member is positioned so as to be substantially on the line of movement of the free end when the first member is rotated by a certain range of angle from the predetermined first position to the second position. A fulcrum of the member is provided, and the rotation center of the second member is provided so that the moving direction of the third member and the direction of the long groove of the second member are substantially parallel to each other when rotating at an angle within the certain range. , The second member does not rotate when the first member rotates from the first position to the second position, and the second member rotates when the first member rotates from a position other than the first position to the second position. A rotation angle conversion mechanism characterized by: 2. A fixing device which is mounted on an image forming apparatus and has a pair of fixing rollers which are in pressure contact with each other, and which drives one of the pair of rollers, wherein the driving side roller is driven. A drive releasing mechanism that transmits and releases force, and a cover that can be opened and closed with one point on the machine frame of the image forming apparatus as a fulcrum are provided, and a first member that rotates about at least one rotation center, and the rotation center A second member having a rotation center different from that of the first member, and a third member having a long groove fitted to one fulcrum and rotating and sliding on the basis of the fulcrum, one end of the third member being the first member. Is pivotally connected to the free end of the third member, the other end of which is rotatably and slidably inserted in the long groove of the second member, and the fulcrum position of the third member allows the first member to rotate at a predetermined angle. And the length of the long groove is set. The position of the rotation center of the second member and the length of the long groove are set so that the other end of the third member can slide in the long groove of the second member when the member rotates, and the first member is The fulcrum of the third member is provided so as to be substantially on the moving line of the free end when rotated from a predetermined first position to a second position by an angle in a certain range, The rotation center of the second member is provided so that the moving direction of the third member and the direction of the long groove of the second member are substantially parallel to each other, and the rotation center of the first member from the first position to the second position is set. A rotation angle conversion mechanism having at least one rotation center configured such that the second member does not rotate during rotation, and the second member rotates during rotation of the first member other than the first position and the second position. And the first member is the cover Is connected, said third member being connected to the driving release mechanism fixing device driving force to said driving roller in conjunction with opening and closing of the cover is characterized in that it is canceled transmission and transmission.