US241124A - Henry d - Google Patents

Description

H. D. DEANE. Perforated Propeller Blade.

No. 241,124. Patented May 10, 1881.

N. PETERS. Fholo'Lithographor, Wilhlngtnn, D. C.

UNITED STATES PATENT OFFICE.

HENRY D.

DEANE, OF BROOKLYN, NEW YORK.

PERFORATED PROPELLER-BLADE.

SPECIFICATION forming part of Letters Patent No. 241,124, dated May 10, 1881. Application filed August 17, 1877. Patented in England March 29, 1878.

To all whom it may concern:

Be it known that I, HENRY DANIEL DEANE, a resident of the city of Brooklyn, Kin gs county, and State of New York, have invented certain new and useful Improvements in Screw-Propellers, of which the following is a specification.

This invention relates to that class of devices for propelling vessels known as screw-propellers and in the present instance it consists in a novel application to the various blades of such propellers of a series of perforations, the nature, use, and practical operation of which will be hereinafter fully set forth and described.

In the drawings, which form an essential part of this specification, Figure 1 is a view in perspective of a screw-propeller in which is fully embodied my invention, and Fig. 2 is a vertical section of a single blade of such a propeller.

The same reference-letters found in the two drawings will locate and pointout corresponding parts.

My invention consists in forming in the body of the various blades of a screw-propeller a series of perforations, which maybe of such size and form, and located therein at such points, as

practice may show to be the most effectual for the purpose.

A B O D represent the blades of a screwpropeller, which are cast in the usual form.

a. designates the series of perforations formed therein when the blades are cast, or by drillin g thereafter. forations is conical, in the form of a truncated cone, or that of a tunnel or funnel shape, as plainly shown in the drawings; but their shape may be modified without materially changing the character of my invention.

It will be seen that as the propeller revolves the wide mouth of the perforations in each blade is presented to the water, a portion of which, as it impinges on the blade and perforations, is,by the peculiar shape of the walls of the perforations, ejected therefrom to the rear of the blades with considerable force, while the blade itself, by the increase of the superficial area of its surface, obtains a greater hold upon the body of water upon which it is acting.

The invention aims to accomplish the following objects: the provision of increase the speed a screw-propeller that shall of the vessel and The form I prefer for these perdecrease the consumption of fuel; and my invention secures the following advantages in securing those desired ends: an increase of the superficies of the propellingsur ace without enlarging the size of the blades. This will be readily understood as being due to the amount of surface gained by reason of the walls of the conical perforations, the direct action thereon by the water naturally increasing the propelling power or action of the blade as it impinges on the water. As the blades revolve, the water that is rapidly ejected through the base of the conical perforations in each blade forms powerful jets or columns of water, which are met by each sueceedin g blade. In fine,this action of the perforations on the water is simply forming what, in the use of the ordinary propeller, would be backwater into a strong current, which is always moving in the reverse way toward and impinging on the various blades of the propeller, thus giving them the increased resistance sought for.

In the use of the common propeller it is a well-settled fact that a vacuum forms behind each of the blades, resulting in decreasing the propelling-power. By the use of my perforated blades all objections of this character are obviated, it being impossible for a vacuum to form. It will also be found that these perforated blades will act as a regulator or governor to the engines, which are quickly checked by reason oftheresistance offered to theblades, and this resistance naturally increases with any increase of the number of revolutions of the propeller; this inasmuch as the friction against the surface of the walls of the various conical perforations becomes more intense and the currents of water ejected from the base of the perforations run with greaterforce against the rapidly-revolving blades. The resistance thus met therefore serves to regulate and control the speed of the engines, which are thus caused to work easily and steadily, preventing unnecessary wear, strain, or breakage, either on wheels or engine.

It is a well-known fact that in the present use of screw-propellers each blade thereof is deprivingits succeeding blade of its gripe upon the water, the blades working, as it were, in foam instead of solid water, this, of course, resulting in a great loss of power. Therefore the eradication of this difliculty was a desideratum long wished for, and it is fully and completely accomplished by the use of my perforated blades. Furthermore, a very considerable saving of fuel will be eifected by the use of the perforated blades, not only by increasing the speed and shortening the voyages of steamers, but by economizing the daily consumption of fuel while so doing. It may be here argued, however, that unless the number of revolutions made by the engines be diminished there cannot be a saving of fuel, for the reason that a certain amount of coal must be consumed for every stroke of the pistons. To increase the speed of the engines, therefore, would neither save fuel nor increase the speed of the vessel. The difficulty lies in lessening the speed of the engines and increasing that of the vessel, such being the only way whereby any permanent advantage can be gained in speed and in economy of fuel. ally true in the use of the solid blades of an ordinary propeller; but the reverse is the case in the use of myimproved blades having conical perforations. For it an enormous weight of backwater be taken out of any wheel the engines are at once free, and can work quicker or be operated with a less pressure of steam, can save fuel, and at the same time be doing the same propelling duty; but if by the simple means of conical perforations in the blades the This is liter- I ordinary backwater be converted into a torrent pouring against the successive blades as they revolve, more steam can be used with advantage, and an increase of speed must necessarily result.

It will be plainly obvious to those skilled in steam navigation that "essels provided with the perforated blades can be much more easily handled when towing or running in a seaway, and if disabled or running under canvas only, the blades of the propeller will offer less re sistance, as the water will pass freely throu gh the perforations. In reversing the movement the small openings at the rear of the blades presented to the water have no effect thereon, and the propeller will operate as well as in ordinary cases.

Having thus fully described my invention, what I claim as new is A screw-propeller the several blades ofwh ieh are provided with a series of perforations, such perforations being in the form ofa cone, a truncated cone, or tunnel or funnel shaped, such perforated propeller-blmles applied and operating as and for the purposes substantially as herein shown and set forth.

HENRY D. DEANE.

Witnesses:

A. L. MUNsoN, E; G. YVARD.

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