JP2000335202A - Caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a wheel to rotate or not to rotate automatically depending on whether or not weight is applied to a caster. SOLUTION: A vertical rod 4 having a fixed frame 3 on its upper end is fitted into a supporting frame 5 slidably in vertical direction as well as rotatably about its axis. The supporting frame 5 holds a pair of wheels 7 on left and right such that they can rotate. A come-off prevention portion 9 is provided at the lower end of the vertical rod 4 to prevent it from coming off the supporting frame 5 upwardly. A compression spring 8 is fitted around the vertical rod 4 between the fixed frame 3 and the supporting frame 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caster, more specifically, when a load is applied, rotation of the caster is automatically stopped by the load to maintain an intended installation position. The present invention relates to a device that enables the caster to rotate automatically when the load is released.

[0002]

2. Description of the Related Art As a caster of this kind, a holder for supporting a wheel is provided with a stopper for artificially contacting or separating from a peripheral surface of the wheel.

According to the above means, when stopping the rotation of the wheel, the stopper is brought into contact with the peripheral surface of the wheel, and the rotation is forcibly stopped by the frictional resistance. Also,
When rotating the wheel, the stopper is separated from the peripheral surface of the wheel to release the frictional resistance between the wheel and the stopper.

However, in this conventional caster, the frictional resistance between the wheel and the stopper is not so large, so that when a heavy weight is applied, the original stop function is impaired. As a result, the wheels may be inadvertently rotated or the wheels may slip depending on the direction in which the load is applied.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention
Invented to solve the problem of this conventional caster, it removes the stopper that is manually activated and deactivated as in the past, and automatically determines whether or not the weight is loaded on the caster. It is an object to make it possible to perform rotation operation and non-operation of wheels.

[0006]

According to the first aspect of the present invention,
A vertical rod with a fixed frame attached to the upper end has a support frame that holds a pair of left and right wheels in a freely rotatable manner,
The vertical rod is fitted so as to be freely slidable and rotatable around its axis, and a lower end of the vertical rod is provided with a detachment preventing member for preventing detachment upward from the support frame,
A compression spring is externally fitted between the fixed frame and the support frame around the vertical rod.

According to the above-described means, first, the caster constructed as described above is fixedly attached to a supporting member for supporting a heavy object by a fixing tool such as a bolt or a screw. used.

When a weight is applied to the support member, the vertical rod slides downward in the support frame against the elastic reaction force of the compression spring due to the weight applied to the support member. Finally, the separation preventing member provided at the lower end of the vertical rod abuts on a mounting surface such as a floor, and a large weight is intensively loaded on the abutting surface. Therefore, the rotation of the wheel is automatically stopped, and the weight applied to the support member is supported by the vertical rod. Conversely, when the weight is released from the support member, the vertical rod slides upward in the support frame due to the elastic repulsive force of the compression spring, and its lower end is separated upward from the mounting surface such as a floor. When the upward movement limit is reached, the detachment prevention member abuts on the lower edge of the support frame, and further upward movement is prevented. As a result, the rotation of the wheel is enabled, and the support member can be freely moved.

Therefore, the present invention has the following effects. Depending on the loading or unloading of the weight on the support member, the turning operation and the deactivating of the wheels can be performed automatically. Therefore, the handling of the caster can be performed much more easily than the conventional means for manually operating and deactivating the stopper. In particular, the greater the weight, the greater the load per unit area between the vertical rod and the mounting surface, such as the floor, so that careless misalignment can be prevented.

[0010] In general, to change the location of a heavy load loaded on the support member, a heavy load is imposed on the caster. However, in the present invention, after the heavy object loaded on the support member is a heavy object and is separately moved by a carry-in / out device, for example, a crane, the support member only needs to be moved. Inevitably, the weight applied to each caster is also significantly reduced, so that the necessity of making the caster large and robust is greatly reduced. Therefore, it is sufficient if the vertical rod is small enough to withstand the vertical load of a heavy object, and it can be provided easily and at low cost.

As in the second aspect of the present invention, it is desirable that the wheel is rotatably supported on a support block fixedly attached to the outer peripheral surface of the support frame. The support block for the wheel can be simply attached to the outer peripheral surface of the support frame by using simple means such as welding. As a result, the mounting of the wheel to the support block is extremely simple, and the cost can be further reduced in the manufacture, and the caster can follow the direction well.

According to the present invention, a thrust bearing is interposed between the upper edge of the support frame and the lower end of the compression spring and between the lower edge of the support frame and the separation preventing member. Is desirable. This is because, even if the support member is heavy, the relative rotation between the vertical rod and the support frame is smooth, and the direction following performance of the caster can be remarkably exhibited.

It is preferable that the washer below the thrust bearing interposed between the lower edge of the support frame and the detachment preventing member is constituted by a detachment preventing member. This is because the production cost can be reduced and the production and processing operations can be simplified effectively.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a caster according to the present invention will be described in detail with reference to an embodiment shown in the drawings.

As shown in FIGS. 4 and 5, the caster 1 according to the present invention comprises a fixed frame 3 made of a flat plate fixed to a lower surface 2A of a support member 2 with a fixing tool B such as a bolt or a screw. As shown in FIGS. 1 to 3, a vertical rod 4 fixedly connected to the center of the lower surface of the fixed frame 3, and a lower part of the vertical rod 4 (in the example shown in FIG. 3), a cylindrical support frame 5 in which is fitted, a support block 6 having a rectangular cross section fixedly attached to the outer peripheral surface of the support frame 5, and rotatably held at both ends of the support block 5. One left and right wheel 7
And the lower surface 3A of the fixed frame 3 on the outer periphery of the vertical rod 4.
And between the upper edge 5A of the support frame 5 and
The compression spring 8 includes a compression helical spring, which is an example, and a pad 9 fixedly attached to the lower end surface of the vertical rod 4 as a member for preventing the vertical rod 4 from being detached.

The support block 6 is welded to the outer peripheral surface of the support frame 5. This is to enable easy and inexpensive manufacture. Shafts 10 protrude outward from both ends of the support block 6, and the wheels 7 are rotatably mounted on the shafts 10 on the shafts.

A thrust bearing 11 is interposed between the lower end 8A of the compression spring 8 and the upper edge 5A of the support frame 5. A thrust bearing 12 is also interposed between the lower edge 5C of the support frame 5 and the pad 9. It is intended to facilitate smooth rotation of the support frame 5 about its axis with respect to the vertical rod 4.

The lower edge 5C of the support frame 5 and the pad 9
In the illustrated example, the thrust bearing 12 interposed between the thrust bearing 12 and the pad 9 has a structure in which the pad 9 also serves as a washer below the thrust bearing 12. This is because the production cost is reduced and the production and processing are simplified.

The diameter d of the pad 9 attached to the lower end surface of the vertical rod 4 is equal to or slightly larger than the diameter D of the support frame 5. The figure shows an example in which the dimensions are set to be slightly larger. This is to prevent the lower end of the vertical rod 4 from detaching upward from the support frame 5.

The diameter d of the pad 9 may be set to be at least larger than the inner diameter of the hole 5B for fitting the vertical rod 4 of the support frame 5.

In FIG. 2, reference numerals 13 and 14 denote covers for covering the gaps formed between the upper and lower washers of the thrust bearings 11 and 12 from above to the sides, thereby preventing dust from entering the inside. ing. This is to keep the sliding of the bearing smooth.

The caster 1 configured as described above is
As shown in FIGS. 4 and 5, the support member 2 is appropriately fixed to the lower surface 2 </ b> A of the support member 2 via the fixing frame 3 with a fixture B such as a nut or a screw.

As shown in FIG. 4, specifically, the support member 2 is formed by horizontally connecting the upper ends of a pair of frame portions 21 having one side 20 of an equilateral triangle parallel to the floor. The vertical frame 23 is provided at the four corners as shown in FIG.
In addition, a mounting table having a horizontal frame 24 connecting the lower ends of the vertical frames 23 to each other and fixing a mounting plate 25 over the upper ends of the vertical frames 23 may be used.

The allowable load of the caster 1 is 6
It is formed at 0 to 175 kg (for 60 kg in the illustrated example). Therefore, when only the support member 2 is carried in and out, the main wheel 7 rotates freely, and its direction can be freely changed by the operation of the thrust bearing 11, so that the main wheel 7 is rolled. Support member 2 is easily
And it can be carried in and out freely.

Next, a method of using the caster 1 will be described. The support member 2, which is a support leg or a mounting table, can normally be freely moved by a caster 1. That is, since one support member 2 weighs 60 kg to less than 175 kg, the vertical rod 4 of the caster 1 always projects upward by the elastic repulsive force of the compression spring 8, that is, the position shown in FIG. Will be retained. Therefore,
The wheels 7 can rotate freely, and the traveling direction can be freely changed via the thrust bearings 11.

When the heavy object W is pulled out to a predetermined location to perform various processing operations or to perform processing on a workpiece, the support member 2 is firstly rolled to a predetermined location. And can be easily carried out. Next, when the support member 2 is set at a predetermined position, the heavy object W is placed on the support member 2 by using a crane or a forklift (not shown) (FIGS. 4 and 5).

More specifically, the support legs and the mounting table will be described in detail. First, an appropriate number of support legs, such as a pair or three, is set so that the horizontal frame portions 22 are parallel to each other. They are juxtaposed at an interval. Then
Various machine tools such as a heavy load W, for example, a milling machine, a drilling machine, and the like on the horizontal frame portion 22 and on the mounting plate 25 in the case of a mounting table,
In addition, the work machine or the workpiece is placed so as to be suspended.

When the heavy object W is placed, the casters 1
Will bear a load that exceeds its allowable load limit. Therefore, as shown in FIG.
Is lowered in the support frame 5 against the elastic repulsive force of the compression spring 8, and finally the pad 9 at its lower end is brought into contact with the floor surface G to support the load of the heavy object W. as a result,
The rotation of the wheels 7 of the caster 1 is completely prevented. Therefore, there is no possibility that the support member 2 is inadvertently displaced, and the heavy object W can be securely installed at a predetermined setting position.

In other words, it is uneconomical to keep the heavy objects W that are not used at all times in the work place, in addition to the work efficiency. Therefore, the floor is stored in another place except when the floor is used, and the open floor space is diverted as another work place, and the floor is intended to be used efficiently. The caster 1 according to the present invention has been developed for this purpose. The caster 1 can easily carry in and out the support member 2 for mounting the heavy object W, and when the heavy object W is once mounted. Therefore, it is possible to automatically and firmly secure the setting position on the floor.

[Brief description of the drawings]

FIG. 1 is an overall front view of a caster according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a front view showing the operation.

FIG. 4 is an explanatory diagram of a use state.

FIG. 5 is an explanatory diagram showing another use state.

[Explanation of symbols]

1 ... caster, 3 ... fixed frame, 4 ... vertical rod,
5 ... support frame, 6 ... support block, 7 ... wheels, 8 ...
Compression spring, 9: detachment prevention member.

Claims (4)

[Claims] 1. A vertical rod having a fixed frame attached to an upper end thereof is slidably fitted up and down and rotatably about an axis thereof on a support frame for rotatably supporting a pair of left and right wheels. At the lower end of the vertical rod, a detachment preventing member for preventing upward detachment from the support frame is provided, and a compression spring is externally fitted between the fixed frame and the support frame around the vertical rod. A caster characterized by the following. 2. The caster according to claim 1, wherein the wheels are rotatably supported on a support block fixedly attached to an outer peripheral surface of the support frame. 3. The caster according to claim 1, wherein a thrust bearing is interposed between the upper edge of the support frame and the lower end of the compression spring and between the lower edge of the support frame and the separation preventing member. 4. The detachment preventing member according to claim 1, wherein the washer below the thrust bearing interposed between the lower edge of the support frame and the detachment preventing member is constituted by the detachment preventing member. Casters