JP7464381B2 - Chair base for nesting chairs - Google Patents

Description

The present invention relates to a base for forming a chair in which a seat body having a seat and a backrest (this seat body includes both those in which the backrest and seat are integrated and those which are separate; the same applies hereinafter) can be changed in position from a seated position (position when in use) approximately parallel to the floor surface to an upright position (position when not in use) by utilizing the repulsive force (hereinafter also referred to as spring force) of a torsion spring, and can be stacked (hereinafter referred to as nesting) in the front-to-back direction on the floor surface.

Conventionally, there are chairs that can be stacked vertically or nested front to back when not in use, thereby reducing the footprint they take up when not in use and improving space efficiency when stored.

There are two types of nestable chairs: one in which the seat and backrest are one unit and the seat body is raised and lowered, and one in which only the seat surface is separate from the backrest. Chairs in which the seat body is raised and lowered and the seat body is an integrated unit are known from Patent Documents 1 to 3, for example.

In nestable chairs with a seat body in which the backrest and seat are one unit, the seat body and legs are connected via a connecting mechanism, which supports the seat body so that it can rotate between a reclined position and an upright position. If the connecting mechanism is provided on both the left and right sides of the underside of the seat body or on the left and right sides of the seat body, a cover member is provided to cover the connecting mechanism, but the cover member is provided in a position that is visible from the outside and can be considered an eyesore. In addition, some conventional nesting chairs have a support part that supports the reclined position of the seat body from below when in use and is provided in a conspicuous position on the leg. Furthermore, if a cushioning member is provided on the leg to prevent damage to the constituent parts of the chairs due to collisions between the nested chairs and to arrange the chairs in an orderly manner, the support part and the cushioning member can be considered an eyesore.

Patent No. 3321727 JP2007-130478A Patent No. 6527623

The present invention aims to provide a base for a nestable chair in which a seat body, which has a seat and backrest , and legs are connected via a connecting mechanism so that they can be raised and lowered freely, by housing the connecting mechanism inside a seat support cover that supports the seat body with its underside, and by arranging the support part of the seat body in a lying position and a cushioning member that prevents damage and ensures alignment when nested inside the seat support cover, thereby achieving a smart design in which the support parts and cushioning members are hardly visible from the outside when the chair is in use.

The base of the present invention, which has been devised to solve the above-mentioned problems, is a base for a nestable chair comprising a seat cover for attaching the seat surface of a seat body having a seat surface and a backrest to the upper surface thereof, a bracket to which the seat cover is rotatably connected via a torsion spring and a support shaft coaxial with the torsion spring between a lying position approximately parallel to the floor and an upright position at a desired angle, and the legs including a cross member having the bracket and a support part for supporting the seat cover in the lying position disposed near the center, wherein the seat cover and the bracket are provided with a connecting mechanism, which connects the seat cover and the bracket near the center of the seat cover and near the center of the cross member by the support shaft which passes through an axial hole of the seat cover and a bearing of the bracket , and the torsion spring supported by the support shaft, and the connecting mechanism and the support part are disposed inside the tip of the seat cover in the lying position.

In the present invention, the horizontal member of the leg is provided with the bracket facing forward near the center of the horizontal member on the underside of the front part of the seat support cover, and the support part on the opposite side of the bracket . Furthermore , the horizontal member or the support part is provided with a shock-absorbing member that abuts against the base or seat of the front or rear chair when nested. With this configuration, the support part that supports the reclining position of the seat body and the shock-absorbing member for preventing scratches and aligning when nested are almost invisible from the outside when the chair is in use, demonstrating a smart design.

The cushioning member provided near the center of the horizontal member abuts against the support part of the front chair when nesting. Instead of providing the cushioning member on the horizontal member, it can be provided on the support part or on the underside of the seat cover near the support part by molding it as one piece with the seat cover. The tip of the seat of the rear chair abuts against the cushioning member that is integrated with the support part or seat cover while being cushioned. If a magnet is embedded in the cushioning member provided on the horizontal member to give it magnetic force, the magnet will attract a support made of a magnetic material such as steel, thereby supporting the alignment of the nested chairs.

The legs are formed by arranging two leg frames, each formed of the horizontal and vertical members, in a roughly gate-like shape in front view, one behind the other, with the left-right width of the vertical member of the front leg frame being greater than the left-right width of the vertical member of the rear leg frame . The vertical members of the front and rear leg frames connect the front and rear horizontal members so as to form a roughly inverted V shape in side view, and the connected horizontal members are disposed on the underside of the seat body, so that the horizontal members are generally hidden and invisible under the seat body in a lying position in a plan view. As a result, in a nesting chair using the base of the present invention, when viewed in an upright position during use, only the legs are visible under the seat , giving a novel impression for a nesting chair.

The connecting mechanism of the chair base is equipped with a rotation restriction mechanism for the seat cover, and when the seat cover rotates from the lying position to the standing position, the stopper wall abuts against the bracket to restrict the standing rotation of the seat cover to the standing angle set for the seat body.

The seat support cover has an insertion hole at the front end of the upper surface of a roughly dish-shaped body into which the front end of the bracket enters from below, support walls erected on both sides of the insertion hole, and a stopper wall erected next to the support wall which regulates the erect angle of the seat support cover by working in cooperation with the bracket, and the bracket which enters the insertion hole has a bearing at its tip coaxially with the axial holes of the support wall and stopper wall.

The rotation restriction mechanism is formed by the stopper wall that is integrated with the connected seat cover and the bracket itself, so there is no need for separate, independent parts, and the structure is simple, easy to assemble, and less prone to malfunctions.

The torsion spring is adjusted so that its repulsive force is approximately balanced with the load acting on the torsion spring at a position (hereinafter referred to as the intermediate position) between the upright angle of the seat body or seat surface including the seat support cover when not in use and the reclined angle when in use.

The repulsive force of the torsion spring is adjusted as described above, so that when the seat cover with the seat body placed on it is pushed in the upright direction with a hand placed on the seat body at an intermediate position between the upright angle and the downright angle, it stands up, and when pushed in the downright direction, the seat body's own weight overcomes the repulsive force of the torsion spring and it falls, performing a gentle movement without any shock at the upright end and the downright end.

The torsion spring is installed inside the seat cover with high support stability because the support shaft inserted into the coil portion is inserted through the shaft hole of the support wall and the stopper wall provided near the center of the front end side of the seat cover and the bearing of the bracket provided near the center of the horizontal member. The torsion spring is detachably fixed at one end to the fixed system of the leg including the bracket, and the other end to the movable system of the seat cover. The spring force (repulsive force) of the torsion spring can be adjusted by changing the fixed position of the fixed system around the support shaft. The support shaft of the torsion spring is supported by multiple sets of shaft holes and bearings near the center of the seat cover and the horizontal member , so that the connection between the center of the seat cover and the center of the bracket is strong and stable.

The seat cover and the support part can be provided with a contact retaining member on the seat cover or on the support part with which the seat cover contacts, to assist the contact retaining member in maintaining the state in which the seat cover contacts the support part at the end of the downward rotation of the seat body including the seat cover.

In the base of the present invention, the support part can be made of a magnetic material such as steel, and the seat cover can be configured to have a magnet as a contact holding member at the part that contacts the support part. The magnet is provided on the seat cover in a non-contact state with the support part, so that there is no metallic sound when it contacts the support part, and the magnet does not hit the support part and damage the coating.

A contact support member is provided on the seat cover or the support portion with which the seat cover contacts, and the contact retaining member can maintain the state in which the seat cover contacts the support portion at the end of the downward rotation of the seat body including the seat cover.

When the stopper wall of the seat cover abuts against the bracket at the end of the seat body's upright rotation, if a click member that resiliently engages with the seat cover is provided on the bracket, the click member resiliently engages with the seat cover, allowing the abutment to be felt by a clicking sensation, and the seat cover can be held in the abutting position.

The brackets are installed at two locations near the center of the horizontal member. This positions the connecting mechanism between the seat cover and the bracket at the center of the horizontal member. The bracket is formed of a tube having two vertical walls with spaced apart ends, and the two vertical walls are provided with bearings for the support shaft. The bracket acts as a regulating wall for the stopper wall around which the upper wall of the tube rotates.

The support walls of the seat cover are erected on the left and right sides of the bracket insertion hole of the seat cover, and are positioned to sandwich the tip of the bracket inserted into the insertion hole from below. Also, the stopper wall of the seat cover is positioned between the two erect walls of the tip of the bracket.

In the present invention, the base of a nestable chair is equipped with a connecting mechanism in which the seat support cover and bracket support a torsion spring near the center of both and are connected by a support shaft that passes through an axle hole in the seat support cover and a bearing in the bracket, and the connecting mechanism and the support part that supports the seat in the collapsed position are arranged to fit within the underside of the seat support cover in the collapsed position, and further the support part and the cushioning member that prevents damage and ensures alignment when nesting are also arranged to fit within the underside of the seat support cover.When applied to a nesting chair, when in use, only the seat and legs of the chair are visible when a person is standing, demonstrating a smart design that is unusual for a nesting chair.

FIG. 1 is a perspective view of an example of a nesting chair using the base of the present invention. FIG. 2 is a front view of the chair of FIG. 1 . FIG. 2 is a rear view of the chair of FIG. 1 . FIG. 2 is a bottom view of the chair of FIG. 1 . FIG. 2 is a bottom view of the chair of FIG. 1 . FIG. 6 is a left side view of the chair of FIGS. 1 to 5 with the seat raised; 13 is a side view showing the relationship between the support portion of the seat support cover and the cushioning member during nesting. FIG. FIG. 7 is an enlarged cross-sectional view of part A in FIG. 6 . 6 is an enlarged plan view of the chair of FIG. 1 to FIG. 5 with the seat body removed to show the seat support cover; FIG. 10 is a bottom view of the seat support cover of FIG. 9 . FIG . FIG. 12 is an exploded perspective view of the seat support cover and the leg body of FIG. 11 . 13 is an enlarged cross-sectional side view showing a schematic diagram of a relationship between a stopper wall and a bracket of a connecting mechanism between the seat support cover and the bracket. FIG.

Next, an embodiment of a nestable chair having a seat body mounted on a base body of the present invention will be described with reference to the drawings.
In the figure, reference numeral 1 denotes a seat body having a seat surface 1a and a backrest 1b, and in the figure, the seat surface 1a and the backrest 1b are integrally formed from a synthetic resin molded body. The structure of the seat body 1 is not limited to the example shown in the figure, and other configurations may be used as long as the seat surface 1a and the backrest 1b are integral. There are also seat bodies 1 in which the seat surface 1a and the backrest 1b are separate. In this embodiment, the seat body 1 includes a seat surface that is separate from the backrest.

Reference numeral 2 denotes a seat cover formed of a shallow dish-shaped body on which the seat body 1 can be detachably installed. As shown in Fig . 9 (plan view) and Fig. 10 (bottom view), the seat cover 2 has two insertion holes 2a, each of which is substantially rectangular in plan view, near the center of the front end, into which a bracket 3 (described later) is inserted from below. On the upper surface of the seat cover 2, two support walls 2b are provided to sandwich each insertion hole 2a from the left and right, and two stopper walls 2c are provided between the two support walls 2b. The support walls 2b and the stopper walls 2c are integrally molded with the seat cover 2. The support walls 2b and the stopper walls 2c are provided with a shaft hole Sh through which a support shaft 7 (described later) passes, and a bearing Sb provided at the tip of the bracket 3 is coaxially aligned with the shaft hole Sh. 2e are bolt holes or the like for attaching the seat body 1 or the seat surface (not shown) separate from the backrest, and are provided at four locations near the outer periphery of the seat cover. This allows a plurality of different seat bodies 1 with different designs to be attached to the seat cover 2. When the seat body 1 of the chair is removed to perform maintenance on the internal rotation mechanism of the seat cover 2, the bolt holes 2e must be used, so the seat cover 2 must be held in a collapsed position. To keep the seat cover 2 in a collapsed position, two jig holes 2f are provided in the front of the seat cover 2. When a pin-shaped jig member (not shown) is inserted into the jig hole 2f, even if the seat cover 2 tries to stand up, the jig member hits the buffer member 9 provided on the horizontal member 4b (described later) and prevents the seat cover 2 from standing up and rotating, so the seat cover 2 can be held in a substantially horizontal position for maintenance work.

With the above-described configuration of the seat support cover 2 and bracket 3, all of the components that constitute the connection between the seat support cover 2 and bracket 3, which raises and lowers the seat body 1, are contained within the internal space near the center of the front end of the seat support cover 2 formed by the upper surface of the seat support cover 2 and the lower surface of the seat body 1, and the connection part and rotation control mechanism are not exposed to the outside.

4 and 5 are two leg frames that are roughly gate-shaped when viewed from the front, with horizontal members 4a and 5a that are roughly parallel to the floor on top of left and right vertical members 4b and 5b. For nesting purposes, the left and right widths of the left and right vertical members 4b of the leg frame 4 on the near side (front) when viewed from the front are larger than the left and right vertical members 5b of the leg frame 5 on the far side (rear). The two leg frames 4 and 5 are integrated with their respective horizontal members 4a and 5a overlapping in the front-to-rear direction to form the legs.

The combined front and rear leg frames 4, 5 have vertical members 4b, 5b that are formed in a roughly inverted V shape when viewed from the side. With this configuration, when the chair of the present invention is viewed from the perspective of a person standing in use, only the front and rear leg frames 4, 5 appear to extend diagonally downward from a single point on the underside of the seat support cover 2, which is a distinctive design feature.

As shown in Fig. 12, two brackets 3, 3 are provided in parallel with each other near the center of the horizontal members 4a, 5a integrated with the leg frames 4, 5, protruding toward the front of the seat cover 2, and a support part 6, which is approximately U-shaped in plan view, is provided in the opposite direction to the brackets 3. The support part 6 is a member that supports the lying position of the seat body 1 from below. The horizontal members 4a, 5a are provided with a buffer member 9 that abuts against the support part 6 of the front chair when nesting. The buffer member 9 can be installed at the center of the support part 6 or the underside of the seat cover 2 instead of the horizontal members 4a, 5a. When the buffer member 9 is installed on the support part 6 or the seat cover 2, the tip of the nested rear chair is buffered. The buffer member 9 of the seat cover 2 is molded as a single piece when the seat cover 2 is a resin molded product. 4c, 5c are casters provided at the lower ends of the vertical members 4b, 5b of the leg frames 4, 5.

The seat support cover 2 and bracket 3 have a coaxial shaft hole Sh in the support wall 2b and stopper wall 2c integrally molded on the seat support cover 2, and the left and right brackets 3 exposed on the upper surface side of the seat support cover 2 from the two insertion holes 2a of the seat support cover 2 have bearings Sb coaxial with the shaft hole Sh. When a support shaft 7 is disposed passing through the shaft hole Sh and the bearings Sb, the seat support cover 2 and bracket 3 are rotatably connected (see Figures 9 to 12).

The support shaft 7 is inserted into the coil portion of the torsion spring 8 , so that the torsion spring 8 is disposed at the front end of the seat support cover 2 together with the support shaft 7. One end 8a of the disposed torsion spring 8 is fixed to the movable system of the seat support cover 2, and the other end 8b is fixed to the fixed system of the leg frames 4, 5 including the bracket 3. 81a is a fixing member for fixing the one end 8a to the seat support cover 2 (see Figures 11 and 12) . Note that the fixing member 81a is attached by pressing the one end 8a of the torsion spring 8 against the underside of the seat support cover 2 with a screw 81b, so that it is practically impossible for one person to press the fixing member 81a and tighten the screw 81b. However, if the front end of the fixing member 81a can be supported by hooking it onto a locking portion (not shown) provided on the seat cover 2, assembly becomes easier because the front end of the fixing member 81a can be hooked onto the locking portion and the fixing member 81a can be held down with one hand while the screw 81b can be tightened with the other hand. The torsion spring 8 biases the bracket 3 and seat cover 2, which are rotatably connected by the support shaft 7, in the direction that causes the seat cover 2 to stand up.

In the base of the present invention, the upright angle of the seat body 1 placed on the seat support cover 2 is set, for example, in the range of 60 degrees to 30 degrees, preferably 45 degrees to 35 degrees. In this setting, the repulsive force (spring force) of the torsion spring 8 is adjusted so that the seat body 1 at the intermediate position between the collapsed angle and the upright angle of the seat body 1 is approximately balanced with the load acting on the torsion spring 8. If the spring force is approximately balanced with the load of the seat body 1 at the intermediate position, when the seat body 1 is in a collapsed position (approximately parallel to the floor), the spring force of the torsion spring 8 becomes smaller than the load of the seat body 1 acting on this torsion spring 8 (the balance between the load of the seat body 1 rotating in the collapsed side and the spring force is lost), so the seat body 1 rotates in the collapsed side under its own weight and reaches the collapse end, so the collapsed position can be maintained without the need for a locking mechanism.

In the nesting chair using the base of the present invention, the load of the seat body 1 acting on the torsion spring 8 is balanced with the repulsive force of the torsion spring 8 at an angle intermediate between the upright angle and the downright angle of the seat body 1. Therefore, the load against the spring force of the seat body 1 gradually decreases during the upright movement from the intermediate position to the upright end, and the seat body 1 rises gently. The upright end is obtained when the upper surface 22c of the stopper wall 2c provided on the seat support cover 2 abuts against the upper wall 3a of the inner surface of the bracket 3, and the seat body 1 is held at that position by the spring force. On the other hand, the seat body 1 falls gently because the load against the spring force of the seat body 1 gradually increases from the intermediate position onwards. The downright end is obtained when the abutment part 21 provided on the lower surface 2d of the seat support cover 2 abuts against the upper surface 6a of the support part 6 provided on the leg frame 4, 5, and the seat body 1 is held at that position by its own weight.

In addition, in the chair, the spring force of the torsion spring 8 is adjusted to be in balance with the load of the seat body 1 acting on the torsion spring 8 in the intermediate position (angle at the intermediate position between the standing angle and the collapsed angle) between the standing position (standing angle) and the collapsed position (collapsed angle). As a result, the load on the spring force of the seat body 1, which changes its position as it stands up, gradually decreases from the intermediate position toward the standing end, so the seat body 1 reaches the standing end with the spring force. On the other hand, from the intermediate point where the spring force and the load of the seat body 1 are in balance toward the collapse end, the seat body 1 falls to the horizontal side and the load on the spring force gradually increases, so the seat body 1 reaches the collapse end under its own weight while receiving the cushioning effect of the spring force. In this way, the seat body 1 performs a gentle rise and fall movement because the spring force is adjusted to be in balance with the load of the seat body at the intermediate position of its rise and fall range.

The rising end of the seat body 1, which rises gently as described above, can be detected by the abutment of the stopper wall 2c and the bracket 3 (the upper surface 22c of the stopper wall 2c abuts the upper wall 3a of the bracket 3). As an example, as shown in FIG. 13 , if a click member 3b having a protrusion 33b that resiliently engages with the seat support cover 2 in the rising end position is arranged on the bracket 3, the protrusion 33b resiliently engages with the front end of the insertion hole 2a on the lower surface 2d of the seat support cover 2 at the rising end of the seat body 1, so that the abutment can be detected with a clicking sensation. In FIG. 13 , a click member 3b having a resilient protrusion 33b is arranged on the bracket 3, and when the seat support cover 2 rotates to the rising end side, the recessed edge 23c of the rising seat support cover 2 repels the protrusion 33b and engages with the click member 3b, so that the rising end of the seat body 1 can be detected with a clicking sensation and the rising end position can be maintained by this series of actions.

The end of the seat body 1 can be detected by the lower surface 2d of the seat cover 2 abutting against the upper surface 6a of the support part 6 , and the abutting state can be maintained by the weight of the seat body 1 including the seat cover 2. In order to detect this end of the seat body 1 with a clicking sensation, for example, a synthetic resin abutment part 21 having a magnet 21a as an abutment holding member can be provided on the lower surface 2d of the seat cover 2 facing the upper surface 6a of the support part 6 shown in FIG. 8. In this way, when the abutment part 21 of the seat cover 2 abuts against the support part 6, the magnet 21a attracts the support part 6, so that the end of the seat body 1 can be detected with a clicking sensation by the magnetic attraction sensation, and the seat body 1 can be held in that position. The magnet 21a can be provided on the surface or inside of the abutment part 21, or the abutment part 21 itself can be formed of a magnet. The magnet 21a can also be provided on the side of the support part 6. Also, a member that maintains the contact between the support portion 6 and the seat cover 2 by a frictional engagement force can be provided instead of the magnet. It is preferable that the magnet 21a is provided without contacting the other side to be attracted. For this reason, in the example shown in Figure 8, the magnet 21a is embedded in the contact portion 21 with its surface exposed.

In the base for nesting chairs of the present invention, the support parts for the seat in a collapsed position and the cushioning members for nesting are arranged so that they are not visible from the outside when the chair is in use, making it possible to form nesting chairs that can demonstrate a smart design. In addition, different types of seats, such as those with different designs, can be attached by replacing them with the seat support cover of the base of the present invention of the same specifications, so multiple types of nesting chairs with different designs can be formed using a single chair base.

Reference Signs List 1: seat body 2: seat support cover 3: brackets 4, 5: leg frame 6: support portion 7: support shaft 8: torsion spring 9: cushioning member

Claims (5)

A base for a nestable chair comprising : a seat cover for attaching the seat surface of a seat body having a seat surface and a backrest to an upper surface thereof; a bracket to which the seat cover is rotatably connected via a torsion spring and a support shaft coaxial with the torsion spring between a lying position approximately parallel to the floor and an upright position at a desired angle; and legs including a horizontal member having a support portion for the bracket and the seat cover in the lying position disposed near the center ,
a connecting mechanism is provided in which the seat cover and the bracket are connected at a front end portion of the seat cover and near the center of the horizontal member by the support shaft that passes through an axial hole of the seat cover and a bearing of the bracket, and the torsion spring that is supported by the support shaft ;
The base of a chair, wherein the connecting mechanism is housed inside the seat support cover, and the support portion is located below the underside of the seat support cover in a laid-down position. The chair base of claim 1, wherein the cross member has a forward-facing bracket near the center and a support portion facing opposite the bracket , and the cross member or the support portion is further provided with a cushioning member that abuts against the front or rear chair base when nested. 3. The chair base according to claim 2, wherein said cushioning member is provided near the center of said horizontal member and abuts against a support portion of the preceding chair when nested. 4. The chair base according to claim 2 or 3, wherein said cushioning member has a magnetic force. The base of a chair according to any one of claims 1 to 4, wherein the leg portion comprises two leg frames formed of horizontal members and vertical members, each of which is roughly gate-shaped when viewed from the front, arranged front to back, the left and right width of the front leg frame being larger than the left and right width of the rear leg frame, the vertical members of the front and rear leg frames being connected by the front and rear horizontal members so as to form a roughly inverted V shape when viewed from the side, and the horizontal members being attached to the underside of the seat support cover of the seat body .

Images