JP-7854702-B2 - chair

Inventors

• 長坂 典明
• 長谷田 未弦

Assignees

• 株式会社クオリ

Dates

Publication Date

20260507

Application Date

20220317

Claims (1)

1. A chair comprising legs, a seat positioned above the legs, a support base located between the legs and the seat for supporting the seat on the legs, a backrest support connected to the support base for supporting the backrest, and a seat lifting mechanism that causes the seat to move up and down in accordance with the tilt of the backrest, The support base comprises a support base fixed above the leg portion and a seat support fixed below the seat portion. The seat lifting mechanism comprises: a movable arm extending forward from the lower end of the backrest support and positioned within the support base; a fixed shaft provided near the rear end of the support base that pivotally supports the movable arm so as to be able to tilt in sync with the tilting of the backrest support; a movable shaft located in front of the fixed shaft in the support base that pivotally supports the seat so as to be able to move up and down in accordance with the tilting of the movable arm; a vertically elongated lifting slot formed in the support base for moving the movable shaft up and down; a horizontally elongated first sliding slot formed in the seat for sliding the fixed shaft in the front-rear direction; a horizontally elongated second sliding slot formed in the seat so as to intersect with the lifting slot for sliding the movable shaft in the front-rear direction; and a lifting means provided in front of the movable shaft in the support base that moves the front end of the seat above the top where the movable shaft moves. The chair is characterized in that the lifting mechanism is a link member pivotally supported by the support base and the seat support, and the inside of the link member is formed to be slidable on the arc-shaped front upper end of the support base .

Description

This invention relates to a chair equipped with a seat height adjustment mechanism that causes the seat to move up and down in accordance with the tilt of the backrest. In chairs equipped with a rocking function, where the backrest tilts backward when the sitter leans back, there exists a further development called a weight-sensing chair. This type of chair uses the sitter's weight to raise and lower the seat when they lean back. Because the seat of such a weight-sensing chair moves in accordance with the backrest's tilt, it provides a more consistent backrest tilting sensation compared to typical rocking chairs where the backrest only tilts backward, regardless of the sitter's body weight. Furthermore, a common example of a weight-sensing rocking chair is the one shown in Patent Document 1. In this chair, the lower end of the reinforcing member 12 of the backrest support rod 9 is pivotally attached to the base 6 by a first pivot 8, and the upper end of the reinforcing member 12 of the backrest support rod 9 is pivotally attached to the rear of the seat support member 31 by a fourth pivot 33. When the backrest is tilted backward, the seat support member 31 rotates upward and rearward around the first pivot 8, and consequently, the seat 7 supported by the seat support member 31 also moves upward and rearward. Japanese Patent Publication No. 2013-153868 In the weight-sensing chair described in Patent Document 1, it is necessary to rotate the reinforcing member 12 of the backrest support 9 in order to raise or lower the seat support 31. This necessitates securing space within the base 6 to move the reinforcing member 12 in an arc shape with at least the first pivot 8 and the fourth pivot 33 as radii, inevitably resulting in various design constraints, including those on the base 6. Furthermore, if the seat support 31 is raised or lowered solely by the rotation of the reinforcing member 2, the position of the seat 7 can only be adjusted within the rotational range of the reinforcing member 2, thus limiting the ability to maintain a more appropriate seating posture for the sitter when the backrest is tilted backward. Side view of a chair with the seated person not tilting the backrest backward.A side view showing a chair with the seated person tilted backward.Exploded perspective view of the support base.Plan view of the support base.Side view and longitudinal section of the support base.A side view and a side vertical cross-sectional view showing the operation of the seat lifting mechanism of the support base.A side view of the support base showing another embodiment of the lifting mechanism for moving the front end of the seat support upward.A side view and a side vertical cross-sectional view of the support base illustrating the mechanism for locking the tilt angle of the backrest. The following describes embodiments of the chair according to the present invention based on the drawings. Figure 1 is a side view of the chair when the seated person has not tilted the backrest backward, Figure 2 is a side view of the chair when the seated person has tilted the backrest backward, Figure 3 is an exploded perspective view of the support base, Figure 4 is a plan view of the support base, Figure 5 is a longitudinal cross-sectional side view of the support base, and Figure 6 is a side view and a longitudinal cross-sectional side view showing the operation of the seat lifting mechanism of the support base. The chair of this embodiment is generally composed of a leg portion 1, a seat portion 2 positioned above the leg portion 1, a support base portion 3 located between the leg portion 1 and the seat portion 2 for supporting the seat portion 2 on the leg portion 1, a backrest support portion 5 connected to the support base portion 3 and supporting the backrest 4, and a seat lifting mechanism that causes the seat portion 2 to move up and down in accordance with the tilting of the backrest 5. Furthermore, the aforementioned support base 3 further comprises a support base 6 fixed to the upper part of the leg portion 1 and a seat support 7 fixed to the lower part of the seat portion 2. A movable arm 8 is formed at the lower end of the backrest support portion 5, extending forward and positioned within the support base 3. By combining these components—the support base 6 and seat support 7 of the support base 3, and the movable arm 8 at the lower end of the backrest support portion 5—a seat lifting mechanism is formed that allows the seat portion 2 to move up and down in accordance with the tilt of the backrest 5. Moreover, the seat lifting mechanism of the chair in this embodiment is configured to allow not only vertical movement of the seat portion 2 but also lateral movement. Furthermore, the chair described in this embodiment includes a link member 9 as a lifting means for moving the front end of the seat support 7 up and down. In this description, "rear" refers to the backrest 4 side of the chair, "front" refers to the opp