Chair with seatback and rotating damper device

• US 6,705,677 B2
• Filed: 10/16/2001
• Issued: 03/16/2004
• Est. Priority Date: 02/18/2000
• Status: Expired due to Fees

• Current Assignee: Sugatsune Kogyo Co., Ltd.
• Original Assignee: Sugatsune Kogyo Co., Ltd.
• Inventors: Oshima, Kazuyoshi, Masuda, Hiroyuki
• Primary Examiner(s): Cuomo, Peter M.
• Assistant Examiner(s): EDELL, JOSEPH F
• Application Number:
  US09/959,066
• Publication Number:
  US 20020158495A1
• Time in Patent Office: 882 Days
• Field of Search: 297/300.2, 297/300.4, 297/300.5, 297/337, 297/342, 297/322, 297/316
• US Class Current: 297/300.2
• CPC Class Codes: A47C 1/03238 by means of peg-and-notch or pawl-and-ratchet mechanism
• CPC Class Codes: A47C 1/03255 with a central column, e.g. rocking office chairs
• CPC Class Codes: A47C 1/03266 with adjustable elasticity
• CPC Class Codes: A47C 1/03272 with coil springs
• CPC Class Codes: A47C 1/03274 of torsion type
• CPC Class Codes: A47C 1/03294 slidingly movable in the base frame, e.g. by rollers
• CPC Class Codes: F16F 9/145 involving only rotary movement of the effective parts wing closers or openers with fluid brakes of the rotary type E05F3/14

Abstract

A forward end part of an arm part (53) of a seatback frame is connected to a forward end part of a main frame (3) such that the forward end part of said arm part (53) can turn about a horizontal axis (61) extending leftward and rightward. A cam hole (71) is formed in a forward end part of the arm part (53). A shaft part (72) movably engageable with the cam hole (71) through a roller (73) is disposed at a forward end part of a seat frame (41). The cam hole (71), the shaft part (72) and the roller (73) constitute a positive motion mechanism (70) for causing a seat frame (41) to be tilted in accordance with the turning motion of the arm part (53).

Claims

1. A chair with a seatback comprising a main frame (3), a seat frame (41) arranged at an upper side of said main frame (3), a seatback frame (51) whose forward end part is connected by a connecting portion (61) to a forward end part of said main frame (3) such that the forward end part can turn about a horizontal axis, thereby enabling a rear end part of said seatback frame (51) to be tilted between a working position and a relaxing position, a displacement mechanism disposed between the rear end part of said seat frame (41) and said seatback frame (51) and adapted to displace the rear end part of said seat frame (41) in an obliquely forward/backward direction in accordance with the turning motion of said seatback frame (51), and a positive motion cam mechanism (70) for displacing said seat frame (41) upward and downward, forward and backward and for tilting said seat frame (41) upward and downward in cooperation with said displacement mechanism,

wherein said positive motion cam mechanism (70) is disposed between the forward end part of said seat frame (41) and the forward end part of said seatback frame (51), and

said positive motion cam mechanism (70) is arranged at a rear of the connecting portion (61) at which the seatback frame (51) is turnably connected to the main frame (3).

2. A chair with a seatback according to claim 1, wherein said positive motion cam mechanism (70) includes a cam hole (71) and a shaft (72) movably inserted in said cam hole (71) in a longitudinal direction of said cam hole (71), one of said cam hole (71) and said shaft (72) is disposed at said seat frame (41) and the other is disposed at said seatback frame (51).

3. A chair with a seatback according to claim 2, wherein said cam hole (71) is disposed at said seatback frame (51).

4. A chair with a seatback according to claim 1, wherein a tower end part of a shielding member (92) is disposed at a forward end part of said main frame (3) such that said shielding member (92) can turn about a horizontal axis, said shielding member is adapted to shield a gap formed between a forward end part of said main frame (3) and said seat frame (41) or a seat cushion (42) disposed at said seat frame (41), and an upper part of said shielding plate (92) is connected to a forward end part of said seat frame (41) such that when said gap varies in size in accordance with the displacement of said seat frame (41), said shielding plate (92) is turned in accordance with the size of the gap.

5. A chair with a seatback, comprising a main frame (3), a seat frame (41) arranged at an upper side of said main frame (3), a seatback frame (51) whose forward end part is connected to a forward end part of said main frame (3) such that the forward end part can turn about a horizontal axis, thereby enabling a rear end part of said seatback frame (51) to be tilted between a working position and a relaxing position, a displacement mechanism disposed between the rear end part of said seat frame (41) and said seatback frame (51) and adapted to displace the rear end part of said seat frame (41) in an obliquely forward/backward direction in accordance with the turning motion of said seatback frame (51), and a positive motion cam mechanism (70) for displacing said seat frame (41) upward and downward, forward and backward and for tilting said seat frame (41) upward and downward in cooperation with said displacement mechanism,

wherein said positive motion cam mechanism (70) is disposed between the forward end part of said seat frame (41) and the forward end part of said seatback frame (51), and

wherein said displacement mechanism includes a link (63) connected at a lower end part thereof to said main frame (3) such that said link (63) can turn about a horizontal axis and at an upper end part thereof to a rear end part of said seat frame (41) such that said link (63) can turn about a horizontal axis, a second positive motion cam mechanism (65) disposed between an upper end part of said link (63) and said seatback frame (51) and adapted to cause said link (63) to turn in accordance with the turning motion of said seatback frame (51), and said second positive motion cam mechanism (65) includes a second cam hole (66) and a second shaft (67), said second cam hole (66) being disposed at one of an upper end part of said seatback frame (51) and said link (63), said second shaft (67) being disposed at the remaining one of the upper end part of said seatback frame (51) and said link (63) and movably inserted in said second cam hole (66).

6. A chair with a seatback according to claim 5, wherein said main frame (3) is provided with an engagement member (90) removably engaged with said link (63) and adapted to positionally fix said seatback frame (51) to the working position by prohibiting the turning of said link (63) at the time of engagement.

7. A chair with a seatback comprising a main frame (120), a seat (149) supported by said main frame (120), and a seatback (150) arranged at a location higher than a rear part of said seat (140) and supported by said main frame (120) through a support arm (162),

wherein a pair of said support arms (162) are disposed one at a left and the other at a right, and said pair of support arms (162, 162) are elastically deformable so that when a user twisted his body with his back pressed against said seatback (150), said seatback (150) can turn in a horizontal direction following the twisting motion of the user'"'"'s body, and

wherein said seat (140) is tiltably supported by said main frame (120) for tilting between a working position and a relaxing position through a tilting mechanism (130), a pair of return springs (160, 160) are disposed between said main frame (120) and said seat (140) and adapted to bias said seat (140) from the relaxing position side to the working position side, and end parts of said pair of return springs (160, 160) for biasing said seat (140) from the relaxing position side to the working position side serve also as said support arms (162, 162).

8. A chair with a seatback according to claim 7, wherein said tilting mechanism (130) includes two pairs of front and rear turning links (133, 133;

131, 131) whose lower end parts are supported by said main frame (120) such that the lower end parts can turn about a horizontal axis extending leftward and rightward and whose upper end parts are connected to said seat (140) such that the upper end parts can turn about a horizontal axis extending leftward and rightward, a coiled spring is used as said return spring (160), and a pair of said coiled springs (160, 160) are arranged in a row between said pair of front turning links (133, 133).

9. A chair with a seatback according to claim 8, wherein said main frame (120) is provided with a rotary damper (180) for restricting a high speed turning of at least one of said two pairs of turning links (133, 133;

131, 131).

10. A chair with a seatback according to claim 8, wherein said main frame (120) is provided with an adjusting mechanism (170) for adjusting biasing force of said coiled springs (160, 160) in accordance with turning operation of said adjustment member (175), and an adjustment member (175) for operating said adjustment mechanism (170) is disposed at a front end part of said main frame (120) and at a front part of a generally central area of said pair of front turning links (133, 133).