JPS6123337Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a float made of foamed plastic or foamed rubber.

[Conventional technology]

As a conventional technology for floats used for floating fishing nets, there is one described in Japanese Utility Model Publication No. 154488/1988. This float has a structure in which the surface layer is a hard skin layer that is denser than the inner layer, and the air bubbles are smaller from the surface toward the inside, so the dense surface layer can prevent water from seeping into the inside. This has the advantage of preventing a decrease in buoyancy. Furthermore, since the surface layer is hard, there is also the advantage that wear resistance and pressure resistance can be improved.

[Problem that the invention attempts to solve]

However, since the inner layer is highly foamed and has low strength, the inner peripheral surface of the rope insertion hole is likely to wear out due to contact with the rope inserted into the center rope insertion hole.
When hauling fishing nets using a net-lifting machine, bending stress is concentrated at both ends of the rope insertion hole, so there is a disadvantage that cracks occur at the ends of the rope insertion hole, making it easy to break.

Therefore, the technical challenge of this invention is to eliminate the above-mentioned disadvantages and increase the strength of the float.

[Means for solving problems]

In order to solve the above problems, this invention provides end tubes made of non-foamed synthetic resin at both ends of the rope insertion hole, and gradually increases the thickness of the end tube toward the opening of the rope insertion hole. The wall is thick, and a protrusion is provided on the inner circumferential surface of the outer end of the end tube.

[Effect]

As mentioned above, by providing the end tubes at both ends of the rope insertion hole, it is possible to prevent the inner peripheral surface of the rope insertion hole from being worn out due to contact with the rope, and also to prevent the inner peripheral surface of the rope insertion hole from being worn out due to contact with the rope. Since the stress in is applied to the protrusion, it is possible to prevent cracking or damage at both ends of the rope insertion hole.

〔Example〕

Hereinafter, embodiments of this invention will be described based on the accompanying drawings.

As shown in the figure, an outer shell 2 is formed on the outside of the central core 1, a rope insertion hole 3 is provided in the center of both, and end portions made of non-foamed synthetic resin are provided at both ends of the rope insertion hole 3. A cylinder 4 is provided.

The central core 1 is made of highly foamed material, while the outer shell 2
is made of low foam material. Here, examples of the foaming material include synthetic resins such as vinyl chloride mixed with a foaming agent, and synthetic rubber. For such high foaming material and low foaming material, the same raw material may be used and the mixing ratio of the foaming agent may be changed, or raw materials having different expansion ratios may be used.

When manufacturing such floats, special public
The manufacturing method disclosed in Publication No. 2235 can be adopted. That is, pre-formed end tubes 4 are set on both ends of the core rod, both ends of which are supported by the mold, or both ends of the core rod are covered with non-foamed synthetic resin, while the mold is A low-foaming material is applied to the inner periphery to form an outer layer of the required thickness, and a high-foaming material is filled inside the outer layer, and the low-foaming material and high-foaming material are pre-foamed by applying pressure and heating. It is taken out from the mold and subjected to secondary heating to cause secondary foaming.

In addition, a mold may be used for secondary foaming,
Alternatively, foaming may be performed without using it.

The end tube 4 has a thickness that gradually increases from the inner end facing the center of the central core 1 toward the outer end, and a protrusion 5 is provided on the inner periphery of the outer end.

〔effect〕

As described above, in this invention, the rope insertion hole in the central core, which has a high foaming ratio and is weak in strength, is reinforced by providing unfoamed synthetic resin end tubes at both ends of the rope insertion hole, so that the rope insertion hole is strengthened due to contact with the rope. The end tube can prevent wear on the inner circumferential surface of the rope, and when lifting the net, bending stress is applied to the protrusion on the thick inner circumference of the end tube. It is possible to prevent cracks from occurring or breakage in the parts, and this can have a great effect on improving the strength of the float.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a float according to this invention, and FIG. 2 is a partially cutaway front view of the same. 1... central core, 2... outer shell.

Claims (1)

[Scope of utility model registration request] The central core is made of high foam material and the outer shell is made of low foam material.
In a float with a rope insertion hole formed in the center, end tubes made of non-foamed synthetic resin are provided at both ends of the rope insertion hole, and the end tubes are directed from the inner end facing the center of the central core to the outer end. 1. A float characterized in that the end cylinder is made thicker and has a protrusion on the inner circumferential surface of the outer end of the end cylinder.