JPH0225801B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention ensures smooth rotational movement of the caster under load, prevents wear and tear on the caster bearing, and prevents the rotation of the constituent wheels when not under load. This invention relates to a caster that is designed to prevent rolling as much as possible.

However, in the past, this kind of casters were
In order to improve its load characteristics, an attempt was made to strengthen the bearings of the constituent wheels as much as possible. However, in order to strengthen the load characteristics of such bearing parts, it is required that the bearing parts or the constituent wheels be made of metal material provided by die-casting, etc., which inevitably increases the manufacturing cost. This results in an increase in the price of the caster, increases the weight of the caster itself, and often increases the rotational frictional resistance in the bearing part.

Also, in view of the inconvenience in such a caster,
The provided casters are lightweight and have low rotational frictional resistance in their bearings, but they are said to have poor load-bearing capabilities, and often suffer damage to the bearings, especially damage to the shaft due to bending of the shaft. causing wear and deterioration accidents,
At the same time, due to the bending of the shaft, the smooth rolling of the constituent wheels was hindered.

The caster according to the present invention has been specially devised in view of the inconveniences in the prior art, and has the following features:
It has a lightweight and inexpensive caster structure with excellent load-bearing properties, and at the same time promises smooth rolling of the constituent wheels and effective prevention of wear on the bearings. Based on the point that the gap between the constituent wheels is gradually narrowed in the direction in which the width of the gap between the constituent wheels is gradually reduced, the following specific embodiments and considerable design changes accompanying these embodiments are planned.

Hereinafter, a typical embodiment of the caster according to the present invention will be described with reference to the attached drawings. Reference numeral 1 denotes a shaft rod of the caster, and constituent wheels 2, 2 are rotatably supported on both sides of the shaft rod 1. Moreover, the mounting shaft 4 of the caster is integrally provided with the bearing 3 of the shaft rod 1.

Therefore, the mounting shaft 4 on the caster
is located on the side of the shaft rod 1, that is, in the forward direction of the component wheel 2, and is installed upright from the bearing 3, and except when the component wheel 2 rotates due to reversal operation, the component wheel 2 is always kept in advance. It functioned to position the vehicle in a predetermined direction of advance.

Next, the shaft rod 1 of the component ring 2 and bearing 3 in the description
Various mounting structures are planned for the mounting structure as shown in the example shown in the figure, and an example in which the component wheel 2 and the bearing 3 are made of plastic material is particularly planned. Considerable design changes were planned.

The mutual spacing between the component wheels 2, 2 is gradually reduced in the direction in which the load is applied to such a caster, that is, in the forward direction of the caster and toward the bottom of the caster. , the constituent wheels 2, 2 are pivotally supported on the shaft rod 1, and the mutual opening angle of the constituent wheels 2, 2 is usually set relative to the parallel base line of both wheels.
It is appropriately determined within the range of 0.5 to 10 degrees.

This opening angle is a basic opening angle determined based on the purpose of use of the caster, especially the expected additional load in the cabinet, office equipment, medical equipment, furniture, etc. in which the caster is installed. .

Basically, the opening angle is such that it gradually widens from the forward direction of the caster toward the rear side.
That is, in the planar structure of the pair of component wheels 2, 2, the mounting shaft 4 is set upright, and the width is gradually widened from the forward direction toward the rear side, and the width gradually increases as the caster moves forward. With the applied load, the forward direction ends of the component wheels 2, which have been reduced in width, are expanded, and at the maximum load position, the component wheels 2, 2 are expanded.
The basic case is that they are configured so that they are completely parallel to each other.

Of course, it was also planned to create a parallel state before and after the maximum load position, without creating a parallel state at the maximum load position, and it was also planned to create a parallel state before and after this position, and the opening angle and the angle that corresponded to the purpose of use of the caster The material, bearing configuration, etc. are taken into consideration.

In addition, for casters used for beds and other items that are not primarily intended for movement, and that do not receive much load in the forward direction during movement, It was planned that the design would be such that the opening angle between the component rings 2 and 2 would be gradually reduced in width.

Next, the constituent wheels 2, 2 are moved in the direction of a vector determined quantitatively by the magnitude of the respective additional loads directed in the forward direction of the caster and in the lower direction to which the load is applied. It was planned that the opening angle would be gradually reduced in width.

Since the caster according to the present invention has such a characteristic configuration, it is possible to expect specific effects on the above-mentioned characteristics, and the configuration of the caster is particularly effective when a load is applied. The wheels are generally parallel to each other to ensure smooth rolling with little sliding resistance on the caster.

As shown in Figure 1, the conventional caster has both wheels in a parallel state in the absence of any additional load, and when a load is applied in the direction of the arrow. In this case, both wheels begin to open as shown by the solid lines, and smooth rotation of the two wheels during rolling of the caster is obstructed. In particular, in such a configuration, the shaft rod, the bearing, and the shaft support portions of both wheels are not fitted in parallel to each other, but the shaft rod is necessarily pressed against the bearing surface. This causes abrasion and damage to the bearing surface, causing a situation in which the smooth rolling of the caster is obstructed within a relatively short period of time. In addition, when the caster is used under such a pressure-contact condition, the abrasion resistance is large, and particularly smooth drive of the caster is hindered.

Next, when both wheels are expanded as a load is applied, since this expansion is directed in the forward direction, the wheels themselves function as a stopper, allowing smooth caster rotation. This similarly inhibits movement.

The caster according to the present invention was specially devised in view of the inconveniences in the conventional model, and before a load is applied, the constituent wheels are narrowed toward the front side. This component wheel itself functions as a stopper, and when a load is applied, the component wheels are parallel to each other, ensuring smooth rolling of the component wheels and bite of the shaft rod. This eliminates all concerns about wear and tear.

In particular, the caster according to the present invention has the characteristic structure described above, which eliminates seizure of the bearing part and other disadvantages, and has wear-resistant properties.
This makes it possible to effectively use plastic materials that have relatively poor heat resistance properties, and particularly makes it possible to mass produce lightweight and inexpensive casters.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the constituent wheels of a conventional caster, Fig. 2 is a plan view showing the constituent wheels of the caster according to the present invention in an unloaded state, and Fig. 3 is a plan view of the constituent wheels in the same loaded state. Partial plan view, No. 4
The figure is a partially cutaway front view showing one embodiment of the caster, FIG. 5 is a sectional view of the same side, and FIGS. 6 and 7 are partially cutaway front views showing other embodiments. In the figure, 1... shaft rod, 2... constituent wheels, 3... bearings, and 4... mounting shafts are shown.

Claims (1)

[Scope of Claims] 1. A bearing 3 that supports a shaft rod 1 on which two or more component rings 2, 2 are pivotally supported, and between the shaft support components 2, 2 in this bearing 3, and A caster consisting of a mounting shaft 4 which is positioned laterally from the shaft rod 1 and supported vertically, and which is always positioned at the front of the movement by rotating as the caster moves with the mounting shaft 4 as a fulcrum. the component wheels 2, 2 toward the direction of the mounting shaft 4 that is
A caster characterized in that the spacing between the wheels is gradually reduced, and the shaft rod 1 is curved and supported at right angles to the constituent wheels 2.