HK1098021A - Elbow rest and chair - Google Patents

Description

Armrest and chair

Technical Field

The present invention relates to an armrest configured to be able to horizontally rotate an elbow rest (elbow brace) with respect to an elbow strut according to a posture of a seated user, and a chair configured to attach the armrest to a predetermined portion.

Background

Conventionally, there is known an armrest which includes an elbow rest for resting an elbow of a seated person and an elbow strut for pivotally supporting the elbow rest, and which is configured to be horizontally rotatable about a pivot point between the elbow rest and the elbow strut in accordance with a posture of the seated person to use, and which is capable of appropriately changing an orientation of the elbow rest in a longitudinal direction (see, for example, patent document 1). In the armrest in which the toggle rest is horizontally rotatable with respect to the toggle strut, in order to stop the toggle rest at an appropriate angle and obtain resistance having an appropriate vibration feeling when the angle is changed, for example, there may be considered a configuration in which a stop mechanism is provided which includes a cylindrical pin as a fitting member provided to protrude from an upper end portion of the toggle strut, and a movable member provided on the side of the toggle rest, which moves while bringing an outer peripheral surface into contact with the pin in accordance with the rotational operation of the toggle rest, and which has a plurality of stop engagement recesses formed intermittently on the outer peripheral surface and engageable with the pin. The movable member is provided between the pivot point and the pin on the side of the center angle of an arc having a radius of a line segment connecting the pivot point and the pin, and is capable of moving back in a direction approaching or separating from the pivot point along the longitudinal direction of the toggle rest, and a spring for assisting the forward and backward movement is provided on the side of the pivot point. The spring is extended when the pin is fitted in the pause engagement recess in accordance with the rotation of the toggle holder, and is contracted when the pin passes over a peak between the pause engagement recesses, thereby linearly moving the movable member.

Disclosure of Invention

However, since the spring is provided closer to the pivot point than the pin fixed to the toggle link as described above, the rotation angle of the toggle rest capable of effectively exhibiting the expansion and contraction function of the spring is restricted. In other words, even if the pin is fitted into the stop engagement recess of the movable member at a large angle (for example, an angle perpendicular to the expansion and contraction direction of the spring) with respect to the expansion and contraction direction of the spring, the spring cannot be expanded and contracted satisfactorily, and therefore the toggle rest cannot be rotated beyond a predetermined angular range in which the spring can be expanded and contracted normally. This is because the stop engagement recess is formed in the outer peripheral surface of the movable member that rotates together with the toggle rest, and therefore the advancing and retreating direction of the movable member, that is, the extending and contracting direction of the spring, and the engagement direction of the pin with the stop engagement recess of the movable member sequentially change with the rotation of the toggle rest. On the other hand, in order to improve the stability of the pivot support state of the elbow strut and the toggle bracket, it is preferable to set the distance between the pivot point and the pin to be large, but there is a problem that the pin cannot be set to exceed the side edge of the toggle bracket extending in the longitudinal direction, and the distance between the pivot point and the pin is limited by the width dimension of the toggle bracket. Further, if the distance between the pivot point and the pin is set to be small regardless of the stability of the pivot support state of the elbow strut and the toggle rest, it is considered that the rotation angle of the toggle rest based on the positional relationship between the pin and the pivot point can be set to be relatively large, but the rotation angle range of the toggle rest is substantially limited due to the restriction based on the arrangement position and the extending/contracting direction of the spring.

Therefore, in the conventional armrest, the rotation angle range of the elbow rest is limited to a very small value due to the above two problems.

The present invention has been made in view of the above problems, and a main object of the present invention is to provide an armrest in which the rotation angle of an elbow rest with respect to an elbow strut is not limited by a stop mechanism, and the rotation range of the elbow rest can be freely set.

That is, the armrest of the present invention includes an elbow rest for resting an elbow of a seated person, and an elbow support pivotally supporting the elbow rest, wherein the elbow rest is configured to be horizontally rotatable with a pivot point of the elbow rest and the elbow support as a fulcrum, and a stopping mechanism for stopping the elbow rest at a predetermined angle is provided between the elbow rest and the elbow support, and is characterized in that the stopping mechanism includes a stationary member having a plurality of stopping engagement elements on an outer peripheral surface thereof, and a movable member that rotates together with the armrest and has engagement elements that are sequentially elastically engageable with the plurality of stopping engagement elements, and the stationary member is attached to the elbow support side, and the movable member is attached to the elbow rest side.

In this case, since the stationary member having the plurality of stop engagement elements formed on the outer peripheral surface thereof is mounted on the elbow strut side, the movable member having the engagement elements which are sequentially elastically engaged with the stop engagement elements is mounted on the elbow rest side, the direction of the resilient engagement of the stop engagement elements of the engagement element and the stationary member is independent of the angle of rotation of the toggle support, the direction is always constant, the matching state of the matching element and the pause matching element can be well without being influenced by the rotation angle of the elbow support, the prior bad condition that the rotation angle of the elbow support is limited by the arrangement of the pause mechanism can be eliminated, in addition, if the outer peripheral surface of the stationary member to be brought into contact with the mating member is positioned in the vicinity of the side edge portion of the toggle rest, the stationary member can be enlarged to the maximum and the stability of the pivot support state of the elbow strut and the elbow rest can be improved. The term "elastic engagement" as used herein includes not only the elastic engagement using a spring described below, but also a concept in which the movable member itself is made of an elastically deformable material such as rubber and the elastic engagement of the movable member itself is used.

In a specific embodiment, the movable member includes the engaging element and a spring biasing device for biasing the engaging element toward the pivot point.

Further, if the rotation regulating mechanism for regulating the rotation angle of the elbow rest with respect to the elbow strut within a predetermined angle is provided, for example, the elbow rest can be rotated to the predetermined angle from a normal use position in which the longitudinal direction thereof substantially coincides with the front-rear direction of the chair, in accordance with the needs of the seated person, and therefore, the present invention is extremely excellent in practical applicability.

In particular, if the elbow rest is provided with a receiving portion capable of receiving the stationary member, and the rotation regulating mechanism includes a protrusion provided on one of the outer peripheral surface of the stationary member and the inner peripheral surface of the receiving portion, and a contact portion provided on the other and contacting the protrusion when the elbow rest rotates by a predetermined angle, further rotation of the armrest can be reliably regulated by contact between the protrusion and the contact portion. Further, since the stationary member is accommodated in the accommodating portion, the stationary member can be easily positioned with respect to the elbow rest, and the rotation regulating mechanism is configured by the accommodating portion and the stationary member in a close contact relationship, so that the function of regulating the rotation angle of the elbow rest can be effectively improved.

If a recessed groove having a recessed dimension substantially corresponding to the protruding dimension of the protruding portion is provided on one of the outer peripheral surface of the stationary member provided with the abutting portion or the inner peripheral surface of the housing member so that the protruding portion and the abutting portion do not interfere with each other during the operation of the armrest rotating within the predetermined angle, and both end portions of the recessed groove are used as the abutting portions, the rotation angle range of the elbow rest is directly reflected by the distance between the abutting portions, that is, the width dimension of the recessed groove or the center angle of the recessed groove.

In particular, if the angle formed by the line segment connecting the ends of the concave groove and the pivot point is set to be substantially equal to the sum of the angle formed by the line segment connecting the ends of the protrusion and the pivot point and the rotation angle of the elbow rest, the elbow rest can be rotated within a predetermined angle range with little play. Further, the angle formed by the line segment connecting each end of the groove and the pivot point, that is, the central angle of the groove can be easily set.

In order to effectively avoid the protrusion from being strongly contacted with the contact portion by the rotation operation of the elbow rest and from being damaged by the contact with the contact portion with a simple structure, the planar shape of the protrusion is preferably a fan shape.

In order to rotate the elbow rests within a sufficient range necessary for the usage form of the armrests, that is, between a normal usage position in which the longitudinal dimension of the elbow rests is aligned with the front-rear direction of the chair and a rotational usage position in which the longitudinal direction of the elbow rests is substantially aligned with the left-right direction of the chair, the rotation angle of the elbow rests may be set to substantially 90 degrees to sufficiently satisfy the user's needs. This makes it possible to relatively easily set the center angle of the concave portion.

On the other hand, in order to manufacture an armrest that can be used in both of the left and right elbow armrests, it is preferable that the rotation regulation range of the elbow rests and the rotation direction of the elbow rests relative to the elbow rests can be changed by changing the attachment direction of the stationary member to the elbow rests. In this case, the armrest for the left elbow and the armrest for the right elbow can be formed by a simple operation of changing the mounting direction of the stationary member, and the parts can be made more common than the armrest in which dedicated members must be provided for the left elbow and the right elbow, thereby contributing to reduction in the number of parts and cost.

Specifically, the stationary member may be attached to the elbow strut via an engagement mechanism including an engagement recess provided at one of a lower end portion of the stationary member and an upper end portion of the elbow strut, and an engagement projection provided at the other and engaged with the engagement recess, wherein the engagement recess and the engagement projection are engaged in any one of a plurality of attachment directions of the stationary member with respect to the elbow strut.

Further, if an angle formed by a line segment along one mounting direction and a line segment along another mounting direction different from the one mounting direction among the plurality of mounting directions of the stationary member with respect to the elbow strut is set to be substantially equal to the rotation angle of the elbow rest, the fitting concave portion and the fitting convex portion are fitted to each other by appropriately selecting the one mounting direction and the other mounting direction, so that the rotation regulation range of the elbow rest can be changed, and the rotation operation of the elbow rest with respect to the elbow strut in each fitting state can be reliably realized.

In addition, it is preferable that the planar shapes of the fitting concave portion and the fitting convex portion are set to a shape in which at least one fitting form in which the fitting concave portion and the fitting convex portion are fitted in the one mounting direction and another fitting form in which the fitting concave portion and the fitting convex portion are fitted in the other mounting direction can be selected, and in this case, as long as the planar shapes of the fitting concave portion and the fitting convex portion are regular polygonal shapes that substantially correspond to each other, the fitting concave portion and the fitting convex portion can be reliably fitted to each other in any mounting direction, and a good fitting state can be achieved. In particular, when the rotation angle of the elbow rest is set to substantially 90 degrees, the planar shape of the fitting concave portion and the fitting convex portion is set to a regular quadrilateral shape or a regular octagonal shape, so that the rotation angle of the elbow rest can be maintained at substantially 90 degrees, and the elbow rest can be favorably used as both the armrest for the left elbow and the armrest for the right elbow.

On the other hand, in order to adjust the height of the armrest as a whole in accordance with the body of the seated person, it is sufficient that the elbow strut is provided with a strut body that is disposed in an upright posture with a lower end portion fixed to the seat, and a cover member that is detachably fitted to the outside of the strut body, and a height adjustment mechanism that adjusts the installation height position of the cover member with respect to the strut body is provided between the strut body and the cover member.

Specific embodiments of the height adjusting mechanism include: the loading device comprises a matched part which is provided with a plurality of matching holes along the height direction, a matching part which is provided with a matching claw capable of being selectively matched with the matching holes, and a loading device which loads the matching part in the direction that the matching claw can be matched with the matching holes; and the engaging state of the engaging claw and the engaging hole can be released by a predetermined operating force.

In addition, as a chair provided with armrests that achieve the above-described effects, it is preferable that the armrests are provided in a pair so as to be bilaterally symmetrical with respect to the left and right end portions of the seat.

According to the armrest of the present invention, since the stationary member having the plurality of stop engagement elements formed on the outer peripheral surface is attached to the elbow strut side, and the movable member having the engagement elements that can be sequentially and elastically engaged with the plurality of stop engagement elements is attached to the elbow rest side, the direction of elastic engagement of the stop engagement elements of the engagement elements and the stationary member is always constant regardless of the angle of rotation of the elbow rest with respect to the elbow strut, and the engagement state between the engagement elements and the stop engagement elements can be always maintained well regardless of the angle of rotation of the elbow rest, and the range of rotation of the elbow rest can be freely set.

Drawings

Fig. 1 is an overall plan view of an armrest and a chair to which the armrest is applied, showing an embodiment of the present invention.

Fig. 2 is a partially exploded perspective view showing the armrest of the embodiment with a part thereof omitted.

Fig. 3 is a plan view of a base portion of an elbow rest constituting the armrest of the embodiment.

Fig. 4 is a side sectional view of the elbow strut of the armrest of the embodiment shown with a portion omitted.

Fig. 5 is a perspective view partially showing the stationary member and the upper end of the elbow strut in the embodiment.

Fig. 6 is an explanatory view of the armrest for the left elbow according to this embodiment.

Fig. 7 is an explanatory view of the armrest for the left elbow.

Fig. 8 is an explanatory view of the right elbow armrest according to this embodiment.

Fig. 9 is an explanatory view of the right elbow armrest.

Fig. 10 is a side sectional view showing a modification of the elbow strut and the height adjusting mechanism of the embodiment.

Detailed description of the preferred embodiments

An embodiment of the present invention will be described below with reference to the drawings.

The armrest E of the present invention is a member suitable for use in a chair C shown in fig. 1, for example.

First, the chair C will be described in detail with reference to the drawings, in which a seat S is supported on a plurality of spoke legs L via a support column, not shown, and a backrest B is mounted behind the seat S via a backrest stay a.

Armrests E are provided in pairs at both left and right end portions of the seat S so as to be bilaterally symmetrical.

As shown in fig. 2 and the like, the armrest E includes an elbow rest 1 for a seated person to rest thereon, and an elbow strut 2 for supporting the elbow rest 1 so as to be horizontally rotatable. Further, a stopping mechanism is provided to stop the elbow rest 1 at a predetermined angle so that a resistance having an appropriate vibration feeling can be obtained at the time of changing the angle. The stop mechanism is composed of a stationary member 3 and a movable member 4, as will be described later. In the following description, the front-rear direction of the elbow strut 2 corresponds to the front-rear direction of the chair C, and the "rear" in the elbow rest 1 means the backrest B side of the normal use positions LP and RP where the longitudinal direction of the elbow rest 1 is substantially aligned with the front-rear direction of the chair C, and the "front" means the backrest B side opposite to the normal use positions LP and RP (see fig. 1).

The elbow rest 1 is composed of a base part 5 and an elbow rest cover, not shown, attached to the upper end side of the base part 5.

As shown in fig. 2 and 3, the base part 5 is an integrally molded product mainly including a bottom part 51 having a substantially oblong shape in plan view, a peripheral wall 52 provided on a peripheral edge of the bottom part 51, a 1 st housing part 53 provided at a position slightly displaced rearward from a substantially central part in a longitudinal direction of the bottom part 51 and capable of housing the stationary member 3, and a 2 nd housing part 54 provided continuously on a rear side of the 1 st housing part 53 and capable of housing the movable member 4.

The 1 st housing part 53 is a member having a housing space 53S surrounded by an arc wall 531 which is open on the rear side and has a substantially partial arc shape in plan view. The arc wall 531 is connected to the peripheral wall 52 at both right and left side end portions thereof, and has a wall thickness within a predetermined angle on the front side smaller than that at the peripheral portion thereof. By thus forming the predetermined region of the arc wall 531 to be thin, the concave groove 532 is formed in the predetermined region of the inner peripheral surface of the arc wall 531. In the present embodiment, the central angle of the concave groove 532 is set to an angle slightly larger than 90 degrees. A through hole 53a penetrating the bottom surface portion 51 is formed in a substantially central portion of the 1 st housing portion 53. The through hole 53a is concentric with the inner peripheral surface of the arc wall 531 excluding the portion where the concave groove 532 is formed.

The 2 nd accommodating portion 54 is a member having a pair of opposing walls 541 connected to the rear side of the open arc wall 531 and extending in the longitudinal direction of the elbow rest 1, and an accommodating space 54S which is open at the front side by a connecting wall 542 connecting the opposing walls 541 and has a substantially square shape in plan view. The housing space 54S communicates with the housing space 53S of the 1 st housing part 53, and the facing walls 541 are provided with horizontal pieces 541a that horizontally protrude in directions to approach each other from a substantially central position in the height direction.

Further, the hole edge portions 511 are provided in the vicinity of both longitudinal end portions of the bottom surface portion 51, and the hole edge portions 511, the peripheral wall 52, the arc wall 531, the opposing wall 541, and the connecting wall 542 are connected to each other via the ribs arranged substantially in a matrix shape, whereby the strength and shape retention of the entire base portion 5 can be effectively improved.

The stationary member 3 and the movable member 4 accommodated in the accommodating portions 53 and 54 will be described later.

On the other hand, as shown in fig. 2, 4 and 5, the elbow strut 2 includes a strut body 6 arranged in an upright posture with a lower end portion fixed to the seat S, and a sleeve member 7 detachably fitted to the outside of the strut body 6.

The pillar body 6 is a tubular member having a substantially square shape in plan view, and has an inwardly projecting attachment portion 61 integrally provided at a lower end portion thereof, and the attachment portion 61 is screwed to a lower surface of the seat S in the vicinity of both left and right ends thereof. The sleeve member 7 is a tubular member having a shape similar to the planar shape of the column main body 6, and has a bearing portion 71 having a substantially elliptical shape in plan view integrally formed at an upper end portion thereof, and an inner peripheral surface of the sleeve member 7 is slidably fitted to an outer peripheral surface of the column main body 6. Screw portions 711 (see fig. 2) having screw holes formed in the inner surface thereof are provided near both side edges of the receiving portion 71.

Further, a height adjusting mechanism for adjusting the mounting height position of the cover member 7 with respect to the column main body 6 is configured between the column main body 6 and the cover member 7.

The height adjustment mechanism includes an engaged member 8 having a plurality of engaging holes 81a formed along a height direction, an engaging member 9 having engaging claws 91 selectively engageable in the engaging holes 81a, and a spring 10 (see fig. 4) serving as a biasing means for biasing the engaging member 9 in a direction in which the engaging claws 91 are engageable in the engaging holes 81 a.

The engaged member 8 is a member attached to the inner periphery of the column main body 6, and in the present embodiment, is constituted by a pair of engaged elements 81 and 82 that can be attached to the inner periphery of the column main body 6 so as to embrace a holding member M, which will be described later, from the front to the rear, and the engaging hole 81a is intermittently formed in the engaged element 81 located on the rear side among the engaged elements 81 and 82. Each of the engagement holes 81a is tapered so as to gradually widen toward the inner opening edge. The pair of mating elements are fixed by an appropriate device in a state where the upper and lower end portions of the mating elements are fitted to each other.

The engaging member 9 is a member having a substantially arm-shaped side view in which a fitting portion M1 that can be fitted to the receiving portion 71 of the cover member 7 is provided at an upper end portion, and is configured to be rotatable via a horizontal axis n provided at a predetermined height position. An engaging claw 91 having a tapered shape with a narrow tip end corresponding to the shape of the engaging hole 81a is formed at the lower end portion of the engaging member 9 so as to be engaged with the engaging hole 81a, and the engaging claw 91 is positioned below the lower end of the holding member M. Further, a spring seat portion 92 capable of accommodating the spring 10 is provided at a position higher than the horizontal axis n on the rear edge side of the engaging member 9, and the spring 10 is interposed between the engaging member 9 and the inner surface of the holding member M by the spring seat portion 92, whereby the engaging member 9 is pressed by the spring 10 in a direction in which the engaging claw 91 can be engaged in the engaging hole 81 a. The elbow strut 2 is provided with an operation portion O for operating the engagement member 9. The operation section O has a base end O2 attached to the upper end of the engaging member 9, an operation section main body O1 protruding forward through an opening window 72 formed on the front edge side of the cover member 7, when the user operates the operating portion O in a direction of pushing the operating portion O backward by applying a finger to the operating portion O while holding the cover member 7 from a state in which the engagement claw 91 is engaged with the engagement hole 81a and the vertical movement of the cover member 7 is prohibited, the engaging member 9 is thereby turned about the horizontal axis n, and the engaging state of the engaging claw 91 and the engaging hole 81a is released (as shown by the imaginary line in the figure), allowing the vertical sliding motion of the cover member 7 with respect to the column body 6, at a desired height position, by stopping the operation force to the operation portion O, the engagement claw 91 is engaged in the engagement hole 81a located at the height position.

As shown in fig. 2 and 5, the fitting portion M1 provided at the upper end of the holding member M is a solid portion that is slightly smaller than and similar to the planar shape of the receiving portion 71 of the cover member 7. A fitting recess M11 having a substantially regular octagonal shape in plan view into which a fitting projection 33 of a stationary member 3 described later can be fitted is formed substantially in the center of the fitting portion M1, and a screw hole M12 communicating with the lower side is formed in the center of the fitting recess M11. Further, notches M13 are formed in advance in the vicinity of both side end portions of the holding member M, and the screw portion 711 of the receiving portion 71 is exposed through the notch M13 when the holding member M is inserted from above the cover member 7 and the fitting portion M1 of the holding member M is fitted to the receiving portion 71 of the cover member 7. Further, on the upper surface of the fitting portion M1, a spacer R having a planar shape substantially the same as the planar shape of the fitting portion M1 is disposed so that circular holes R1 formed near both side end portions of the spacer R coincide with the threaded portion 711 of the bearing portion 71, and the bolt B1 inserted into each circular hole R1 from above is inserted into the threaded hole of the threaded portion 711, thereby inhibiting the upward removal of the holding member M. A through hole Ra having substantially the same diameter as the through hole 53a formed in the 1 st receiving portion 53 of the base portion 5 of the elbow rest 1 is formed substantially in the center of the pad R.

Before the elbow rests 1 and the elbow struts 2 having such a configuration are attached, the stationary member 3 and the movable member 4 constituting the stopping mechanism are disposed in the 1 st receiving portion 53 and the 2 nd receiving portion 54 of the elbow rests 1, respectively.

As shown in fig. 2, 5, 6, and the like, the stationary member 3 has a tapered hole 31a formed in the central portion thereof, and includes a main body 31 having an outer peripheral surface 31b set to a diameter slightly smaller than the diameter of the inner peripheral surface of the arc wall 531, a protruding portion 31c protruding outward is provided on a part of the outer peripheral surface 31b of the main body 31, and a plurality of pause engagement recesses 31k recessed inward as pause engagement elements of the present invention are formed on a part of the other region of the outer peripheral surface 31 b. The projection 31c has a substantially fan shape in plan view. In the present embodiment, a total of 4 stop engagement recesses 31k are formed at a predetermined pitch, and an angle of a line segment connecting the center points of the stop engagement recesses 31k located at both ends and the center point of the main body 31 is set to be substantially 90 degrees. That is, a total of 4 dwell-fitting recesses 31k are continuously formed in the region of the center angle of substantially 90 degrees. Further, the center point of the portion where the plurality of stop engagement recesses 31k are formed and the center point of the protrusion 31c are provided at positions opposing each other with the center point of the body portion 31 (the portion where the tapered hole 31a is formed) therebetween. The projection 31c is formed to have a projection dimension substantially corresponding to a recess dimension of the recess 532 formed in the 1 st receiving portion 53. The diameter of the outer peripheral surface 31b of the main body 31, in which the protrusion 31c and the stopper fitting recess 31k are not formed, is set to be slightly smaller than the diameter of the inner peripheral surface of the circular wall 531, which is continuous with the peripheral wall 52 at both side ends, and the outer peripheral surface 31b of the main body 31 is positioned in the vicinity of the side edge portion of the base 5, so that the stationary member 3 is set to be maximally large. The lower surface of the main body 31 integrally includes an insertion portion 32 which is insertable into the through hole 53a of the 1 st receiving portion 53 and the through hole Ra of the pad R, and a fitting convex portion 33 (see fig. 5) which is substantially octagonal in plan view and is fittable into the fitting concave portion M11 of the pad R. A continuous opening hole 34 that opens downward and communicates with the tapered hole 31a is formed in substantially the center of the insertion portion 32 and the fitting convex portion 33.

As shown in fig. 2 and 6, the movable member 4 includes a solid block-shaped movable member body 41 having an engaging piece 41k that is engageable with the pause engaging recess 31k and is integrally provided at one end thereof, and a spring 42 serving as an elastic biasing means for biasing the movable member body 41 forward. The fitting member 41k is convex so that its planar shape corresponds to that of the stop fitting recess 31 k. In addition, a side protruding portion 411 protruding laterally is provided at a lower end portion of the side surface portion of the movable member body 41.

Next, a procedure of housing the stationary member 3 and the movable member 4 in the base portion 5 of the toggle rest 1 will be described. First, the spring 42 of the movable member 4 is disposed in the housing space 54S of the 2 nd housing part 54 so that the expansion and contraction direction thereof coincides with the longitudinal direction of the base part 5, and the movable member body 41 is slid from the housing space 53S of the 1 st housing part 53 to the housing space 54S of the 2 nd housing part 54. At this time, the side protruding portion 411 of the movable member body 41 is slidably moved while being positioned between the bottom surface portion 51 of the base portion 5 and the horizontal piece 541a provided on the opposing wall 541 of the 2 nd accommodating portion 54, and the accommodating operation can be smoothly performed. In this way, the horizontal piece 541a provided in the opposing wall 541 of the 2 nd accommodating portion 54 functions as a guide portion for guiding the sliding movement of the movable member main body 41. As a result, the spring 42 is interposed between the movable member body 41 and the connecting wall 542 of the 2 nd housing portion 54, and the horizontal piece 541a is positioned above the lateral protruding portion 411 provided in the movable member body 41, thereby prohibiting the movable member body 41 from being pulled out upward. Next, the stationary member 3 is accommodated in the 1 st accommodating portion 53 such that the protrusion 31c provided on the body portion 31 of the stationary member 3 is located in the groove 532 of the 1 st accommodating portion 53, and the stop engagement recess 31k formed on the body portion 31 of the stationary member 3 is engaged with the engagement piece 41k provided on the movable member body 41. With this storing operation, the insertion portion 32 of the stationary member 3 is inserted into the through hole 53a of the base portion 5 and the through hole Ra of the spacer R, and the fitting convex portion 33 of the stationary member 3 is fitted into the fitting concave portion M11 formed at the upper end portion of the elbow strut 2. Therefore, in the present embodiment, the fitting convex portion 33 of the stationary member 3 and the fitting concave portion M11 of the elbow strut 2 have planar shapes corresponding to each other, and the fitting concave portion M11 and the fitting convex portion 33 are set to be fitted in any one mounting direction selected from a plurality of mounting directions of the stationary member 3 to the elbow strut 2. The armrest E of the present embodiment in which the stationary member 3 is attached to the elbow strut 2 by the fitting mechanism including the fitting concave portion M11 and the fitting convex portion 33 is configured such that the attaching direction of the stationary member 3 to the elbow strut 2 is different between the armrest E (l) for the left elbow and the armrest E (l) for the right elbow (see fig. 1).

First, the armrest e (l) for the left elbow will be described with reference to fig. 6 and 7. In the case of the armrest e (l) for the left elbow, the mounting direction of the stationary member 3 is determined with respect to the elbow rest 1 positioned at the normal use position LP (fig. 6(a)) in which the longitudinal direction of the elbow rest 1 substantially coincides with the front-rear direction of the chair C, so that the protrusion 31C provided on the main body portion 31 of the stationary member 3 can come into contact with or come close to the right end 532b among the two end portions 532a, 532b of the recessed groove 532 formed in the 1 st receiving portion 53 of the base portion 5, and the fitting convex portion 33 of the stationary member 3 is fitted into the fitting concave portion M11 of the elbow strut 2 while maintaining the mounting direction. In this fitted state, the planar shapes of the fitting convex portion 33 and the fitting concave portion M11 are octagonal shapes corresponding to each other, and therefore the stationary member 3 and the elbow strut 2 are relatively non-rotatable. The planar shapes of the fitting concave portion M11 and the fitting convex portion 33 may be other shapes as long as the shapes can prohibit relative rotation and can obtain a plurality of fitting directions, and in the present embodiment in which the rotation angle of the elbow rest is set to substantially 90 degrees as described later, the quadrilateral shape may be adopted as another shape. In this way, the stationary member 3 is accommodated in the 1 st accommodating portion 53 with the mounting direction of the stationary member 3 to the elbow strut 2 maintained, the bolt B2 is inserted from above the tapered hole 31a formed in the stationary member 3, the bolt B2 is inserted into the continuous opening hole 34 formed in the substantially central portion of the insertion portion 32 and the fitting convex portion 33 of the stationary member 3, and is screwed into the screw portion M12 provided in the fitting concave portion M11, whereby the stationary member 3 is fixed to the elbow strut 2 via the base portion 5. Finally, the upper surface of the base part 5 is covered with an elbow rest cover, a bolt, not shown, is inserted from below each hole edge part 511 provided in the base part 5, and the bolt is screwed into a screw hole, not shown, provided in the elbow rest cover, thereby fastening the base part 5 and the cover member 7 integrally.

Through the above steps, the stationary member 3 is fixed to the elbow strut 2, and the movable member 4 is attached to the elbow rest 1, thereby constituting the armrest e (l) for the left elbow in which the movable member 4 rotates together with the elbow rest 1 with respect to the elbow strut 2. In this state, the spring 42 of the movable member 4 is urged in a direction of pressing the fitting piece 41k formed on the movable member body 41 toward the pivot point P of the toggle rest 1 and the toggle link 2, and the fitting piece 41k is fitted in the rest fitting recess 31k of the stationary member 3.

The armrest e (l) for the left elbow is set to be horizontally rotatable between a normal use position LP (fig. 6(a)) at which the longitudinal direction of the elbow rest 1 substantially coincides with the front-rear direction of the chair C, and a rotation use position LQ (fig. b)) at which the armrest 1 is rotated clockwise by substantially 90 degrees from the normal use position LP about the pivot point of the elbow rest 1 and the elbow strut 2, and the longitudinal direction of the elbow rest 1 substantially coincides with the left-right direction of the chair C. When the elbow rest 1 is rotated between the normal use position LP and the rotational use position LQ, the spring 42 extends when the engaging piece 41k is fitted into the pause engagement recess 31k, and compresses when the engaging piece 41k passes over the outer peripheral surface 31b of the stationary member 3 located between the pause engagement recesses 31k (apparently, like a peak located between the pause engagement recesses 31 k), thereby causing the movable member 4 to move in a straight line along the longitudinal direction of the elbow rest 1. By the action of the spring 42, when the engaging elements 41k are sequentially engaged while being in contact with the 4 stop engaging recesses 31k, that is, when the angle of the toggle rest 1 with respect to the toggle link 2 is changed, the toggle rest 1 is stopped at a predetermined angle to obtain a resistance having an appropriate vibration feeling, and the engaged state is stabilized. When the elbow rest 1 is rotated from the normal use position LP to the rotated use position LQ, the left end 532a of the concave groove 532 formed in the 1 st receiving portion 53 of the base portion 5 of the elbow rest 1, that is, the other end 532a different from the one end 531b of the concave groove 532 which is brought into contact with or close to the protrusion 31c of the stationary member 3 at the normal use position LP comes into contact with the protrusion 31c of the stationary member 3, and the rotation operation of the elbow rest 1 in the clockwise direction beyond the angle is regulated. When the elbow rest 1 located at the rotational use position LQ is rotated counterclockwise and returned to the normal use position LP, the right end 532b of the concave groove 532 comes into contact with the projection 31c of the stationary member 3, and further counterclockwise rotational operation of the elbow rest 1 is prohibited. In this way, the both end portions 532a and 532b of the notch 532 function as contact portions constituting the rotation regulation mechanism of the present invention, and the both end portions 532a and 532b of the notch 532 and the protrusion 31c of the stationary member 3 constitute the rotation regulation mechanism of the present invention. In the present embodiment, the angle formed by the end portions 532a and 532b of the coupling concave groove 532 and the line segment pivoting the point P, that is, the center angle of the concave groove 532 is set to be equal to the sum of the angle formed by the end portions of the coupling protrusion 31c and the line segment pivoting the point P and the rotation angle (substantially 90 degrees) of the toggle rest.

On the other hand, in the case of the armrest e (r) for the right elbow, as shown in fig. 8 and 9, the mounting direction of the stationary member 3 is determined with respect to the elbow rest 1 positioned at the normal use position RP (fig. 8(a)), so that the protrusion 31c of the stationary member 3 can come into contact with or come close to the left end 532a of the both ends 532a, 532b of the recessed groove 532 of the elbow rest 1, and the fitting convex portion 33 of the stationary member 3 is fitted into the fitting concave portion M11 of the elbow strut 2 while maintaining the mounting direction. The subsequent steps of attachment are the same as those of the armrest for the left elbow e (l), and therefore, the description thereof is omitted. In this way, the armrest e (r) for the right elbow is set to be horizontally rotatable between a normal use position RP (fig. (a)) at which the longitudinal direction of the elbow rest 1 substantially coincides with the front-rear direction of the chair C, and a rotation use position RQ (fig. (b)) at which the armrest is rotated counterclockwise by substantially 90 degrees from the normal use position RP about the pivot point P between the elbow rest 1 and the elbow strut 2, and the longitudinal direction of the elbow rest 1 substantially coincides with the left-right direction of the chair C. Further, when the elbow rest 1 is rotated between the normal use position RP and the rotational use position RQ, the spring 42 is expanded when the engaging piece 41k is fitted into the pause engagement recess 31k, and is compressed when the engaging piece 41k passes over the outer peripheral surface 31b of the stationary member 3 positioned between the pause engagement recesses 31k (apparently, a peak positioned between the pause engagement recesses 31 k), whereby the movable member 4 is moved in a straight line along the longitudinal direction of the elbow rest 1, which is similar to the armrest e (l) for the left elbow, and the elbow rest 1 can be stopped at a predetermined angle, and a resistance having an appropriate vibration feeling can be obtained. However, when the elbow rest 1 is rotated from the normal use position RP to the rotation use position RQ, the end 532b on the right side of the concave groove 532 formed in the 1 st receiving portion 53 in the base portion 5 of the elbow rest 1, that is, the other end 532b different from the one end 532a of the concave groove 532 with which or close to the projection 31c of the stationary member 3 comes into contact at the normal use position RP comes into contact with the projection 31c of the stationary member 3, and the further counterclockwise rotation operation of the elbow rest 1 with respect to the elbow strut 2 is regulated. When the toggle rest 1 located at the rotational use position RQ is rotated clockwise to return to the normal use position RP, the left end 532a of the concave groove 532 is brought into contact with the projection 31c of the stationary member 3, and further rotational operation of the toggle rest 1 is prohibited.

In this way, the armrests e (l), e (r) provided in pairs at the left and right ends of the seat S in a bilaterally symmetrical manner are set so as to be able to be adapted to the use state of the seated person, and the elbow rests 1 can be horizontally rotated between the normal use positions LP, RP and the rotational use positions LQ, RQ, and by rotating the elbow rests 1 in the directions of approaching each other, the longitudinal direction of each elbow rest 1 is positioned in a virtual straight line that substantially coincides with the left and right direction of the chair C, and can be used as, for example, a boom or the like when operating a keyboard on a desk. The armrest E is set so that the seated person can freely adjust the height of the elbow rest 1 by the height adjustment mechanism provided in the elbow strut 2.

In this way, in the armrest E of the present embodiment, the stop mechanism includes the stationary member 3 having the plurality of stop engagement recesses 31k on the outer peripheral surface 31b, and the movable member 4 that rotates together with the elbow rest 1 and has the engagement pieces 41k that are sequentially and elastically engageable with the plurality of stop engagement recesses 31k, and the movable member 4 is attached to the elbow rest 1 side while the stationary member 3 is attached to the elbow strut 2 side, so that the engagement direction of the engagement pieces 41k and the stop engagement recesses 31k of the stationary member 3 is always constant regardless of the rotation angle of the elbow rest 1, the engagement relation between the engagement pieces 41k and the stop engagement recesses 31k is always satisfactory regardless of the rotation angle of the elbow rest 1, and the rotation range of the elbow rest 1 can be freely set. Further, since the outer peripheral surface 31b of the main body portion 31 of the stationary member 3 which is brought into contact with or close to the fitting piece 41k can be positioned in the vicinity of the peripheral edge portion 52 of the elbow rest 1, the stationary member 3 can be set to be as large as possible, and the stability of the pivotally supported state of the elbow strut 2 and the elbow rest 1 can be improved.

In particular, since the movable member 4 includes the movable member body 41 provided with the above-described engaging piece 41k and the spring 42 for pressing the engaging piece 41k toward the pivot point P side of the toggle rest 1 and the toggle link 2, the pressing direction of the spring 42 can be always made to coincide with the engaging direction of the engaging piece 41k and the pause engaging recess 31k formed in the stationary member 3 regardless of the rotation angle of the toggle rest 1, and as a result, the pressing function of the spring 42 can be always made effective without being controlled by the rotation angle of the toggle rest 1.

Further, since the rotation regulating means for regulating the rotation angle of the elbow rest 1 with respect to the elbow strut 2 within a predetermined angle is provided, the rotation operation of the elbow rest 1 can be set within a predetermined angle in accordance with the demand of the sitting person, and the utility model is a product with good practicability.

Further, since the rotation regulation mechanism is constituted by the projecting portion 31c provided on the outer peripheral surface 31b of the stationary member 3 and the both end portions 532a and 532b of the recessed groove 532 formed on the inner peripheral surface of the arc wall 531 constituting the 1 st receiving portion 53 which receives the stationary member 3, and the projecting portion 31c is configured to come into contact with the one end portion 532a (or 532b) of the recessed groove 532 when the elbow rest 1 is rotated by a predetermined angle, the further rotation operation of the armrest E can be reliably regulated by the contact of the projecting portion 31c with the one end portion 532a (or 532b) of the recessed groove 532. Further, since the stationary member 3 is accommodated in the 1 st accommodating portion 53, the stationary member 3 can be easily positioned with respect to the elbow rest 1, and since the rotation regulating mechanism is constituted by the 1 st accommodating portion 53 and the stationary member 3 in close contact, the function of regulating the rotation angle of the elbow rest 1 can be effectively improved. Further, since the distance between the both end portions 532a and 532b of the notch 532, that is, the center angle of the notch 532 directly reflects the rotation angle range of the elbow rest 1, the rotation angle range of the elbow rest 1 can be easily set to a desired angle range by appropriately setting the center angle of the notch 532. Further, since the planar shape of the projection 31c is substantially fan-shaped, it is possible to effectively avoid the possibility that the projection 31c itself is damaged due to the projection 31c coming into contact with the end 532a or 532b of the concave groove 532 in accordance with the rotation operation of the elbow rest 1 with a simple configuration.

Further, since the rotation regulation range of the elbow rests 1 can be changed by changing the mounting direction of the stationary member 3 to the elbow strut 2, and the rotation direction of the elbow rests 1 to the elbow strut 2 can be changed, the rotation direction of the armrests E (l), E (r) and the rotation direction from the normal use positions LP and RP to the rotation use positions LQ and RQ in the above embodiment can be changed by a simple operation of changing the mounting direction of the stationary member 3, and the same parts can be used for both the right and left elbow armrests E as compared with the armrests requiring dedicated members for the right and left elbow rests, respectively, thereby contributing to reduction in the number of parts and cost.

In this case, the fitting mechanism is constituted by the fitting convex portion 33 provided at the lower end portion of the stationary member 3 and the fitting concave portion M11 formed at the upper end portion of the elbow strut 2, and these fitting concave portion M11 and the fitting convex portion 33 are fitted in any one of the plurality of mounting directions of the stationary member 3 with respect to the elbow strut 2, and the planar shapes of the fitting convex portion 33 and the fitting concave portion M11 are regular octagonal shapes that substantially correspond to each other, so that the fitting convex portion 33 and the fitting concave portion M11 can be reliably fitted in a tight state in any one of the mounting directions, the fitting state can be maintained well, the fitting convex portion 33 and the fitting concave portion M11 can be prevented from rotating relatively, and the mounting direction deviation of the stationary member 3 with respect to the elbow strut 2 can be reliably prevented. In particular, since the planar shapes of the fitting convex portion 33 and the fitting concave portion M11 are regular octagonal, the armrest can be suitably used as the armrests e (l) and e (r) for the left and right elbows while the rotation angle of the elbow rest 1 is maintained at substantially 90 degrees, and is a product with good practicability. When the rotation angle of the elbow rest 1 is set to approximately 90 degrees, the same effects as described above can be obtained even when the planar shapes of the fitting convex portion 33 and the fitting concave portion M11 are set to be square.

The elbow strut 2 includes a strut body 6 having a lower end portion fixed to the seat S and arranged in an upright posture, and a cover member 7 detachably fitted to the outside of the strut body 6, and a height adjusting mechanism for adjusting a mounting height position of the cover member 7 with respect to the strut body 6 is provided between the strut body 6 and the cover member 7.

In particular, the height adjusting mechanism is provided with the engaged member 8 having a plurality of engaging holes 81a formed along the height direction, the engaging member 9 having the engaging claws 91 selectively engageable in the engaging holes 81a, and the spring 10 serving as a biasing means for biasing the engaging member 9 in the direction in which the engaging claws 91 are engageable in the engaging holes 81a, and is configured to be able to release the engagement state of the engaging claws 91 and the engaging holes 81a by applying a predetermined operating force against the biasing force of the spring 10, so that the height adjusting mechanism is simple in configuration and easy and suitable in operation.

The present invention is not limited to the embodiments described in detail above.

For example, instead of the stop engagement recess having a concave shape, a stop engagement projection having a convex shape may be used as a stop engagement requirement formed on the stationary member. In this case, the shape of the mating member may be concave in accordance with the shape of the stop mating protrusion.

In the above embodiment, the movable member is constituted by the movable member body having the engaging piece and the spring as the elastic urging means, but the movable member may be constituted by a single material which can be elastically deformed such as rubber, and the engaging piece may be engaged with the stop engaging piece by the elasticity of the movable member itself. In addition, for example, a type in which a movable member such as a ball itself functions as an engagement member may be used as the movable member. In the above embodiment, the coil spring is exemplified as the spring serving as the elastic biasing means, but a plate spring or the like may be used.

The rotation regulation mechanism is not limited to the above embodiment, and for example, a protrusion may be provided on an inner peripheral surface of a housing portion that houses the stationary member, and a contact portion may be provided on an outer peripheral surface of the stationary member. In this case, if the recessed groove is formed on the outer peripheral surface of the stationary member, both end portions of the recessed groove can function as the contact portions. In addition, when the rotation angle of the elbow rest with respect to the elbow strut is set to an arbitrary angle, the center angle of the concave groove may be set to the arbitrary angle. Further, the rotation regulation mechanism may not be provided, and the elbow rest may be set to be horizontally rotatable by 360 degrees with respect to the elbow strut. In this case, the stop fitting requirement may be formed continuously or intermittently over the entire outer peripheral surface of the stationary member.

Even when the fitting concave portion constituting the fitting means is provided at the lower end portion of the stationary member and the fitting convex portion is provided at the upper end portion of the elbow strut, the same operational effects as described above can be obtained. The planar shapes of the fitting concave portion and the fitting convex portion are preferably regular polygonal shapes corresponding to each other, but may be irregular shapes such as a rhombus shape and an oval shape as long as at least 2 kinds of fitting combinations are possible. In this case, it is preferable that the planar shapes of the fitting concave portion and the fitting convex portion are set to be at least a shape capable of selecting one fitting state in which the fitting concave portion and the fitting convex portion are fitted in one mounting direction and another fitting state in which the fitting concave portion and the fitting convex portion are fitted in another mounting direction.

As shown in fig. 10, the elbow strut X2 may be configured such that the elbow strut X2 includes a strut body X6 arranged in an upright posture with a lower end fixed to a seat, and a sleeve member X7 fitted to the outside of the strut body X6 so as to be insertable and detachable; a plurality of engagement holes X61 are formed in the height direction at the upper end portion of the column main body X6, and an engagement member X9 having an arm shape in side view is provided, and the engagement member X9 has an engagement claw X91 engageable in the engagement hole X61 at the lower end portion, is set to be rotatable by a horizontal shaft Xn held in the shaft holding portion X71, and is configured to press the engagement claw X91 in the direction of engaging in the engagement hole X61 by the elasticity of a spring X10 held in a spring holding portion X72 provided on the inner peripheral surface of the cover member X7. Further, a height adjusting mechanism may be adopted in which an operation portion XO for operating the engaging member X9 is provided on the elbow strut X2 in a state in which the operation portion XO1 is exposed through an opening window X73 formed on the leading edge side of the sleeve member X7, a base end portion XO2 of the operation portion XO is attached to an upper end portion of the engaging member X9, and the engaging member X9 is rotated about the horizontal axis Xn as a fulcrum by an operation of applying a finger to the operation portion XO to rotate the operation portion XO in an upward direction in a state in which vertical movement of the sleeve member X7 is inhibited from being engaged in the engaging hole X61 from the engaging pawl X91, and accordingly, the engaging state (indicated by a phantom line in the figure) of the engaging pawl X91 and the engaging hole X61 is released, vertical sliding movement of the sleeve member X7 with respect to the strut body X6 is allowed, and at a desired height position, by stopping the operation force to the operation portion, the engagement claw 91 is engaged in the engagement hole 81a located at the height position. In such a product, the number of parts can be reduced as compared with the above embodiment.

In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications may be made without departing from the spirit of the present invention.

Industrial applicability

As described above, in the armrest according to the present invention, the stationary member having the plurality of stop engagement elements formed on the outer peripheral surface thereof is attached to the elbow strut side, and the movable member having the engaging elements which can be sequentially elastically engaged with the plurality of stop engagement elements is attached to the elbow rest side, so that the direction of the elastic engagement between the engaging elements and the stop engagement elements of the stationary member is always constant regardless of the angle of rotation of the elbow rest with respect to the elbow strut, the engagement state between the engaging elements and the stop engagement elements can be always maintained well without being controlled by the angle of rotation of the elbow rest, and the rotation range of the elbow rest can be set at the free end.

Claims (17)

1. An armrest comprising an elbow rest for resting an elbow of a seated person and an elbow support pivotally supporting the elbow rest, wherein the elbow rest is configured to be horizontally rotatable about a pivot point of the elbow rest and the elbow support, and wherein a stopping mechanism for stopping the elbow rest at a predetermined angle is provided between the elbow rest and the elbow support, wherein the stopping mechanism comprises a stationary member having a plurality of stopping engagement elements on an outer circumferential surface thereof, and a movable member which is rotationally movable together with the armrest and has engagement elements which are sequentially elastically engageable with the plurality of stopping engagement elements, wherein the stationary member is attached to the elbow support side, and the movable member is attached to the elbow rest side.

2. The armrest as claimed in claim 1, wherein said movable member is provided with said engaging member and a spring-loading means for urging said engaging member toward said pivot point side.

3. The armrest according to claim 1 or 2, wherein a rotation regulation mechanism is provided for regulating a rotation angle of the elbow rest with respect to the elbow strut within a predetermined angle.

4. The armrest according to claim 3, wherein the elbow rest is provided with a receiving portion that can receive the stationary member, and the rotation regulation mechanism includes a protrusion provided on one of an outer peripheral surface of the stationary member and an inner peripheral surface of the receiving portion, and a contact portion provided on the other that contacts the protrusion when the elbow rest rotates by a predetermined angle.

5. The armrest according to claim 4, wherein a recess having a recessed dimension substantially corresponding to a protruding dimension of the protrusion is provided on one of an outer peripheral surface of the stationary member or an inner peripheral surface of the housing member on which the abutment portion is provided, and both end portions of the recess are provided as the abutment portions so that the protrusion and the abutment portion do not interfere with each other during the rotational movement of the armrest within the predetermined angle.

6. The armrest according to claim 5, wherein an angle formed by a line segment connecting each end of the recess and the pivot point is set to be substantially equal to a sum of an angle formed by a line segment connecting each end of the protrusion and the pivot point and a rotation angle of the elbow rest.

7. The armrest according to claim 5 or 6, wherein the planar shape of said projection is a substantially fan shape.

8. A handrail as claimed in claim 3, 4, 5, 6 or 7, wherein the angle of rotation of the handrail is substantially 90 degrees.

9. The armrest according to claim 3, 4, 5, 6, 7, or 8, wherein the rotation regulation range of the elbow rest is changed by changing the attachment direction of the stationary member to the elbow strut, and the rotation direction of the elbow rest to the elbow strut is changed.

10. The armrest according to claim 9, wherein the stationary member is attached to the elbow strut by means of an engagement mechanism, the engagement mechanism includes an engagement recess provided in one of a lower end portion of the stationary member and an upper end portion of the elbow strut, and an engagement projection provided in the other and engaged with the engagement recess, and the engagement recess and the engagement projection are engaged in any one attachment direction selected from a plurality of attachment directions of the stationary member with respect to the elbow strut.

11. The armrest according to claim 10, wherein an angle formed by a line segment along one mounting direction and a line segment along another mounting direction different from the one mounting direction, among the plurality of mounting directions of the stationary member with respect to the elbow strut, is set to be substantially equal to the rotation angle of the elbow rest.

12. The armrest according to claim 11, wherein the planar shape of the fitting concave portion and the fitting convex portion is set to a shape that enables at least one fitting mode in which the fitting concave portion and the fitting convex portion are fitted in the one mounting direction and another fitting mode in which the fitting concave portion and the fitting convex portion are fitted in the other mounting direction to be selected.

13. The armrest according to claim 10, 11 or 12, wherein the planar shapes of the fitting concave portion and the fitting convex portion are regular polygon shapes that substantially correspond to each other.

14. The handrail of claim 13 wherein the regular polygonal shape is a regular quadrilateral or a regular octagon.

15. The armrest according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14, wherein the elbow strut includes a strut body disposed in an upright posture with a lower end portion thereof fixed to the seat, and a cover member detachably fitted to an outer side of the strut body, and a height adjustment mechanism for adjusting a mounting height position of the cover member with respect to the strut body is provided between the strut body and the cover member.

16. The armrest according to claim 15, wherein the height adjusting mechanism includes an engaged member having a plurality of engaging holes formed along a height direction, an engaging member having engaging claws that can be selectively engaged with the engaging holes, and a biasing device that biases the engaging member in a direction in which the engaging claws can be engaged with the engaging holes; and the engaging state of the engaging claw and the engaging hole can be released by a predetermined operating force.

17. A chair, characterized in that armrests as claimed in any one of claims 1 to 16 are provided on both left and right side end portions of a seat in a pair in bilateral symmetry.