Presser, fixing device, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-11099510-B2
Application number	US-202016892629-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Jul 17, 2019
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A presser presses a pressed object and includes a first rotation shaft and a pressurizing portion that is supported by the first rotation shaft and pivots about the first rotation shaft. A depressurizing portion is supported by a second rotation shaft and pivots about the second rotation shaft with respect to the pressurizing portion. The depressurizing portion includes an engagement. An interlock lever includes an opening that engages the engagement. The depressurizing portion pivots to switch between a pressurization state in which the engagement contacts and presses the opening to cause the pressurizing portion to press the pressed object and a depressurization state in which the pressurization state is released. The depressurizing portion pivots to define a gap between the engagement and the opening in a moving direction in which the engagement moves.

First claim

What is claimed is:

1. A presser configured to press a pressed object, the presser comprising:
a first rotation shaft;
a pressurizing portion supported by the first rotation shaft and configured to pivot about the first rotation shaft;
a second rotation shaft;
an interlock lever including a circular opening having a first diameter; and
a depressurizing portion supported by the second rotation shaft and configured to pivot about the second rotation shaft with respect to the pressurizing portion, the depressurizing portion including a projection penetrating the opening, a widest portion of the projection having a second diameter sufficiently smaller than the first diameter such that a gap exists in all directions between the projection and the opening when the presser is in a depressurizing state to allow the projection to move the set distance within the circular opening and, as the depressurizing portion pivots to switch the presser from the depressurizing state to a pressurization state, the projection freely moves a set distance within the circular opening before the presser is in the pressurization state in which the projection contacts and presses the opening to cause the pressurizing portion to press the pressed object.

2. The presser according to claim 1 , wherein the opening defines a circle having a diameter greater than a diameter of the projection.

3. The presser according to claim 1 , wherein the interlock lever further includes a recess configured to engage the second rotation shaft as the depressurizing portion pivots.

4. The presser according to claim 3 , wherein the recess is configured to engage the second rotation shaft to secure the interlock lever in the pressurization state.

5. The presser according to claim 3 , further comprising:
a spring to which the interlock lever is anchored,
wherein the interlock lever is configured to engage the second rotation shaft and the depressurizing portion.

6. The presser according to claim 5 , wherein the interlock lever further includes a hook extending from the recess, the hook configured to be hooked with the spring.

7. The presser according to claim 1 , wherein at least one of the projection and the opening includes an arc portion having a curvature.

8. The presser according to claim 7 ,
wherein the projection is configured to contact and press the opening at the arc portion.

9. The presser according to claim 1 , wherein the second diameter is sufficiently smaller than the first diameter such that, in at least a direction in which a force is exerted on the opening and the projection as the depressurizing portion pivots, the gap exists between the projection and the opening when the presser is in the depressurizing state to allow the projection to move the set distance within the circular opening in the direction of the force.

10. A fixing device comprising:
a first nip former;
a second nip former disposed opposite the first nip former to form a fixing nip between the first nip former and the second nip former, the fixing nip through which a recording medium bearing an image is conveyed; and
a presser configured to press at least one of the first nip former and the second nip former, the presser including:
a first rotation shaft;
a pressurizing portion supported by the first rotation shaft and configured to pivot about the first rotation shaft;
a second rotation shaft;
an interlock lever including a circular opening having a first diameter; and
a depressurizing portion supported by the second rotation shaft and configured to pivot about the second rotation shaft with respect to the pressurizing portion, the depressurizing portion including a projection penetrating the opening, a widest portion of the projection having a second diameter sufficiently smaller than the first diameter such that a gap exists in all directions between the projection and the opening when the presser is in a depressurizing state to allow the projection to move the set distance within the circular opening and, as the depressurizing portion pivots to switch the presser from the depressurizing state to a pressurization state, the projection freely moves a set distance within the circular opening before the presser is in the pressurization state in which the projection contacts and presses the opening to cause the pressurizing portion to press the at least one of the first nip former and the second nip former and a depressurization state in which the pressurization state is released.

11. The fixing device according to claim 10 , further comprising a pressure body mounted on the first nip former and configured to press the first nip former, the pressure body configured to be pressed by the pressurizing portion.

12. The fixing device according to claim 10 ,
wherein the first nip former includes a pressure roller.

13. The fixing device according to claim 10 ,
wherein the second nip former includes a fixing belt.

14. The fixing device according to claim 10 ,
wherein the pressurizing portion includes a pressure arm.

15. The fixing device according to claim 10 ,
wherein the depressurizing portion includes a depressure lever.

16. The fixing device according to claim 10 , wherein the second diameter is sufficiently smaller than the first diameter such that, in at least a direction in which a force is exerted on the opening and the projection as the depressurizing portion pivots, the gap exists between the projection and the opening when the presser is in the depressurizing state to allow the projection to move the set distance within the circular opening in the direction of the force.

17. An image forming apparatus comprising:
an image bearer configured to bear an image; and
a fixing device configured to fix the image on a recording medium, the fixing device including:
a first nip former;
a second nip former disposed opposite the first nip former to form a fixing nip between the first nip former and the second nip former, the fixing nip through which the recording medium bearing the image is conveyed; and
a presser configured to press at least one of the first nip former and the second nip former, the presser including:
a first rotation shaft;
a pressurizing portion supported by the first rotation shaft and configured to pivot about the first rotation shaft;
a second rotation shaft;
an interlock lever including a circular opening having a first diameter; and
a depressurizing portion supported by the second rotation shaft and configured to pivot about the second rotation shaft with respect to the pressurizing portion, the depressurizing portion including a projection penetrating the opening, a widest portion of the projection having a second diameter sufficiently smaller than the first diameter such that a gap exists in all directions between the projection and the opening when the presser is in a depressurizing state to allow the projection to move the set distance within the circular opening and, as the depressurizing portion pivots to switch the presser from the depressurizing state to a pressurization state, the projection freely moves a set distance within the circular opening before the presser is in the pressurization state in which the projection contacts and presses the opening to cause the pressurizing portion to press the at least one of the first nip former and the second nip former.

18. The image forming apparatus according to claim 17 , wherein the second diameter is sufficiently smaller than the first diameter such that, in at least a direction in which a force is exerted on the ope

Assignees

• Kajiyama Hiroshi
• Ricoh Co Ltd

Inventors

• Kajiyama Hiroshi

Classifications

• G03G15/2064 Primary

  combined with pressure · CPC title

• G03G15/2035

  for maintenance purposes, e.g. for removing a jammed sheet · CPC title

• G03G15/2032

  Retractable heating or pressure unit · CPC title