JPH07108014A - Chair incorporating castor - Google Patents

Abstract

PURPOSE:To easily move a chair by providing wheels having an outer diameter substantially equal to the height of the base of the chair, and located at opposite side parts of the base, and urging members for urging the wheels so as to locate the treads of the wheels below the lower surface of the base in a no-load condition. CONSTITUTION:Wheels 21, 21 of a castor 2, are arranged on opposite sides of a base 13, having a large diameter substantially equal to the height of the base 13. Further, a coil spring 25 urges the wheels 21 downward in a no-load condition, and accordingly, the lower surface of the base does not make contact with the floor surface although the weight of a chair body is exerted thereto. In this case, the wheels 21, 21 are easily rotated. Meanwhile, when a load is applied to at least one of four corners of a seat, exceeding the resilient force of the coil spring 25 of the caster 2 just therebelow, the wheels 21, 21 of the castor 2 sink toward the base 13 so that the lower surface of the base 13 comes in contact with the floor surface. Accordingly, the operation of the castor 2 at that position is inhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair with casters which is used, for example, as a pair with a study desk.

[0002]

2. Description of the Related Art A school chair used as a pair with a study desk, which has a wooden frame, is relatively heavy for school children, and can be moved when it is stored in the lower limb space of the desk after use. It requires power. It is known that a caster is attached to the wooden frame of such a chair to reduce the force during movement.
In such a caster for a chair, the wooden frame is brought into contact with the floor surface during use to ensure safety so that the chair does not inadvertently move during use and the school children are not injured. That is, the casters are constructed so that when the chair is loaded, the wheel portions thereof are stored in the wooden frame so that the casters operate only when moving.

[0003]

By the way, in the above chair with casters, when the wheel portion of the casters is to be stored in the wooden frame, the wooden frame becomes large by that amount, and there is a problem in design and practical use. On the other hand, the increase in weight becomes a problem. Considering this, when trying to store the wheels in the wooden frame, it is unavoidable to use wheels having small diameters. On the other hand, in the environment where such a chair with casters is used, there are various cases such as a case where the floor surface is a tatami mat, a flooring, and even a carpet. A caster with a small wheel diameter works smoothly on a hard floor such as a flooring, but on a carpeted floor, the wheel becomes difficult to rotate, depending on the length of the carpet's fur. , School children will need some power to move their chairs. The present invention aims to solve such a problem.

[0004]

The present invention takes the following means in order to achieve such an object. That is, the chair with casters according to the present invention is a chair with casters in which casters are attached to a base fixed to the lower ends of the legs of the chair body, and the casters have an outer diameter at least approximately equal to the height of the base. And a wheel positioned on both sides of the base, and a biasing member for biasing the wheel so that the ground contact surface of each wheel is positioned below the lower surface of the base in a no-load state. The bottom surface of the base is in contact with the floor surface when a downward load is applied to the base.

In order to prevent the furniture such as the corresponding desk from being easily scratched, it is preferable that the wheel has a convex surface on its outer surface.

[0006]

With such a structure, the wheels of the caster are located on both sides of the base, so that the outer diameter of the caster is made approximately equal to the height of the base to make it a large diameter.
Even on a soft floor such as a carpet, the wheels do not slip into the floor and the movement is not impaired. Also, the biasing member biases the wheel downwards of the base in the unloaded state, but when a load is applied to the base, the lower surface of the base contacts the floor surface, so the caster operation is prohibited in the seated state. The chair is kept in a closed state, and exhibits the same stability as a normal chair when used, although it is easy to move.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The chair C with casters shown in FIG. 1 is used in combination with a learning desk and comprises a chair body 1 and casters 2. The chair body 1 is made of wood and has a seat 11 and
Legs 12 that support the seat 11, a base 13 fixed to the lower ends of the legs 12, and a backrest 1 that is disposed above and behind the seat 11.
4 and. The leg 12 behind the seat 11 extends above the seat 11 to integrally form a back support rod for supporting the backrest 14. The chair itself excluding the casters 2 may have a configuration widely known in this field, or may have a height of the seat 11 that can be changed. Base 13
Has a notch for attaching the caster 2 near the front and rear ends thereof.

The casters 2 are attached to the left and right bases 13 one each at the front and rear. Each of the casters 2 has a pair of wheels 21, an axle 22, a shaft support 23 that supports the shaft 22, a housing 24 that houses the shaft support 23, and the shaft support 23 that is attached to the lower portion of the housing 24. The coil spring 25 is a biasing member for biasing.

The wheel 21 is made of synthetic resin, and has a circumferential surface 2 serving as a grounding surface on the periphery of a convex disk for weight reduction.
1a is integrally formed with a predetermined width. With such an outer shape, it is possible to prevent the side surfaces 2a of the wheels 21 from scratching each other even if they collide with a desk or the like during movement. A boss portion 26 for fitting and fixing the axle 22 is formed in the inside of the side surface 2a, that is, in the center of the rear surface 2b having a concave shape. As shown in FIG. 3, the boss portion 26 has a ridge 26a corresponding to a groove 22a provided in the vicinity of the tip of the axle 22 therein, and the ridge 26a fits in the groove 22a of the axle 22. By fitting, it can be mounted so as not to fall off the axle 22. Then, the boss portion 26 functions as a substantial bearing. Correspondingly, both ends 2 of the axle 22
2b is formed in a substantially spherical shape so that the wheel 21 can be easily mounted.

The housing 24 has a width equal to the width of the base 13, and is provided with mounting portions 24a for fixing it to the base 13 at the front and rear of its lower end, and the axle 22 is extended on both side walls 24b. An elongate hole 24c for taking out is provided.
The length of the elongated hole 24c is determined according to the elastic force of the coil spring 25 and the position of attachment to the base 13. The coil springs 25 are arranged between the shaft support portion 23 and the upper inner surface of the housing 24 one by one in the front-rear direction of the base 13 with the axle shaft 22 as the center and in the front and rear thereof.
Is urged downward. The urged shaft support portion 23 is located at the lowest position in the housing 24 and supports the axle 22.
Is in contact with the lower edge of the long hole 24c. The axle 22 extends outward from the housing 24 through a long hole 24c, and the length on the outer side is approximately equal to the thickness of the wheel 21, and the wheel 21 is attached to the base 13 when the wheel 21 is attached. It is set so that there will be a gap so that the inside of will not contact.

In the above structure, the caster 2
Is inserted into the cutout portion of the base 13, and the mounting portion 24a of the housing 24 is fixed by screws. Zodiac 11
In a state in which nothing is placed, that is, in a no-load state, the coil spring 25 urges the wheels 21 of the casters 2 downward, and the weight of the chair body 1 is added, but the lower surface of the base 13 is Do not touch the floor. As described above, when the chair body 1 is floated from the floor by the front, rear, left, and right casters 2, the wheels 21 located on the left and right side surfaces 13a of the base 13 easily rotate to easily move the chair body 1. can do.

However, for example, when a load equal to or greater than the elastic force of the coil spring 25 of the caster 2 immediately below is applied to at least one of the four corners of the seat 11,
The wheels 21 of the casters 2 sink to the base 13 side, and the lower surface of the base 13 comes into contact with the floor surface. As a result, only that portion of the caster 2 is prohibited from operating due to the contact between the base 13 and the floor surface, which makes it difficult to move the chair body 1. In other words, even when the seat 11 is seated in a shallow manner such that a load is partially applied, the wheels 21 of the casters 2 are surely sunk, and the movement of the chair body 1 when seating deeply from the shallow seating position is prohibited, It is possible to secure sufficient safety. Further, since each wheel 21 is arranged on the outer side of the side surface 13a of the base 13, even in the case of such a sinking, the sinking operation is less affected. Therefore, as compared with the case where the base 13 is housed in the base 13, the size of the base 13 is less restricted and the outer diameter of the base 13 can be increased. Moreover, by increasing the outer diameter, the movement becomes smooth, and the obstacles on the floor are less likely to obstruct the movement.

When seated, each caster 2 sinks, the entire lower surfaces of the left and right bases 13 contact the floor surface, and the casters 2 cannot move.
Also, if the sinking stroke of the caster 2 is set to about 8 mm with the outer diameter of the wheel 21 set to 50 mm, the caster 2 can be used without feeling the anxiety of sinking deeply when sitting.

The present invention is not limited to the embodiment described above.

Besides, the configuration of each part is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0017]

INDUSTRIAL APPLICABILITY As described in detail above, the present invention makes it possible to increase the outer diameter of a wheel by locating the wheel on the outside of the base. It can be easily moved even on a soft floor. Moreover, since the lower surface of the base comes into contact with the floor surface when a load is applied, it is easy to move, but it is possible to sufficiently secure safety when seated.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention as viewed from below.

FIG. 2 is a side view showing an enlarged main part of the embodiment.

FIG. 3 is a cross-sectional view showing a mounted state of the wheels of the embodiment.

FIG. 4 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 ... Chair body 2 ... Caster 12 ... Legs 13 ... Base 21 ... Wheels 25 ... Coil spring

Claims (3)

[Claims] 1. A chair with casters in which casters are attached to a base fixed to the lower ends of legs of a chair body, wherein the casters have an outer diameter that is at least approximately equal to the height of the base. And a biasing member that biases the wheel so that the grounding surface of each wheel is positioned below the lower surface of the base in a no-load state, and a downward load is applied to the base. A chair with casters characterized in that the bottom surface of the base comes into contact with the floor when added. 2. The chair with casters according to claim 1, wherein the wheel has a convex surface on its outer surface. 3. The chair with casters according to claim 1, wherein the base is made of wood.