Fixing device

Claim 2

A fixing device wherein a sheet carrying a toner image is passed between the nip of a pair of rollers, at least one of which is heated, thereby fixing the toner image on the member, the improvement comprising: means mounting the rollers for relative radial movement between a pressure-contact relationship and a non-pressure-contact relationship; a first gear mounted for rotational movement; a second gear meshing with said first gear and revolvable about said first gear, so that the center of said second gear moves around said first gear; means providing relative revolving movement between said first and second gears, in response to said rotation of said second gear, for revolving said second gear around said first gear from a first to a second position; and pressure applying means coupled to said second gear and operatively associated with at least one of said rollers for moving said rollers into said pressure-contact relationship in response to revolving movement of said second gear to said first position, and into said non-pressure-contact relationship in response to revolving movement of said second gear to said second position.

Claim 3

A fixing device as set forth in claim 1, wherein said means for revolving said second gear includes means for producing different peripheral speeds of said first and second gears.

Claim 4

A fixing device as set forth in claim 2, wherein said different speed producing means includes means for controlling the rotation of said first rotatable gear.

Claim 5

A fixing device as set forth in claim 3, wherein said control means includes means for stopping the rotation of said first rotatable gear.

Claim 6

A fixing device as set forth in claim 2, wherein said different speed producing means includes clutch means for connecting said first rotatable gear to a fixed member.

Claim 7

A fixing device as set forth in claim 5, further comprising means for detecting the pressure-contact relationship of said rollers; and means coupled to said detecting means, for stopping the revolving movement of said second rotatable gear when said pair of rollers are in said pressure-contact relationship, wherein, when said stopping means stops said second gear, said clutch means releases said first gear from said fixed member to allow free rotation thereof.

Claim 8

A fixing device as set forth in claim 1, wherein said means for rotating said second gear comprises a third gear coupled to one of said rollers and meshing with said second gear, and means for driving said third gear.

Claim 9

A fixing device as set forth in claim 1, wherein said pressure applying means includes a rotatable member in contact with one of said rollers and being movable in response to revolving movement of said second gear.

Claim 10

A fixing device as set forth in claim 1, further comprising means for stopping revolving movement of said second gear and for releasably holding said second gear in said first position.

Claim 11

A fixing device as set forth in claim 9, wherein said stopping means includes means for detecting a position of said second gear and means connected to said detecting means for locking said second gear at said first position so as to stop said second gear from further revolving movement.

Claim 12

A fixing device as set forth in claim 10, wherein said locking means is actuated by solenoid means.

Claim 13

A fixing device as set forth in claim 11, wherein said means for revolving said second gear includes means for urging said second gear toward said second position when said locking means is deactuated.

Claim 14

A fixing device as set forth in claim 1, wherein said means for revolving said second gear includes means for stopping rotation of said first gear, so as to revolve said rotating second gear around said stopped first gear toward said first position, and spring means for urging said second rotatable gear to revolve toward said second position.

Claim 15

A fixing device as set forth in claim 13, further comprising means for locking said second gear in said first position to hold it against revolving movement, thereby maintaining said pair of rollers in said pressure-contact relationship, and solenoid means for being energized to actuate said locking means, wherein said spring means is operative to revolve said second rotatable gear toward said second position when said solenoid is not deenergized.

Claim 16

A fixing device as set forth in claim 13, further comprising means for heating an outer surface of one of said rollers.

Claim 17

A fixing device wherein a sheet carrying a toner image is passed between the nip of a pair of rollers, at least one of which is heated, thereby fixing the toner image on the member, the improvement comprising: means mounting the rollers for relative radial movement between a pressure-contact relationship and a nonpressure-contact relationship; a first gear mounted for rotational movement; a second gear meshing with said first gear and revolvable about said first gear so that the center of said second gear moves around said first gear; means providing a first relative rotational movement between said first and second gears for revolving said second gear around said first gear toward a first position; means providing a second relative rotational movement between said first and second gears for revolving said second gear around said first gear, in an opposite direction, toward a second position; and means coupled to said second gear and operatively associated with at least one of said rollers for controlling said relative movement between said rollers in response to revolving movement of said second gear so that said rollers are placed into said pressure-contact relationship in response to revolving movement of said second gear to said first position, and so that said pair of rollers move into said non-pressure-contact relationship in response to revolving movement of said second gear to said second position.

Claim 18

A fixing device wherein a sheet carrying a toner image is passed between the nip of a pair of rollers, at least one of which is heated, thereby fixing the toner image on the member, the improvement comprising: means mounting the rollers for relative radial movement between a pressure-contact relationship and a nonpressure-contact relationship; a first gear mounted for rotational movement; a second gear meshing with said first gear and revolvable about said first gear so that the center of said second gear moves around said first gear; means providing a first relative rotational movement between said first and second gears for revolving said second gear around said first gear toward a first position; means providing a second relative rotational movement between said first and second gears for revolving said second gear around said first gear, in an opposite direction, toward a second position; and means coupled to said second gear and operatively associated with at least one of said rollers for controlling said relative movement between said rollers in response to revolving movement of said second gear so that said rollers are placed into said pressure-contact relationship in response to revolving movement of said second gear to said first position, and so that said pair of rollers move into said non-pressure-contact relationship in response to revolving movement of said second gear to said second position.

Claim 19

A fixing device for an electrogaphic machine comprising: a pair of abutting rollers adapted to pass therethrough a sheet carrying a toner image; means for heating at least one of said rollers; a first gear mounted for rotation at a predetermined position; a second gear meshing with said first rotatable gear; means providing relative revolving movement between said first and second gears for revolving said second gear around said first gear, said revolving means including means for rotating said second gear, and means for stopping rotation of said first gear to control the revolution of said second gear thereabout; supporting means for rotatably supporting said second gear, wherein said supporting means is mounted for revolving movement with said second gear in response to rotational movement of said second gear; and means connected to said supporting means and operatively associated with at least one of said rollers for producing relative radial movement between said rollers in response to said revolving-movement of said supporting means, so that said rollers are selectively placed into a pressure-contact relationship or a non-pressure-contact relationship.

Claim 20

A fixing device for an electrogaphic machine comprising: a pair of abutting rollers adapted to pass therethrough a sheet carrying a toner image; means for heating at least one of said rollers; a first gear mounted for rotation at a predetermined position; a second gear meshing with said first rotatable gear; means providing relative revolving movement between said first and second gears for revolving said second gear around said first gear, said revolving means including means for rotating said second gear, and means for stopping rotation of said first gear to control the revolution of said second gear thereabout; supporting means for rotatably supporting said second gear, wherein said supporting means is mounted for revolving movement with said second gear in response to rotational movement of said second gear; and means connected to said supporting means and operatively associated with at least one of said rollers for producing relative radial movement between said rollers in response to said revolving-movement of said supporting means, so that said rollers are selectively placed into a pressure-contact relationship or a non-pressure-contact relationship.

Claim 21

A fixing device for an electrographic machine comprising: a pair of abutting rollers adapted to pass therethrough a sheet carrying a toner image; means for heating at least one of said rollers; a planetary gear, and two rotatable gears, said planetary gear being engaged with said two rotatable gears and revolvable around one of said rotatable gears; means for rotatably driving one of said two rotatable gears; means for revolving said planetary gear in response to said rotation of one of said gears; and means coupled to said planetary gear and operatively associated with at least one of said rollers for producing relative radial movement between said rollers in response to revolving movement of said planetary gear, wherein said rollers are selectively placed into a pressure-contact relationship or a non-pressure-contact relationship with each other.

Claim 22

A fixing device for an electrographic machine comprising: a pair of abutting rollers adapted to pass therethrough a sheet carrying a toner image; means for heating at least one of said rollers; a planetary gear, and two rotatable gears, said planetary gear being engaged with said two rotatable gears and revolvable around one of said rotatable gears; means for rotatably driving one of said two rotatable gears; means for revolving said planetary gear in response to said rotation of one of said gears; and means coupled to said planetary gear and operatively associated with at least one of said rollers for producing relative radial movement between said rollers in response to revolving movement of said planetary gear, wherein said rollers are selectively placed into a pressure-contact relationship or a non-pressure-contact relationship with each other.

Claim 23

A fusing device, for use with an electrographic machine to fix a heat-fusible image on a sheet member comprising: a pair of rollers adapted to pass the sheet member therethrough, at least one of said rollers having a resilient surface; a first member mounted for rotational movement; a second rotatable member engaged with said first member for revolving movement thereabout; means for rotatably supporting said second member, wherein said supporting means revolves with said second member; means for causing said rovolving movement of said second member and said supporting means, said revolving means including means for rotating said second member and means for controlling the rotation of said first member; and means connected to said supporting means and operatively associated with at least one of said rollers for producing relative radial movement between said rollers in response to said revolving movement of said supporting means, so that said rollers are placed into a first position wherein they are in a pressure-contact relationship with each other to apply pressure to the sheet member so as to fix the heat-fusible image, and a second position wherein they are in a non-pressure-contact relationship, thereby preventing deformation of said resilient surface.

Claim 24

A fusing device, for use with an electrographic machine to fix a heat-fusible image on a sheet member comprising: a pair of rollers adapted to pass the sheet member therethrough, at least one of said rollers having a resilient surface; a first member mounted for rotational movement; a second rotatable member engaged with said first member for revolving movement thereabout; means for rotatably supporting said second member, wherein said supporting means revolves with said second member; means for causing said rovolving movement of said second member and said supporting means, said revolving means including means for rotating said second member and means for controlling the rotation of said first member; and means connected to said supporting means and operatively associated with at least one of said rollers for producing relative radial movement between said rollers in response to said revolving movement of said supporting means, so that said rollers are placed into a first position wherein they are in a pressure-contact relationship with each other to apply pressure to the sheet member so as to fix the heat-fusible image, and a second position wherein they are in a non-pressure-contact relationship, thereby preventing deformation of said resilient surface.

Claim 25

A fusing device as set forth in claim 19, wherein said first and second rotatable members are first and second gears, respectively, engaging with each other.