JP2025033030A - chair - Google Patents

Abstract

To realize a chair capable of moving a backrest longitudinally and laterally with a small number of components.SOLUTION: A chair comprises a backrest 7, a back post 5 supporting the backrest, and a member 6 connecting the backrest with the back post in a longitudinally and laterally movable manner. The member 6 comprises a base part 62, an attachment part 61 of the backrest, and a holding part 67. A shape when the base part and the attachment part are viewed from a side face is a U shape, and a shape when the base part and the holding part are viewed from the side face is a reverse C shape. An end of the back post is held by and between the base part and the holding part in the reverse C shape.SELECTED DRAWING: Figure 3

Description

The present invention relates to chairs, particularly chairs for use in offices, etc.

The following patent publications, for example, are examples of prior art that disclose structures for connecting a chair back to a frame, particularly those that connect the back so that it can oscillate:

JP 2020-54430 Publication "Backrest tilt mechanism" In a structure in which the lower end of the backrest is fixed to a synchro frame while the upper part is hooked onto the back frame and supported, the connection between the back frame and the upper part of the backrest is made by fitting a T-shaped locking member provided on the front of the back frame into a pocket portion formed on the back of the backrest. Patent Publication No. 3961283 "Chair" This chair comprises a support body positioned under the seat, a back frame whose base end is supported on the support body so as to be tiltable between an upright position and a backward leaning position, and a swinging body suspended swingably from the tip of the back frame, the front side of the seat is rotatably connected to the support body and the rear end of the seat is rotatably connected only to the swinging body behind the connection point, while a backrest is integrated with or attached to the swinging body, and the support body, back frame, swinging body and seat are rotatably connected to one another to form a four-sided link mechanism, which acts to tilt the backrest and seat in synchronous fashion so that the seat is linked to the tilting movement of the backrest. Patent No. 3993356 "Chair" A cover with an opening window is provided on the rear side of the backrest, and a chair is inserted into the cover through the opening window. In this seat backrest, a shielding member is positioned at a position that covers the gap between the inner edge of the opening window of the cover and the back support rod so as not to interfere with the tilting movement of the backrest, and the shielding member protrudes like a brim around the back support rod and overlaps with the opening window, and this shielding member is plate-shaped forming a hole through which the back support rod passes and an opening/closing portion that opens part of the hole, and when the opening/closing portion is spread out, the back support rod is inserted into the hole, and when the opening/closing portion is closed, the shielding member is positioned so as to surround the periphery of the back support rod, and the back support rod has a recess near the opening window of the cover, and part of the shielding member is engaged with and attached to the seat back support rod, and further, the shielding member has a hook portion that engages with the recess of the back support rod, and this hook portion can be engaged with the recess to fix the shielding member in close contact with the outer surface of the cover. Patent No. 5358821 "Chair" A chair comprising: a backrest with an elastically deformable back shell; a tilting frame supporting a portion of the back shell above the lumbar support portion that supports the waist of a seated person; and a support supporting the lower end or a portion near the lower end of the back shell; the tilting frame and the support are pivotally connected, with the pivot point being set at the rear of the lower end of the back shell; and as the tilting frame tilts backward relative to the support, the back shell undergoes overall curvature deformation so as to cause the lumbar support portion to protrude relatively forward around the pivot point. The tilting frame extends downward from the pivot point and has an overhang portion that extends in a different direction from the upper portion of the support in a side view in the normal state where the backrest is in an upright position; and between the overhang portion and the upper portion of the support, an elastic body is disposed that utilizes a coil spring that is pressed against the overhang portion as the tilting frame tilts backward to accumulate repulsive force. Patent No. 6900478 "Chair" In a chair in which a movable part that moves when subjected to a seated load can move back and forth and left and right relative to a supporting part, a flange portion is provided on the vertical surface of the plate material of the movable part or the supporting part, the flange portion extends horizontally and has a guide surface that moves a rolling element in the longitudinal direction, the horizontal dimension of the guide surface is greater than the thickness of the plate material, the flange portion and the surrounding plate material part constituting the vertical surface are integrally formed from metal, the flange portion is shaped to go around the periphery of a guide hole that opens into the vertical surface, and the rolling elements are arranged to be able to roll independently left and right along the guide surface. Patent No. 7091214 "Spring support structure for chair" A spring mechanism consisting of a first spring mount, a second spring mount, and a compression coil spring arranged between them, which is suspended between the spring mount receiving parts of two members which are pivotally connected to each other by one axis to apply a spring force between the two members, at least one of the spring mount and the spring mount receiving part is a first spring mount receiving part that utilizes a flat portion of a frame material having a surface perpendicular to the direction in which the spring force acts and two flat surfaces along the direction in which the spring force acts, a pair of flanges that sandwich the flat surfaces of the first spring mount receiving part, and a pressure receiving surface between the flanges that abuts against the first spring mount receiving part and receives the force applied to the spring, and a first spring mount with a slit where the distance between the pair of flanges is wider than the distance between the flat surfaces.

Conventional structures for movably connecting a chair back to a frame were complex and had many parts.

In Patent Document 1 and Patent Document 6, the backrest is connected to the frame by a back frame, but the back frame has a large and complex structure that includes multiple parts such as a T-shaped locking portion and a pocket portion.

In Patent Document 2, the backrest connection structure is provided with a back frame and a rocking body that is suspended from the tip of the back frame so that it can rock, but this structure includes multiple parts and is large, about the same size as the chair.

Patent Document 3 discloses a cover for an opening window on the rear side of a backrest. The backrest can also be moved forward and backward because the back support rod moves forward and backward, but it cannot be moved left and right.

Patent Document 4 discloses a backrest connection structure that includes a tilting frame that connects to the backrest at two points above and below, and a coil spring that is pressed against an overhang as the tilting frame tilts backward to accumulate a repulsive force, but this structure includes multiple parts and is as large as the backrest. In addition, the backrest can be moved forward and backward, but not left and right.

In Patent Document 5, the backrest is supported by the back frame via an operating mechanism 6M. The operating mechanism 6M includes a base portion 64 on which an elastic member 65 is arranged, a guide portion 65a arranged adjacent to the base portion 64 and tapered toward the back side, a tilt portion 65 whose center is open in the front-rear direction, and a presser 66 having a convex guide portion 66a corresponding to the guide portion 65a on the front side and fixed to the base portion 64 through the opening of the tilt portion 65 with the guide portion 66a fitted into the guide portion 65a, and includes multiple parts. The back frame also requires a back support portion 61a including multiple parts. This configuration is complex and made up of multiple parts.

The chairs in Patent Documents 1 to 6 above have a spring or other elastic body or cover in the connecting structure between the backrest and the frame, which increases the number of parts, and the structure is bulky, making it difficult to achieve a clean design. Another possible connecting structure would be to insert rubber, but this would also create a bulky look.

The objective of this invention is to provide a structure that is simple, not bulky, requires a small number of parts, and allows the backrest of a chair to be movably connected to a frame.

The present invention is a chair comprising a backrest 7, a back support 5 supporting the backrest, and a member (tilt member/joint member 6) connecting the backrest to the back support so as to be movable forward, backward, left and right,
The member includes a base 62, a mounting portion 61 that is connected to a lower portion of the base and extends upward, and a clamping portion 67 that is connected to an upper portion of the base and extends downward,
The side shape of the base and the mounting part is U-shaped, and the backrest is attached to an upper part of the mounting part,
The side shape of the base portion and the clamping portion is U-shaped,
At least the end of the back support is plate-shaped, and in the connected state, the end of the back support is sandwiched between the base and the clamping portion.

The U-shaped curved portion is, for example, a circular arc (semicircle), but may be other curved lines or a plurality of straight lines. The U-shaped portion is, for example, a straight line, but may include a curved line.
Being movable forward, backward, left and right means that the backrest 7 can sway forward and backward within a certain range as seen by a seated person (swaying the body back and forth, moving in the direction of the arrows in Figures 8(a) and (c)) and left and right (twisting left and right around the torso, rotating around the middle of the backrest mounting part 61 in Figure 7(a)).

a first protrusion (a forward stopper 65) that is connected to a lower portion of the base and extends forward to limit forward movement of the backrest;
A second protrusion (rearward stopper 66) may be provided which is connected to an upper portion of the base and extends forward to limit the rearward movement of the backrest.

It may also be provided with a fitting protrusion 68 that is provided in the middle of the U-shaped space formed by the base and the clamping portion and fits into a recess (joint member fitting recess 52) provided at the end of the back support.

a first cover 101U attached to the back of the backrest so as to close the space between the first protrusion and the backrest and not to hinder the backrest from moving forward, backward, left, and right relative to the back support;
Alternatively, at least one of a second cover 101L may be provided which is attached to the rear surface of the backrest so as to block the space between the second protrusion and the backrest while not hindering forward/backward and left/right movement of the backrest relative to the back support pillar.

According to this invention, the backrest is connected to the back support by the member (tilt member/joint member 6), so the backrest and back support can be connected with a small number of parts, and the backrest can be moved forward, backward, left and right.

1 is a perspective view of a chair according to an embodiment of the present invention; 1 is a three-view diagram of the chair, in which (a) is a plan view, (b) is a front view, and (c) is a right side view. FIG. 3(a) is an enlarged right side view showing the connection between the back support and the backrest by a joint member in the chair, and FIG. 3(b) is a perspective view of the joint member. 2(a), (b), and (c) are cross-sectional perspective views of the back support and the backrest in a connected state (screws for attaching the joint member to the back support are omitted). 13 is an explanatory diagram of the connection between the backrest and the joint member. FIG. Fig. 1 is an explanatory diagram of the connection between the back support and the joint member, Fig. 1 (a1) and (a2) show the state in which the joint member is disposed at the connection position with the backrest, and Fig. 1 (b1) and (b2) show the state in which the joint member is moved upward from the connection position. FIG. 7(a) is a plan view of the joint member, FIG. 7(b) is a front view of the same, and FIG. 7(c) is a bottom view of the same. 8(a) is a right side view of the joint member, FIG. 8(b) is a rear view, and FIG. 8(c) is a left side view. 8(a), 8(b), and 8(c) are cross-sectional perspective views of a joint member, each of which shows a cross-sectional view taken along the arrow in FIG. Figure 10(a) is a right side view of the chair showing the attached state of the upper cover and lower cover, (b) is an enlarged view showing the upper cover and the rear stopper, and (c) is an enlarged view showing the lower cover and the front stopper. FIG. 11(a) is a plan view of the backrest portion with the upper and lower covers attached, and FIG. 11(b) is a rear view of the same (tilt member/joint member 6 is omitted). 12A and 12B are perspective views of the upper cover, and FIGS. 12C and 12D are perspective views of the lower cover.

An embodiment of the present invention will now be described with reference to the drawings.
The chair according to the embodiment of the invention shown in Figures 1 and 2 comprises four legs (two pairs of legs 1, this is an example) arranged to fan outwardly in the front-to-rear direction, and a seat 2 and seat surface 3 placed and fixed on the four legs. The seat surface 3 is a cushioned member (e.g. a mesh member) placed in the middle of the seat 2. The two legs are connected to form a pair of legs 1. An armrest support 4a that curves and extends upward is attached to the outside of the connection position of the two legs of the pair of legs 1 (the connection portion at the upper ends of the two legs), and an armrest 4 is placed on the upper end of the armrest support 4a. A leg connecting member 4b that connects the connection positions of the pair of legs 1 is attached inside the seat 2 below the seat 2.

The seat 2 is a curved, plate-like member (e.g., wood or plastic), and the back support 5 extends upward from the rear end of the seat, curving upward, to the attachment position of the backrest 7 (approximately the middle of the backrest 7). At least the upper end of the back support 5 is plate-like. In the example shown in the figure, the seat 2 and the back support 5 are integrally formed, but this is not limited to this. Also, the back support 5 is supported by being connected to the seat 2, but this is not limited to this. For example, it may be connected to the legs and supported. Also, in the example shown in the figure, the width of the back support 5 is narrower than the width of the seat 2 when viewed from the front, but this is not limited to this.

As shown in FIG. 3(a) and other figures, the backrest 7 is connected to the back support 5 via the tilt member/joint member 6 so that it can tilt. The tilt member/joint member 6 allows the backrest 7 to sway forward and backward (swinging the body forward and backward, movement in the direction of the arrows in FIG. 8(a) and (c)) and left and right (twisting left and right around the trunk, rotation around the middle of the backrest mounting part 61 in FIG. 7(a)) within a certain range as seen by the seated person. In the tilt member/joint member 6, the structure of the backrest mounting part 61 enables the tilting movement described above. On the other hand, the backrest 7 is connected to the back support 5 by the connection (screw fastening) of the backrest 7 at the backrest mounting part 61 and the connection (screw fastening and fitting) of the upper end of the back support 5 by the base (clamping part) 62 and the clamping part 67 (see FIG. 3 to FIG. 6).

As shown in FIG. 5, the backrest 7 is attached to the tilt member/joint member 6 by two mounting screws 8. Through holes 71 for the screws are provided in the backrest 7, through which the mounting screws 8 are screwed into the mounting screw engagement holes 63. The mounting screw engagement holes 63 are either female-threaded or equipped with nuts. In the example shown in FIG. 5, a mounting cover 9 is provided to cover the mounting screws 8. The through holes 71 in the backrest 7 and their periphery are provided with recesses 73 for receiving the mounting cover 9. The recesses 73 are provided with engagement holes 72 for the mounting claws 91 provided on the inside of the mounting cover 9. See FIG. 4 for the state in which the backrest 7 is attached to the back support 5. The mounting cover 9 hides the heads of the mounting screws 8, making them invisible.

Figure 6 is an explanatory diagram of the connection between the back support 5 and the joint member 6. The backrest 7 is omitted in the figure. The tilt member/joint member 6 is fitted into the recesses 52, 53 provided at the upper end of the back support 5, and is further fixed by an attachment screw (not shown). As shown in (b1) and (b2) of the figure, an attachment screw through hole 51 for attaching the tilt member/joint member 6 to the back support 5 and a slit-shaped joint member fitting recess 52 are provided so as to penetrate from the front side of the upper end of the back support 5 to the back side, and a recess 53 for the joint member is provided on the back side. The recess 53 is formed by recessing the upper end of the back support 5 to match the shape and thickness of the clamping part 67. The thickness of the recess 53 is determined according to the distance between the base (clamping part) 62 and the clamping part 67, and is the same as or slightly smaller than the distance. In addition, although not indicated by a symbol, a recess is provided around the attachment screw through hole 51 on the back side, and a female thread part such as a nut (not shown) is arranged here. As shown in (a1) and (a2) of the same figure, the tilt member/joint member 6 is attached to the upper end of the back support 5, and the two are fixed together by threading the mounting screws (not shown) through the mounting screw through holes 51 and 64 into the female threads (not shown). Together with the fit of the recesses 52 and 53, the two are firmly fixed together.

The tilt member/joint member 6 will now be described with reference to FIGS.
The tilt member/joint member 6 is integrally formed from a tough resin (e.g., a nylon member containing glass). The tilt member/joint member 6 includes a plate-shaped base 62, a backrest attachment part 61 connected to the lower part of the base 62, and a plate-shaped clamping part 67 connected to the base 62 on the opposite side of the backrest attachment part 61 when viewed from the side. The base 62 and the backrest attachment part 61 have a U-shape when viewed from the side. The base 62 and the clamping part 67 have a U-shape when viewed from the side. The base (clamping part) 62 and the clamping part 67 clamp the end of the plate-shaped back support 5 (see Figs. 3(a), 4 and 6).

As shown in Figure 7, when viewed from the front, the backrest attachment part 61 widens from the joining position of the base part 62 upwards, and is roughly an inverted trapezoid (the top side is larger than the bottom side). Mounting screw engagement holes 63 are provided near both ends of the top side, and a cylindrical protrusion is provided concentric with the center of the holes. The surface of this protrusion contacts the back surface of the backrest 7 (see Figure 4 (a)). The mounting screw engagement hole 63 has a female thread or a nut embedded inside. The arrow in Figure 7 (a) indicates that it can be moved left and right (twisting direction).

As shown in FIG. 8, when viewed from the side, the backrest attachment part 61 curves from the joining position of the base part 62 from below to above, and extends parallel to the base part 62. The curved part is roughly a semicircle. The curved part of the backrest attachment part 61, the parallel part, and a part of the base part 62 (the part facing the backrest attachment part 61) form a U-shape. The diameter of the semicircle part corresponds to the distance between the backrest attachment part 61 and the base part 62. This distance corresponds to the amount of movement in the left-right direction (twist direction). Note that the semicircle part does not have to be a strict semicircle in the geometric sense. It may be some kind of curve or multiple straight lines that create a predetermined distance between the backrest attachment part 61 and the base part 62. The arrows in FIG. 8(a) and (c) indicate that it can move in the forward and backward directions.

As configured as described above, the backrest 7 attached to the backrest attachment part 61 can be tilted. A seated person can move the backrest 7 back and forth and left and right. The tilt member/joint member 6 is made of a sturdy and flexible material, so the backrest attachment part 61 can bend mainly at the joint with the base part 62, and can move within a certain range relative to the base part 62. As shown by the arrow in Figure 7(a), the part of the attachment screw engagement hole 63 can be moved back and forth, and this allows the backrest 7 to be rotated (twisted) left and right about the center. The range of rotation can be increased or decreased by adjusting the width of the U-shape, i.e., the distance between the attachment part 61 and the base part 62.

As shown in Figures 8(a) and 8(c), the mounting screw engagement hole 63 can be moved back and forth, allowing the backrest 7 to be tilted forward and backward. In addition, since the back support 5 also has a certain degree of flexibility, the entire backrest 7 can also be moved forward and backward.

The tilt member/joint member 6 is connected to the lower part of the base 62 and is equipped with a forward stopper (first protrusion) 65 that limits the forward movement of the backrest 7. The forward direction is the left direction of the arrow in Figure 8(a). When the backrest 7 tilts forward, its back surface comes into contact with the tip of the stopper 65, restricting movement due to tilt. In the example shown in the figure, the stopper 65 extends below the base 62 and is bent 90 degrees forward (to the left). The position of the tip of the stopper 65 is determined according to the range of tilt of the backrest 7.

The tilt member/joint member 6 is connected to the top of the base 62 and is equipped with a rearward stopper (second protrusion) 66 that limits the rearward movement of the backrest 7. The forward direction is the right direction of the arrow in Figure 8(a). When the backrest 7 tilts rearward, its underside comes into contact with the tip of the stopper 66, restricting movement due to tilt. In the example shown in the figure, the stopper 66 is configured by extending the upper end of the base 62 or the end of the clamping part 67 forward (to the left). The position of the tip of the stopper 66 is determined according to the range of tilt of the backrest 7.

The clamping portion 67 is provided parallel to the base portion 62, and their upper ends are connected to each other, forming a U-shaped space for clamping the back support 5 (see Figs. 8(a) and (c)). A plate-shaped mating protrusion 68 is provided in the center of the U-shaped space to penetrate the slit 52 of the back support 5 (see Figs. 4(c), 8, and 9(c)).

The inner surfaces of the base 62 and the clamping portion 67, i.e., the surfaces facing the U-shaped space, are each provided with a protrusion 69 (see Fig. 7(c), Fig. 9(a) and (b)). The protrusion 69 functions as a rib to suppress rattling of the punch taper during molding.

A gap (space) is generated between the backrest 7 and the stoppers 65, 66 (see symbols A and B in Fig. 10(b) and (c)). A cover may be provided to close this gap. Fig. 10 and Fig. 11 show the state in which a lower cover 101L that closes the gap marked A and an upper cover 101U that closes the gap marked B are attached to the back of the backrest 7. Fig. 12 shows a perspective view of the lower cover 101L and the upper cover 101U.

Both of these covers 101L and 101U are roughly L-shaped when viewed from the side, with one side of the L attached to the backrest 7 by a mounting screw (not shown), and the other side protruding near the inner surface of the stoppers 65, 66 (see FIG. 10). The tip P is located above the stopper 65, and the tip Q is located below the stopper 66 (see FIG. 10 (b) (c)). The covers 101L and 101U close the gaps A and B to prevent objects from getting caught there. The tips P and Q of the covers 101L and 101U move with reclining, but the length of the tips is just enough to close the gaps A and B, and is not longer than necessary. Therefore, the tips P and Q of the covers 101L and 101U can move without hitting the inner surface of the stoppers 65, 66 when reclining (they may hit when the reclining range or a predetermined range is exceeded). In other words, the lower cover 101L closes the gap (space) A between the front stopper 65 and the backrest 7, without impeding the movement of the backrest 7 in any direction relative to the back support 5. The same is true for the upper cover 101U. The tip positions of the tip portions P and Q may be set so as to limit the reclining range within a certain range. In this case as well, reclining is possible within a specified range, and it can be said that the movement of the backrest 7 in any direction relative to the back support 5 is not impeded.

As can be seen from FIG. 11(a), the width of the upper cover 101U is smaller than the tilt member/joint member 6. As can be seen from FIG. 11(b), the width of the lower cover 101L is smaller than the upper cover 101U. These widths are determined according to the size of the part that needs to be prevented from getting caught.

In the example shown in the figure, both an upper cover 101U and a lower cover 101L are provided, but this is not essential and only one of them may be provided.

According to the embodiment of the invention, the backrest 7 is attached to the back support 5 by the tilt member/joint member 6 having the above-mentioned structure, so that the backrest 7 can be movably connected to the back support 5. A reclining chair can be provided with a small number of parts. For example, a relatively simple wooden chair does not have a reclining mechanism, but reclining can be achieved by the embodiment of the invention.

REFERENCE SIGNS LIST 1 Pair of legs 2 Seat 3 Seat surface 4 Armrest 4a Armrest support 4b Leg connecting member 5 Back support 51 Mounting screw through hole 52 Joint member fitting recess 53 Recess for joint member 6 Tilt member/joint member 61 Backrest mounting portion 62 Base (clamping portion)
63 Mounting screw engagement hole 64 Mounting screw through hole 65 Front stopper (first protrusion)
66 Rear stopper (second protrusion)
67 Clamping portion 68 Fitting protrusion 69 Protrusion 7 Backrest 71 Mounting screw through hole 72 Mounting claw engagement hole 73 Recess for mounting portion cover 8 Mounting screw for backrest 9 Backrest mounting portion cover 91 Mounting claw 100L Lower cover (first cover)
101U Upper cover (second cover)
102 Mounting screw through hole 103 Mounting screw through hole P Tip of lower cover Q Tip of upper cover

Claims (4)

A chair comprising a backrest, a back support supporting the backrest, and a member connecting the backrest to the back support so as to be movable forward, backward, left and right,
The member includes a base, a mounting portion coupled to a lower portion of the base and extending upward, and a clamping portion coupled to an upper portion of the base and extending downward,
The side shape of the base and the mounting part is U-shaped, and the backrest is attached to an upper part of the mounting part,
The side shape of the base portion and the clamping portion is U-shaped,
A chair characterized in that at least the end of the back support is plate-shaped, and in a connected state, the end of the back support is sandwiched between the base and the clamping portion. a first protrusion coupled to a lower portion of the base and extending forward to limit forward movement of the backrest;
2. The chair of claim 1, further comprising a second protrusion coupled to an upper portion of the base and extending forward to limit rearward movement of the backrest. a first cover attached to the back of the backrest so as to close the space between the first protrusion and the backrest and not to hinder forward/backward and left/right movement of the backrest relative to the back support;
Alternatively, the chair according to claim 2 further comprises at least one second cover attached to the rear surface of the backrest so as to block the space between the second protrusion and the backrest while not hindering forward/backward and left/right movement of the backrest relative to the back support pillar. The chair according to any one of claims 1 to 3, characterized in that it has a fitting protrusion that is provided in the middle of the U-shaped space formed by the base and the clamping part and fits into a recess provided at the end of the back support.

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