US1670997A - Means for steering and propelling ships - Google Patents

Description

May 22, 1928. 1,670,997 J; TUTlN MEANS FOR STEERING AND PRQPBLLING SHIPS Filed. April 5, 1926 Inventor 1m Jam 13y [dad/Z66 Patented May 22, 1928.

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JOHN TUTIN,;OF SUN DERLAND, ENGLAND.

MEANS ron s'rnnnine AND PROPELLING SHIPS.

Application fil ed April,3, 1 9 26, Serial No. ,99, 537, and in Great Britain January 22, 1926.-

It isflknown that; by arranging suitably curved orinclined plates abaft a screw propeller,.the rotation in the streampf water leaving the screw will cause the water to im; pinge n theiplates in s ch a manner a ito; producea propulsive forceor reaction. a This reactionis the .s'uin ofthe forwardcompo; nents of the f pressure on the ,onfe side; and] the suction or defect of pressure on the other side, and it is known that the, suction effect is normally the, greater ,of the two. 1

Several. forms ,of rudder have been proposed in which application; is made of this F or example, it has been pro-1 posed tov give a rudder a twisted shafpe, .so

principle.

that it partakes somewhat of the form of the thread of'a quick screw, theobject being 3 thatin its mean positionsuch a rudder will present a face or faces parallel or approxi mately so, to the, water driven sternward from the screw propeller.

Another deviceconsists informing a cou'n-f ter propeller on the stern post andlas'sociating therewith a shroudedunbalanced rudder.

It=,has also been proposed to, providefa counterpropeller, mounted abaft the ordinary propeller, and adapted to inultibladed be swung about to port. anl starboard angles to divert the flow o'f.,tlie,propulsive jetand thus control steering; Further it ,liasfbeen proposed totattach such a counterpropeller to an ordinary rudden One of the. .difliculties.inadaptinga rudderfor propulsive purpoesby merely twistk ing, inclining, or curv ngthe plate or plates,

is due to the position of the mainpiece, which would serously interfere with; the fiow of wateiyoverthe curved or inclined; portions of the rudder, and so prevent the full jde-f velopment of the; reactionor regenerative eflect.

Myinvention consists of ,a balanced rud den comprising substantially vertical mem bers, which differs essentiallyfrom all other known forms. of rudder such asreferred to,

arranged to port and/or starboard of thein that it is constructed of approximately conventional size and height ofa manipiece,

arms extending ,fore and. aft of said main referred to in the preceding paragraph fi h inter .alia, orercomebyso arrangingpne or more of the rudder plates to port and/or starboard of the mainpiece that there. is a reasonable'clearance between such plate'or ,pla tes and the'mainpiece, the space oifering no material restriction to the fiow of water therethrough, and permitting of the complete oralm'ost complete development of the suction .effect'above referredto.

I balance rudders of the type above described by extending a part or parts of the plating forward past the pivotal axis, on

either the port or starboard side of the mainpiece, or on both sides.

Many. forms of balanced rudder are known. They differ from the ordinary un-- i balanced rudder in that instead of the whole rudder area being abaft the pivotal axis, a

rudder is considerably reduced, since it will be seen that when the rudder is inclined at v portionis arranged forward of the axis. By this means the power required to'operate the movement. The difference inthe inomentsof these forces represents the effort which must 'be exerted toturn the rudder, and it can 0bviously' be made very small. 'The line of action of the resultant of the above forces passes through a point known as the centre of pressure, and obviouslyby balancing the rudder, this point may be brought nearer to stern frame, an ordinary unbalanced rud-' der is usually fitted, supported, at its forsingle or multiple screwward end, on 'gudgeons attached tothe sternpost of the vessel. The presenceof the stern an extension of the rudder forward ofits pivotal axis.

the balancing portions of'the' rudder being mainpiece in such a way asto obtain the proper range of angular movement of the than and need not be greater than an amount sufiicient to permit the rudder to clear the post, however, makes it diflicult'to arrange" In such a case it will beseen that my invention permits of a balancedrudder being fitted where this would oth erwise not be practicable, since it provides for sternpost at the maximum angle of helm. With such an arrangement adequate support of the rudder by pintles or otherwise at intermediate points in its height, in'the ordinary way, is possible.

In cases of ships fitted with an open stern frame, an ordinary balanced rudder is usually titted comprising two flat or tapered portions, one directly forward of the main piece, and the other directly abaft the mainpiece. A balanced rudder constructed ac cording to my invention, on the other hand, may be arranged substantially as described above for a vessel with an apertur stern frame, with the exception that in the present case the balanced portion of the rudder would necessarily be supported at an upper bearing only, or at an upper bearing and a lower bearing only, instead of at intermediate points; also, since the stern post is removed in way of the balanced portion of the rudder, the plates may, if desired be arranged nearer to the centre line of the vessel than in the corresponding arrangement with an aperture stern frame. In no case is a separation contemplated between rudder plates and main piece of the order of that required for a box type of rudder, since it is obvious that a rudder adapted to assist propulsion, must be as close as possible to the vertical centre line of the screw disc.

But in order that the invention may be more readily understood and easily carried into effect it will now be further described with the aid of the accompanying drawings in which one example is diagrammatically illustrated by Fig. 1. Fig. 2 representing a series of sections designated A, B, G, D, E, F, G, H and J to correspond to the lines similarly designated in Fig. 1. Figs. 3 and 4 are elevations, at right angles to one another, of a detail. Figs. 5 and 6 are a diagrammatic end elevation and plan respec tively of a modification.

As shown in Figs. 1 and 2 the rudder comprises three plates 1, 2, 3 supported on arms 4 from a shaft 5. The plate 1 is fiat and directly attached to the three uppermost arms so that it is supported on both sides. A right handed propeller is assumed to be employed, that is to say one which rotates clockwise when viewed from astern the ship, in which case the plate 2 will be secured to the port side of three arms 4 above the axis of the propeller whilst the plate 3 is equivalently secured to the starboard side of three arms 4 below the axis aforesaid. This lower set of six arms 4 associated with the plates 2 and 3 are extended as at 4 forward of the pintles 6 and the rudder post 7 which in Fig. 2 is indicated as displaced to show the angle through which the rudder can be turned, in this case about 42 to each side of the central position.

As will be clear from the various sections in Fig. 2 the plates 2 and 3 are, by their arms 4, carried past the main piece 5 with clearance sutlicient for the purpose already referred to.

It will be apparent from the sections in Fig. 2 that the after edges of the plates 1, 2 and 3 are not in vertical alignment but they obviously may be so if desired. Where there is discontinuation in the fore and after edges of the plates means may be provided found that the centre of pressure acts at a relatively short distance from the axis of the pintles and that its movement can be effected with greater ease.

Although curved plating is preferred, it will be obvious that the invention is not limited to the use thereof and further that a rudder or rudders according to the invention may be used in twin or multiple screw vessels. Figs. 5 and 6 for example illustrate plates 2, 3 which are inclined to the longitudinal axis of the vessel.

What I claim is 1. In a screw propelled ship, the combination with astern post, of pintles aft thereof, curved brackets movable about said pintles and extending both aft and forward thereof beyond the stern post, the curvature of some of said brackets being the reverse of the curvature of the others and oppositely curved plates attached to said arms and likewise extending fore and aft ofthe pintles and stern post, substantially as described.

2. A screw propelled ships rudder com-, prising a main piece, and'substantially vertical members laterally displaced in relation to the main piece, one at least of such members being extended forward of the main piece leaving lateral clearance between it and the'main piece.

3. A screw propelled ships rudder comprising a main piece, and substantially vertical members laterally displaced so as to occupy positions at opposite sides of the main piece, such members being extended forward of the main piece, leaving clearance between them and the main piece.

4. A balanced ships rudder comprising a main piece and plating, adapted to impart a contributory propulsive thrust to the vessel, characterized by the fact that at any horizontal section such plating is laterally displaced on one side only of the main piece.

5. A balanced ship s rudder adapted to impart a contributory propulsive thrust to the Vessel, comprising a. main piece, and, at any horizontal section laterally displaced plating, on one side only of the mainpiece, said rudder being characterized by the fact that at one intermediate section the plating is discontinuous, the upper and lower platday of March, 1926.

JOHN TUTIN.

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