Title:
DOOR CLOSER
Document Type and Number:
Japanese Patent JP2022080591
Kind Code:
A
Abstract:
To provide a door closer that can be downsized while retaining the advantages of a cam and a rack and pinion and has a back-check function.SOLUTION: Included are: a second check valve 39, which is installed on a piston or cam follower and divides a second oil chamber into a third oil chamber 40 and a fourth oil chamber 41, and closes when a door undergoes an opening movement and opens when the door undergoes a closing movement; and a back-check flow channel. The backcheck flow channel has: a first flow path 71 which establishes a fluid communication between the third oil chamber 40 and the fourth oil chamber 41 while the door undergoes the opening movement until the start of backcheck operation and is blocked during backcheck operation; and a second flow path 72 which has a flow rate lower than the first flow path 71 and establishes the fluid communication between the third oil chamber 40 and the fourth oil chamber 41 during backcheck operation.SELECTED DRAWING: Figure 7
Inventors:
ISHIDA KOJI
TAKAHASHI SHOJI
TAKAHASHI SHOJI
Application Number:
JP2020191738A
Publication Date:
May 30, 2022
Filing Date:
November 18, 2020
Export Citation:
Assignee:
RYOBI LTD
International Classes:
E05F3/10
Attorney, Agent or Firm:
Tokuya Iwata