JP2023073034A - Chair and backrest thereof - Google Patents

Abstract

To disclose a structure for attaching to a back frame while a backrest plate applies tension in a backrest in which the backrest plate is made of a soft material such as elastomer.SOLUTION: A reinforcing member 6, 7 is joined to an upper end part and a lower end part of a backrest plate 5 by insert molding. An upper reinforcing member 6 is connected to an upper support body 9 in a manner not to be separated by using an engaging nail. In a lower reinforcing member 7, a block-shaped lower engaging protrusion 18 is formed and fits in a lower engaging recess 19 of a lower support body 10. By bringing the lower reinforcing member 7 into contact with an outward inner surface of the lower engaging recess 19 from the outside, the lower reinforcing member is temporarily attached to the lower support body 10 while keeping the backrest plate 5 in an expanded state. Therefore, an operator can screw a machine screw 24 in a nut 67 by removing a hand from the backrest plate 5. By using softness of a material, the backrest with excellent cushioning properties and fitness can be provided in a stable quality.SELECTED DRAWING: Figure 8

Description

The present invention relates to a chair and its backrest, and is particularly suitable for a backrest that is used with a backrest plate exposed without providing a cushion material and a chair equipped with the same.

A backrest is an important element in a chair, and various devices have been devised to pursue comfort. The important elements that give comfort to the backrest are fit, cushioning, and softness to the touch. Therefore, the front of the backrest is made of cushioning material or mesh material supports the body. The mesh material also has the advantage of being able to prevent stuffiness due to its excellent breathability.

Now, when the seated person leans back on the backrest, the center line of the upper body is not necessarily aligned with the center line of the backrest. In some cases, the backrest is twisted to the left and turned backward. In these cases, the pressing force (body pressure) due to the leaning of the seated person acts strongly on the left or right side of the backrest.

In many cases, the backrest of a chair is basically rigid enough not to be deformed by the pressing force of the seated person. In this case, a part of the body is strongly pressed against a part of the backrest, resulting in a loss of comfort.

Therefore, a chair has been proposed in which the backrest is allowed to be bent (twisted) by the pressing force of the seated person. Patent Document 1 relates to a prior application filed by the applicant of the present application, in which a left and right long upper support body is attached to the upper end of a back support so as to rotate horizontally against a spring, and a backrest is provided at both left and right ends of the upper support body. are connected to each other, and when the user's load is biased to either the left or right side, the upper support body rotates horizontally, thereby torsionally deforming the backrest.

JP 2020-58759 A

In Patent Document 1, the backrest bends (twists) due to the pressing force of the seated person, so when the upper half of the body shifts to the right or left and leans against the backrest, the backrest follows and deforms. Therefore, the movement of the seated person's body can be allowed, and the contact with the body can be softened. As a result, comfort can be greatly improved.

There are various types of chair backrests, and a type of backrest with an exposed synthetic resin backrest plate is also widely known. This type of backrest has a simple aesthetic appearance different from that of the cushion type or mesh type. It can be said that there are not many examples of development to chairs that people use for a long time at work, such as office swivel chairs.

However, even if the backrest plate directly supports the body of the seated person, the backrest plate should be made of a material that can be easily deformed, such as an elastomer, or the backrest plate should be perforated with many holes to facilitate elastic deformation. It can also be used as a swivel office chair while maintaining a simple appearance while ensuring high cushioning and fit.

Since the perforations also function as a pattern, by devising the shape of each perforation and the overall arrangement pattern, etc., a high degree of design can be ensured. This point is a unique advantage that cannot be realized with a cushion type backrest or a mesh type backrest. Therefore, chairs with exposed backrests are expected to be used in various fields in the future.

Exposing and using the flexible backrest in this way is beneficial to the user, but the flexible backrest keeps the backrest in tension as manufactured. Since it has to be pre-assembled, there is a risk that it will take time to assemble.

The present invention has been made against such a background, and relates to a chair whose backrest plate is made of a flexible material, and to disclose a structure that can be easily assembled in a state in which the backrest plate is stretched. is.

The present invention has many configurations, typical examples of which are specified in the claims. Among these, the invention of claim 1 relates to a backrest,
"It has a connecting part attached to the support member at the upper part and the lower part, and has a backrest plate made of a soft material that can be flexibly deformed by the pressing force of the seated person,
At least one of the connection portions between the upper portion and the lower portion is provided with a plurality of temporary engagement portions capable of holding the backrest plate in a tensioned state when the backrest plate is attached to the support member,
The connecting portion having the temporary engagement portion is provided in a member that is made of a different material harder than the backrest plate and integrated with the backrest plate.”
It is configured.

The invention of claim 2 is a development example of claim 1,
"The upper and lower portions of the backrest plate are integrally provided with left and right longitudinal reinforcing members made of a hard material by insert molding, and the upper and lower reinforcing members are provided with the left and right connecting portions,
The temporary engagement portion is provided on at least one of the upper and lower reinforcing members."
It is configured.

The invention of claim 3 is a development example of claim 2,
"Each connecting portion of the upper and lower reinforcing members has an engagement structure that fits into the connecting portion of the supporting member,
The connecting portion of one of the upper and lower reinforcing members has a structure to be held by the supporting member by fitting so as not to be detachable,
Of the upper and lower reinforcing members, the connecting portion of the other reinforcing member has the temporary engagement portion and is temporarily fixed to the supporting member and then permanently fixed with screws.”
It is configured.

The invention of claim 4 is a development example of any one of claims 1 to 3,
"The backrest plate has a substantially square shape when viewed from the front, and the upper and lower sides are attached to the support member via the reinforcing member, and it is allowed to be torsionally deformed around the vertical axis. It is done
It is configured.

The invention of claim 5 embodies claim 4,
"The support member is a back frame having a laterally long upper support body, a laterally longitudinal lower support body, and a vertically longitudinal spine support,
The upper side of the backrest plate is connected to the upper support body via the upper reinforcing member,
a lower side portion of the backrest plate is connected to the lower support body via the lower reinforcing member;
The upper support body is attached to the back strut so as to pivot horizontally against elasticity."
It is configured.

The invention of claim 6 embodies claim 5,
"The left and right ends of the backrest plate are attached to the upper support body and the lower support body via the reinforcing members, respectively."
It is configured.

The invention of claim 7 is a development example of any one of claims 1 to 6,
"Each of the connecting parts has a shape of a protrusion or a recess that fits into the connecting part of the supporting member from the front-rear direction."
It is configured.

The invention of claim 8 is directed to a chair,
"Equipped with a backrest and a support member according to any one of claims 1 to 7"
This is the configuration.

In the invention of the present application, the provision of the temporary engaging portion in the connecting portion allows the backrest plate to be removed without the need for the operator to keep pulling the backrest by hand when assembling the chair by attaching the backrest to the support member. The main fixing work such as screwing can be performed while holding the seat in a taut state (a state in which tension is applied) and lifting the hand from the backrest. Therefore, according to the present invention, it is possible to assemble a high-quality chair in which the flexible backrest is held in a taut state while reducing the burden on the worker.

In addition, since the connecting portion of the backrest is provided on the reinforcing member, no local load is applied to the backrest plate. Therefore, even though the chair has a flexible backrest plate, it can maintain high durability and improve its commercial value.

As a method for integrating the backrest plate and the reinforcing member, a molding method using a two-color molding method or adhesion using an adhesive may be used. There is an advantage that the backrest plate and the reinforcing member can be manufactured in a state in which they are firmly joined using a mold device. It also has the advantage of stabilizing the quality.

It is also possible to provide the reinforcing member only at the connecting portion. Therefore, it is possible to prevent excessive deformation of the backrest plate and secure the stability of the seated person.

Each connecting portion can be permanently fixed with a fastener such as a screw. can be reduced to reduce assembly time.

If the backrest plate has the flexibility to be flexed and deformed by the pressing force (body pressure) of the seated person, it swells and deforms so as to wrap the upper half of the body when the seated person leans back, and has high fit and cushioning properties. Further, in the invention of claim 4, when the seated person twists the upper body while leaning against the backrest, the backrest plate can be twisted and deformed to follow the movement of the body, so that the feeling of pressure on the seated person's body is reduced. It is possible to secure a high fit by eliminating the

The seated person may lean against the backrest while leaning the body to the right or left. By doing so, the body can be smoothly tilted backward without discomfort. Therefore, in this case as well, the fit is excellent and comfortable to use.

Various structures can be adopted for the support member, but if a horizontal H-shaped form with support bodies provided above and below the back brace is adopted as in claim 5, the body can be supported by the upper and lower support bodies while maintaining a simple structure. It has the advantage of stable support.

If the left and right ends of the backrest plate are connected to the upper and lower support bodies as in claim 6, the left and right support span of the backrest plate can be maximized. It can be easily transformed to wrap around the body. Therefore, fit can be improved.

Various forms can be adopted for the connecting portion that attaches the backrest to the support member. It can be easily realized by using projections and recesses. In addition, since the connecting portion of the backrest and the connecting portion of the support member are fitted together in the fully fixed state, the fixed state can be firmly maintained even after assembly, which is preferable.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the chair of embodiment, (A) is the perspective view seen from the front, (B) is a side view, (C) is the perspective view seen from the back, (C) is a top view. (A) is a front view with the seat cushion separated, (B) is a perspective view from below, and (C) is a rear view. (A) is a perspective view with the main elements separated, (B) is a side view of only the backrest (indicating the vertical line V in an inclined posture), and (C) is an isolated perspective view seen from below. . (A) is a perspective view of the backrest only, (B) is an isolated perspective view of the back seen from the front, (C) is an isolated perspective view of the back seen from the back, and (D) is the lower reinforcing body. It is a partial perspective view. (A) is a perspective view of the back with the back cover removed, (B) is a perspective view of the back seen from the same direction as (A), and (C) is the center back cover. , and (D) is a front perspective view of the side back cover. It is a figure showing the connection structure of the upper part, (A) is a perspective view of one corner of the backrest as seen from the rear, (B) is a separated perspective view of the backrest and the upper reinforcing member, and (C) is the upper reinforcing member. FIG. 8D is a separated perspective view of an upper support body, and (D) is a separated perspective view of an upper support body and a clip body of the upper reinforcing member; (A) is a front view of the upper portion of the backrest plate, (B) is a cross-sectional view taken along line BB of (A), and (C) is a longitudinal side view of the left and right intermediate portions of the upper end portion of the backrest. It is a figure which shows the structure and connection structure of the lower part of a backrest, (A) is a partial perspective view of a lower reinforcing member, (B) is a separated perspective view of a lower reinforcing member with a lower support body, (C) is the backrest. Partial perspective view, (D) is a partial perspective view of a lower support body. (A) is a flat cross-sectional view of the end cut along line IXA-IXA in FIG. 8(C), and (B) is a flat cross-section of the end cut along line IXB-IXB in FIG. 8(C). FIG. (C) is a plan cross-sectional view of the end portion of the backrest cut at the lowermost hole of the main support portion. (A) is a plan cross-sectional view taken along line XB-XB in FIG. 8(C), (B) is a partial perspective view of the upper reinforcing member as seen from below, and (C) is an end portion of the upper reinforcing member. It is a perspective view. (A) is a side cross-sectional view of the backrest cut at the point of the punched-out hole on the right side of the center line, (B) is an enlarged view of the lower end of (A), and (C) is a communicating hole of the lower reinforcing member. It is a longitudinal side view cut at the point of.

Next, embodiments of the present invention will be described based on the drawings. In the following description, terms such as front, rear, left, and right are used to specify directions, and these directions are specified as seen from a person sitting normally. The front view direction is the direction facing the seated person.

(1).Basic structure of the chair First, the outline of the chair will be explained. The chair of this embodiment is applied to a swivel chair that is frequently used in offices and the like. As shown in FIGS. 1 and 2, the chair comprises, as main members, a seat 1, a backrest 2, a back frame 3 to which the backrest 2 is attached, and leg devices 4. As shown in FIGS. The back frame 3 is an example of a support member.

As can be understood from FIGS. 4A to 4C, the backrest 2 includes a backrest plate 5, an upper reinforcing member 6 overlapping the upper end of the backrest plate 5 from behind, and a lower reinforcing member overlapping the lower portion of the backrest plate 5 from behind. These three parts are integrally joined by an insert molding method. The backrest plate 5 is made of a resin-based soft material such as elastomer, and the reinforcing members 6 and 7 are made of a hard synthetic resin material such as polypropylene or polycarbonate.

On the other hand, the back frame 3 has a back support 8, a left-right long upper support 9 attached to the upper end thereof so as to be able to rotate horizontally, and a left-right long lower support 10 integrally provided at the lower end of the back support 8. , and is generally formed in an H shape as a whole when viewed sideways from the front. An upper reinforcing member 6 of the backrest 2 is connected to the upper support body 9 , and a lower reinforcing member 7 of the backrest 2 is connected to the lower support body 10 . The upper support body 9 horizontally turns against the spring means. Therefore, the torsional deformation of the backrest plate 5 is allowed by the horizontal turning of the upper support member 9 .

As shown in FIG. 1(A), the leg device 4 has a group of branch legs provided with casters. Further, as shown in FIGS. 2B and 3A, a leg strut (gas cylinder) 11 is erected at the center of the leg device 4, and a base body 12 is fixed to the leg strut 11. , the back frame 3 is connected to the base body 12 so as to be tiltable backward. More precisely, as shown in FIG. 3C, the lower end of the back frame 3 is integrally provided with a forward facing portion 3a, and the forward facing portion 3a is fixed to the joint member 13 so that the joint member 13 is It is connected to the base body 12 so as to be tiltable rearward via a left-right longitudinal support shaft 14 (see FIG. 3A).

The support shaft 14 is rotatably held by the base body 12 via a torsion bar as an example of spring means. Therefore, the chair of this embodiment is a reclining chair in which the backrest 2 is tilted backward against the elastic means.

The seat 1 has a structure in which a cushion material is held over an inner shell (not shown) and covered with a skin material, and the inner shell is attached to the outer shell 15 shown in FIGS. 3A and 2B. ing. The outer shell 15 has a structure in which a movable portion 15b is attached to a fixed portion 15a so as to be slidable back and forth. Therefore, when the backrest 2 tilts backward, the seat 1 tilts backward in conjunction with the backrest 2 (synchronizes).

For example, as shown in FIGS. 1(C) and 1(D), the upper support body 9 of the back frame 3 extends from the back support 8 in an arm shape to both the left and right sides, and is recessed forward as a whole when viewed from above (rearward). It has a bulging) arcuate (arcuate) form. On the other hand, the upper reinforcing member 6 forming the upper end of the backrest 2 is slightly recessed forward in plan view, but the degree of the recess is much looser than that of the upper support body 9. Both ends are connected to both left and right ends of the upper support body 9 .

Therefore, a crescent-shaped space is provided between the upper reinforcing member 6 and the upper support member 9 . As described above, the upper reinforcing member 6 of the backrest 2 is made of a synthetic resin such as polypropylene, and due to the existence of the crescent-shaped space, it is allowed to bend and deform slightly so as to bulge backward. However, the degree of deformation is not large.

As shown in FIG. 4(C), upper engaging projections 16 are provided on both left and right ends of the upper reinforcing member 6 to project rearward, while as shown in FIG. An upper engaging recess 17 opens forward in the portion, and an upper engaging protrusion 16 is fitted into the upper engaging recess 17 . The upper engaging projection 16 and the upper engaging recess 17 are examples of the upper connecting portion described in the claims, and will be described later in detail.

As shown in FIGS. 4(B) and 4(C), the lower support body 10 extends from the lower end of the back support 8 in the shape of an arm to both the left and right sides. As a whole, it is greatly curved so as to be dented forward. Therefore, the back frame 3 has a shape similar to an anchor as a whole.

As clearly shown in FIG. 7, the lower end of the backrest 2 is curved to bulge downward when viewed from the front, and is curved to dent forward (bulge backward) when viewed from the bottom. Therefore, the lower reinforcing member 7 is also curved so as to bulge downward (recess upward) in the front view (and rear view), and recess forward (rearward) in plan view (and bottom view). curved.

For example, as can be understood from FIG. 4C, the lower reinforcing member 7 forming the backrest 2 overlaps the lower support body 10 of the back frame 3 over its entire length. As shown in FIG. 4(D), the left and right ends of the lower reinforcing member 7 are provided with lower engaging projections 18 which are block-shaped and narrow backward, while as shown in FIG. Lower engagement recesses 19 into which lower engagement projections 18 are fitted are formed at both left and right ends of the lower support body 10 in the back frame 3, and are inserted into the lower support body 10 from behind toward the lower engagement recesses 19. A screw 24 (see FIG. 3D) is screwed into the boss body 22 to fix the lower reinforcing member 7 (the lower part of the backrest plate 5 ) to the lower support body 10 . The lower engagement projection 18 and the lower engagement recess 19 are examples of the lower connecting portion described in the claims, and the details thereof will be described later.

The back strut 8 and the lower support 10 that make up the back frame 3 are, for example, strength members made of aluminum die-cast (resin molding can also be used), but since many recesses that open backward are formed, The rear surface is covered with a center rear cover 20 and left and right side rear covers 21, as shown in FIG. 4(C). A center rear cover 20 is provided with a boss 22 projecting forward, and the boss 22 is screwed to the lower support body 10.例文帳に追加The side rear cover 21 is fixed to the lower support body 10 using a group of engaging claws 23. - 特許庁An armrest can be attached to the lower support body 10 , and the base of the armrest has the same shape as the side back cover 21 .

For example, as shown in FIG. 11(A), the backrest 2 is curved in a longitudinal side view so that the portion near the lower end protrudes most forward, and the most forward portion becomes the lumbar support portion 26, which is the lumbar support portion. A portion above 26 is a main support portion 27, and a portion below the lumbar support portion 26 is a lower support portion 28. - 特許庁The lumbar support portion 26 has a certain amount of vertical width.

For example, as shown in FIG. 2(A), the backrest 2 (backrest plate 5) is formed so that the boundary between the lumbar support portion 26 and the lower support portion 28 is widest, and the main support portion 27 is formed on the upper side. It is formed in a substantially trapezoidal shape in which the left and right widths are narrowed toward. Therefore, although the backrest 2 (backrest plate 5) is roughly rectangular when viewed from the front, it has a bulging shape as a whole.

Further, when looking at the backrest 2 , in plan view and bottom view, the lower end of the lower support portion 28 forms an arched shape that is greatly recessed forward. The upper end of the main support part 27 is slightly curved and recessed forward from the lower end, and the upper end of the main support part 27 is recessed forward with a gentler curvature than the ridgeline of the lumbar support part 26, but is almost flat.

For example, as shown in FIG. 1A, the backrest plate 5 is formed with holes 29, 30 and 31 in multiple stages and rows. That is, the lumbar support portion 26 is formed with a large number of groups of three-stepped holes 29, the main support portion 27 is formed with a group of six-stepped holes 30, and the lower support portion 28 is formed with two-stepped holes. groups of through holes 31 are formed. Each of the through holes 29, 30, 31 is basically in the form of a vertically long (vertically long) rectangle whose height is greater than its lateral width. Some have non-rectangular shapes due to

For example, as shown in FIGS. 4(A), 4(C) and 9(C), the left and right side portions of the main support portion 27 of the backrest plate 5 are formed into thick side frame portions 32 which are built up in the rearward direction. As a result, the shape retention of the left and right sides of the backrest plate 5 is ensured.

(2). Fixing structure between back plate and upper support body As described above, the upper reinforcing member 6 is integrally joined to the rear surface of the upper end portion of the backrest plate 5 by insert molding. As shown in FIG. 6, the upper reinforcing member 6 has a laterally long shape with a length substantially equal to the lateral width of the upper end of the backrest plate 5, and the above-mentioned upper engaging projections 16 are provided at both the left and right ends. It protrudes backwards.

A portion of the upper reinforcing member 6 excluding the upper engaging projection 16 has a substrate 6a forming a rear surface and first and second laterally elongated rib plates 6b and 6c projecting forward from the substrate 6a. A large number of reference small chambers 36 are formed by partitioning a space surrounded by the substrate 6a and the upper and lower horizontally long rib plates 6b and 6c with a large number of vertically long rib plates 35. As shown in FIG.

Further, as shown in FIG. 6(C), a portion of the upper reinforcing member 6 near the upper engaging projection 16 has a lower frame continuous with the upper engaging projection 16, the second horizontally elongated rib plate 6c, and the substrate 6a. A portion 37 is formed, and a portion surrounded by the lower frame portion 37 serves as a side chamber 38 .

As shown in FIGS. 7B and 7C, an upper thick portion 39 integrally joined to the upper reinforcing member 6 is formed at the upper end portion of the backrest plate 5. are inserted into the small chambers 37 and 38 of the upper reinforcing member 6, and the upper and lower thick rib plates 6b and 6c are embedded in the upper thick portion 39. As shown in FIG. Then, as shown in FIG. 10B, a large number of first anchor holes 40 opening the reference chamber 36 downward are formed in the second lateral rib plate 6c, and the upper thick portion 39 is formed in the first anchor holes 40. As shown in FIG. is letting in.

Therefore, the portion of the upper thick portion 39 that fills each of the reference chambers 37 and the portion positioned under the second laterally elongated rib plate 6c are connected at the first anchor hole 40, and a high anchor effect is provided to the backrest. The bonding strength between the plate 5 and the upper reinforcing member 6 is increased. Note that the first anchor hole 40 extends to the substrate 6a.

As shown in FIGS. 7B and 7C, the upper thick portion 39 of the backrest plate 5 has a holding portion 39a that wraps around the back side of the upper portion of the upper reinforcing member 6. However, as shown in FIG. As shown, the substrate 6a of the upper reinforcing member 6 is formed with a large number of second anchors 41 that are open in the front and rear directions to connect the base of the upper thick portion 39 and the holding portion 39a. Therefore, even if a person tries to roll up the holding portion 39a, the holding portion 39a is kept joined to the upper reinforcing member 6 without being rolled up.

As shown in FIG. 6(B), on both left and right ends of the upper reinforcing member 6, roughly rectangular upper boss portions 42 protrude rearward and downward. A protrusion 16 protrudes. The upper boss portion 42 has a recess that opens forward, and this forward recess is filled with the upper thick portion 39 of the backrest plate 5 .

As shown in FIG. 6(B), the upper corner of the backrest plate 5 is formed with an enclosing frame 43 that encloses the upper boss 42 of the upper reinforcing member 6 from above, below and from the outside. The rear surface of 43 overlaps the front surface of upper support body 9 . Further, as can be understood from FIG. 6A, the rear surface of the surrounding frame portion 43 of the backrest plate 5 and the rear surface of the upper boss portion 42 of the upper reinforcing member 6 are flush with each other.

As can be accurately understood from FIG. 10(C), the upper boss portion 42 of the upper reinforcing member 6 has, as the upper engaging projection 16, a frame-shaped positioning projection frame 44 opened downward and a downward hook-shaped engaging claw. 45 are projected backward. The positioning projection frame 44 has left and right side plates and an upper plate, and has a substantially H-shaped configuration when viewed from the rear.

As shown in FIGS. 6(C) and 6(D), the upper support member 9 has a gutter-shaped basic structure that opens forward, and a group of reinforcing ribs 47 are arranged inside. Upper engaging recesses 17 partitioned by end ribs 48 are formed at both left and right ends. A recessed portion 49 for equalizing thickness is formed on the outer side of the upper engaging recess 17, and a pocket portion for forming an engaging hole 50 below the upper engaging recess 17. 51 is formed.

The pocket portion 51 is opened forward and slopes upward toward the rear. That is, since it is not possible to open the engaging hole 50 below the upper reinforcing member 6 from the point of view of aesthetics, by providing the pocket portion 51 in an inclined posture, the upper engaging recess 17 can be removed from the mold. An engagement hole 50 is formed in the bottom plate of the.

The positioning projection frame 44 of the upper reinforcing member 6 is set to a size that is tightly fitted into the upper engaging recess 17 of the upper support body 9 and does not move up, down, left, right, or forward or backward. The engaging claw 45 is formed at the lower end inside the positioning projection frame 44 . The tip of the engaging claw 45 is an upward inclined surface 45a, and when the positioning projection frame 44 is pushed into the upper engaging recess 17 of the upper support body 9, the engaging claw 45 is once deformed to rise upward. Then, the hook is deformed back and fitted into the engaging hole 50.例文帳に追加As a result, the upper reinforcing member 6 (and the upper end portion of the backrest 2) is held by the upper support member 9 in a non-separable manner.

Furthermore, the end rib 48 constituting the upper engaging recess 17 is formed with a cut-out groove 52 opening forward, and as shown in FIGS. The claw portion 53a is inserted. The clip body 53 has a base portion 53b located inside the end rib 48, and the claw portion 53a can be inserted into the cut-open groove 52 by pushing the base portion 53b in the laterally outward direction with a fingertip.

Although not shown, the inner plate of the positioning projection frame 44 in the upper reinforcing member 6 has a watermark hole through which the claw portion 53a of the clip body 53 penetrates (the inner plate of the positioning projection frame 44 is opened by the claw portion 53a). It is also possible to break through.)

The claw portion 53a of the clip body 53 is bent in a lateral U-shape, and once elastically deformed, it enters the cut-open groove 52, and when it completely enters the cut-open groove 52, the U-shaped bent tip surface comes off the cut-open groove 52 and ends ribs. 48 , and thereby the clip body 53 is in a state where it cannot be removed from the cut-open groove 52 .

With the clip body 53 attached to the cut-open groove 52 , the claw portion 53 a of the clip body 53 overlaps the upper surface of the engaging claw 45 of the upper reinforcing member 6 . Therefore, the engaging claw 45 of the upper reinforcing member 6 is held by the clip body 53 so as not to move upward. The inward projection 46 of the positioning projection frame 44 abuts or comes into close contact with the claw portion 53a of the clip body 53 from the front. Therefore, the clip body 53 is held so as not to come off forward.

As shown in FIGS. 6(C) and 6(D), an inverted concave space 54 is formed adjacent to the space in the upper support body 9 in which the base portion 53b of the clip body 53 is inserted. is provided with a hole 54a for mounting a headrest (not shown).

(3) Structure for insert molding As shown in FIG. 7(A), a group of upper dummy recesses 55 are formed in the upper end of the front surface of the backrest plate 5 so as to be continuous with the uppermost punched hole 30 . there is 1(A) and 4(B), a group of side dummy recesses 56 are formed on the left and right sides of the front surface of the backrest plate 5, as indicated by hatched lines in FIGS. , and a lower dummy recess (not shown) is formed in the lower side of the front surface of the backrest plate 5 . The side dummy recesses 56 and the lower dummy recesses include those independent from the through holes 29 and 30 and those continuous with the through holes 29 and 30 .

Since the upper reinforcing member 6 is integrally joined to the upper end portion of the backrest plate 5 from the back side, the upper reinforcing member 6 requires an upper thick portion 39, and the upper thick portion 39 is provided with an upper hole 30. Although it cannot be formed, in this embodiment, an upper dummy recess 55 is formed in the front surface of the upper thick portion 39 so as to be continuous with the uppermost upper punched hole 30 , and the upper end of the recess is positioned near the upper end of the backrest plate 5 . By doing so, the appearance as if the upper hole 30 were extended to the vicinity of the upper end of the backrest plate 5 is maintained, and both beauty and strength are achieved.

As described with reference to FIGS. 4(A), 4(C) and 9(C), the left and right sides of the backrest plate 5 are provided with thick side frame portions 32. The side frame portions 32 are Although it has a certain amount of lateral width, the side dummy recesses 56 already described are formed in the front surface of the side frame portion 32 . The lower side of the backrest plate 5 is the same, and a lower dummy recess positioned near the lower side of the backrest plate 5 is formed in a portion overlapping the lower support body 10 .

By forming the dummy recesses 55 and 56 along the entire circumference of the backrest plate 5 in this manner, the groups of the through holes 29, 30 and 31 appear to extend over the entire front surface of the backrest plate 5. , to achieve design uniformity. As a result, the backrest plate 5 retains the required strength while ensuring a beautiful appearance.

As shown in FIGS. 7A and 7B, the upper end of each upper dummy recess 55 communicates with a through hole 57 that opens forward and backward. As shown in FIGS. 7B, 7C and 11A, the through hole 57 is formed by insert-molding the backrest plate 5 into the upper reinforcing member 6 using a pair of metal molds 58 and 59 that are in close contact and apart. It is formed in order to firmly press and fix the upper reinforcing member 6 with a pair of molds 58 and 59 when doing so.

That is, as shown in FIGS. 7B and 7C, the upper reinforcing member 6 includes a substrate 6a and a first oblong rib positioned at the height of the upper end of the upper punched hole 30 and protruding forward from the substrate 6a. While supporting the substrate 6a with one mold 58, the first rib of the upper reinforcing member 6 is formed in the other mold 59 so as to be continuous with the portion forming the upper dummy recess 55. A protrusion is formed to hold down the plate 6b, and a through hole 57 appears at a portion where the protrusion is removed after molding.

The upper reinforcing member 6 is laterally elongated and thin, and the upper thick part 39 of the backrest plate 5 overlaps on both the left and right ends, so that the left and right ends of the upper reinforcing member 6 are pressed by a pair of molds 58 and 59. Therefore, if the upper reinforcing member 6 is simply superimposed on one of the molds 58, there is a risk that lifting will occur during molding and the resin will flow to the back side of the substrate 5a. On the other hand, if the upper reinforcing member 6 is held by a pair of molds 58 and 59 as in the present embodiment, floating can be prevented and molding can be performed with high precision.

Therefore, although the through holes 57 are the result of a technique for forming accurately, a group of the through holes 57 scattered on the upper end of the backrest plate 5 can be visually recognized by a person, so the pattern is accentuated by the person. It also has an aesthetic effect that draws the attention of This point is one of the advantages of this embodiment.

(4) Structure of the lower portion of the backrest As shown in FIGS. ) and FIG. 8(A), the lower reinforcing member 7 has a channel-like shape that opens rearward, and the interior thereof is divided into a large number by a horizontally elongated rib 61 and a large number of vertically elongated ribs 62 . is divided into small chambers 63 of .

A plurality of third anchor holes 64 are formed in the front plate (bottom portion) of each small chamber 63 , and the resin of the backrest plate 5 flows into the small chamber 63 through the third anchor holes 64 . Therefore, as clearly shown in FIG. 11(C), the lower overlapped portion 5b of the backrest plate 5 is connected to the anchor portion 5c that fills the small chamber 63 of the lower reinforcing member 7. As shown in FIG. Therefore, the lower side of the backrest plate 5 is firmly joined to the lower reinforcing member 7 .

The anchor portion 5c is exposed rearward (see, for example, FIG. 8(C)). As clearly shown in FIGS. 11B and 11C, the upper surface of the lower reinforcing member 7 is also exposed. The exposed portion of the lower reinforcing member 7 is in close contact with one mold 58 during insert molding.

Since the upper reinforcing member 6 is set to allow a slight bending deformation when used as a chair, it is held down by a pair of molds 58 and 59 so as to perform insert molding accurately. 7 has high rigidity without assuming elastic deformation. In addition, since it is curved when viewed from the front and from the top, the resin does not flow around due to bending deformation during molding. Furthermore, it can be fixed to one of the molds 58 using the screws 24 already described. Therefore, there is no need to press the lower reinforcing member 7 with the other mold 59 during molding, and therefore no through-holes are formed due to molding.

For example, as shown in FIGS. 8(A), 8(B) and 8(C), lower engaging projections 18 in the form of truncated quadrangular pyramids are provided at both left and right end portions of the lower reinforcing member 7, while FIG. As shown in (B) and (D), the lower engaging recesses 19 into which the lower engaging projections 18 are fitted are provided at the distal end portions of the left and right lower support bodies 10 . A screw 24 inserted from the rear is screwed into a nut 67 built in the lower engaging projection 18 . Since the lower engagement projection 18 and the lower engagement recess 19 are tapered, the four surfaces are brought into close contact with each other by screwing in the screws 24, and are firmly fixed without rattling.

As shown in FIGS. 8(A) to 8(C), the lower engaging projection 18 has a square pyramid shape, so that the upper engaging projection 16 has an inward side surface 18a. , the lower engaging recess 19 has an outwardly facing inner side surface 19a on which the inwardly facing side surface 18a overlaps when the lower engaging projection 18 is fitted from the front. As shown in FIG. 9A, the inward side surface 18a of the lower engaging projection 18 contacts the outward inner side surface 19a of the lower engaging recess 19 from the outside in the left-right direction.

Therefore, when assembling the chair, the lower support member 10 is slightly stretched in the left-right direction against its elasticity, and tension is applied to the backrest plate 5 in the left-right direction. When fitted into the right and left lower engaging recesses 19 of the body 10 from the front, the lower reinforcing member 7 is caught by the inward side surface 18a and the outward inner side surface 19a. temporarily held in the state attached to the Therefore, the screw 24 can be screwed in easily.

Therefore, in the present embodiment, the inward side surface 18a of the lower engagement projection 18 and the outward inner side surface 19a of the lower engagement recess 19 form a temporary engagement portion. Alternatively, it can be said that the lower engaging projection 18 and the lower engaging recess 19 constitute a temporary engaging portion. When the lower engaging projection 18 is temporarily engaged with the lower engaging recess 19, a weakening gap is formed between the tip surface of the lower engaging projection 18 and the bottom surface of the lower engaging recess 19. Both are tightly fitted by screwing the screws 24 .

As shown in FIGS. 8B and 8C, the outer surface of the lower engaging projection 18 is provided with an auxiliary projection 69 facing outward, while the lower engaging recess 69 is provided as shown in FIG. 8B. 19 is provided with an auxiliary engaging hole 70 into which the auxiliary projection 69 is fitted.

Since the backrest plate 5 is stretched in the lateral direction, it is temporarily held by the lower reinforcing member 7, and when it tries to return to its original position, the lower engaging projection 18 is pushed back as indicated by the arrow 71 in FIG. 9(A). However, as can be seen from FIG. 10(A), the auxiliary projection 69 is caught in the auxiliary engagement hole 70 and returns to its original position due to the elastic restoring force. can be prevented.

As shown in FIGS. 8B and 8C, the lower engaging projection 18 has a bag portion 68 that holds the nut 67 so that it cannot rotate. A portion 72 opens outward while communicating with the bag portion 68 . When the backrest plate 5 is insert-molded, a dummy nut (not shown) that fits into the dummy space 72 and the bag portion 68 is attached, and a screw inserted through one of the molds 58 is screwed into the dummy nut. , the lower reinforcing member 7 can be firmly fixed to one of the molds. Since the resin does not flow into the portion of the dummy nut, a dummy space 72 is formed to allow the screw 24 to be screwed.

Although it is preferable to apply tension to the backrest plate 5 in the vertical direction as well, it is structurally difficult to strongly stretch the backrest plate 5 in the vertical direction. It is rational to pull in using the tapered surface of the engaging recess 19 .

For example, as shown in FIGS. 8A and 8B, upward projecting portions 7a extending to the sides of the lumbar support portion 26 are provided at both left and right ends of the lower reinforcing member 7 . For example, as can be understood from FIGS. 1A and 1C, the upward projecting portion 7a supports the lateral portion of the lumbar support portion 26 of the backrest plate 5. As shown in FIG. Therefore, even if the pressing force of the seated person acts on the lumbar support portion 26, the lumbar support portion 26 will not be excessively deformed. That is, the lumbar support portion 26 is firmly supported at both left and right ends by the upwardly projecting portion 7a.

As shown in FIG. 8(B), the portion of the lower reinforcing member 7 where the lower engaging projection 18 is provided is a slightly stepped recess 73, and as shown in FIG. 8(D), the lower support The body 10 is provided with a rib 74 that fits into the recess 73 of the lower reinforcing member 7 (see also FIG. 10(A)).

In the present embodiment, the upper connecting portion alone is non-separably held by the upper support body, and the lower connecting portion is temporarily provided with the engaging portion, but the relationship may be reversed. In the case of reversing, the lower connecting portion is connected first, and the upper connecting portion is connected later and fixed with screws. It is also possible to provide temporary engaging portions in the upper and lower connecting portions.

Although the backrest of the embodiment is generally rectangular, it may be circular or elliptical. In the case of a quadrangle, it is also possible to form a trapezoid in which the lateral width decreases toward the bottom. As the temporary engaging portion, it is also possible to form a projection on the inward side surface of the engaging projection and form an engaging hole on the inner surface of the engaging recess. Alternatively, it is possible to form an engaging recess on the inward side surface of the engaging projection and form the engaging projection on the inner surface of the engaging recess.

Although the back frame is used as the support member for the backrest in the embodiment, a shell-like structure can also be used. When adopting a back frame, a square shape having left and right side members can also be adopted.

The present invention can be embodied in the back of a chair. Therefore, it can be used industrially.

2 backrest 3 back frame as an example of a support member 5 backrest plate 6 upper reinforcing member 7 lower reinforcing member 7a upward projecting portion 8 back strut 9 upper support body 10 lower support body 16 upper engagement projection constituting an upper connecting portion 17 upper Upper engaging recess 18 forming the connecting portion Lower engaging protrusion 18a forming the lower connecting portion Inward side surface 19a forming the temporary engagement portion Outward inner side surface forming the temporary engagement portion 24 Screw 39 Upper thickness Part 44 Positioning projection frame constituting upper engaging projection 45 Engaging claw for upper engaging projection 67 Nut 69 Auxiliary projection 70 Auxiliary engaging hole

Claims (8)

The backrest plate has a connecting part attached to the support member at the upper part and the lower part, and is made of a soft material that can be flexibly deformed by the pressing force of the seated person,
At least one of the connection portions between the upper portion and the lower portion is provided with a plurality of temporary engagement portions capable of holding the backrest plate in a tensioned state when the backrest plate is attached to the support member,
The connecting portion having the temporary engagement portion is provided in a member made of a different material harder than the backrest plate and integrated with the backrest plate,
the back of the chair. Left and right longitudinal reinforcing members made of a hard material are integrally provided at the upper and lower portions of the backrest plate by insert molding, and the upper and lower reinforcing members are provided with the left and right connecting portions,
The temporary engagement portion is provided on at least one of the upper and lower reinforcing members,
A chair back as claimed in claim 1. Each connecting portion of the upper and lower reinforcing members has an engagement structure that fits into the connecting portion of the support member,
The connecting portion of one of the upper and lower reinforcing members has a structure to be held by the supporting member by fitting so as not to be detachable,
The connecting portion of the other reinforcing member of the upper and lower reinforcing members is temporarily fixed to the supporting member by having the temporary engagement portion, and then permanently fixed with a screw.
A chair backrest as claimed in claim 2. The backrest plate has a substantially rectangular shape when viewed from the front, and the upper side and the lower side are attached to the support member via the reinforcing member, and are allowed to be torsionally deformed around the vertical axis. ing,
A chair backrest according to any one of claims 1 to 3. The support member is a back frame having a left-right long upper support body, a left-right long lower support body, and a vertically long spine support,
The upper side of the backrest plate is connected to the upper support body via the upper reinforcing member,
a lower side portion of the backrest plate is connected to the lower support body via the lower reinforcing member;
wherein the upper support body is attached to the back brace so as to rotate horizontally against elasticity;
A chair backrest as claimed in claim 4. Left and right ends of the backrest plate are attached to the upper support body and the lower support body via the reinforcing members, respectively.
A chair backrest as claimed in claim 5. Each connecting portion has a shape of a protrusion or a recess that fits in the front-rear direction with respect to the connecting portion of the support member,
A chair backrest according to any one of claims 1-6. A chair comprising a backrest and a support member according to any of claims 1-7.

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