JPH0952501A - Casters - Google Patents

Abstract

(57) [Summary] [Purpose] Both forward and backward fall can be prevented, the anti-slip projections have high rigidity, and the anti-slip projections have a large supporting force and stability. Provided is a caster for a chair which has a good running property and does not damage the carpet. [Structure] A caster A comprising a main body block 1 and wheels 2 pivotally mounted on the main body block 1, wherein a slip preventing projection 12 is provided.
A space S is provided on both the front and the rear of the body block 1 at the time of movement so as to be integrated with the upper and lower bottom surfaces of the body block 1 and the body block 1 that is smoothly continuous with a gap S between the floor surface F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to casters suitably applied to chairs in offices and the like.

[0002]

2. Description of the Related Art One of the objects to which casters are applied is a chair having casters at the lower ends of its legs. Since such a chair with casters slides on the floor surface with an extremely small resistance, it is extremely convenient when pulling the chair, changing the posture, or moving the chair. It is widely used in the field.

By the way, the type of chair with casters used in offices and the like is increasing, which has five leg blades extending radially. However, there are still many types with front and rear legs and four leg wings that tend to cause tilting of the chair in the front-back direction based on the grounding structure of the legs. In such a chair, when the user moves the center of gravity in the seated state in the front-back direction, after the front leg or the rear leg floats,
The castability of the caster may be bad, and the entire chair may suddenly rotate to a position where the center of gravity exceeds the point of consideration just above the front leg or the rear leg, and the chair and the user are likely to fall forward and backward.

In order to solve such a problem, there are some conventional techniques for preventing a fall by providing a caster body with a protrusion that comes into contact with the ground when a chair is tilted. FIG. 21 shows an example of conventional technology.

The caster is generally composed of a main body pivotally mounted on a chair leg and two wheels pivotally mounted on the main body so as to sandwich the main body. In addition to the main body and the wheels, a thin cover may be attached to the main body so as to cover the wheels. In the conventional technique shown in FIG. 21, a thin plate-like slip prevention projection 312 is attached to a caster on a thin cover 314 on the side of the wheel axle on which the chair and the shaft are attached. It is provided. Before the caster body 301 tilts at an angle where the center of gravity exceeds the speculation point, the slip prevention protrusions 312 contact the floor surface to prevent the chair from tilting further and prevent it from falling.

[0006]

However, the existing casters do not have sufficient countermeasures against falling, and in the above-mentioned conventional technique, the slip prevention projections 312 are provided only on the side of the wheel axles where the axles are pivotally attached to the chair. It is only provided. In general, casters are oriented so that the plane sandwiched by the wheels is parallel to the rolling direction, that is, the direction of movement of the center of gravity, and the axis that pivots the main body to the chair is behind the axis that pivots the wheels to the main body. Have sex. The prior art is based on the idea that it is sufficient to provide the anti-slip projections only in a specific direction with respect to this directivity. However, the caster does not know in which direction the chair will turn during use while being placed in a particular location. That is, the directivity may not function. Directivity cannot work, especially when the casters are stationary.

Looking at the caster of the above-mentioned prior art attached to the lower end of the front leg of the chair, the anti-slip protrusion 312 is shown.
Is on the side where the wheel is axle-mounted with respect to the wheel of the axle, that is, when the slip prevention protrusions 312 are behind the front legs of the chair when viewed from the person who sits on the chair, the front side when viewed from the person who sits on the chair. Cannot fall. Similarly, when the anti-slip protrusion 312 is attached to the lower end of the rear leg of the chair, the anti-slip protrusion 312 is located on the side of the axle wheel that is pivotally attached to the chair. If it is located in front of the rear leg of the chair when viewed from above, it cannot prevent the person from sitting down on the chair from falling backward.

Further, in the above-mentioned prior art, the slip preventing projection 312 is not integrated with the caster body 301,
It is a thin small plate adhered to a thin cover 314. Therefore, the rigidity of the slip prevention protrusions 312 is low, and the load of the eccentric load supported by the slip prevention protrusions 312 is concentrated on the bonding portion between the cover 314 and the slip prevention protrusions 312, so that a large eccentric load cannot be supported.

Further, the portion where the anti-slip projection 312 contacts the ground when the chair is tilted is only the tip of the anti-slip projection 312. Therefore, the slip prevention protrusion 3
If the eccentric load continues to be applied after the grounding of 12 occurs, the entire caster further rotates with the grounded portion as a fulcrum, and therefore the slip prevention protrusion 312 is provided on the perpendicular line from the center of gravity.
The part that touches the ground will not be located, and the chair itself will fall.

Further, even if the caster body 301 is slightly inclined, the slip preventing projection 312 contacts the ground.
Therefore, when used on a carpet, the fibers of the carpet are easily rubbed or entangled during rolling. For this reason, the carpet is easily damaged, and the caster does not run well. The fact that the anti-slip protrusion 312 is close to the line contact in which only the tip portion contacts the floor surface reinforces this disadvantage.

In view of the above-mentioned prior art, the present invention is a chair caster with an anti-slip projection, which can prevent both forward and backward falls, and the rigidity of the anti-slip projection is high, and It is an object of the present invention to provide a product having high stability and good running property when used on a carpet and not damaging the carpet.

[0012]

In order to achieve this object, the present invention is a caster comprising a main body block and wheels pivotally mounted on the main body block, wherein the slip prevention projections are It is characterized in that it is provided at both the front and the rear in the form of being integrated with the main body block, with a gap between it and the floor surface.

Further, the grounding surface of the slip preventing projection has an arcuate or boat bottom type grounding surface.

Further, the slip preventing protrusion and the lower surface of the main body block are smoothly continuous.

A case where the caster of the present invention is applied to a chair will be described.

When the chair is horizontal, the body block does not ground. If the distance between the slip prevention protrusion and the floor surface is set to be almost the same for both the slip prevention protrusion on the side where the chair and the shaft are pivotally attached to the wheel axle and on the opposite side The line connecting the two anti-slip projections is horizontal, and a substantially constant gap is maintained between the anti-slip projections and the floor surface.

When the chair is tilted in either the front-back direction, the body block also rotates about the axle on which the wheels are pivoted at the same angle. When the inclination exceeds a certain angle, either of the slip prevention protrusions on both sides of the main body block will come into contact with the ground. If the anti-slip projections are set to come into contact with the ground before the center of gravity of the chair and its user exceed the speculation point, further tilting of the chair can be prevented. Since the anti-slip projections are provided on both sides of the caster in the moving direction, the chair is prevented from falling when the caster is tilted forward or backward.

Since the anti-slip projections and the main body block are integrated, the load carried by the anti-slip projections is supported by the entire main body block, so that the load of force is not concentrated on a specific portion in the main body block. Therefore, the rigidity of the anti-slip protrusion is improved, and a large unbalanced load can be withstood when the chair is tilted.

If the side section of the slip-preventing projection is arcuate or boat-bottomed, even if an unbalanced load continues to be applied after touching down, as long as the chair does not completely overturn, it will prevent slippage on the vertical line from the center of gravity. Any part of the projection will touch the ground, and the chair will not suddenly lose balance and fall at a certain angle. In addition, the caster does not have a pointed portion that may scrape the carpet when it is used on the carpet because the slip prevention projection and the lower surface of the main body block are smoothly continuous. For this reason, friction between the casters and the carpet and fiber entrainment are reduced in combination with the fact that there is a sufficient gap between the slip prevention protrusion and the floor surface.

It is also preferable to provide a slip stopper made of resin, for example, on the slip prevention protrusion. In this way, the chair can be securely prevented from falling on a floor such as a smooth stone plate or a wooden plate.

As described above, since the casters of the present invention are provided with the slip preventing projections on both sides in the moving direction of the casters, the chair or the like can be prevented from falling when the casters are tilted either forward or backward. You can In addition, since the main body block and the anti-slip projection are integrated, the load of force is not concentrated on a specific part in the main body block, the rigidity of the anti-slip projection is improved, and the anti-slip projection can withstand a large unbalanced load. You can If the side cross sections of both ends of the slip prevention projection are arcuate, the chair will not suddenly lose its balance at the turning of a certain angle, and the slip prevention projection and the lower surface of the main body block will be smooth. When it is continuously used, there is a sufficient gap between the anti-slip protrusion and the floor surface, which reduces friction and fiber entrapment on the carpet when used on the carpet, effectively protecting the carpet. While maintaining high running performance.

That is, the caster of the present invention can prevent both forward and backward falls, the anti-slip projections have high rigidity, the anti-slip projections have large stability, and the carpet can be effectively protected while traveling high. The effect of maintaining performance is achieved.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
~ It demonstrates with reference to FIG.

The caster A shown in FIG. 1 comprises a main body block 1 provided with a slip preventing projection 12 and a wheel 2 pivotally mounted on the main body block 1, and the slip preventing projection 12 is provided.
Is provided so as to be integrally formed on both front and rear surfaces of the main body block 1, and the wheel 2 is at least partly formed from the lower surface of the main body block 1 so that the main body block 1 and the slip prevention projection 12 are separated from the floor surface F. It is characterized in that it is provided so as to project.

The body block 1 is made of hard resin.

The side surface shape of the main body block 1 is shown in FIGS.
As shown in, the upper part in contact with the chair B is narrow, and the lower part in contact with the floor F is wide, and is composed of an upward convex mountain curve and a bottom side between two line segments that sandwich an arched arc. The apex of the curve is slightly behind the bisector of the base. The center of the arched arc is on the extension of the perpendicular line from the apex of the main body block 1, and the hole 21a is formed so as to circumscribe the arched arc. At the center of the curve, this hole 2
It shares the center with 1a and has a slightly larger diameter than the wheel 2.
There is an arc that is almost cut in a part of the bottom surface of the main body block, and this serves as the wheel fitting portion 1a.

The front shape of the main body block 1 is a rectangle with rounded corners, and the internal structure is a resin-molded outer shell and rib skeleton. Only the fitting portion 1a of the wheel is fitted on both sides by the width dimension of the wheel 2, so that the rib skeleton is exposed.

A chimney-shaped boss 11b having a height which is equal to or slightly higher than the apex of the main body block 1 in the vertical direction is provided on the side opposite to the apex of the main body block 1 across the point where the bottom side of the main body block 1 is bisected. The main body block 1 is attached to the lower end of the leg of the chair B so as to be horizontally rotatable and attached by a mounting screw 11 penetrating the hole 11a.

The wheel 2 has a height substantially equal to that of the main body block 1, and the side exposed to the outside of the main body block 1 is a spherical surface having a small curvature so as to be smoothly continuous with the main body block 1. The wheel 2 is pivotally attached to the body block 1 by a shaft 21 that penetrates the hole 21a.

Both skirts of the main body block 1 are slightly recessed, and the front end and the rear end are small arcs which are smoothly continuous with the plane of the bottom surface. In other words, focusing on the groundable surface, it has a sled shape. This portion is the slip prevention protrusion 12 arranged near the floor surface F. That is, the slip-preventing protrusion 12 is provided in the cutout portion 1 provided in the body block 1.
The urethane bumper 12a is integrally formed with b and slightly protrudes from the front and rear wall surfaces and the lower surface of the body block 1.
As shown in FIGS. 7 and 8, specifically, as shown in FIGS. 7 and 8, a small shaft 12b hung from the cutout portion 1b is inserted into a hole 12c formed in a urethane bumper 12a, and a small shaft 12b is formed. It is fixed by melting the tip with heat and caulking. The diameter of the wheel 2 is the main block 1
Is almost equal to the height of the
So that a gap S of about 5 mm is formed between the lower surface of the main body block 1 and the floor surface F, that is, between the slip prevention protrusion 12 and the floor surface F,
As shown in FIG. 9, when the body block 1 is horizontal with the axle 21 as the center of rotation, the angle ψ1 or the angle ψ2 (about 6
It is set so that the slip preventing projections 12 come into contact with the floor surface F for the first time when the slip preventing projections 12 are inclined in the direction of the respective slip preventing projections.

In this way, the caster A of this embodiment is
Since the slip prevention protrusions 12 are provided on both sides in the rolling direction, even if the main body block 1 is inclined forward or backward in the rolling direction of the wheels 2, the wheels 2 slide more than necessary. Is prevented by the anti-slip protrusion 12,
The fall of the chair B can be prevented.

That is, referring to FIG. 10, regarding the caster A of this embodiment attached to the lower end of the front leg of the chair B, the mounting screws 11 for attaching the caster A main body to the chair B are attached to the wheels. It is possible to prevent the person from sitting on the chair B from falling to the front side with respect to the rear side and the front side of the axle 21 that is pivotally attached to the main body. Similarly, in the caster A of this embodiment, which is attached to the lower end of the rear leg of the chair B, the mounting screws 11 for axially mounting the caster A main body on the chair B are more than the axles 21 for axially mounting the wheels on the main body. Whether it is on the rear side or on the front side, it is possible to prevent the person sitting on the chair B from falling to the rear side.

In particular, since the slip-preventing protrusion 12 and the main body block 1 are integrated, the load supported by the slip-preventing protrusion 12 is supported by the main body block 1 as a whole, and the force load is concentrated on a specific portion of the main body block 1. There is nothing to do. Therefore, the rigidity of the slip prevention protrusion 12 is improved, and a large unbalanced load can be endured.

Since the side cross section of the slip preventing projection 12 is arcuate, even if an unbalanced load continues to be applied after the ground contact, unless the chair B is completely overturned, the slip preventing projection 12 is perpendicular to the center of gravity. The chair B does not suddenly lose its balance after a certain angle of rotation as the boundary. In addition, the slip prevention projection 12 and the lower surface of the main body block 1 are smoothly continuous,
The caster A has no sharp-shaped portion that may scratch the carpet when used on the carpet. Therefore, in combination with the fact that there is a sufficient gap S between the slip prevention projection 12 and the floor surface F, friction and fiber entrainment on the carpet by the casters A are reduced.

Further, since the urethane bumper 12a is provided on the slip preventing projection 12, the chair B can be surely prevented from falling even when used on a smooth stone or a wooden floor.

<Second Embodiment> A caster a shown in FIG.
Consists of a body block 101 and wheels 102.

The main body block 101 is made of a hard resin, and has a constant thickness except for the front side, which is slightly thicker on the groundable lower side, and the side surface, which is in contact with the chair B, has a narrow upper portion and a floor surface F.
The lower part in contact with is wide trapezoidal. A hole 111a is formed in the vertical direction from a portion of the chair B located at a position slightly off the center of the trapezoid to the lower end of the leg of the chair B, and the main body block 101 is attached to the leg of the chair B by a mounting screw 111 that penetrates the hole 111a. It is pivotally mounted so that it can rotate horizontally.

Further, a hole 121a is formed horizontally on the opposite side surface of the main body block 101 from the side surface of the main body block 101 by being slightly offset from the hole 111a, and an axle 121 penetrating the hole 121a allows the main body block to pass through. Two wheels 102 are pivotally attached to the main body block 101 so as to sandwich 101.

The lower surfaces of the front end and the rear end of the main body block 101 in the traveling direction of the wheels 102 are formed so as to swell slightly forward and rearward from the main body block 101, and are arranged close to the floor surface F. Thus, the function as the slip prevention projection 112 is given. When viewed from the side, the slip prevention protrusion 112 has an arc shape.

The diameter of the wheel 102 is almost equal to the height of the main body block 101, and the wheel 102 allows the main body block 10 to have the same height.
When 1 is supported in a horizontal state, a gap S of about 7 mm is formed between the lower surface of the main body block 101 and the floor surface F, that is, between the narrowest portion, that is, the slip prevention projection 112 and the floor surface F. The angle ψ3 or the angle ψ4 (about 1
It is set so that the slip prevention projection 112 contacts the floor surface F for the first time when tilted in the direction of each slip prevention projection.

In this way, the caster a of this embodiment is
Since the slip prevention projections 112 are provided on both sides in the rolling direction, even if the main body block 101 tilts forward or backward in the rolling direction of the wheels 102, the wheels 102 slide more than necessary. Anti-slip projection 112
And the fall of the chair B can be prevented.

That is, regarding the caster a of this embodiment attached to the lower end of the front leg of the chair B, the mounting screw 111 for pivotally mounting the caster a main body on the chair B has the axle 121 for axially attaching the wheel to the main body. In addition, it is possible to prevent the person sitting on the chair B from falling to the front side regardless of whether it is on the rear side or the front side. Similarly, with regard to the caster a of the present embodiment attached to the lower end of the rear leg of the chair B, the mounting screw 111 for pivotally mounting the caster a main body on the chair B is better than the axle 121 for pivotally mounting the wheel on the main body. Even if it ’s on the back,
Even when it is on the front side, it is possible to prevent the person sitting on the chair B from falling to the rear side.

Particularly, since the slip prevention projection 112 and the main body block 101 are integrated, the slip prevention projection 1
The load supported by 12 is supported by the entire main body block 101, and the force load is not concentrated on a specific portion of the main body block 101. Therefore, the slip prevention protrusion 1
The rigidity of 12 is improved, and a large unbalanced load can be endured.

Since the side cross section of the slip prevention projection 112 is arcuate, even if an unbalanced load continues to be applied after the ground contact, unless the chair B is completely overturned, the slip prevention projection 112 is perpendicular to the center of gravity. The chair B does not suddenly lose its balance after a certain angle of rotation as the boundary. In addition, the caster a does not have a pointed portion that may scrape the carpet when used on the carpet because the slip prevention protrusion 112 and the lower surface of the main body block 101 are smoothly continuous.
Therefore, in combination with the sufficient clearance S between the slip prevention protrusion and the floor surface F, friction and fiber entrainment on the carpet by the casters a are reduced.

The specific structure and sectional shape of each part are not limited to those in the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, as shown in FIG. 19, it is also preferable to employ a boat bottom slip prevention protrusion 212. By doing so, the same effect as when the arc-shaped slip prevention projection 112 is adopted can be obtained.
Further, the boat-bottom slip prevention projection 212 has a smaller side cross-section curvature, and has a larger tendency to return horizontally when the main body block 101 tilts than the arc-shaped slip prevention projection 112.

Further, as shown in FIG. 20, it is preferable to provide a slip stopper 113 made of resin on the slip preventing projection 212. In this way, the chair B can be surely prevented from falling even when it is used on a smooth stone or a wooden floor.

The casters of the present invention can be applied to furniture other than chairs.

As described above, the caster of the present invention is provided with the slip preventing projections on both sides in the moving direction of the caster, so that the chair or the like can be prevented from falling when the caster is tilted either forward or backward. You can In addition, since the main body block and the anti-slip projection are integrated, the load of force is not concentrated on a specific part in the main body block, the rigidity of the anti-slip projection is improved, and the anti-slip projection can withstand a large unbalanced load. You can Since the side sections of both sides of the slip prevention projection are arcuate, the chair does not suddenly lose its balance at the turning of a certain angle, and the slip prevention projection and the lower surface of the main body block are smoothly continuous. The fact that there is sufficient clearance between the anti-slip protrusions and the floor surface reduces friction and fiber entrapment on the carpet when it is used on the carpet, and it provides high running performance while effectively protecting the carpet. keep.

That is, with the casters of the present invention, both forward and backward falls can be prevented, the rigidity of the anti-slip projections is high, the stability of the anti-slip projections is large, and the carpet is effectively protected while traveling high. The effect of maintaining performance is achieved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a side view showing a state in which the same embodiment is attached to a chair having front legs and rear legs.

FIG. 3 is a side view of the same embodiment.

FIG. 4 is a side view of the body block of the same embodiment.

FIG. 5 is a plan view of the same embodiment.

FIG. 6 is a front view of the same embodiment.

FIG. 7 is a bottom view of the same embodiment.

FIG. 8 is a partially enlarged view of the same embodiment.

FIG. 9 is a side view showing a state where the casters of the embodiment are tilted.

FIG. 10 is a side view showing a state in which the chair to which the caster of the same embodiment is applied is about to fall forward.

FIG. 11 is a perspective view showing a second embodiment of the present invention.

FIG. 12 is a side view showing a state in which the same embodiment is attached to a chair having front legs and rear legs.

FIG. 13 is a side view of the same embodiment.

FIG. 14 is a side view of the body block of the same embodiment.

FIG. 15 is a plan view of the same embodiment.

FIG. 16 is a front view of the same embodiment.

FIG. 17 is a side view showing a state where the casters of the embodiment are tilted.

FIG. 18 is a side view showing a state in which the chair to which the casters of the embodiment are applied is about to fall forward.

FIG. 19 is a side view of a caster having a boat bottom slip prevention protrusion according to another embodiment of the present invention.

FIG. 20 is a side view of a caster having a slip prevention protrusion having a resin slip stopper according to still another embodiment of the present invention.

FIG. 21 is a diagram corresponding to FIG. 3 showing a conventional example.

[Explanation of symbols]

 1, 101 ... Main body block 12, 112 ... Slip prevention projections 13, 113 ... Slip stopper 2, 102 ... Wheels A, a ... Casters F ... Floor surface S ... Gap

Claims (5)

[Claims] 1. A main body block having a slip preventing projection and a wheel pivotally mounted on the main body block, wherein the slip preventing projection is provided on both the front and rear sides in the rolling direction of the main body. A caster characterized by being integrally formed with the block, with a gap provided between the block and the floor. 2. The caster according to claim 1, wherein a side cross section of the slip prevention protrusion has an arc shape. 3. The caster according to claim 1, wherein a side cross section of the slip prevention protrusion is a boat bottom type. 4. The caster according to claim 1, 2 or 3, wherein the slip preventing protrusion and the lower surface of the main body block are smoothly continuous. 5. The caster according to claim 1, 2, 3 or 4, wherein the slip prevention protrusion has a slip stopper made of resin.