Marine Propeller

Abstract

A water propeller for driving water craft such as an outboard motor boat and having the hub and propeller blades made as an integral unit from a rigid transparent material such as glass to reduce noise when propelling the boat through water.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to propellers and in particular to marine propellers utilized on water craft.

2. Description of the Prior Art

The prior art is abundant with a wide variety of propellers for water craft, which propellers are designed in accordance with engineering requirements into many configurations and sizes. However, the prior art has never recognized or attacked the problem of noise, spray and/or wake caused by a rotating propeller driving a ship through water. That such a problem exists is apparent by merely visiting a waterway used by motor boats, pleasure yachts, etc. Even the occupants and pilot of such watercraft are irritated by the noise emerging from the water churned up by a rotating propeller.

SUMMARY OF THE INVENTION

The present invention is summarized in that a water propeller for a water craft is designed with a central hub rotatable about a central axis and a plurality of spaced blades projecting from the hub in generally radial fashion, with the hub and blades being formed as an integral unit which is made of a rigid transparent material having an affinity for water whereby such unit exhibits noise abatement characteristics when rotated in water.

It is an object of this invention to present a solution to the problem causing noise, spray, and/or wake from a propeller driven through water.

Another object of the present invention is to substantially reduce noise, spray, and/or wake caused by a water propeller as it rotates.

The present invention has another object in that a water craft propeller is made from a substantially rigid transparent material.

This invention has another object in that a water craft propeller is made from a glass material.

It is another object of the present invention to construct the hub and blades of a marine propeller into an integral unit.

A further object of this invention is to adapt a water propeller made of glass for direct mounting onto a drive shaft.

Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view of a marine propeller embodying the present invention; and

FIG. 2 is a cross sectional view taken along the line 2--2 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As is illustrated in FIGS. 1 and 2, the present invention is embodied in a propeller, indicated generally at 10, of the type defined as a marine propeller which is attached to a drive shaft for propelling a seacraft through water. The propeller 10 includes a central hub 12 in the form of a hollow cylinder and a plurality of equally spaced blades 14 projecting radially from the hub 12. While the blades 14 are relatively thin in cross-section, the particular shape of the blades 14 as well as diameter and pitch of the propeller may be varied in accordance with particular design requirements. In addition, the drawing shows a plurality of three blades for the propeller but it is to be understood that the specific number of blades is not a material factor in this invention and any number of blades may be utilized as desired or required. For instance, on light outboard motors a two bladed propeller may be sufficient while on heavy outboard motors a four bladed propeller may be required; of course, the number of blades may also be varied with respect to particular usage with inboard engines.

The propeller hub 12 may be provided with a tapered bore, a non-circular bore or a longitudinal key for attachment directly to a conformingly shaped shaft of a motor or engine (not shown). Alternatively, a mounting bushing 16 with a rubber sleeve 17 thereon may be secured in the propeller hub 12 whereby a plurality of differently bored bushings 16 may be kept in stock to conform to the diameters of conventional shafts. The rubber sleeve 17 reduces vibration that would ordinarily be transmitted to the propeller hub 14 and blades 16.

In accordance with the present invention, the hub 12 and blades 14 are manufactured, as by molding, casting, etc., into an integral unit defining the propeller 10. The integral propeller 10 is made from transparent material, such as clear rigid plastic or glass, having high strength characteristics. In using glass as a material for making the integral propeller 10, I have discovered that usage in water obtained a highly unusual result in that the noise of the water and spray or wake of the water are substantially reduced.

The water disturbance and wake reduction is effected by the glass propeller because glass has an affinity for water similar to the slick, slimy transparent coating found on fishes. For example, a volume of water impelled against a metal plate will splatter in all directions away from such plate; however, the same volume of water impelled with the same force against a glass plate will splatter to a much lesser degree than the splattering against the metal plate. While the exact scientific reason for such an unusual result is not known, I believe that it is associated with an oxygen release from the water.

In addition to its water disturbance abatement characteristic, the integral propeller 10 has the further advantage of substantially reducing the wake or cavitation that accompanies usual marine propellers. During turning, the transparent propeller becomes part of the water and may even be driven into a fishing ground without frightening the fishes.

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Claims

What is claimed is:

1. A water propeller for a water craft comprising a central hub rotatable about a central axis,

a plurality of spaced blades projecting from said hub in generally radial fashion,

said hub and said blades being formed as an integral unit,

said integral unit being made of a rigid transparent glass material having an affinity for water, and

said integral unit exhibiting a water disturbance abatement characteristic during rotation in water resulting in substantial reductions in noise and wake as the integral unit proceeds through water.