JP5467814B2 - Chair back or seat - Google Patents

Description

  The present invention relates to a chair backrest and / or seat. More precisely, the present invention relates to a backrest or seat having a synthetic resin support body (back plate or seat plate).

  The structure of the chair back and seat varies greatly. For example, in the case of a swivel chair frequently used for office work, a synthetic resin inner shell (back plate, seat plate) is used, and a cushion is placed on the front. Often timber. And as a means for improving cushioning properties and fitting properties, it has been proposed or implemented to form a structure in which a support body such as an inner shell is easily deformed by the body pressure of a seated person.

  For example, Patent Document 1 relating to the application of the present applicant discloses that a large number of slit groups are formed in the inner shell to facilitate elongation deformation, and also a patent related to the applicant's application. Document 2 discloses that a group of strips crossed in a net-like manner is integrally formed on a frame constituting the outer peripheral portion of a seat or a backrest, and the support portion is greatly sunk and deformed by extension deformation of the strips. .

JP 2000-93250 A JP 2005-160558 A

  Now, in the back of the chair, there is a structure in which left and right horizontally long slits are formed in multiple stages in the inner shell and the horizontally long support plates are arranged in multiple stages. This type is not only excellent in air permeability, but also has an advantage that it can be applied to, for example, a type in which a mesh material (net material) is stretched because there is no sense of incongruity even if the form can be visually recognized.

Conventionally, however, each horizontally long support plate has a simple band plate shape and is merely a loosely curved shape in a backward-facing concave shape in plan view, so that it can be elastically deformed so that it is greatly retracted backward by the body pressure of the seated person. Therefore, it was difficult to ensure high cushioning and fit. Regarding this point, it is conceivable to form a thin hinge part at the base of each horizontally long support plate, but this hinge system not only reduces the durability due to concentration of the load accompanying locking on the hinge part, for oblong support plate to bend sharply at the location of the hinge, the problem of poor fit is a concern without'll mimic the horizontal support plate of the human body.

  The present invention has been made in view of such a current situation, and is intended to ensure high cushioning and fit in a backrest or seat having a support body composed of a group of horizontally long support plates.

The invention according to claim 1 is directed to a backrest or a seat, and the backrest or the seat according to the present invention includes a support body that receives the body pressure of a seated person, and the support body includes right and left sides of the support body. The left and right side members extending in the vertical direction to form both sides, and a plurality of horizontally long support plates arranged in multiple stages between the left and right side members, the support body is integrally formed of synthetic resin The left and right side members and the horizontally long support plate group are connected in series.

  And in this basic configuration, a deformation that makes it easy for the horizontally long support plate to bend and deform so that it moves backward due to the body pressure of the seated person in at least a part of the lateral support base portion of the group of the horizontally long support plates. The facilitating buffer portion is formed in a state of spreading in the left-right direction so as to extend inward from the base portion of the horizontally long support plate so as to bend and deform into a curved state in plan view due to the body pressure of the seated person .

  The invention according to claim 2 is the embodiment of the invention according to claim 1 in the backrest. In claim 1, in the vicinity of the left and right roots of the horizontally long support plate, the vertical width dimension of the horizontally long support plate is larger than that of other parts. A narrow portion which is substantially narrow is formed, and this narrow portion constitutes the deformation facilitating buffer portion.

The invention of claim 3 embodies the invention of claim 2, and in the vicinity of the base of the horizontally long support plate, an upper slit that opens upward in a lateral L shape and a lower slit that opens upward in a lateral L shape forms the door, forms a width narrower portion by the vertical slit, and the portion surrounded by at the slit has become a Horizontal lip, joint an oblong lip oblong support plate adjacent the upper and lower It is connected with.

  The invention of claim 4 constitutes the subordinate concept of claims 1 to 3, and at the upper end edge or lower end edge or both upper and lower end edges of the horizontally long support plate, a horizontally long rib extending rearward and extending in the left-right direction is formed. The rearwardly projecting dimension of the laterally long rib is made lower in the vicinity of the base portion of the laterally long support plate to form the deformation facilitating buffer portion.

  Specifically embodying claims 1 to 4 of claim 5, the base portion of the horizontally long support plate is a bulging portion that protrudes in front of the side member in a state of being curved in a convex shape in a plan view. This bulge portion is formed as the deformation facilitating buffer portion. In addition, although Claims 2 to 5 are embodied in the backrest, the specific matters described herein can also be applied to the seat (when Claim 4 is applied to the seat, the horizontally long rib is the bottom surface of the horizontally long support plate). Will be provided).

  According to the first aspect of the present invention, since the easy-to-deform buffer portion is formed near the left and right roots of the horizontally long support plate, the horizontally long support plate is easily bent and deformed by the body pressure of the seated person. Therefore, high cushioning properties can be ensured. And since the deformation | transformation facilitation buffer part of this invention has the breadth of the left-right direction, while preventing stress concentration, high durability can be ensured and fitting property can also be improved by gentle bending. After all, according to the present invention, it can be said that a seat or a backrest excellent in cushioning and fitting properties can be provided in a state in which durability is ensured.

Deformation facilitating buffer unit variously be embodied as claims 2 to 5 (these may alone, but preferably used in combination.). And if a narrow part is employ | adopted like Claim 2, there exists an advantage by which bending strength can be made low more reliably. Further, it is preferable to connect the horizontally long support plates adjacent to each other by a joint so as not to be separated excessively at the time of rocking. Because it is possible to allow the gap between the upper and lower horizontal support plates to be widened, it is possible to prevent the horizontal support plates adjacent to each other from being excessively widened while ensuring the freedom of bending deformation of each horizontal support plate. There is.

  Now, in order to accurately support the human body from behind, it is preferable that the horizontally long support plate has a certain degree of shape retention. In other words, it is preferable to support the seated person's waist and the back of the back as evenly as possible. In other words, it is preferable to take into consideration that as much body pressure as possible acts on the horizontally long support plate. In this respect, if the horizontally long support plate is formed with the horizontally long ribs as in claim 4, the horizontally long support plate can be maintained with appropriate rigidity, so that the cushioning / fitness and body stability are balanced and more comfortable. You can get a good feeling of drowning. You may form a rib in a jump.

  When the bulging part is adopted as the deformation facilitating buffer part as in claim 5, the laterally long support plate tends to move backward as a whole because the bulging part is bent and deformed so as to fall back. It can be said that the fit is even better.

It is an external view of the chair which concerns on 1st Embodiment, (A) is a front view, (B) is a side view. It is a perspective view of a chair. (A) is a side view showing the movement of rocking, (B) is a separated side view of the backrest. It is the perspective view which looked at the chair from back. It is a separate perspective view, (A) is the figure seen from the front, (B) is the figure seen from the back. (A) is a partially broken front view of a backplate , (B) is the elements on larger scale of (A). It is a partially broken rear view of a back plate . It is a top view. It is a fractured perspective view of a backrest. (A) is a perspective view of the lower part of the back plate , (B) is a cross-sectional view taken along the line XB-XB of FIG. 7, (C) is a partial plan sectional view of the lower part of the back plate 8, and (D) is a cross-sectional view of FIG. It is XD-XD view sectional drawing. It is the fragmentary perspective view which turned the back plate over and arranged with the back frame. It is the elements on larger scale of FIG. It is the elements on larger scale of FIG. It is a separation perspective view showing a locking mechanism. It is a figure which shows other embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings. The present invention is applied to a swivel chair that is variously used for office work. While using the wording of the front and rear left and right to identify the direction in the following description, which is based on the person who seated normally wear chair defines the direction in which the seat occupant facing as before. The front view direction is a direction opposite to the seated person, and the rear view direction is a direction when the seated person is viewed from behind.

(1). Outline of chair As shown in FIGS. 1 and 2, the chair is a leg device displaying only the leg strut (gas cylinder) 1, the base 3 fixed to the state of the leg strut 1, and disposed above the base 3. The seat 4 has a backrest 5 disposed behind the seat 4. An armrest device 6 as an optional item can be attached to the base 3. 1 and 2, only one of the armrest devices 6 is displayed, but a pair of left and right is attached. The leg device, such as those from the central cylinder with casters branch rod of five extend radially, various types can be used.

The backrest 5, a back frame 7, which is linked to the rear tilt the base 3, and a back plate 8 (inner shell) 8 attached to the front surface of the back frame 7 has a strength member, the cushion body to the front surface of the back plate 8 9 (the cushion body 9 is not shown in FIG. 1B or FIG. 2). The front surface of the cushion body 9 is covered with a skin material 10 such as a cloth. As shown in FIGS. 9 and 10B, the skin material 10 is configured in a bag shape, and the cushion body 9 and the back plate 8 is covered with a bag-shaped skin material 10. Therefore, the entire back plate 8 is not exposed, and a person cannot visually recognize it from the outside.

In order to clarify the structure, the cushion body 9 and the skin material 10 are omitted in many of the drawings. Or attaching it to the back frame 7 back plate 8 covers only a bag made of mesh, the back plate 8 without mounting a cushion body 9 or a mesh material in the exposed, to support the body directly in the back plate 8 Is also possible. Furthermore, it is also possible to expose a rear surface of the back plate 8 by applying a decorative sheet made of mesh or the like that can be seen through only to the front surface of the back plate 8. In this case, the form of the back plate 8 can be seen through from the front.

  The chair of the present embodiment is a rocking type in which the backrest 5 tilts backward. As shown by a one-dot chain line in FIG. 3, when the seated person leans on the backrest 5, the seat 4 moves up while being lifted by a certain size. In other words, the weight of the seated person acts as a resistance against the backward tilting of the backrest 5, and when the seat 4 returns to its original position by the weight of the seated person, the force and the moment caused by the seated person bending the upper body back are balanced. Thus, a locked state can be obtained.

An elastic body that provides resistance to locking is built in the base 3. Therefore, to be precise, the locking is performed against the elastic restoring force of the elastic body and the load of the seated person. Since a part of the body weight of the seated person acts so as to return the backrest 5, the elastic body used for rocking need only have a weak elastic restoring force. The locking mechanism to be described later, illustrating the backrest 5 first.

(2) Basic structure of the back frame As shown in FIGS. 5 and 14, the back frame 7 is composed of a vertically long left and right side frame 12 constituting the left and right side portions thereof and a horizontally long shape connected to the upper ends of the left and right side frames 12. the upper frame 13 has right and left longitudinal lower frames 14 connected to the lower end of the left and right side frames 12, are I Do with opened frame shape back and forth substantially rectangular as a whole. Further, side arms 15 that extend forward toward the left and right outer surfaces of the base 3 are integrally formed at the lower ends of the left and right side frames 12, and a front gate-type front member 16 is integrally formed with the left and right side arms 15. It is connected.

The back frame 7 uses a molded product made of a synthetic resin such as polypropylene, but an aluminum die-cast product can also be adopted. Further, for example, the side arm 15 may be constituted by a plurality of members such as a separate member. For example, as clearly shown in FIG. 8, the upper frame 13 of the back frame 7 is formed in a state of opening largely forward in plan view so that the back plate 8 is attached only to the left and right side portions thereof. In other words, a horizontally long hole is formed between the upper frame 13 and the back plate 8 of the back frame 7. For this reason, a person can not only be gripped by the upper frame 13 of the back frame 7 but also the upper end portion of the back plate 8 can be elastically deformed.

As clearly shown in FIG. 1 (B) and FIG. 3 (A), the side frame 12 of the back frame 7 is viewed from the side so that the portion slightly higher than the waist of the seated person is in front. It is bent in a forward projecting shape. In other words , the side frame 12 of the back frame 7 is bent in a dogleg shape in a side view, and thus the side frame 12 has a vertex portion 17. The back plate 8 is not attached to the back frame 7 at a portion below the apex portion 17 of the back frame 7 and is in a cantilever state. Alternatively, a portion of the back plate 8 below the apex portion 17 of the back frame 7 is overhanging.

  Further, the side frame 12 of the back frame 7 is in a neutral state where the seated person is not leaning, a portion above the apex portion 17 is in a backward tilted posture, and a portion below the apex portion 17 is in a forward tilted posture. ing. The angle at which the portion below the apex portion 17 tilts forward with respect to the vertical line is slightly larger than the angle at which the portion above the apex portion 17 tilts backward with respect to the vertical line. The upper frame 13 and the lower frame 14 are gently curved in a forward concave shape in a plan view.

(3). Basic structure of the back plate 8 The back plate 8 is a molded product made of synthetic resin such as polypropylene, and is integrally connected between the upper and lower side members 19 and the upper ends of the side members 19. The upper member 20 and the lower member 21 integrally connected to the lower ends of the left and right side members 19 form a substantially rectangular outer shape, and further, a horizontally long support plate 22 connected to the left and right side members 19 is multi-staged therein. Is arranged. For example, as clearly shown in FIG. 10D, the front surface of the side member 19 has a curved surface that shifts backward as it goes outward from the inner side to which the horizontally long support plate 22 is attached.

  For example, as shown in FIG. 6 and FIG. 10D, between the horizontally long support plates 22 adjacent to each other in the vertical direction, between the horizontally long upper support plate 22 and the upper member 20, and at the bottom most horizontally long support plate 22. Between the lower member 21 and the lower member 21, a horizontally long space 23 is vacant. Each of the horizontally long support plates 22 basically has the appearance of a horizontally long strip having a uniform width, and the wide surface faces forward and backward.

  For example, as shown in FIG. 10D, a fillet 22 that is curved in plan view is formed on the back surface of the base of the horizontally long support plate 22. This prevents stress from concentrating on the base of the horizontally long support plate 22 and allows the horizontally long support plate 22 to bend and deform within a certain range near the root.

For example, as described with reference to FIGS. 1B and 3A, the back plate 8 is in a cantilever state with respect to the back frame 7 at a portion below the apex portion 17 of the back frame 7. In other words, the back plate 8 has an overhang portion 8a below the apex portion 17 of the back frame 7, but the back plate 8 is slightly smaller than the apex portion 17 of the back frame 7. It is bent in a forward projecting shape in side view so that the lower part is the foremost. In other words, the back plate 8 has a lumbar support portion 8b for supporting accurately portions of the waist of the seated person, moreover, since the lumbar support portion 8b is provided on the overhang portion 8a, the back plate 8 lumbar support section 8b can be elastically deformed to move backward.

As shown in FIGS. 8 and 10, the front surface of the back plate 8 is concave (curved) in a forward-facing concave shape with a very gentle curvature, and the degree of the concave is the largest in the lumbar support portion 8b. The support plate 22 is almost flat. This is mainly aimed at the visual effect of giving a favorable impression to the person by making it look like wrapping the body, but the waist part of the person has a roundness in plan view and the back is There is also an aspect that corresponds to the physical characteristics of being almost flat. It is also possible to form each horizontally long support plate 22 in a linear shape in plan view.

Each of the horizontally long support plates 22 has an appearance of a band plate. For example, as shown in FIG. 6, the left and right base portions of the horizontally long support plates 22 adjacent to each other are connected by a joint 24 that vertically traverses the space 23. ing. Further, the joints 24 adjacent to each other in the vertical direction are alternately displaced in the left and right directions, and the substantially long L-shaped inward slits 25 are provided so that the joints 24 are sandwiched from the upper and lower sides of the respective horizontally long support plates 22. And the outward slit 26 are formed. The inward slit 25 extends inward toward the longitudinal center line of the back plate 8 , and the outward slit 26 extends outward toward the outer edge of the backrest 5.

Although joint 24 adjacent vertically are shifted to the right and left alternately, the location of the joint 24 which is offset, such as by vertical center line of the back plate 8 are vertically inward slit 25 is formed, the back plate 8 The upper and lower outward slits 26 are formed at the joint 24 that is shifted so as to be closer to the outer edge of the outer support. Therefore, an inward slit 25 and an outward slit 26 are formed in one horizontally long support plate 22. As a result, each of the horizontally long support plates 22 has a posture in which the horizontal support plate 22 protrudes sideways from the side member 19 and then rises or falls by a small dimension , and then returns to the lateral direction. A stepped narrow portion 27 is formed.

  Further, the inward slit 25 and the outward slit 26 are synonymous with the upper slit and the lower slit described in the claims, respectively, and the slits 25 and 26 are opened to the upper end surface or the lower end surface of the horizontally long support plate 22. Accordingly, a horizontally long lip 24 ′ is formed at the narrow portion 27, and the horizontally long lips 24 ′ adjacent to each other in the vertical direction are connected by the joint 24.

The narrow portion 27 is an example of the deformation facilitating buffer portion described in the claims, and is narrower than other portions, so that it is easily bent and deformed by sitting. Although Horizontal support plate 22 is basically an appearance of equal width over the left and right full length, for receiving a body pressure of a seated person at the location of the slits 25 and 26 is essentially located at a point Habasema 27 therefore Horizontal support plate 22 is equal to which is substantially narrower at a point Habasema portion 27. In this sense, the term “substantially” is used in this sense.

For example, FIGS. 10B and 10C show a state in which a bulging portion 22a is formed near the base of the horizontally long support plate 22 as another example of the deformation facilitating buffer portion. That is, the bulging portion 22a is bent forwardly in a plan view so as to protrude forward by a slight dimension E from the front surface of the side member 19, and the portion between the left and right bulging portions 22a is gently curved in a forward concave shape. ing. When the bulging portion 22a is bent and deformed in a plan view at the time of locking, the horizontally long support plate 22 is easily elastically deformed so that the whole of the horizontally long support plate 22 moves rearwardly. Is secured.

In this embodiment, not all of the large horizontally long support plates 22 are provided with the bulging portions 22a, but are provided in several pieces centered on the horizontally long support plates 22 located in the lumbar support portions 8b, and the bulging portions 22a. The projecting dimension E of the lumbar support portion 8b is the highest, and is set to gradually decrease as the distance from the lumbar support portion 8b increases. In other words, Horizontal support plate 22 rather have easy most deformed ones point of the lumbar support portion 8b, degree of deformation easiness with distance from the lumbar support portion 8b is low. As described above, it is possible to provide the bulging portions 22a on all the horizontally long support plates 22.

As clearly shown in FIGS. 10B to 10D, at the upper end edge of each horizontally long support plate 22, as one specific example of the deformation facilitating buffer portion, a horizontally long rib 28 protruding backward is integrally formed. ing. The horizontally long ribs 28 are formed so as to extend over the entire length of the horizontally long support plate 22 (not to mention, the horizontally long ribs 28 are divided at the slits 25 and 26). Further, the horizontal ribs 28 are set such that the height is low at the base portion of the horizontal support plate 22 and the height is gradually increased toward the inside. Since the horizontally long ribs 28 are lowered at the left and right ends in this way, the horizontally long support plate 22 is easily bent and deformed within a certain range near the left and right ends.

More specifically, the body pressure of the seated person acts as a moment on the horizontally long support plate 22, and the moment increases as it goes to the left and right ends of the horizontally long support plate 22. the base of the strength of the plate 22 is secured, the Horizontal ribs 28 is lower toward the ends, synergistic with this that Habasema portion 27 is formed on the left and right end portion close of the oblong support plate 22 as an effect, Horizontal support plate 22 portion is bent and deformed largely around the contact approximately Habasema section 27 by the load of the seated person, thereby, it can be ensured and high cushioning and fit. The narrow portion 27 can be realized by forming a horizontally long slit.

  As can be understood from the above description, the horizontal support plate 22 is deformed intensively in a certain range near the left and right ends. For this reason, when locking, the horizontal support plate 22 It will be deformed such that it will move backward while supporting the back from a large area. As a result, it is possible to ensure a high cushioning property while balancing the body support stability and the fit. Further, since there is no stress concentration, durability is high.

  Needless to say, the rigidity and ease of deformation can be adjusted by changing the height and thickness of the horizontally long ribs 28 in each horizontally long support plate 22. The horizontally long ribs 28 may be formed at both upper and lower edges of the horizontally long support plate 22, or may be formed at a portion between the upper edge and the lower edge of the horizontally long support plate 22.

(4). Connection structure of back plate and back frame As shown in FIGS. 11 to 13, a portion of the side frame 12 in the back frame 7 where the back plate 8 overlaps (rearly inclined portion) has a groove shape opened forward. It has become. Further, a portion of the upper frame 13 in the back frame 7 that overlaps the upper member 20 of the back plate 8 is also formed in a groove shape with a forward opening. On the other hand, each member 19, 20, 21 of the back plate 8 has a groove shape opened rearward, and the side member 19 of the back plate 8 and the back frame 7 are overlapped as shown in FIG. Are overlapping each other.

In this case, a step portion 30 that meshes with each other is formed on the overlapping surface of the side member 19 of the back plate 8 and the side frame 12 of the back frame 7, thereby achieving positioning and prevention of lateral displacement. More specifically, when locking, the side member 19 of the back plate 8 receives an external force that moves to the left and right inside. Therefore, the step portion 30 is formed outwardly in the left and right direction as described in the side frame 12 of the back frame 7. This prevents the side member 19 of the back plate 8 from shifting to the left and right inside during locking. The skin material 10 is sandwiched between the back plate 8 and the back frame 7.

As shown in FIG. 11 to 13, in the grooves of the side members 19 in the back plate 8, the plate-like male shape regulating member 31 in the vertical longitudinal are three spaced apart vertically. On the other hand, the side frame 12 of the back frame 7, the regulating member 31 fits female regulating member 32 of the back plate 8 are 3 pairing. By fitting these regulating bodies 31 and 32 together, the back plate 8 is held so as not to be laterally displaced with respect to the back frame 7.

Further, in the groove of the side member 19 in the back plate 8 , two first hooks 33 are formed so as to be separated from each other in the vertical direction when viewed from the side. Are formed with two upward hook-shaped second engaging claws 34 that mesh with the engaging claws 33. More intermesh physician these engagement claws 33 and 34, the back plate 8 is immovably held positive with respect to the back frame 7.

Further, as shown in FIGS. 11 and 13, the third engagement claws 35 having a hook shape facing downward in a side view are formed at the left and right ends of the upper member 20 in the back plate 8, while the upper member 20 in the back frame 7. The inner piece 36 is formed with an engagement hole 37 into which the third engagement claw 35 is fitted.

  As shown in FIG. 13, bag-shaped nut holding portions 39 that are opened inward (laterally) are formed on both sides of the upper member 20 in the back frame 7 where the upper member 20 acts. A nut is fitted in the nut holding portion 39 so as not to rotate, and a screw (not shown) is screwed into the nut from behind the back frame 7. A headrest (not shown) is fixed with screws.

It protrudes from the hole 40 of the forward opening opened in the nut holding part 39. On the other hand, on the left and right inner side of the third engaging claws 35 of the upper member 20 of the back plate 8, on the stopper 41 for holding the back plate 8 upwardly immovable by hitting from below is formed in the screw.

  The upper stopper 41 has a lower horizontal wall and an upper horizontal wall extending in opposite directions to each other and a vertical wall connecting the upper and lower walls. When the upper stopper 41 is fitted into a space in the back frame 17, the back plate 8 is moved up and down. While maintaining a state where there is no backlash to the left and right, the third engagement claw 35 is prevented from being deformed during locking or the like, thereby preventing its separation.

For example, as shown in FIG. 10B, the side member 19 of the back plate 8 and the side frame 12 of the back frame 7 are provided with a plurality of auxiliary stoppers 42 for regulating the front-rear position at appropriate intervals. ing. Further, as shown in the lower part of FIG. 12, the top plate 17 of the side frame 12 in the back frame 7 and the side member 19 of the back plate 8 corresponding thereto support the back plate 8 so as not to move forward. A pair of hook-shaped lower engaging claws 38a, 38b is formed.

The back plate 8 is attached by the following procedure. That is, first, the back plate 8 is moved from top to bottom to engage the lower engagement claws 38a and 38b, and then the back plate 8 is lifted slightly to make the first engagement claw 33 and the second engagement claw 34 And finally, the third engagement claw 35 is fitted into the engagement hole 37. As a result, the back plate 8 is held so that it cannot be displaced vertically and horizontally and back and forth with respect to the back frame 7.

A reinforcing plate (not shown) is fixed to a portion of the skin material 10 sandwiched between the back plate 8 and the back frame 17, and the reinforcing plate is fitted on the engaging claws 33 and 34.

(5) Locking mechanism Next, the locking mechanism will be briefly described with reference to FIG. The seat 4 has a structure in which a cushion material is stretched on the upper surface of an inner shell (not shown) made of synthetic resin, and the inner shell is attached to an intermediate member 43 made of resin so that the front and rear positions can be adjusted.

The intermediate member 43 is connected to the base 3 via a front link 44 and a rear link 45. The front link 44 is the shape of a block-shaped appearance, the bottom is fitted from above to the first axis 46 of the right and left longitudinal attached to the front of the base 3, the shaft portion 47 formed thereon, A front bearing 48 formed on the intermediate member 43 is fitted.

  The rear link 45 is made of a metal plate and has a U-shaped downward opening having left and right side plates when viewed from the front. The left and right ends of the rear link 45 have forward bearings 45a extending from the side plates. The rear link 45 is connected to the base 3 so as to be rotatable by a horizontally elongated second shaft 49. The rear link 45 has the same function as the bell crank. The third shaft 50 is inserted into the front end (tip) of the bearing portion 45 a in the rear link 45, and the rear bearing portion 51 of the intermediate member 43 is fitted to the third shaft 50.

  A bearing hole (not shown) is formed at the front end of the side arm 15 in the back frame 7 so as to be fitted to the second shaft 49 from the rear, and the side arm 15 is fitted to the second shaft 49 in the state where the side arm 15 is fitted. A front member 16 formed integrally with the rear link 15 is fixed to the rear link 45 with screws. Therefore, the back frame 7 rotates integrally with the rear link 45. A left and right support shaft 52 is fitted to the rear end portion and the lower end portion of the rear link 45, and the side arm 15 of the back frame 7 is supported by the support shaft 52.

A locking unit 53 fixed to the lower surface of the rear link 45 is disposed at the rear portion of the base 3. The locking unit 53 comes into contact with an elastic body (for example, rubber), and the back frame 7 tilts backward against the elasticity of the elastic body. An operation unit 54 is fixed to the lower link 45, and the lever 55 provided on the operation unit 54 is rotated to adjust the strength of the locking and to switch between locking and locking.

  The front link 44 is tilted forward with respect to the vertical posture so that the top is forward when viewed from the side, and the third shaft 50 is positioned in front of the second shaft 49. Accordingly, the front link 44 and the rear link 45 constitute a link mechanism similar to a parallel link mechanism, and the load of the seated person acts so that both the links 44 and 45 are in a forward inclined posture. When the seated person leans on the backrest 5, a large moment is applied to the backrest 5, so that both links 44 and 45 are rotated. Then, the seat 4 is lifted and moved backward. Therefore, the seated person's load (part of the body weight) acts to return the backrest 5. In other words, a part of the weight of the seated person performs the same function as the elastic body.

  A part of the weight of the seated person acts to return the backrest 5 when rocking, but since the force is proportional to the weight of the seated person, the resistance during rocking is balanced in response to the weight of the seated person. doing. For this reason, the same rocking hardness can be provided regardless of the difference in weight (or difference in physique).

  That is, for example, in a chair in which only a coil spring is used as a rocking resistance, the spring feels soft when the weight of the seated person is heavy, and the spring feels hard when the weight of the seated person is light. Therefore, the initial elastic force of the spring is adjusted by rotating a knob or the like. However, in this embodiment, the weight of the person acts as a resistance to rocking, so that Can provide the same rocking feeling. Furthermore, the backward tilting moment of the backrest 5 when rocking increases in proportion to the weight, but the resistance caused by the seat 4 going down is also proportional to the weight. Such a rocking feeling can be provided.

(6). Other Embodiments / Reference Examples FIG. 15 shows another embodiment. Among these, in the second embodiment shown in (A), the horizontally long support plates 22 adjacent to each other in the vertical direction are connected to each other at the left and right side portions by an oval shape portion 57. In this case, a bulging portion (not shown) is formed near the base portion of the horizontally long support plate 22 as the deformation facilitating buffer portion, but other configurations such as a narrow portion may be added.

(B) shows a reference example. In this reference example, an upper and lower slit 58 is formed as a deformation facilitating buffer portion of the horizontally long support plate 22, and the horizontally long support plate 22 is allowed to extend and deform in the longitudinal direction. doing. The third embodiment shown in (C) is another example of the narrow portion 27 . In the fourth embodiment shown in (D), the entire horizontally long support plate 22 is formed as a bulging portion that projects by a dimension E in front of the side member 19.

(7). Others The present invention can be embodied in various ways other than the above embodiments. For example, a structure in which a back plate and a back frame are integrated can be used, or a structure without an upper member and a lower member can be used. Moreover, the application object of the present invention is not limited to the rotary chair, but can be applied to a fixed chair of a pipe chair that is frequently used for conferences.

  The present invention is useful when applied to a chair. Therefore, it can be used industrially.

3 Base 4 Seat 5 Backrest 7 Back Frame 8 Back Plate 9 Cushioning Body 12 Back Frame Side Frame 13 Back Frame Upper Frame 15 Back Frame Side Arm 17 Back Frame Vertex 19 Back Plate Side Member 20 Back Plate Upper Member 22 Back support plate of back plate 22a Swelling portion as deformable buffer portion 24 Joint 25, 26 Slit 27 Narrow portion as an example of deformable buffer portion 28 Rib

Claims (5)

A support body that receives the body pressure of the seated person, and the support body is disposed between left and right side members that extend in the vertical direction so as to form left and right side portions of the support body, and the left and right side members. It is provided with a plurality of horizontally long support plates arranged in multiple stages, and the support body is a synthetic resin integral molded product, and the left and right side members and the horizontally long support plate group are connected in series with a backrest or a seat. There,
A deformation facilitating buffer unit that makes it easy for the horizontal support plate to bend and deform so that the horizontal support plate moves backward by the body pressure of the seated person at least at a part of the lateral base of the group of the horizontally long support plates. In order to bend and deform into a curved state in plan view due to the body pressure of the person, it is formed in a state with a lateral extension so as to extend inward from the base part of the horizontally long support plate,
Chair back or seat. A narrow portion in which the vertical width dimension of the horizontal support plate is substantially narrower than other portions is formed near the left and right roots of the horizontal support plate, and the narrow portion is formed into the deformation facilitating buffer portion. And
Serial mounting the backrest of the chair to claim 1. The root vicinity of the horizontal support plate forms a lower slit open upward in the slit and landscape L-shaped top which open upward in landscape L-shaped, forming a width narrower portion by the vertical slit And the portion surrounded by the slit is a horizontally long lip, and the horizontally long lips of the horizontally long support plates adjacent to each other are connected by a joint,
The chair back according to claim 2. At the upper end edge or lower end edge or upper and lower end edges of the horizontally long support plate, a horizontally long rib that protrudes backward and extends in the left and right direction is formed. It is formed with the deformation facilitating buffer unit by lowering,
The backrest of the chair described in any one of Claims 1-3. The base portion of the horizontally long support plate is a bulging portion that protrudes in front of the side member in a state of being convexly convex in plan view, and this bulging portion forms the deformation facilitating buffer portion.
The backrest of the chair as described in any one of Claims 1-4.

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