JP2013103068A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve compact roll-in in a chair which rolls in the front part of a seat downward and deforms it.SOLUTION: The front part of a seat inner shell 8 is a deformation allowed part having many front slits. A seat outer shell 7 is separately constituted of a fixed outer shell and a sliding outer shell 11, and the front part 8d of the seat inner shell 8 is rolled in downward interlocked with the retracting movement of the slide outer shell 11. At the front part of a cushion 9, a deformation allowed part 9b having a column of groove lines 33 is formed. Projections 34 between the groove lines 33 are mounted on the support bar part 29 of the seat inner shell 8. Thus, biting between the deformation allowed part 9b of the cushion 9 and the deformation allowed part 8a of the seat inner shell 8 does not occur, and the front part of the seat 4 can be smoothly rolled in compact.

Description

  The present invention relates to a chair capable of adjusting the longitudinal length of a seat.

  In the chair, as a technique for adjusting the front and rear length of the seat (front and rear position of the front end), as disclosed in Patent Documents 1 to 3, for example, a method of winding the front portion of the seat downward has been proposed. In these prior arts, the front part of the seat is formed as a deformation-permitting part, the front end of the deformation-permitting part is fixed to a horizontally long front bar, and the front part of the seat is rolled back and forth by moving the front bar back and forth. It is.

  Among them, in Patent Document 1, the seat has a structure in which a cushion is placed on a flexible belt, and the cushion is in a simple flat plate state. On the other hand, in Patent Document 2, the seat is provided with a sheet material that can be bent and deformed, and a plurality of longitudinal slits are arranged in parallel on the sheet material, and the deformation is facilitated by the presence of the slit group. Further, in Patent Document 3, the portion of the cushion that is engulfed and deformed is not supported in the stretched state, but is simply engulfed using the elastic deformation of the cushion.

Japanese Patent Publication No. 07-77567 Special table 2010-516433 Utility Model Registration No. 3076862

  Now, the cushion is for giving the user a high sitting comfort, and a certain thickness is required to ensure high fit and cushioning. However, in the form in which the cushion is simply wrapped as in each patent document, the curvature radius of the winding has to be increased as the thickness of the cushion increases, and then the thickness of the front part of the seat increases and the appearance is increased. There is a problem that it may become worse and a large force is required for the entrainment operation.

  The present invention has been made in view of such a situation, and prevents the front portion of the seat from becoming excessively thick while ensuring a necessary thickness for the cushion. This is also to secure the support function of the thigh.

  According to the present invention, as described in claim 1, the seat has a structure in which a cushion is disposed on the upper surface of the seat inner shell, and the front portion is directed downward at the front portion of the cushion and the seat inner shell. In the configuration in which the front and rear lengths of the seat are shortened by winding the seat inner shell and the front part of the cushion downward, the deformation allowance part of the cushion is It is configured by forming a plurality of laterally elongated horizontal grooves that are opened downward, and the portion between the adjacent grooves is a laterally elongated ridge. The deformation | transformation permission part which has a row | line is mounted on the deformation | transformation permission part of the said seat inner shell from the top.

  The present invention and the structure of claim 2 are also included. The present invention is characterized in that, in claim 1, the deformation-allowing portion at the front portion of the seat inner shell is formed by forming a plurality of laterally elongated slits so as to be arranged in the front-rear direction. The intermediate portion is a horizontally long support bar portion on which the protrusion of the cushion is placed.

  Further, the present invention includes the structure of claim 3. According to a second aspect of the present invention, in the second aspect, the ridges and grooves and the support bar portion are in a non-parallel posture in a plan view. In any one of the above, the seat inner shell is supported by a seat outer shell, and the seat outer shell includes a slide seat outer shell that supports a deformation allowing portion of the seat inner shell, and the slide seat outer shell moves back and forth. It is separated into a fixed seat outer shell that is freely mounted.

  In this invention, since a cushion is wound downward by making it deform | transform so that a groove may be closed, it can be wound compactly. In this case, since the deformation allowable portion of the cushion is placed on the seat inner shell from above, the seat inner shell and the cushion are not engaged with each other, and the wrapping operation (operation for reducing the seat depth) can be performed reliably and smoothly. .

  Further, for example, in Patent Document 1, the front part of the cushion must be drawn to the lower side of the front bar with the front bar as a fulcrum, which complicates the structure. However, in the present invention, the seat inner shell is also together with the cushion. Since it is involved, the seat inner shell and the cushion are involved only by pulling the front end of the seat inner shell backward, so that the structure can be simplified.

  The means for providing the deformation allowing portion at the front portion of the seat inner shell can adopt various structures, and if a structure having a horizontally long slit as in claim 2 is adopted, it can be accurately wound with a simple structure. And since the support bar part located between the adjacent slits is mounted on the protrusion of the cushion, the entrainment of the cushion is not hindered. In this case, if the ridge and the support bar portion are set non-parallel as in claim 3, for example, even if the ridge and the support bar portion slightly deviate back and forth due to the body pressure of the seated person, the groove is supported by the groove The body can be supported in a stable state without being depressed, and the ease of entrapping the seat can be ensured.

  If the structure of Claim 4 is employ | adopted, since the front part which winds and deform | transforms among seat inner shells is supported by the slide type seat outer shell, there exists an advantage which can support the seated person's thigh accurately.

It is an external view of the chair which concerns on embodiment, (A) is a front view, (B) is a side view. It is a perspective view of a base and a back frame. It is a separation perspective view of the peripheral part of a base. It is a separation perspective view of a seat and a seat outer shell. It is a separation perspective view of a seat. (A) is the bottom view of the front part of a seat inner shell, (B) is the perspective view which looked at the front part of the seat inner shell from the top. It is the side view which cut | disconnected the seat at the site | part which shifted | deviated slightly from the center to the right and left. It is principal part sectional drawing in the state wound up. (A) is a separated perspective view of the seat outer shell and the depth adjusting lever device (the slide type outer shell 11 is shown upside down), and (B) is a partially enlarged perspective view of the fixed outer shell 10. It is a separation perspective view of a seat inner shell and a seat outer shell. It is a separation perspective view of a seat inner shell and a slide type seat outer shell. (A) is a perspective view in a state where the fixed seat outer shell is turned over, (B) is a perspective view of an intermediate fitting, and (C) and (D) are partial enlarged views of (A).

  Next, an embodiment of the present invention will be described with reference to the drawings. In the following description, the words “front and rear” and “left and right” are used to specify the direction, but the words on the front and rear and right and left are based on the person who is seated. The front view direction is the direction facing the seated person, and therefore the left and right in the front view are opposite to the left and right viewed from the seated person.

(1). Outline of chair First, an outline of the chair will be described mainly with reference to FIGS. This embodiment is applied to a swivel chair frequently used for office work or the like. The chair includes a leg device 2 having a leg column 1 and a cutter, a base 3 fixed to the upper end of the leg column 1, and a base 3. It has a seat 4 arranged above and a backrest 5 on which a seated person can rest. The base 3 is formed in a box shape opened upward.

  For example, as shown in FIG. 3, an intermediate metal fitting 6 made of a metal plate is arranged on the base 3, and a resin seat outer shell (seat receiving member) 7 shown in FIG. It has been. The seat outer shell 7 can be connected to the base 2 without using the intermediate metal fitting 6.

  As shown in FIG. 4, the seat 4 has a resin seat inner shell (seat plate) 8 and a seat cushion material 9 disposed on the upper surface thereof. The seat cushion material 9 is a skin material such as a cloth. (Not shown) covered from above. The seat outer shell 7 is composed of two members, a fixed outer shell 10 fixed to the intermediate metal fitting 5 and a sliding outer shell 11 protruding in front thereof. The sliding outer shell 11 is connected to the fixed outer shell 10. It is attached to move back and forth.

  A portion closer to the front side of the seat inner shell 8 is a deformation allowing portion 8 c that easily bends and deforms downward in a side view, and the front end of the seat inner shell 8 is connected to the front end portion of the slide type outer shell 11. . For this reason, when the sliding outer shell 11 is slid back and forth, the front portion 8d of the seat inner shell 8 extends forward or is wound downward. Thereby, the front-rear length of the seat 4 (that is, the depth of the seat 4) can be adjusted.

  As shown in FIGS. 1 and 2, a back frame 12 is connected to the base 3 so as to be able to tilt backward, and a backrest 5 is attached to the back frame 12. The back frame 12 is configured to be separated into a front back frame 13 connected to the base 3 and a rear back frame 14 to which the backrest 5 is attached, both of which are fitted to each other and fixed with screws. The front back frame 13 has a forward arm portion 13 a that extends forward at an outer position of the base 2, and the front end portions of the left and right arm portions 13 a are connected to the base 3 by a laterally long first shaft 16. Accordingly, the backrest 5 tilts around the axis of the first shaft 16.

  The chair of the present embodiment is a synchro-type chair in which the seat 4 is retracted in conjunction with the backward tilt of the backrest 5, and the front portion of the intermediate bracket 6 is connected to the base 3 so as to be movable back and forth. At the same time, the rear portion of the intermediate metal fitting 6 is connected to a bracket portion 17 projecting upward from the front back frame 13 by a horizontally elongated second shaft 18.

  As a means for connecting the front portion of the intermediate fitting 6 to the base 3, a pair of left and right sliders 19 are attached to the intermediate fitting 6, while a left and right slider receiver 21 is fixed to the base 3 via a support fitting 20. The slider receiver 21 is mounted so that it can be moved back and forth but not vertically. Inside the base 3, there are arranged a group of members such as a reaction force adjusting device that elastically supports the rearward tilt of the backrest 5 and a gas cylinder 22 for adjusting the rearward tilt angle of the backrest 5. Since there is no direct relationship with the invention, the description is omitted.

(2). Configuration of Seat Next, the seat 4 will be described mainly with reference to FIGS. The seat inner shell 8 constituting the seat 4 is a molded product made of a resin such as polypropylene. For example, as shown in FIG. 5, a main support portion 8a on which a body pressure of a seated person acts strongly, and a main support portion 8a The rear support portion 8b is located behind the main support portion 8a, and the front support portion 8d is located in front of the main support portion 8a. The front support portion 8d is provided with the above-described deformation allowing portion 8c. Roughly speaking, the main support portion 8a occupies a little less than half of the front-rear length, and the rear support portion 8b and the front support portion 8d occupy a range of about a quarter or more.

  The seat inner shell 8 is gently curved in an upwardly concave shape when viewed from the front, and is gently inclined so as to increase in height as it goes rearward in the longitudinal side view. In addition, a group of ribs extending vertically and horizontally are projected upward on the upper surface of the rear support portion 8b in order to ensure rigidity.

  A large number of slits 24 are formed in the main support portion 8 a of the seat inner shell 8. The slit 24 is a group of a center slit that is located in the middle of the left and right and that is long in the front and rear, an intermediate slit that is arcuate in plan view formed on the outside, and a side slit that is located outside the intermediate slit and extends in the front and back direction. It is configured. In addition, the main support portion 8a and the rear support portion 8b are connected to only the left and right side portions, and left and right laterally elongated grooves 27 are formed therebetween. For this reason, the main support portion 8a is allowed to sink downward and be deformed by the body pressure of the seated person.

  For example, as shown in FIGS. 6 and 7, the front support portion 8d of the seat inner shell 8 is formed with four rows of horizontally long front slits 28 except for the front end portion 8e. A portion between 28 is a horizontally long support bar portion 29. Due to the presence of the group of the front slits 28, the front support portion 8 d can be deformed from a posture extending linearly in a side view as shown in FIG. 7 to a posture wound downward as shown in FIG. 8.

  Between the left and right ends of the support bar portions 29 adjacent to each other in the front and rear, the left and right end portions of the support bar portion 29 positioned at the front end, the left and right end portions of the front end portion 8e, and the support bar portion 29 positioned at the rear end The left and right end portions of the main support portion 8a are connected to the left and right end portions of the main support portion 8a by mountain-shaped bridge portions 20 protruding upward in a side view. The bridge portion 20 protrudes upward from the upper surfaces of the support bar portion 29 and the front end portion 8e. Moreover, the bridge part 20 is a form which curved the board, Therefore, it crushes and deform | transforms so that a bellows may shrink.

  The support bar portion 29 has a trapezoidal cross-sectional shape opened upward, and a plurality of reinforcing ribs 31 are formed at appropriate intervals inside. Therefore, the support bar portion 29 itself has a high support function. A number of reinforcing ribs 32 are provided on the front end 8e. Therefore, the front end 8e itself has high rigidity.

  As shown in FIGS. 5 and 7, five grooves 33 arranged in the front-rear direction are formed in a portion of the cushion 9 that overlaps the deformation allowing portion 8 c of the seat inner shell 8. A deformation allowing portion 9b is formed in the front portion 9a. Due to the presence of the groove 33, a protrusion 34 is formed between the grooves 33 adjacent to each other in the front-rear direction. The groove 33 has a substantially inverted V shape in which the groove width gradually increases as it goes down. Therefore, the cross-sectional shape of the protrusion 34 is an inverted trapezoid whose width gradually decreases downward. ing. Of course, the groove 33 can also be a square or a U shape.

  As can be understood from FIG. 5, the group of grooves 33 is provided on both the left and right sides of the cushion 9 with the left and right intermediate portions interposed therebetween. For this reason, the left and right intermediate portions of the front portion of the cushion 9 are thick portions 35 where the grooves 33 do not exist. Although there are five grooves 33, they are inclined at a slight angle with respect to the horizontally long line in plan view. Precisely, the grooves 33 and the ridges 34 are inclined at a slight angle so as to be shifted toward the front as the distance from the center line 36 of the cushion 9 increases. On the other hand, the support bar portion 29 extends in parallel with a horizontally long line (a line perpendicular to the center line 36 in plan view). Therefore, the protrusion 34 is always held in a state of being placed on the support bar portion 29, and the groove 33 can be prevented from fitting into the support bar portion 29 due to the body pressure of the seated person.

  Further, the groove 33 in the foremost row is only about half as long as the middle groove 33 (33a) so that each groove 33 and the protrusion 34 can be accommodated in the area of the deformable portion 9a having a rectangular shape in plan view. However, the groove 33 (33b) in the last row is only about half as long as the intermediate groove 33 and is located far from the center line 36. . In addition, although there are five grooves 33 in total, the cutting positions in FIGS. 7 and 8 are shifted to the left and right, so that only four grooves 33 are displayed.

  The cushion 9 is not provided with the thick portion 35, and the groove 33 is formed so as to extend to the vicinity of both left and right ends of the cushion 9, or conversely, a plurality of thick portions 35 are provided on the left and right. It is also possible to divide the groove 33 into three or more on the left and right.

  As shown in FIG. 7, the ridge 34 of the cushion 9 is placed on the support bar portion 29 of the seat inner shell 8 from above, but the thick portion 35 exists and the ridge 34 is flat. By being inclined with respect to a line orthogonal to the center line 36 as viewed, the protrusion 34 is reliably held in a state where it is placed on the support bar portion 29, and the protrusion 34 fits into the front slit 28. I will not put it. Therefore, as shown in FIG. 8, when the sliding outer shell 11 is retracted and the front end 8e of the seat inner shell 8 is pulled backward, the seat inner shell 8 and the cushion 9 are wound together downward without being bitten together. It is. That is, the front part of the seat 4 can be wound without any trouble.

  As shown in FIG. 5, the left and right sides of the group of grooves 33 and protrusions 34 on the lower surface of the front portion of the cushion 9 are side recesses 37 into which the bridge portion 20 of the seat inner shell 8 is fitted. In other words, the left and right end portions of the ridge 34 are cut off to form side recesses 37 that allow the bridge portion 20 to be contracted and deformed. Accordingly, the side recess 37 communicates with the groove 33. The bridge portion 20 can also be provided at, for example, the left and right intermediate portions. In this case, a bridge portion relief recess may be formed in the left and right intermediate portions of the cushion 9.

(3) Seat outer shell Next, the structure of the seat outer shell 7 will be described mainly with reference to FIG. The fixed outer shell 10 and the sliding outer shell 11 constituting the seat outer shell 7 are molded products made of a resin such as polypropylene. As can be understood from FIGS. 4 and 7, the front end of the fixed outer shell 10 extends to the rear part of the deformation allowing portion 8c in the seat inner shell 8 (in FIG. 8, the main support portion 8a of the seat inner shell 8 is extended. (The slit is omitted.) That is, the fixed outer shell 10 overlaps with the main support portion 8a and the rear support portion 8b of the seat inner shell 8 in plan view, and at the rear portion of the deformation allowing portion 8c (front support portion 8d) of the seat inner shell 8. It has a length that overlaps partially.

  For example, as can be understood from FIGS. 4 and 9, the fixed outer shell 10 is gently curved so as to be concave upward at the front, and the rear portion is inclined rearwardly upward. A large number of rib groups are formed on the upper surface of the fixed outer shell 10 in order to increase the rigidity. The fixed outer shell 10 is formed with a hole 40 that allows the main support portion 8a of the seat inner shell 8 to sink greatly.

  For example, as shown in FIG. 9, the sliding outer shell 11 includes a base portion 11 a having substantially the same left and right lateral width as the fixed outer shell 10, and an arm portion 11 b protruding rearward from the left and right side portions of the base portion 11 a. And have. Even when the base portion 11a is fully advanced, the rear portion always overlaps the fixed outer shell 10 from above, and when the base portion 11a is fully retracted, almost the entire base portion 10a overlaps the fixed outer shell 10. The arm portion 11b always overlaps the fixed outer shell 10 from above.

  The base 11a of the sliding outer shell 11 is basically plate-shaped (may be lattice-shaped), and reinforcing ribs are formed on the upper surface so as to extend vertically and horizontally. As shown in FIG. 6, a plurality of first-view T-shaped first guide protrusions 41 having a head projecting from the front end portion of the fixed outer shell 10 are provided on the base 11 a of the sliding outer shell 11. Is formed with a longitudinal guide elongated hole 42 in which the first guide protrusion 41 cannot be removed and fits freely in the longitudinal direction. The first guide protrusion 41 and the guide elongated hole 32 are formed as a pair of left and right.

  As can be understood from FIG. 6, the rear end portion of each guide slot 42 is a wide portion 42 a into which the head of the first guide protrusion 41 is fitted and detached. For this reason, by inserting the guide long hole 42 into the first guide protrusion 41 from the location of the wide width portion 42a and then sliding the slide outer shell 11 backward, the slide outer shell 11 is held so as not to be detached.

  As shown in FIG. 9, a front-reverse L-shaped second guide protrusion 43 having a long guide plate on the front and rear is provided on the inner side of the first guide protrusion 41 in the fixed outer shell 10. The outer shell 11 is provided with a holding portion 44 for holding the second guide protrusion 43 from below. The sliding outer shell 11 is also held by the fixed outer shell 10 so as to be movable back and forth so that it cannot be pulled upward by the fitting of the second guide protrusion 43 and the holding portion 44.

  Further, as shown in FIG. 9, an upper guide rail 45 that is long in the front and rear direction is formed on the lower surface of the arm portion 11b, and an inner side of the upper guide rail 45 is an upper guide groove 46, while a fixed outer shell. 10, a lower guide groove 47 into which the upper guide rail 45 is slidably fitted and a lower guide rail 48 into which the upper guide groove 46 is fitted are formed. By fitting the upper and lower guide rails 45, 48 and the guide grooves 46, 47, the arm portion 11b is stably and smoothly supported. Further, as shown in FIG. 9, the fixed outer shell 10 is provided with a reverse holding L-shaped holding portion 49 for preventing the arm portion 11b from separating upward.

  Adjustment of the front-rear position of the sliding outer shell 11 is performed by a lever device 51 shown in FIG. Although not described in detail, the lever device 51 is attached to the right side portion of the sliding outer shell 11, and includes a lever 52 that slides in the front-rear direction and a stopper 53 that moves back and forth by the front-rear slide operation of the lever 53. Yes. The stopper 53 has a locking portion 53a protruding downward, and the fixed outer shell 10 has a plurality (three) of locking recesses 54 into which the locking portion 53a is fitted and removed. Therefore, the front-rear length of the seat 4 is adjusted in three stages.

  A mounting hole 55 for mounting the lever device 51 is provided on the right side of the sliding outer shell 11. When the stopper 53 of the lever device 51 is fitted in the lock recess 54 at the rear end, the slide type outer shell 11 is held so as not to move forward. Therefore, when the lever device 51 is attached, the sliding outer shell 11 is held so that it cannot be removed forward.

(4) Relationship between the seat inner shell and the seat outer shell Next, the field relationship between the seat outer shell 7 and the seat inner shell 8 will be described with reference to FIGS.

  As shown in FIG. 10, a rail-like side rail portion 59 that is long in the front and rear directions is formed in a portion near the left and right side edges of the fixed outer shell 10 and substantially in the rear half portion. A support rib 60 provided on the main support portion 8a of the seat inner shell 8 is placed. An outward side projection 61 is provided in the middle of the front and rear sides of the side rail portion 59 of the fixed outer shell 10, while the side projection 61 is disposed on the outer side of the support rib 60 in the main support portion 8 a of the seat inner shell 8. A side stopper 62 for embedding is formed. Thereby, the seat inner shell 8 is held so as not to move left and right and to move upward.

  As shown in FIG. 10, the left and right rear portions of the fixed outer shell 10 are provided with hook-shaped rear engagement claws 63 formed with a bifurcated upper portion, while the rear support portion 8 b of the seat inner shell 8 has a rear support portion 8 b. A rear engagement hole 64 that fits and engages with the engagement claw 63 from above is formed. The rear engagement hole 46 is engaged with the rear engagement claw 45 by shifting the seat inner shell 8 over the fixed outer shell 10 and then moving backward (the same applies to the relationship between the side stopper 62 and the side protrusion 61). .)

  As shown in FIG. 10, a pair of left and right center stoppers 64 project downward from the rear support portion 8b of the seat inner shell 8 near the left and right middle portions, while the fixed outer shell 10 has a center stopper. A pair of left and right center engaging holes 65 into which 64 is fitted are provided. Due to the fitting of the center stopper 64 and the center engaging hole 65, the seat inner shell 8 is held so as not to move forward.

  The connection structure of the sliding outer shell 11 and the seat inner shell 8 is shown in FIG. That is, on the front end portion 8e of the seat inner shell 8, the support shafts 66 are integrally formed via the left and right downward bracket portion pieces 65 at two positions near the left and right ends, while the sliding outer shell 11 has a front end at the front end. A bowl-shaped bearing portion 67 into which the support shaft 66 fits from above is provided integrally. The support shaft 66 and the bearing portion 67 can rotate relative to each other.

  Therefore, as can be understood from FIG. 8, when the sliding outer shell 11 is retracted, the front end portion 8e of the seat inner shell 8 is pulled backward, and accordingly, the seat inner shell 8 and the cushion 9 The deformation allowing portions 8c and 9a are bent and deformed, and the front portion 8e of the seat inner shell 8 and the front portion of the cushion 9 are wound downward. Thereby, the front-end position (depth of a front end) can be adjusted by changing the front-end position of the seat 3. As shown in FIG. 8, the support shaft 67 and the bearing portion 68 are located below the upper surface of the sliding outer shell 11.

  As can be easily understood from FIG. 8, in this embodiment, the support shaft 67 and the bearing portion 68 are moved backward without changing the height, and the front of the seat inner shell 8 and the cushion 9 are moved along with this backward movement. The parts 8e and 9a are wound downward. Therefore, the front part of the seat 4 can be rolled up compactly. As described above, since the protrusion 34 of the cushion 9 is placed on the support bar portion 29 of the seat inner shell 8, the deformation allowing portion 9b of the cushion 9 and the deformation allowing portion 8c of the seat inner shell 8 mesh with each other. Without being troubled, it is possible to wrap around in a compact manner.

(5). Relationship between intermediate metal fitting and seat outer shell Next, the relationship between the intermediate metal fitting 6 and the seat outer shell 7 will be described mainly with reference to FIG. As shown in FIG. 12, the intermediate fitting 6 has a shape close to a substantially T shape in which the front side swells to the left and right in a plan view, and a wall is formed around it. Further, the top plate 69 is formed with a substantially punched hole 70 in a plan view (this hole 70 is for fitting the gas cylinder 22 shown in FIG. 3).

  On the other hand, the fixed outer shell 10 is formed with a recess 71 having a downward opening into which the intermediate metal fitting 6 fits completely. A pair of left and right front stoppers 74 are provided at the lower ends of the left and right end portions of the front wall 72 constituting the recess 71 in the fixed outer shell 10 so as to wrap the front corner portion of the front plate 73 of the intermediate bracket 6 from below. The front engaging claw 75 that holds the front plate 73 of the intermediate metal fitting 6 so as not to face backward is provided at the front left and right intermediate portions of the upper bottom surface of the recess 71.

  Further, the front plate 73 of the fixed outer shell 10 is provided with a pair of left and right front engaging claws 76. As shown in FIG. 3, the front plate 62 of the intermediate metal fitting 6 is provided with a pair of left and right front engagement holes 77 into which the front engagement claws 76 are fitted. A fitting relationship between the front portion of the intermediate metal fitting 6 and the front stopper 74 and the front engaging claw 76 is indicated by an arrow A.

  Further, three rear engaging pieces 78 are formed on the rear end portion of the upper surface plate 69 of the intermediate metal fitting 6 so as to project toward the cutout hole, while the rear end edge of the cutout hole 40 in the fixed outer shell 10 is formed. A downward weir portion 79 is formed at this location, and three rear engagement holes 80 are provided in the rear plate of the weir portion 79 so that the rear engagement pieces 78 can be fitted from behind. The fitting relationship between the rear engagement piece 78 and the rear engagement hole 80 is indicated by an arrow B.

  The fixed outer shell 10 is placed on the intermediate metal fitting 6 while being shifted slightly forward from the predetermined position, and then pushed backward while being pressed downward on the intermediate metal fitting 6, the intermediate outer shell 6 is set. In the process of this attachment, the front engaging claw 75 once escapes upwards against the elasticity and then returns to its original state. Then, the fixed outer shell 10 is held so as not to be able to move forward and to be lifted upward.

(6). Others The present invention can be embodied in various ways other than the above-mentioned protrusions. For example, the form of the seat inner shell can be arbitrarily set as required. The fixed portion of the seat inner shell can be configured separately from the deformable portion. Further, the member that supports the seat inner shell is not necessarily the seat outer shell, and may be a support member having a frame structure, for example. As a means for providing the deformation allowing portion in the seat inner shell, a thin hinge portion can be adopted instead of forming the slit. Moreover, although it remove | deviates from a claim, the above-mentioned structure can also be applied to the backrest which can change height.

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

3 seat 7 seat outer shell 8 seat inner shell 8a seat inner shell main support portion 8b seat inner shell rear support portion 8c seat inner shell deformation allowance portion 8d seat inner shell front portion 8e seat inner shell front end portion 9 cushion 9a Front part 9b Cushion deformation allowable part 10 Fixed outer shell 11 Slide outer shell 28 Front slit constituting the deformation allowable part 29 Support bar part 33 Groove 34 Projection 35 Thick part 37 Side recess 66 Support shaft 67 Bearing part

Claims (4)

The seat has a structure in which a cushion is disposed on the upper surface of the seat inner shell, and a deformation permitting portion is formed on the front portion of the cushion and the seat inner shell so that the front portion can be wound downward. The seat inner shell and the front part of the cushion are wound downward to reduce the longitudinal length of the seat,
The deformation-allowing portion of the cushion is configured by forming a plurality of strips by arranging a horizontally elongated groove that opens downward in the front-rear direction. Therefore, a portion between the adjacent grooves in the front-rear direction is a horizontally elongated projection. It is a strip, and the deformation allowing portion having the protrusion is placed on the deformation allowing portion of the seat inner shell from above,
Chair. The front portion of the seat inner shell is allowed to be deformed by forming a plurality of laterally elongated slits so as to be lined up in the front and rear, and a portion between the slits adjacent to each other in the front and rear is a protrusion of the cushion. It is a horizontally long support bar part on which the strip is placed,
The chair according to claim 1. The protrusions and grooves and the support bar are in a non-parallel posture in plan view,
The chair according to claim 2. The seat inner shell is supported by a seat outer shell, and the seat outer shell is mounted so that the slide seat outer shell that supports a deformation allowing portion of the seat inner shell and the slide seat outer shell are movable back and forth. Separated into a fixed seat outer shell,
The chair as described in any one of Claims 1-3.

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