JP2010099103A - Rocking chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve improvement of the beauty and strength of a rocking chair whose backrest includes a back frame covered with a support sheet. <P>SOLUTION: The backrest 5 includes a back frame 13 and a support sheet 14. The back frame 13 includes right and left side members 16, an upper member 17 and a lower member 18. The side members 16 of the back frame 13 are fastened to a rocking frame 8. The side members 16 are put on the rocking frame 8 from the outside right and left. The lower member 18 is put on a joint frame 12 from the front side. The outer surfaces of a back strut 10 and the side members 16 are smoothly continued. The oneness of the back strut 10 and the back frame 13 is created while appealing the presence of the back strut 10. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rocking chair whose backrest tilts backward against elastic means (spring means), and in particular, a rocking chair of a type in which a mesh-like support sheet is stretched on a back frame. ing.

  Many mechanisms for tilting the backrest of a rocking chair have been proposed or implemented, but in general, a swing frame (back frame) is connected to the base so as to be tilted backward, and the swing frame is attached to the swing frame. Often a backrest is attached. There are many configurations for attaching the backrest to the swing frame. In general, however, the backrest is often attached to the swing strut integrally or separately with the backrest facing upward. As an example, in Patent Documents 1 and 2, the back column is extended to the upper end portion of the backrest, and there is a gap between the backrest and the back column.

  On the other hand, there is a chair that receives the body pressure of a seated person with a support sheet as a configuration in which a mesh (or net-like) support sheet is stretched on a back frame with the backrest opened forward and backward, and this is an example Is disclosed in Patent Document 3. In Patent Document 3, the back frame has a shape that opens back and forth, and a swing frame that is coupled to the base is integrally formed. In other words, the back frame is formed integrally with the swing frame.

In addition, the construction of the backrest with a support seat is also applied to a non-rocking chair. As an example, Patent Document 4 discloses a rectangular back frame with a support seat stretched on the left and right sides of the back column. In addition, Patent Document 5 discloses that a cylindrical support member is fitted and attached to the left and right back struts from above, and a support sheet is attached to the left and right support members.
JP 2007-319288 A JP 2000-079034 A Japanese National Patent Publication No. 8-507935 JP 2001-224461 A JP 2001-008785 A

  In a chair with a support frame stretched on the back frame, the swing frame is preferably made of a metal material such as aluminum in order to ensure strength. The back frame is easy to process, lightweight, etc. Therefore, it can be said that the resin product is suitable. Therefore, in general, it can be said that it is practical to configure the swing frame and the back frame as separate members. Although the back frame can be made of metal, in this case as well, it is preferable to configure the swing frame and the back frame as separate members from the viewpoint of ease of processing.

  Examples of means for fixing the back frame to the swing frame include Patent Documents 1, 2, 4, and 5. In Patent Documents 1 and 2, since the back column extends to the upper end of the backrest, It is too conspicuous, and there is a possibility of lack of simplicity because the space between the back strut and the backrest is vacant.

  On the other hand, in the structure of patent document 4, since the back support | pillar is exposed to the right-and-left outer side of a back frame, when it applies to a rocking chair, there exists a possibility that an appearance may worsen. Moreover, forming the side member of the back frame in a cylindrical shape as in Patent Document 5 has a problem that the processing is troublesome and the design is restricted.

  The present invention has been made in view of such a situation, and an object of the present invention is to improve problems such as appearance and strength in a chair in which a back frame is fixed to a back column.

  The chair according to the present invention includes a seat, a backrest, and a base disposed below the seat, and a pair of left and right swing frames that are tilted rearward against spring means are connected to the base. The rear end of the left and right swing frame is a back column that rises substantially upward, while the backrest has upper and lower left and right side members, an upper member connected to the upper end, and a lower member connected to the lower end. And the back frame is fixed to the back column of the swing frame ”.

  According to the first aspect of the present invention, in the basic configuration described above, the back frame side member and the left and right back struts of the swing frame are exposed. It is fixed in a state where it is exposed to the side.

  According to a second aspect of the present invention, there is provided a mesh-like support sheet according to the first aspect, wherein the back surface of the back column and the back surface of the side member in the back frame are smoothly continuous, and the backrest is stretched on the back frame. A groove for attaching a support sheet is formed on the outer periphery of each member in the back frame, and the support sheet is stretched so as to cover the front surface of the back frame.

  According to a third aspect of the present invention, in the first or second aspect, the side member is bent in a forward convex shape in a side view so that a portion located on the waist of the seated person is a vertex portion located at the most front end. The back strut extends to the vicinity of the apex of the side member. Furthermore, the invention of claim 4 is the invention according to any one of claims 1 to 3, wherein the lower ends of the left and right back struts are connected by a horizontally long joint frame, and the lower member of the back frame is in front of the joint frame. It overlaps from the side.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the left and right width dimensions of the back frame are set to be approximately the same as the left and right width dimensions of the seat, while the left and right back struts have The frame is arranged to be shifted inward from the left and right outer surfaces of the frame, and the outer surface of the lower end portion of the side member in the back frame is an inclined surface inclined toward the base portion of the back column.

  In the invention of claim 1, since the back column and the side member of the back frame are fixed in a state where they are overlapped on the left and right, the outer surfaces of both can be aligned as in the case of claim 2, so that It can be made into a good looking chair with a sense of unity between the back strut and the side members. In particular, when the swing frame (back strut) is made of aluminum and the back frame is made of resin as in the embodiment, the texture of the aluminum appears in the appearance of the chair, so that particularly excellent aesthetics can be realized.

  Further, since the side members of the back frame are located on the left and right outer sides of the back column, when the support sheet is stretched on the back frame as in claim 2, the support sheet can be easily attached to the outer periphery of the side member. Furthermore, since the back column is disposed inside the side member in the back frame, it is possible to prevent the swing frame from being excessively exposed to the left and right sides and being in the way.

  In claim 1, various methods can be adopted as the side member attachment mode. However, when the support sheet is attached using the groove formed on the outer periphery of the back frame as in claim 2, the back frame of the chair is viewed from the front of the chair. Since the whole is covered with a support seat, it is possible to use almost the entire area of the backrest viewed from the front of the chair as the body pressure surface of the seated person, improving the body pressure support function and soft impression to the person Can improve the product value of the chair.

  In recent years, with regard to chairs, a lumbar support function for supporting the seated person's lumbar part (particularly the part centered on the third lumbar vertebra) from the back has been regarded as important in order to hold the seated person in the correct posture. In this case, in order to exert the lumbar support function, the backrest needs to be bent in a forward convex shape in the side view so that the portion corresponding to the lumbar part of the seated person is located in the foremost side view.

  Then, when the back frame is formed in a forward convex shape in a side view so that the backrest exhibits the lumbar support function, the height of the back column is extended to the vicinity of the apex of the back frame as in claim 3. If you set the back, the back strut is moderately high, so it will support the moment applied to the backrest when locking properly, while preventing the back strut from being exposed excessively and making it a good looking chair it can.

  The back frame also functions as a reinforcing member that connects the left and right back struts. However, when the left and right swing frames (back struts) are connected by a joint frame as in claim 4, the swing frames (back struts) The connection strength can be further improved. Also, when assembling the chair, the left and right swing frames are joined together by the joint frame and attached to the base in a predetermined posture, so that the work of fixing the back frame can be performed easily. .

  In a rocking chair that has left and right swing frames attached to the base, it is preferable to move the left and right swing frames to the inside as much as possible so that they do not protrude from the left and right sides of the seat. In general, since the dimensions are set to the same level, if no measures are taken, there is a concern that a step is generated between the left and right outer surfaces of the back column and the left and right outer surfaces of the side members in the back frame, and the appearance is deteriorated. On the other hand, when the structure of claim 5 is adopted, the outer surface of the side member in the back frame and the outer surface of the back column are smoothly continuous by forming the inclined surface on the side member of the back frame, so that the aesthetics are excellent. Can be made with a chair.

  Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to a swivel chair frequently used for office work. In the following description, the left and right words for specifying the direction are used, but the left and right directions are based on the direction in which the seated person faces.

(1). Outline First, an outline of a chair will be described with reference to FIGS. 1A is a perspective view of a chair, FIG. 2B is a partially cutaway front view of a backrest, FIG. 2 is a side view, FIG. 3A is a rear view of the chair, and FIG. Is a perspective view from the rear with a part of the backrest omitted, FIG. 4 is a separated perspective view seen from the front, FIG. 5 is a separated perspective view seen from the rear, and FIGS. 6A and 6B are mainly shown in FIGS. It is a separation perspective view showing a locking mechanism.

  For example, as shown in FIGS. 1 to 3, the chair is disposed above the base 3 as a main element, a leg device 1 having a leg column 2 (gas cylinder), a base 3 fixed to the upper end of the leg column 2, and the base 3. A seat 4, a backrest 5, and a headrest device 6 attached to the backrest 5 as an optional item are provided. The leg 1 includes a plurality of branch legs 7 extending radially, and a caster is provided at the tip of each branch leg 7.

  A pair of left and right swing frames 8 are arranged on the left and right sides of the base 3. The swing frame 8 is composed of a base 9 that is tilted rearward in a posture close to horizontal when not rocked, and a back column 10 that rises from the rear end. The front end portion of the base portion 9 is connected to the base 3 by left and right longitudinal support shaft portions 11 so as to tilt backward (rotate) around the front end portion of the swing frame 8. The swing frame 8 employs a metal molded product such as aluminum die cast, but may be a resin molded product or a sheet metal product. The left and right swing frames 8 are connected by a joint frame 11 at a corner where the base 9 and the back column 10 are connected.

  The backrest 5 has a configuration in which a support sheet 14 is stretched on a back frame 13 having a substantially square shape when viewed from the front, and the back frame 13 is fixed to a column 10 of the swing frame 10 with screws (details will be described later). The back frame 13 is gently curved in side view so that the portion corresponding to the waist of the seated person is the front end in side view, and therefore the support seat 14 (or backrest 5) has a lumbar support portion 14a. . The lumbar pad 14 is in contact with the left and right sides of the lumbar support portion 14a of the support sheet 14 from the back side. The support sheet 14 is recessed in a forward concave shape in plan view. Further, the support sheet 14 of the present embodiment has an appearance of a vertically striped pattern in which vertically long sparse parts and dense parts are alternately arranged in the left-right direction, and the sparse part can be seen through back and forth.

  For example, as shown in FIG. 4, the back frame 13 is a resin molded product. The left and right side members 16 extend long in the vertical direction, the upper member 17 is connected to the upper ends of the left and right side members 16, and the lower ends of the left and right side members 16. It consists of the lower member 18 connected to. Therefore, the back frame 13 has a substantially rectangular shape when viewed from the front. The upper member 17 and the lower member 18 are gently curved in a forward concave shape in plan view.

  As described above, the swing frame 10 is connected to the base 3 by the support shaft portion 9 so as to tilt backward with the front end portion as the center. In this embodiment, the support shaft portion is used as the locking spring means. The torsion bar built in 9 is adopted. The left and right intermediate portions of the torsion bar are non-rotatably held by the base 3, and both left and right end portions are fixed to the front end portion of the swing frame 8. For this reason, the swing frame 8 tilts backward while torsionally deforming the torsion bar.

  The support shaft portion 11 protrudes greatly on the left and right outer sides of the base 3, and for this reason, the swing frame 8 is also arranged considerably outside the base 3. However, as can be understood from FIG. 3B, for example, the swing frame 8 is positioned on the inner side of the left and right outer surfaces of the seat 4. Therefore, the swing frame 8 does not interfere with human walking.

  The seat 4 has a resin inner shell (not shown), a cushion stretched on the upper surface thereof, and an outer shell 19 that supports the inner shell. Since the relationship with the present invention is thin, the details are omitted, but the outer shell 19 of the seat 4 is attached to the intermediate member so that it can be moved back and forth, and the front portion of the intermediate member is connected to the base 3 by the front link 20. . The upper end of the front link 20 is connected to a longitudinal auxiliary frame member 21. The auxiliary frame member 21 can slide back and forth with respect to the intermediate member, and moves integrally with the seat 4 (outer shell 19).

  As shown in FIGS. 4 to 6, a rear link 22 is disposed on the inner side surface of the swing frame 10. The rear link 22 has a substantially L shape in a side view similar to the swing frame 8, a standing portion 22 a extends along the inner surface of the back column 10 in the swing frame 8, and the rear link 22 is a standing portion. It is connected to the oscillating frame 8 by a pivot pin (screw: not shown) at a position slightly in front of the base of 22a. The front end of the rear link 21 protrudes upward, and this is connected to the rear end portion of the auxiliary frame member 21 by a rear pin 24.

  Therefore, when the backrest 5 (and the swing frame 8) tilts backward, the seat 4 tilts backward while moving backward. As shown in FIG. 6, an intermediate member to which a seat 4 is attached while a guide slot 25 having a posture slightly tilted rearward with respect to the horizontal is formed on the inner surface of the front and rear intermediate portion of the swing frame 8. Is provided with a guide pin 24 ′ (see FIG. 4) that is slidably fitted into the guide slot 25. Since the guide pin 24 ′ is guided by the guide elongated hole 25, the seat 4 is not independently retracted and tilted backward, and the interlocking relationship with the swing frame 8 is forced. In FIG. 6, reference numeral 26 denotes a resin cap that is mounted in the guide long hole 25, and reference numeral 27 denotes a protective bush into which the guide pin 24 ′ is fitted.

  When the seated person leans against the backrest 5, the standing portion 22 a of the rear link 22 also tilts backward, but also tilts relatively backward with respect to the back column 10. That is, the rate at which the upright portion 22a of the rear link 22 tilts backward is greater than the rate at which the back column 10 tilts backward. And the lumbar pad 15 mentioned above is attached to the upper end part of the standing part 22a in the rear link 22 so that height adjustment is possible. Accordingly, the lumbar pad 15 is retracted relative to the back column 10 at the time of locking, and for this reason, when the support sheet 14 is locked, the tension is loosened.

  Now, when a person performs work / work such as personal computer operation in a non-locking state, it is preferable that the upper body supports the lumbar part from behind by the lumbar support part 14a of the support sheet 14. Therefore, in a non-locking state, it is preferable that the lumbar support portion 14a protrudes considerably forwardly convex in a side sectional view. On the other hand, if the lumbar support part 14a is in a state of being largely protruded and is shifted to the locking state, the waist part may be excessively pushed up. Therefore, in the present embodiment, the lumbar pad 15 is moved backward relative to the back column 10 during locking to loosen the tension of the support sheet 14.

  The headrest device 6 has left and right head columns 27 rising from the left and right inner surfaces of the side member 16 in the back frame 13 (only one head column 17 is shown in FIGS. 1A and 4). The headrest 28 is attached to the head column 27 so that the height can be adjusted.

  The head column 27 is connected to the side member 16 by a pin (or a bin) so as to rotate back and forth around a portion near the lower end of the head column 27, and the lower end of the head column 27 is connected to the rotation absorbing device 29. It is connected to the upright part 22a of the rear link 22 via. At the time of locking, the head column 27 rotates so that the upper part thereof moves forward. Accordingly, the seated person has an advantage that the display of the personal computer can be easily viewed without raising his / her head while being in a locked state, and there is no need to lift the book when reading. Further, the rotation absorbing device 29 has a built-in spring, and the head column 27 can be tilted backward against the spring.

(2). Swing Frame and Joint Frame Next, the relationship between the swing frame 8 and the back frame 13 will be described in detail with reference to FIG. 7 is a perspective view of the back column 13 attached to the back column 10. FIG. 8 is a perspective view of the swing frame 8 and the joint frame 12. FIG. 9 is a perspective view of the swing frame 8 and the joint frame 12. 10 is a perspective view showing the relationship between the back frame 13, the swing frame 8, and the joint frame 12. FIG. 11A is a perspective view of the upper portion of the back column 10, and FIG. 10B is a side view of the back frame 13. FIG. 3 is a cutaway perspective view of a member 16. 12A is a partial side view in the non-locking state, FIG. 12B is a partial side view in the locking state, and FIG. 13 is XIII-XIII with the lumbar pad 15 slightly shifted downward in FIG. FIG. First, the swing frame 8 and the joint frame 12 will be described.

  As described above, the swing frame 8 is an aluminum molded product. For example, as shown in FIG. 9 (A), the base 9 of the swing frame 8 is formed in a generally bowl-like shape that is open to the inside, and is formed in the inside. Reinforcing ribs are provided. In addition, a rectangular hole 31 (see FIG. 6A) that opens outwardly and protrudes slightly outward is formed in a substantially middle portion of the base 9 of the swing frame 8. The square hole 31 is for attaching an armrest device, and is closed with a cover 32 (see, for example, FIG. 5) when the armrest device is not attached.

  For example, as shown in FIG. 8A, the base 9 of the swing frame 8 is provided with a boss portion 33 into which the rear link 22 is fitted. Therefore, the above-described pivot pin (screw) accurately functions to prevent the rear link 22 from coming off. For example, as shown in FIG. 7B, the base 9 of the swing frame 8 is provided with a lower inside cover 34 for covering the rear link 22.

  For example, as shown in FIGS. 8 and 13, the back column 10 has a side plate 35 and a back plate 36. The side plate 35 extends in the front-rear direction in a plan view, but the back plate 36 is inclined so as to shift backward as it goes to the center of the backrest 5 in a plan view. Therefore, the back column 10 is deformed in a plan view. It is L-shaped. A low inward front rib 37 is formed at the front end of the side plate 35 in the back column 10. Therefore, the inside of the side plate 35 has a shallow groove shape. A group of reinforcing ribs 38 having the same height as the front ribs 37 is formed inside the side plate 35.

  The reason why the back column 10 is formed in a modified L shape is that the upright portion 22a of the rear link 22 is arranged in a space surrounded by the side plate 35 and the back plate 36. The standing portion 22 a of the rear link 22 is covered with an upper inside cover 38. As shown in each drawing such as FIG. 8A and FIG. 11A, a bracket portion 40 for attaching the upper inside cover 39 is provided on the upper portion of the back plate 36 in the back column 10. An inward rear rib 41 extending vertically is formed on the back plate 36 of the back column 10.

  As described above, the head column 27 tilts forward in conjunction with the rear tilt of the rear link 22, and the rotation absorbing device 29 is connected to the upper end of the standing portion 22 a in the rear link 22. In some cases, the headrest device 6 is not attached. In this case, for example, as shown in FIG. 11A, a top cap 42 is attached to the upper end of the back column 10. An engaging portion 43 for attaching the top cap 42 is provided on the inner surface of the upper end portion of the back plate 36 in the back column 10.

  For example, as shown in FIGS. 8 to 10, the joint frame 12 is gently curved in a forward concave shape in a plan view and is formed in a groove shape with a forward opening, and a plurality of reinforcing ribs are provided therein. . A fitting portion 44 that protrudes slightly downward and extends toward the front side is integrally provided at both left and right end portions, and the fitting portion 44 is fitted into the corner portion of the swing frame 8 from the inside. Two screws 45 inserted from below into the swing frame 8 are screwed into the fitting portion 44, and the joint frame 12 is fastened to the swing frame 8 with screws 45.

  For example, as shown in FIG. 9, three protrusions 46 and 47 for positioning are formed on the inner surface of the corner portion of the swing frame 8, while the protrusions are formed on the fitting portion 44 of the joint frame 12. Concave portions 48 and 49 are formed to be fitted into the 46 and 47. The two seats 46 on the front side have insertion holes for screws 45. By fitting the protrusions 46 and 47 and the recesses 48 and 49 together, the joint frame 12 is firmly fastened to the swing frame 8 in a state where it cannot be displaced. On the upper surface portion of the joint frame 12, a flange portion 12a protruding forward is formed.

  The joint frame 12 uses an aluminum molded product in the same manner as the swing frame 8. Although it is not impossible to manufacture the swing frame 8 and the joint frame 12 as an integrated structure, this is not only troublesome but also troublesome to assemble the chair such as attaching a torsion bar. . On the other hand, in this embodiment, the frame body composed of the swing frame 8 and the joint frame 12 is formed as a sturdy structural product without impairing the ease of processing of the swing frame 8 and the ease of assembly of the chair. be able to. This is also one of the advantages of this embodiment.

  The back strut 10 extends to the top of the side member 16 located at the foremost side as viewed from the side (ie, around the lumbar support portion 14a). When viewed as the backrest 5, the backrest 5 extends approximately to the middle of the upper and lower portions of the backrest 5. Thus, since the back column 10 has a considerable length, the support strength of the backrest 5 is ensured, and the back column 10 does not extend to the full length of the backrest 5, so that the back column 10 is excessively exposed. And it does not give a sense of incongruity. Further, it is not an obstacle to the mounting of the headrest device 7.

(3) Back frame As shown in FIG. 11B, for example, the side member 16 of the back frame 13 overlaps the back column 10 of the swing frame 8 from the left and right outer sides. The side member 16 has a substantially trapezoidal cross-sectional shape in which the front-rear width gradually decreases toward the left and right sides, and the front member 51 and the rear member 52 both incline backward so as to shift backward as they approach the center of the backrest 5. Yes. The reason why the front surface 51 of the side member 16 is inclined backward is to allow the support sheet 14 to be deformed so as to escape backward due to body pressure, and to the position of the lumbar support portion 14a of the support sheet 14. This is based on two main reasons for securing the installation space.

  The reason why the back surface 52 of the side member 16 is inclined backward is mainly for improving the aesthetics. As clearly shown in FIG. 13, the back surface 52 of the side member 16 and the back surface 52 of the back column 10 are smoothly continuous with a very loose curved surface. It has an excellent appearance with a sense of unity.

  As clearly shown in FIG. 3 (A), the left and right back struts 10 are inclined at a gentle angle so that the distance increases as they go upward, and the lower ends of the back struts 10 are somewhat larger than the left and right outer surfaces of the seat 4. Only the dimensions are inside the left and right. On the other hand, the left and right side members 16 of the back frame 13 are also inclined at a slight angle, like the back column 10. The outer surface 53 of the side member 16 in the back frame 13 is a substantially flat surface, and the lower end portion thereof is an inclined surface 53 a that is inclined inward toward the base portion 9 of the swing frame 8. Due to the presence of the inclined surface 53a, the sense of unity between the side member 16 and the swing frame 8 is further enhanced. Note that the front and rear width of the inclined surface 53a increases as it goes down.

  The outer peripheral surface of each member constituting the back frame 13 is a flat surface. As clearly shown in FIG. 13, the groove 54 is formed to extend long on the flat surface constituting the outer periphery of each member, and the edge member 55 fixed to the end edge of the support sheet 14 is formed in the groove. It is inserted in the article 54. The edge member 55 is divided for each member.

  Since the support sheet 14 is attached to the outer peripheral surface of the back frame 13, the entire area of the front surface of the backrest 5 is a seating surface, and thus a person with a large shoulder width is stably supported. Further, since the back frame 13 is hidden behind the support sheet 14 (visible through), it has an appearance as if the entire back and backrest 5 are composed of the support sheet 14, and therefore, a unique aesthetic is provided. It is evident.

  For example, as shown in FIG. 10, the back column 10 of the swing frame 8 is slightly narrower as it goes upward, and the side member 16 of the back frame 13 becomes larger in plan view as it goes down. . Therefore, the strength is ensured (the strength is necessary because a large moment is applied to the lower portion), and a smooth continuous state between the back frame 13 and the back column 10 is secured.

  For example, as shown in FIGS. 10 and 11, a portion of the side member 16 that overlaps the back column 10 has a groove shape that opens inward, and a plurality of reinforcing ribs 56 are provided inside. This is for example to equalize the wall thickness as much as possible to prevent sink marks during molding.

  As shown in FIG. 13, the back column 10 is fastened to the back column 10 with screws 57 and nuts 58. The screw 57 is inserted into the side plate 35 of the back column 10 from the inside, and the nut 58 is fitted into a nut hole 59 of a forward opening formed in the side member 16 and is held unrotatable. Since the nut hole 59 is opened to the front, the nut hole 59 is hidden by the support sheet 14 and is hardly visible, so that there is no problem in aesthetics. The side member 16 is fixed to the back column 10 at two positions on the upper and lower sides. For example, in FIG. 10, a screw insertion hole 60 of the side member 16 is clearly shown.

  For example, as shown in FIG. 4, the left and right two bracket portions 61 are formed on the upper member 17 constituting the back frame 13 in order to attach a handle or a hanger.

  In this embodiment, the relationship among the swing frame 8, the joint frame 12, and the back frame 13 is also taken into consideration. This point will be explained. The back frame 13 overlaps the back column 10 and the joint frame 12 from the front side, and the side member 16 overlaps the outer surface of the back column 10. In order to realize such an overlap without a sense of incongruity, for example, as shown in FIG. The bottom end of the side member 16 is overlapped on the outer surface of the back column 10 by the lapping.

  Further, as described above, the flange 12a is provided on the upper surface of the joint frame 12. For this reason, the lower member 18 of the back frame 13 is connected to the flange 12a of the joint frame 12, for example, as shown in FIG. It is in a state hidden under the. For this reason, the lower member 18 is not exposed when the chair is viewed from the back (back view), and the heel has an appearance as if the joint frame 12 is a part of the back frame 13. The joint frame 12 and the lower member 18 can be fastened with screws.

  Further, for example, as shown in FIG. 9 (A), a recess 62 into which the lower member 18 of the back frame 13 enters is formed at the lower end of the side plate 35 in the back column 10. The front surface of the side member 16 and the front surfaces of the left and right end portions of the lower member 18 are aligned on the same surface (alignment of both surfaces on the same surface is important for stretching the support sheet 14).

(4) Lumber pad Finally, the lumbar pad 15 will be mentioned. The lumbar pad 15 is a resin product, and as shown in FIGS. For this reason, the support sheet 14 is smoothly supported without stress concentration on a specific part. As shown in FIGS. 12 and 13, a groove-shaped receiving portion 63 that is fitted from the front to the upright portion 22 a of the rear link 22 protrudes backward from the left and right outer ends of the lumbar pad 15. A chevron-shaped stopper projection (not shown) is formed on the inner bottom surface of the receiving portion 63, while the standing portion 22 a of the rear link 22 has a plurality of recesses 64 into which the stopper projection is fitted.

  In addition, a lateral operation piece 65 that can be picked with a finger by a person is integrally formed on the back surface of the lumbar pad 15. Therefore, the user of the chair can adjust the height position of the lumbar support 14 according to his / her preference, physique and the like. A spacer 66 that stably holds the receiving portion 63 when the lumbar pad 15 is retracted is disposed on the inner surface of the upper inside cover 39.

(5). Others The present invention can be embodied in various ways other than the above embodiment. For example, the application target is not necessarily limited to a rotating chair, and can be applied to a fixed chair such as a theater chair or a bench. The backrest is preferably a support seat system, but does not exclude the system having an inner shell and a cushion. It is also possible to configure the base of the swing frame and the back column as separate members.

  It is also possible to secure the required strength by fixing the left and right swing frames to the back frame without using a joint frame. It goes without saying that various modes can be adopted as a locking mechanism for the backrest. The back frame may be configured by fastening a plurality of members without integrally forming the entire back frame. For example, the left and right side members and the upper member may be manufactured as a single body, and the lower member may be manufactured as a separate member and fixed to the lower ends of the left and right side members 16.

(A) is a perspective view of the chair which concerns on embodiment, (B) is a partially broken front view of the backrest. It is a side view of a chair. (A) is a rear view of a chair, (B) is a perspective view from the back in the state which a part of backrest was abbreviate | omitted. It is the isolation | separation perspective view seen from the front. It is the separation perspective seen from back. It is a separation perspective view mainly showing a locking mechanism. It is a perspective view of the state which attached the back frame to the back support | pillar. 3 is a perspective view of a swing frame and a joint frame 12. FIG. 3 is a perspective view of a swing frame and a joint frame 12. FIG. It is a perspective view which shows the relationship between a back frame, a rocking | fluctuation frame, and a joint frame. (A) is a perspective view of the upper part of a back support | pillar, (B) is a fractured perspective view of the side member in a back frame. It is a figure which shows the attachment state of a lumbar pad, (A) is a partial side view of the lumbar pad location in a non-locking state, (B) is a partial side view in a locking state. FIG. 13 is a sectional view taken along line XIII-XIII in a state where the lumbar pad is slightly shifted downward in FIG. 12.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leg apparatus 3 Base 4 Seat 5 Backrest 8 Swing frame 9 Base part of rocking frame 10 Back column of rocking frame 12 Joint frame 13 Back frame 14 Support sheet 15 Lumber pad 16 Back frame side member 53a Side member inclined surface

Claims (5)

The base has a seat, a backrest, and a base disposed below the seat, and a pair of left and right swing frames that are tilted rearward against spring means are connected to the base. The back end is a back strut that rises substantially upward, while the backrest includes a back frame that includes upper and lower left and right side members, an upper member connected to the upper end, and a lower member connected to the lower end. The back frame is fixed to the back column of the swing frame,
A chair called
The side members of the back frame and the left and right back struts of the swing frame are overlapped and fixed in a state where the side members of the back frame are exposed to the left and right outside of the back struts and the back struts are exposed to the back side.
Rocking chair. The back of the back strut and the back of the side member in the back frame are smoothly continuous, and the backrest has a mesh-like support sheet stretched on the back frame, and each member in the back frame A groove for attaching a support sheet is formed on the outer periphery of the support sheet, and the support sheet is stretched so as to cover the front surface of the back frame.
The rocking chair according to claim 1. The side member is bent in a forwardly convex shape in a side view so that the portion located on the waist of the seated person is the most apex located at the front end, and the back strut is in the vicinity of the apex of the side member Extending to the part,
The rocking chair according to claim 1 or 2. The lower ends of the left and right spine columns are connected by a horizontally long joint frame, and the lower member of the back frame overlaps the joint frame from the front side.
The rocking chair according to any one of claims 1 to 3. While the left and right width dimensions of the back frame are set to be approximately the same as the left and right width dimensions of the seat, the left and right back struts are arranged inwardly from the left and right outer surfaces of the seat and the back frame, The outer surface of the lower end of the side member is an inclined surface inclined toward the base of the back column,
The rocking chair according to any one of claims 1 to 4.