JPH0970332A - Armrest of chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate smoothly an armrest, and prevent an unexpected change in its vertical position by providing a guiding member in both supporting members in a liftable manner, providing a rack in one of the guiding members, providing an interlocking member in the other guiding member, which are operated into a fixing-release position and a fixing position by an operation member, and providing an elastic member in the fixed position. SOLUTION: A guiding member 7 is inserted into a supporting member 8 provided on both sides of a chair, and a rack 9 is provided on both sides of the supporting member 8. An interlocking member 10 which interlocks with the rack 9 is provided in a pair of front and rear guide grooves of the guiding member 7 in a slidable manner. These interlocking members are operated into the fixing position which checks lifting/lowering of an armrest 4 by interlocking and the unfixing position which releases interlocking and permits lifting with the operation member 11. A spring 12 which springs into the fixing position is provided between the guiding member 7 and the interlocking member 10, and the armrest is moved up and down by canceling the interlocking by depressing the operation member 11 against the spring force, and fixed without resting a hand.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a height-adjustable chair armrest.

[0002]

2. Description of the Related Art Conventionally, as an armrest of a chair whose height is adjustable, there is one disclosed in, for example, Japanese Utility Model Publication No. 4-46606. This is because a guide member that is vertically installed on the lower surface of an armrest is vertically fitted into a support member that is erected on both sides of a chair so that a rack is fixed to the support member, and the guide member is the rack. A pinion that rotatably supports the pinion, and a leaf spring that elastically biases the pawl that meshes from the radial direction of the pinion in a direction that meshes the pinion, and the pawl that resists the elastic biasing force of the leaf spring. The guide member is provided with an operation member that is operated to a position where the engagement with the pinion is released.

However, according to the above construction, when the upper and lower positions of the armrests are held, since the claws and the pinions mesh with each other, the meshing range is very narrow and the claws can escape in the radial direction of the pinion. Therefore, when a large force is applied to the armrest, the pawl moves to the side away from the pinion against the elastic biasing force of the leaf spring, and the engagement between the pawl and the pinion is disengaged. Sometimes the top and bottom positions of were changed unexpectedly. It is conceivable to increase the elastic biasing force of the leaf spring so that the engagement between the pawl and the pinion is difficult to disengage, but in this case, the position where the operating member is disengaged from the pinion against the elastic biasing force of the leaf spring. There was room for improvement in terms of operability because it required a large amount of operating force to operate.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention is to solve the problem that the operating member can be operated lightly when adjusting the height of the armrest, This is to prevent the vertical position of the armrest from being changed unexpectedly after the height adjustment is completed.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a guide member which is vertically installed on a lower surface of an armrest is vertically fitted to a support member which is erected on both sides of a chair. A rack having teeth formed in the vertical direction is provided on one of the support member and the guide member, and an engaging member having a smaller number of teeth than the rack engaging with the rack is provided on the other side of the rack. The engagement member is selectively placed in a fixed release position that releases the engagement between the engagement member and the armrest to allow the armrest to move up and down, and a fixed position that engages the engagement member with the rack to prevent the armrest from moving up and down. And an elastic member for elastically urging the engagement member to a fixed position where the engagement member engages with the rack.
When the upper and lower positions of the armrest are held, the teeth of the meshing member mesh with the teeth of the rack at a plurality of positions, so that the meshing range can be made wider than in the conventional case. When the armrest is adjusted up and down, the armrest is moved up and down by operating the operation member against the elastic biasing force of the elastic member to release the engagement between the rack and the engagement member. After the vertical movement of the armrest is completed, by releasing the hand from the operating member, the elastic biasing force of the elastic member moves the meshing member to a position where it meshes with the rack, and holds the armrest at that position.

Of the pair of tooth surfaces extending from the addendum side to the tooth groove side, the rack is formed so that the first tooth surface located on the upper side extends along the horizontal direction orthogonal to the vertical direction, and
The first rack portion having a large number of tooth profiles formed on the inclined surface where the second tooth surface located on the lower side is closer to the tooth groove on the tooth groove side, and the pair of tooth surfaces extending from the tooth tip side to the tooth groove side. Our
The third tooth surface located on the upper side is formed on the inclined surface closer to the tooth groove on the tooth groove side, and the fourth tooth surface located on the lower side is formed in a shape along the horizontal direction orthogonal to the vertical direction. In addition to being composed of a second rack portion having a large number of tooth shapes,
A meshing member that meshes with the rack, a first meshing portion having a first meshing tooth surface along the horizontal direction that meshes with the first tooth surface, and when meshing the first tooth surface and the first meshing tooth surface. And a second meshing portion having a second meshing tooth surface along the horizontal direction that meshes with the fourth tooth surface. First tooth flank and first
By engaging with the meshing tooth surface, the armrest is prevented from moving downward, and at the same time, the fourth tooth surface and the second meshing tooth surface are meshed with each other, and the armrest is prevented from moving upward. However, since the meshing surfaces are in the horizontal direction orthogonal to the vertical direction, the meshing does not come off, and the vertical movement of the armrest can be reliably prevented.
Moreover, at the time of meshing between the first tooth surface and the first meshing tooth surface and at the time of meshing between the fourth tooth surface and the second meshing tooth surface, along the inclined surface of the second tooth surface and the inclined surface of the third tooth surface. The rack and the meshing member can be smoothly moved and guided.

The meshing width between the first tooth surface of the rack and the first meshing tooth surface of the meshing member is made wider than the meshing width of the fourth tooth surface of the rack and the second meshing tooth surface of the meshing member. is there.
Generally, the weight of the arm acts downward on the armrest, and even if a large load is applied to the armrest by widening the meshing width between the first tooth surface and the first meshing tooth surface of the rack. There is no damage in the meshing part, the meshing of the rack and the meshing member is disengaged, the meshing position of the rack and the meshing member is changed, and the vertical position of the armrest is changed unexpectedly, It is possible to reliably prevent the guide member from coming off the support member when the chair is lifted to move the chair.

The engaging member is provided so as to be movable only in a direction parallel to the tooth surface of the rack, and the engaging member is positioned in front of the rack from a position laterally displaced from the rack. The two are configured to mesh with each other. By configuring the teeth of the meshing member to mesh with the teeth of the rack by moving only in a direction parallel to the tooth surface of the rack, a large force acts on the armrest to move the meshing member to the tooth surface of the rack. Even if the force in the separating direction acts on the rack,
Since the meshing member is provided in a state in which the meshing member is prevented from separating in the direction orthogonal to the tooth surface of the rack, the state in which the teeth of the meshing member are reliably meshed with the teeth of the rack is maintained. It is possible. Since the force acting on the armrest does not directly act as a force for moving the meshing member to the position laterally displaced from the rack, the elastic biasing force of the elastic member is transmitted to the rack when the meshing member moves, for example. It is only necessary to prevent movement to a position laterally laterally displaced from the front of the rack due to indirect force other than the force directly acting on the armrest, etc. The elastic biasing force may be set.

Teeth are integrally formed on the front and rear side surfaces of the supporting member to form a rack, and the engaging member is
At the fixed position, the supporting member is provided with abutment surfaces that come into abutment with three surfaces of one of the front and rear side surfaces and the left and right side surfaces of the support member, and the teeth formed on the front and rear side surfaces of the support member. A pair of teeth for simultaneously engaging in a fitted state from a direction parallel to the tooth surface is provided. By forming teeth on the supporting member itself to form a rack, it is not necessary to form the rack with a separate member, and there is no need to attach a separate rack. Moreover, the rack is supported by three abutment surfaces of the engagement member in three directions, and at the same time, the pair of teeth of the engagement member are engaged with the pair of teeth of the rack at the same time. Even if a force in the direction of action is applied, the meshing member can securely support the rack in abutment, so that not only can the rack be prevented from being deformed, but also the rack and the meshing member can be prevented from rattling. As a result, the engagement of both members can be reliably maintained.

The operating member is composed of an operating portion facing a hole formed in the side wall of the guide member, and a rectangular annular body integrally formed on the back surface of the operating portion, and the operating member has a rectangular shape. The meshing member is formed by forming teeth on the inner surface that mesh with the teeth formed on the front and rear side surfaces of the support member. By integrally forming the two members of the operating member and the meshing member, the number of manufacturing steps can be reduced as compared with the case where the two members are configured as separate members, and the assembling for assembling the two members. It is possible to eliminate the work and the linking structure of the two members. Moreover, it becomes possible to dispose the two members in close proximity to each other.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 6 shows a movable chair, which comprises a leg 1 having casters on the lower surface thereof, a support cylinder 2 attached to the upper surface of the leg 1, and a support cylinder thereof. Main components are a seat portion 3 provided at the upper end of the seat 2, armrests 4 standing upright on both left and right sides of the seat portion 3, and a backrest portion 5 standing upright on the rear side of the seat portion 3.

The armrest 4 will be described in detail with reference to FIGS.
As shown in FIG. 5, an armrest portion 6 that is made of hard urethane foam or synthetic resin and is long in the front-rear direction, and a guide member 7 integrally formed on the lower surface of the armrest portion 6 in a vertical posture.
Therefore, the armrest 4 is configured. In addition to integrally forming the armrest portion 6 and the guide member 7, the two members 6 and 7 may be separately formed, and both of the separately formed members may be assembled to form the armrest 4. .

A mount 16 is provided on each of the left and right sides of the chair.
A support member 8 is erected via the guide member 7, and the guide member 7 is internally fitted in the support member 8 so as to be able to move up and down through vertical holes 7a formed therein. A rack 9 is formed by forming a large number of teeth 8a in the vertical direction on each of the front and rear side surfaces of the support member 8. Further, a pair of front and rear guide grooves 7b, 7b formed in the lower portion of the guide member 7 in the left-right direction are fitted in a pair of front and rear teeth 8a, 8a of the rack 9 in a direction parallel to the tooth surfaces. A pair of tooth portions 10 that simultaneously mesh with each other
A meshing member 10 including a and 10a is provided so as to be slidably movable. In addition to integrally forming the rack 9 on the support member 8, a separately formed rack 9 may be attached to the support member 8. The meshing member 10 has a pair of tooth portions 10a, 10a.
However, it may be implemented by providing only the tooth portion 10a on one side.

A fixed position for preventing the vertical movement of the armrest 4 by engaging the engaging member 10 with the rack 9 and the engagement between the rack 9 and the engaging member 10 are released to release the armrest 4 from the fixed position.
An operating member 11 for selectively moving the meshing member 10 is provided at a fixing release position that allows the vertical movement of the meshing member, and an elastic member that elastically biases the meshing member 10 to a fixed position that meshes with the rack 9. A spring 12 is provided between the inner surface of the guide member 7 and the engagement member 10,
By pushing the operating member 11 in the direction of the arrow against the elastic biasing force of the spring 12 from the state shown in FIG. 4, the engagement between the rack 9 and the engaging member 10 is released as shown in FIG. You can move up and down. Then, by releasing the hand from the operation member 11, the engagement member 10 is engaged with the rack 9 so that the armrest 4 can be fixed to the support member 8. Besides using the spring 12 as the elastic member, a leaf spring, elastic rubber or the like may be used.

The operating member 11 is made of steel, aluminum, or a hard synthetic resin or the like and projects into a hole 7B formed in an upper portion of the inner wall 7A of the guide member 7 located on the seat 3 side. 11A and this operation unit 11A
And a rectangular annular body 11B integrally formed on the back surface of the. By disposing the operation portion 11A in the vicinity of the armrest portion 6, when the operation portion 11A is pushed with, for example, the thumb while the armrest portion 6 is held by hand, the engagement between the rack 9 and the engagement member 10 is released. At the same time, raising and lowering the armrest portion 6 can be continuously operated with one hand. Further, the operating member 11 is constituted by the rectangular annular body 11B, so that the shape retaining strength of the operating member 11 itself is enhanced. Then, a linear tooth profile having a smaller number of teeth than the rack 9 is formed on each of the four inner side surfaces of the annular body 11B, which are located closer to the spring 12 side of the inner side surfaces 11b, 11b located in the front-rear direction. The tooth portions 10a, 10a that are integrally formed and project inward from the inner side surface 11b are integrally formed so that the meshing member 10 also serves as the annular body 11B. As described above, by integrally forming the operation member 11 and the meshing member 10, it is possible to reduce the size of the operation structure, and it is advantageous in terms of manufacturing work.

At the fixed position, the meshing member 10 has front and rear side surfaces of the supporting member 8, that is, a pair of teeth 8.
a, 8a, and abutment surface 11a that abuts and acts on three surfaces of one of the left and right side surfaces located on the outer side with respect to the seat portion 3.
11a, 11a are formed so that the contact surfaces 11a, 11a, 11a of the meshing member 10 reliably contact and support the rack 9.

Although the operation portion 11A is provided on the side wall 7A of the guide member 7 located on the side of the seat portion 3, the outer wall of the guide member 7 opposite to the seat portion 3 and the guide member 7 are provided. Operation part 11A such as a rear side wall located on the backrest 6 side or a front side wall located on the opposite side of the guide member 7 from the backrest part 6
The installation location of is not limited to the guide member 7, and may be provided at any location as long as it is a member constituting a chair.

An upper open type skirt member 15 for covering the support member 8 is provided, and the skirt member 15 is provided.
Is inserted into the support member 8 from above through the opening 15a formed in the bottom plate portion 15A thereof, and the skirt member 15 is slidable in the annular upper and lower grooves 7C formed on the outer peripheral surface of the guide member 7. It is fitted. A cover member 17 for covering the skirt member 15 is provided on the outer surface of the skirt member 15.
Is externally fitted and fixed to the upper portion of the guide member 7 slidably with respect to the skirt member 15. Further, a protrusion formed on the inner surface of the lower end of the cover member 17 is in sliding contact with the outer surface of the skirt member 15 when the guide member 7 is moved up and down, and is formed on the upper end of the skirt member 15 when the guide member 7 is lifted. A stopper member 18 made of synthetic resin, elastic rubber, or the like, which is in contact with the lower edge of 15b and regulates the maximum rising position of the guide member 7, is fixed. Therefore, armrest 4
The skirt member 15 prevents the rack 9 of the support member 8 from being exposed by the upward movement of the armature 4, and ensures that the inner surface of the cover member 17 and the outer surface of the guide member 7 slide and move when the armrest 4 moves up and down. I have to. Upper and lower grooves 15B are formed on the side wall of the skirt member 15 on the seat portion 3 side to allow the operation portion 11A to move when the guide member 7 is moved up and down. Further, a hole 17A for exposing the operation portion 11A is formed on the side wall of the cover member 17 on the seat portion 3 side. By providing the outer surface of the cover member 17 and the pressing surface of the operating portion 11A so as to be flush with each other, it is possible to prevent the operating portion 11A from being touched by a hand or being accidentally brought into contact with another object and pushed. However, the pressing surface of the operation portion 11A may be provided so as to project outward from the outer surface of the cover member 17. Although not shown, a spring for urging the guide member 7 to move upward is provided between the lower end surface of the guide member 7 and the bottom plate portion 15A of the skirt member 15 so that the armrest 4 can be lifted and lowered easily. It may be possible to perform it by operating force.

The operation portion 11A and the meshing member 10 may be separately formed, and both of them may be attached to the guide member 7, respectively. For example, as shown in FIGS. 7 to 10, a pair of idle gears 13 and 13 meshing with the rack 9 is provided on an operating member 11 having an operating portion 11A protruding from a hole 7B formed in the side wall 7A of the guide member 7. And a U-shaped meshing member 10 having a pair of tooth portions 10a, 10a having a straight tooth profile are integrally screwed together with a screw 14. This is achieved by locating the meshing member 10 in front of the rack 9 by the urging force of the spring 12 provided between the inner surface of the guide member 7 and the back surface of the meshing member 10 as shown in FIG. A fixed position that prevents the armrest 4 from moving up and down, and the operating portion 1 against the biasing force of the spring 12.
By pushing 1A in the direction of the arrow shown in FIG. 9, the meshing member 10 is moved to the position laterally displaced from the rack 9 as shown in FIG. 10, and the pair of idle gears 13 and 13 is moved. By positioning it in front of the rack 9, it is possible to integrally move the idler gears 13, 13 and the meshing member 10 to a fixed release position that allows the two to mesh with each other to allow the armrest 4 to move up and down. There is. The rack 9 is meshed with the pair of idler gears 13, 13 to make the armrest 4
By moving the armrest 4 up and down, the sliding contact movement resistance of the armrest 4 can be reduced, the lifting operation of the armrest 4 can be performed lightly, and the armrest 4 can be reliably moved up and down by meshing between the pair of idler gears 13, 13 and the rack 9. Can be guided to move. The members of which numbers are omitted are the same as the members of the same numbers shown in FIGS.

Although the rack 9 is provided on the support member 8, the rack 9 may be provided on the guide member 7. For example, as shown in FIGS. 11 and 12, a rack 9 is formed on a guide member 7 provided on the lower surface of the armrest 4 so that the guide member 7 can be moved up and down with respect to the support member 8 while being fitted therein. An upper end of the support member 8 is formed with a vertical insertion hole 8A for the guide member 7, and the support member 8 is formed.
An operating member 11, a meshing member 10, and a spring 12 are provided on the. Therefore, the hole 8 formed in the side wall 8B of the support member 8
By pushing in the operation portion 11A of the operation member 11 protruding from b against the urging force of the spring 12, the engagement member 10 is moved to the position laterally displaced from the rack 9 and a pair of idle rotations are performed. By positioning the gears 13 and 13 in front of the rack 9 to bring them into mesh with each other to bring them to a fixed release position that allows the armrest 4 to move up and down, and if the operator releases the operating portion 11A of the operating member 11,
As shown in FIG. 12, the engagement member 10 is positioned in front of the rack 9 by the urging force of the spring 12 so that the engagement member 10 is engaged with each other and is positioned at a fixed position that prevents the armrest 4 from moving up and down. The members of which numbers are omitted are the same as the members of the same numbers shown in FIGS.

FIGS. 13 and 16 show another embodiment of the armrest 4, and the armrest 4 will be described next. The armrest portion 6, a guide member 7 integrally formed on the lower surface of the armrest portion 6 and having a semicircular cross section with one side open, a cover member 19 for closing the open side of the guide member 7, and the seat portion 3
The armrest 4 is configured by using the three plates 21, 22, and 23 that form the support member 8 that are bolted to the fixed base table 20 as main components. In addition, 29 shown in the figure
Is a sheet-like member that is interposed between the plates 21 and 22 to enhance the adhesion.

On the upper half of the inner surface of the guide member 7, a plate-like lever 25, which is interlockingly connected with a lock release operation knob 24 provided in an opening 7K formed in the guide member 7, is slidably guided. A convex portion 26 is formed for the guide member 38, and a rectangular concave portion 28 for accommodating the meshing member 10 is provided immediately below the convex portion 26 of the guide member 38, and the meshing member 10 is urged to move outwardly of the concave portion 28. For this purpose, a circular recess 30 for accommodating the spring 12 functioning as the elastic member is formed. A pair of holders 27A and 27B for guiding the rack 9 which is fixed to the base stand 20 by bolts together with the plates 21, 22 and 23 are screwed to both sides of the convex portion 26 of the guide member 7. ing.

At the lower end of the lever 25, the engaging member 10
A slide member 31 for moving and operating the inside of the recess 28 against the urging force of the spring 12 is fixed with a screw. Further, one end of a spring 32 for urging the lever 25 to move downward acts on the upper end of the lever 25.

The joint member 33 is screwed to the inner surface of the cover member 19, and the tip of the joint member 33 is locked to the holders 27A and 27B, so that the cover member 19 is fixed to the guide member 7. I am trying to fix it.

As shown in FIGS. 14 and 15 (a), (b), the first tooth surface located on the upper side of the pair of tooth surfaces 9A, 9B extending from the tooth tip 9a side toward the tooth groove 9b side. 9A is formed in a shape along the horizontal direction orthogonal to the vertical direction, and the second tooth surface 9B located on the lower side is provided with a large number of tooth profiles formed on the inclined surface closer to the tooth groove 9b on the tooth groove 9b side. A pair of tooth surfaces 9C and 9D are provided from both the tooth top 9a side to the tooth groove 9b side while the first rack portion 9X is provided on both sides.
Among them, the third tooth surface 9C located on the upper side is formed on the inclined surface closer to the tooth groove 9b on the tooth groove 9b side, and the fourth tooth surface 9D located on the lower side is horizontal in the vertical direction. The second rack portion 9Y having a large number of tooth shapes formed along the direction is provided at the inner side position of each of the first rack portions 9X, 9X to form the rack 9.

It has a first meshing tooth surface 10A along the horizontal direction that meshes with the first tooth surface 9A, and the second tooth surface 9B.
With a plurality of tooth profiles having inclined tooth surfaces 10B parallel to the first
The engaging portions 10b are provided on both sides, and the first
A second meshing tooth surface 1 along the horizontal direction that meshes with the fourth tooth surface 9D when the tooth surface 9A meshes with the first meshing tooth surface 10A.
Inclined tooth flank 10 having 0C and parallel to the third tooth flank 9C.
A second meshing portion 10c having a large number of D-shaped teeth is provided at an inner position of each of the first meshing portions 10b and 10b, and a meshing member 10 that meshes with the rack 9 is configured. Therefore, as shown by the two-dot chain line in FIG.
When the first meshing tooth surface 10A meshes with the first tooth surface 9A, the downward movement of the meshing member 10 is prevented, and as shown by the two-dot chain line in FIG. As the second meshing tooth surface 10C meshes with 9D, the meshing member 10 is prevented from moving upward, and the armrest 4 is prevented from moving up and down. A single tooth profile having a first meshing tooth surface 10A and an inclined tooth surface 10B of the meshing member 10 is provided, and a second meshing tooth surface 10C of the meshing member 10 is provided.
Alternatively, a single tooth profile having the inclined tooth surface 10D may be provided. Further, the inclined tooth surfaces 10B and 10D may be changed to a curved shape or a sawtooth shape.

Explaining the height adjustment of the armrest 4,
The lever 25 is slid upward by operating the unlocking operation knob 24 upward.
At this time, the slanted contact surface 31A of the slide member 31 presses the slanted contact surface 10H of the meshing member 10 into contact, and the meshing member 1
0 moves to the inner side of the recess 28 against the urging force of the spring 12, the meshing between the meshing member 10 and the rack 9 is released, and the armrest 4 is allowed to move up and down. After raising and lowering the armrest 4 to a desired height, the lever 25 is released by releasing the lock release operation knob 24.
Moves downward due to the urging force of the spring 32, and accordingly, the engaging member 10 moves toward the outside of the recess 28 due to the urging force of the spring 12, and the engaging member 10 and the rack 9
And are in mesh with each other to prevent the armrest 4 from moving up and down.

The first tooth surface 9A of the rack 9 and the meshing member 1
The meshing width W1 with the first meshing tooth surface 10A of 0 is the fourth meshing tooth surface 9D of the rack 9 and the second meshing tooth surface 10 of the meshing member 10.
It is wider than the engagement width W2 with C, and even if a large load acts on the armrest 4 such as the weight of the arm resting on the armrest 4, the engagement between the rack 9 and the engagement member 10 is disengaged, It is possible to minimize the size of the meshing portion on the side where a large load is not applied during normal use, while preventing the meshing portion from being damaged.

As shown in FIG. 17, the cover member 19 has a scale plate 3 attached to the plate 23.
4 is formed with an opening 19A through which the user can see the scale plate 34, and by looking at the scale plate 34 through the opening 19A,
The height position of the armrest 4 can be confirmed. By opening a portion of the cover member 19 inward and then opening the opening portion 19A, the opening portion 19A can be brought closer to the scale plate 34. Moreover, the inclined surface 1 forming the recessed portion
9B is configured to be inclined by an angle K (about 76 degrees) with respect to the direction orthogonal to the outer surface of the cover member 19 as shown in the figure, and the scale plate 34 is visually recognized over a wide range. I am able to

A rack 9 is provided to prevent the armrest 4 from rising.
Two meshing portions are provided between the meshing member 10 and the meshing member 10, and the rack 9 and the meshing member 1 are provided to prevent the armrest 4 from descending.
Two meshing parts with 0 are provided, but the number of meshing parts with the rack 9 and the meshing member 10 is not limited to these. For example, as shown in FIG. 18, the second rack portion 9Y is formed in the left-right center portion of the surface of the rack 9, and the first rack portion 9X is formed on both lateral sides of the second rack portion 9Y. There is. Then, the first rack portion 9
Engagement member 10 having a tooth profile that meshes with each X tooth profile
Is provided with a lever 25 for pulling and biasing the engaging member 10 toward the guide member 7 side by the biasing force of the spring 35 and moving the meshing member 10 to the side that meshes with the rack 9 against the biasing force of the spring 35. A spring 36 for urging the downward movement is provided, and the lock releasing knob 24 attached to the upper end of the lever 25 is moved upward to move the inclined contact surface of the slide member 31 at the lower end of the lever 25. 31A releases the contact pressure of the engagement member 10 against the inclined contact surface 10H, and the engagement member 10 is pulled and moved toward the guide member 7 side by the urging force of the spring 35. At this time, the engagement between the engagement member 10 and the rack 9 is released, and the armrest 4 can be moved up and down. When the lever 25 is moved downward by the biasing force of the spring 36 by releasing the hand from the unlocking knob 24, the engaging member 10 is moved to the side that meshes with the rack 9 against the biasing force of the spring 35. The armrest 4 is moved so that the armrest 4 is prevented from moving up and down. The spring 36 is referred to as an elastic member that elastically biases the engaging member 10 to the fixed position.

[0031]

According to the first aspect of the present invention, since the meshing range with the rack can be made wider than in the conventional case, the vertical position of the armrest can be unexpectedly changed without increasing the elastic biasing force of the elastic member. It is possible to provide an armrest for a chair that is capable of reliably avoiding this, and that is also excellent in operability and that allows the operation member to be operated lightly when adjusting the height of the armrest.

According to the second aspect, by engaging the rack and the meshing member in the direction orthogonal to the raising / lowering direction of the armrest, the raising / lowering of the armrest can be prevented more reliably, so that the vertical position of the armrest is unexpectedly changed. It is possible not only to more reliably avoid that the chair is lifted, but also to prevent the armrest from coming off when moving the chair by lifting the armrest, so that the chair can be used comfortably. Armrests can be provided. Moreover, there is also an advantage that the rack and the meshing member can be smoothly meshed with each other by the inclination guide action of the second tooth surface and the third tooth surface.

According to the third aspect, even if a large load is applied to the armrest during use, the rack and the meshing member are not disengaged from each other, and the meshing portions thereof are not damaged, so that the armrest can be properly prevented from descending. Although it is possible to reduce the size of the meshing part on the side that prevents the armrest from moving upward, it is possible to prevent the size of the entire device from increasing and to use it for a long period of time. Can be done.

According to the fourth aspect of the present invention, by making the moving direction of the meshing member different from the direction in which the external force acting on the armrest is directly transmitted, the elastic biasing force of the elastic member is indirectly transmitted by fine vibration or the like. Even if it is set to a very small force that prevents the member from moving, it is possible to reliably avoid accidentally changing the vertical position of the armrest as in the past, and to operate the operating member with a smaller force. It can be operated with.

According to the fifth aspect, by forming teeth on the supporting member itself to form a rack, it is possible to reduce the work steps in the manufacturing work and the work steps in the assembly work all at once. In addition, the manufacturing cost can be advantageously reduced by shortening the manufacturing time and the assembling time. Moreover, by avoiding troubles such as deformation of the rack, the meshing member abuts and supports the rack to which a large force acting when the hand is placed on the armrest is transmitted, and the rack is meshed and supported from both sides. It can be used for a long period of time.

According to the sixth aspect, by integrally forming the operating portion and the meshing member, these two members can be centrally arranged at one place, and it is not necessary to separately form both members, so that a small armrest can be provided. It is possible to reduce the number of manufacturing steps, the manufacturing steps, and the assembly steps all at once, which is advantageous in terms of cost. Moreover, by forming the member that integrally forms the engaging member from the rectangular annular body, the shape retention strength of the member can be increased, and the operating portion has excellent durability without cracking or deformation over a long period of time. Can be provided.

[Brief description of drawings]

FIG. 1 is a partially omitted exploded perspective view of an armrest.

[Figure 2] Partial cutaway side view of the armrest

[Figure 3] Partial cutaway side view of the armrest

FIG. 4 is a cross-sectional plan view of an armrest.

FIG. 5: Cross-sectional plan view of armrest

FIG. 6 is a side view of a chair.

FIG. 7 is a partially omitted exploded perspective view showing another embodiment of the armrest.

FIG. 8 is a partially cutaway vertical side view showing another embodiment of the armrest.

FIG. 9 is a cross-sectional plan view showing another embodiment of the armrest.

FIG. 10 is a cross-sectional plan view showing another embodiment of the armrest.

FIG. 11 is a partially omitted exploded perspective view showing another embodiment of the armrest.

FIG. 12 is a cross-sectional plan view showing another embodiment of the armrest.

FIG. 13 is an exploded perspective view showing another embodiment of the armrest.

FIG. 14 is a partially omitted exploded perspective view showing another embodiment of the rack and the meshing member.

15 (a) and 15 (b) are vertical side views showing another embodiment of the meshing portion between the rack and the meshing member.

FIG. 16 is a vertical sectional side view showing another embodiment of the armrest.

FIG. 17 is a vertical cross-sectional view of a main part of a cover member.

FIG. 18 is a partially omitted exploded perspective view showing another embodiment of the engagement portion between the rack and the engagement member.

[Explanation of symbols]

1 leg part 2 support tube 3 seat part 4 armrest 5 backrest part 6 armrest part 7 guide member 7A side wall 7B hole 7C vertical groove 7K opening 7a vertical hole 7b guide groove 8 support member 8A insertion hole 8B side wall 8a tooth 8b hole 9 rack 9A 1st tooth surface 9B 2nd tooth surface 9C 3rd tooth surface 9D 4th tooth surface 9X 1st rack portion 9Y 2nd rack portion 9a Tooth tip 9b Tooth groove 10 Engaging member 10A 1st engaging tooth surface 10B Inclined tooth surface 10C Second meshing tooth surface 10D Inclined tooth surface 10H Inclined abutment surface 10a Tooth portion 10b First meshing portion 10c Second meshing portion 11 Operation member 11A Operation portion 11B Annular body 11a Abutment surface 11b Inner surface 12 Spring (elastic member) 13 Idling Gear 14 Screw 15 Skirt member 15A Bottom plate 15B Groove 15b Projection 16 Mounting base 17 Cover member 17A hole 18 Stopper member 19 Cover member 19A Opening 19B Slope 20 Base base 21,22,23 Plate 24 Lock release knob ( Operating member) 25 Lever 26 Convex portion 27A, 27B Holder 28 Recessed portion 29 Port member 30 Recess 31 Slide member 31A Inclined contact surface 32 Spring 33 Joint member 34 Scale plate 35 Spring 36 Spring (elastic member) K angle W1, W2 mesh width

Claims (6)

[Claims] 1. A guide member, which is vertically installed on a lower surface of an armrest, is fitted to support members provided on both sides of a chair so as to be vertically movable, and one of the support member and the guide member is vertically moved. A rack having teeth formed on the rack is provided, and a meshing member having a smaller number of teeth than the rack meshing with the rack is provided on the other side to release the meshing between the rack and the meshing member to raise and lower the armrest. An operating member for selectively moving the engagement member is provided at an allowable release position and a fixed position at which the engagement member is engaged with the rack to prevent the armrest from moving up and down, and the engagement member is provided on the rack. An armrest of a chair provided with an elastic member that elastically urges a fixed position that meshes with. 2. The rack has a first tooth surface located on the upper side of a pair of tooth surfaces extending from the tooth crest side toward the tooth groove side, the first tooth surface being formed along the horizontal direction orthogonal to the vertical direction, and , A first rack portion having a plurality of tooth profiles formed on an inclined surface in which the second tooth surface located on the lower side is closer to the tooth groove on the tooth groove side, and a pair of tooth surfaces facing from the tooth tip side to the tooth groove side Of the above, the third tooth surface located on the upper side is formed on the inclined surface closer to the tooth groove on the tooth groove side, and the fourth tooth surface located on the lower side is along the horizontal direction orthogonal to the vertical direction. And a second rack portion having a large number of tooth profiles formed on the first tooth surface, and a first meshing member having a first meshing tooth surface along a horizontal direction in which the meshing member meshing with the rack meshes with the first tooth surface. And the fourth tooth surface when the first tooth surface and the first tooth surface engage with each other. The armrest of the chair according to claim 1, further comprising a second meshing portion having a second meshing tooth surface extending in the horizontal direction. 3. A first tooth surface of the rack and a first meshing member.
The armrest of a chair according to claim 1 or 2, wherein an engagement width with the engagement tooth surface is wider than an engagement width between the fourth tooth surface of the rack and the second engagement tooth surface of the engagement member. 4. The engaging member is provided so as to be movable only in a direction parallel to the tooth surface of the rack, and the engaging member is located in front of the rack from a position laterally displaced from the rack. The armrest of the chair according to claim 1, wherein the armrests of the chair are configured to engage with each other. 5. A rack is formed by integrally forming teeth on both front and rear side surfaces of the support member, and one of the front and rear side surfaces and the left and right side surfaces of the support member at the fixing position is formed on the meshing member. A pair of abutting surfaces for abutting action on three side surfaces, and a pair of teeth for simultaneously engaging with teeth formed on both front and rear side surfaces of the support member in a fitted state from a direction parallel to the tooth surfaces. An armrest for a chair according to claim 1, wherein the armrest is provided with teeth. 6. The operation member comprises an operation portion facing a hole formed in a side wall of the guide member, and a rectangular annular body integrally formed on a back surface of the operation portion,
The armrest for a chair according to claim 1 or 5, wherein teeth which mesh with teeth formed on both front and rear surfaces of the support member are formed on an inner surface of the annular body to constitute the meshing member.