JP5479801B2 - Back support structure - Google Patents

Description

  The present invention relates to a back support structure for a chair.

  In conventional chairs, the lower part of the backrest is pivotally supported by the backrest support so that the lower part can be rotated about an axis that faces in the left-right direction, and the upper part of the backrest is slidable in the vertical direction. The lower part of the backrest is supported on the backrest support so that it can be rotated about an axis that faces in the left-right direction, and the middle of the backrest. There are those in which both side portions are slidable in the vertical direction and are supported on the upper end portion of the back support (see, for example, Patent Document 3).

Japanese Patent No. 4261001 JP 2007-319288 A JP 2003-24175 A

  In the above-mentioned Patent Documents 1 and 2, when the middle part of the backrest in the vertical direction is elastically bent backward, the upper part of the backrest can follow it. In Patent Document 3, when the intermediate portion of the backrest in the left-right direction is elastically bent backward, both sides of the backrest can follow it.

  However, when a seated person leans back and reclines backward, the upper half of the backrest elastically bends backward, and at that time, the middle part of the backrest in the left-right direction elastically bends backward. It has been found that a comfortable seating feeling can be obtained.

  From this point of view, the present invention makes it possible to obtain a comfortable seating feeling and to simplify the structure by making the upper part of the backrest and the intermediate part in the left-right direction easily elastically bent backward. And it aims at providing the support structure of the backrest which enabled it to improve assembly workability | operativity.

According to the present invention, the above problem is solved as follows.
(1) An arc-shaped bent portion is formed on both sides of the backrest so that a central portion in the vertical direction protrudes forward in a side view, and the backrest support body is formed on the rear surface of the bent portion so as to complement it. Projecting on both sides, an arc-shaped convex part projecting forward in the vertical direction in the side view is slidably fitted, and a connecting shaft projecting on the front surface of the convex part is connected to the backrest. By loosely fitting in the through hole provided in the bent part and providing a retaining means having a lateral dimension larger than the through hole at the front end part of the connecting shaft protruding forward from the bent part, the backrest can be moved in the front-rear direction. It is mounted on the back support so that it can rotate.

With such a configuration, the backrest can be rotated in the front-rear direction around the left and right convex parts, and when the seated person leans over the backrest and reclines backward, the part above the bent part Is easily elastically bent backward, and a comfortable seating feeling is obtained.
Also, through holes provided on both sides of the backrest are fitted to connecting shafts projecting on both sides of the backrest support body, and a retaining means is provided at the front end of each connecting shaft protruding forward from the through holes. By simply attaching, the backrest can be easily attached to the backrest support body, and the structure of the support portions on both sides of the backrest can be simplified.

(2) A spherical bent portion with a central portion protruding forward is formed on both side portions of the backrest, and the rear portion of the bent portion protrudes on both sides of the backrest support body to complement it. A spherical convex portion is slidably fitted, and a connecting shaft protruding from the front surface of the convex portion is loosely fitted into a through hole provided in a bent portion of the backrest, and protrudes forward from the bent portion. The backrest can be rotated in all directions with respect to each connecting shaft by providing a retaining device with a vertical and horizontal dimension larger than that of the front opening of the through hole at the front end of the connecting shaft. Attach it to the back support.

  With such a configuration, not only can the same effect as the configuration of the above item (1) be produced, but both sides of the backrest can rotate in all directions with respect to the left and right connecting shafts. When the seated person leans back, reclines back, and elastically bends so that the right and left middle part of the back is recessed backwards, both sides of the back follow it, Rotate in a plan view with respect to the connecting shaft, or move so as to be pulled inward from each other, and elastically flex backward to the middle part of the backrest in the left-right direction. It can be allowed or promoted, and a more comfortable seating feeling can be obtained.

(3) In the above item (1) or (2), a concave portion is provided on the front surface of both sides of the backrest, a bent portion is formed on the rear wall of the concave portion, and a cover fitted to the concave portion is used to Cover the front.

  With this structure, the retaining means is not exposed to the front, so that the appearance is good, and when the cushioning material is provided on the back of the backrest, the retaining means is rubbed against the rear surface of the cushioning material. It is possible to prevent the material from being damaged, or the retaining means from hitting the seated person via the cushion material and causing the seated person to feel uncomfortable.

(4) In the above item (3), the cover is provided with an elastic tongue that presses against the outer peripheral edge of the retaining means.

  With such a configuration, it is possible to prevent rattling of the backrest due to loosely fitting the connecting shaft into the through-hole of the backrest.

(5) In any one of the above items (1) to (4), the lower end portion of the backrest is engaged with the backrest support body so as to be movable in the vertical direction and immovable in the front-rear direction.

  With such a configuration, when the seated person leans back, reclines back, and the upper part of the back is rotated backward and elastically bent around the left and right convex parts, the lower end of the back Prevents the lower end of the backrest from moving forward and squeezing the waist of the seated person by restraining the part from turning forward and only allowing it to move up and down In addition, the backrest can be elastically bent backward, and a comfortable seating feeling can be given to the seated person.

  According to the present invention, a comfortable seating feeling can be obtained and the structure can be simplified by making the upper part from the middle part of the backrest and the middle part in the left-right direction easily elastically bent backward. Moreover, it is possible to provide a back support structure that can improve the assembly workability.

It is a side view of a chair provided with one embodiment of the present invention. Similarly, it is a rear view. It is the disassembled perspective view which looked at the support base and the backrest support body from diagonally forward. It is the disassembled perspective view which looked at the backrest from diagonally backward. It is the cross-sectional top view cut | disconnected by the horizontal surface containing the center axis line of the pin provided in the connection member. It is a vertical side view along the VI-VI line of FIG. It is the expansion vertical side view cut | disconnected by the vertical surface containing the center axis line of a connection shaft. It is a cross-sectional plan view which follows the VIII-VIII line of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 and 2, the chair includes a leg body 3 having five leg rods 2 having a radial shape with a caster 1 provided at the tip. In the center of the leg 3, a telescopic leg column 4 having a gas spring (not shown) is erected, and the rear part of the support base 5 is fixed to the upper end of the leg column 4.

  The support base 5 has a substantially hollow box shape with an upper surface opened, and the opening on the upper surface is covered with a detachable cover 5a (see FIG. 3).

  Inside the support base 5 is a biasing means for biasing the backrest 6 in the standing direction, that is, forward, and a biasing means for biasing the seat 7 supported by the support base 5 forward ( These are not shown in the drawings, but are not directly related to the present invention, and illustration and detailed description thereof are omitted.

  The backrest 6 is formed by encapsulating the front and rear surfaces of a synthetic resin back plate 6a having moderate elasticity with a skin material 6c via a cushion body 6b (see FIGS. 5 to 8).

  A pivot 8 having a non-circular cross section, such as an octagonal prism facing in the left-right direction, is pivotable about the central axis at the middle portion in the front-rear direction of the support base 5, and both ends are outside the both side surfaces of the support base 5. And pivoted so as to protrude in the direction (see FIG. 3).

At both ends of the pivot 8 projecting left and right from both side walls of the support base 5, shaft holes 10 are provided on the inner surfaces of both sides of the front end of the back support 9 that supports the back 6 and that are bifurcated toward the front. And the pivot 8 is configured to rotate with respect to the support base 5 together with the backrest support 9.
The shaft hole 10 is a non-circular hole that complements the end of the pivot 8.

  The pivot 8 is provided in the support base 5 by a biasing means (not shown) made of, for example, a rubber torsion spring, a torsion coil spring, or the like, that is, a direction in which the backrest 6 and the backrest support 9 stand. 1 is biased counterclockwise.

  As shown in FIG. 3, the backrest support body 9 includes bent portions 11 a and 12 a that are bent so that intermediate portions of the pair of left and right backrest support rods 11 and 12 approach each other inward. The above-mentioned shaft is attached to the inner surfaces of the front end portions of the front facing portions 11b and 11b that are bent and joined to be detachable, bent downward at the bent portions 11a and 12a toward the front, and widened toward the front and lower sides. By providing the holes 10 and 10 and fitting both the shaft holes 10 and 10 to both ends of the pivot 8 projecting left and right from the both side walls of the support base 5, both forward facing portions 11 b and 12 b It is attached to the support base 5 so as to be sandwiched from the left and right.

  The backrest 6 is supported by the upper end portions of the upward portions 11c and 12c extending so as to expand leftward and rightward from the bent portions 11a and 12a of the left and right backrest support rods 11 and 12 in the backrest support body 9. The both side parts above the lower end part are supported with a structure as described later.

A pair of upper and lower convex portions 13 and 14 and a pair of convex portions 13 and 14 between one of the opposing end surfaces of the bent portions 11a and 12a (the bent portion 11a) and the central portion of the left and right backrest support rods 11 and 12 A concave portion 15 is formed, and a pair of upper and lower concave portions 16 and 17 and a convex portion 18 that complement each of the convex portions 13 and 14 and the concave portion 15 are formed between the upper and lower portions of the other opposed end surface and the space therebetween. Is provided.
Each convex portion 13, 14, 18 has a laterally trapezoidal shape with a vertical width gradually decreasing toward the tip, and each concave portion 16, 17, 15 is expanded upward and downward toward the tip so as to complement it. A shape that opens is preferable.

  Further, a pair of left and right rib-shaped forward projecting pieces 19 and 19 facing in the up-down direction are provided on a portion of the front surface of the left and right bent portions 11a and 12a that is slightly outward from the facing surface. On the outer surfaces of the projecting pieces 19, 19, inclined surfaces 19 a, 19 a that are inclined inward toward the front in a plan view are formed.

  The left and right backrest support rods 11 and 12 are configured so that the convex portions 13 and 14 and the concave portions 16 and 17 facing each other and the concave portion 15 and the convex portions 18 are fitted to each other, and the opposite end surfaces of the bent portions 11a and 12a are closely contacted. In this state, the connecting member 20 is firmly connected to the left and right bent portions 11a and 12a from the front surface thereof with the four small screws 21 as fastening means.

  As shown in FIGS. 3 to 5, the connecting member 20 has a pair of left and right side pieces that form inclined surfaces 20 b and 20 b whose inner surface expands rearward on the rear surface of a base portion 20 a having a substantially rectangular front shape. 20c, 20c, and a rearward projecting portion 20d in the center, and pins 20e projecting outward are provided on both side surfaces of the base portion 20a.

In the example shown in the figure, the pin 20e longer than the right and left width is integrally fixed to the front surface of the base 20a so as to be laterally fixed. However, as long as it protrudes outward from both side surfaces of the base 20a. Anything can be used.
Moreover, although the cross-sectional shape of the pin 20e is an elliptical shape that is long in the vertical direction in this example, it may be an oval shape that is long in the vertical direction or a perfect circle.

  As shown in FIGS. 2 and 3, most of the rear surface of the backrest support 9 centering on the rear surfaces of the bent portions 11a and 12a of the left and right backrest support rods 11 and 12 coupled to each other is substantially X in the rear view. It is covered with a cover 22 made of soft synthetic resin.

  Since the backrest support 9 is configured as described above, the bent portions of the backrest support rods 11 and 12 are configured so that the support base 5 is sandwiched from the left and right at the front end portions of the left and right backrest support rods 11 and 12. 11a and 12a are brought into contact with each other so that the backrest support rods 11 and 12 can be easily attached to the support base 5 and connected to each other at the same time, thereby improving the assembling workability. At the same time, since the bent portions 11a and 12a where stresses in the backrest support rods 11 and 12 are concentrated are coupled to each other, the rigidity of the portions is increased and the backrest 6 can be strongly supported.

Accordingly, the pivot shaft 8 facing in the left-right direction is mounted on the support base 5 so that both end portions thereof protrude from the outer surface of the support base 5, and the left and right backrest support rods 11, 12 are attached from both sides thereof. The front end portion can be easily mounted so that the shaft hole 10 is fitted to both ends of the pivot shaft 8, and the pivot shaft 8 can be attached to the front end portions of the left and right backrest support rods 11 and 12 as in the prior art. And it is not necessary to insert from the side so that the support base 5 arrange | positioned between them may penetrate in the left-right direction.
Also, the structure is simple and can be manufactured at low cost.

  Furthermore, each convex part 13,14,18 is fitted to each corresponding concave part 16,17,15, and the inclined surfaces 20b, 20b of the left and right side pieces 20c, 20c are connected to the left and right backrest support ridges 11, 12, the base portion 20a of the connecting member 20 is brought into contact with the inclined surfaces 19a, 19a of the forward projecting pieces 19, 19 provided on the front surfaces of the bent portions 11a, 12a, with the small screws 21 serving as fastening means. By tightening to the front surface of 11a, 12a, the inclined surfaces 20b, 20b and the inclined surfaces 19a, 19a slide with each other, and the left and right bent portions 11a, 12a are attracted to each other, and the convex portions 13, 14, The bent portions 11a and 12a are positioned in the vertical direction by the fitting of the recess 18 and the concave portions 16, 17, and 15, and the bent portions 11a and 12a are securely and firmly coupled to each other. Thereby, it is possible to prevent the load from being concentrated on only one of the left and right backrest support rods 11 and 12.

After the bent portions 11a and 12a in the left and right backrest support rods 11 and 12 are joined to each other, and the cover 22 is attached to the rear surfaces thereof, the joint portions of the bent portions 11a and 12a are not exposed to the rear. , Good appearance.
Further, the connecting member 20 is covered with the bent portions 11a and 12a and the cover 22 in the backrest support rods 11 and 12 at the rear, and the front is covered with the lower portion of the backrest 6 as described later, and is exposed in the front-rear direction. The appearance is good.

  As shown in FIGS. 4 to 6, a rectangular base piece 23 a that is long in the left-right direction of the locking member 23 is formed on the rear surface of the middle part in the left-right direction at the lower end of the backrest 6. It is fixed with.

  The locking member 23 includes the base piece 23a, a forward projecting piece 23b that protrudes forward from the front surface of the lower end of the base piece 23a and engages with the lower edge of the backrest 6, and both side portions of the base piece 23a. A pair of left and right locking pieces 23c, 23c that protrude further rearward in a laterally downward shape and can be engaged with both sides of the pin 20e of the connecting member 20 from above, and the locking pieces 23c, 23c And a pair of left and right side pieces 23d and 23d that cover both outer side surfaces of the pin 20e engaged with the pin 20e.

  By engaging the left and right locking pieces 23c, 23c of the locking member 23 with both sides of the pin 20e from above, the lower end of the backrest 6 cannot move in the front-rear direction and slides in the vertical direction. Further, it is linked to the bent portions 11a and 12a of the backrest support body 9 so that it can be slightly rotated in the front-rear direction around the pin 20e.

  In addition, the protrusion which protruded the pin 20e on both the left and right side surfaces is provided on the rear surface of the lower end of the backrest 6, and the locking member 23 is vertically moved so that the locking pieces 23c and 23c form a vertical shape when viewed from the side. It can also be reversed and provided on the front surface of the back support 9, for example, integrally with the connecting member 20.

Next, referring to FIGS. 4, 7, and 8, a connection structure between the upper end portions of the backrest support rods 11 and 12 and the left and right side portions above the lower end portion of the backrest 6 will be described.
Spherical bent portions 25 having a central portion projecting forward in an arc shape in a side view and a plan view are formed at substantially the center in the vertical direction of the back plate 6a on both sides of the backrest 6.

  On the rear surface of each bent portion 25, a central portion protrudes forward in an arc shape in a side view and a plan view, which is provided as a separate projection on the front surface of the upper end portions of the back support rods 11, 12 to complement it. A spherical convex portion 26 is slidably fitted, and a connecting shaft 27 protruding from the front surface of the convex portion 26 is provided on the bent portion 25 of the back plate 6a, and is tapered toward the front. A retaining means that loosely fits in the through hole 28 that expands to the front, and has a larger vertical dimension and lateral dimension than the front end opening of the through hole 28 at the front end portion of the male screw portion 27a of the connecting shaft 27 protruding forward from the bent portion 25. By screwing and fixing the plate nut 29 constituting the backrest, the both sides of the backrest 6 can be rotated in all directions around the center of curvature of the front surface of the bent portion 25 and the convex portion 26. 11 and 12 are attached to the upper end portions.

  A spacer sleeve 30 is provided between the upper end front surface of the backrest support rods 11 and 12 and the rear surface of the plate nut 29 so as to penetrate the convex portion 26 and the through hole 28 of the bent portion 25. In this spacer sleeve 30, a connecting shaft 27, which is a bolt penetrating from the rear, is inserted into the upper end portions of the backrest support rods 11, 12 so that the plate nut 29 can be prevented from being overtightened.

  In addition, the bent portion 25 is not spherical, but has an arc shape in which the central portion protrudes forward only in a side view, and the convex portion 26 fitted to the rear surface also protrudes forward in only the side view. Furthermore, the through-hole 28 is a long hole that is long in the vertical direction, and both side portions of the backrest 6 are only around the axis that faces the left and right direction passing through the center of curvature of the front surface of the bent portion 25 and the convex portion 26. You may attach to the upper end part of the backrest support rods 11 and 12 so that rotation is possible.

A square recess 31 is provided on the front surface of both sides of the back plate 6a, a bent portion 25 is formed on the rear wall of the recess 31, and a lid-like cover 32 fitted to the recess 31 from the front prevents the recess. The front of the plate nut 29 as a means is covered.
By providing the cover 32, the plate nut 29 is not exposed to the front, so that the appearance is good, and the rear surface of the cushion body 6b provided on the front surface of the back plate 6a is a means for preventing the plate nut 29 and the like from coming off. It is possible to prevent the cushion body 6b from being damaged by being rubbed and the retaining means hitting the seated person via the cushion body 6b and the skin material 6c and causing the seated person to feel uncomfortable.

  Further, the plate nut 29 can be prevented from rotating by pressing the rear end portion of the elastic tongue 32 a extending from the lower part of the back surface of the cover 32 toward the rear upper side against the lower edge of the plate nut 29. Further, rattling of the backrest 6 caused by loosely fitting the connecting shaft 27 in the through hole 28 can be prevented. Further, the elastic tongue piece 32a urges the plate nut 29 upward and urges the backrest 6 downward by the reaction force, so that the backrest 6 is always located at the lower limit position. When the upper part of the backrest 6 is pushed backward by the seated person's back, the elastic tongue 32a is elastically deformed, and an appropriate resistance can be applied to the rearward tilt of the upper part of the backrest 6. It is like that.

  The elastic tongue 32 a extends from the upper part of the back surface of the cover 32 toward the rear upper side, and is provided so as to be in pressure contact with the upper edge or other outer peripheral edge of the plate nut 29 or from the upper and lower parts of the back surface of the cover 32. The plate nut 29 may be provided so as to extend rearward and upward and to hold the plate nut 29 from above and below.

By supporting the backrest 6 with respect to the backrest support body 9 as described above, the backrest 6 can be rotated in the front-rear direction around the left and right convex portions 26, and the seated person can When the heel 6 is turned and reclined backward, the portion above the bent portion 25 is easily elastically bent backward, and a comfortable seating feeling is obtained.
Further, the through holes 28 provided on both sides of the back plate 6a are fitted to the connecting shafts 27 protruding on both sides of the backrest support rods 11 and 12, and the connecting shafts 28 protruding forward from the through holes 28 are fitted. The backrest 6 can be easily attached to the backrest support 9 by simply attaching the retaining means to the front end of the backrest, and the structure of the support portions on both sides of the backrest 6 can be simplified.

  Further, since both sides of the backrest 6 can rotate in all directions with respect to the left and right connecting shafts 27, 27, the seated person can lean on the backrest 6 and recline backward, When the middle part is elastically bent so as to be recessed backward, both sides of the backrest 6 follow it and rotate so as to form a C shape in plan view with respect to the left and right connecting shafts 27, 27. Or by moving them so as to be drawn inwardly, allowing the elastic bending to the rear of the middle part of the backrest 6 in the left-right direction, and promoting it. Is obtained.

  In addition, the lower end of the backrest 6 has the above-described configuration and is linked to the bent portions 11a and 12a of the backrest support body 6, so that the seated person can lean over the backrest 6 and recline backward, When the upper part of the backrest 6 is rotated backward and elastically bent around the left and right convex parts 26, 26, the lower end part of the backrest 6 is restrained from rotating forward, and the vertical direction It is possible to prevent the lower end portion of the backrest 6 from moving forward and press the waist of the seated person, and the backrest 6 is elastically bent rearward. The seating person can be given a comfortable seating feeling.

  In addition, after engaging the locking member 23 with the left and right pins 20e from above and below, the left and right sides above the lower end of the backrest 6 are connected to the both sides of the upper portion of the backrest support 9, and By simply attaching in this way, the backrest 6 can be easily and stably assembled to the backrest support 9.

  Furthermore, since the pin 20e (or locking member) can be integrally formed with the connecting member 20 that joins the left and right backrest support rods 11 and 12, the number of parts can be reduced and the structure can be simplified. Can be manufactured at low cost.

  The present invention is not limited to the above-described embodiment, and can be implemented in various modified forms.

DESCRIPTION OF SYMBOLS 1 Castor 2 Leg 3 Leg 4 Pillar 5 Support 5a Cover 6 Backrest 6a Backboard 6b Cushion 6c Skin material 7 Seat 8 Axis 9 Backrest support 10 Shaft hole 11, 12 Backrest support rod 11a, 12a Bending part 11b, 12b Forward part 11c, 12c Upward part 13, 14 Convex part 15 Concave part 16, 17 Concave part 18 Convex part 19 Forward projecting piece 19a Inclined surface 20 Connecting member 20a Base part 20b Inclined surface 20c side piece 20d Portion 20e pin 21 small screw 22 cover 23 locking member 23a base piece 23b forward projecting piece 23c locking piece 23d side piece 24 small screw 25 bent portion 26 convex portion 27 connecting shaft 27a male screw portion 28 through hole 29 plate nut 30 spacer sleeve 31 recess 32 cover 32a elastic tongue

Claims (5)

Arc-shaped bends with the center in the vertical direction projecting forward in a side view are formed on both sides of the backrest, and on the back surface of the bends, on both sides of the backrest support to complement it A protruding arc-shaped convex portion protruding in the front in the vertical direction in a side view is slidably fitted, and a connecting shaft protruding from the front surface of the convex portion is used as a bent back portion. The backrest can be rotated in the front-rear direction by providing a loosening-prevention means that is loosely fitted in the provided through-hole and protrudes forward from the bent portion and has a larger left-right dimension than the through-hole. A support structure for a backrest characterized by being mounted on a backrest support body.   A spherical bend with a central portion protruding forward is formed on both sides of the backrest, and a spherical shape projecting on both sides of the backrest support to complement the bend on the rear surface of the bend. A connecting shaft that is slidably fitted into the convex portion, and that is connected to the through hole provided in the bent portion of the backrest, and the connecting shaft that protrudes forward from the bent portion. The back end can be rotated in all directions with respect to each connecting shaft by providing a retaining means having a vertical and horizontal dimension larger than that of the front end opening of the through hole at the front end. A back support structure characterized by being mounted on a support.   3. A backrest according to claim 1 or 2, wherein a recess is provided on the front surface of both sides of the backrest, a bent portion is formed on the rear wall of the recess, and a cover fitted to the recess covers the front of the retaining means. Support structure.   4. The back support structure according to claim 3, wherein the cover is provided with an elastic tongue that presses against an outer peripheral edge of the retaining means.   5. The backrest support structure according to any one of claims 1 to 4, wherein a lower end portion of the backrest is engaged with the backrest support so that the lower end of the backrest is movable in the vertical direction and not movable in the front-rear direction.

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