JP7579045B2 - Chair arm rest device - Google Patents

Description

This invention relates to a chair armrest device.

Chair armrest devices are broadly divided into fixed types, where the height and position of the armrest is constant, and movable types, where the height and position of the armrest can be changed. Movable armrest devices are generally constructed so that the armrest is attached to a height-adjustable arm support so that it can be rotated horizontally, etc.

In response to this, Patent Document 1 discloses a configuration that includes a first base body that is fixed to the chair body, a second base body that is attached to the first base body so as to be freely rotatable horizontally, a parallel link mechanism whose rear end is connected to the second base body so as to be able to rotate vertically in the front-to-rear direction, and an armrest that is connected to the front end of the parallel link mechanism so as to be able to rotate horizontally.

In this patent document, the parallel link mechanism can rotate freely up and down and horizontally, so the armrest can be moved laterally in and out of the seat when viewed from above, while the height can be adjusted. Therefore, the range of motion of the armrest is significantly wider than that of the armrest support system.

Furthermore, in Patent Document 1, the parallel link mechanism consists of a main link as a strength member and an auxiliary link for holding the elbow rest in a horizontal position, and the main link is formed with a C-shaped cross section that opens downwards, and the auxiliary link and a mechanical member for adjusting the height are arranged inside the main link.

Special table 2015-529144 publication

As mentioned above, the armrest device of Patent Document 1 has a large range of movement for the elbow rest, making it highly adaptable to different user preferences and physiques. However, because the auxiliary link and mechanical components are located within the space between the upper and lower openings of the main link, the installation and removal of the auxiliary link and mechanical components is cumbersome, resulting in poor workability during assembly and maintenance. In addition, because the main link is covered by upper and lower covers, the number of components increases, which may increase costs.

In addition, in Patent Document 1, a combination of a fixed gear and a movable gear that engages and disengages from the fixed gear is used as a means for maintaining the posture of the main link, and the main link can be rotated up and down by operating a lever to disengage the movable gear from the fixed gear. However, in Patent Document 1, the fixed gear is formed on the second base body that rotates horizontally, and therefore the second base body must be manufactured from a hard material to prevent chipping of the gear teeth, which may increase costs and weight.

The present invention was made in response to this current situation, and aims to provide an armrest device with a main link that can rotate freely horizontally and up and down, similar to that of Patent Document 1, in an improved form.

The present invention is an armrest device to be attached to a chair body, and the armrest device comprises, as described in claim 1,
"The chair has a base body fixed to the chair body, a front support body attached to the base body via a parallel link mechanism so as to be movable up and down, an armrest attached to the front support body, and a mechanism member for switching the parallel link mechanism between a rotatable state and a non-rotatable state ,
The parallel link mechanism is composed of a main link in the longitudinal direction as a strength member, and an auxiliary link for maintaining the horizontal position of the elbow pad, and both of the links are connected to the base body and the front support body so as to be relatively rotatable.
In this configuration,
"The main link has a vertical base plate that constitutes the exterior of the seat side , a horizontal portion that protrudes outward in the left and right direction from the base plate, and has a cross-sectional shape with a roughly L-shaped portion that opens outward in the left and right direction. A cover is attached to the main link from the outside, and the auxiliary link and mechanical members are arranged in the space between the main link and the cover."
The structure is as follows.

The present invention can be developed in various ways. For example, in claim 2,
"The base body is composed of a first base body fixed to the chair body and a second base body attached to the first base body so as to be freely rotatable horizontally, and the main link and auxiliary link are connected to the second base body."
The structure is as follows.

The invention of claim 3 is the same as claim 1 or 2,
"The L-shaped portion of the main link is configured so that a top plate is integrally formed as the horizontal portion at the upper end of the base plate."
The structure is as follows.

Furthermore, in claim 4, in claim 2 ,
"A horizontal support shaft is provided on the second base body so as to protrude outward in the left-right direction, and the base plate of the main link is rotatably connected to the support shaft, and a fixed gear is non-rotatably attached to the outside of the base plate of the main link,
A movable gear that is engaged with and disengaged from the fixed gear by lever operation is rotatably connected to the base plate of the main link.
The structure is as follows.

In the present invention, the space surrounded by the main link and cover in which the auxiliary link and mechanical members are arranged is open to the outside in the left and right direction, so that the auxiliary link and mechanical members can be easily attached and detached, which greatly improves the ease of assembly and maintenance of the armrest device.

In addition, with the present invention, the main link can be formed into a hollow structure with just one cover, simplifying the structure. Also, since the main link itself forms the exterior, it can be made thicker, which also contributes to increased strength.

By adopting the configuration of claim 2, the elbow rest can be rotated widely in the left and right directions, expanding the range of motion of the elbow rest and greatly improving usability.

The main link can be formed in an L-shape with a bottom plate at the lower end of the base plate, but if it is formed in an inverted L-shape with a top plate on the base plate as in claim 3, the top surface of the main link is made of a strong top plate, so deformation can be prevented even if an object hits the main link from above.

When the configuration of claim 4 is adopted, since the fixed gear is separate from the second base body, for example, the second base body can be made of aluminum die-cast or resin molded, and the fixed gear can be made of iron. In this way, a material that prioritizes light weight and ease of manufacture can be selected for the second base body, and a material that prioritizes strength can be selected for the fixed gear. This makes it possible to achieve both light weight and strength.

1A is a front perspective view of a chair to which an embodiment is applied, FIG. 1B is a rear perspective view, and FIG. 1C is a rear perspective view of only the back portion. 1A and 1B are diagrams showing an armrest device according to an embodiment, in which FIG. 1A is a plan view of the armrest device, and FIG. 1B is an exploded plan view of the armrest device. FIG. 1A is an exploded perspective view centered on a main link, and FIG. 1B is a plan view showing a state in which a second base body is attached to a first base body. 10A is an exploded perspective view of a main link and a base body, FIG. 10B is a cross-sectional view taken along the line VIB-VIB in FIG. 10B, and FIG. 10C is a partial perspective view of the main link. 1A is a perspective view of a main link and a base body separated from each other, and FIG. 1B is a perspective view of a front end portion of the main link as viewed from the back side. 3A is an exploded perspective view centered on the base body, and FIG. 3B is a cross-sectional view taken along the line VIII-VIII in FIG. 1A is an exploded perspective view of the base body, FIG. 1B is a diagram showing the state of attachment to the back frame, FIG. 1C is a perspective view of the first base body, and FIG. 1D is a plan cross-sectional view showing the state of attachment to the back frame. 1A is a partially separated side view with the cover omitted, and FIG. 1A is an exploded perspective view for explaining an adjustment mechanism, FIG. 1B is also an exploded perspective view for explaining the adjustment mechanism, and FIG. 1C is a perspective view of components as viewed from the front.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following, the terms front, back, left and right are used to specify directions, but these directions are specified as viewed from a normally seated person. The front viewing direction is the direction facing the seated person.

(1) Overview of the Chair First, an overview of a chair to which the armrest device of this embodiment is applied will be described mainly with reference to Figure 1. This chair is a swivel chair that is widely used in offices and the like, and comprises, as its main components, a seat 1, a backrest 2, a back frame 3 to which the backrest 2 is attached, and a leg device 4 with casters. A lumbar support device 5 is disposed behind the backrest 2. The chair also comprises, as optional items, an armrest device 6 of this embodiment and a headrest (or shoulder rest) 7.

The back frame 3 is equipped with a back support 8 located in the left-right middle, left-right long upper supports 9 attached to the top ends of the back support 8, and lower supports 10 extending left and right from the bottom ends of the back support 8. The backrest 2 is connected to both left and right ends of the upper support 9 and both left and right ends of the lower support 10. Therefore, the backrest 2 is connected to the back frame 3 in a four-point support state.

The upper support 9 is manufactured separately from the back support 8, and is attached to the back support 8 by a pivot means (not shown) so that it can rotate horizontally. On the other hand, as shown in FIG. 1(C), the backrest 2 has a back panel (inner shell) 2a and cushioning material 11 stretched on its front and back, and the cushioning material 11 on the front and back is covered with a bag-shaped skin material. The backrest 2 can have various structures, such as a type in which a mesh material is stretched on a back frame that is open at the front and back.

Although not shown in the figures, a forward-facing portion is formed integrally with the lower end of the back frame 3, and as shown in Figure 2, a tilting member 12 fixed to the forward-facing portion is connected to a base 13 fixed in the state of the leg device 4 so as to be able to tilt backward. Therefore, the chair of this embodiment is a rocking chair in which the backrest 2 tilts backward against the spring means, and the armrest device 6 tilts backward together with the backrest 2.

The lower support 10 is curved in a plan view so as to surround the rear of the seat 1. That is, as shown in FIG. 3, it extends in a curved state toward the left and right outside and toward the front. Also, as shown in FIG. 1(B), it is inclined so that its height increases toward the front. Furthermore, as shown in FIG. 3, the width of the lower support 10 decreases toward the tip. That is, the lower support 10 tapers toward the tip in a plan view.

Now, since the armrest device 6 is attached to the lower support 10, the downward load acting on the armrest device 6 acts as an external force that twists the lower support 10. In this case, if the lower support 10 extends straight to the side, a strong twisting force acts on the lower support 10, so the lower support 10 needs to be made larger.

In contrast, in this embodiment, the lower support 10 is curved in plan view and extends outward to the left and right and toward the front, so that a combined bending force and twisting force acts on the lower support 10, providing high resistance. Therefore, the lower support 10 can be made as thin as possible while still ensuring the necessary strength.

1B and 1C, the lower support 10 has a vertical width that narrows toward the tip. Conversely, the vertical width increases toward the back support 8. Therefore, the load acting on the armrest device 6 can be supported accurately.

The back support 8 and upper support 9 are made of synthetic resin, but can also be made of aluminum die-cast or metal plate. A center cover 14 and a side cover 15 are attached to the back of the back support 8 and lower support 10. That is, the center cover 14 covers the entire back support 8 and approximately half of the lower support 10, and the side cover 15 covers approximately half of the tip side of the lower support 10. When attaching the armrest device 6, a side cover 15 with mounting holes is used.

(2) Outline of Armrest Device and Swivel Mechanism Next, the structure of the armrest device 6 will be described with reference to Figure 2 and subsequent drawings. First, an outline will be described.

As can be seen from Figures 4 and 5, the armrest device 6 comprises a first base body 21 fixed to the tip of the lower support 10 on the back frame 3, a second base body 22 mounted on the first base body 21 so as to be freely rotatable horizontally, a main link 23 and an auxiliary link 24 whose rear ends are connected to the second base body 22 in the fore-and-aft direction, a front support body 25 connected to the front ends of the main link 23 and the auxiliary link 24, and an armrest 26 attached to the front support body 25 so as to be freely movable forward and backward and rotatable horizontally.

The front and rear connecting parts of the main link 23 and the auxiliary link 24 are vertically separated. Therefore, the main link 23 and the auxiliary link 24 form a parallel link mechanism. Therefore, when the main link 23 and the auxiliary link 24 rotate up and down with their rear ends as fulcrums, the front support 25 moves up and down while maintaining a vertical position. Therefore, the elbow rest 26 can be adjusted in height while maintaining a horizontal position.

The elbow rest 26 can be adjusted left and right by rotating the main link 23 and auxiliary link 24 horizontally, and the elbow rest rotation mechanism allows the plan view posture and front and rear position to be adjusted.

The elbow rest 26 is long from front to back, and can move in its longitudinal direction and rotate horizontally. The elbow rest rotation mechanism that realizes this movement is shown in Figure 4. This point will be explained next.

The armrest rotation mechanism has a receiving frame 28 that is open upwards in the front-to-back direction and is placed on the front support 25 via a finger-pinch prevention plate 27. The armrest 26 is attached to the receiving frame 28. A circular boss body 29 is provided at the center of the front support 25, and the receiving frame 28 has an elongated hole through which the boss body 29 passes. Therefore, the receiving frame 28 can slide in its longitudinal direction.

A slide auxiliary body 30 that is long in the longitudinal direction of the receiving frame 28 is arranged inside the receiving frame 28, and a cover member 31 is placed on top of the slide auxiliary body 30, and a posture holder 32 with an upper flange is fitted onto the cover member 31 from above. The slide auxiliary body 30 and the cover member 31 are fitted onto the boss body 29 of the front support body 25 so as to be non-slidable and rotatable, and the posture holder 32 is fixed to the boss body 29 by a screw 33 so as not to be rotatable.

The inner surface of the receiving frame 28 is formed with uneven portions 34 for adjusting the front-rear position, while the slide auxiliary body 30 is formed with a locking portion 35 that abuts against the uneven portion 34 and is capable of horizontal rotation, and has a built-in lower rubber 36 that applies resistance to the inward rotation of the locking portion 35. Therefore, the front-rear position of the elbow pad 26 can be adjusted against the elasticity of the lower rubber 36.

The slide auxiliary body 30 opens upward, and abutments 38 supported from the outside by upper rubber 37 are arranged on both sides of the axis, while the outer periphery of the posture holder 32 is formed with uneven parts 39 against which the abutments 38 come into contact. Therefore, the elbow rest 26 can be rotated horizontally against the elasticity of the upper rubber 37.

(3) Structure of the Base Portion Next, the first base body 21 and the second base body 22 will be described mainly with reference to Figures 5 to 9. The first base body 21 and the second base body 22 are aluminum die-cast products, but it is also possible to use resin molded products.

As shown in Figures 7 and 8, the first base body 21 is formed in a cup shape that narrows downward, and an arm portion 43 that extends toward the lower support 10 of the back frame 3 is integrally formed on its upper portion (approximately the upper half), and a flange 44 that protrudes downward from the arm portion 43 is fixed to the lower support 10 with a bolt 45.

In this case, as shown in Figures 6 and 9 (B) and (D), the lower support 10 is provided with an engagement hole 46 that opens outward, while the arm portion 43 is formed with an engagement protrusion 47 that fits snugly into the engagement hole 46. Therefore, the downward load acting on the arm rest 26 is supported by the engagement between the engagement protrusion 47 and the engagement hole 46. For this reason, high support strength can be obtained even when fastened with a single bolt 45.

As shown in FIG. 8B, the first base body 21 has a bearing hole 48 that tapers downward and opens upward, and a boss portion 49 that constitutes the second base body 22 is fitted into the bearing hole 48 via a synthetic resin bushing 50. The first base body 21 also has a straight downward opening hole 51. A retaining ring 52 is disposed in the downward opening hole 51, and the retaining ring 52 is fixed to the boss portion 49 of the second base body 22 by a bolt 53. The retaining ring 52 is formed in a double cylindrical shape with an upward annular groove 54, and a collar 55 is fitted into the upward annular groove 54.

As shown in Figures 8(A) and 9(A), the second base body 22 has a flange 22a that fits into the upper part of the first base body 21 , and a pair of protrusions 56 are formed on the lower surface of the flange 22a, and notches 57 formed in the bushing 50 fit into these protrusions 56. Therefore, the bushing 50 rotates integrally with the second base body 22. As shown in Figure 9(D), a notched groove 57a into which the protrusions 56 fit is also formed inside the first base body 21.

The second base body 22 has a bracket portion 58 exposed on the first base body 21. The bracket portion 58 is formed to be shifted (offset) toward the back frame 3 from the rotation center of the second base body 22, and has a plate-like shape. In addition, as shown in FIG. 7, for example, the bracket portion 58 is provided with a reinforcing rib 58a connected to the boss portion 49.

As shown in FIG. 5(B), the outer surface of the bracket portion 58 opposite the seat 1 is located near the rotation axis O1 of the second base body 22, and a horizontally oriented support shaft 59 for connecting the main link 23 is integrally formed on the outer surface of the bracket portion 58. Therefore, a bearing hole 23a that fits onto the support shaft 59 is provided at the base end (rear end) of the main link 23.

The support shaft 59 is contained within the area of the first base body 21 in plan view. This prevents the downward load acting on the back support 8 from acting as a large moment on the second base body 22 and the first base body 21. As a result, the load support strength of the first base body 21 can be improved.

For example, as shown in FIG. 7, the bracket portion 58 of the second base body 22 is covered by a hood 60 from the side of the lower support 10. A ring portion 60a is formed at the lower end of the hood 60, surrounding the bracket portion 58 from the front, and the outer diameter of the ring portion 60a is the same as the outer diameter of the upper end of the first base body 21. Therefore, the outer surface of the hood 60 and the outer surface of the first base body 21 are aligned so as to be continuous with each other. This results in an excellent aesthetic appearance.

(4) Parallel link mechanism/attitude holding mechanism Next, the structure centered on the main link 23 will be described. For example, as shown in Fig. 5, most of the main link 23, except for the front and rear parts, is an L-shaped part with a top plate 64 integrally formed on the upper end of a vertically oriented base plate 63. Therefore, there is a space that opens to the left and right outside and below, and this space is closed from the outside by an L-shaped cover 65. The rear end of the top plate 64 is a rear plate 64a that is bent downward. As shown in Fig. 7, a recess 66 is formed on the side of the base plate 63 to reduce weight. On the other hand, as shown in Fig. 7, a reinforcing rib 67 is formed on the lower surface of the top plate 64. The top plate 64 is an example of a horizontal part.

The support shaft 59 penetrates the rear end of the main link 23 and is exposed at the front, and the fixed gear 68 is connected to this exposed end so that it cannot rotate. That is, for example, as shown in FIG. 7, the tip of the support shaft 59 is formed into a square portion 59a, while the fixed gear 68 is formed with a square hole 69 that fits snugly into the square portion 59a, thereby holding the fixed gear 68 so that it cannot rotate. The fixed gear 68 is held by a screw (not shown) so that it cannot come off the support shaft 59, and the main link 23 is held by the fixed gear 68 so that it cannot come off the support shaft 59.

The tip of the main link 23 is bifurcated, and a connecting part 71 provided at the bottom of the front support 25 is connected to this bifurcated tip 70 by an upper pin 72 in a horizontal position. In other words, the connecting part 71 of the front support 25 is also bifurcated, but the bifurcated tip 70 of the main link 23 sandwiches the connecting part 71 of the front support 25, and in this state, they are connected by the upper pin 72. The upper pin 72 is held in place by the hood 60 so that it cannot come off.

Furthermore, the connecting portion 71 of the front support 25 and the bracket portion 58 of the second base body 22 are connected by the auxiliary link 24. That is, the front end of the auxiliary link 24 is disposed inside the bifurcated connecting portion 71 of the front support 25 and is connected to the connecting portion 71 by a horizontal lower pin 74 so as to be movable relative to the connecting portion 71, while the rear end of the auxiliary link 24 is connected to a horizontal pin 75 protruding outward from the bracket portion 58 of the second base body 22.

As shown in FIG. 6(C), below the bearing hole 23a in the base of the main link 23 is an elongated hole 23b into which the lateral pin 75 of the bracket part 58 fits. Therefore, the main link 23 can rotate up and down within the range in which the elongated hole 23b moves relative to the lateral pin 75. Therefore, even if the meshing between the gear parts 68a and 76a becomes disengaged for some reason, the elbow rest 26 will not drop excessively. In other words, the elongated hole 23b functions as a safety device.

The fixed gear 68 described above has a fixed gear portion 68a formed on the front surface. A movable gear 76 that rotates around an axis parallel to the rotation axis of the main link 23 is disposed on the front side of the fixed gear 68. For example, as shown in FIG. 5(A), a movable gear portion 76a that engages with and disengages from the gear portion 68a of the fixed gear 68 is formed on the rear of the movable gear 76, and the main link 23 is switched between a rotatable state and an unrotatable state by the rotation of the movable gear 76. The movable gear 76 is connected to a boss 77 (see FIG. 5, for example) protruding from the base plate 63 of the main link 23, and is held in place by a screw (not shown) so that it cannot be removed.

The movable gear 76 is rotated by, for example, an operating lever 78 as shown in FIG. 11. The operating lever 78 has a finger hook exposed at the front of a case 79 that holds the front support 25 from below. The operating lever 78 also has a support pin 78a that protrudes outward to the left and right, and the support pin 78a is fitted into a bearing recess 81 (FIG. 11(C)) provided in the front support 25. Therefore, the operating lever 78 rotates up and down with the support pin 78a as a fulcrum. As shown in FIGS. 11(A) and (B), a notch 79a is formed in the case 79 to expose the finger hook of the operating lever 78.

The rotation of the operating lever 78 is transmitted to the rotation of the movable gear 76 via the intermediate lever 82. The intermediate lever 82 has its front and rear midpoints connected to a boss 83 provided on the base plate 63 of the main link 23, and the downwardly inclined portion 78b of the operating lever 78 abuts its front end from above (the intermediate lever 82 is held rotatably and immovably on the boss 83 by a screw). In addition, a forward arm 76b provided on the movable gear 76 is inserted into a rearward opening tubular portion 82a provided on the main link 23. Furthermore, a spring piece 82b that abuts against the top plate 64 of the main link 23 is formed on the intermediate lever 82.

When the operating lever 78 is not being hooked with a finger, the movable gear 76 is held in mesh with the fixed gear 68 by the spring piece 82b. The angle of the main link 23 is therefore maintained, and the height of the elbow rest 26 is maintained. When the operating lever 78 is hooked with a finger and pulled upward, the main link 23 rotates, and the movable gear 76 disengages from the fixed gear 68, allowing the main link 23 to rotate up and down.

As mentioned above, the cover 65 is L-shaped, and as shown in FIG. 7, it has a horizontal piece 65a at its lower end. The front ends 65b and 65c of the cover 65 overlap the front end of the main link 23, and are covered by the case 79. Therefore, the front end of the cover 65 is held in an inseparable state from the main link 23.

On the other hand, although not shown, the rear end 76d of the cover 65 is engaged with the rear end of the main link 23 by a claw means, not shown. Therefore, an engagement means such as an engagement groove is provided at the rear end of the main link 23. It is also possible to firmly position the cover 65 by forming ribs facing toward the main link 23 on the upper and rear edges of the cover 65, while forming grooves on the outer surface of the main link 23 into which the ribs fit. It is also possible to fix the horizontal piece 65a of the cover 65 to the main link 23 with a screw.

(5) Summary The support shaft 59 to which the main link 23 is connected protrudes from the bracket portion 58 provided on the second base body 22, so that the longitudinal center line O2 of the main link 23 is located outside (opposite the seat 1) the rotation axis O1 of the second base body 22, as shown in Figure 3 (A). Therefore, the first base body 21 can be shifted as far as possible toward the lower support 10 of the back frame 3, making the entire armrest device 6 more compact.

As shown in FIG. 5B, the support shaft 59 is within the range of the first base body 21 in a plan view, so no large bending moment acts on the second base body 22 and the first base body 21. Therefore, even if the longitudinal center line O2 of the main link 23 protrudes outside the horizontal rotation axis O1 of the second base body 22 and the main link 23, the load on the first base body 21 can be reduced.

Furthermore, the load acting on the elbow rest 26 acts on the second base body 22 via the main link 23, but since the base plate 63 of the main link 23 is close to the bracket part 58 of the second base body 22, the point of application of the load can be moved as close as possible to the axial center of the first base body 21 and the second base body 22. This ensures high support strength.

The auxiliary link 24 is disposed in the space between the main link 23 and the cover 65. In addition, the attitude-maintaining members (mechanical members) such as the fixed gear 68, movable gear 76, auxiliary link 24, and intermediate lever 82 are also disposed outside the base plate 63 of the main link 23, making it easy to attach these members. In other words, the outside of the base plate 63 is open as a large space, making it easy to perform tasks such as connecting the auxiliary link 24, setting members such as the fixed gear 68, and screwing in screws. This reduces the effort required to assemble and maintain the armrest device 6.

As mentioned with reference to Figure 7 (A), forming a recess 66 on the inner surface of the main link 23 (the surface facing the seat 1) is advantageous in terms of cost, since it reduces the amount of material used while ensuring the necessary strength. Another advantage is that it prevents distortion.

The main link 23 in this embodiment can basically be said to be inverted L-shape, but considering the recess 66, it can also be specified as being composed of a vertically oriented base plate 63 and horizontal parts provided at its upper and lower ends, with the upper and lower horizontal parts protruding in at least one of the left and right directions. In any case, it has an L-shaped part.

Although the embodiments of the inventions of this application have been described above, the inventions of this application can be embodied in various other ways. For example, the main link 23 can be formed into a U-shape that opens outward, and the opening can be covered with a cover. Also, in the embodiment, the armrest device is attached to the lower support of the back frame, but the armrest device can be attached to other parts of the back frame, a base provided at the upper end of the leg support, or each part that constitutes the chair body, such as the seat outer shell (seat support member).

The present invention can be embodied in a chair armrest device. Therefore, it can be used industrially.

REFERENCE SIGNS LIST 1 seat 2 backrest 3 back frame 6 armrest device 8 back support 10 lower support 21 first base body 22 second base body 23 main link 24 auxiliary link 25 front support 26 armrest 58 bracket portion 59 support shaft 63 main link base plate 64 main link top plate 65 cover 68 fixed gear 76 movable gear 78 operating lever 82 intermediate lever

Claims (4)

An armrest device that is attached to a chair body,
The chair has a base body fixed to the chair body, a front support body attached to the base body via a parallel link mechanism so as to be movable up and down, an armrest attached to the front support body, and a mechanism member for switching the parallel link mechanism between a rotatable state and a non-rotatable state ,
The parallel link mechanism is composed of a main link in the longitudinal direction as a strength member and an auxiliary link for maintaining the horizontal position of the elbow rest, and both links are connected to the base body and the front support body so as to be relatively rotatable,
The main link has a vertical base plate constituting the exterior of the seat side , a horizontal portion protruding outward in the left-right direction from the base plate, and has a cross-sectional shape having a generally L-shaped portion opening outward in the left-right direction. A cover is attached to the main link from the outside, and the auxiliary link and a mechanical member are arranged in the space between the main link and the cover.
Chair arm rest device. The base body is composed of a first base body fixed to the chair body and a second base body mounted on the first base body so as to be horizontally rotatable, and the main link and the auxiliary link are connected to the second base body.
2. A chair armrest device according to claim 1. The L-shaped portion of the main link is configured such that a top plate is integrally formed as the horizontal portion on the upper end of the base plate.
3. A chair armrest device according to claim 1 or 2. A horizontal support shaft is provided on the second base body so as to protrude outward in the left-right direction, a base plate of the main link is rotatably connected to the support shaft, and a fixed gear is non-rotatably attached to the outer side of the base plate of the main link,
A movable gear that is engaged with and disengaged from the fixed gear by a lever operation is rotatably connected to a base plate of the main link.
3. A chair armrest device according to claim 2 .

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