Open and close device, sheet conveyor, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-12459767-B2
Application number	US-202318492060-A
Country	US
Kind code	B2
Filing date	Oct 23, 2023
Priority date	Nov 11, 2022
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

An open and close device, a sheet conveyor, and an image forming apparatus. The open and close device includes an open and close portion to open or shut, a biasing mechanism to bias the open and close portion in an opening direction, and a holder to hold the open and close portion shut. The biasing mechanism includes a first spring whose biasing force is invariable regardless of a stroke of the first spring, and a second spring whose biasing force is variable due to a stroke of the second spring. The sheet conveyor includes the open and close device, and the open and close portion includes a conveyor to convey a sheet. The image forming apparatus includes the sheet conveyor.

First claim

What is claimed is:

1 . An open and close device comprising:
an open and close portion to open or shut; a biasing mechanism to bias the open and close portion in an opening direction; and a holder to hold the open and close portion shut, the biasing mechanism including a first spring whose biasing force is invariable regardless of a stroke of the first spring, and a second spring whose biasing force is variable due to a stroke of the second spring.

2 . The open and close device according to claim 1 ,
wherein the first spring is a retractable spring.

3 . The open and close device according to claim 2 ,
wherein the biasing mechanism further comprises: a slider disposed between the first spring and the open and close portion, the slider to slide in response to a change in the stroke of the first spring; and a linear member disposed between the first spring and the open and close portion, the linear member to hoist the open and close portion, and wherein the first spring has a rotation center on a same side as a winding portion of the first spring with respect to an extended plane obtained by extending a coupling surface on which the linear member is coupled to the slider.

4 . The open and close device according to claim 2 ,
wherein the biasing mechanism further comprises:
a slider disposed between the first spring and the open and close portion, the slider to slide in response to a change in the stroke of the first spring;
a linear member disposed between the first spring and the open and close portion, the linear member to hoist the open and close portion; and
an abutment part disposed between the first spring and the open and close portion, the abutment part to contact the linear member to change a direction of extension of the linear member,
wherein the first spring has a rotation center on a same side as a winding portion of the first spring with respect to an extended line obtained by extending a portion of the linear member between the slider and the abutment part on a plane perpendicular to a direction of a rotation axis of the first spring.

5 . The open and close device according to claim 1 ,
wherein the biasing mechanism further comprises a linear member to hoist the open and close portion.

6 . The open and close device according to claim 5 , further comprising
an abutment part to contact the linear member to change a direction of extension of the linear member.

7 . The open and close device according to claim 1 ,
wherein the biasing mechanism further comprises:
a slider disposed between the first spring and the open and close portion, the slider to slide in response to a change in the stroke of the first spring; and
a guide disposed between the first spring and the open and close portion, the guide to guide the slider in a direction of the stroke of the first spring or in a direction of the stroke of the second spring.

8 . The open and close device according to claim 7 ,
wherein the biasing mechanism further includes a bearing, and wherein the guide is to guide the slider through the bearing.

9 . A sheet conveyor comprising
an open and close device including:
an open and close portion to open or shut;
a biasing mechanism to bias the open and close portion in an opening direction; and
a holder to hold the open and close portion shut,
the biasing mechanism including a first spring whose biasing force is invariable regardless of a stroke of the first spring, and a second spring whose biasing force is variable due to a stroke of the second spring, the open and close portion including a conveyor to convey a sheet.

10 . An image forming apparatus comprising
a sheet conveyor comprising
an open and close device including:
an open and close portion to open or shut;
a biasing mechanism to bias the open and close portion in an opening direction; and
a holder to hold the open and close portion shut,

the biasing mechanism including a first spring whose biasing force is invariable regardless of a stroke of the first spring, and a second spring whose biasing force is variable due to a stroke of the second spring, the open and close portion including a conveyor to convey a sheet.

Assignees

• Ishihara Hiroki
• Nozawa Kenji
• Nakamura Takehiro
• Ricoh Co Ltd

Inventors

• Ishihara Hiroki
• Nozawa Kenji
• Nakamura Takehiro

Classifications

• B65H2402/54

  Springs, e.g. helical or leaf springs · CPC title

• B65H2402/441

  movable for facilitating access to area inside the housing, e.g. pivoting or sliding · CPC title

• B41J11/0015

  for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing (selective coating B41J2/2114) · CPC title

• B41J11/007

  Conveyor belts or like feeding devices · CPC title

• B41J29/13

  Cases or covers · CPC title