JPS58191606A - Lubrication-free elastic caster - Google Patents

Abstract

PURPOSE:To generate a self-lubricating action with a lower friction factor by interposing a bush between slide surfaces made of a synthetic resin in such a manner as to be made of material different from the synthetic resin. CONSTITUTION:A caster comprises a fixed frame 1 and a rotary frame 2 solidly molded with a synthetic resin material separately and a support shaft 3 is provided on the side of the rotary frame 2. A bush 4 is made of metal material or inorganic material such as ceramics and numerous small circular outward projections 5 are extruded only on one side of a doughnut-shaped plate having a circular hole 8 made in the center for insertion of the support shaft 3 by pressing. Then, the plate is slitted 7 properly.

Description

[Detailed Description of the Invention] In order to improve the performance of casters, which are commonly used as transport vehicles or as means of transportation and movement for attaching goods, and to maintain light operation, it is necessary to improve the fixed frame and rotation of the casters. The shaft support configuration between the frames must be thoroughly studied.

Therefore, in this invention, the coefficient of friction between similar materials is high and therefore a lubricant is required in such a state, whereas the friction coefficient between metal materials or inorganic materials such as ceramics and synthetic resin materials is Focusing on the fact that the coefficient is extremely low and self-lubricating effect occurs, the caster lubricant is
i! ii The frame and the rotating frame are made of synthetic resin material, or
Or at least by coating these surface layer parts with a synthetic resin material, a synthetic resin sliding surface is essentially formed, and between these sliding surfaces, there is a metal material or ceramic material that is different from the synthetic resin. A caster has been developed whose first feature is that it is fitted with a bushing made of an inorganic material such as.゛And, the bush employed in this invention has many bulging-shaped protrusions formed on its surface or both front and back surfaces,
The second feature of this invention is that these support the radial load or thrust load equally, and by forming a slit in the bushing, the slit and the protrusion work together to fix the caster. A third feature of the present invention is that the bushing is in elastic contact between the frame and the rotating frame in a freely movable manner.

Furthermore, the present invention is characterized in that the caster can be designed in exactly the same manner based on the above-mentioned technical idea, regardless of whether the spindle of the caster is provided on either side of the fixed frame or rotating frame of the caster.

Next, a practical example of the present invention will be described in detail with reference to the drawings.

First, with reference to FIG. 1, a first embodiment of the caster will be described, which is composed of a fixed frame 1 and a rotating frame 2, each integrally molded from a synthetic resin material, and a support shaft 3 is provided on the movable frame 2 side.

A space 11 for assembly is created on the top surface of the fixed frame 1, and a shaft hole 9 is bored in the center thereof, and a part of the upper side of the shaft hole 9 is expanded over the entire circumference, leaving a step 12 to fill the space. form 10.

On the other hand, a support shaft 3 with a circumferential groove 15 carved in its neck is installed on the upper surface of the rotating frame 2, and a two-pronged support frame 13 is vertically installed at the lower part, and an ijj wheel 28 is installed in the center thereof. Shaft hole 14 for mounting
to be drilled.

When assembling the caster, first place the donut-shaped flat bushing 4 on the solid support shaft 3 on one side of the rotating frame 2, and place the cylindrical bushing 4 in the gap 10 of the fixed frame 1. After mounting on the stepped portion 12,
Insert the support shaft 3 of the rotating frame 2 into the shaft hole 9 of the fixed frame 1.
/ , support shaft 30 circumferential groove 15 in rotating frame 2 and fixed frame I
A horseshoe-shaped stopper 16 is installed between the bottom of the hollow space 11 for K'J3.
The caster can be assembled extremely easily by attaching the wheels 28 to the two-pronged support frame 13 of the rotating frame 2.

These bushings 4 are made of a metal material or an inorganic material such as ceramic. In the doughnut-shaped flat bushing 4, as shown in FIG. A large number of outward protrusions 5 having a small circular shape (having a hemispherical cross-section) are bulged out by press working, and slits 7 are formed only on one side of the perforated donut-shaped plate.

In addition, in the cylindrical bushing 4, as shown in FIGS. By forming a bulging corrugated plate by press working and fitting it into the gap 10 of the fixed frame 1 with both ends of the plate in contact with each other so that it is curved to form a substantially annular or cylindrical shape. A cylindrical bushing 4 having a slit 7 is formed by elastically rolling the ends of the bushing.

Next, referring to FIG. 2, a second embodiment of the caster in which the support shaft 3 is provided on the fixed frame 1 side will be described.

A support shaft 3 is integrally vertically disposed at the center of the lower surface of the fixed frame 1, and a circumferential groove 20 is carved in the neck portion of the support shaft 3.

On the other hand, while drilling a shaft hole 17 in the center of the rotating frame 2,
A part of the shaft hole 17 is expanded over the entire circumference, leaving a step 19 to form a gap 18, and a bifurcated support frame 13 is provided at the bottom.
is vertically installed and the shaft hole 14 is bored.

For the set of casters) γ, a disc-shaped bushing 4 is placed in advance on the bottom of the shaft hole 17 in the rotating frame 2, and a cylindrical bushing 4 is mounted on the stepped portion 19 within the gap 18. Lower surface of fixed frame 1 and rotating frame 2
Four donut-shaped places 2 are engraved facing each other on the two sides of J.
1. A donut-shaped flat bushing 4 is placed in the inside and the fixed frame 1 is attached to the rotating frame 2.

In the upper circumferential wall of the rotating frame 2, a stopper pin 24.24 is inserted from one side wall to a pin hole 23.23 drilled from one side wall to the other side wall in the area where the gap 18 is formed.
Insert it, pass it through the middle 20 of the fixed frame 1, and insert it into the movable frame 2.
The casters are completed by fixing them in the pin holes 23, 23 in the other side wall of the caster and by pivoting the wheels 28 in the two-pronged support frame 13.

These bushings 4 have protrusions 5 and slits 7 similar to those of the first embodiment described in Fill, and the bushings 4 are placed in the donut-shaped four places 21 and 22.
is the doughnut-shaped flat bushing 4 in the first embodiment.
Adopt one that is connected back to back to each other.

In addition, the disc-shaped bushing 4 placed on the bottom of the shaft hole 17 of the rotating frame 2 is attached to the shaft of the support shaft 3, as shown in FIGS. The diameter refers to a disk with the same diameter, for example, a large number of small circular protrusions 5 (with a hemispherical cross section), radially protruding rod-like protrusions 5, or a notched circular disk. Bushes 4 in which the protrusions 5 are concentrically bulged out, each having a slit extending from the periphery to the center may be appropriately selected and used.

The bushing 4 mounted on the step 19 in the cavity 18 is completely similar to that of the first embodiment.

Next, with reference to FIG. 3, a third embodiment of a caster equipped with a shaft support means for both radial and thrust thrust will be described.

By opening a space 11 for assembly on the upper surface of the fixed frame 1, drilling a shaft hole 9 in the center thereof, and penetrating a part of the lower side of the shaft hole 9 over the entire circumference to expand it, lunge 25
The gap 10 is formed by leaving the wall frame 26.

On the other hand, a circular pedestal 27 is formed on the upper surface of the rotating frame 2, and a support shaft 3 with a circumferential groove 15 carved in the neck is planted, and a two-pronged support frame 13 is vertically provided at the bottom. A shaft hole 14 is bored.

When assembling the caster, insert the support shaft 3 of the rotating frame 2 with the bushing 4 interposed on the circular pedestal 27 into the shaft hole 9 of the fixed frame 1, and align it with the circumferential groove 15 of the support shaft 3 in the rotating frame 2. A horse-shaped stopper 16 is inserted between the bottom surfaces of the empty space 11 in the fixed frame 1.
The wheels 2 are placed inside the two-pronged support frame 13 of the rotating frame 2.
8 should be installed.

As shown in FIG. 3(B), the bushing 4 has a shaft hole 8 formed in the center of the circular upper wall surface, and a large number of outward protrusions 5 inflated on each wall surface with the inner edge hanging down and the side wall integrally formed. At the same time, a slit 7 is provided.

In this invention, as seen in each of the embodiments described so far, the mutual support structure between the fixed frame and the rotating frame that constitute the caster is such that the support shaft can be placed on either side of these frames. Depending on how the bushings are formed and how the radial and thrust bearing configurations are set, there will be some differences in the relative combinations and shapes of the bushings.

However, the technical concept of interposing a bushing made of a metal material or an inorganic material such as ceramic and having protrusions and slits on a sliding surface whose surface layer is made of a synthetic resin material is common. ing.

As for the cylindrical bushing adopted in the radial bearing part, the shape of the individual outward protrusions 5 and inward protrusions 6 constituting the waveform shape as shown in FIGS. It is also possible to have a shape, a chevron shape, a W-shape, etc., and these cross-sectional shapes may be bulged in one or two rows within the board width without penetrating in the board width direction. Furthermore, the first
A large number of small circular shapes (having a hemispherical shell cross section) as shown in Figure (c) may be provided.

These protrusions may bulge out only on one side of the plate surface, or may be used by being connected back to back as shown in the donut-shaped pusher 4 in Fig. 2. The protrusion pattern formed by the bulging portion is characterized in that it can be selected in common for both cylindrical bushings and flat bushings.

As described above, in this invention, an elastic bushing made of a metal material or an inorganic material such as ceramic is interposed between the synthetic persimmon fat sliding surfaces of the fixed frame and rotating frame of the caster. Moreover, since the large number of bulging protrusions come into contact with each other in a loose manner, when it is used as a transportation vehicle or a means of transport/movement for attaching articles, it has a cushioning effect when traveling on a floor or road surface. In addition, it has the effect of scattering dust when it is caught in the shaft support, does not require any lubricant, does not generate noise, and can be provided at a low cost. It is suitable for various uses such as chairs, travel bags, etc.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1(a) is a side sectional view of the caster of the first embodiment, and FIG.
- An X-ray cross-sectional view, (C) is a plan view of the donut-shaped flat bushing, (Similarly) is a perspective view of the corrugated bushing before installation, and Fig. 2 (A) is the caster of the second embodiment. Side V
fT view, similarly (b) and (c) are side and bottom views of the rotating frame, similarly) is a side view of the fixed frame, similarly (e)
, (f) and (g) are plan views of disk-shaped bushes, 3rd
Figure (A) is a side sectional view of the caster of the third embodiment, and Figure (B) is a plan view of the bushing. 1... Fixed frame of the caster, 2... Rotating frame as well, 3... Support shaft, 4... Button, 5.6...・Bulging protrusion, 7...Slit. Patent applicant Yasushi Itoga (and 1 other person) αυ

Claims (1)

[Claims] A bushing made of an inorganic material is movably abutted between a radial shaft support and a thrust shaft support in a fixed frame and a rotating frame of a caster, the surface layer of which is made of a synthetic resin material at least. The cross section of each protrusion of the protrusion pattern arranged on at least one of the front and back surfaces, which supports the load evenly, has a bulging shape, and the bushing with the slit is elastically inserted between the radial shaft support and the thrust shaft support. A non-lubricated elastic caster that is characterized by its contact.