Drive transmission device and image forming apparatus including the same

Patent metadata

Field	Value
Publication number	US-10824109-B2
Application number	US-201916388676-A
Country	US
Kind code	B2
Filing date	Apr 18, 2019
Priority date	Jan 9, 2015
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

An elastic force of an elastic member 11 required for rotating a driven rotational body 8 b is decreased.
A first rotational body 8 d and a second rotational body 9 a arranged downstream of a driven rotational body 8 b in a drive train that transmits a driving force from a driving rotational body 7 to a driven member 4 are included. The first rotational body 8 d rotates in synchronization with the driven rotational body 8 b . The second rotational body 9 a is rotated by the first rotational body 8 d and rotates the driven member 4 . The first rotational body 8 d rotates without rotating the second rotational body 9 a when the driven rotational body 8 b rotates by an elastic force of an elastic member 11.

First claim

The invention claimed is:

1. A drive transmission device including a driving rotational body, a driven rotational body that rotates by engaging with the driving rotational body, a driven member that is driven by the rotation of the driven rotational body, and an elastic member that rotates the driven rotational body by an elastic force when the driven rotational body does not engage with the driving rotational body, the drive transmission device comprising:
a first rotational body and a second rotational body arranged downstream of the driven rotational body in a drive train that transmits a driving force from the driving rotational body to the driven member, the first rotational body being configured to rotate in synchronization with the driven rotational body, the second rotational body being configured to be rotated by the first rotational body and drive the driven member,
wherein, when the driven rotational body rotates by the elastic force of the elastic member, a case in which the first rotational body rotates without rotating the second rotational body, and a case in which the first rotational body rotates while rotating the second rotational body are provided,
wherein the driven member can move to a first position and a second position as a result that the driven member is driven by the second rotational body, and a load required for the driven member to move when the driven member is positioned at the first position is larger than a load required for the driven member to move when the driven member is positioned at the second position, and
wherein the first rotational body rotates without rotating the second rotational body by the elastic force of the elastic member when the driven member is positioned at the first position, and the first rotational body rotates while rotating the second rotational body by the elastic force of the elastic member when the driven member is positioned at the second position.

2. The drive transmission device according to claim 1 ,
wherein the first rotational body rotates the second rotational body so that the driven member is displaced from the first position to the second position by a rotational force of the driving rotational body via the driven rotational body.

3. The drive transmission device according to claim 2 ,
wherein the first rotational body rotates the second rotational body so that the driven member is displaced from the second position to the first position by a rotational force of the driving rotational body via the driven rotational body.

4. The drive transmission device according to claim 3 ,
wherein the first rotational body and the second rotational body are gears that mesh with each other,
wherein a gear portion is not formed in a portion of the first rotational body that faces the second rotational body in a phase in which the driven member is positioned at the first position, and
wherein the first rotational body and the second rotational body are meshed with each other in a phase in which the driven member is positioned at the second position.

5. The drive transmission device according to claim 4 ,
wherein an arcuate surface coaxial with a rotation center of the first rotational body is provided in a portion of the first rotational body that faces the second rotational body in a phase in which the driven member is positioned at the first position, and an arcuate surface extending along the arcuate surface of the first rotational body is provided in a portion of the second rotational body that faces the first rotational body in the phase in which the driven member is positioned at the first position.

6. The drive transmission device according to claim 5 ,
wherein the arcuate surface of the second rotational body includes a plurality of arcuate surfaces.

7. The drive transmission device according to claim 3 ,
wherein the first rotational body and the second rotational body are gears that mesh with each other,
wherein a gear portion is not formed in a portion of the second rotational body that faces the first rotational body in a phase in which the driven member is positioned at the first position, and
wherein the first rotational body and the second rotational body are meshed with each other in a phase in which the driven member is positioned at the second position.

8. The drive transmission device according to claim 1 ,
wherein the driving rotational body and the driven rotational body are gears that mesh and engage with each other, and the driven rotational body has a portion that does not have a gear portion and does not mesh with the driving rotational body.

9. The drive transmission device according to claim 1 ,
wherein the driven rotational body is rotated to a position, at which the engagement between the driven rotational body and the driving rotational body is completely released, by the elastic force of the elastic member.

10. The drive transmission device according to claim 1 , further comprising:
another driven rotational body that rotates coaxially with the driven rotational body by engaging with the driving rotational body; and
another elastic member provided between the driven rotational body and the another driven rotational body,
wherein the driven rotational body is rotated to a position, at which the engagement between the driven rotational body and the driving rotational body is completely released, by the elastic force of the elastic member against an urging force of the another elastic member.

11. An image forming apparatus for forming a toner image on a recording material, comprising:
the transmission device according to claim 1 ;
an image bearing body;
a developing member that causes a toner to adhere to the image bearing body; and
a drive source that rotates the developing member,
wherein a driving force from the drive source is not transmitted to the developing member when the driven member of the drive transmission device is positioned at the first position, and the driving force from the drive source is transmitted to the developing member and the developing member rotates when the driven member of the drive transmission device is positioned at the second position.

12. A drive transmission device comprising:
a first clutch section for transmitting and interrupting a driving force;
a second clutch section for changing the first clutch section to a drive transmitting state and a drive interrupting state, the second clutch section including a driving rotational body, a driven rotational body that rotates by engaging with the driving rotational body, an elastic member that rotates the driven rotational body by an elastic force when the driven rotational body does not engage with the driving rotational body, a first rotational body and a second rotational body arranged downstream of the driven rotational body in a drive train that transmits the driving force from the driving rotational body to the first clutch section,
wherein the first rotational body is configured to rotate in synchronization with the driven rotational body, the second rotational body is configured to be rotated by the first rotational body and drive the first clutch section,
wherein, when the driven rotational body rotates by the elastic force of the elastic member, a case in which the first rotational body rotates without rotating the second rotational body, and a case in which the first rotational body rotates while rotating the second rotational body are provided,
wherein the first clutch section can move to a first position and a second position as a result that the first clutch section is driven by the second rotational body, and a load required for the first clutch section to move wh

Assignees

• Canon Kk

Inventors

• Chino Hideto
• Ochi Junichi

Classifications

• G03G2215/0177

  Rotating set of developing units · CPC title

• F16H1/20

  involving more than two intermeshing members · CPC title

• G03G21/1647 Primary

  Mechanical connection means · CPC title