JP5722718B2 - Mounting structure of optional members on chair pedestals and pedestals - Google Patents

Description

  The present invention relates to a chair pedestal for attaching an optional member such as a footrest so that the height can be adjusted, and a structure for attaching the optional member to the pedestal.

  For example, some children's chairs used for learning at home have a footrest attached to a pedestal that supports the seat in case the seated child's foot does not reach the floor. Various types of footrests have been proposed in which the height can be adjusted in accordance with the growth of the child and can be removed when it becomes unnecessary (for example, Patent Documents 1 to 3). 3).

JP 2007-181614 A Utility Model Registration No. 3097290 Utility Model Registration No. 3143021

  Each of the chair pillars described in Patent Documents 1 to 3 has a columnar shape with a smooth outer peripheral surface. When the footrest is attached to the pillar, the center of the footrest is placed. By engaging the engaging recess that opens in the vertical direction and the rear formed in the part, and tightening the screw receiving member provided at the opening end of the engaging recess with the fastening means attached thereto, The height of the footrest can be adjusted by pressing the inner surface against the outer peripheral surface of the pedestal to fix the footrest to the pedestal and loosening the fastening means.

In the mounting structure of the pedestal and footrest as described in the above patent document, the footrest moves in the vertical direction only by the frictional force between the inner surface of the engaging recess and the outer peripheral surface of the pedestal. Therefore, if a child carelessly loosens the tightening means, or if the tightening means is loosened slightly while the chair is in use, the footrest will not be able to May move downward and the mounting position on the pedestal may shift.
In addition, since there is no means for positioning the footrest in the rotational direction or preventing it from rotating with respect to the pedestal, positioning work when positioning the footrest in a predetermined direction and attaching it to the pedestal is not necessary. If it is cumbersome and the tightening means is somewhat loosened, the footrest may rotate around the pedestal and be displaced.

  Also, for the purpose of adjusting the height of the footrest for children, etc., for example, on the outer peripheral surface of the pedestal, a scale that can confirm the vertical position of the footrest, a seal with a scale, etc. It is desirable to provide a part, but if such a display unit such as a scale is simply provided directly on the outer peripheral surface of the pedestal as described above, the display part is rubbed and worn away when the height of the footrest is adjusted, and the scale May be difficult to see.

  The present invention has been made in view of the above problems, and even if the tightening means is loosened, the option member is displaced with respect to the pedestal, such as moving or rotating in the vertical direction. In addition, the optional member can be stably attached to the pedestal, and the positioning at the time of attaching the optional member is easy, and the display section provided on the outer peripheral surface of the pedestal includes an optional member. It is an object of the present invention to provide a chair pedestal and a structure for attaching a footrest to the pedestal so as not to be worn away by the above.

According to the present invention, the above-mentioned problems are solved as follows.
(1) A chair pedestal on which an optional member can be attached to the outer peripheral surface, and a plurality of upper and lower arcs horizontally and circumferentially capable of selectively engaging the optional member up and down on the outer peripheral surface. An engaging groove or engaging protrusion is provided, and a concave groove facing in the vertical direction is provided in a portion where the engaging groove or engaging protrusion is not formed on the outer peripheral surface. A display unit for indicating the mounting height of the member.

With such a configuration, the optional member can be attached to the outer peripheral surface of the pedestal so that the height can be adjusted and the vertical displacement is prevented.
In addition, since the bottom surface of the recessed groove provided on the outer peripheral surface is used as a display unit indicating the mounting height of the optional member, the optional member does not come into contact with the display unit when adjusting the height of the optional member. Therefore, it is possible to prevent the display unit from being worn out and difficult to see.
Furthermore, by engaging a part of the optional member with the concave groove, the concave groove can be used as a positioning means in the rotation direction of the optional member or as a detent means.

(2) In the above item (1), both ends of the engaging groove or the engaging ridge in the length direction are terminated at both side edges of the recessed groove.

  With such a configuration, even if a wide concave groove is provided, the optional member can be engaged in a wide range with the engaging groove or the engaging protrusion across the concave groove.

(3) In the above item (1) or (2), the bottom surfaces of the engaging groove and the recessed groove are made continuous with each other.

  With such a configuration, a step does not occur in a portion where the engaging groove and the recessed groove are continuous, so that it is easy to form the pedestal and process the groove, and it is easy to visually recognize the display unit from the outside.

(4) A structure for attaching an optional member to the pedestal of the chair according to any one of (1) to (3) above, wherein the concave groove provided in the outer peripheral surface of the pedestal has a vertical thickness. An engagement recess that opens in the vertical direction and one side is provided in the mounting portion of the option member that is smaller than the vertical dimension, and the engagement recess is fitted to a chair pillar, and the engagement recess An arc-shaped engagement provided on at least one of the opposing surfaces of the pressing member and the engaging recess, with the pedestal being sandwiched between the pressing member disposed inside and the inner surface of the engaging recess facing the pressing member The engaging member or the engaging groove is selectively engaged with a plurality of upper and lower arc-shaped engaging grooves or engaging protrusions of the pedestal, and the pressing member is provided with fastening means provided on the optional member. The pressing surfaces that are tightened toward the back of the engaging recess and the pressing member and the engaging recess face each other. Is attached to the outer periphery of the pedestal so that the optional member is attached to the pedestal.

With such a configuration, the engagement ridge or engagement provided on either the inner surface of the pressing member or the inner surface of the engagement recess in the engagement groove or engagement ridge provided on the outer peripheral surface of the pedestal Even if the tightening means is loosened by attaching the option member to the outer peripheral surface of the pedestal with the tightening means in the state where the groove is engaged, there is no fear that the option member moves in the vertical direction.
Moreover, since the pressing surface of the opposing surface of a pressing member and an engagement recessed part is press-contacted to the outer peripheral surface of a pedestal, an option member can be stably and firmly attached to a pedestal.

(5) In the above item (4), engagement protrusions that engage with both side edges of the concave groove of the pedestal are provided on either one of the opposing surfaces of the pressing member and the engagement recess.

  With this configuration, the optional member can be easily attached to the pedestal by positioning it in the rotational direction with a simple configuration, and the optional member can be rotated around the pedestal even if the fastening means is loosened. Is prevented from rotating.

(6) In the above item (4) or (5), the projecting dimension of the engaging protrusion provided in the engaging recess or the pressing member is smaller than the depth of the engaging groove and the recessed groove of the pedestal.

  With such a configuration, the engaging groove of the pedestal column that is thinned by the engagement recess or the tip of the engaging ridge provided in the pressing member being in contact with the engaging groove of the pedestal column and the bottom surface of the recessed groove And since it does not press the bottom face of a ditch | groove strongly, it is prevented that a pedestal deform | transforms.

(7) In any of the above items (4) to (6), at least two upper and lower engagement ridges or engagement grooves provided on the pressing member are provided, and two upper and lower adjacent ones in the pedestal A press having a pressing surface that is selectively engaged with the engaging groove or the protruding ridge and that is in pressure contact with the outer peripheral surface of the pedestal between the two upper and lower engaging grooves or the protruding ridge. Protrusions are provided.

  With such a configuration, the option member can be more stably attached to the outer peripheral surface of the pedestal in the vertical direction, and can be attached more stably, and between the two upper and lower engaging grooves or engaging protrusions adjacent to each other. In this case, since the pressing surface of the pressing projection is in wide contact with the outer peripheral surface of the pedestal, the contact area can be increased and the frictional force can be increased.

(8) In any one of the above items (4) to (7), the optional member is a footrest.

  With such a configuration, even if the tightening means is loosened, the footrest to which the foot load is applied does not move downward, and the footrest can be stably attached to the pedestal.

According to the pedestal of the present invention, the optional member can be attached to the outer peripheral surface of the pedestal so that the height can be adjusted and the positional deviation in the vertical direction can be prevented.
In addition, since the bottom surface of the recessed groove provided on the outer peripheral surface is used as a display unit indicating the mounting height of the optional member, the optional member does not come into contact with the display unit when adjusting the height of the optional member. Therefore, it is possible to prevent the display unit from being worn out and difficult to see.
Furthermore, by engaging a part of the optional member with the concave groove, the concave groove can be used as a positioning means in the rotation direction of the optional member or as a detent means.

It is a front perspective view of a chair provided with the 1st embodiment of the present invention. Similarly, it is an enlarged perspective view of the principal part of the chair when the footrest is attached. Similarly, it is a disassembled perspective view of the principal part of the chair before footrest mounting. It is a front expansion perspective view of a press member. It is an expansion center vertical side view of a footrest mounting part. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is a cross-sectional view which follows the VII-VII line of FIG. It is a cross-sectional view of the same part as FIG. 6 in the second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a chair provided with a first embodiment of the present invention. This chair has a leg 3 composed of five leg rods 2 having a caster 1 at the front end and facing the radial direction, and a center thereof. Standing up from both sides of the pedestal 4, a seat body 5 supported by a support base (not shown) attached to the upper end of the support 4 so as to be horizontally rotatable, and a rear end of the support base A backrest 8 attached to the upper end of the backpacks 6 and 6 via backframes 7 and 7 facing a pair of left and right sides is provided.

  As shown in FIG. 5, the pedestal 4 includes an extendable leg 9 having a support base attached to the upper end, and a gas spring 10 having a lower end fixed to the center of the leg 3 and extending the extendable leg 9 accommodated therein. And a cylindrical cover leg 11 made of a synthetic resin having a lower end fixed to the center of the leg 3 so as to cover the gas spring 10.

As shown in FIGS. 3 and 6, a vertically long concave groove 12 is formed on the outer peripheral surface of the rear portion of the cover leg 11 over substantially the entire length.
Further, on the outer peripheral surface of the cover leg 11 excluding the concave groove 12, a plurality of upper and lower arc-shaped engaging grooves 13 facing the horizontal direction are connected to the concave groove 12, that is, the circumferential direction of the engaging groove 13. Are formed at regular intervals so that both ends of the groove end at both side edges of the groove 12 and the bottom surfaces of the groove 12 and the engagement grooves 13 are continuous with each other.

  The bottom surface of the concave groove 12 serves as a display unit 14 for indicating the mounting height of a footrest 18 which will be described later. In this embodiment, the height of the footrest 18 is adjusted stepwise on the display 14. A scale sticker 16 with a scale 15 as a guideline for attaching is attached. The scale 15 is attached at a position that is level with each engagement groove 13. Instead of the scale seal 16, for example, when forming the cover leg 11, a scale may be directly provided on the bottom surface of the concave groove 12.

  As shown in FIG. 6, a slit 17 directed in the vertical direction is formed on the front surface of the cover leg 11 from the vicinity of the upper end portion to the lower end, and the cover leg 11 is elastic in the direction of diameter reduction by the groove width of the slit 14. It can be deformed.

A footrest 18 as an optional member is attached to the cover leg 11 as follows.
As shown in FIGS. 2 to 7, the footrest 18 is a cover leg formed at the center thereof and having a vertical thickness smaller than the vertical dimension of the concave groove 12 provided in the cover leg 11. 11, a mounting portion 19 that can be fixed to 11, three connecting rods 20 that extend radially from the outer peripheral surface toward the front (left side in FIG. 5) and both sides of the chair, and the tips of the connecting rods 20. And a footrest portion 21 having a substantially C-shape in plan view with the attachment portion 19 as the center, and fastening means 22 for fastening the attachment portion 19 to the outer peripheral surface of the cover leg 11.

The mounting portion 19 has a pair of left and right sandwiching pieces 19a, 19a that are substantially parallel to each other and face rearward, and on the inner side, there is a U-shaped engagement concave portion 23 facing rearward and upward and downward in a plan view. The semicircular inner peripheral surface formed on the front side of the engaging recess 23 can be brought into surface contact with the outer peripheral surface of the front half of the cover leg 11.
On the inner surface of the front lower portion of the engagement recess 23, a horizontal and arcuate engagement ridge 24 is provided which can selectively engage with the plurality of upper and lower engagement grooves 13 on the front side of the cover leg 11 from the front. ing. The projecting dimension of the engaging protrusion 24 is slightly smaller than the depth of the engaging groove 13, and when the engaging protrusion 24 is engaged with the engaging groove 13, The tip is not in contact with the bottom surface of the engagement groove 13.

  Inwardly protruding portions 25, 25 project in an opposing manner on the opening end portion of the engaging recess 23, that is, on the opposing surface of the rear end portion of both clamping pieces 19 a in the mounting portion 19. On the front surface facing 4, locking projections 26, 26 facing upward and downward are provided to project forward. In addition, the dimension between the opposing surfaces of the both inward projections 26 and 26 is set to be slightly larger than the outer diameter of the telescopic leg 9 of the pedestal 4, and the attachment part 19 is connected to the telescopic leg 9 in any direction orthogonal thereto. It can be fitted even from the outside.

  In the engaging recess 23 of the mounting portion 19, a box-shaped pressing member 27 made of a synthetic resin having a U-shaped longitudinal section and a cross-sectional shape with an open front is opposed to the rear surface of the cover leg 11. Contained.

  The tightening means 22 is screwed into a synthetic resin screw receiving member 28 fitted so as to close the opening end portion behind the engaging recess 23 and a nut 35 described later. The rear portion of the pressing member 27 is fitted in a recess 28b provided on the front surface of the screw receiving member 28 so as to be relatively movable. The vertical dimension of the pressing member 27 and the screw receiving member 28 is slightly smaller than the vertical dimension so that the pressing member 27 and the screw receiving member 28 do not protrude from both the upper and lower surfaces of the mounting portion 19 when they are fitted into the engaging recess 23.

  As shown in the enlarged perspective view of FIG. 4, a pair of left and right pressing protrusions 30, 30 protrudes forward from the pressing member 27 facing the rear surface of the cover leg 11. The front surface is an arcuate pressing surface 30 a that can come into surface contact with the outer peripheral surface sandwiching the concave groove 12 on the rear surface of the cover leg 11. The left and right pressing protrusions 30 are continuous, leaving a space necessary for inserting an E-shaped ring 40, which will be described later, and the entire left and right pressing protrusions 30 are arcuate pressing surfaces 30a. You can also.

A pair of upper and lower forward pieces 31, 31 are formed integrally with the upper and lower edges of the pressing member 27 so as to sandwich the left and right pressing protrusions 30 from above and below. The front end portion of the protrusion 30 that protrudes slightly forward from the arcuate pressing surface 30a is a horizontal and circular shape that can be selectively engaged with two engagement grooves 13 adjacent to the upper and lower sides of the rear surface of the cover leg 11 from the rear. It is set as the arc-shaped engagement protrusion 31a, 31a. The projecting dimension of the engaging protrusions 31a from the arc-shaped pressing surface 30a is slightly smaller than the depth of the engaging groove 13, and the arc-shaped pressing surface 30a of the pressing protrusion 30 is formed on the outer peripheral surface of the cover leg 11. When the contact is made, the tip of the engagement protrusion 31 a does not contact the bottom surface of the concave groove 12 and the engagement groove 13.
The lower engaging protrusion 31a and the engaging protrusion 24 protruding on the inner peripheral surface of the front lower portion of the engaging recess 23 are aligned with each other at the same height.

The tightening screw 29 includes an operation knob 32 made of synthetic resin for rotating operation, and a bolt 33 facing forward with a rear portion fixed to the center of the operation knob 32 by insert molding. It is inserted from the rear into a through-hole 34 drilled in the center of the member 28 and facing in the front-rear direction, and is screwed into a nut 35 fixed inside the screw receiving member 28 by insert molding. Instead of the nut 35, a female screw hole into which the bolt 33 is screwed may be formed in the screw receiving member 28.
The tip of the bolt 33 is a small diameter shaft 33a.

  The front and rear pieces 37a, 37a on both the left and right sides of the U-shaped pressing fitting 37 in a plan view are fitted from the rear into the upper and lower elongated holes 36, 36 formed on the rear surfaces of both side portions of the pressing member 27. In addition, the front surface of the pressing metal member 37 comes into contact with the rear surface of the pressing member 27. Such a press fitting 37 may be omitted.

  A small-diameter shaft 33a of the bolt 33 is fitted in a through-hole 38, 38 formed at the center of the rear surface of the pressing member 27 and the pressing fitting 37 so as to be rotatable from the rear. By fastening the E-shaped ring 40 in the annular groove 39 at the distal end portion 33a, the fastening screw 29 is prevented from coming off backward.

Engagement holes 41 and 41 are formed in the outward projections 28a and 28a projecting from the intermediate portions on both side surfaces of the screw receiving member 28. The engagement holes 41 and 41 open rearward in the opposite direction to the locking projection 26. By engaging the engagement hole 41 with the locking projections 26, 26 facing the front of the rear end portion of the attachment portion 19, the screw receiving member 28 is moved in the vertical direction within the engagement recess 23 of the attachment portion 19. It is prevented from moving to and dropping out (see FIG. 6).
Further, the rear surfaces of the left and right outward projecting portions 28 a and 28 a abut the front surfaces of the left and right inward projecting portions 25 and 25, so that the screw receiving member 28 is prevented from coming off backward at the opening end of the engaging recess 23. Have been fitted.

  In order to attach the footrest 18 to the pedestal 4, first, the engagement recess 23 of the attachment portion 19 is fitted to the telescopic leg 9 from the front of the chair.

  Next, in this state, the pressing member 27, the pressing fitting 37, the screw receiving member 28, and the fastening screw 29 that are assembled in advance in the engaging recess 23 formed at the rear of the telescopic leg 9 are attached to the cover leg 11. Fit so as to face the rear surface. At this time, by engaging the engaging holes 41, 41 on both sides of the screw receiving member 28 with the left and right engaging protrusions 26, 26 at the opening end of the engaging recess 23, the pressing member 27, the screw The receiving member 28 and the entire fastening screw 29 are prevented from falling off from the engaging recess 23 and are temporarily held in the engaging recess 23.

  Next, the tightening screw 29 is loosened and the pressing member 27 is moved rearward to the vicinity of the rear limit. Then, the footrest 18 is lowered, and the rear surface of the engaging recess 23 in the mounting portion 19 and the front surface of the pressing member 27 are moved. Thus, the outer peripheral surface of the cover leg 11 is clamped from the front and rear.

  Subsequently, the engagement protrusion 24 on the inner surface of the engagement recess 23 and the upper and lower engagement protrusions 31 a and 31 a at the front end of the pressing member 27 are respectively connected to a plurality of upper and lower engagement grooves on the outer peripheral surface of the cover leg 11. 13 is selectively engaged from the front and rear. The pair of upper and lower engaging protrusions 31a of the pressing member 27 are engaged with the engaging grooves 13 adjacent to the upper and lower sides so as to cross the concave groove 12.

When the tightening screw 29 is tightened in this state, as shown in FIGS. 5 to 7, the pressing fitting 37 and the pressing member 27 are pushed forward by the front end surface of the bolt 33, thereby causing the engagement concave portion. An arcuate pressing surface on the front side of the cover leg 11 is formed on the outer peripheral surface on the front side of the cover leg 11, and arcuate pressing surfaces 30 a and 30 a of the left and right pressing protrusions 30 and 30 on the pressing member 27 are formed on the cover leg 11. Each of the footrests 18 is firmly fixed to an arbitrary height of the cover leg 11 by making strong surface contact with the outer peripheral surface on the rear side.
At this time, the projecting dimension of the engaging protrusions 24 and 31 a is slightly smaller than the depth of the engaging groove 13, so that the tips of the engaging protrusions 24 and 31 a are in pressure contact with the bottom surface of the engaging groove 13. There is no such thing, and a slight gap is formed on the opposing surfaces (see FIGS. 5 and 7). Therefore, the engagement groove 13 and the engagement protrusions 24 and 31a have a function as a vertical positioning means and a fall prevention means for adjusting the height of the footrest 18 in stages.

  A slit 17 is provided on the outer peripheral surface of the cover leg 11 so as to be directed in the vertical direction. Since the pressing load when the tightening screw 29 is tightened is released by the slit 17, the tightening portion of the cover leg 11 is locally oval. It is prevented from deforming into a shape or the like.

  When adjusting the height of the footrest 18, the tightening screw 29 is loosened to disengage the front and rear engaging ridges 24, 31 a from the engaging groove 13. And the fastening screw 29 may be tightened again, whereby the height of the footrest 18 can be adjusted stepwise.

  As described above, in the above embodiment, a plurality of upper and lower engaging grooves 13 facing the circumferential direction are provided on the outer peripheral surface of the cover leg 11 forming a part of the pedestal 4, and any of these engaging grooves is provided. 13, an arcuate engagement ridge 24 projecting from the inner surface of the engagement recess 23 of the footrest 18, and a pair of upper and lower arcuate engagement ridges 31 a provided at the front end of the pressing member 27, 31a is engaged and the footrest 18 is fixed to the cover leg 11, so that even if the tightening screw 29 is somewhat loosened, the footrest 18 may be displaced in the vertical direction. Absent. In particular, it is reliably prevented from moving downward due to the load or weight of the foot placed on the footrest 18.

In addition, the footrest 18 makes the inner surface of the front side of the engaging recess 23 come into surface contact with the outer peripheral surface of the front surface of the cover leg 11, and the arcuate shape of the left and right pressing protrusions 30, 30 in the pressing member 27. Since the pressing surfaces 30a and 30a are brought into surface contact with the outer peripheral surface of the rear surface side of the cover leg 11 and the cover leg 11 is clamped from the front and rear, the contact area between the footrest 18 and the pressing member 27 with respect to the cover leg 11 Therefore, the footrest 18 can be firmly fixed to the cover leg 11.
In addition, at this time, the tips of the engaging ridges 24 projecting from the inner surface of the engaging recess 23 and the upper and lower engaging ridges 31 a and 31 a of the pressing member 27 are pressed against the bottom surface of the engaging groove 13. Since the gaps are formed between them, the bottom surfaces of the recessed grooves 12 and the engaging grooves 13 that are thin in the cover leg 11 are strongly pressed by the tips of the engaging ridges 24 and 31a. In other words, the formation of the engagement groove 13 in the cover leg 11 is prevented from being deformed.

  Further, a concave groove 12 facing in the vertical direction is provided in a portion where the engagement groove 13 is not formed on the outer peripheral surface of the cover leg 11, and the bottom surface of the concave groove 12 is used as a display unit 14. Since the scale seal 16 serving as a guideline for adjusting 18 in stages is attached, when adjusting the height of the footrest 18, the surface facing the cover leg 11 in the pressing member 27, etc. The surface of the scale seal 16 is not slidably touched. Therefore, even if the height of the footrest 18 is repeatedly adjusted, the scale 15 attached to the scale seal 16 is rubbed and worn away, making it difficult to see. There is no risk of problems. The same effect can be obtained when a scale is provided directly on the display unit 14.

  FIG. 8 is a transverse plan view of the second embodiment of the present invention. In this second embodiment, one or a plurality of upper and lower surfaces are provided on the front surface of the pressing member 27 facing the concave groove 12 of the cover leg 11. An engaging protrusion 42 is provided to project forward, and the tip of the engaging protrusion 42 is engaged with the groove 12 so as to be detachable from the rear and slidable in the vertical direction. At this time, both side edges of the front end portion of the engaging protrusion 42 are engaged with both side edges of the concave groove 13 so that the front end of the engaging protrusion 42 does not contact the bottom surface of the concave groove 12. Is preferred.

  As described above, when the distal ends of the engaging protrusions 42 are engaged with both side edges of the concave groove 12, when the footrest 18 is attached to the cover leg 11, it can be positioned and the fastening screw 29. Even if the foot is loosened, the footrest 18 can be prevented from rotating around the cover leg 11. That is, by providing the engaging protrusion 42 on the pressing member 27, the concave groove 12 is replaced with the display unit 14 of the first embodiment as a positioning means in the rotational direction of the footrest 18 or as a detent means. Can be used. Even when the concave groove 12 is used as a positioning or detent means, the scale seal 16 can be attached to the bottom surface of the concave groove 12 to form the display unit 14. Also at this time, when the height of the footrest 18 is adjusted, it is possible to prevent the tip of the engaging protrusion 42 from coming into contact with the display unit 14 and the display unit 14 from being worn away.

The present invention is not limited to the above embodiment.
In the above embodiment, the concave groove 12 is provided on the rear surface of the cover leg 11, but it can be provided at any location on the outer peripheral surface of the cover leg 11. For example, when the concave groove 12 is provided on the front surface of the cover leg 11, the above-described engaging protrusion 42 is provided on the inner surface of the engaging concave portion 23 facing the concave groove 12. By engaging with, the footrest 18 can be prevented from rotating.

  Moreover, in the said embodiment, although the engagement groove | channel 13 shall make the partial circle | round | yen connected with the ditch | groove 12, it is also possible to make it the discontinuous circular arc shape which can engage at least the engagement protrusion 24 and 31a. is there.

  Furthermore, in the above embodiment, the engagement protrusions 24 and 31a are provided on the inner surface of the engagement recess 23 and the pressing member 27 of the footrest 18 and engaged with the engagement groove 13, but the engagement Either one of the ridges 24 and 31a may be omitted.

  Contrary to the above-described embodiment, the engaging groove 13 of the cover leg 11 is used as an engaging protrusion, and the engaging protrusion provided on the inner surface of the engaging recess 23 and the front surface of the pressing protrusion 30 of the pressing member 27 on this. Can be engaged.

  Two or more engaging ridges 24 provided on the inner surface of the engaging recess 23 of the footrest 18 may be provided, and two or more engaging ridges 31a provided at the tip of the pressing member 27 may be provided. is there.

In the above-described embodiment, the cover leg 11 which is a pedestal is cylindrical, but the present invention can also be applied to a pedestal having a non-circular shape such as an ellipse or a square cross section.
In the above-described embodiment, the example in which the option member is the footrest 18 has been described. However, other option members, for example, an optional member such as an article placement table or a tray on which small articles are placed or accommodated. The present invention can also be applied when mounting.

DESCRIPTION OF SYMBOLS 1 Caster 2 Leg rod 3 Leg 4 Leg column 5 Seat 6 Back rod 7 Back frame 8 Backrest 9 Retractable leg 10 Gas spring 11 Cover leg 12 Concave groove 13 Engagement groove 14 Display part 15 Scale 16 Scale seal 17 Slit 18 Footrest (optional material)
19 attachment portion 19a clamping piece 20 connecting rod 21 footrest portion 22 tightening means 23 engagement recess 24 engagement protrusion 25 inward protrusion 26 locking protrusion 27 pressing member 28 screw receiving member 28a outward protrusion 28b recess 29 tightening Attached screw 30 Pressing protrusion 30a Arc-shaped pressing surface 31 Forward piece 31a Engaging protrusion 32 Operation knob 33 Bolt 33a Small diameter shaft 34 Through hole 35 Nut 36 Long hole 37 Press fitting 37a Forward piece 38 Through hole 39 Annular groove 40 E-shaped ring 41 engagement hole 42 engagement protrusion

Claims (8)

A chair pedestal with an optional member attached to the outer peripheral surface,
Provided on the outer peripheral surface are a plurality of upper and lower circular arc-shaped engaging grooves or engaging ridges that can selectively engage the option member up and down, and that face in the circumferential direction, and the engaging grooves on the outer peripheral surface Alternatively, a leg of the chair is characterized in that a concave groove facing in the vertical direction is provided in a non-formation portion of the engaging ridge, and the bottom surface of the concave groove is used as a display portion for indicating the mounting height of the optional member. Pillar.   The chair pedestal according to claim 1, wherein both ends of the engaging groove or the engaging ridge in the length direction are terminated at both side edges of the recessed groove.   The leg of the chair according to claim 1 or 2, wherein the bottom surfaces of the engaging groove and the recessed groove are made continuous on the same surface. It is an attachment structure of the optional member to the pedestal of the chair according to any one of claims 1 to 3,
An engagement recess that opens in the vertical direction and one side is provided in the mounting portion of the optional member whose vertical thickness is smaller than the vertical dimension of the concave groove provided on the outer peripheral surface of the pedestal. The pedestal is sandwiched between the pressing member that is fitted in the leg of the chair and disposed in the engaging recess and the inner surface of the engaging recess that faces the engaging recess, and the engaging member is engaged with the pressing member. An arc-shaped engagement protrusion or engagement groove provided on at least one of the surfaces facing the recess is selectively engaged with a plurality of upper and lower arc-shaped engagement grooves or engagement protrusions of the leg column. Then, the pressing member is tightened toward the inner part of the engaging recess by the fastening means provided on the option member, and the pressing surfaces of the pressing member and the engaging recess facing each other are The optional member is attached to the pedestal by being pressed against the surface. Mounting structure of the options member to the chair of the pedestal, characterized.   The optional member for the leg of the chair according to claim 4, wherein engagement protrusions that engage with both side edges of the concave groove of the pedestal are provided on either one of the opposing surfaces of the pressing member and the engagement recess. Mounting structure.   6. An optional member for a leg of a chair according to claim 4 or 5, wherein the protruding dimension of the engaging protrusion provided in the engaging recess or the pressing member is smaller than the depth of the engaging groove and the recessed groove of the leg. Mounting structure.   There are at least two engaging protrusions or engaging grooves provided on the pressing member, and the engaging protrusions or engaging grooves are selectively engaged with two adjacent upper and lower engaging grooves or engaging protrusions on the pedestal column. And a pressing protrusion having a pressing surface pressed against the outer peripheral surface of the pedestal is provided between the upper and lower two engaging grooves or engaging protrusions. Mounting structure for optional members on chair pedestals.   The attachment structure of the optional member to the pedestal of the chair according to any one of claims 4 to 7, wherein the optional member is used as a footrest.

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