JP4160850B2 - Chair - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chair provided with a lock device for a backrest.
[0002]
[Prior art]
In a rocking chair provided with a backrest that can be tilted rearwardly, a tilt lock device that can switch the backrest between a free state in which the backrest can be tilted and a locked state in which the rear tilt cannot be performed is provided.
[0003]
In this locking device, there are a stepwise locking device that can lock the backrest in several steps such as two or three steps, and a stepless locking device that can lock the backrest in any posture. It can be said that the locking device is more convenient because it can respond to the user's preference.
[0004]
And as a representative example of a stepless locking device, there are one using a gas cylinder and one using a friction plate group as disclosed in Patent Document 1, for example. The used one is compact and has the advantage that it can be manufactured at low cost.
[0005]
In addition to the friction plate group, the lock device using the friction plate group includes a lock shaft that passes through a long hole formed in the friction plate group, and a bearing that supports the lock shaft on both sides of the friction plate group. A metal fitting, a clamping member that switches between a locked state in which the friction plate group is clamped and a free state in which the clamping pressure is released, and a lever that operates the clamping member are provided. The efficiency of the assembling work of the chair is intended by incorporating the above into a unit.
[0006]
In Patent Document 2, an apparatus for adjusting the tilt range after the backrest using the friction plate group has been proposed (this device is also a type of locking device for the backrest, which is the subject of the present invention.).
[0007]
[Patent Document 1]
JP 20018772 A [Patent Document 2]
Japanese Patent Laid-Open No. 2001-95641
[Problems to be solved by the invention]
By the way, in the friction plate type locking device, the bearing bracket includes left and right side plates that have holes for fitting the lock shafts, and a top plate connected between the upper ends of the left and right side plates. A friction plate group and a pinching member are arranged in a space surrounded by.
[0009]
Conventionally, the bearing hole formed in the side plate of the bearing fitting for receiving the lock shaft is a round hole. Therefore, when assembling the lock device, the friction plate group and the pressing member are arranged in the same space in the space between the left and right side plates of the bearing fitting, and the lock shaft is inserted through them.
[0010]
However, since it is troublesome to arrange a large number of friction plates and other members in a narrow space in a uniform posture, the assembling work of the lock device has been troublesome. In particular, when a thin washer is interposed between the friction plates, it is troublesome to maintain the posture of the washer group, so that the assembling work is further troublesome.
[0011]
In addition, when the lock device is incorporated in the base of the chair, the friction plate group is linked to the backrest by inserting a slide shaft that moves in conjunction with the backrest, for example, into a round hole formed in the friction plate group. However, it is troublesome to hold the friction plates so that the round holes are concentric, and this makes it difficult to attach the friction plates to the chair.
[0012]
An object of the present invention is to improve such a current situation.
[0013]
[Means for Solving the Problems]
Chair according to the invention of claim 1 includes a base mounted on legs, and supported the seat in the base, a backrest which can be post-tilt against the spring means, and after freely free state rear tilting the backrest is provided with a locking device to switch to the tilt non locked state, the locking device includes a friction plate group formed by superimposing a large number of friction plates, through the long hole formed in said friction plate group a lock shaft that a bearing bracket for supporting the locking shaft in both sides of the friction plate group, the sliding pressing members for pressing said friction plate group from one side, the side friction plate group other And a lever for operating the slidable clamping member .
[0014]
Further, by linking one of the friction plate group and the lock shaft to the tilting of the backrest, the backrest is switched between the locked state and the free state by the clamping / release of the friction plate group. The bearing bracket is provided with two bearing holes for supporting the lock shaft on both sides of the friction plate group, and the both bearing holes have a direction perpendicular to the axis of the lock shaft. It is formed in the slit hole which has an opening part so that it can be moved and fitted.
[0015]
The slide-type pressing member is inserted through the lock shaft and is slidably and non-rotatably fitted into one bearing hole, while the fixed-type pressing member is inserted through the lock shaft. At the same time, it is fitted in the other bearing hole in a state where it cannot move to the outside of the bearing fitting, and the sliding clamping member slides by the rotation of the lock shaft, and the friction plate group is clamped and released. Furthermore, both the bearing holes of the bearing fitting have a keyhole shape in which the width of the opening is smaller than the inner diameter, and the sliding-type pressing member has an opening in one of the bearing holes. The fixed clamping member has a flange that abuts against the inner surface of the bearing fitting and supports the friction plate group, and has a fixed clamping pin. The length of the pressure member that can be fitted between both bearing holes Going on.
[0016]
In Claim 2, in Claim 1, the said base is formed in the box shape of the upward opening provided with the right-and-left side board, and it is interlocked with the backrest in the oblong hole formed in the right-and-left side board of the said base. The left and right longitudinal slide shafts are inserted.
[0017]
On the other hand, the lock shaft is disposed inside the base so as to extend in parallel with the slide shaft, and a bush through which the slide shaft passes is inserted into the friction plate group, and further, the bearing bracket or the base the friction plate group posture holding means for holding the bushing in the state close to concentrically or its elongated hole in the base is provided before insertion of the slide shaft.
[0018]
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0020]
(1). Overview of the chair (Figs. 1-3)
First, the outline | summary of a chair is demonstrated based on FIGS. 1-3. 1 is a side view, FIG. 2 is an exploded perspective view of the mechanism, and FIG. 3 is a longitudinal side view. In FIGS. 1 to 3, the locking device is omitted for convenience.
[0021]
The chair includes a leg 1, a seat 2, a backrest 3, and an armrest device 4. The leg 1 includes a leg column (gas cylinder) 5 whose height is adjustable, and a base 6 that is open upward is attached to the upper end of the leg column 5. The base 6 is made of a metal plate, and a long hole 7 is formed in the front portion of the left and right side plates 6a in a slightly tilted posture in a side view.
[0022]
An intermediate member 8 made of a metal plate is disposed above the base 6. The intermediate member 8 includes a side plate 8 a located on the left and right outer sides of the base 6, and a first support shaft (slide shaft) 9 is inserted through the side plate 8 a of the intermediate member 8 and the long hole 6 a of the base 6. In addition, although the synthetic resin bush is fitted in the base 6 and the intermediate member 8, it is abbreviate | omitting in the figure.
[0023]
An auxiliary bracket 10 having a U-shaped opening facing downward is fixed to the lower surface of the front portion of the intermediate member 8, and the first support shaft 9 also penetrates the side plate of the auxiliary bracket 10. For this reason, bending of the 1st spindle 9 can be prevented, and the seat 2 can be supported stably.
[0024]
A lower bracket 11 having a U-shaped opening facing downward is fixed to the lower surface of the base 6 in the vicinity where the pedestal 5 is attached. A swing frame 13 is attached to the lower bracket 11 by a second support shaft 12. It is attached so that it can tilt backward. The backrest 3 has a structure in which a cushion is stretched on an outer shell made of synthetic resin or the like, and the outer shell is fixed to the swing frame 13.
[0025]
The rear part of the intermediate member 8 and the front and rear halfway part of the swing frame 13 are connected by a third shaft 14. For this reason, when the backrest 3 tilts backward, the intermediate member 8 moves backward. The rearward tilt of the swing frame 13 is elastically supported by a spring 16 supported by an adjustment knob 15. The arrangement position of the spring 16 can be freely set.
[0026]
The seat 2 has a structure in which a cushion is stretched on the inner shells 16 and 17 divided in the front-rear direction, and the front inner shell 16 is attached to the intermediate member 8 so as to be able to tilt rearward and not to be separated from the upper part. . On the other hand, the rear inner shell 17 is locked to the swing frame 13. In the chair of the present embodiment, the seat 2 can be moved backward by a certain size after the intermediate member 8 has been tilted backward.
[0027]
Needless to say, the chair to which the present invention can be applied is not limited to the illustrated chair, and can be widely applied to a chair whose backrest tilts backward.
[0028]
(2). Structure of Lock Device Next, the structure of the lock device will be described with reference to FIGS. 4 is a partially broken plan view of the mechanism, FIG. 5 is a plan view of the locking device 19, FIG. 6 is a perspective view of the locking device 19 separated from the base 6, and FIG. 8 and 9 are separated perspective views of the members, FIG. 10 is a side sectional view showing the operation, FIG. 11A is a sectional view taken along the line AA in FIG. 5, and FIG. FIG. 12 is a cross-sectional view taken along the line BB of FIG. 5 and FIG. 12 is a cross-sectional view taken along the line XII-XII of FIG.
[0029]
As can be easily understood from FIG. 7, for example, the locking device 19 includes a friction plate group 23 formed by alternately laminating front and rear oval friction plates 20 and front and rear washers 21 and 22 having a large friction coefficient, and friction plates. A lock shaft 24 penetrating the group 23, a lever (handle) 25 fixed to the outer end of the lock shaft 24, a bearing fitting (bearing member) 26 that supports the lock device 19, and a sliding-type clamping member ( sliding member) (Moving cam body ) 27 and a rotating cam body 28, a fixed pressing member 33, and a plurality of disc spring washers 29.
[0030]
For example, as shown in FIGS. 4 to 6, the side plate 6 a of the base 6 has a window hole 42 through which the lock shaft 24 is inserted. In each plan view, the washers 21 and 22 are omitted.
[0031]
The front portion of the friction plates 20 are vacant first hole 30 of the small determine type, fitted with first bore 30 made of synthetic resin Bush 31 of the friction plate 20, first to Bush 31 of this One spindle 9 is inserted . Bush 31, while a large-diameter portion 31a that overlaps the surface of, and a split-shaped shaft portion 31b which penetrates into the friction plate group 23, the friction plate group at the distal end of the shaft portion 31b of the friction plate group 23 A claw 31 c is formed so as to overlap the other surface of 23.
[0032]
Accordingly, the friction plates 20 and the front washer 21 is separated non retained by Bush 31. Since the shaft portion 31b of the Bush 31 is located around the load acts between the first shaft 9 through the shaft portion 31b of Bush 31 and the friction plate 20. For this reason, damage to the first shaft 9 can be prevented.
[0033]
When the shaft portion 31b of the Bush 31 as in the present embodiment is formed into a plurality split shape to form a claw 31c on the tip, since that by utilizing the elasticity of the shaft portion 31b fitted into the friction plate group 23, structure There is an advantage to be simple. Of course, it is also possible to form the shaft portion 31b in a cylindrical shape and attach a retaining member such as a nut or a snap ring to the tip of the shaft portion 31b.
[0034]
Each friction plate 20 has a longitudinal second hole 32 positioned behind the first hole 30, and a fixed clamping member 33 is fitted into the second hole 32 and the rear washer 22, The lock shaft 24 is inserted through the fixed clamping member 33.
[0035]
The bearing fitting 26 is formed by processing a metal plate into a sheet metal, and the left and right side plates 26 a in which the bearing holes 34 for supporting the lock shaft 24 are formed to open upward, and the left and right side plates 26 a on both the front and rear sides of the bearing holes 34. Front and rear top plates 26b and 26c are integrally connected, and a friction plate group 23 is arranged in a space sandwiched between the left and right side plates 26a.
[0036]
As shown in FIG. 12, the friction plate group 23 is in close contact with the front and rear top plates 26b and 26c of the bearing fitting 26, and the friction plate group 23 is set so as to be retracted to below the rear top plate 26c. Yes. Further, the friction plate group 23 is set so that the center of gravity is located forward of the lock shaft 24 in the fully retracted state. The bearing fitting 26 is fixed to the bottom surface of the base 6 by screws (screws) 35 (for example, see FIG. 6 ) inserted into the base 6 from below.
[0037]
The bearing hole 34 of the bearing fitting 26 has a larger diameter than the lock shaft 24, and the opening 34a has a keyhole shape narrower than the inner diameter . At one end portion (right end portion) of the fixed clamping member 33, a large-diameter flange 33a that overlaps the inner surface of the other side plate 26a of the bearing fitting 26, and a boss portion 33b that fits in the other bearing hole 34 so that it cannot be pulled upward. And form.
[0038]
The sliding-type clamping member 27 is made of synthetic resin, and a boss portion 27a that fits into one bearing hole 34 of the bearing fitting 26 from the outside, and a flange portion 27b that overlaps one side plate 26a of the bearing fitting 26 from the outside. The key portion 27c that fits into the opening 34a of the bearing hole 34 is formed integrally with the boss portion 27b. Therefore, the sliding cam body 27 is held so as not to rotate but to move in the axial direction.
[0039]
The other end portion of the fixed pressing member 33 protrudes slightly from the friction plate group 23 and is fitted into the boss portion 27 a of the sliding pressing member 27. For this reason, even if the sliding pinching member 27 moves slightly in the axial direction, the entire friction plate group 23 is reliably supported by the fixed pressing member 33.
[0040]
As clearly shown in FIG. 8, a pair of driven cam portions 36 sandwiching the shaft center are formed on the outer end surface of the sliding pressure member 27. The driven cam portion 36 includes an inclined surface 36a whose height (axial height) gradually increases in the circumferential direction.
[0041]
On the other hand, on the surface of the rotating cam body 28 that overlaps with the sliding-type clamping member 27, a pair of drive cam sections 37 that form a pair with the driven cam section 36 of the sliding cam body 27 are formed on both sides of the shaft center. Has been. The drive cam portion 37 also includes an inclined surface 37a whose height in the axial direction gradually changes.
[0042]
Therefore, the rotating cam body 28 rotates slightly less than 90 degrees, so that a pressing force acts on the sliding-type clamping member 27 and a clamping state in which the sliding-type clamping member 27 is strongly pressed (locked state). It can be switched to a relaxed state (free state). The rotating cam body 28 is formed with a first stopper 28a that contacts the flange of the bearing fitting 26 in the clamped state and a second stopper 28b that contacts the flange of the bearing fitting 26 in the relaxed state.
[0043]
A substantially oval engagement groove 38 extending in a direction orthogonal to the axis is formed on the outer end surface of the rotating cam body 28. On the other hand, an engaging projection 39 that fits in the engaging groove 38 of the rotating cam body 28 is formed in the middle of the lock shaft 24.
[0044]
Therefore, the lock shaft 24 is held so as not to move toward the bearing fitting 26, and the rotating cam body 28 can be rotated integrally with the lock shaft 24. The lock shaft 24 and the rotating cam body 28 are not limited to the combination of the engagement groove 38 and the engagement protrusion 39, and may be rotated integrally by other engagement means.
[0045]
Needless to say, the lever 25 is attached to the lock shaft 24 so as not to be relatively rotatable. Note that a lever may be formed by bending the outer end of the lock shaft 24 into an L shape, and a knob may be provided at the tip.
[0046]
The tip of the lock shaft 24 opposite to the lever 25 protrudes outside the bearing fitting 26, and a flat washer 40 and a group of disc spring washers 29 are fitted into the overhang portion, and the flat washer 40 and disc spring washer are fitted. 29 is clamped to the side plate 26a of the bearing fitting 26 by a lock nut (double nut) 41.
[0047]
The group of Belleville spring washers 29 are arranged so that adjacent ones are in opposite postures. This is because the group of disc spring washers 29 is elastically deformed by tightening the lock nut 41. The elastic means is not limited to the disc spring washer 29, and other elastic bodies such as a coil spring and rubber can be used.
[0048]
As can be understood from the above description, in the relaxed state of FIG. 10A, the pressing action of the rotating cam body 28 does not act on the sliding cam body 27, so the friction plate group 23 freely moves back and forth. Thus, the first support shaft 9 can freely move back and forth, and the backrest 3 can freely tilt.
[0049]
On the other hand, when the lever 25 is operated to rotate the rotating cam body 28 to a clamping state as shown in FIG. 10B, the sliding type clamping member 27 is moved by the rotating cam body 28 to the flange of the fixed clamping member 33. By being pushed by 33a , the friction plate group 23 is clamped so as to be in close contact with each other, and the lock shaft 24, the sliding clamp member 27, and the fixed clamp member 33 are held incapable of relative movement, As a result, the friction plate group 23 is held immovable. For this reason, the 1st spindle 9 will be in the locked state which cannot move back and forth, and the backrest 3 will also be hold | maintained so that tilting is impossible.
[0050]
(3). Assembly of the locking device (Figs. 13-14)
In the present embodiment, as a procedure for assembling the lock device 19, the lock device 19 is assembled in advance and unitized, and then the lock device 19 is fixed to the base 6 with screws, and then the intermediate member 8, the auxiliary bracket 10, and the friction plate group. The first support shaft 9 is inserted through the first support shaft 9 (the first support shaft 9 may be inserted through the friction plate 20 in a state where the locking device 19 is temporarily fixed with a screw, and then the screw 35 may be finally tightened . ).
[0051]
Then, in order to unit the locking device 19, as shown in separate plan view of FIG. 13, the friction plate group 23 with connecting the tip odor Te at Bush 31, the friction plate group 23 or the like to the lock shaft 24 The lock nut 41 is lightly screwed so that the members are not detached and the members are not detached.
[0052]
In this state, a certain amount of space is provided between the sliding cam body 27 so that the friction plate group 23 can be inserted into the bearing fitting 26 with the friction plate group 23 positioned outside the bearing fitting 26. It is in a state. The length L of the Bush 31 is set to a length that can be inserted into the interior of the bearing bracket 26.
[0053]
Then, as shown in FIG. 14, the lock shaft 24 is supported by inserting the fixed clamping member 33 into the bearing fitting 26 and shifting the sliding clamping member 27 to the outside of the bearing fitting 26. Fit into the left and right bearing holes 34 of the metal fitting 26.
[0054]
Next, by shifting the fixed clamping member 33 and the sliding cam body 27, the boss portions 33b and 27a of the fixed clamping member 33 and the sliding clamping member 27 are fitted into the bearing holes 34, respectively. Tighten the lock nut 41. Thereby, the locking device 19 is unitized except for the lever 25.
[0055]
Then, as shown in FIG. 6, the lock shaft 24 is fitted into the window hole 42 of the base 6 in an inclined posture, and then the bearing fitting 26 is overlapped on the bottom surface of the base 6 and screwed. The first support shaft 9 is inserted into the plate group 23, the intermediate member 8, and the auxiliary bracket 10, and finally the lever 25 is attached to the lock shaft 24.
[0056]
In this assembly, since the bearing hole 34 of the bearing fitting 26 is formed as a slit hole having an upward opening, the friction plate group 23 and other members are fitted in the lock shaft 24 in advance and attached to the bearing fitting 26. be able to. And since the operation | work which fits the friction board group 23 grade | etc., In the lock shaft 24 can be performed easily, the assembly operation | work of the locking device 19 can also be performed very easily.
[0057]
It is possible to form the bearing hole 34 of the bearing fitting 26 in a U-shape with an integral groove width, but in this case, another member for preventing the lock shaft from coming off is required. On the other hand , if the bearing hole 34 is formed in a keyhole shape as in the present invention, there is an advantage that the lock shaft can be held so as not to be pulled out without requiring a pressing member.
[0058]
The friction plate group 23 and other members are attached to the lock shaft 24, while the bearing fitting 26 is fixed to the base 6 in advance, and the lock shaft 24 is attached to the bearing fitting 26 with the friction plate group 23 and the like. It is also possible to assemble the lock device 19 by fitting.
[0059]
(4). Inserting the first spindle 9 (FIGS. 15 to 17)
Prior to the mounting of the locking device 19, the intermediate member 8 is attached to the swing frame 13 by the third shaft 14, and the locking device 19 is attached to the base 6 after the intermediate member 8 has been flipped up. The intermediate member 8 is tilted and rotated, and the first support shaft 9 is inserted.
[0060]
In this case, since the intermediate member 8 covers the base 6, when the intermediate member 8 is tilted, a person cannot touch the friction plate group 23. Therefore, in the present invention, consideration is given so that the first support shaft 9 can be easily inserted into the friction plate group 23 even if a person cannot touch the friction plate group 23. This point will be described with reference to FIGS.
[0061]
15 is a sectional view taken along line XV-XV in FIG. 5, and FIG. 16 is a sectional view taken along line XVI-XVI in FIG. 15. As can be understood from both figures, when the friction plate group 23 is fully retracted, the friction plate group 23 Since the center of gravity is located in front of the lock shaft 24, the rear portion of the friction plate group 23 hits against the rear top plate 26 c of the bearing fitting 26 and is held so as not to rotate.
[0062]
The friction plate group 23 in this state is not only rotated slightly, the axis 44 of Bush 31 is only lowered by a slight dimension E from the center line 45 of the elongated hole 7 of the base 6. Therefore, as an example of a guide means lure first shaft 9 to Bush 31 absorbs the displacement dimension E, to form a tapered portion 31d at the end portion of the hole in the Bush 31, an end portion of the first shaft 9 A chamfered tapered portion 9a is formed.
[0063]
Accordingly, as shown in FIG. 17, the first shaft 9 is plugged so that the intermediate member 8 and the base 6 as well as support brackets 10, the first shaft 9 is tapered part 9a, the Bush 31 by the 31d of the guide action As a result, the posture of the friction plate group 23 is changed so that the front portion thereof is lifted, and becomes concentric with the long hole 7 of the base 6. For this reason, the assembly of the locking device 19 and the intermediate member 8 by inserting the first shaft 9 can be performed very easily.
[0064]
The guide means lure first shaft 9 to Bush 31 may be employed only either one of the tapered portion 31d and the tapered portion 9a of the first shaft 9 of the Bush 31. In the present embodiment, the rear top plate 26c of the bearing fitting 26 also serves as the posture holding means described in the backrest 2. However, the front top plate 26b may be used as the posture holding means.
[0065]
Moreover, front and rear top plate 23b of the friction plate group 23 bearing bracket 26, thereby sliding contact with the lower surface of 23c is also possible, in this case, the axis 44 of Bush 31 center line of the elongated hole 7 of the base 6 Since it is the same height as 45, it is not always necessary to provide guide means on the first bearing fitting 26 and the first shaft 9.
[0066]
Various modes can be selected as the posture holding means (stopper means) of the friction plate group 23. However, when the top plates 26b and 26c of the bearing fitting 26 are used as in this embodiment, the number of members is suppressed and the locking device device is used. There is an advantage that the structure becomes simple.
[0067]
(5). Others The present invention can be embodied in various ways other than the above embodiment. For example, as a chair that synchronizes the seat and the backrest, there is a type in which the first axis does not move and the second axis is a slide axis. In this case, the second axis is a friction plate. Just insert it into the group.
[0068]
The clamping member (clamping means) that clamps the friction plate group is not limited to the end face cam as in the embodiment, but an outer peripheral face cam described in Patent Documents 1 and 2 or a screw mechanism can be used. Various modes can be selected such as adoption.
[0069]
Further, the friction plate group does not necessarily have to be attached to the slide shaft, and can be attached to, for example, a swing frame to which a backrest is attached. Alternatively, the friction plate group may be fixed to the base so as not to move, and a lock shaft provided on the seat or the intermediate member may be inserted into the friction plate group (in this case, the lock shaft moves) . .
[0070]
【The invention's effect】
According to the first aspect of the present invention, in assembling the locking device, the members such as the friction plate group can be fitted into the lock shaft in advance before the lock shaft is fitted into the bearing fitting. It can be easily attached to the lock shaft, and as a result, the trouble of assembling the lock device can be reduced.
Further, by forming the bearing hole in a keyhole shape and fitting the sliding-type clamping member and the fixed-type clamping member, there is an advantage that the lock shaft can be held without being pulled out without requiring a pressing member.
[0071]
According to the second aspect of the present invention, since the slide shaft can be easily inserted into the friction plate group even if the person cannot touch the friction plate group in the assembly work of the chair, the assembly of the chair is possible. The work efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a side view of a chair.
FIG. 2 is an exploded perspective view of a mechanism part of the chair.
FIG. 3 is a longitudinal side view of a chair.
FIG. 4 is a partially cutaway plan view of a mechanism portion of the chair.
FIG. 5 is a plan view of the locking device.
FIG. 6 is an exploded perspective view of the lock device and the base.
FIG. 7 is an exploded perspective view of members constituting the locking device.
FIG. 8 is an exploded perspective view of members constituting the locking device.
FIG. 9 is a separated perspective view of a rotating cam body and a lock shaft.
FIG. 10 is a side sectional view showing the operation.
11A is a cross-sectional view taken along the line AA in FIG. 5, and FIG. 11B is a cross-sectional view taken along the line BB in FIG.
12 is a cross-sectional view taken along the line XII-XII of FIG. 5 after assembly.
FIG. 13 is a separated plan view showing a procedure for assembling the lock device.
FIG. 14 is a plan view showing an assembling procedure of the locking device.
15 is a sectional view taken along line XV-XV in FIG.
16 is a sectional view taken along line XVI-XVI in FIG.
FIG. 17 is a diagram showing a state during assembly.
[Explanation of symbols]
1 leg 2 seat 3 backrest 6 base 9 first axis (slide axis)
DESCRIPTION OF SYMBOLS 13 Oscillation frame 16 Backward tilt support spring 19 Locking device 20 Friction plates 21, 22 washers 23 Friction plate group 24 Lock shaft 25 Lever 26 Bearing metal fitting 27 Sliding type pinching member constituting pinching means
27c Suridoshikikyo member of the key portion 28 pressure rotary cam body 30 first hole 31 Bed constitute means Mesh <br/> 32 second hole (long hole)
33 Fixed clamping member
33a Flange 34 of fixed clamping member Bearing hole

Claims (2)

A base mounted on legs, and supported the seat in the base, a backrest which can be post-tilt against the spring means, the locking device for switching the backrest and rear tilt non-locked state and the rear tiltable free state door are provided,
The locking device, the lock shaft and the friction plate group formed by superimposing a large number of friction plates, a lock shaft extending through the elongated hole formed in the friction plate group, at both sides of the friction plate group A bearing clamp that supports the friction plate group, a sliding pinching member that presses the friction plate group from one side, a fixed pressing member that supports the friction plate group from the other side, and the sliding pinching member And a lever to operate
By linking one of the friction plate group and the lock shaft to the tilting of the backrest, the backrest is switched between the locked state and the free state by the clamping and releasing of the friction plate group. ,
Further, the bearing bracket is provided with two bearing holes for supporting the lock shaft on both sides of the friction plate group, and both the bearing holes are arranged so that the lock shaft is in a direction perpendicular to the axis. the moved cut open with a by cormorants opening can fit in are formed in the hole,
In the configuration
The sliding pinching member has the lock shaft penetrated and is slidably and non-rotatably fitted into one bearing hole, while the fixed pinching member has the lock shaft penetrating therethrough. It fits in the other bearing hole in a state where it cannot move to the outside of the bearing bracket, so that the sliding clamping member slides by the rotation of the lock shaft, and the friction plate group is clamped and released. And
Further, both the bearing holes of the bearing fitting have a keyhole shape in which the width of the opening is smaller than the inner diameter, and the sliding type pressing member is slidably fitted into the opening of one of the bearing holes. On the other hand, the fixed clamping member has a flange that abuts the inner surface of the bearing fitting and supports the friction plate group, and the fixed clamping member has both bearing holes. It has become a length that can be fitted between,
Chair. The base is formed in a box-like upward opening having a right and left side plates, the long hole formed in the base of the left and right side plates, the sliding axes of the right and left longitudinal moving substantially in the longitudinal direction in conjunction with the backrest insert While being
The lock shaft is disposed inside the base so as to extend parallel to the slide shaft,
A bush through which the slide shaft passes is inserted through the friction plate group,
Furthermore, in the bearing bracket or the base, the friction plate group posture holding means for holding the bushing in long hole concentrically or a state close thereto of the base is provided before insertion of the slide shaft,
The chair according to claim 1.