JP2018057785A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve mobility when a user moves while sitting on a chair.SOLUTION: A chair 1 has: a seat 10 having a seat surface 11 facing upward; a backrest 20 provided for a rear end side of the seat 10; and a support structure 30 movably supporting the seat 10 and the backrest 20 with respect to a floor surface F. The support structure 30 has: front wheels 31 capable of contacting the floor surface F; rear wheels 32 which are arranged at the back of the front wheels 31 and are provided in the way that they normally contact the floor surface F; and a rear support part 33 which is arranged at the back of the rear wheels 32 and can contact the floor surface F. A pair of front wheels 31 and rear wheels 32 are provided apart from each other in a width direction Dh. A central axis O32 of the rear wheels 32 is arranged ahead of the rear end part of the seat 10. In a lateral view seen from the width direction Dh, a line segment L1 connecting a lower end of the front wheels 31 and a lower end of the rear support part 33 is arranged above the lower end of the rear wheels 32.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a chair.

  2. Description of the Related Art Conventionally, in offices and conference rooms, chairs that have casters and wheels and are configured to be movable on the floor are used. For example, Patent Documents 1 and 2 describe a chair provided with legs with casters.

  The chairs described in Patent Documents 1 and 2 include a leg body having two left and right front legs and two right and left rear legs, and a seat plate supported by the leg bodies. Casters are respectively attached to the lower ends of the front legs and the rear legs. The rear legs are inclined downward and extend downward with respect to the seat plate, and the casters of the rear legs are located behind the rear end portion of the seat plate.

  A user sitting on such a chair can move on the floor while sitting on the chair. For example, the user can move the chair so that the chair is pulled forward by bending the foot while tilting the upper body forward with the entire sole of the foot or the heel in contact with the floor surface. In addition, the user can move in the direction inclined to the side by arranging the feet in the direction inclined to the side with respect to the front and performing the same operation as described above. In such an operation, the user performs an operation of twisting his / her body around an axis extending vertically from his buttocks to the waist, and following this, the chair is It rotates around the axis that passes from the buttocks to the waist and changes its direction.

Japanese Patent No. 4256041 No. 7-50987

  In the chairs described in Patent Documents 1 and 2 described above, the casters of the rear legs are arranged at positions rearward from the rear end portion of the seat plate on which the user sits. For this reason, the follower caster does not follow the twisting motion centered on the axis passing from the user's buttocks to the waist, and there is room for improvement in chair mobility.

  This invention is made | formed in view of said situation, and it aims at providing the chair which can improve the mobility at the time of a user moving while sitting on a chair.

According to one aspect of the present invention, a chair has a seat having a seating surface facing upward, a backrest provided on the rear end side of the seat, and the seat and the backrest are movable with respect to an installation surface. And a support structure for supporting. The support structure includes a front wheel that can contact the installation surface, a rear wheel that is disposed rearward of the front wheel and is always in contact with the installation surface, and is disposed rearward of the rear wheel. And a rear support portion capable of contacting the installation surface. A pair of at least one of the front wheel and the rear wheel is provided apart from each other in the width direction of the seat.
A central axis of the rear wheel is disposed in front of a rear end portion of the seat or a rear end portion of the backrest. In a side view as viewed from the width direction, a line segment connecting the lower end of the front wheel and the lower end of the rear support portion is disposed above the lower end of the rear wheel.

  According to such a chair, since the central axis of the rear wheel is arranged in front of the rear end of the seat or the rear end of the backrest, the position of the central axis of the rear wheel in the front-rear direction of the seat is From the user's buttocks while sitting on the chair, it is close to the waist. Therefore, since the distance between the user's body motion axis and the rear wheel following the motion is shortened, the rear wheel easily follows the user's motion, and the mobility of the chair can be improved. In addition, since the rear support portion is disposed behind the rear wheel, the chair can be prevented from falling by contacting the installation surface even when the chair is tilted rearward.

  In the chair, a pair of the front wheel and the rear wheel may be provided apart from each other in the width direction. The pair of rear wheels may be positioned between the pair of front wheels in the width direction.

  According to such a chair, since the front wheel and the rear wheel are provided in a pair spaced apart in the width direction, the seat and the backrest can be supported more stably. In addition, since the pair of rear wheels are positioned between the pair of front wheels in the width direction, the distance between the front wheels in the width direction can be made larger than that of the rear wheels. Thereby, since it is possible to secure a sufficient space for placing the user's foot between the pair of front wheels, it is possible to make the front wheel less likely to contact the foot to be moved when the user moves while sitting on the chair. And the mobility of the chair can be further improved.

  In the chair described above, the rear support part may be an auxiliary wheel capable of contacting the installation surface.

  According to such a chair, since the rear support portion is an auxiliary wheel, the chair can be moved by the rear wheel and the auxiliary wheel even when the chair is inclined rearward and the rear support portion is in contact with the installation surface. . Therefore, the mobility of the chair can be further improved.

  In the chair described above, the center axis of the rear wheel extends substantially along the width direction, and the relative angle between the center axis of the rear wheel and the seat may be unchanged.

  According to such a chair, since the central axis of the rear wheel extends substantially along the width direction, and the relative angle between the central axis of the rear wheel and the seat is unchanged, the rear wheel has the chair in the longitudinal direction of the seat. Rotate to move only to. Therefore, while making it easy to make a chair go straight, orientation in the case of changing direction and moving can be performed more reliably. Therefore, the mobility of the chair can be further improved.

  In the chair described above, a center axis of the rear wheel may be disposed forward of a rear end portion of the seat.

  According to such a chair, since the central axis of the rear wheel is arranged in front of the rear end portion of the seat, the position of the central axis of the rear wheel in the front-rear direction of the seat is used when sitting on the chair. The person's buttocks are closer to the waist. Therefore, since the distance between the user's body movement axis and the rear wheel following the movement becomes shorter, the rear wheel can follow the user's movement more easily, and the mobility of the chair can be further improved. it can.

  In the chair described above, the seating surface may be disposed above the rear wheel.

  According to such a chair, since the seating surface is disposed above the rear wheel, it is possible to make it difficult for the user's arm, clothes, etc. sitting on the seating surface to contact the rear wheel.

  In the chair described above, the rear wheel may be positioned between both ends of the seat in the width direction in the width direction.

  According to such a chair, since the rear wheel is located between both ends in the width direction of the seat in the width direction, the rear wheel is disposed on the inner side in the width direction of the seat. Therefore, since the rear wheel is arranged closer to the waist near the user's buttocks in the width direction, the distance between the user's body movement axis and the rear wheel following the movement is Shorter. For this reason, it becomes easier for the rear wheels to follow the movement of the user, and the mobility of the chair can be further improved.

  In the chair described above, the rear wheel may be arranged so that the entire rear wheel is covered with the seat in a plan view.

  According to such a chair, since the rear wheel is arranged so that the whole is covered with the seat in a plan view, the rear wheel is arranged directly under the seat on which the user sits. Therefore, since the rear wheel is arranged closer to the waist near the user's buttocks while sitting on the chair, the distance between the user's body movement axis and the rear wheel following the movement becomes shorter. . For this reason, it becomes easier for the rear wheels to follow the movement of the user, and the mobility of the chair can be further improved.

  In the chair described above, in a side view as viewed from the width direction, a straight line that passes through the center of gravity of the chair orthogonal to a common tangent line disposed below the front wheel and the rear wheel among the common tangent lines of the front wheel and the rear wheel. May substantially intersect the central axis of the rear wheel.

  According to such a chair, a straight line passing through the center of gravity of the chair perpendicular to a common tangent line arranged below the front and rear wheels in a side view is such that the user sits on the chair and the front and rear wheels touch the installation surface. In the state where it is, it substantially coincides with a straight line that is orthogonal to the installation surface and passes through the center of gravity of the chair. Since the rear wheel is arranged so that the straight line passing through the center of gravity substantially intersects the central axis of the rear wheel in a side view, the follower of the rear wheel to the movement of the user can be further increased, and the chair Mobility can be further improved.

  In the chair described above, the radial dimension of the rear wheel may be larger than the radial dimension of the front wheel.

  According to such a chair, since the load is more easily applied to the rear wheel than the front wheel, the stability of the chair can be increased by making the radial dimension of the rear wheel larger than the radial dimension of the front wheel. .

  In the chair described above, the support structure includes a wheel support portion that supports the front wheel and the rear wheel, and a support frame that connects the wheel support portion and the seat. The support frame includes a base end portion connected to the wheel support portion behind the front wheel and in front of the rear wheel, a skew portion extending obliquely upward toward the rear, and an upper end of the skew portion. And a seat connecting portion connected to the seat.

  According to such a chair, the skew portion of the support frame extends obliquely upward toward the rear, so that when the user is seated on the seat, the chair is moved forward. The component of the force input to is transmitted to the wheel support portion via the skew portion. The component force of the force input to the seat acts on the wheel support part that supports the front wheel and the rear wheel between the front wheel and the rear wheel from diagonally upward to diagonally downward. And pressed forward.

  In the above-mentioned chair, between the base end portion and the skew feeding portion, a lower skew feeding portion extending obliquely upward from the base end portion forward and a lower skew feeding portion are formed continuously, A curved portion that curves backward and continues to the skew portion.

  According to such a chair, the lower skewed portion extending obliquely upward toward the front is provided, and the lower skewed portion and the skewed portion are continued via the curved portion, thereby allowing the user sitting on the seat to A force that pulls the wheel support part obliquely forward acts by the vertical load. Thereby, the mobility of a chair can be improved more.

  The chair may further include a front support portion provided between a position spaced in the vertical direction between the seat and the seat in the skew portion and a front end portion of the seat. .

  According to such a chair, the seat can be stably supported by the seat connecting portion and the front support portion formed at the upper end portion of the skew portion. Further, the force input to the seat when the chair is moved forward is efficiently transmitted from the front end portion side of the seat to the skew portion via the front support portion.

  In the chair described above, the wheel support portion may have a cylindrical frame insertion portion into which the base end portion of the support frame is inserted.

  According to such a chair, when the chair is assembled, the base end portion of the support frame may be inserted into the frame insertion portion of the wheel support portion, and the assembly work can be easily performed.

  According to said chair, the mobility in case a user moves while sitting on a chair can be improved.

It is a front view of the chair concerning one embodiment of the present invention. It is a right view of the said chair. It is a top view of the chair. It is a bottom view of the chair. It is a rear view of the chair. It is sectional drawing in the AA of FIG. It is sectional drawing in the BB line of FIG. It is sectional drawing in the CC line of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 8.

FIG. 1 is a front view of a chair 1 according to the present embodiment. FIG. 2 is a right side view of the chair 1.
FIG. 3 is a plan view of the chair 1. FIG. 4 is a bottom view of the chair 1. FIG. 5 is a rear view of the chair 1. 6 is a cross-sectional view taken along line AA in FIG. 7 is a cross-sectional view taken along line BB in FIG. 8 is a cross-sectional view taken along the line CC in FIG.

In the following description, a direction perpendicular to the floor surface F, which is an installation surface on which the chair 1 is installed, is appropriately referred to as a vertical direction Dv. In addition, a direction that is orthogonal to the vertical direction Dv and that faces the front of the user when the user sits with the back on the seat of the chair 1 is referred to as a front-rear direction Df as appropriate.
In this case, the front side of the user is referred to as the front, and the opposite side is referred to as the rear. A direction orthogonal to both the up-down direction Dv and the front-rear direction Df is appropriately referred to as a width direction Dh.

  As shown in FIGS. 1 to 8, the chair 1 includes a seat 10 having a seat surface 11 facing upward, a backrest 20 provided on the rear end side of the seat 10, and the seat 10 and the backrest 20 on the floor surface. And a support structure 30 that is movably supported with respect to F.

  The seat 10 includes a seat plate 12 constituting a skeleton of the seat 10 and a seat body 13 attached to the upper surface of the seat plate 12. The seat plate 12 is made of, for example, hard resin. The seat body 13 is disposed on the upper surface of the seat plate 12, and has a cushion material (not shown) made of urethane or the like, and a tension material that covers the surface of the cushion material.

  The backrest 20 includes a frame 21 that forms a skeleton of the backrest 20 and a tension member 22 that covers the frame 21. The frame 21 is made of, for example, hard resin.

As shown in FIG. 6, the backrest 20 is connected to the rear end portion 10 r of the seat 10 by a connecting member 14. The connecting member 14 is provided at the rear end 10r of the seat 10 and extends over the entire width direction Dh of the seat 10. The connecting member 14 is fixed to the seat plate 12 with screws (not shown) or the like. Further, the lower end portion 20 b of the backrest 20 is disposed on the upper portion of the connecting member 14.
The connecting member 14 is fixed to the lower end portion of the frame 21 with screws (not shown). Thus, the backrest 20 is fixed to the seat 10.

  The seat 10 is provided with a pair of armrests 15. The pair of armrests 15 and 15 are arranged so as to sandwich the seat 10 from the width direction Dh. In the present embodiment, the pair of armrests 15, 15 are formed integrally with the connecting member 14, and are provided so as to extend forward from both ends of the connecting member 14 in the width direction Dh.

  The support structure 30 includes a front wheel 31 that can be in contact with the floor surface F, a rear wheel 32 that is disposed rearward of the front wheel 31 and is always in contact with the floor surface F, and is rearward of the rear wheel 32. And a rear support portion 33 that can be in contact with the floor surface F. The support structure 30 includes a support frame 35, a front frame (wheel support portion) 36, a support 38 (wheel support portion), and a rear frame 39. 1 to 8, the front wheel 31 and the rear wheel 32 are in contact with the floor surface F, and the rear support portion 33 is separated from the floor surface F.

  In the present embodiment, the rear support portion 33 is an auxiliary wheel 34 that can contact the floor surface F. A pair of front wheels 31, rear wheels 32, and auxiliary wheels 34 are provided apart from each other in the width direction Dh. The front wheel 31, the rear wheel 32, and the auxiliary wheel 34 are connected to the seat 10 via a support frame 35 fixed to the seat 10.

  The pair of front wheels 31, 31, the pair of rear wheels 32, 32, and the pair of auxiliary wheels 34, 34 are each configured symmetrically with respect to a plane orthogonal to the width direction Dh. The configuration will be described. Further, the side where the pair of front wheels 31 and 31, the pair of rear wheels 32 and 32, and the pair of auxiliary wheels 34 and 34 face each other is appropriately referred to as the inside of the width direction Dh, and the opposite side is the outside of the width direction Dh Is referred to as appropriate.

  The front wheel 31 can be a caster having a known configuration. The front wheel 31 is connected to the lower surface of the front end portion 36f of the front frame 36 so as to be rotatable about an axis along the vertical direction Dv. The front wheel 31 is connected to the support frame 35 via the front frame 36.

  The rear wheel 32 includes a substantially disc-shaped wheel body 37, a support body 38 that rotatably supports the wheel body 37, and a cover member 40 provided on the outer side surface of the wheel body 37 in the width direction Dh. doing. A central axis O32 serving as a rotation center of the rear wheel 32 extends substantially along the width direction Dh, and is disposed in front of the rear end portion 10r of the seat 10. The axle 38a of the rear wheel 32 extends from the support body 38 to the outside in the width direction Dh along the central axis O32. The axle 38a is fitted in a center hole 37a formed in the wheel body 37 with the center axis O32 as the center. The wheel body 37 is configured to be rotatable around the axle 38a, that is, around the center axis O32 by a bearing (not shown) provided in the center hole 37a. Further, the radial dimension of the rear wheel 32 is larger than the radial dimension of the front wheel 31.

  The support 38 is formed integrally with the rear end portion of the front frame 36. The support 38 is fixed to a support frame 35 fixed to the seat 10. Therefore, the axle 38 a is also fixed with respect to the seat 10. Therefore, the central axis O32 of the rear wheel 32 is fixed relative to the seat 10, and the relative angle between the central axis O32 and the seat 10 is unchanged. For this reason, the rear wheel 32 rotates so that the chair 1 moves only in the front-rear direction Df.

  A concave portion 37b that is recessed toward the inner side in the width direction Dh is formed on the outer side surface of the wheel body 37 in the width direction Dh. The concave portion 37b has a substantially circular cross section centered on the central axis O32. The cover member 40 has a shape that can be fitted into the recess 37b. The cover member 40 is held by the wheel body 37 by fitting into the recess 37b.

The front frame 36 extends forward from the support body 38 and is curved outward in the width direction Dh. Accordingly, the front end portion 36f of the front frame 36 is located outside the support body 38 in the width direction Dh. Since the front wheel 31 is disposed below the front end portion 36f of the front frame 36, the pair of rear wheels 32, 32 are located between the pair of front wheels 31, 31 in the width direction Dh. More specifically, the positions of the pair of rear wheels 32, 32 that are in contact with the floor surface F are arranged between the positions of the pair of front wheels 31, 31 that are in contact with the floor surface F in the width direction Dh. Here, “between” the pair of front wheels 31, 31 means that the pair of front wheels 31, 31 approximately coincides with the traveling direction of the pair of front wheels 31, 31 and the traveling direction of the pair of rear wheels 32, 32. In the state where the posture is taken, the portion located on the outermost side in the width direction Dh among the portions contacting the floor surface F of the rear wheel 32 is located on the outermost side in the width direction Dh among the portions contacting the floor surface F of the front wheel 31. It means a state in which it is located inside the width direction Dh rather than the portion that is located.
The support 38 has a cylindrical frame insertion portion 361 into which a base end portion 351 of a first frame 35A of the support frame 35 described later is inserted. The frame insertion portion 361 is formed behind the front wheel 31 and ahead of the rear wheel 32.
The front frame 36 and the support 38 constitute a wheel support portion that supports the wheel bodies 37 of the front wheels 31 and the rear wheels 32.

  As the auxiliary wheel 34, a caster having a known configuration can be used. The auxiliary wheel 34 is connected to the lower surface of the rear end 39r of the rear frame 39 so as to be rotatable about an axis along the vertical direction Dv. The front end 39 f of the rear frame 39 is fixed to the support body 38 with screws or the like, and the rear frame 39 extends rearward from the support body 38. As a result, the auxiliary wheel 34 is connected to the support frame 35 via the rear frame 39.

  As shown in FIGS. 2 and 6, the front frame 36 and the rear frame 39 have a line segment L1 connecting the lower end of the front wheel 31 and the lower end of the auxiliary wheel 34 in the side view as viewed from the width direction Dh. It is adjusted so that it may be arranged above the lower end. Therefore, in the support structure 30, the front wheel 31, the rear wheel 32, and the auxiliary wheel 34 do not contact the flat floor surface F at the same time, and only the front wheel 31 and the rear wheel 32 contact the floor surface F, or the rear Only the wheel 32 and the auxiliary wheel 34 are in contact with the floor surface F.

  The support frame 35 connects the front frame 36 and the support body 38 to the seat 10. The support frame 35 includes a first frame 35A and a second frame (front support portion) 35B.

As shown in FIG. 6, the first frame 35 </ b> A of the support frame 35 includes a base end portion 351, a lower skew portion 352, a curved portion 353, a skew portion 354, and a seat connecting portion 355.
The base end portion 351 is inserted into the frame insertion portion 361. Accordingly, the base end portion 351 is connected to the front frame 36 and the support body 38 behind the front wheel 31 and ahead of the center axis O32 of the rear wheel 32.
The lower skew portion 352 is formed between the base end portion 351 and the skew portion 354, and extends obliquely upward from the base end portion 351 toward the front.
The curved portion 353 is formed continuously with the lower oblique portion 352 and is curved backward toward the upper side.
The oblique portion 354 is formed continuously with the curved portion 353 and extends obliquely upward toward the rear.
The seat coupling portion 355 connects the upper end portions of the skew portion 354 of the first frame 35A provided on both sides in the width direction, and extends substantially along the width direction Dh. The seat connecting portion 355 is connected to the lower surface of the seat plate 12 via a fixing means (not shown) and supports the seat 10.

  The second frame 35 </ b> B is provided between a position spaced in the vertical direction between the second frame 35 </ b> B and the seat 10 in the skew portion 354 and the front end portion of the seat 10. The second frame 35B extends obliquely upward from the skew portion 354 of the first frame 35A provided on both sides in the width direction toward the center side in the width direction Dh. The second frame 35 </ b> B supports the seat 10, with the center portion in the width direction Dh connected to the lower surface of the seat plate 12 via a fixing means (not shown).

  The seating surface 11 of the seat 10 is disposed above the rear wheel 32 by the support frame 35. Further, the pair of rear wheels 32 and 32 are located between both end portions 10e and 10e in the width direction Dh of the seat 10 in the width direction Dh. Further, the pair of rear wheels 32, 32 are arranged so that the entire pair of rear wheels 32, 32 is covered with the seat 10 in plan view.

  The support frame 35, the front frame 36, the support 38, and the rear frame 39 are made of metal such as aluminum, for example.

  Next, operation | movement of the chair 1 which concerns on this embodiment is demonstrated.

  The center of gravity of the chair 1 itself is located behind the central axis O32 of the rear wheel 32. For this reason, before the user sits on the chair 1, the rear wheel 32 and the auxiliary wheel 34 are in contact with the floor surface F in the chair 1, and the front wheel 31 is separated upward from the floor surface F. When the user sits on the seat 10 of the chair 1, the center of gravity moves forward, the front wheel 31 and the rear wheel 32 come into contact with the floor surface F, and the auxiliary wheel 34 moves upward from the floor surface F as shown in FIGS. It will be in a state away from.

  When the user moves forward while sitting on the chair 1, as described above, the user folds the floor 1 with his / her feet facing forward and pulls the chair 1 forward. Here, in the chair 1, since the pair of rear wheels 32, 32 are located between the pair of front wheels 31, 31 in the width direction Dh, the distance between the pair of front wheels 31, 31 in the width direction Dh is set to a pair. It is larger than the rear wheels 32, 32. For this reason, since sufficient space which arrange | positions a user's leg | foot between a pair of front wheels 31 and 31 is ensured, a user's leg | foot is hard to contact the front wheel 31 in said operation | movement. Moreover, since the center axis | shaft O32 is being fixed so that the chair 1 may move only to the front-back direction Df, the rear wheel 32 can perform straight ahead to the front of the chair 1 easily.

  When the user is sitting on the chair 1 and moves in a direction tilted to the side with respect to the front, the user bends the floor 1 with the feet facing the direction, and the chair 1 is bent in that direction. Pull it in that direction while rotating to face. At this time, the user performs an operation of twisting the body around an axis extending vertically from his / her buttocks through the vicinity of the waist. Here, in the chair 1 according to the present embodiment, the central axis O32 of the rear wheel 32 is disposed in front of the rear end portion 10r of the seat 10, and the pair of rear wheels 32 and 32 are entirely seated in a plan view. 10 so as to be covered with the Thereby, since the rear wheel 32 is arrange | positioned near a waist | hip | lumbar part from a user's buttocks, the followable | trackability of the rear wheel 32 with respect to a user's operation | movement mentioned above becomes high. The rear wheel 32 follows the movement of the user, moves so as to rub on the floor surface F, changes its direction together with the seat 10 and the backrest 20, and advances straight toward the foot.

  In addition, since the central axis O32 of the rear wheel 32 is disposed in front of the rear end portion 10r of the seat 10, there is a possibility that the chair 1 is inclined backward and easily falls. However, in the chair 1 according to the present embodiment, since the auxiliary wheel 34 that is the rear support portion 33 is provided behind the rear wheel 32, the auxiliary wheel 34 prevents the chair 1 from falling backward.

  According to the present embodiment, the chair 1 includes a seat 10 having a seating surface 11 facing upward, a backrest 20 provided on the rear end side of the seat 10, and the seat 10 and the backrest 20 with respect to the floor surface F. And a support structure 30 that is movably supported. The support structure 30 includes a front wheel 31 that can be in contact with the floor surface F, a rear wheel 32 that is disposed rearward of the front wheel 31 and is always in contact with the floor surface F, and is rearward of the rear wheel 32. And a rear support portion 33 that can be in contact with the floor surface F. A pair of front wheels 31 and rear wheels 32 are provided apart from each other in the width direction Dh. The central axis O32 of the rear wheel 32 is disposed in front of the rear end portion 10r of the seat 10. A line segment L1 connecting the lower end of the front wheel 31 and the lower end of the rear support portion 33 is disposed above the lower end of the rear wheel 32 in a side view as viewed from the width direction Dh.

  According to the configuration described above, the central axis O32 of the rear wheel 32 is disposed in front of the rear end portion 10r of the seat 10, and therefore the position of the central axis O32 of the rear wheel 32 in the front-rear direction Df is From the buttocks of the user who is sitting on the back, it is close to the vicinity of the waist. Therefore, since the distance between the user's body motion axis and the rear wheel 32 following the motion becomes shorter, the rear wheel 32 can follow the user's motion more easily and the mobility of the chair 1 is improved. be able to. In addition, since the rear support part 33 is arranged behind the rear wheel 32, the rear support part 33 prevents the chair 1 from falling over even when the chair 1 tilts rearward. can do.

  Further, the pair of rear wheels 32, 32 are located between the pair of front wheels 31, 31 in the width direction Dh. For this reason, the space | interval of the width direction Dh of a pair of front wheels 31 and 31 can be made larger than the thing of a pair of rear wheels 32 and 32. FIG. Accordingly, a sufficient space for placing the user's foot between the pair of front wheels 31 and 31 can be secured, so that the front wheel 31 is brought into contact with the foot to be moved when the user moves while sitting on the chair 1. The mobility of the chair 1 can be further improved.

  Further, the rear support portion 33 is an auxiliary wheel 34 that can come into contact with the floor surface F. For this reason, the chair 1 can be moved by the rear wheel 32 and the auxiliary wheel 34 even when the chair 1 is inclined rearward and the rear support portion 33 is in contact with the floor surface F. Therefore, the mobility of the chair 1 can be further improved.

  Further, the center axis O32 of the rear wheel 32 extends substantially along the width direction Dh, and the relative angle between the center axis O32 of the rear wheel 32 and the seat 10 is unchanged. For this reason, the rear wheel 32 rotates so that the chair 1 moves only in the front-rear direction Df. Therefore, while making it easy to move the chair 1 straight, it is possible to perform the orientation when moving in a different direction more reliably. Therefore, the mobility of the chair 1 can be further improved.

  Further, the seat surface 11 is disposed above the rear wheel 32. For this reason, it is possible to make it difficult for the user's arm or clothes sitting on the seat surface 11 to contact the rear wheel 32.

  Further, the rear wheel 32 is located between both end portions 10e and 10e of the seat 10 in the width direction Dh in the width direction Dh. Therefore, since the rear wheel is arranged closer to the waist near the user's buttocks in the width direction, the distance between the user's body movement axis and the rear wheel 32 following the movement. Becomes shorter. For this reason, it becomes easier for the rear wheel 32 to follow the movement of the user, and the mobility of the chair 1 can be further improved.

  Further, the rear wheel 32 is disposed so that the entire rear wheel 32 is covered with the seat 10 in a plan view. For this reason, the rear wheel 32 is disposed directly below the seat 10 on which the user sits. Therefore, since the rear wheel 32 is arranged closer to the waist near the user's buttocks while sitting on the chair 1, the distance between the user's body motion axis and the rear wheel 32 following the motion is Shorter. For this reason, it becomes easier for the rear wheel 32 to follow the movement of the user, and the mobility of the chair 1 can be further improved.

  Further, the radial dimension of the rear wheel 32 is larger than the radial dimension of the front wheel 31. Since the load is more easily applied to the rear wheel 32 than the front wheel 31, the stability of the chair 1 can be improved by making the radial dimension of the rear wheel 32 larger than the radial dimension of the front wheel 31.

Further, the first frame 35A of the support frame 35 is rearward of the front wheel 31 and forward of the center axis O32 of the rear wheel 32, and a base end portion 351 connected to the front frame 36, and obliquely upward toward the rear. An oblique portion 354 that extends, and a seat coupling portion 355 that is formed at the upper end of the oblique portion 354 and is coupled to the seat 10 are provided. In this manner, the skew portion 354 of the support frame 35 extends obliquely upward toward the rear, so that when the user is seated on the seat 10 and tries to move the chair 1 forward, 10 is transmitted to the front frame 36 via the skew portion 354. This component force is applied to the front frame 36 and the support 38 that support the wheel main body 37 of the front wheel 31 and the rear wheel 32 via a frame insertion portion 361 between the front wheel 31 and the center axis O32 of the rear wheel 32. Since it acts from diagonally upward to diagonally downward, the front frame 36 is pressed forward while being pressed downward. Thereby, the mobility of the chair 1 can be improved more.
In addition, the load downward in the vertical direction in a state where the user is seated on the seat 10 becomes a component force that is directed obliquely downward toward the front via the skew portion 354. As a result, the load component downward in the vertical direction is reduced, so that the moment for separating the support frames 35 on both sides in the width direction Dh is reduced.

Further, the first frame 35A is continuous between the base end portion 351 and the skew feeding portion 354, the lower skew feeding portion 352 extending obliquely upward from the base end portion 351 toward the front, and the lower skew feeding portion 352. And a curved portion 353 that curves backward and continues to the skewed portion 354.
In this way, the user sitting on the seat 10 by providing the lower oblique portion 352 extending obliquely upward toward the front and connecting the lower oblique portion 352 and the oblique portion 354 through the curved portion 353. A force that pulls the front frame 36 obliquely forward acts by the vertical load due to. Thereby, the mobility of the chair 1 can be improved more.

  The support frame 35 further includes a second frame 35 </ b> B provided between a position in the oblique portion 354 that is vertically spaced from the seat 10 and a front end portion of the seat 10. Thereby, the seat 10 can be stably supported by the upper end portion of the skew portion 354 and the second frame 35B. Further, the force input to the seat 10 when the chair 1 is moved forward is efficiently transmitted from the front end side of the seat 10 to the skew portion 354 via the second frame 35B. Thereby, the mobility of the chair 1 can be improved more.

  Further, the front frame 36 has a cylindrical frame insertion portion 361 into which the base end portion 351 of the support frame 35 is inserted. With this configuration, when the chair 1 is assembled, the base end portion 351 of the support frame 35 may be inserted into the frame insertion portion 361 of the front frame 36, and the assembling work can be easily performed.

  In addition, a pair of the front wheel 31, the rear wheel 32, the front frame 36, and the support frame 35 are provided at intervals in the width direction of the seat 10. By comprising in this way, the space which can put a user's leg etc. under the seat 10 can be formed.

  In the present embodiment, a pair of the front wheel 31 and the rear wheel 32 are provided apart from each other in the width direction Dh. However, the present invention is not limited to this. It is sufficient that at least one of the front wheel 31 and the rear wheel 32 is provided as a pair spaced apart in the width direction Dh. Further, a pair of front wheels 31 and rear wheels 32 may be provided. For example, a third rear wheel may be further provided between the pair of rear wheels 32, 32.

  Further, the support structure 30 is perpendicular to a common tangent line disposed below the front wheel 31 and the rear wheel 32 among the common tangent lines of the front wheel 31 and the rear wheel 32 in a side view as viewed from the width direction Dh, and the center of gravity of the chair 1 The straight line passing through may be configured to substantially intersect the central axis O32 of the rear wheel 32. In other words, the central axis of the rear wheel 32 that is orthogonal to the common tangent line L2 (shown in FIG. 2 and FIG. 6 that coincides with the floor F) that is disposed below the front wheel 31 and the rear wheel 32 shown in FIGS. The center of gravity of the chair 1 may be arranged on a straight line L3 passing through O32. By comprising in this way, the followable | trackability of the rear wheel 32 to a user's operation | movement can further be improved, and the mobility of the chair 1 can further be improved.

  Although the center axis O32 of the rear wheel 32 is disposed in front of the rear end portion 10r of the seat 10, the back end portion 20r of the backrest 20 is more rearward than the rear end portion 10r of the seat 10. In the case of being arranged, it is only necessary to be arranged in front of at least the rear end portion 20r of the backrest 20. In other words, the center axis O32 of the rear wheel 32 only needs to be disposed forward of the rear end portion 10r of the seat 10 and the rear end portion 20r of the backrest 20 that is disposed rearward.

  Further, although the central axis O32 of the rear wheel 32 extends substantially along the width direction Dh, this may hinder the movement of the chair 1 in the front-rear direction Df. This includes the case where it is tilted with respect to the width direction Dh within a range.

  The positional relationship in the width direction Dh between the pair of front wheels 31 and 31 and the pair of rear wheels 32 and 32 is not limited to the above-described one, and may be an aspect described below. For example, the portion located on the outermost side in the width direction Dh among the portions in contact with the floor surface F of the rear wheel 32 is more than the portion located on the innermost side in the width direction Dh among the portions in contact with the floor surface F of the front wheel 31. It may be located inside the width direction Dh. Further, the inner side surface in the width direction Dh of the rear wheel 32 may be located outside the width direction Dh than the inner side surface in the width direction Dh of the front wheel 31. In this case, the dimension of the front wheel 31 in the width direction Dh is made larger than the dimension of the rear wheel 32 in the width direction Dh, and the outer side surface of the rear wheel 32 in the width direction Dh is outside the width direction Dh of the front wheel 31. You may make it be located inside the width direction Dh rather than the side surface. Further, the portion located on the outermost side in the width direction Dh among the portions in contact with the floor surface F of the rear wheel 32 is wider than the portion located on the outermost side in the width direction Dh among portions in contact with the floor surface F of the front wheel 31. In a state of being located inside the direction Dh, in a portion above the portion of the rear wheel 32 that is in contact with the floor surface F, such as the central portion of the wheel body 37 in the vertical direction Dv or the cover member 40, the width direction Dh The outermost part may be located on the outer side in the width direction Dh than the part located on the outermost side in the width direction Dh among the parts in contact with the floor surface F of the front wheel 31. For example, the outermost portion of the wheel body 37 in the up-down direction Dv and the width direction Dh of the cover member 40 are increased to increase the outermost portion of the wheel body 37 in the up-down direction Dv and the cover member 40 in the width direction Dh. May be located on the outer side in the width direction Dh than the portion located on the outermost side in the width direction Dh among the portions in contact with the floor surface F of the front wheel 31.

  The rear support portion 33 is the auxiliary wheel 34, but is not limited thereto. The rear support portion 33 may not be a wheel as long as it has a configuration capable of coming into contact with the floor surface F.

  The structures of the seat 10 and the backrest 20 are not limited to those described above, and known structures can be appropriately applied. Further, the seat 10 and the backrest 20 may not be directly connected to each other. Although the seat 10 is provided with a pair of armrests 15, the seat 10 may not be provided with an armrest.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Chair 10 Seat 10e End part 10r Rear end part 11 Seat surface 20 Backrest 20r Rear end part 30 Support structure 31 Front wheel 32 Rear wheel 33 Rear part support part 34 Auxiliary wheel 35 Support frame 35A 1st frame 35B 2nd frame (front Support section)
36 Front frame (wheel support)
38 Support body (wheel support part)
351 Base end portion 352 Lower oblique portion 353 Curve portion 354 Oblique portion 355 Seat connecting portion 361 Frame insertion portion Df Front-rear direction Dh Width direction Dv Vertical direction F Floor surface (installation surface)
L1 line segment L2 common tangent line L3 straight line O32 central axis

Claims (14)

A seat having a seating surface facing upward;
A backrest provided on the rear end side of the seat;
A support structure that movably supports the seat and the backrest with respect to an installation surface;
With
The support structure is
A front wheel capable of contacting the installation surface;
A rear wheel disposed behind the front wheel and provided so as to always contact the installation surface;
A rear support part disposed behind the rear wheel and capable of contacting the installation surface;
Have
At least one of the front wheel and the rear wheel is provided as a pair spaced apart in the width direction of the seat,
The center axis of the rear wheel is arranged in front of the rear end of the seat or the back end of the backrest,
In a side view as viewed from the width direction, a line segment connecting the lower end of the front wheel and the lower end of the rear support portion is disposed above the lower end of the rear wheel. The chair according to claim 1,
A pair of the front wheel and the rear wheel are provided apart from each other in the width direction,
The pair of rear wheels are positioned between the pair of front wheels in the width direction. The chair according to claim 1 or 2,
The rear support part is an auxiliary wheel that can contact the installation surface. The chair according to any one of claims 1 to 3,
A center axis of the rear wheel extends substantially along the width direction,
The relative angle between the central axis of the rear wheel and the seat is unchanged. The chair according to any one of claims 1 to 4,
A central axis of the rear wheel is disposed forward of a rear end portion of the seat. The chair according to claim 5,
The seat is disposed above the rear wheel. The chair according to claim 6,
The said rear wheel is located between the both ends of the said width direction of the said seat in the said width direction. A chair according to claim 7,
The said rear wheel is arrange | positioned so that the said whole rear wheel may be covered with the said seat in planar view. A chair according to any one of claims 6 to 8,
In a side view as viewed from the width direction, a straight line passing through the center of gravity of the chair perpendicular to the common tangent line disposed below the front wheel and the rear wheel among the common tangent lines of the front wheel and the rear wheel is the rear wheel. A chair that intersects the central axis of the chair. A chair according to any one of claims 1 to 9,
The radial dimension of the rear wheel is larger than the radial dimension of the front wheel. A chair according to any one of claims 1 to 10,
The support structure is
A wheel support for supporting the front wheel and the rear wheel;
A support frame connecting the wheel support portion and the seat;
With
The support frame is
A proximal end connected to the wheel support portion behind the front wheel and ahead of the rear wheel;
A skewed portion extending obliquely upward toward the rear,
A seat connecting portion formed at an upper end portion of the skew portion and connected to the seat. The chair according to claim 11,
Between the base end portion and the skew portion,
A lower oblique portion extending obliquely upward from the base end portion toward the front;
A curved portion that is formed continuously with the lower skew portion, curves backward and continues to the skew portion,
With a chair. The chair according to claim 11 or 12,
A front support portion provided between a position spaced in the vertical direction between the seat and the front end of the seat in the skew portion;
Further comprising a chair. A chair according to any one of claims 11 to 13,
The wheel support portion includes a cylindrical frame insertion portion into which the base end portion of the support frame is inserted.

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