JP2013094580A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair including a lumbar support that is capable of comfortably supporting the lumbar region by stably supporting and smoothly vertically moving a lumbar support body and vertically moving the lumbar support with a moving track along the curved part even when the lower part of a back frame is curved to be projected to the front.SOLUTION: The lumbar support 10 of the chair includes a lumbar support body 41 in the horizontal direction, and four attaching part 42 provided on both sides of the lumbar support body 41 so as to be separated in the vertical direction. The upper right and left attaching parts 42 are supported movably to an oblique back upper part by a guide part above the curved part in a pair of right and left side frame rods 19, and the lower right and left attaching parts 42 are supported movably to an oblique front upper part by a guide part below the curved part.

Description

  The present invention relates to a chair in which a lumbar support is attached to a backrest so as to be movable in the vertical direction.

  As a chair with a lumbar support attached to the backrest, the lumbar support has a body part that faces in the left-right direction, a pair of left and right connecting parts that hang down from the lower ends of both side parts, and outward from the lower side edge of both connecting parts. A gripping portion that extends to the back of the back frame (backrest body), with both gripping portions penetrating both sides of the back frame (backrest body) and supported so that the vertical position can be adjusted (see, for example, Patent Document 1), lumbar support The left and right sides of the rear surface of the main body part are composed of a main body part facing left and right, and a pair of left and right operation parts that are suspended from the lower ends of both side parts, and a knob part facing the outer side at the lower end. From the lower center part of the back frame (back frame), which is supported by a bracket provided on the inner surface of the left and right side members of the back frame (back frame) so that the vertical position can be adjusted (see, for example, Reference 2) Lumber standing There is a support support portion in which the center portion in the left-right direction of the lumbar support main body is attached so that the vertical position can be adjusted (see, for example, Patent Document 3).

JP 2008-119217 A Japanese Patent No. 4575233 Japanese Patent No. 4133067

  The lumbar support of the chair described in Patent Documents 1 and 2 is supported by the left and right sides of the back frame only at two left and right sides, and the lumbar support described in Patent Document 2 is a lumbar support that stands up from the back frame. Since the support is supported at only one central portion in the left-right direction, when the left and right grips are operated to adjust the vertical position of the lumbar support, force is applied uniformly to the left and right grips. If the lumbar support is not moved up and down, the lumbar support may sway in the left-right direction and may not be able to move up and down smoothly.

  Further, if only the left and right portions of the lumbar support are supported by the left and right sides of the back frame so that the vertical position can be adjusted, the vicinity of the back frame that supports the waist is projected forward as described in Patent Document 1. When it is bent to the curved portion, it is difficult to provide members that support both side portions of the lumbar support in the curved portion. Therefore, as described in Patent Document 1, members that support the left and right gripping portions of the lumbar support are generally provided in a straight portion below (or above) the curved portion of the back frame.

  As described above, when the members that support both side portions of the lumbar support are provided on the straight portion of the back frame, the movement locus of the lumbar support becomes only one direction, that is, the vertical direction, and becomes linear. For this reason, the lumbar support cannot be moved up and down along the curved portion of the back frame, and the rear surface of the lumbar part may strike the front surface of the lumbar support, which may cause discomfort to the seated person.

  The present invention has been made in view of the above problems, and stably supports the lumbar support main body so that the lumbar support body can be moved up and down smoothly, and the lower portion of the back frame is curved so as to protrude forward. Even so, an object of the present invention is to provide a chair provided with a lumbar support in which the lumbar support can be moved up and down with a movement locus along the curved portion so that the waist can be comfortably supported.

According to the present invention, the above-mentioned problems are solved as follows.
(1) The lower portions of the pair of left and right side frame ridges in the back frame are curved so as to protrude forward in a side view, and the left and right pair of side frame ridges in the vicinity of the curved portion, both sides of the lumbar support The lumbar support includes a lumbar support main body facing in the left-right direction, and four attachment portions spaced apart in the vertical direction provided on both sides of the lumbar support main body. The upper left and right mounting parts are guided obliquely and upwardly by a guide part above the curved part in the pair of left and right side frame rods, and the lower left and right mounting parts are The guide portion below the bending portion is guided so as to be movable obliquely forward and upward.

With such a configuration, the movement trajectory of the lower and upper parts of the lumbar support body can be made different. When the lumbar support body is moved upward, the lower part of the lumbar support body is directed diagonally forward and upward from below. Similarly, the upper part moves from the lower side to the upper side obliquely rearward.
As a result, when adjusting the vertical position of the lumbar support body, it can be moved with a movement trajectory along the curved portions of the left and right side frame ridges, so that the rear surface of the lumbar portion of the seated person strikes the lumbar support body. It is possible to comfortably support the lower back without feeling uncomfortable.
In addition, the lumbar support main body is stably supported at four points on the left and right side frame ridges by the four mounting portions provided on both sides thereof, so that the lumbar support main body can be smoothly prevented from wobbling in the left-right direction. Even if the lumbar support main body bends backward, a torsional load is not applied to the mounting portion.

(2) In the above item (1), a guide hole in the vertical direction is provided in the guide part below the curved part in the left and right side frame ridges, and the gripping part provided on the operation member is provided in the side frame by the guide hole. It protrudes from the outer side surface of the collar, is supported so as to be movable in the vertical direction, and the inner part protruding inward from the guide part of the operation member is linked to the lower left and right attachment parts.

  With such a configuration, the operation member supported by the guide hole provided in the guide portion below the curved portion of the side frame rod is linked to the left and right mounting portions, and the grip portion of the operation member is moved to the side. Since it protrudes from the outer surface of the frame rod, the position of the hand operating the operating member in the seated state is shifted downward, and the operability of the operating member is improved.

(3) In the above item (2), the lower mounting portion includes a rearward piece, and the rearward piece is linked to the inner end of the operation member facing in the left-right direction so as to be detachable from the front.

  With such a configuration, it is possible to easily perform the link operation between the lower mounting portion of the lumbar support main body and the operation member from the front of the side frame rod.

(4) In any one of the above items (1) to (3), the left and right widths of the lumbar support main body are substantially equal to the dimension between the opposing surfaces of the left and right side frame rods, and the four attachment portions are connected to the lumbar. It protrudes outward from both side edges of the support body and is supported by the guide portions of the side frame rods.

  With such a configuration, the entire lumbar support body is easily elastically deformed rearward, and the effective support area for supporting the rear surface of the waist is increased, so that the entire waist can be comfortably supported.

(5) In any one of the above items (1) to (4), a vertical groove is provided on the front surface above the curved portion of the side frame so as to open forward, and the upper portion is mounted in the groove. A guide member that supports and guides the portion so as to be movable in the vertical direction is mounted so as to be detachable from the front.

With such a configuration, the upper mounting portion can be easily supported by the side frame rod and guided in the vertical direction only by mounting the guide member in the concave groove of the side frame rod.
Moreover, attachment / detachment of the upper attachment part to the side frame can be easily performed from the front.

  According to the present invention, the lumbar support main body is stably supported so that it can be smoothly moved up and down, and even if the lower portion of the back frame is curved so as to protrude forward, it follows the curved portion. It is possible to provide a chair provided with a lumbar support in which the lumbar support can be moved up and down along the movement locus so that the waist can be comfortably supported.

It is a front view which shows one Example of the chair of this invention. Similarly, it is a side view. It is a perspective view of a back frame and a lumbar support attached to the back frame. Similarly, it is a front view. Similarly, it is a side view. It is a disassembled perspective view of a back frame, the lumbar support main body with which it is mounted | worn, and a backrest support body. It is a disassembled front view of a lumbar support main body, a backrest support frame, and a cover member and an operation member attached thereto. It is an expansion disassembled perspective view of the side edge part of a lumbar support main body, a cover member, and an operation member. It is an expansion perspective view before mounting | wearing with the upward piece of a cover member, and the operation member with which it is mounted | worn. Similarly, it is an enlarged perspective view after mounting. It is the XI-XI line expansion transverse end view of FIG. Similarly, it is an XII-XII line enlarged transverse end view. It is the XII-XII line enlarged vertical front view of FIG. It is an expansion perspective view of the engaging part of an engaging recessed part and a connection member. FIG. 4 is an enlarged perspective view of a side frame rod and a guide member attached thereto. It is the XVI-XVI line expansion vertical side view of FIG. Similarly, it is an XVII-XVII line enlarged transverse end view.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a chair provided with the lumbar support of the present invention, and FIG. 2 is a side view of the same.
The chair has a leg 3 having five radial rods 2 each having a caster 1 at the tip, and a telescopic member that is erected at the center of the leg 3 and accommodates a gas spring (not shown). A vertical pillar 4, a front base 5 with the rear end fixed to the upper end of the base 4, a seat 6 supported by the base 5, and a shaft 7 with the front end facing the left-right direction A back support 8 pivotally attached to the support base 5, a back rest 9 supported on the rear upper part of the back support 8, and a lumbar support 10 provided at an intermediate portion in the vertical direction of the back support 9, It has.

  The support base 5 has a substantially rectangular box shape in a plan view that is long in the front-rear direction with the opening of the upper surface closed by a cover, and the backrest is always directed forward via a backrest support 8 inside. The urging means for urging the urging force and the adjusting means for adjusting the urging force of the urging means (both not shown) are accommodated. In addition, since such an urging | biasing means and adjustment means are not directly related to this invention, those specific structures and detailed description are abbreviate | omitted.

The backrest support 8 includes a lateral frame 11a and a pair of left and right upright frames 11b and 11b connected to both end portions thereof. It consists of a pair of left and right backrest support ridges 12 and 12 facing in the front-rear direction, the rear end portion of which is fixed to the horizontal frame 11a of the sag support frame 11, and they are made of, for example, aluminum or an alloy thereof (see FIG. 3, 4, and 7, the backrest support is not shown).
The horizontal frame 11a is gently curved in an arc shape so that a central portion in the left-right direction protrudes rearward in a plan view, and both side portions are inclined obliquely upward in a front view. The left and right standing frames 11b are inclined obliquely forward and upward so as to face the same direction as the lower part of the side frame rod 19 of the back frame 17 described later.

The left and right backrest support rods 12 are inclined forward and downward, and the center portion is gently curved downward.
The front end portions of the left and right backrest support rods 12 are pivotally attached to both side portions of the support base 5 so as to be rotatable in the vertical direction by the shaft 7.

The rear ends of the left and right backrest support rods 12 are fixed to the horizontal frame 11a of the backrest support frame 11 as follows.
First, the rear end portions of the left and right backrest support rods 12 are formed in a pair of left and right fitting holes 13 and 13 (see FIGS. 4 and 7) formed on the left and right sides of the horizontal frame 11a. Fits without any problem.
Next, bolts 15 and 15 are inserted from above into two mounting holes 14 and 14 provided on the upper surface at positions corresponding to the left and right fitting holes 13 in the horizontal frame 11a, and the lower ends of both bolts 15 are The backrest support rod 12 is tightened by being screwed into two left and right female screw holes 16, 16 provided at the rear end of the backrest support rod 12. As a result, the backrest support 8 is formed on the lateral frame 11a of the backrest support frame 11 in which the rear end portions of the left and right backrest support rods 12 are firmly fixed.

  The backrest 9 includes a back frame 17 made of a hard synthetic resin having a substantially rectangular frame shape in front, and a tension member 18 stretched on the surface of the back frame 17, that is, the front surface (FIGS. 3 to 6). In FIG.

  As shown in FIGS. 3 to 6, the back frame 17 has a pair of left and right side frame rods 19 that are curved in a gentle arc shape so that a portion slightly below the center in the vertical direction protrudes forward in a side view. , 19 and the upper ends of the upper frame ridges 20 are connected to each other, and the upper frame ridge 20 that is curved in a gentle arc shape so that the central portion in the left-right direction protrudes rearward in plan view, and the lower ends of the side frame ridges 19, 19 A lower frame rod 21 that connects the portions substantially linearly, and tension members 22 and 23 of a tension member 18 that are attached to the front surface and both side end portions of the lower frame rod 21 with bolts 28 and nuts 30. Yes. The portions below the curved portion C of the left and right side frame collars 19 are inclined in the same direction as the upright frame 11 b of the backrest support frame 11.

  As shown in FIGS. 3 and 4, concave grooves 24 that open forward are formed along the longitudinal direction on the front surfaces of the left and right side frame rods 19, 19 and the lower frame rod 21. The groove width of the concave groove 24 of the both side frame rods 19 is gradually increased downward from the central portion in the vertical direction (see FIG. 4), and the concave groove 24 is a curved portion of the side frame rod 19 In the vicinity of C, it is partitioned by lateral ribs 25, 25 that are spaced apart vertically.

  The front and rear dimensions of the inner piece 19a and the outer piece 19b facing each other across the concave groove 24 in the both side frame rods 19 are such that the front edge of the outer piece 19b protrudes more forward than the front edge of the inner piece 19a. The longitudinal dimension of 19b is made larger than that of the inner piece 19a (see FIG. 17).

  As shown in FIG. 6, the left and right upright frames 11b of the backrest support frame 11 described above are fitted to the outer side surfaces of the left and right side frame rods 19, 19 below the curved portion C. A fitting recess 26 is formed in the opening.

  In order to attach the back frame 17 to the back support frame 11, first, the fitting recesses 26 provided in the left and right side frame rods 19, 19 are fitted into the left and right standing frames 11b, 11b of the horizontal frame 11a from above. At the same time, the lower frame 21 of the lower frame 17 of the back frame 17 is brought into contact with the upper surface of the horizontal frame 11 a, and the back frame 17 is temporarily supported by the back support frame 11.

  Next, the bolts 28 and 28 inserted into the pair of left and right mounting holes 27 and 27 provided in the back surface of the fitting recess 26 of the left and right standing frames 11b and the left and right side frame rods 19 are connected to the left and right side frames. At the lower part in the concave groove 24 of the flange 19, it is screwed and tightened to the square nuts 30 and 30 fitted to the upper and lower nut holding parts 29 and 29 provided on the inner surface of the inner piece 19a. The lower part of the collar 19 is fixed to the left and right standing frames 11b (see FIG. 13).

  Next, the bolts 32 and 32 inserted from below into a pair of left and right mounting holes 31 and 31 provided at the center in the left and right direction of the horizontal frame 11a are rotated by ribs in the concave groove 25 of the lower frame rod 21. The fixed square nuts 30 and 30 are screwed and tightened to fix the lower frame rod 21 and the horizontal frame 11a. As a result, the back frame 17 is firmly fixed to the backrest support frame 11 with the lower part thereof fitted into the backrest support frame 11.

After fixing the back frame 17 to the backrest support frame 11, cover members 33, 33 are fitted on the outer surfaces of the left and right standing frames 11b, 11b.
As shown in FIGS. 6 to 8, the cover member 33 includes a vertically long plate-shaped upward piece 34 having a slightly larger thickness in the left-right direction except for the upper end portion, and a back support frame at the lower end thereof. 11 and an inwardly facing piece 35 inclined obliquely inward and downward, which is provided so as to follow the inclined surface of the lower surface of both side parts. A stop piece 36 projects inwardly. Note that the upward piece 34 and the above-described standing frame 11b to which the upward piece 34 is attached move the upper and lower attachment portions 42 of the lower portion of the lumbar support main body 41 described later through the operation member 43 described later and the operation member 43 described later. It also serves as a guide part for supporting and guiding it so as to be movable in the direction.

At the upper end of the upward piece 34, there is an inward and upward locking claw 34 a, at the inner end of the inward piece 35, there is a downward locking claw 35 a, and the locking piece 36 has a backward locking claw 36 a, Each is protruding.
On the outer side surfaces of the left and right standing frames 11b and the upper side of the horizontal frame 11a in the back support frame 11, a concave portion 37 is formed in the vertical direction, which complements the cover member 33 and whose upper half penetrates inside and outside. ing.

To attach the cover member 33, the cover member 33 is fitted into the recess 37 formed in the back support frame 11, and the locking claw 34 a at the upper end of the upward piece 34 is, as shown in FIG. The side frame collar 19b is locked to the inner surface of the downwardly facing piece 38 of the upper edge of the fitting recess 26 and, as shown in FIG. 11, is locked to the left and right through hole 39 provided near the base of the standing frame 11b. The piece 36 is fitted, the locking claw 36a at the tip thereof is elastically engaged with the locking step 40 at the back of the through hole 39, and the downward locking claw 35a of the inward piece 35 is It engages with a locking step (not shown) provided at the lower end of 37.
As a result, the cover member 33 is attached to the concave portion 37 formed on the outer side surface of the back support frame 11 so as to cover the heads of the upper and lower bolts 28 to which the back frame 17 is fixed. It can also be removed.

  As shown in FIGS. 3, 4, 7, and 8, the lumbar support 10 includes a synthetic resin lumbar support body 41 that can be elastically deformed moderately in the front-rear direction, upper left and right side edges, and both side edges. And four left and right mounting portions 42 that protrude outwardly so as to be located on the diagonal line of the lumbar support main body 41 at the left and right corners where the lower edge and the lower edge intersect, A pair of left and right operation members 43 linked to the left and right mounting portions 42 are provided, and are mounted in the vicinity of the curved portion C of the left and right side frame rods 19 so as to be movable in the vertical direction. Each mounting portion 42 is composed of a short outwardly facing piece 42a facing outward and a backwardly facing piece 42b continuously provided at the tip thereof. Note that the pair of left and right upper mounting portions 42 are continuously provided slightly below the upper end of the lumbar support main body 41.

  In plan view, the lumbar support body 41 is gently curved in an arc shape so that the central portion in the left-right direction protrudes backward, and is gently curved in an arc shape so that the lower edge of the central portion protrudes upward. Thus, the vertical dimension is gradually reduced from the left and right ends toward the central part, and the vertical cross-sectional shape is curved in an arc shape so that the central part in the vertical direction protrudes forward. The back frame 19 has a substantially horizontally long rectangular shape in front view which is substantially equal to the dimension between the opposing surfaces of the side frame ribs 19b.

  Operating members 43 and 43 for moving the lumbar support main body 41 in the vertical direction are mounted on the upward piece 34 serving also as the lower guide portion of the cover member 33 mounted on the lower side of the side frame rod 19 as follows. Has been. Since the cover member 33 and the operation member 43 are symmetrical and have the same mounting form, the following description will be made only on the right side.

  As shown in FIGS. 7 to 9 in an enlarged manner, the left and right operation members 43 include a grip portion 44 made of a synthetic resin and a linkage member 45 with a lumbar support body 41 made of a metal plate. An inward protruding piece 44a having a small front and rear thickness is integrally formed on the inner side surface of the grip portion 44, and the inwardly protruding piece 44a opens inward so that the outer portion of the linkage member 45 can be fitted thereto. A vertically slit fitting hole 46 is formed.

  The outer half of the inwardly projecting piece 44a and the lower part of the front half are thick, and the front and rear surfaces of the inwardly projecting piece 44a of the part where the inner and outer thick parts 47, 47 face each other are slits that face in the vertical direction. Concave grooves 48, 48 are formed (see FIG. 12).

  The linking member 45 has a vertical plate shape that is longer in the left-right dimension than the inwardly projecting piece 44a and can be slightly elastically deformed in the front-rear (plate thickness) direction. An engagement piece 45a having a small vertical dimension that can be engaged with an engagement recess 57, which will be described later, is provided so as to protrude from the tip of the linking member 45 adjacent to the engagement piece 45a. A rectangular linkage hole 49 is formed that opens in the front-rear direction in which the rear piece 42b of the lower mounting portion 42 is slidably fitted. The left and right width of the linkage hole 49 is larger than the left and right dimensions of the rear piece 42b so that the rear piece 42b can move only in the left and right direction. Is not transmitted to the operation member 43 through the rear piece 42b.

  When the outer portion of the linking member 45 is fitted into the fitting hole 46 of the inwardly projecting piece 44a, the front surface of the locking hole 50 that is formed on both front and rear surfaces of the inwardly projecting piece 44a slightly closer to the front end and communicates with the fitting hole 46. When the protrusion 51 having a low height projecting from the front surface of the central portion in the left-right direction of the linking member 45 is engaged with the one on the side, the linking member 45 is detached from the fitting hole 46 of the inward protruding piece 44a. Is to be prevented.

As shown in FIGS. 6, 8, 9, and 12, the inwardly projecting piece 44 a of the grip portion 44 is movable in the vertical direction on the upward piece 34 of the cover member 33 and the above-described standing frame 11 b. The upper and lower guide holes 52 and 52 to be fitted are formed to face each other so as to penetrate the inner and outer peripheral surfaces of the side frame collar 19 of the back frame 17, that is, in the left and right direction. On the inner opening edge excluding the lower end portion of the guide hole 52, inwardly extending ridges 53, 53 that protrude in the vertical direction are provided so as to be opposed to each other in the front-rear direction. Since the upward piece 34 is attached to the lower part of the side frame rod 19 that is inclined obliquely forward and upward, the guide hole 52 is also inclined so as to face obliquely forward and upward.
The guide hole 52 formed in the upward piece 34 and the upright frame 11b constitutes a part of the guide portion that guides the operation member 43 and the attachment portion 42 of the lower portion of the lumbar support main body 41 linked thereto. However, when the upward piece 34 and the standing frame 11b are omitted, the guide hole 52 as described above may be provided in the outer piece 19b having a thick wall frame 19.

  The dimension between the opposing surfaces of both inwardly protruding ridges 53 is substantially equal to the thickness of the thin portion 54 of the inwardly protruding piece 44a excluding the thick portions 47 and 47, and both inwardly protruding ridges 53 have inwardly protruding pieces. The concave grooves 48 on both front and rear sides of 44a are slidably fitted.

  In order to attach the operation member 43 to the upward piece 34, as shown in FIGS. 9, 10, 12, and 13, guide holes provided in the upward piece 34 and the standing frame 1b of the backrest support frame 11 are provided. The inwardly projecting piece 44a of the gripping portion 44 is fitted to the lower end portion of the gripping portion 44 from the outside until the inner side surface of the gripping portion 44 abuts or approaches the outer side surface of the upward piece 34. At the time of this fitting, the tip portion including the linking hole 49 of the linking member 45 passes through a long hole 55 that is formed in the inner surface of the fitting recess 26 of the side frame rod 19 and faces obliquely upward, and is on the side. It is located in the concave groove 24 of the frame rod 19 (see FIG. 13).

  Next, the operating member 43 is moved upward, and the concave grooves 48, 48 on both front and rear sides of the inwardly projecting piece 44 a are fitted to the front and rear inwardly protruding ridges 53, 53. Thus, the operation member 43 is prevented from being removed from the guide hole 52 and is restricted from moving in the left-right direction. In this state, the operation member 43 is guided by the inward protrusion 53 and the guide hole 52 and moved in the up-down direction. Can do. When the lumbar support main body 41 is located at the lower limit so that the operation member 43 does not come out of the guide hole 52, the operation member 43 linked to the guide member 52 is below the lower end of the inward protrusion 53. It doesn't move in. The lower limit position of the lumbar support 10 at this time is determined by a guide member 58 which will be described later, which is attached to the side frame rod 19.

  As shown in FIGS. 12 to 14, the lumbar support main body 41 and the left and right operation members 43 (only shown on the right side of the left and right symmetry) are connected to the lumbar support body 49 of the connection member 45 of the operation member 43. The left and right attachment portions 42 of the lower part 41 in 41 are connected to each other by fitting them detachably from the front. Therefore, when the left and right operation members 43 are operated in the vertical direction, the lumbar support main body 41 moves up and down in conjunction with it, and even if the lumbar support main body 41 bends in the front-rear direction, the load acts directly on the operation member 43. There is nothing to do.

  As shown in FIGS. 4, 13, and 14, in the recessed grooves 24 at the lower portions of the left and right side frame ridges 19, that is, at the depths of the recessed grooves 24 at the portions facing the upward pieces 34 attached to the side frame ridges 19. On the surface, a plate-like ridge piece 56 facing in the vertical direction is projected forward so as to be substantially orthogonal to the linking member 45 of the operation member 43. A plurality of upper and lower engaging recesses 57 that are concave in a forward-facing side view are formed at regular intervals in the vertical direction. By selectively engaging with the plurality of upper and lower engaging recesses 57 with the engagement pieces 45a protruding from the tip of the linkage member 45 of the operation member 43, the vertical position of the lumbar support 10 is adjusted step by step. It can be adjusted with a feeling.

  At this time, since the linking member 45 has a plate shape substantially perpendicular to the vertical direction, it is easily elastically deformed in the thickness direction, that is, the front-rear direction. Even if the vertical width is relatively large and the engagement force is increased, the engagement piece 45a can be selectively engaged with the engagement recess 57 with a light operation force. In addition, it is preferable that the vertical width of the engagement piece 45a and the engagement recess 57 is substantially equal so that the lumbar support 10 does not rattle in the vertical direction.

  A pair of left and right mounting portions 42, 42 on the upper side of the lumbar support main body 41 are supported so as to be movable in the vertical direction in the concave groove 24 slightly above the curved portion C in the left and right side frame rods 19, 19. Guide members 58 and 58 are mounted as follows.

  As shown in enlarged views in FIGS. 15 to 17, the left and right guide members 58 (the left and right sides of FIGS. 15 and 16 are shown symmetrically with respect to the left and right sides) so as to follow the width dimension of the concave groove 24. In addition, an inward piece 58a whose left and right dimensions are gradually narrowed upward, a rear piece 58b projecting from the outer edge thereof, and a bottom piece connected to the lower ends of the inward piece 58a and the rear piece 58b 58c, and the transverse plane has an inward L-shape. The backward piece 58b is curved in an arc shape so as to be in surface contact with the curved inner surface of the outer piece 19b of the side frame collar 19. Further, a notch 59 is provided at the lower end of the rear piece 58b so as not to interfere with the bolt 28 for fixing the back frame 17 to the back support frame 11 described above.

An engagement groove 61 having a U-shaped cross section opening inwardly and rearwardly is formed on the rear surface of the thick portion 60 connected to the upper ends of the inwardly facing piece 58a and the backwardly facing piece 58b.
In addition, a pair of upper and lower engaging protrusions 62 and 62 project outward from the front end portion of the outer surface of the rearward piece 58b.

  In order to attach the guide member 58 to the side frame rod 19, the guide member 58 is placed in the concave groove 24 of the side frame rod 19 so that the lower surface of the bottom piece 58 c abuts the upper surface of the rib 25 in the concave groove 24. First, the upper engaging groove 61 is engaged with the protrusion 64 projecting from the outer surface of the inner piece 19a of the side frame rod 19 and positioned in the vertical direction. The engaging protrusions 62 and 62 are engaged with a pair of upper and lower concave portions 63 and 63 formed on the inner surface of the front end portion of the outer piece 19 b of the side frame rod 19. As a result, the guide member 58 is mounted in the concave groove 24 so as not to be removed forward, and can be removed forward if necessary. In addition, if the front surface of the guide member 58 is in contact with the rear surface of the tension member 18 stretched on the back frame 17, it is possible to reliably prevent the guide member 58 from rattling in the front-rear direction.

  The mounting position of the guide member 58 is such that the lumbar support 10 stops at the lower limit position when the rearward piece 42b of the mounting portion 42 on the upper side of the lumbar support main body 41 comes into contact with the upper surface of the bottom piece 58c. The member 43 is also set to stop at the lower limit position where it does not leave the guide hole 52 of the upper piece 34 of the cover member 33.

  As shown in FIG. 17, the outwardly facing piece of the mounting portion 42 on the upper side of the lumbar support main body 41 is provided between the opposing surfaces of the rear surface of the inwardly facing piece 58 a of the guide member 58 and the front end of the inner piece 19 a of the side frame rod 19. A gap S slightly smaller than the thickness of 42a is formed. Accordingly, by positioning the pair of left and right mounting portions 42, 42 on the upper side of the lumbar support main body 41 in the recessed grooves 24 behind the left and right guide members 58, 58, The portion is guided by the pair of left and right guide members 58 and the inner piece 19a, and can move in the vertical direction.

  As a procedure for assembling the lumbar support 10, before the tension member 18 is stretched on the back frame 17, first, the left and right operation members 43 are attached to the lower portions of the left and right side frame rods 19 as described above.

  Next, the rear facing pieces 42b of the attachment portions 42 on both lower side portions of the lumbar support main body 41 are fitted into the linkage holes 49 of the linkage members 45 of the left and right operation members 43 so as to be slidable from the front (FIGS. 12 to 12). 14) and the rear facing pieces 42b of the left and right attachment portions 42 on both sides of the upper portion are inserted into the concave groove 24 of the side frame rod 19 from the front (see FIG. 17). At this time, as shown in FIG. 12, the rear surface of the side end portion of the lumbar support main body 41 faces the front surface of the side frame rod 19 via a required gap, and when the lumbar support main body 41 bends backward, The rear surface of the side end is in contact with the front surface of the side frame collar 19. Even if the lumbar support main body 41 bends in the front-rear direction, the rear piece 42b only slides in the front-rear direction in the link hole 49, so that the entire lumbar support main body 41 including the link member 45 is provided. The risk of bending load from is small.

  Next, as described above, the left and right guide members are moved together with the operation member 43 to the position where the operation member 43 is not detached from the guide hole 52 of the upper piece 34 of the cover member 33. 58 is mounted in the concave groove 24 of the side frame rod 19 in the manner described above (see FIG. 17).

Next, when the lumbar support body 41 is moved downward to the lower limit position where the rear piece 42b of the upper mounting portion 42 contacts the upper surface of the bottom piece 58c of the guide member 58, the assembly of the lumbar support 10 is completed. The lumbar support 10 is supported at four points by the left and right side frame rods 19 by the four attachment portions 42 provided at the upper and lower end portions on both side edges of the lumbar support main body 41. After the lumbar support 10 is assembled, as described above, the operation member 43 does not leave the guide hole 52 of the upward piece 34. Further, since the outwardly facing piece 42 a of the upper mounting portion 42 is in contact with or close to the rear surface of the inwardly facing piece 58 a of the guide member 58, the upper mounting portion 42 is not detached forward from the guide member 58.
Even after the tension member 18 is stretched on the back frame 17, the lumbar support body 41 and the guide member 58 can be mounted from the rear side of the back frame 17 by bending the tension member 18 forward. .

  When the gripping portions 44 of the left and right operation members 43 are slid in the vertical direction, the attachment portions 42 on both lower sides linked to the linking member 45 and the lumbar support main body 41 integrated therewith are interlocked in the vertical direction. The vertical position of the lumbar support 10 can be adjusted. At this time, the engagement piece 45a at the tip of the linking member 45 selectively engages with a plurality of upper and lower engagement recesses 57 of the protruding piece 56 provided in the lower groove 24 in the left and right side frame rods 19. Thus, the vertical position of the lumbar support 10 can be adjusted stepwise and with a sense of moderation.

  As described above, in the illustrated embodiment, the left-right width of the lumbar support main body 41 is substantially equal to the dimension between the opposing surfaces of the left and right side frame rods 19 and protrudes from both side edges of the lumbar support main body 41. Since the four mounting portions 42 are substantially supported by the left and right side frame rods 19, the entire lumbar support body 41 can be elastically deformed rearward, and a large effective support area for supporting the rear surface of the waist. Thus, the entire waist can be comfortably supported.

  Also, the four upper, lower, left, and right mounting portions 42 project outward from the upper and lower ends of both side edges so as to be close to the lumbar support main body 41, so that the lumbar support main body 41 bends backward. However, there is little risk of a torsional load being applied to each mounting portion 42 and the lower operation member 43, and the lumbar support main body 41 is provided on the left and right sides of the back frame 17 via the four mounting portions 42 located on the diagonal lines. Since the side frame rod 19 is stably supported at four points, the lumbar support body 41 can be smoothly moved up and down while preventing wobbling in the left-right direction.

  Further, the shape of the lumbar support main body 41 is gently curved in an arc shape so that the lower end of the central portion protrudes upward in a front view, and its vertical dimension gradually decreases from the left and right ends toward the central portion. Therefore, the center part in the left-right direction where the lumbar part (lumbar vertebra) of the lumbar support main body 41 strongly hits easily becomes bent backward, and the lumbar part can be comfortably supported without a sense of incongruity.

  The lower left and right attachment portions 42 are projected at corners where the lower edge of the lumbar support main body 41 curved in an arc shape and the both side edges intersect, and below the lower edge of the central portion of the lumbar support main body 41. Since it is located, the left and right operation members 43 linked to the both attachment portions 42 are also closer to the lower side of the lumbar support main body 41 that can easily reach the seated person, and the operability of the operation member 43 is improved.

  The left and right attachment portions 42 and the operation member 43 linked to the lower portion of the lumbar support main body 41 can be moved obliquely forward and upward by a portion of the left and right side frame rods 19 facing diagonally forward and below the curved portion C. Further, the upper left and right attachment portions 42 can be moved rearward and upward by a guide member 58 attached to a portion of the left and right side frame ridges 19 facing slightly upward and rearward of the curved portion C. Since it is supported, the movement locus of the lower part and the upper part of the lumbar support main body 41 can be made different. That is, when the lumbar support main body 41 is moved upward from the lower limit position, the lower portion of the lumbar support main body 41 becomes a trajectory moving from the lower side to the diagonally forward upper side, and the upper part is also directed from the lower side to the diagonally rearward upper side. It becomes a moving trajectory.

  As a result, when the vertical position of the lumbar support body 41 is adjusted, it can be moved with a movement trajectory along the curved portion C of the left and right side frame rods 19, so that The rear surface does not strike unevenly, and the waist can be comfortably supported without a sense of incongruity.

  Further, the upper and lower support positions of the lumbar support main body 41 with respect to the side frame rod 19 are at the lower and upper portions of the curved portion C of the side frame rod 19, and the upper, lower, left and right mounting portions 42 of the lumbar support main body 41 are Since the lumbar support 10 moves substantially linearly on different trajectories, the vertical position adjustment of the lumbar support 10 can be performed smoothly without being obstructed by the curved portion C of the side frame rod 19.

  In attaching the lumbar support main body 41 to the back frame 17, the operating member 43 is first attached to the left and right side frame rods 19, and then the connecting hole 49 that opens in the front-rear direction of the connecting member 45 of the operating member 43 is formed in the lower part. The left and right mounting portions 42 of the left and right mounting portions 42 are fitted from the front, and the upper left and right mounting portions 42 are fitted to the concave grooves 24 of the side frame rod 19 from the front, Since it is only necessary to mount the guide member 58 in the groove 24 and prevent the upper mounting portion 42 from being removed, the operation of mounting the lumbar support body 41 to the back frame 17 and the operation with the mounting portion 42 of the lumbar support body 41 are performed. The linking operation with the member 43 can be easily performed from the front of the back frame 17 with the lumbar support main body 41 in the normal posture, and the lumbar support main body 41 can be detached. It is also easy.

  The lower mounting portion 42 of the lumbar support main body 41 and the operation member 43 are separated from each other, and the rear piece 42a of the lower mounting portion 42 of the lumbar support main body 41 is connected to the connection hole 49 of the connection member 45 of the operation member 43. The engagement recess 57 for adjusting the vertical position of the lumbar support main body 41 in stages is fitted to the upward piece 34 as a guide part for guiding the operation member 43 and the upright part. Since it is provided in the inner part spaced apart from the frame 11b, that is, on the front surface of the protruding piece 56 protruding in the concave groove 24 of the side frame rod 19, even if the lumbar support main body 41 is elastically deformed in the front-rear direction, The movement is not directly transmitted to the operation member 43 or the engagement recess 57 via the rear piece 42b.

  Therefore, there is little possibility that a bending load from the lumbar support main body 41 is applied to the entire operation member 43 including the linkage member 45, and the linkage member 45 bends in the thickness direction, and the engagement between the engagement piece 45a and the engagement recess 57 is reduced. The stopping force is not reduced, and the contact portions are not unevenly worn, and the lumbar support main body 41 can be reliably stopped at a fixed position and can be moved up and down stably with a sense of moderation.

  In the above embodiment, in order to prevent the operation member 43 from coming off, the concave groove 48 provided in the inward protrusion piece 44a of the operation member 43 is fitted into the inward protrusion 53 provided in the guide hole 52 of the upward piece 34. However, if the rear piece 42b of the attachment portion 42 linked to the linkage hole 49 of the operation member 43 is fitted so as to be movable only in the front-rear direction, the rear piece 42b of the lumbar support main body 41 is operated by the rear piece 42b. It is possible to prevent the member 43 from coming off.

  Further, in the above-described embodiment, the rearward piece 42 b of the mounting portion 42 of the lumbar support main body 41 is fitted into the linkage hole 49 provided in the operation member 43 and opening in the front-rear direction, so that the mounting portion 42 of the lumbar support main body 41 is fitted. On the contrary, for example, the linking member on the inner side of the operation member 43 is an inward rod (not limited to a circular cross section) and the lumbar support body. If the recessed part opened rearward is provided in the backward piece 42b of the attachment part 42 of 41, and this recessed part is fitted to the inner side part of the rod from the front, the operation member 43 is first moved to the side frame ridge as described above. 19, the rear piece 42 b of the lumbar support main body 41 can be easily fitted and linked to the rod from the front. In this case, a retaining washer for preventing the operating member from moving outward and coming off from the side frame rod 19 is fitted to the tip of the rod inward of the recess. Is good.

  Furthermore, in the above-described embodiment, the upper piece 34 of the cover member 33 and the upright frame 11b of the back support frame 11 to which the cover member 33 is attached are used as guide portions, and the operation member 43 and the lower portion of the lumbar support main body 41 linked thereto are used. The mounting portion 42 is supported and guided so as to be movable in the vertical direction. However, when the cover member 33 and the backrest support frame 11 are omitted, the outer piece of the side frame collar 19 that is thick. 19b may be a guide portion having a guide hole.

DESCRIPTION OF SYMBOLS 1 Caster 2 Leg 3 Leg 4 Pillar 5 Support 6 Seat 7 Axis 8 Back support 9 Back support 10 Lumber support 11 Back support frame 11a Horizontal frame 11b Standing frame (guide part)
12 Back support rod 13 Fitting hole 14 Mounting hole 15 Bolt 16 Female screw hole 17 Back frame 18 Tension material 19 Side frame collar 19a Inner piece 19b Outer piece 20 Upper frame collar 21 Lower frame collar 22 Tension member 23 Tension member 24 concave groove 25 rib 26 fitting recess 27 mounting hole 28 bolt 29 nut holding portion 30 square nut 31 mounting hole 32 bolt 33 cover member 34 upward piece (guide portion)
34a engagement claw 35 inward piece 35a engagement claw 36 engagement piece 36a engagement claw 37 recess 38 downward piece 39 through hole 40 engagement step portion 41 lumbar support main body 42 mounting portion 42a outward piece 42b backward piece 43 operation member 44 Grasping part 44a Inwardly projecting piece 45 Linking member 45a Engaging piece 46 Fitting hole 47 Thick part 48 Recessed groove 49 Linking hole 50 Locking hole 51 Projection 52 Guide hole 53 Inward projecting ridge 54 Thin part 55 Long hole 56 Projection Piece 57 Engaging recess 58 Guide member 58a Inwardly facing piece 58b Backward piece 58c Bottom piece 59 Notch 60 Thick part 61 Engaging groove 62 Engaging protrusion 63 Recess 64 Protruding C Curved part S Gap

Claims (5)

The lower part of the pair of left and right side frame rods in the back frame is curved so as to protrude forward in a side view, and the left and right pair of side frame rods in the vicinity of the curved portion causes both sides of the lumbar support to be In a chair that is movably supported in the direction,
The lumbar support is
A lumbar support body facing left and right,
Four mounting portions provided on both sides of the lumbar support main body and spaced apart in the vertical direction, and the upper left and right mounting portions are guide portions above the curved portions in the pair of left and right side frame rods. The chair is characterized in that it is guided so as to be movable rearward and upward, and the left and right mounting parts are guided so as to be movable forward and obliquely upward by the guide part below the curved part. .   A guide hole in the vertical direction is provided in the guide part below the curved part in the left and right side frame ridges, and the guide member is provided by the guide hole so that the grip portion provided on the guide member protrudes from the outer surface of the side frame ridge. The chair according to claim 1, wherein the chair is supported so as to be movable in the vertical direction, and an inner portion protruding inward from the guide portion of the operation member is linked to the left and right mounting portions.   The chair according to claim 2, wherein the lower mounting portion includes a rear piece, and the rear piece is linked to the inner end of the operation member facing in the left-right direction so as to be detachable from the front.   The left and right widths of the lumbar support main body are made substantially equal to the dimensions between the opposing surfaces of the left and right side frame ridges, and the four mounting portions protrude outward from both side edges of the lumbar support main body, The chair according to any one of claims 1 to 3, which is supported by a guide portion.   A guide member is provided in the front surface above the curved portion of the side frame so as to provide a vertical groove that opens forward, and a guide member that supports and guides the upper mounting portion so as to be movable in the vertical direction. The chair according to any one of claims 1 to 4, which is mounted so as to be detachable from the front.

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