JP7638513B2 - Seat lifting device - Google Patents

Description

This disclosure relates to a seat lift-up device.

Theaters, halls, and other venues often have chairs with seats that can rotate from a standing position when not seated to a sitting position when seated. A technology is known for such chairs that allows the seat to stand up by automatically rotating from the sitting position to a standing position when the seated person leaves the seat.

Patent Document 1 discloses a chair seat raising device that includes a seat support shaft, a spring hook member, and a coil spring. One end of the coil spring is hooked to a seat frame whose left and right portions are rotatably supported by the seat support shaft so that the chair seat can rotate between a seated position and an upright position. The other end of the coil spring is hooked to a spring hook member that positions the spring at a predetermined circumferential position relative to the seat support shaft that passes through the interior. In this chair seat raising device, the spring hook hole to which the other end of the coil spring is hooked is changed to one of multiple spring hook holes provided in the circumferential direction of the spring hook member, thereby appropriately changing the elastic force of the coil spring and adjusting the speed at which the seat rises.

Japanese Patent Application Publication No. 11-290155

However, in the above-mentioned chair seat raising device, the position of the spring hook hole in the spring hook member is fixed, which makes it difficult to make fine adjustments that take into account variations in elastic force due to individual differences in the coil springs.

One aspect of the present disclosure aims to provide a new technology that makes it easy to adjust the speed at which the seat of a chair rotates from a seated position to a standing position.

One aspect of the present disclosure is a seat lift-up device for a chair in which a seat on which a user can sit is configured to be rotatable around a predetermined rotation axis from a seated position when seated to an upright position when not seated, and which includes a torsion spring, a rotating member, and an adjustment member. The torsion spring has a first end fixed to a seat frame of the seat. The rotating member has a second end fixed opposite the first end of the torsion spring, and rotates together with the second end in the torsional direction of the torsion spring. The adjustment member is held by a holding member that does not rotate together with the seat, and adjusts the position of the rotating member. The seat rotates from the seated position to the upright position due to the elastic force caused by the torsional deformation of the torsion spring. The position of the second end in the torsional direction changes as the position of the rotating member is adjusted by the adjustment member.

In this configuration, with the first end of the torsion spring fixed to the seat frame, the position of the rotating member is adjusted by the adjustment member, so that the second end of the torsion spring rotates together with the rotating member in the torsional direction of the torsion spring, changing the position of the second end in the torsional direction. Therefore, by adjusting the position of the rotating member with the adjustment member, it is possible to strengthen or weaken the elastic force caused by the torsional deformation of the torsion spring. Therefore, the speed at which the seat of the chair rotates from a seated position to a standing position can be easily adjusted using the adjustment member.

In one aspect of the present disclosure, the rotating member may have an abutment surface against which the adjustment member abuts. The rotating member may also rotate in the torsional direction together with the second end by moving the position of the abutment surface in response to the displacement of the adjustment member. With this configuration, the position of the rotating member in the torsional direction can be easily adjusted by displacing the adjustment member to move the position of the abutment surface.

In one aspect of the present disclosure, the adjustment member may have an apex that abuts against the abutment surface. The abutment surface may have a curved shape such that at least a portion of the abutment surface perpendicularly abuts against the apex when the rotating member rotates in the torsional direction. With this configuration, the force caused by the displacement of the adjustment member is more likely to be applied to the abutment surface. If the abutment surface is flat, when the rotating member rotates in the torsional direction of the torsion spring by the adjustment member, the abutment surface is more likely to intersect with the apex at an angle, and the abutment surface and the apex are less likely to abut perpendicularly. On the other hand, when the abutment surface has a curved shape as in one aspect of the present disclosure, the abutment surface and the apex are more likely to abut perpendicularly, and the force caused by the displacement of the adjustment member is more likely to be applied to the abutment surface compared to when the abutment surface is flat.

In one aspect of the present disclosure, the rotating member may be held by a holding member. The holding member may have an attachment portion to which the adjustment member is attached, and a rotation surface to which the rotating member is rotatably attached. With this configuration, the adjustment member and the rotating member are held by the holding member, so that the rotating member and the adjusting member can be easily positioned in the seat lift-up device.

In one aspect of the present disclosure, the seat frame may further include a rotation support portion. The rotation support portion rotatably supports the seat frame and does not rotate with the seat. The retaining member may be cylindrical and the rotation support portion may pass through it. The rotation surface may be the outer peripheral surface of the retaining member. The rotating member may be cylindrical and the retaining member may pass through it so as to surround the rotation surface from the outside. With this configuration, the seat lift-up device can be configured with a simple configuration by using the rotation support portion, without the need for other parts to fix the retaining member so that it does not rotate with the seat.

In one aspect of the present disclosure, the rotating member may have a mark that indicates a guide for adjusting the strength of the elastic force by the adjustment member. With this configuration, the strength of the elastic force caused by the torsional deformation of the torsion spring can be easily adjusted based on the guide mark. In addition, the strength of the elastic force caused by the torsional deformation of the torsion spring can be visually confirmed.

FIG. FIG. 2 is a front view of the seat in an upright position. FIG. FIG. 2 is a schematic diagram showing an enlarged right side view of the seat lift-up device. FIG. 2 is a perspective view of the holding member as viewed from the front left side. FIG. FIG. FIG. FIG. 2 is a perspective view of a rotating member as viewed from the front left side. FIG. FIG. FIG. 13 is a schematic diagram showing the movement of the seat flip-up device as viewed from the right side when the elastic force caused by the torsional deformation of the torsion spring is strengthened. FIG. 14 is a perspective view showing a schematic arrangement of a rotating member, a holding member, and an adjusting member in FIG. 13. FIG. 13 is a schematic diagram showing the movement of the seat flip-up device as viewed from the right side when the elastic force caused by the torsional deformation of the torsion spring is weakened. FIG. 16 is a perspective view showing a schematic arrangement of a rotating member, a holding member, and an adjusting member in FIG. 15 .

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.
[1. Configuration]
[1-1. Seat]
The seat 100 shown in FIG. 1 and FIG. 2 is a part of the chair configured so that a user can sit on it. When the user is not using the chair, that is, when not seated, the seat 100 is in an upright position in which the backrest 200, which is configured to support the back of the seated user, and the seating surface 101 of the seat 100 are arranged approximately parallel to each other. When the user is using the chair, that is, when seated, the seat 100 is in a seated position in which the seating surface 101 of the seat 100 is approximately perpendicular to the backrest 200. That is, the seat 100 is configured to be rotatable between the upright position and the seated position around the rotation axis A. In the following description, for convenience of explanation, the up-down direction and the front-back direction are expressed based on the state in which the seat 100 is in the upright position. Furthermore, the left-right direction is expressed based on the user normally seated on the chair when the seat 100 is in the seated position.

The seat 100 comprises a seat frame 11, a seat plate 12, a cushion portion 13, and a seat lift-up device 300 having a rotation support portion 14.
The seat frame 11 is a rectangular frame, and is formed by an upper plate 111 disposed above, a lower plate 112 disposed below, a left plate 113 disposed on the left side, and a right plate 114 disposed on the right side. When the seat 100 is in the seated position, the upper plate 111 is disposed forward, and the lower plate 112 is disposed rearward.

The seat plate 12 is a generally rectangular resin plate that covers the rear surface of the seat frame 11. The seat plate 12 may have a number of grooves drilled in an arc shape symmetrically to form a number of concentric circles.

The cushion portion 13 is a cushioning material that is placed so as to cover at least the rear surface of the seat plate 12 and the upper plate 111 of the seat frame 11, and constitutes the seating surface 101 of the seat portion 100. That is, when the seat portion 100 is in the seating position, the seat plate 12 and the cushion portion 13 are placed in that order on the upper surface of the seat frame 11. The seat portion 100 may be covered with fabric or the like from above the cushion portion 13. The seat portion 100 may also have a plate-shaped back cover that covers the front surface of the seat frame 11 so as to close it. That is, when the seat portion 100 is in the seating position, the back cover may be placed on the underside of the seat frame 11.
The seat lift-up device 300 is provided near the lower right side within the internal space formed by the seat frame 11 .

The rotation support 14 is a cylindrical pipe having a length, and the cross section perpendicular to the central axis of the rotation support 14 is rectangular. The rotation support 14 is fixed to a support pillar (not shown) erected on both the left and right sides of the seat 100 so as not to rotate with the seat 100. The rotation support 14 is fixed to the above-mentioned support pillar so that the central axis of the rotation support 14 is approximately parallel to the floor surface on which the chair equipped with the seat 100 is placed. The support pillar may be, for example, the leg of the chair equipped with the seat 100, which is provided on both the left and right sides of the seat 100. The rotation support 14 passes through the first through hole 115 shown in FIG. 3, which is provided on the lower side of the left side plate 113 and the right side plate 114 of the seat frame 11, and supports the seat frame 11 so that it can rotate around the rotation support 14. In other words, the central axis of the rotation support 14 coincides with the rotation axis A about which the seat 100 rotates between the standing position and the sitting position. As shown in FIG. 2, in this embodiment, the shafts 141 are attached to both side ends of the rotation support 14 so that the rotation support 14 rotatably supports the seat frame 11. Although detailed illustration is omitted, the shaft 141 has a rectangular hole through which the rotation support 14 passes so as to be fixed to the rotation support 14, and a circular outer peripheral surface that is rotatably inserted into a circular through hole of the seat frame 11. As shown in FIG. 3, a prevention plate 142 that can prevent the shaft 141 from penetrating may be provided on the outside of the seat frame 11 so that the shaft 141 does not completely penetrate the first through hole 115 of the seat frame 11. The prevention plate 142 is formed with a second through hole 143 having a portion with an inner diameter smaller than the outer diameter of the outer peripheral surface of the shaft 141. In the example shown in FIG. 3, the outer peripheral surface of the shaft 141 is inserted into the second through hole 143 of the prevention plate 142, and is inserted into the first through hole 115 of the seat frame 11.

[1-2. Seat lift-up device]
The seat lift-up device 300 shown in Fig. 3 is a device that can automatically rotate the seat 100 from a seated position to a standing position, for example, when a person sitting on the chair leaves the seat. The seat lift-up device 300 includes a torsion spring 3, an adjustment member 4, a holding member 5, a rotating member 6, and a stopper 7. In this embodiment, the shaft 141, the stopper 7, the torsion spring 3, and the rotating member 6 are extrapolated to be aligned in that order from right to left in the portion of the rotation support part 14 that spans the internal space of the seat frame 11, and the holding member 5 is extrapolated to overlap the torsion spring 3 and the rotating member 6.

The stopper 7 is attached to the rotation support part 14 so that it is positioned between the shaft part 141 and the holding member 5 described later. The rotation support part 14 passes through a rectangular hole part of the stopper 7, and the stopper 7 is fixed to the rotation support part 14 so that it cannot rotate. The stopper 7 has a protrusion 71 on the left side of the stopper 7 that is inserted into the cylindrical part of the torsion spring 3 described later.

The torsion spring 3 is a torsion coil spring formed in a coil shape so as to have a cylindrical portion. As shown in FIG. 3 and FIG. 4, the torsion spring 3 has a first end 31 fixed to the seat frame 11, and a second end 32 opposite to the first end 31 fixed to the rotating member 6 described later. Specifically, the first end 31 of the torsion spring 3 is fixed so as to be hooked on a screw 8 fixed to the right side plate 114 of the seat frame 11 so as to penetrate from the outside to the inside. In addition, the second end 32 of the torsion spring 3 is fixed so as to be hooked on a spring hook portion 63 of the rotating member 6. Therefore, when the first end 31 of the torsion spring 3 is twisted in the first torsional direction θ1 shown in FIG. 4 with the second end 32 fixed, the elastic force F accumulated due to the torsional deformation of the torsion spring 3 can be released. The first torsional direction θ1 is the same direction as the direction in which the seat 100 rotates from the standing position to the sitting position. In other words, the elastic force F is a force that acts in the direction in which the seat 100 automatically rotates from the sitting position to the standing position.

The adjustment member 4 is a screw held by the holding member 5 described later. The adjustment member 4 is a hexagonal socket set screw whose position is fixed by a double nut such as a hexagonal nut and a square nut. Specifically, the adjustment member 4 is inserted into the fourth through hole 571 of the mounting portion 57 of the holding member 5 described later, and then the position is fixed by clamping the upper and lower directions with double nuts. The adjustment member 4 may be, for example, a set screw with a knob or screws of various shapes. The fourth through hole 571 into which the adjustment member 4 is inserted may also have a female thread. In this case, fine adjustment of the vertical position of the adjustment member 4 is made easier. Even when the adjustment member 4 is inserted into the fourth through hole 571 with a female thread, a nut or the like may be attached to prevent the adjustment member 4 from loosening.

The retaining member 5 holds the adjustment member 4 and the rotating member 6 described below, and is configured to be inserted into a part of the cylindrical portion of the torsion spring 3. The retaining member 5 is a resin member fixed to the rotation support portion 14 so as not to rotate together with the seat portion 100. As shown in Figures 5 to 8, the retaining member 5 is formed in a substantially cylindrical shape. The retaining member 5 has a first groove 53, a positioning portion 54, a protrusion 55, a fixing portion 56, an attachment portion 57, and a rotating surface 58.

The first groove 53 is a groove extending from the first end 51 to the second end 52 of the holding member 5. In this embodiment, the holding member 5 is fixed to the rotation support part 14 so that the first end 51 is disposed on the left and the second end 52 is disposed on the right. Four first grooves 53 are provided on the inner peripheral surface of the holding member 5. The four first grooves 53 are disposed so that the four corners of the rotation support part 14 inserted inside fit into them. By fitting the four corners of the rotation support part 14 into the four first grooves 53, the rotation of the holding member 5 relative to the central axis of the rotation support part 14 is suppressed. In other words, the four first grooves 53 suppress the rotation of the holding member 5 relative to the rotation support part 14 in the first torsional direction θ1 and the second torsional direction θ2 shown in FIG. 4, which is the opposite direction.

The positioning portion 54 is provided near the first end portion 51 of the holding member 5. The positioning portion 54 is a portion that protrudes in an annular shape from the outer circumferential surface of the holding member 5.
The protrusion 55 protrudes from the outer peripheral surface of the holding member 5. The protrusion 55 is provided on the outer peripheral surface of the holding member 5, closer to the second end 52 than the positioning portion 54. Two protrusions 55 are provided on the outer peripheral surface of the holding member 5. The two protrusions 55 are arranged in positions facing each other. In this embodiment, the holding member 5 is fixed to the rotation support portion 14 so that the two protrusions 55 are respectively arranged above and below the holding member 5.

The fixing portion 56 is provided on the outer peripheral surface of the holding member 5, closer to the first end 51 than the positioning portion 54. In this embodiment, the fixing portion 56 is disposed in front of the holding member 5. The fixing portion 56 has a third through hole 561 that penetrates from the outer peripheral surface to the inner peripheral surface of the holding member 5. By inserting the screw 9 shown in FIG. 3 into the third through hole 561 and fixing the holding member 5 to the rotation support portion 14 by the fixing portion 56, movement of the holding member 5 relative to the rotation support portion 14 in the direction along the central axis of the rotation support portion 14 is suppressed.

The mounting portion 57 is provided on the outer peripheral surface of the holding member 5, closer to the second end 52 than the positioning portion 54. In this embodiment, the mounting portion 57 is a portion that protrudes toward the front of the holding member 5. The mounting portion 57 has a U-shape when viewed from the front. The mounting portion 57 has a fourth through hole 571 and a second groove 572. The fourth through hole 571 is a hole that penetrates in the vertical direction through a protruding wall that extends forward and in the left-right direction among the protruding walls of the mounting portion 57. The second groove 572 is a groove that extends upward from the protruding wall in which the fourth through hole 571 is provided, and is provided on the outer peripheral surface of the holding member 5. The above-mentioned adjustment member 4 is attached to the mounting portion 57 by being inserted into the fourth through hole 571. The adjustment member 4 is attached to the mounting portion 57 so that its position can be displaced in the vertical direction along the second groove 572.

The rotation surface 58 is the surface of the outer circumferential surface of the holding member 5 that is closer to the second end 52 than the positioning portion 54. As shown in Figs. 7 and 8, the outer diameter of the holding member 5 decreases from the positioning portion 54 toward the second end 52. In other words, the rotation surface 58 has an inclination that approaches the central axis of the holding member 5 from the first end 51 side toward the second end 52 side. The two convex portions 55 described above are disposed on the rotation surface 58. As shown in Fig. 3, on the rotation surface 58, a part of the cylindrical portion of the torsion spring 3 described above is extrapolated on the second end 52 side of the convex portion 55, and the rotation member 6 described later is rotatably fixed on the first end 51 side of the convex portion 55.

The rotating member 6 is a resin member that can rotate together with the second end 32 of the torsion spring 3 around the first torsional direction θ1 and the second torsional direction θ2 shown in FIG. 4, i.e., the rotation axis A. In the following description, when it is not necessary to specify the rotational directions of the first torsional direction θ1 and the second torsional direction θ2, they are simply referred to as the torsional directions. The rotating member 6 is formed in a substantially cylindrical shape. As shown in FIG. 3, the rotating member 6 is rotatably attached on the rotation surface 58 of the holding member 5. In other words, the holding member 5 penetrates the inside of the rotating member 6 so as to cover the rotation surface 58 from the outside. The first end 61 of the rotating member 6 abuts against the positioning portion 54 of the holding member 5. A notch portion 611 is formed on the first end 61 side of the rotating member 6 so that the first end 61 can abut against the positioning portion 54 so as not to interfere with the mounting portion 57 when the rotating member 6 is attached to the holding member 5. The rotating member 6 is attached to the holding member 5 so that the mounting portion 57 of the holding member 5 is inserted into the notch portion 611 of the rotating member 6.

As shown in FIGS. 9 to 12 , the rotating member 6 has a spring hook portion 63 , a contact portion 64 , a third groove 65 , and a fourth groove 66 .
The spring hook portion 63 is a portion that protrudes so as to be folded back along the cylindrical curve to the outside of the rotating member 6. The spring hook portion 63 has a hook groove 631 and a folded portion 632. The hook groove 631 is a groove that extends from the second end 62 side of the rotating member 6 toward the first end 61 side. The second end 32 of the torsion spring 3 described above is fitted into the hook groove 631 so as to be hooked. The folded portion 632 is a plate-shaped portion that extends along the outer periphery of the rotating member 6 to prevent the torsion spring 3 that fits into the hook groove 631 from coming off the spring hook portion 63.

The abutment portion 64 is a portion that protrudes outward from the cylindrical shape of the rotating member 6. The abutment portion 64 has an abutment surface 641 against which the adjustment member 4 abuts. The abutment surface 641 is the surface of the abutment portion 64 facing the adjustment member 4, and has a curved shape. Specifically, the abutment surface 641 has a curved shape so that a portion of the abutment surface 641 always abuts vertically against the apex portion 41 of the adjustment member 4 when the rotating member 6 rotates in the second torsional direction θ2 shown in FIGS. 13 and 14, or the first torsional direction θ1 shown in FIGS. 15 and 16. The rotating member 6 is attached to the holding member 5 so that the abutment surface 641 of the rotating member 6 is positioned above the mounting portion 57 of the holding member 5.

Returning to FIG. 12 from FIG. 9, the third groove 65 is a groove that extends from the first end 61 to the second end 62 of the rotating member 6. Two third grooves 65 are provided on the inner circumferential surface of the rotating member 6 so as to face each other.

The fourth groove 66 is a groove that extends to a predetermined length along the circumferential direction of the rotating member 6. The fourth groove 66 is provided so as to be continuous with the third groove 65 on the second end 62 side of the rotating member 6. Two fourth grooves 66 are provided on the inner circumferential surface of the rotating member 6 so as to face each other. When the holding member 5 is inserted into the inside of the rotating member 6, the above-mentioned convex portion 55 of the holding member 5 is fitted into the third groove 65 and then moved along the third groove 65. Then, when the convex portion 55 of the holding member 5 reaches the fourth groove 66, the rotating member 6 is rotated so that the convex portion 55 moves along the fourth groove 66, thereby fixing the left-right position of the rotating member 6 in the holding member 5.

Marks marked with numbers from "0" to "5" are provided at regular intervals on the outer periphery of the rotating member 6. These marks are indicators for adjusting the strength of the elastic force F of the torsion spring 3 by the adjustment member 4, as described below.

[1-3. Adjustment of the elastic force of the torsion spring in the seat lifting device]
As shown in Figures 13 and 14, when the adjustment member 4 is moved upward, the abutment surface 641 of the abutment portion 64 of the rotation member 6 is pushed upward by the apex portion 41 of the adjustment member 4, and the position of the abutment surface 641 of the rotation member 6 moves upward with the displacement of the adjustment member 4. When the position of the abutment surface 641 moves upward in this manner, the rotation member 6 rotates on the rotation surface 58 of the holding member 5 in the second torsional direction θ2 around the rotation axis A. As a result, the second end 32 of the torsion spring 3 fixed to the spring hook portion 63 of the rotation member 6 also moves in the second torsional direction θ2. When the rotation member 6 rotates in the second torsional direction θ2 around the rotation axis A in this manner, the torsion angle of the torsion spring 3 increases, so that the torque of the torsion spring 3 increases and the elastic force F of the torsion spring 3 becomes stronger.

As shown in Figs. 15 and 16, when the adjustment member 4 is moved downward, the contact surface 641 of the contact portion 64 of the rotating member 6 moves downward while contacting the apex portion 41 of the adjustment member 4, and the position of the contact surface 641 of the rotating member 6 moves downward with the displacement of the adjustment member 4. When the position of the contact surface 641 moves downward in this manner, the rotating member 6 rotates on the rotation surface 58 of the holding member 5 in the first torsional direction θ1 around the rotation axis A. As a result, the second end 32 of the torsion spring 3 fixed to the spring hook portion 63 of the rotating member 6 also moves in the first torsional direction θ1. When the rotating member 6 rotates in the first torsional direction θ1 around the rotation axis A in this manner, the torsion angle of the torsion spring 3 decreases, so the torque of the torsion spring 3 decreases and the elastic force F of the torsion spring 3 weakens.

In this embodiment, for example, the elastic force F can be measured by aligning the number marks from "0" to "5" on the outer circumferential surface of the rotating member 6 with a reference mark (not shown) on the holding member 5. Specifically, when the adjustment member 4 is operated to rotate the rotating member 6 in a direction in which the "5" mark aligns with the reference mark, the elastic force F of the torsion spring 3 becomes stronger. That is, in FIG. 14, when the adjustment member 4 is pressed in and the rotating member 6 is rotated so that the number mark moves to the back, the elastic force F of the torsion spring 3 becomes stronger. Also, when the adjustment member 4 is operated to rotate the rotating member 6 in a direction in which the "0" mark aligns with the reference mark, the elastic force F of the torsion spring 3 becomes weaker. That is, in FIG. 16, when the adjustment member 4 is loosened and the rotating member 6 is rotated so that the number mark moves forward, the elastic force F of the torsion spring 3 becomes weaker.

2. Effects
According to the embodiment described above in detail, the following effects can be obtained.
(2a) In this embodiment, the rotating member 6 is rotatably attached to the holding member 5, and the position of the rotating member 6, in other words, the rotation angle of the rotating member 6, can be adjusted in accordance with the displacement of the adjustment member 4. As a result, in a state in which the first end 31 of the torsion spring 3 is fixed to the seat frame 11, the second end 32 of the torsion spring 3 rotates and moves in the torsional direction together with the rotating member 6. As a result, the position of the second end 32 in the torsional direction changes. Therefore, by adjusting the position of the rotating member 6 with the adjustment member 4, the elastic force F caused by the torsional deformation of the torsion spring 3 can be strengthened or weakened. Therefore, the speed at which the seat 100 of the chair rotates from the seated position to the standing position can be easily adjusted using the adjustment member 4.

The adjustment member 4 also prevents the elastic force F of the torsion spring 3 from rotating the rotating member 6 in the opposite direction to the rotation of the seat 100 to the upright position. Therefore, the adjustment member 4 abuts against the abutment surface 641, thereby fixing the position of the rotating member 6.

In addition, if the seat 100 is heavy, for example when the back cover of the seat 100 is made of a wooden board, the speed at which the seat 100 rotates from the seated position to the standing position tends to be slow. However, in this embodiment, the speed can be adjusted to match the specifications by adjusting the elastic force F of the torsion spring 3 to a strong value using the adjustment member 4 and assembling the chair. In addition, for example, when the speed at which the seat 100 rotates from the seated position to the standing position becomes uneven due to unevenness of the floor surface or individual differences in part precision at the site where a chair having the seat 100 is assembled, fine adjustments can be made using the adjustment member 4.

(2b) In this embodiment, the contact surface 641 of the rotating member 6 has a curved shape so that a part of the contact surface 641 always contacts the apex 41 of the adjustment member 4 vertically when the rotating member 6 rotates in the torsional direction. Therefore, the force caused by the displacement of the adjustment member 4 is easily applied to the contact surface 641. On the other hand, if the contact surface is flat, when the rotating member 6 rotates in the torsional direction by the adjustment member 4, the contact surface is likely to intersect with the apex 41 at an angle, and the contact surface and the apex 41 are unlikely to contact each other vertically. Therefore, when the contact surface 641 has a curved shape as in this embodiment, the contact surface 641 and the apex 41 are likely to always contact each other vertically, and the force caused by the displacement of the adjustment member 4 is more likely to be applied to the contact surface 641 than when the contact surface is flat.

(2c) In this embodiment, the adjustment member 4 and the rotating member 6 are held by the holding member 5, so that the rotating member 6 and the adjustment member 4 can be easily arranged in the seat lifting device 300. In addition, the function of fixing the rotating member 6 to the rotating support part 14 so that it does not rotate together with the seat 100, the function of holding the second end 32 of the torsion spring 3, and the function of adjusting the strength of the elastic force F of the torsion spring 3 can be configured as a single unit.

(2d) In this embodiment, the holding member 5 is fixed to the rotation support 14, which is fixed to the support column so as not to rotate with the seat 100. Therefore, by using the rotation support 14, the seat lift-up device 300 can be configured with a simple structure without having to provide other parts to fix the holding member 5 so as not to rotate with the seat 100.

(2e) In this embodiment, the strength of the elastic force F due to the torsional deformation of the torsion spring 3 can be easily adjusted based on the marks written with the numbers "0" to "5" provided on the outer peripheral surface of the rotating member 6. In addition, the marks allow the strength of the elastic force F due to the torsional deformation of the torsion spring 3 to be visually confirmed.

3. Other embodiments
Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take various forms.

(3a) In the above embodiment, the configuration in which the adjustment member 4 and the rotating member 6 are held by the holding member 5 is exemplified, but the configuration of the seat lift-up device 300 is not limited to this. For example, the seat lift-up device may be configured not to include the holding member 5. In this case, for example, the rotation support part 14 may hold the rotating member 6 together with the second end 32 of the torsion spring 3 directly or via another member so that it can rotate and move. Also, for example, the rotation support part 14 may have a configuration that can directly hold the adjustment member 4. Also, for example, the adjustment member 4 may be held by another member other than the rotation support part 14 that does not rotate together with the seat 100.

(3b) In the above embodiment, the rotating member 6 is formed in a cylindrical shape, but the shape of the rotating member is not limited to this. For example, the rotating member may be a plate-like member curved to fit along the rotating surface 58 of the holding member 5. In this case, for example, the rotating member may be rotatably held in a groove extending in the circumferential direction provided on the outer circumferential surface of the holding member.

(3c) In the above embodiment, the holding member is formed in a cylindrical shape, but the shape of the holding member is not limited to this. For example, the holding member may have various shapes that have a rotation surface on which the rotating member can rotate and that have a configuration that allows it to be fixed to the rotation support part 14.

(3d) The markings provided on the outer peripheral surface of the rotating member 6 and indicating a guide for adjusting the strength of the elastic force F of the torsion spring 3 may be marked with a number less than "5" or a number greater than "5". Also, for example, the markings may be marked with letters such as "strong" and "weak" instead of numbers.

(3e) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. In addition, part of the configuration of the above embodiments may be omitted. In addition, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. All aspects included in the technical idea identified from the wording of the claims are embodiments of the present disclosure.

3...spring, 4...adjustment member, 5...retaining member, 6...rotating member, 7...stopper, 8, 9...screw, 11...seat frame, 12...seat plate, 13...cushion portion, 14...rotation support portion, 31, 51, 61...first end portion, 32, 52, 62...second end portion, 41...apex portion, 53...first groove, 54...positioning portion, 55...convex portion, 56...fixing portion, 57...mounting portion, 58...rotation surface, 63...spring hook portion, 64...contact portion, 65...third groove, 66...fourth groove, 71...protrusion, 100...seat, 101...seating surface, 111...upper plate, 112...lower plate, 113...left side plate, 114...right side plate, 115...first through hole, 141...shaft, 142...prevention plate, 143...second through hole, 200...backrest, 300...seat lifting device, 561...third through hole, 571...fourth through hole, 572...second groove, 611...notch, 631...hook groove, 632...folded part, 641...contact surface, A...rotation axis, F...elastic force.

Claims (5)

A seat lift-up device for a chair, the seat of which is rotatable about a predetermined rotation axis from a seated position when a user is seated to a standing position when a user is not seated,
a torsion spring having a first end fixed to a seat frame of the seat;
a rotating member to which a second end of the torsion spring opposite to the first end is fixed, the rotating member rotating together with the second end in a torsional direction of the torsion spring;
an adjustment member that is held by a holding member that does not rotate together with the seat portion and adjusts the position of the rotation member;
Equipped with
The seat portion rotates from the seated position to the standing position by an elastic force caused by the torsional deformation of the torsion spring,
a position of the second end portion in the torsional direction is changed by adjusting a position of the rotating member by the adjustment member,
The rotating member is held by the holding member,
The holding member has a mounting portion to which the adjustment member is attached and a rotation surface to which the rotation member is rotatably attached.
Seat lift-up device. The seat lift-up device according to claim 1,
The rotating member has an abutment surface against which the adjustment member abuts, and the position of the abutment surface moves in conjunction with the displacement of the adjustment member, thereby rotating and moving in the torsional direction together with the second end. The seat lift-up device according to claim 2,
the adjustment member has a vertex portion that abuts against the abutment surface,
A seat lift-up device, wherein the abutment surface has a curved shape so that at least a portion of the abutment surface vertically abuts against the apex portion when the rotating member rotates in the torsional direction. The seat lift-up device according to any one of claims 1 to 3,
A rotation support part that rotatably supports the seat frame and does not rotate together with the seat,
The holding member is cylindrical, the rotation support portion passes through the holding member,
The rotation surface is an outer circumferential surface of the holding member,
A seat lift-up device in which the rotating member is cylindrical and the retaining member passes through the rotating surface so as to surround it from the outside . A seat lift-up device according to any one of claims 1 to 4 ,
The seat lift-up device , wherein the rotating member has a mark indicating a guide for adjusting the strength of the elastic force by the adjustment member .

Images