JP2012071026A - Chair with backrest - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce time and labor to attach an auxiliary member in a backrest where the auxiliary member is mounted on a lumbar reception member for supporting a lumbar support device 25 so as to be adjustable in height.SOLUTION: The auxiliary member 27 is mounted on the front surface of the lumbar reception member 16a. The lumbar support device 25 includes an elevation body 19, and the lumbar reception member 16a and the auxiliary member 27 are surrounded by the holding part 19a of the elevation body 19. A lumbar pad 11 is attached to the elevation body 19, and locking is released when a lever 22 is moved downward. Flanges 33 and 35 are formed at both upper and lower ends of the auxiliary member 27 and fitted to the holding grooves 34 and 36 of the lumbar reception member 16a. The lower holding groove 36 is opened diagonally upward. The lower flange 35 is held by right and left holding pieces 35a so as not to be horizontally moved. The upper end of the auxiliary member 27 is held by a holder 28 so as not to be moved forward.

Description

  The present invention relates to a chair having a backrest having a lumbar support function.

  In chairs, the importance of supporting the occupant's lower back (particularly the part centered on the third lumbar vertebra) from behind has been recognized, and there is a lumbar curved in a convex shape in the side view at the bottom of the backrest. Providing a support is common. In this case, the height of the lumbar support varies depending on the user's physique and preference. Therefore, the backrest sheet, which is subject to the body pressure of the seated person, is made of an elastically deformable material, and the height of the backrest sheet is The height of the lumbar support can be adjusted by supporting it from behind with an adjustable lumbar pad (lumbar support).

  As an example, in Japanese Patent Application Laid-Open No. 2004-228867, the applicant of the present invention supports the left and right sides of the back support sheet with lumbar pads in the backrest having a structure in which a mesh-like back support sheet is stretched on the back frame that is open at the front and back. It is disclosed that the lumbar pads are attached to support members each made of a plate material so as to be adjustable in height. According to Patent Document 1, since the lumbar support part of the backrest sheet is in a state of being supported at both ends, the lumbar support part is allowed to deform following the body of the seated person, and as a result, the lumbar support function is improved. Although it is a chair having a high fit to the body and softness to the body (waist) can be obtained.

  On the other hand, in Patent Document 2, the lumbar support support portion is a composite structure of a lumbar support mounting member and a guide member fixed to the front surface of the lumbar support mounting member with a screw. The lumbar support has a structure in which a pad material is attached to the base member. The base member is provided with a horizontal rib that overlaps the front surface of the guide member and a pair of upper and lower guide shafts that overlap the rear surface of the guide member. To hold the lumbar support so that it cannot fall off, and to keep the height of the lumbar support stepwise by fitting the engaging protrusions that project backward on the horizontal rib into the locking grooves of the guide member. Is disclosed.

JP 2010-099104 A JP 2006-280416 A

  In the lumbar support height adjustment mechanism, it is required that the height adjustment operation can be performed with a light force, that the lumbar support can be securely held at a desired height, and that the engaging portion can be processed with high accuracy. Is done. In this respect, Patent Document 2 is configured such that the lumbar support support portion is separated into a lumbar support mounting member and a guide member, and the engagement protrusions and the locking grooves are easily fitted and detached using the bending deformation of the guide member. It can be said that the function required for the lumbar support height adjustment mechanism can be improved.

  However, in the configuration in which the rail portion is screwed to the main body portion as in Patent Document 2, there is a problem in that the assembling workability is poor. In addition, there is a problem that it takes time and effort to form a female screw into which the screw is screwed into the main body, and on the other hand, if the female screw is formed in advance using the main body as a resin molded product, the structure of the mold is There are complications.

  Further, in the configuration in which the engagement protrusion and the locking groove are fitted and detached using the bending deformation of the guide member, if the engagement depth between the engagement protrusion and the locking groove is shallow, the body of the seated person on the lumbar support If a downward external force is applied by the pressure, the lumbar support may slide down, and if the engagement depth between the engagement protrusion and the locking groove is increased, a large force will be required for the lifting operation, and the lumbar support will slide down. There is also a problem that the prevention function and the easiness of the lifting operation conflict. Furthermore, since the guide member continues to receive the bending action, the durability may be lowered.

  This invention makes it a subject to improve such a present condition.

  A chair according to the present invention includes a backrest seat that supports the body pressure of a seated person from behind, a lumbar support device disposed behind the backrest seat, and a lumbar that supports the lumbar support device so that the height thereof can be adjusted. A support member, and an auxiliary member in which an engaging means for holding the height of the lumbar support device is formed on the front surface of the lumbar support member. Is disposed so as to overlap the front surface of the lumbar receiving member, and at least a part of the auxiliary member and the lumbar receiving member are held in a forward-displaceable manner by fitting between the convex portion and the concave portion formed on the auxiliary member and the lumbar receiving member. ing. Note that it is sufficient that the auxiliary member overlaps at least the front surface of the lumbar receiving member, and it does not exclude that the auxiliary member overlaps the side surface of the lumbar receiving portion.

  According to a second aspect of the present invention, in the first aspect, the lumbar receiving member is made of a vertically long plate member and has a narrow front end surface, while the auxiliary member overlaps the front end surface of the lumbar receiving member. A plurality of engaging grooves as the engaging means are formed on the portion of the auxiliary member overlapping the front end surface of the lumbar receiving member so as to jump up and down. The engaging projections that fit into and disengage from the engaging grooves are provided so as to be able to escape from the engaging grooves by the operating means.

  The invention of claim 3 embodies the invention of claim 1 or 2. In this invention, the lumbar support device includes a holding portion that surrounds the auxiliary member and the lumbar receiving member from at least the left and right sides and the near side. have.

  The invention of claim 4 embodies claim 2 or 3, and in this invention, the auxiliary member is in the form of a strip that overlaps the front end surface of the lumbar receiving member, and the upper jaw is at the upper end thereof. While the lower jaw protrudes backward and the lower jaw protrudes backward at the lower end, the lumbar receiving member has an upper holding groove into which the upper jaw fits and a lower holding groove into which the lower jaw fits open forward. One of the upper and lower holding grooves is opened obliquely in a side view or formed in the shape of a dovetail so that one of the jaws fitted in the one holding groove cannot be removed forward. A holding piece for holding the auxiliary member from both the left and right sides is integrally provided on the one jaw, and the other jaw is a body fitted to the auxiliary member and cannot be moved forward and left and right. It is held immovable.

  In the present invention, since the engaging portion is formed on the auxiliary member separate from the lumbar receiving member, for example, by forming the auxiliary member as a resin molded product, the engaging portion can be processed with high dimensional accuracy, It is also possible to change the raising / lowering mode by exchanging auxiliary members, and the lumbar support device can be smoothly slid up and down. That is, the function of the height adjustment mechanism of the lumbar support device can be improved.

  And in this invention, although the auxiliary member is piled up on the front surface of the lumbar receiving member, it can be bent and deformed by partially overlapping the auxiliary member, and the engagement portion can be engaged and disengaged using the bending deformation. It is also possible to ensure, or it is also possible to attach the whole auxiliary member or substantially the whole to the lumbar receiving portion so as not to be bent and deformed. And when it attaches in the state which does not bend and deform | transform, since it can prevent or suppress that a big bending stress arises in an auxiliary member by raising / lowering of a lumbar support apparatus, high durability can be ensured.

  Further, since the auxiliary member is held on the lumbar receiving member so that it cannot be displaced forward by fitting the convex portion and the concave portion, the auxiliary member can be attached without using a screw, thereby improving the efficiency of the assembly work. In addition, since a screw is not required, it is not necessary to provide a female screw on the lumbar receiving member. For this reason, it is possible to reduce the labor of processing the lumbar receiving member, and even if the lumbar receiving member has a shape that makes it difficult to process the female screw. Can be used without hindrance (thus, design freedom is high).

  In the invention of claim 2, since the lumbar receiving member is made of a plate material, it is suitable when the lumbar support device is arranged on the left and right side portions of the backrest as in Patent Document 1. Further, in Patent Document 2, the engaging protrusion and the locking groove are engaged and disengaged by utilizing the flexural deformation of the rail member. However, in this configuration, the engaging protrusion can be moved up and down with a light force. If the engagement between the engagement groove and the locking groove is made shallow, the body pressure may drop, and if the engagement protrusion and the engagement groove are deepened, there is a problem that the lifting operation is difficult. As described above, the engagement protrusion can be moved away from the engagement groove by the operating means, so that the engagement protrusion and the engagement groove are deepened to prevent the lumbar support device from being displaced, The lumbar support device can be adjusted with a light force. In this case, the lumbar support device can be smoothly moved up and down by making the auxiliary member made of a resin made of a material having a small friction coefficient.

  If the structure of Claim 3 is employ | adopted, since an auxiliary member is hold | maintained by the holding part of a lumbar support apparatus so that a right-and-left displacement cannot be performed, the positioning function of an auxiliary member can be improved and it is suitable. In particular, when the lumbar receiving member is made of a plate material as in claim 2 and a belt-like auxiliary member is stacked on the front end surface thereof, the support stability is lowered when the auxiliary member is displaced in the left-right direction. When the configuration is adopted, the auxiliary member is held so as not to be laterally displaced by the holding portion even if it is simply overlapped with the front surface of the lumbar receiving member, so that high stability can be secured. Therefore, the invention of claim 3 is particularly suitable when applied to the invention of claim 2.

  According to the invention of claim 4, the auxiliary member is set on the lumbar receiving member by one-touch operation of fitting one jaw portion into one holding groove and then fitting the lower jaw portion into the other holding groove. Is done. The other jaw is held by a holder (which may be called a cap) so that it cannot be displaced from front to back and from side to side. Therefore, even a thin auxiliary member can be attached with a simple structure in a one-touch manner.

(A) is the whole perspective view of the chair to which this invention is applied, (B) is a side view. (A) is a separated perspective view, (B) is a separated side view. It is a set of the principal part of 1st Embodiment, (A) is a side view, (B) (C) is the perspective view seen from back. It is the perspective view which isolate | separated the whole components. It is a separation perspective view in the state where the lumbar pad was turned sideways. (A) is the isolation | separation perspective view seen from the front, (B) is the isolation | separation perspective view seen from the back. (A) is the perspective view which looked at the principal part from the back, (B) is the separation perspective view which looked at the principal part from the back, (C) is the partial side view which shows the lock mechanism, (D) is the lock mechanism FIG. (A) is a figure which shows a lumbar receiving member and its attachment member, (A) is an isolation | separation perspective view, (B) is an isolation | separation side view of an upper part, (C) is a side view of a lower part. (A) is a whole sectional side view of a locked state, (B) is a partial side view in a locked state. (A) is a sectional side view in the unlocked state, (B) is a partial side view in the unlocked state. It is a figure which shows 2nd Embodiment, (A) is an isolation | separation perspective view, (B) is the perspective view seen from the inner side, (C) is the perspective view seen from the outer side. It is a figure which shows 2nd Embodiment, (A) is a isolation | separation side view, (B) is an isolation | separation perspective view.

  Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to a rocking swivel chair that is frequently used for office work. In the following description and claims, the terms “front and rear” and “left and right” are used to specify the direction, but these front and rear and left and right directions are based on a normal seated person.

(1). Outline of chair First, the outline of the chair will be described with reference to FIGS. The chair includes, as main elements, a leg device 1 having a leg column 2 (gas cylinder), a base 3 fixed to the upper end of the leg column 2, a seat 4 disposed above the base 3, and a backrest 5 on which a seated person rests. It has.

  A pair of left and right swing frames 6 are disposed on the left and right sides of the base 3. The rear portion of the swing frame 6 is a back column 6a that rises upward. The swing frame 6 is connected to the base 3 by a left and right longitudinal support shaft portion 7 so as to tilt backward (turn) around the front end portion thereof. The support portion 7 incorporates a torsion bar as an example of a rocking spring. The left and right swing frames 6 are connected by a lower joint 8 at the lower end of the back column 6a.

  The backrest 5 has a configuration in which a net-like back support sheet 10 is stretched on a back frame 9 having a substantially square shape when viewed from the front, and the back frame 9 is fixed to the back column 6a with screws. The back frame 9 is gently curved in a side view so that a portion corresponding to the waist of the seated person is supported. Therefore, the back support sheet 10 has a lumbar support portion 10a protruding forward in a side view. Lumber pads (pad-like lumbar supports) 11 are in contact with the left and right sides of the lumbar support portion 10a of the back support sheet 10 from behind, and the lumbar support portions 10a of the back support seat 10 are moved up and down by moving the lumbar pad 11 up and down. You can adjust the height. This point will be described later.

  The back frame 9 is a molded product such as a resin, and includes a left and right side member 9a extending in the vertical direction, an upper member 9b connected to the upper ends of the left and right side members 9a, and a lower member 9c connected to the lower ends of the left and right side members 9a. Consists of. Therefore, the back frame 9 has a substantially rectangular shape when viewed from the front. The upper member 9b and the lower member 9c are gently curved in a concave shape facing forward in plan view. For this reason, the lumbar support portion 10a is also recessed in a forward concave shape in plan view.

  The seat 4 is attached to the intermediate member 12 so as to be able to move back and forth. A front portion of the intermediate member 12 is connected to the base 3 via a front link 13. The front link 13 and the intermediate member 12 are connected by a front pin 14.

  A rear link 15 made of a metal plate is disposed on the inner side surface of the swing frame 10. The rear link 15 has a substantially L shape in a side view similar to the swing frame 6, the upright portion 16 extends along the inner surface of the side member 9 a of the back frame 9, and the rear link 15 is in the upright portion 16. It is connected to the swing frame 6 by a pivot pin 17 at a position slightly in front of the base of the. The front end of the rear link 15 protrudes upward, and is connected to the rear end portion of the intermediate member 12 by a rear pin 18. The back column 6a of the swing frame 6 has a substantially L shape in plan view, and the side member 9a of the back frame 9 overlaps the inner surface thereof. The standing part 16 of the rear link 15 is disposed on the left and right inner sides of the side member 6a. The rear anchor 25 has a narrow shape in front view.

  When the seated person leans against the backrest 5, the standing portion 16 of the rear link 15 also tilts backward, but the standing portion 16 also tilts backward relative to the back column 6a. That is, the rate at which the standing portion 16 of the rear link 15 tilts backward is larger than the rate at which the back column 6a tilts backward. And the above-mentioned lumbar pad 11 is attached to the upper end part of the standing part 16 in the rear link 15 so that height adjustment is possible. Therefore, when locking, the lumbar pad 11 moves backward relative to the back column 6a. For this reason, when the back support sheet 10 is locked, the tension is loosened.

(2). Outline of First Embodiment Next, the first embodiment will be described with reference to FIGS. For example, as shown in FIG. 4, the present embodiment includes the above-described lumbar pad 11, a lifting body 19 that is movably mounted on the standing portion 16 of the rear link 15, and the lumbar pad 11 and the lifting body 19. The movable lock body 20 and the auxiliary metal fitting 21 that are arranged, and a lever 22 as an example of an operation means are provided, and these are unitized to constitute a lumbar support device 25. The lumbar pad 11, the elevating body 19, and the movable lock body 20 are made of resin, and the auxiliary metal fitting 21 is made of metal. The lumbar support device 25 can also be referred to as a lifting unit. Needless to say, the lumbar support device may include at least the lumbar pad 11.

  The lever 22 has a horizontally elongated central axis (rotating axis) 23, and a flap 22 a extends behind the central axis 23. More precisely, the lever 22 is formed by fixing a resin flap 22a with a screw (not shown) to an L-shaped bar member in plan view with the front portion as the central axis 23, and a seated person Can turn the arm back and put the fingertips on the flaps 22a (may be operated by getting off the chair).

  The upper portion of the standing portion 16 of the rear link 15 is formed with a narrow lumbar receiving member 16a, while the lifting body 19 has a trapezoidal holding portion that is fitted in the lumbar receiving member 16a from above. 19a is formed, and therefore the elevating body 19 is mounted on the lumbar receiving member 16a so as to be only movable up and down. The elevating body 19 is opened forward, the auxiliary metal fitting 21 is disposed therein, and the movable lock body 20 is fitted into the auxiliary metal fitting 21. More precisely, the auxiliary metal fitting 21 has a U-shape, in which the movable lock body 20 is fitted, and the auxiliary metal fitting 21 is housed inside the elevating body 19.

  As can be understood from FIG. 5, inner and outer side ribs 24 a and 24 b are integrally formed on the back surface of the lumbar pad 11. As can be understood from FIGS. 4 and 5, the central shaft 23 of the lever 22 penetrates the inner and outer side ribs of the lumbar pad 11, the elevating body 19, the auxiliary metal fitting 21, and the movable lock body 20. Therefore, the lumbar support device 25 having the lumbar pad 11, the movable lock body 20, the auxiliary metal fitting 21 and the lifting body 19 moves up and down integrally.

  A resin-made auxiliary member 27 is mounted on the front surface of the lumbar receiving member 16a so as not to move up and down (the auxiliary member 27 can also be called an edge member or a slider). The upper part of the auxiliary member 27 is held by the lumbar receiving member 16a so as not to be displaced by a pair of left and right holders 28a and 28b.

  The auxiliary member 27 is formed with a plurality of engaging grooves 29 as an example of a fixed engaging portion constituting a locking means (engaging portion), while the movable lock body 20 has a movable engagement member. As an example of the joint portion, an engagement protrusion 30 that fits into the engagement groove 29 is formed. When the engagement protrusion 30 and the engagement groove 29 are engaged, body pressure is applied to the lumbar pad 11. When locked in a state that does not slide down and the lever 22 is turned downward, the lock (regulation) is released and the lumbar pad 11 can be moved downward.

  When the seated person's body pressure is applied to the lumbar support device 25, the body pressure may include a downward or upward component force. For this reason, the lumbar support device 25 is lowered or lifted by the seated person's body pressure. May have a tendency to shift.

  In the chair of the present embodiment, the lumbar pad 11 tends to shift downward due to body pressure, but does not tend to shift upward. Therefore, only the downward movement of the lumbar pad 11 is locked, and the upward movement is performed by using elastic deformation of a member of the movable lock body 20 (details will be described later). For example, as shown in FIGS. 4 and 5, a U-shaped cover 31 in a plan view is disposed behind the lumbar receiving member 16a. The cover 31 is attached to the side member 6 a of the back frame 6. Next, details of each member will be described.

(3) Lumber receiving member and its associated elements First, the lumbar receiving member 16a of the rear link 15 and its associated elements will be described mainly with reference to FIG. As shown in FIG. 6, an upper jaw 33 is formed at the upper end of the auxiliary member 27, and an upper holding groove 34 into which the upper jaw 33 is fitted is formed in the lumbar receiving member 16a. A lower jaw part 35 protruding rearward is formed at the lower end of 27, and the lower jaw part 35 is fitted in a lower holding groove 36 of a forward opening formed in the standing part 16 of the rear link 15. The lower holding groove 36 is opened obliquely upward, so that the lower jaw 35 is held so as not to move forward.

  In addition, the lower jaw portion 35 is integrally formed with a sandwiching piece 35 a that sandwiches the upright portion 16 from the left and right sides. For this reason, the lower jaw portion 35 is thicker than the plate thickness of the rear link 15. The lower part of the auxiliary member 27 is held so as not to be laterally shifted by the sandwiching piece 35a. For example, as can be understood from FIGS. 8A and 8B, the clamping piece 35 a of the lower jaw portion 35 can also function as a stopper that regulates the lower limit position of the elevating body 19.

  As described above, the upper jaw portion 33 of the auxiliary member 27 is held by the holders 28a and 28b so as not to be displaced. Both holders 28a, 28b are formed with meshing ribs 38, 39. By fitting the ribs 38, 39 against elasticity, a state in which the lumbar receiving member 16a is sandwiched is maintained. In addition, the rib 39 of the outer holder 28b is formed with a pressing portion 39a that fits into the upper holding groove 34 of the lumbar receiving member 16a, thereby holding the auxiliary member 27 without any play.

  The upper end surface 33a of the auxiliary member 27 has an inclined surface that becomes higher as going backward, while the lower surface 39a 'of the pressing portion 39a in the outer holder 28b is inclined so as to overlap the upper end surface 33a of the auxiliary member 27. For this reason, the upper end portion of the auxiliary member 27 is held so as not to move forward. In the present embodiment, the holders 28a and 28b are constituted by two members. However, the holders 28a and 28b may be fitted into the lumbar receiving member 16a as a single structure opened downward (in this case, however, the holder is the lifting body 19). It cannot have the function of a vertical height restriction stopper.)

  An upper rear groove 34a opened rearward is formed in the lumbar receiving member 16a, and a rear rib 39a formed in the outer holder 28b is fitted into the rear groove 34a. The upper limit height of the elevating unit 25 is regulated by the holding portion 19a of the elevating body 19 coming into contact with the holders 28a and 28b. However, since the holders 28a and 28b are fitted to the lumbar receiving member 16a on both the front and rear sides, The stopper function for the body 19 can be exhibited accurately.

  The auxiliary member 27 first inserts the lower jaw 35 into the lower holding groove 36 of the lumbar receiving member 16a, then inserts the upper jaw 33 into the upper holding groove 34, and then sets the outer holder 28b to the lumbar receiving member 16a. Then, the inner holder 28a is attached by the procedure of overlapping the lumbar receiving member 16a and the outer holder 38b. As a result, the auxiliary member 17 is held so as not to be able to shift back and forth and right and left as a whole, and the auxiliary member 27 is held as a whole so that it cannot move up and down.

  The engagement grooves 29 of the auxiliary member 27 are formed in pairs (two rows) on the left and right. Therefore, the left and right intermediate portions of the auxiliary member 27 are flat surfaces where the engagement grooves 29 do not exist. As clearly shown in FIGS. 9B and 10B, the lower surface 29a of the inner circumferential surface of the engagement groove 29 is close to 90 ° with respect to the front surface of the auxiliary member 27 in a side view. While the upper surface 29b is inclined at a large angle, the crossing angle is small so that the upper surface 29b lies largely against the front surface of the auxiliary member 27 in a side view. Accordingly, the engagement protrusion 30 fitted in the engagement groove 29 is difficult to move downward but easy to move upward.

(4). Lumber Support Device Next, the lumbar support device 25 will be described in detail. The lumbar pad 11 has an elongated shape in the vertical direction, and the front surface of the lumbar pad 11 is curved forward and convex with a large curvature in a side view, and is also curved forward and convex in a plan view.

  For example, as shown in FIGS. 4 and 5, the elevating body 19 protrudes from both the upper and lower sides of the holding portion 19a and has a long shape as a whole, and the central shaft 23 of the lever 22 penetrates the left and right side plates 19b. ing. Further, a boss portion 40 is formed at the lower portion of the lifting body 19, and the lumbar pad 11 is fixed to the lifting body 19 with a screw 41 screwed into the boss portion 40.

  Further, as clearly shown in FIG. 9A, an upper inner rib 42 that connects the left and right side plates 19b is formed in an upper portion of the lifting body 19 and an overhanging portion 42a formed on the upper inner rib 42 is formed. In addition, a hook 43 formed on the inner surface of the lumbar pad 11 is hooked from above. For this reason, the lumbar pad 11 is fixed to the elevating body 19 with only one screw 41 so as not to be separated from the front and rear.

  The auxiliary metal fitting 21 has a vertically long and narrow shape, and is fitted tightly between the left and right side plates 19b of the lifting body 19. As shown in FIG. 9, the auxiliary metal fitting 21 is supported by the upper and lower receiving portions 44 provided on the elevating body 19. For this reason, the auxiliary metal fitting 21 is in a state similar to that fixed to the elevating body 19. Yes. The auxiliary metal fitting 21 has a U-shape having left and right side plates and a bottom plate 21a, and the movable lock body 20 is disposed between the left and right side plates.

  The movable lock body 20 has a shape that is long in the vertical direction, and the central shaft 23 of the lever 22 passes through a substantially middle part in the vertical direction. The movable lock body 20 is fixed to the central shaft 23 with screws 45. Therefore, when the lever 22 is rotated, the movable lock body 20 is rotated integrally with the central shaft 23. For example, as shown in FIG. 7, a flat portion 23a is formed on the front surface of the central shaft 23, and a washer 46 is overlaid on the flat portion 23a. In FIG. 7, the washer 46 is depicted in a state of being disposed outside the movable lock body 20, but as shown in FIGS. 9 and 10, the washer 46 overlaps the flat portion 23 a of the central shaft 23. For this reason, the movable lock body 20 is firmly fixed to the central shaft 23. The washer 46 is fitted into the through hole 20a (see FIG. 7) provided in the movable lock body 20 from the side. ).

  A downwardly extending arm 47 is integrally formed on the rear surface of the movable lock body 20, and an engagement protrusion 30 is formed at the tip (lower end) of the arm 47. As shown in FIGS. 7, 9, and 10, a window hole 48 for exposing the arm 47 of the movable lock body 20 toward the auxiliary member 27 is formed in the bottom plate 21 a of the auxiliary metal fitting 21. As described above, the engagement grooves 29 of the auxiliary member 27 are formed in pairs on the left and right. Therefore, as shown in FIG. 8D, the engaging protrusion 30 of the movable lock body 20 is bifurcated. For this reason, there is an advantage that the operation is ensured by preventing the blur in the left-right direction. Further, the shape of the engagement protrusion 30 in a side view is a rounded trapezoid (if the trapezoidal shape is formed, the contact area between the engagement protrusion 30 and the engagement groove 29 can be increased, thereby suppressing wear. And improve durability.)

  For example, as shown in FIGS. 9A and 10A, a spring 49 as an example of an elastic body is interposed between the upper end portion of the movable lock body 20 and the bottom plate 21 a of the auxiliary metal fitting 21. Therefore, the movable lock body 20 is urged so that the engagement protrusion 30 is fitted in the engagement groove 29 of the auxiliary member 27 and becomes free. The elastic force of the spring 49 is set to be stronger than the elastic force of the arm 47.

(5) Summary of First Embodiment In the above configuration, as shown in FIG. 9, when the engaging protrusion 30 is fitted in any of the engaging grooves 29, the engaging protrusion 30 is engaged with the engaging groove 29. Therefore, even if a downward external force is applied to the lumbar pad 11 by the body pressure of the seated person, the lumbar pad 11 does not slide down. For this reason, the lumbar pad 11 is held at a desired height. In addition, since the lumbar pad 11 is pushed backward by the tension of the back support sheet 10, the engagement state between the engagement protrusion 30 and the engagement groove 29 is maintained.

  In order to reduce the height of the lumbar pad 11, a downward force is applied by grasping the flap 22a of the lever 22 with a finger. Then, the central shaft 23 of the lever 22 rotates. As shown in FIG. 10, the movable lock body 20 rotates together with the central shaft 23 so that the engagement protrusion 30 is separated from the movable lock body 20. For this reason, if the flap 22a of the lever 22 is continuously pushed, the lumbar support device 25 can be lowered.

  That is, when the flap 22a of the lever 22 is pressed downward, first, the engagement depth of the engagement protrusion 30 with respect to the engagement groove 29 is reduced, so that the lock is released, and then the lumbar support device 25 is lowered. Therefore, the unlocking and the downward movement of the lumbar support device 25 are performed in a series by one action of pushing the flap 22a downward. For this reason, it is excellent in operability.

  When the movable lock body 20 rotates in the unlocking direction, the unlocking posture is regulated by the upper end portion of the movable lock body 20 coming into contact with the bottom plate 21a of the auxiliary metal fitting 21. In this state, the engagement protrusion 30 is not completely separated from the engagement groove 29 but is slightly in the engagement groove 29.

  Therefore, when the lumbar support device 25 is lowered, when the engagement protrusion 30 is disengaged from the engagement groove 29, the arm 47 of the movable lock body 20 is slightly bent and deformed. As a result, a person can get a clicking feeling, and when the engaging protrusion 30 reaches the lower engaging groove 29, the arm 47 is returned and deformed by the elastic restoring force, and the resistance to the downward movement is weak. At the same time, people can get a sense of clicking.

  By obtaining a click feeling in this manner, the chair user can accurately grasp the state in which the height changes stepwise and stop the chair at a desired height. In particular, when the lumbar support devices 25 are provided separately on the left and right as in the embodiment, the left and right lumbar support devices 25 are set to the same height in order to obtain the same click feeling in the left and right lumbar support devices 25. Can be set accurately. In addition, the problem that the engagement protrusion 30 is positioned between the engagement groove 29 and the engagement groove 29 can be remarkably suppressed.

  In Patent Document 2, a click feeling is obtained by elastic deformation of the guide member. In this case, due to an assembly error or the like, the engagement / disengagement hardness between the engagement protrusion and the locking groove varies, and the click feeling also occurs. In this embodiment, the auxiliary member 27 does not deform, but obtains a click feeling by using the elastic deformation of the arm 47, and the processing accuracy and assembly accuracy of the arm 47 are also high. And a uniform click feeling can be obtained.

  When raising the lumbar support device 25, an upward external force may be applied to the flap 22a of the lever 22. In this case, the lever 22 and the movable lock body 20 do not rotate, and as shown in FIG. 10B, the upward movement of the lumbar support device 25 is allowed as the arm 47 of the movable lock body 20 is bent and deformed. . Needless to say, the lever 22 may be configured to be unlocked by rotating only in the upward direction, or may be configured to be unlocked by rotating in any direction.

  When the upward movement of the lumbar support device 25 is allowed only by the deformation of the arm 47, the fitting depth between the engagement protrusion 30 and the engagement groove 29 is made as small as possible, and the bending deformation of the arm 47 is made as small as possible. Is preferred. However, when the engagement depth between the engagement protrusion 30 and the engagement groove 29 becomes shallow, there is a possibility that a phenomenon of sliding down due to the body pressure of the seated person may occur.

  On the other hand, in this embodiment, the lower surface 29a of the engagement groove 29 intersects with the front surface of the auxiliary member 27 at a large angle, and the upper surface 29b of the engagement groove 29 has a small angle with respect to the front surface of the auxiliary member 27. Since they are crossed, the engagement protrusion 30 and the engagement groove 29 can be prevented from slipping down while making the fitting depth between the engagement protrusion 30 and the engagement groove 29 as shallow as possible. Therefore, it is possible to perform the ascending operation with a light force while accurately maintaining the locking function against the sliding down.

  As indicated by a dotted line in FIG. 10, an elastic body 50 such as rubber or a spring can be interposed between the main body portion of the movable lock body 20 and the arm 47. This configuration has an advantage that the engagement state between the engagement protrusion 30 and the engagement groove 29 can be continuously secured even if the arm 47 has a sag phenomenon. In the present embodiment, the engagement protrusion 30 has a trapezoidal shape in a side view, and the front surface and the lower surface thereof are in close contact with the engagement groove 29. For this reason, the engagement protrusion 30 and the engagement groove 29 are in surface contact over a long range, and thus wear is suppressed and the durability is excellent.

  Further, the movable lock body 20 can be directly attached to the lifting body 19 without using the auxiliary metal fitting 21, but in this case, a mold for molding the lifting body 19 becomes very complicated, The problem of wear due to rotation of the central shaft 23 may also occur. On the other hand, when the auxiliary metal fitting 21 is used as in the present embodiment, the elevating body 19 can be manufactured using a mold that can be easily punched, and the auxiliary metal fitting 21 functions as a bearing member. There is also an advantage that can be secured. It is also possible to configure the movable lock body with a plurality of parts separated front and rear.

(6). Second Embodiment In the second embodiment shown in FIGS. 11 and 12, the lever 22 and the slide body 19 are integrally formed, and the lumbar pad 1, the movable lock body 53, and the lower end portion of the slide body 19 are provided. Are connected by a longitudinally extending pin 54. In this embodiment, the lumbar pad 11 has a pair of left and right bearing ribs 55 that enter the inside of the elevating body 19. A movable lock body 53 is disposed between the left and right bearings 55, and the bearing rib 55 and the movable lock body are located. A pin 54 passes through 53.

  The movable lock body 53 extends long above the pin 54, and the engagement protrusion 30 is formed at a portion near the upper end. Further, a rubber 56 as an example of an elastic body is disposed in front of the movable lock body 53, and the rubber 56 is supported by a front plate 57 of the elevating body 19. A window hole 58 for fitting the rubber 56 is formed in the elevating body 19. Since the window hole 58 is blocked by the left and right ribs 59 of the lumbar pad 11, the rubber 56 does not come off.

  The auxiliary member 27 has a front plate that overlaps the front surface of the lumbar receiving member 16a, a side plate that overlaps one side surface of the lumbar receiving member 16a, and a rear plate that overlaps the rear surface of the lumbar receiving member 16a. Accordingly, the auxiliary member 27 has a U-shape in plan view, the boss 60 is provided on the side plate, and the lumbar receiving member 16a has a hole 61 in which the boss 60 is fitted. The boss 60 is preferably forcibly fitted into the hole 61.

  In this embodiment, the auxiliary member 27 is held by the boss 60 and the hole 61 so that it cannot be displaced vertically and forward and backward. The holder 28 and the lumbar receiving member 16a have a hole penetrating them, and the holder 28 is held so as not to move upward by passing a pin through the hole. Therefore, a stopper function that restricts the upper limit of the lifting body 19 Is demonstrating.

  This second embodiment does not have a lock release function, and the height of the lumbar support device 25 is adjusted by rotating the movable lock body 53 against the elasticity of the rubber 56. Also in this embodiment, since the auxiliary member 27 is surrounded from the periphery by the holding portion 19 a of the elevating body 19, the auxiliary member 27 is held so as not to be displaced only by fitting the boss 60 and the hole 61.

  Although not shown in the drawing, the auxiliary member 27 can be formed in a square tube that completely covers the lumbar receiving member 16a (the downward movement is restricted by the step 32, and the upward movement is restricted by the holder 28). .) In this case, the auxiliary member 27 is held by the holding unit 19a of the lifting body. Further, the auxiliary member 27 has a front plate that overlaps the front surface of the lumbar receiving member 16a and left and right side plates that overlap the left and right side surfaces of the main lumbar receiving member 16a (that is, a U-shape that opens backward in plan view). It is also possible to do.

(7). Others The present invention can be embodied in various ways other than the above embodiment. For example, the lumbar support device does not necessarily have to be attached to the standing portion of the rear link, and the lumbar support member may be set according to the structure of the chair, such as being attached to the back frame or the back column. In the embodiment, the lumbar pads are arranged independently on the left and right. However, the lumbar pads can have a single structure, and therefore, any shape can be selected, such as forming in a horizontally long form. When the lumbar pad is separated into left and right, the left and right levers can be connected by a horizontally long joint, and the left and right lumbar pads can be lifted and lowered simultaneously via the joint.

  When the lock means and the operation means are provided, various configurations can be adopted. For example, a push button can be adopted as the operation means, and the movement of the push button can be converted into the movement of the movable lock body by a cam mechanism or a link mechanism. It is also possible to configure the lever to be vertically slidable so that the lock is released in its downward movement or upward movement, or both. In this case, the lock can be released and the height can be adjusted with one action. It is also possible to form the engaging groove on the device side and the engaging protrusion on the lumbar receiving member.

  As the lock mechanism, instead of fitting the engagement protrusion and the engagement groove, for example, fitting of serrated irregularities or fitting of a pin and a hole can be employed. It is also possible to configure the movable lock body with a plurality of members (or arrange another interlocking member between the movable lock body and the lever). It is also possible to use a deformable resin plate as the back support sheet, and it is also possible to stretch a cushion on the front surface of the back support sheet.

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

DESCRIPTION OF SYMBOLS 5 Backrest 10 Back support sheet 10a Lumber support part 11 Lumber pad 15 Rear link 16a Lumber support member 19 Lifting body 20 Movable lock body 21 Auxiliary metal fittings 22 Lever 23 Center axis of lever 25 Lumber support device 27 Auxiliary member 29 Engaging groove 30 Engagement Joints 33 Upper jaw 34 Upper retaining groove 35 Lower jaw 36 Lower retaining groove

Claims (4)

A backrest seat that supports the body pressure of a seated person from behind, a lumbar support device disposed behind the backrest seat, and a lumbar support member that supports the lumbar support device so that the height of the lumbar support device can be adjusted. And an auxiliary member in which an engaging means for holding the height of the lumbar support device is formed on the front surface of the lumbar receiving member.
The auxiliary member is disposed so as to overlap the front surface of the lumbar receiving member, and at least a part of the auxiliary member cannot be displaced forward by fitting between a convex portion and a concave portion formed on the auxiliary member and the lumbar receiving member. Held in the
Chair with backrest. The lumbar receiving member is made of a vertically long plate and has a narrow front end surface, while the auxiliary member has a portion overlapping the front end surface of the lumbar receiving member. A plurality of engagement grooves as the engagement means are formed in a portion that overlaps with the front end surface of the lumbar receiving member so as to jump up and down, and the lumbar support device has an engagement protrusion that fits into and out of the engagement groove. Is provided so that it can be moved away from the engagement groove by the operating means.
A chair with a backrest according to claim 1. The lumbar support device has a holding portion that surrounds the auxiliary member and the lumbar receiving member from at least the left and right sides and the near side,
A chair with a backrest according to claim 1 or 2. The auxiliary member is in the form of a strip that overlaps the front end surface of the lumbar receiving member, with the upper jaw projecting rearward at the upper end and the lower jaw projecting rearward at the lower end. In the member, an upper holding groove into which the upper jaw part fits and a lower holding groove into which the lower jaw part fits open forward,
Either one of the upper and lower holding grooves is opened obliquely in a side view or formed in the shape of a dovetail, thereby holding one jaw part fitted in the one holding groove so as not to be able to come forward, In addition, a clamping piece for sandwiching the auxiliary member from both the left and right sides is integrally provided on the one jaw, and the other jaw is made immovable forward and left and right by a holder fitted to the auxiliary member. Retained,
A chair with a backrest according to claim 2 or 3.

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