JPS6122635Y2 - - Google Patents

Description

[Detailed Description of the Invention] The function of the propeller hub of a model airplane is to effectively and smoothly transmit the rotational force of the power rubber transmitted through the propeller shaft to the rotation of the propeller blades.

Traditionally, such propeller hubs are made of plastic, wood, primarily balsa wood, and sheet metal.
However, the disadvantages of plastic molds are that the molds are expensive, heavy, and if you want to change the diameter of the propeller or the shape of the blades, you need molds of various sizes. Since the tree is a live tree, it is easily manipulated and dampened, and a considerable amount of wood is required to cut a piece of consistent weight. Since it is handmade, it is difficult to make the same one, and it requires skill, so it is not common. Also, from a functional point of view, it is difficult to maintain left-right balance around the propeller shaft. Since the angle of the blade cannot be changed, the pitch is fixed and cannot be changed.
In terms of strength, the disadvantage is that the boundary between the center of the hub and the propeller blade attachment part is prone to breakage. Next, looking at the problem of how to attach the propeller shaft and hub, since the propeller shaft is made of metal, it is a combination of different materials from the wooden hub, and when it is hit, the shaft hole in the hub expands greatly. It's easy to be a fool and don't last long. It is necessary to increase the number of parts to prevent the shaft from coming off by applying adhesive or wrapping paper or cloth to the place where the shaft is fastened, which has the drawback of increasing the labor and weight. . Compared to this kind of wood, metal plates can be produced at a constant weight, the left-right balance around the propeller shaft is constant, and all processing is done by machines, so mass production is possible and productivity is high. . The pitch can also be changed by simply twisting the propeller blade attachment part, and the weather resistance is also constant, allowing it to be fixed after being changed.

As mentioned above, metal plate hubs are superior to wooden hubs in all respects except weight. However, even a metal plate has the disadvantage that in order to attach the propeller shaft, it cannot be fixed securely unless a thick material such as wood is applied to the center of the hub and the propeller shaft is bent through that material as well.

The present invention avoids this by using sheet metal pipes. The propeller hub for model airplanes made of metal plate pipes is new.

To explain the figures, numerals 1 and 1' are propeller hubs, and 2 is a propeller blade. Fig. 1 shows the basic outline of the tip of the model airplane, and Fig. 2 is an enlarged view thereof. However, although the bead 5 inserted between the propeller hub 1' and the bearing 4 (commonly known as a cometal) in FIG. 1 is a washer 6 in FIG. 2, it may be either bead.

FIG. 3 shows the propeller hub 1 of this invention. The propeller hub 1 according to this invention is made of a metal pipe, and the metal is aluminum. The propeller blade mounting portion 3 is formed by flattening both ends of this aluminum pipe. Since the propeller blade attachment parts 3 at both ends make a certain angle with each other, when the propeller blades are fixed there, the propeller blades form an angle with each other and become pitched. Since the pitch propeller hub is an aluminum pipe, it can be easily changed by further twisting the blade attachment part 3.

Since the propeller hub of this invention has the above configuration, the propeller diameter and blade shape can be changed by replacing the propeller blades. It has a big advantage over propellers.

That is, by manufacturing the hub and the propeller blade separately as in the propeller hub according to this invention, one hub can serve as a common component for propeller blades of various sizes and made of various materials. The propeller blades may be made of wood, balsa wood, paper, plastic board, etc.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic outline of the tip of a model airplane, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a perspective view of the propeller hub of this invention. In the figure, reference numbers 1, 1'... propeller hub, 2... propeller blade, 3... blade attachment part, 4...
Cometal, 5... Beads, 6... Watshiya.

Claims (1)

[Scope of utility model registration request] A propeller hub made of metal pipe for a model airplane, characterized in that the propeller blade attachment parts at both ends of the pipe are flattened in a direction that creates an angle with each other.