US1936409A - Rudder - Google Patents

Description

W. SCHOLZ Nov. 21, 1933.

RUDDER Filed Nov. 5, 1930 Patented Nov. 21, 1933 Scholz, Altona-Flottbek, Germany Application November 5, 1930, Serial No. 493,631, and in Germany February 28, 1930 2 Claims.

My invention relates to an undivided or singlepart rudder for ships which is distinguished from the known fiat plate rudders and the socalled cut-water rudders as hitherto constructed, by the particular property that the body of the rudder is enlarged at the leading edge in close proximity to the rear edge of the rudder post to such an extent that it forms a damming or impeding element for the propeller stream at that point.

The objects and advantages of the invention will be obvious from the following description of an embodiment thereof, read in connection with the accompanying drawing forming a part of this specification and in which Figure l is a diagrammatic lay-out of the rudder constructed according to the present invention, while Figure 2 is a horizontal cross-section of the rudder body and the rudder stern.

Referring to the drawing, it will be seen that the rudder body a is in its general configuration wedge-shaped but, contrary to the so-called stream line rudders, for instance of parabolic form heretofore used, it is provided with a much blunter leading edge disposed in close proximity to the rear edge of the fixed rudder post b, which latter forms a part of the propeller frame.

The advantages aimed at and attained by this construction of the rudder reside mainly in the fact that, upon operating the rudder for careening purposes or the like, the back-water on the pressure side of the rudder will be prevented from flowing to any appreciable extent through the gaps between the gudgeons. For in the rudder constructions as hitherto devised the movemerits of the rudder for careening and similar purposes will cause water to flow with great velocity through the relatively wide gaps whereby the effective low pressure side of the rudder body is greatly impaired.

Second, the idea of enlarging the rudder head about or in the vicinity of the pivotal axis at of the rudder, so.that the thickness or width of the head, as Will be seen in Figure 2, will considerably exceed that of the rudder post I), and the conventional forms of a cut-water head heretofore used, results from the observation that the provision of a water impending or damming structure immediately behind the propeller entails the advantage of creating a higher pressure medium in which the propeller blades operate, and, therefore, ensures a considerable improvement in the propelling efficiency of the propeller.

The particular configuration of the rudder, ac-

crease practically the rate of the resistance offered to the water by the head of the rudder during navigation as compared with the ordinary plate rudders, since the eddies produced by the usual flat or plate rudders due to the rudder arms present in such rudders are entirely avoided owing to the wedge-shaped form of the rudder as shown.

Lastly, by this novel rudder form, the power required for operating the rudder comes close to the low power requirements of a balanced rudder, such as is disclosed for instance in my U. S. Patent No. 1,745,916. The great increase of the rudder thickness and its bluntness at the leading edge to the extent, where this edge forms an actual obstruction and dams up the water ahead of it, has the eifect of throwing the point of maximum rudder pressure considerably forward toward the pivotal rudder axis. Thus the power required for operating the rudder is less than that required for a plate rudder under the same operating conditions, and the length of. the rudder may be reduced accordingly.

Rudders of the type herein shown and described are preferably combined with a narrow rudder post 22 of corresponding out water form as far as this possibly can be done so that the post will afford an efficient transition to the damming edge of the rudder body a but without having the same thickness as the latter as was heretofore frequently the practice. It is, however, a particular feature of the present invention, that existing old flat plate rudder systems with a fixed rudder post, and in which this post cannot be removed, can be reconstructed and remodeled at a very low cost into the improved rudder of the herein described type, since the advantages realized thereby do not reside only in the reduction of work to be imposed upon the steering apparatus, but also in the more eificient steering effect of the rudder itself and in the improved propelling action of the propeller due to the damming action of the rudder body immediately behind the propeller.

It is apparent that in carrying out my invention some changes from the construction herein shown and described may be made. I would therefore have it understood that I do not limit myself thereto, but hold myself at liberty to make such departures therefrom as fairly fall within the true spirit and scope of my invention.

What I claim is:

1. A ships rudder gear, comprising a fixed rudder post and a one-part rudder having a horizontal cross-section of cut-water shape and having its head pivotally attached closely to said tal cross-section of cut-water shape and having its head pivotally attached closely to said post, said rudder head having several times the thickness of the rudder post and having a semi-circular contour for producing an artificial damming up of the water in front of said head to create a high pressure zone in the water immediately ahead of the rudder.

WILLIAM SCHOLZ.

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