JP4518648B2 - Chair armrest equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an armrest device for a chair that can optimally adjust the position of an armrest with respect to a sitting body in accordance with the physique of a person who sits down, work contents, and the like.
[0002]
[Prior art]
The position of the elbow support can be changed by adjusting the position of the elbow rest according to the work content, such as the position of the arm according to the body shape (shoulder width or arm length) of the person sitting, operating the keyboard or mouse of a personal computer etc. It is important to improve work efficiency and fatigue.
[0003]
As described above, as a conventional chair that can adjust the position of the elbow rest, for example, as disclosed in JP-A-9-313301, JP-A-11-346873, etc. The elbow rest can be rotated in the left-right direction, such as those that are movable in the front-rear and left-right directions, and those disclosed in JP-A-10-42999, JP-A-9-121975, etc. There are things.
[0004]
[Problems to be solved by the invention]
In any of the above-described conventional armrest devices, guide means such as a long hole for guiding the movement and rotation of the elbow rest in the left-right direction are provided on the elbow rest side. The range must be set within the area of the width of the armrest, and therefore cannot be pivoted greatly in the left-right direction.
[0005]
Therefore, the present applicant provides an armrest device that can support the elbow with a more comfortable posture by increasing the pivotable range of the elbow rest by separately providing the elbow rest pivoting mechanism and the longitudinal movement mechanism. I am drafting.
[0006]
This is to provide an elbow support on the top of the armrest support so that it can rotate around the vertical axis, and to provide an elbow support on the upper part of the elbow support so that it can be moved back and forth. Such issues remain.
[0007]
That is, when the elbow rest support is rotated together with the elbow rest, an offset load acts on the vertical shaft, and the elbow rest support and the vertical shaft may be biased to make the rotation unsmooth.
[0008]
In addition, in order to prevent the elbow rest from rotating unnecessarily, it is necessary to provide means for imparting a resistance force to the rotation of the elbow rest support around the vertical axis and to hold it at an arbitrary rotational position. However, there is a problem of how to make the elbow rest support elastically held at a desired rotational position by using this as a simple configuration.
[0009]
The present invention has been made in view of the above problems, and enables the elbow rest to be rotated stably and smoothly, and the elbow rest support body is securely held in a desired rotational position by simple means. It is an object of the present invention to provide an armrest device for a chair that can be used.
[0010]
[Means for Solving the Problems]
According to the present invention, the above problem is solved as follows.
(1) At the top of the armrest strut that stands up from the side of the seat, an armrest support that supports the armrest substantially horizontally is provided so as to be rotatable about the vertical axis, and the top of the armrest strut and the armrest support. In an armrest device for a chair, in which an elastic holding means that can elastically hold an elbow rest support in a predetermined angle stepwise between the body and the body is provided, the elastic holding means is arranged so that the top of the armrest post is substantially horizontal. together with the vertical shaft provided upright on the substrate to penetrate Nasu, wherein the detent against one of the opposing surfaces of the substrate and the elbow support armrests strut, and a circle centered on the vertical axis a plurality of elongated grooves are formed angular retaining plate facing the radial direction on the peripheral, elastic plate material the vertical shaft passes, extends so as to face in opposite directions around a vertical axis, and the plurality of long grooves Selectable elastic engagement with And at least one pair of elastic pieces having a projection at the tip, and the pair of elastic pieces is provided in a groove provided on either one of the opposing surfaces of the armrest strut substrate and the elbow rest support. The angle holding plate and the elastic plate material are clamped by the base plate and an elbow support attached to the vertical shaft.
[0011]
( 2 ) In the above item (1 ) , a plurality of pins project from one of the outer peripheral ends of the opposing surfaces of the top substrate of the armrest strut and the elbow rest support, The angle holding plate is prevented from rotating by fitting an engaging groove formed on the outer peripheral portion of the holding plate.
[0012]
( 3 ) In the above item (1) or (2) , an anti-rotation pin for the angle holding plate and an arc-shaped fitting that is slidably fitted between the elbow rest support and the elbow rest support. Rotation angle restricting means for restricting a rotation range around the vertical axis of the elbow rest support formed of a guide groove is provided.
[0013]
( 4 ) In any one of the above items (1) to ( 3 ), the elbow rest is provided on the elbow rest support so that the longitudinal position can be adjusted.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of a chair (A) to which the present invention is applied. The chair (1) is tilted slightly forward from both left and right sides (hereinafter, the direction will be described with the left side of FIG. 1 as the front). The armrest device (3) of the present invention is provided at the upper end of the pair of armrest struts (2) that stand up.
[0015]
The armrest (4) of the armrest device (3) can adjust the position in the front-rear direction and the rotation angle in the left-right direction.
[0016]
2 to 10 show details of the armrest device (3). Since the left and right armrest devices (3) are symmetrical and have the same configuration, only the right side is described below, and the left side is omitted.
[0017]
Further, the height adjusting mechanism incorporated in the armrest strut (2) is not directly related to the present invention, and thus detailed description thereof is omitted.
[0018]
First, the rotation mechanism of the elbow rest (4) will be described.
As shown in FIGS. 2 to 4, a horizontal disk-shaped substrate (6) is fixed to the top surface of the lifting / lowering rod (5) in the armrest strut (2) that is circular in plan view, and its center A vertical shaft (7) and a pair of short front and rear pins (8) and (8) are erected on the outer peripheral ends.
[0019]
On the upper surface of the substrate (6), as shown in FIG. 4, a disk-shaped angle holding plate (9), an elastic plate material (10), a circular holder (11), and a lower end portion are circular. And the ellipse pad support body (12) which made the upper part the ellipse extended ahead from the circular lower end part is mounted in order from the lower part so that the vertical axis (7) may penetrate.
[0020]
The angle holding plate (9) is formed of acetal resin or the like, and engaging grooves (13) (13) formed on the front and rear outer peripheral surfaces thereof are fitted to a pair of pins (8) of the substrate (6). As a result, rotation around the axis is prevented.
[0021]
On the left and right upper surfaces sandwiching the engagement groove (13) in the angle holding plate (9), a plurality of (for example, seven) long grooves (14) facing the radial direction on the circumference around the vertical axis (7). Are formed at regular intervals (for example, 15 ° intervals) in the circumferential direction.
[0022]
The elastic plate member (10) is formed by punching a spring plate, and a pair of elastic pieces (10a) (10a) extending obliquely downward in the diameter direction are opposed to the outer peripheral edge of the ring-shaped portion by 180 °. Are arranged in a row. A hemispherical protrusion (15) bulging downward is formed at the tip of both elastic pieces (10a). One or more pairs of elastic pieces (10a) may be provided.
The lower surfaces of both projections (15) can be engaged with any of the plurality of long grooves (14) of the angle holding plate (9).
[0023]
On the lower surface of the holder (11) made of synthetic resin, as shown in FIG. 5, there is an upward concave groove (16) that is substantially complementary to that of the elastic plate (10) that can be accommodated, and closer to the outer peripheral portions on both sides thereof. In addition, a pair of arc-shaped guide grooves (17) and (17) are formed in which the upper ends of the pins (8) of the substrate (6) can be loosely fitted.
[0024]
Both guide grooves (17) are symmetrical with respect to the center line that bisects the concave groove (16), and their circumferential length is such that each pin (8) is within the guide groove (17). It is set so that it can be rotated approximately 90 °.
[0025]
A plurality of protrusions (18) are formed on the circular lower surface of the elbow rest support (12) made of synthetic resin, and the protrusions (18) are formed in the plurality of recesses (19) on the upper surface of the holder (11). By fitting, the elbow rest support (12) and the holder (11) are positioned and prevented from rotating relative to each other.
[0026]
A bushing (21) in which a guide cylinder (20) is press-fitted into the vertical hole (12a) drilled in the center of the lower end of the elbow rest support (12) and fitted to both upper and lower ends thereof The vertical axis (7) is inserted through the.
[0027]
The angle holding plate (9), the elastic plate (10), the holder (11) and the elbow support (12) are small diameters at the upper end of the vertical shaft (7) protruding above the elbow support (12). The nut (25) is screwed onto the male thread portion (22) via a wave washer (23) and a flat washer (24), thereby being mounted on the substrate (6).
[0028]
At this time, the wave washer (23) is in contact with the upper end of the bush (21) inserted through the vertical shaft (7) and fitted into the guide tube (20), and is pressed by the flat washer (24) to be elastically deformed. It is supposed to be made.
[0029]
As shown in FIG. 3, this is because the elastic pieces (10a) of the elastic plate (10) accommodated in the holder (11) are elastically deformed slightly upward by the elastic force of the wave washer (23), so that the elbow rest In order to elastically hold the support (12) by the wave washer (23) and the elastic plate (10), the protrusion (15) of the elastic piece (10a) is connected to the long groove (14) of the angle holding plate (9). This is to provide an appropriate resistance force in the rotating direction when engaged.
[0030]
As shown in FIG. 5, the assembly phase of each pin (8) of the substrate (6) and the guide groove (17) of the holder (11) is a center line (L ₁ ) that bisects both guide grooves (17). Are phase shifted by approximately 30 ° clockwise with respect to the center line (L ₂ ) that faces the front-rear direction connecting the centers of the pins (8), and at this time, the protrusions ( 15) engage with the second long groove (14) facing each other by 180 ° (see FIG. 12). With such a positional relationship, the holder (11) and the elbow rest support (12) integrated therewith are approximately 15 ° clockwise and approximately 75 ° counterclockwise with respect to each pin (8). It can be rotated around the vertical axis (7).
[0031]
Moreover, when it is in the said positional relationship, the above-mentioned elbow pad (4) attached to an elbow pad support body (12) will be a normal use position, ie, a position straight in the front-back direction.
[0032]
Next, the back-and-forth movement mechanism of the elbow rest (4) will be described.
As shown in FIGS. 2 and 3, a channel-shaped elbow rest bracket (26) facing in the front-rear direction is screwed to the upper part in the elbow rest support (12), and both horizontal directions facing in the left-right direction at the upper end thereof. A pair of left and right selectors (27) and (27) having the same shape as shown in FIG. 6 are fitted to the pieces (26a) and (26a) symmetrically.
[0033]
Each selector (27) is formed of acetal resin or the like, and has a base piece (27a) fitted on the outer edge of the horizontal piece (26a), and an L-shape in a plan view from its front and rear edges. A pair of front and rear foot pieces (27b) (27b) that are inwardly connected and abutted with the upper surface of the horizontal piece (26a) at the time of installation are connected to the tip portions of both foot pieces (27b). The arc-shaped piece (27c) bulging outward in an arc shape connected to the upper surface of the arc-shaped piece (27c) is formed on the outer surface of the central portion of the arc-shaped piece (27c). ing.
[0034]
The arc-shaped piece (27c) and both leg pieces (27b) supporting the arc-shaped piece (27c) can be slightly elastically deformed so that the protrusion (28) can move in the left-right direction.
[0035]
Both horizontal pieces (26a) of the elbow rest bracket (26) and the base piece (27a) of the selector (27) fitted thereto are inwardly U-shaped at the left and right ends of the movable plate (29) facing in the front-rear direction. Are fitted in a pair of guide rails (30), (30) that are movable relative to each other (see FIG. 2).
[0036]
The elbow rest (4) is composed of a synthetic resin upper surface plate (4a) having a substantially rectangular shape in plan view that is long in the front-rear direction, and a screw (31) fixed so that a slight space is formed on the lower surface. The lower surface plate (4b) is made of a resin, and a rectangular upward recess (32) that is long in the front-rear direction is formed at the center of the lower surface plate (4b).
[0037]
As shown in FIGS. 7 and 8, a rectangular hole (33) facing in the front-rear direction is formed in the central portion of the top wall (32a) of the recess (32) in the bottom plate (4b), and is opposed to the left and right thereof. A plurality of (for example, seven) corrugated locking grooves (34) are formed on the inner surface so as to face each other.
[0038]
In the recess (32) of the lower surface plate (4b), the movable plate (29) is connected to the engagement pieces (29a) (29a) on the left and right sides of the rear end thereof in the recess (32). It is fixed by being inserted into (35) and locked, and the front end mounting piece (29b) is fixed to the step (32b) in the recess (32) with a screw (31).
[0039]
A rectangular hole (29c) larger than the rectangular hole (33) of the lower surface plate (4b) is formed in the central portion of the movable plate (29), and both locking concave grooves (34) formed in the rectangular hole (33) are formed. ) Is exposed to the inside of the rectangular hole (29c) (see FIGS. 7 and 8).
[0040]
When the lower plate (4b) is fixed to the movable plate (29), as shown in FIG. 8, each arcuate piece (27c) in the pair of left and right selectors (27) attached to the elbow rest bracket (26) The hemispherical protrusion (28) formed on the rectangular hole (33) of (4c) and protruding above can be elastically engaged with any of the plurality of locking grooves (34).
[0041]
That is, when the lower surface plate (4b) is fixed to the movable plate (29), the elbow rest (4) can move in the front-rear direction with respect to the elbow rest support (12), and the protrusions on the left and right selectors (27). By selectively engaging (28) with any of the locking grooves (34), the position of the elbow rest (4) in the front-rear direction can be adjusted stepwise. When the elbow rest (4) is moved to the front / rear limit position, the front / rear end lines of the arc-shaped piece (27c) in both selectors (27) contact the front / rear end faces of the rectangular hole (33) of the bottom plate (4b). Since it touches, it does not move back and forth any further.
[0042]
As shown in FIGS. 2, 3 and 10, a pair of front and rear covers (36) made of synthetic resin are fixed to the lower end opening surface of the recess (32) in the lower surface plate (4 b), and the elbow rest When (4) is moved in the front-rear direction, fingers and the like are prevented from entering the recess (32) and being pinched between the elbow rest support (12).
[0043]
As shown in FIG. 9 (only one of them is shown in the front-rear symmetry), each cover (36) is moved by a nut (25) screwed to the vertical shaft (7) at the center and both left and right sides. Are formed in the front and rear clearance grooves (37) and slit-shaped clearance grooves (38) that allow the left and right vertical pieces of the elbow rest bracket (26) to move, and on the left and right side edges. A pair of front and rear engaging pieces (39) facing each other are provided so as to protrude upward.
[0044]
Eight engagement holes (40) in which the engagement pieces (39) are formed at the peripheral edge of the recess (32) of the lower surface plate (4b) so that the opposing ends of both covers (36) are abutted. (Refer to FIGS. 7 and 8), the locking protrusion (39a) formed on the outer surface of each engagement piece (39) is inserted into the locking hole (40) by being elastically deformed slightly inwardly. It is elastically engaged with the upper edge of the lens and is prevented from coming off.
[0045]
In the armrest device of the above embodiment, when the elbow rest (4) is grasped by hand and pushed strongly in the front-rear direction, a pair of left and right selectors (27) relatively move in the front-rear direction as shown in FIG. As a result, the foot piece (27b) is elastically deformed, and the protrusion (28) of each arcuate piece (27c) is detached from the left and right engaging grooves (34) of the bottom plate (4b) of the elbow rest (4). Then, it is elastically engaged with other appropriate locking grooves (34).
[0046]
Thereby, the position of the elbow rest (4) in the front-rear direction can be adjusted step by step by the number of the locking grooves (34).
[0047]
On the other hand, when the elbow rest (4) is rotated and the interval between the left and right elbow rests (4) is adjusted, it is performed as follows.
[0048]
As shown in FIG. 12, when the entire elbow rest (4) in the normal use position indicated by the solid line is gripped from above and rotated clockwise in plan view (left elbow rest is counterclockwise), the elbow rest ( 4) The elastic plate material (10) held in the elbow rest support (12), the holder (11) and the concave groove (16) of the holder (11) is attached to the angle holding plate (9). It rotates around the vertical axis (7). Then, each pin (8) fitted in the guide groove (17) of the holder (11) is brought into contact with the end of the guide groove (17) opposite to the rotation direction, as indicated by an imaginary line. By relative movement until contact, the elbow rest (4) can be rotated by approximately 15 °.
[0049]
At this time, the pair of protrusions (15) of the elastic plate member (10) is elastically engaged with the longest groove (14) at the end facing 180 ° on the side close to each pin (8). Therefore, the elbow rest (4) does not rotate in a counterclockwise direction from that position.
[0050]
Thus, when the elbow rest (4) is rotated by 15 ° clockwise, as shown in FIG. 13, when operating the mouse (M) such as a personal computer, the elbow of the seated person is optimally ergonomically. It can be supported in a stable state.
[0051]
On the other hand, when the elbow rest (4) is rotated counterclockwise from the normal use position (the left elbow rest is clockwise), as shown in FIG. 12, each pin (8) is guided into the guide groove (17). By relatively moving the inside until it comes into contact with the opposite end, the elbow rest (4) can be rotated up to about 75 ° at the maximum.
[0052]
Within this rotation range, if the pair of protrusions (15) of the elastic plate (10) are sequentially elastically engaged with the long grooves (14), the elbow rest (4) is gradually stepped by about 15 °. The rotation can be stopped.
[0053]
Thus, if the rotation area | region of the armrest (4) to a counterclockwise direction is expanded, according to the content of work, the armrest (4) can be adjusted to an optimal position.
In particular, as shown in FIG. 14, for example, when operating a keyboard (K) of a notebook type personal computer or the like, the left and right elbow pads (4) are largely rotated into a C-shape, and the seated elbow is placed on the keyboard ( K) can be supported in a wide range with a comfortable posture, and the feeling of fatigue can be reduced.
[0054]
As described above, in the above embodiment, the turning mechanism of the elbow rest (4) and the forward / backward movement mechanism are separated, and the elbow rest (4) is turned around the armrest strut (2). Therefore, the rotation range of the elbow rest (4) is not limited as in the conventional one in which the pivot of the elbow rest is performed at the armrest.
[0055]
In addition, a plurality of long grooves (14) facing the radial direction are provided on the upper surface of the angle holding plate (9), and the two protrusions (15) of the elastic plate (10) are elastically engaged with the long grooves (14). Even if a backlash occurs between the holder (11) and the elbow support (12) and the vertical shaft (7), and the protrusion (15) is displaced in the radial direction, the long groove (14) Since the displacement can be absorbed, the elbow rest (4) is securely held in a desired position. Moreover, since the two protrusions (15) opposed to each other by 180 ° are always in pressure contact with the angle holding plate (9), the vertical shaft (7) is not subjected to an offset load, and the elbow rest support (12) Can rotate smoothly in a balanced manner.
[0056]
Furthermore, a pair of left and right elastically deformable selectors (27) are attached to the elbow rest bracket (26) fixed to the elbow rest support (12), and each of the arcuate pieces (27c) formed in both selectors (27) is formed. Since the protrusion (28) can be elastically engaged with and disengaged from the left and right engaging grooves (34) provided at the center of the bottom plate (4b) of the elbow rest (4), The front and rear positions of the abutment (4) can be adjusted stepwise with moderation, and the elbow rest (4) can be stably moved back and forth without rattling in the left-right direction.
[0057]
Since the cover (36) is fixed to the recess (32) formed in the bottom plate (4b) of the elbow rest (4), even if the elbow rest (4) is inadvertently moved back and forth There is no possibility that a finger or the like is sandwiched between the front and rear edges of the recess (32) and the elbow rest support (12), and foreign matters such as dust enter the recess (32).
[0058]
In the above embodiment, to secure the angles holding plate (9), although by rotating the elastic plate (10) side, or them as opposite.
That is, the angle holding plate (9) and the elastic plate material (10) are turned upside down, the angle holding plate (9) is fixed to the holder (11), and the elastic plate material (10) is rotated to the substrate (6). What is necessary is just to fix as impossible.
[0059]
In addition, the pin (8) and the guide groove (17) constituting the rotation angle restricting means are also turned upside down, the pin (8) is in the holder (11), and the guide groove (17) is in the substrate (6). You may make it provide.
[0060]
The holder (11) is not necessarily required. If the concave groove for accommodating the elastic plate (10) and the guide groove for the pin (8) are directly provided on the lower surface of the elbow support (12), the holder (11) Can be omitted.
The elbow rest (4) is composed of an upper surface plate (4a) and a lower surface plate (4b). However, as an elbow rest (4) with an integral structure, the same locking recess as described above is formed in the recess formed on the lower surface. A groove (34) may be provided.
[0061]
By changing the circumferential length of the guide groove (17) and the phase of the pin (8) and the guide groove (17) according to the purpose of use of the chair, the armrest (4) can be turned in the left-right direction. Of course, the moving range can be set arbitrarily.
[0062]
【The invention's effect】
According to the first aspect of the present invention, since the projections provided on the pair of elastic pieces are always in pressure contact with the angle holding plate, the elbow rest support is elastically held in a well-balanced manner, and an offset load acts on the vertical axis. There is nothing. Therefore, the elbow rest can be stably and smoothly rotated.
In addition, since the protrusion of the elastic piece is elastically engaged with the long groove facing in the radial direction, an irregularity occurs between the elbow rest support and the vertical axis, and the protrusion is displaced in the radial direction. Even if it does, since a long slot absorbs the position shift, an elbow rest is certainly elastically held in a desired position.
Furthermore, since the structure of the elastic holding means is simple, its vertical dimension can be reduced and it can be implemented at low cost.
Further, the pair of elastic pieces are extended to an elastic plate material penetrating the vertical axis so as to face opposite directions around the vertical axis, and the protrusions of the elastic pieces are angle holding plates at positions away from the vertical axis. The elbow rest support is held in a more balanced manner.
Since the pair of elastic pieces are housed in a concave groove provided on either of the opposing surfaces of the armrest support substrate and the elbow support, the elastic pieces can be easily positioned and assembled. Become.
[0063]
According to the second aspect of the invention, positioning and assembling of the angle holding plate are facilitated.
[0064]
According to the invention described in claim 3 , the elbow rest support can be freely rotated within the range of the rotation angle regulating means without being restricted by the width of the elbow rest, etc. The direction can be optimally adjusted according to the work content.
[0065]
According to the invention of claim 4 , the elbow rest can be moved not only in rotation but also in the forward and backward directions. By combining them, the position of the elbow rest is adjusted more optimally according to the work contents and the like. be able to.
[Brief description of the drawings]
FIG. 1 is a side view of a chair to which the present invention is applied.
FIG. 2 is a partially cut-away vertical side view of an armrest strut provided with an embodiment of the present invention.
3 is an enlarged longitudinal front view taken along the line III-III in FIG.
4 is an exploded perspective view of an elbow rest turning mechanism. FIG.
FIG. 5 is also a bottom view of the holder.
FIG. 6 is also a perspective view of an elbow rest bracket and a selector attached thereto.
FIG. 7 is also a bottom view of the elbow rest.
FIG. 8 is a partially cutaway plan view of the elbow rest bracket attached to the elbow rest.
FIG. 9 is a perspective view of the cover in the same manner.
10 is also a longitudinal sectional front view taken along line XX of FIG. 2. FIG.
FIG. 11 is also a partially cutaway plan view when the position of the elbow rest is adjusted before and after.
12 is a plan view showing the positional relationship between the pin and the guide groove and the rotation range of the elbow rest when FIG. 2 is viewed transversely along the line XII-XII. FIG.
FIG. 13 is a schematic plan view showing an example of operating a mouse of a personal computer by rotating an elbow pad outward.
FIG. 14 is a schematic plan view showing an example in which the keyboard of a small personal computer is operated by largely rotating the elbow rest inward.
[Explanation of symbols]
(1) Seat
(2) Armrest support
(3) Armrest device
(4) Elbow rest
(4a) Top plate
(4a) Bottom plate
(5) Lifting rod
(6) Board
(7) Vertical axis
(8) Pin
(9) Angle holding plate
(10) Elastic plate material
(10a) Elastic piece
(11) Holder
(12) Elbow rest support
(13) Engaging groove
(14) Long groove
(15) Protrusion
(16) Groove
(17) Guide groove
(18) Projection
(19) Recess
(20) Guide tube
(21) Bush
(22) Small diameter male thread
(23) Wave washer
(24) Flat washer
(25) Nut
(26) Elbow rest bracket
(26a) Horizontal piece
(27) Selector
(27a) Base piece
(27b) Foot piece
(27c) Arc piece
(28) Protrusion
(29) Movable plate
(29a) Locking piece
(29b) Mounting piece
(30) Guide rail
(31) Screw
(32) Recess
(32a) Top wall
(32b) Step
(33) Rectangular hole
(34) Locking groove
(35) Engagement hole
(36) Cover
(37) (38) Escape groove
(39) Engagement piece
(39a) Locking ridge
(40) Engagement hole
(A) Chair
(K) Keyboard
(M) Mouse

Claims (4)

An armrest support that supports the armrest substantially horizontally is provided on the top of the armrest strut standing up from the side of the seat so as to be rotatable about the vertical axis, and the armrest strut and the armrest support In the armrest device of the chair provided with an elastic holding means that can elastically hold the elbow rest support in a predetermined angle stepwise, the elastic holding means is provided on a substrate that is substantially horizontal at the top of the armrest post. together with the vertical shaft which is erected to penetrate the the detent against one of the opposing surfaces of the substrate and the elbow support armrests strut, and on the circumference around the vertical axis an angle holding plate having a plurality of elongated grooves are formed facing the radial direction, the elastic plate where the vertical axis passes, extends so as to face in opposite directions around a vertical axis, and selectively and the plurality of long grooves Elastically engageable And at least one pair of elastic pieces having a raised portion at the tip, and the pair of elastic pieces is accommodated in a concave groove provided on either one of the opposing surfaces of the armrest strut substrate and the elbow support. The armrest device for a chair is characterized in that the angle holding plate and the elastic plate member are sandwiched between the substrate and an armrest support attached to the vertical shaft. In one of the outer peripheral edge portion in the opposing face each other between the substrate and the elbow support at the top of the armrest pillar, projecting a plurality of pins, this pin engagement formed on the outer peripheral portion of the angle-maintaining plate by fitting the groove, around the angle holding plate fastened claims 1 Symbol placement of chair armrest device. Around the vertical axis of the elbow rest support comprising an anti-rotation pin for the angle holding plate and an arcuate guide groove into which the pin is slidably fitted between the elbow rest support and the elbow rest support. The armrest device for a chair according to claim 1 or 2, further comprising a rotation angle regulating means for regulating the rotation range of the chair. The armrest device for a chair according to any one of claims 1 to 3 , wherein the armrest is provided on the armrest support so that the position of the armrest can be adjusted.

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