Unit chair

Patent metadata

Field	Value
Publication number	US-12226027-B2
Application number	US-202017761266-A
Country	US
Kind code	B2
Filing date	Sep 11, 2020
Priority date	Sep 17, 2019
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

The present disclosure relates to a unit chair. The unit chair includes a link unit for adjusting a posture of a headrest, wherein the link unit includes: a first link member fixed to a backrest portion of the unit chair; a second link member having one end portion hinged to the first link member by a first hinge pin; and a first ratchet member formed on one surface of at least one of the first link member and the second link member and constraining motion of the second link member so that the second link member is rotatable only in one direction based on a central axis line of the first hinge pin, wherein the first ratchet member includes a first ratchet base portion including a plurality of saw teeth formed on one surface, arranged in a ring shape based on the central axis line of the first hinge pin, uplifted in a direction toward the central axis line, and inclined only in one direction, and having an opposite surface fixed to the first link member; and a first ratchet rotating portion including a plurality of saw teeth formed on one surface and at least partially engaged with at least some of the saw teeth of the first ratchet base portion and having an opposite surface fixed to the second link member.

First claim

The invention claimed is:

1. A unit chair comprising a link unit for adjusting a posture of a headrest, wherein the link unit includes:
a first link member fixed to a backrest portion of the unit chair;
a second link member having one end portion hinged to the first link member by a first hinge pin; and
a first ratchet member formed on one surface of at least one of the first link member and the second link member and constraining motion of the second link member so that the second link member is rotatable only in one direction about a central axis line of the first hinge pin,
wherein the first ratchet member includes
a first ratchet base portion including a plurality of saw teeth formed on one surface, the plurality of saw teeth arranged in a ring shape centered on the central axis line of the first hinge pin, protruding in a direction parallel to the central axis line, and inclined only in one rotational direction, and the ratchet base portion having an opposite surface fixed to the first link member; and
a first ratchet rotating portion including a plurality of saw teeth formed on one surface and at least partially engaged with at least some of the saw teeth of the first ratchet base portion and having an opposite surface fixed to the second link member, wherein
the second link member includes a first release portion transmitting an external force to the first ratchet member to release the motion constraint state of the second link member, and
wherein the first release portion includes:
a first button protruding from an external side surface of the second link member and receiving an external force applied thereto; and
a first operating member formed inside the second link member and supported by a first elastic member, having one surface to which the first button and the first ratchet rotating portion are fixed, and integrally moving together with the first button and the first ratchet rotating portion to separate the first ratchet rotating portion from the first ratchet base portion when an external force is applied to the first button.

2. The unit chair of claim 1 , further comprising:
a third link member having one end portion hinged to the other end portion of the second link member by a second hinge pin and allowing the headrest to be fixed to one surface thereof; and
a second ratchet member formed on one surface of at least one of the second link member and the third link member and constraining motion of the third link member so that the third link member is rotatable only in one direction about a central axis line of the second hinge pin.

3. The unit chair of claim 2 , wherein
the second link member includes:
a first release portion transmitting an external force to the first ratchet member to release the motion constraint state of the second link member; and
a second release portion operating independently from the first release portion and transmitting an external force to the second ratchet member to release a motion constraint state of the third link member.

4. The unit chair of claim 1 , wherein
the second link member includes a first release portion transmitting an external force to the first ratchet member to release the motion constraint state of the second link member,
wherein the first ratchet member constrains motion of the second link member so that the second link member is rotatable only in one direction about the central axis line of the first hinge pin as the saw teeth of the first ratchet base portion are engaged with the saw teeth of the first ratchet rotating portion, and
the first release portion releases the motion constraint state of the second link member by releasing the engagement of the first ratchet member when an external force is applied.

5. The unit chair of claim 3 , wherein
the second ratchet member includes:
a second ratchet base portion including a plurality of saw teeth formed on one surface, arranged in a ring shape centered on a central axis line of the second hinge pin, protruding in a direction of the central axis line, and inclined only in one direction, and having an opposite surface fixed to the third link member; and
a second ratchet rotating portion including a plurality of saw teeth formed on one surface and at least partially engaged with at least some of the saw teeth of the second ratchet base portion and having an opposite surface fixed to the second link member.

6. The unit chair of claim 1 , wherein
each saw tooth of each of the first ratchet base portion and the first ratchet rotating portion is at an inclination angle of 40 degrees to 50 degrees only in one direction with respect to a surface on which each saw tooth is formed.

7. The unit chair of claim 6 , wherein
the inclination angle is 45 degrees.

8. The unit chair of claim 6 , wherein
any one of the number of saw teeth of the first ratchet base portion and the number of saw teeth of the first ratchet rotating portion is a multiple of 2 or greater of the other.

9. The unit chair of claim 8 , wherein
the number of saw teeth of the first ratchet rotating portion is twice the number of saw teeth of the first ratchet base portion.

10. The unit chair of claim 9 , wherein
the saw teeth of the first ratchet rotating portion are arranged in a ring shape at equiangular intervals.

11. The unit chair of claim 2 , wherein
the second link member is constrained in motion by the first ratchet member and is rotatable only in a direction toward a seat surface of the backrest portion, and
the third link member is constrained in motion by the second ratchet member so that the third link member is rotatable only in a direction opposite to a direction in which the second link member is rotatable.

12. The unit chair of claim 5 , wherein
the second release portion includes:
a second button protruding from an external side surface of the second link member and receiving an external force applied thereto; and
a second operating member formed inside the second link member and supported by a second elastic member, having one surface to which the second button and the second ratchet rotating portion are fixed, and integrally moving together with the second button and the second ratchet rotating portion to separate the second ratchet rotating portion from the second ratchet base portion when an external force is applied to the second button.

13. The unit chair of claim 1 , wherein
a surface becoming a front end when the second link member rotates in one direction, in an external surface of the second link member is recessed when observed in a direction of a central axial line of the first hinge pin.

14. The unit chair of claim 13 , wherein,
when the first link member is fixed to the backrest portion, the other end portion of the second link member, rather than the one end portion of the second link member, contacts a seat surface of the backrest portion.

15. A unit chair comprising a link unit for adjusting a posture of a headrest,
wherein the link unit includes:
a first link member fixed to a backrest portion of the unit chair;
a second link member having one end portion hinged to the first link member by a first hinge pin;
a third link member having one end portion hinged to another end portion of the second link member and allowing the headrest to be fixed to one surface of the third link member;
a first ratchet member formed on one surface of at least one of the first link member and the second link member, constraining motion of the second link member so that the second link member is rotatable only in one direction about a central axis line of the first hinge pin a

Assignees

• Osstem Implant Co Ltd

Inventors

• Park Sang Yong

Classifications

• A61G15/125 Primary

  Head-rests · CPC title

• A61G15/02 Primary

  Chairs with means to adjust position of patient; Controls therefor · CPC title

• A47C1/00

  Chairs adapted for special purposes (chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs, A61G5/00; operating chairs or dental chairs A61G15/00) · CPC title

• A61G15/14

  Dental work stands; Accessories therefor · CPC title

• A61G2203/70

  with special adaptations, e.g. for safety or comfort · CPC title