US2686490A - Rudder - Google Patents

Description

Aug. 17, 1954 J. R. BENCAL 2,686,490

RUDDER v Filed May 15. 195o 2 sheets-sneer ll :mq-.Q wie.

INVENTOR f-/Jahn R. Benca ATTORNEY Aug. 17, 1954 J. R. BENCAI. 2,686,490

RUDDER Filed May 13, 1950 2 Sheets-Sheet 2 IN VEN TOR.

l Jhn R. Banca@ ATTO N EY Patented Aug. 17, 1954 RUDDER John R. Bencal, Houston, Tex., assignor of onehalf to Howard B. Lambdin, Houston, Tex.

Application May 13, 1950, Serial No. 161,773 7 claims. (ci. 114-166) This invention relates to improvements in steering and propelling devices of all types-of water craft and particularly to craft which are of the screw-propelled type.

Generally with present type rudders and steering apparatus and devices, the purpose thereof is to provide means of altering the vessels course by swinging the rudder in the desired direction. Most of these rudders are ineffectual, however, to provide steering ability when the propeller screws are reversed and it is desired to steer the vessel when backing or running astern. This has been a considerable problem, particularly since the advent of mechanical screw propulsion, in all types of watercraft whether in large seagoing vessels or small harbor craft and pleasure boats and particularly when they are propelled by a single screw.

Furthermore, it is well known in the art that about 25 to 35 percent of the power from the propeller is lost by the thrust of the water away from the screw. This wasted energy tends to rise rapidly to the surface, following a path of least resistance, and this turbulence, which is distinctly noticeable in the wake of vessels while moving through water, represents considerable loss of power by too rapid dissipation of the water or propeller thrust.

Moreover, considerable diculty has been encountered in certain screw-propelled type vessels, particularly ones built of steel, in that free oxygen entrained in the water flow to the propeller and discharged in the propellers thrust while running ahead has a tendency to rise immediately after leaving the propeller blades thereby creating considerable cracking noises and vibrations, which are frequently heard over the propeller, and this oxygen impinges on the steel plates above the propeller aperture and overhang of the vessel. This impinging oxygen sets up a corrosive action on the plating which at times is mistaken for an electrolytic action and considerable sums of money have been expended for the installation of zinc plates and the like to overcome this action.

In the past a number of rudders have been developed and tested for the purpose of providing better steering for vessels and to conserve the maximum energy of the water thrust into hull or propeller thrust. In most instances, however, these improved rudders have had certain disadvantages such as, radical changes had to be made to hull structures, shafting arrangements or steering mechanism to accommodate them or the propeller design would require modification in order to adapt it to the particular rudder. Moreover, some of these rudders are designed to closely conne the propeller and the clearances are so close between the rudder and the tips of the 2 propeller blades that floating debris or particles drawn through this conned or narrow space cause considerable damage to the rudders, propellers, propeller mechanisms and the like and, accordingly, cause considerable damage to and at times disables the vessel. Additionally, the majority of these rudder developments are designed to be positioned in the immediate vicinity of or actually conne the propeller. It is well known to those skilled in the art that when a vessel is proceeding ahead at any rate of speed the thrust or reaction of the water leaving the propeller can only be controlled in the wake back of the propel- 1ers where the full effect of this water thrust should and can be secured. Those rudders which substantially coniine the propellers control and restrict the water flowing to the propeller itself exercise little or no control over the thrust or reaction of the water leaving the propeller.

It has been observed in connection with a majority of conventional rudder designs that considerable expense and manual labor are incident and necessary to eiiect repairs to the rudder, remove the rudder for examination or to repair parts of the vessel around the rudder and, particularly, for making repairs which require removal of propeller shafts and propellers where the particular vessel is not built with a stern post. These costs are excessive when considered over a period of time and presents sizable sums of money and loss of time. Moreover, in cases where the vessels propellers are rotated in opposite directions, that is running astern, the conventional rudders known to the art are ineffective to provide steering means for the vessel, particularly in the case of single screw-propelled vessels.

Accordingly, it is a major object of my invention to overcome the difficulties of conventional rudders and steering means known to the art.

It is an important object of my invention to provide a means of steering a vessel while backing or running astern or running at a relatively slow speed.

It is still a further and important feature of my invention to provide a means of steering a vessel whereby repairs may be made thereto with a minimum of labor and expense, in which elements of the steering means or the `entire unit may be quickly and easily removed, replaced or repaired as desired, in which the propeller and propeller shaft` may be removed for repairs without removing sections of or the steering means, and in which repairs to the vessel about the rudder may be made easily, all of such repairs, replacements of parts and the like being made inexpensively with a minimum of loss of time of the vessel.

A further object of my invention is the provision of a rudder which redirects the water thrust from the propeller downwardly thereby reducing turbulence and converting maximum propeller thrust into hull thrust and minimizing the impinging of free oxygen to steel plates over the propeller. and the overhang of the vessel and, accordingly, providing more eiicient propulsion and reducing or limiting corrosion.

It is a still further object and feature of my invention to provide steering means for vessels in which the flow of water to the propeller is not restricted and the steering means may be spaced from the propeller thereby avoiding close tolerances between the rubber and tips of, the Ipropeller blades and accordingly minimizing damage yto the rudder and propeller by floating debris land the like.

l At the present time many tugs, towboats and other vessels cannot operate with a rudder of the "airfoil` type, which generally comprises vanes having profiles ofgwell rounded forward ends converging .into narrow blades orns 'substantially similar to the profiles of l'airplane wings and, consequently, such vessels do notoperate as economically with other types of lrudder's asis possible with the'airfoil type. In theuse of the airfoil rudder, however, when the vessels speed is reduced to a point where the vessel is -making very litt le 'headway, a single airfoil't'ype rudder ils/practically ineffective due to the lack lof resistance andslipstream theairfoil design provides. Thus a considerable number of vessels continue to operate with old, uneconomical box-type'rudders, which, although insofar as power developnient isconcerned, they do give vadequate steering ability, considerable loss of power is occasioned by their use. Accordingly, it is a further and major object and feature of my invention to provide a rudder which can utilize the airfoil design and which may beA used by tugs, towboats and other vessels of single ormultiple screw typeand in which the vessel may be effectively steered at slow speeds, while backing and, accordingly, thereby increasing the efficiency and maneuverability ofthe vessel.

- I accomplish the above objects by providing steering means which include a single pair of vertical vanes and a single horizontal vane located above the shaft level of the propeller, the steering unit being spaced behind thepropeller andthe van'es being of airfoilpronle if desired. Howeven'other features and'objects and a better understanding of my invention will be obtained f romthe following description of a preferred embodiment thereof and by reference to the Vaccompanyin'g drawings where like character references refer to like parts throughout the several views and where Fig. 1 isa side elevationof the stern of a vessel illustrating a'prefer'red embodiment of'my rudder, partly in section,

Fig. 2 is a back elevation similar to Fig. 1,

Fig. 3 is taken along the line 3-3 of Fig. 1,

Fig. 4 is similar to Fig. 1 but illustrates by arrows the downward now of water from the propeller through my rudder, v

Fig. 5 is taken along the line 5 5 of Fig. 4 and illustrates the `converging or channeling of water thrust fromthe propeller, the unrestricted flow of water to the propeller and the arrows indicating the direction of turn of the stern, and ,Fig 6 is similar to Fig. 5 but illustrates the propeller drawing or channeling .the water through and alongside of the steering device while the vessel vis running astern or backing thereby causing the vessels stern to be drawn in the direction shown by the arrows and thereby providing steering ability while running astern but not restricting the now of water to the propeller.

Referring to the drawings and particularly to Figs. l to Sinclusive, thestern I0 of a vessel having a conventional screw propeller I2 is illustrated. A rudder stock I4 depends from the stern lil and a shoe I6 extends from the lower portion vofthe stern having the shoe gudgeon I8. These elements are conventional on various craft and nofmore description thereof is deemed necessary inasmuch as my rudder may be utilized on any conventional screw-propelled craft.

VVThe 'rudder or steering means is indicated by thenumeral 20 and comprises two substantially vertical and parallel vanes or nns 22 equally spaced on either side `of the center line of the propeller. and, in the case of a single screw, the vanes 2 2 `are equally spaced on opposite sides of the 4center line of the stern. The vanes or fins 22v are secured together by the substantially horizontalconnecting members 24 and the rudder 2li is spaced well back of the propeller l2. A horizontal vaneor nn 26 is positioned between the vertical vanes 22 and is preferablyk located above the shaft level of the propeller l2. Preferably the vane 26 extends the full width of the vanes 22 andas indicated in the drawings it is not necessary that the connecting members 24 extend the full widthof the vertical vanes 22,`although they may, ifdesire'd. The 'hanged coupling 28 secures therudder 28 to the rudder stock i4 and the lower nangedpintlei] is positioned in the shoe gudgeon i8. As illustrated the upper connecting member 2,4 may be bolted or otherwise secured to the rudderstocl` I'll and the flanged pintle 30 maybe boltedor Yotherwise removably secured to the lowerconnecting member 24, the pintle 30 being pivotallyorswivelly retained in the shoe gudgeon i8.. Thusby merely unbolting the flanged connections the entire steering means or rudder may be removed for repairs, replacement of parts and the like. Suitable bearings (not shown), of course, are utilized to provide easy pivoting of the rudder.

VI have found it Vsatisfactory and preferable to utilize vanes or. fins of airfoil prole which have a thickened forward end, the thickened forward end being smoothly and well curved and extending into the converging walls of the Vanes which gradually converge in fine points oredges, The prile of these vanes or fins is comparable to the .profile of airplane Thus the individual members of the ru'dder'ZEl provide a minimum of resistance to the iiow of water from the propeller i2 andoinore efficient operation is obtained. It should be noted, however, that othei` conventional vanes 'or fins maybe utilized in connection with rudder; although, my development makes it possible to utilize the embodiment illustrated in the drawings.

,In operation as the vessel is moving ahead, as seen ,in'Fig 4, water flows unrestricted to the propeller and the water thrust from the propeller is'd'ir'ected or channeled downwardly by the rudde'nparticularly by the horizontal vane member, whereby the sudden boiling up Yoi' water in the vessels wake is substantially eliminated.,` thus transferring more propeller thrust to hull thrust and, consequently, providing a more efiicient action of the propeller.

.As illustrated in Fig. 5 positive steering and maneuverability is provided for the vessel when running at extremely vslow speeds and as indicated the water thrust from the propeller tends to converge between the vertical vanes, as well as pass along the outside thereof, and the converging of the water and the reaction of the water thrust provides positive steering ability as well as conserving the power of the normally wasted water thrust. As seen in Fig. 5 the rudder has been turned at about 35 degrees and the stern of the vessel is moving in the direction of the arrow.

In running astern or backing the vessel, as illustrated in Fig. 6, water is drawn between the vanes, as well as along side thereof, in an effort to displace the water demand by the propeller and the drawing of the water between the vanes set at the given angle causes the vessels stern to be drawn in a direction shown by the arrow and, accordingly, positive steering ability is provided while the vessel is running astern.

It is manifest from the above description that the flow of water to the propeller is not restricted in the manner of those rudders which encircle the propeller and provide close clearances between the tips of the propeller blades and the inner surface of the rudder. Moreover, the rudder guides the water thrust or reaction of the screw propellers thrust and accordingly utilizes the normally wasted energy occurring when the water boils up to the surface immediately by converging this thrust and directing the water downwardly after it leaves the propeller. I have found that by guiding and channeling the water thrust between the vanes of my rudder the water will not rise to the surface as rapidly as has been the case in conventional types of rudders or steering devices. Moreover, it seems manifest that floating debris and the like will not foul the propeller and the rudder as would be the case in rudders which are spaced closely about the propeller.

It seems manifest that my rudder may be adapted to any type of vessel in operation with any number of screw-propellers without requiring any structural or mechanical changes to the vessel, its machinery or propellers.

Accordingly, my invention is of wide application and use and while the drawings and description illustrated preferred embodiments thereof, I desire to be limited only to the spirit of the invention as defined in the following claims.

I claim:

1. A steering and propelling device for a vessel having at least one screw propeller comprising, a single pair of spaced vertical vanes disposed in substantially parallel planes and spaced behind and on opposite sides of the center line of the propeller for converging thrust of the propeller, a single horizontal vane extending between and secured to such vertical vanes, such horizontal vane being positioned substantially above the axis of the propeller for channeling the thrust of the propeller downwardly, and means pivotally securing the device as a unit to the stern of the vessel whereby the converged and downwardly channeled thrust of the propeller provides steerability at all speeds and in all directions and increased hull thrust.

2. The steering and propelling device of claim 1 where the vanes have well rounded forward edges and have sides converging smoothly from such forward edges into ne trailing edges.

3. A multi-vane steering and propelling device for a vessel having at least one screw propeller comprising, a single pair of vertical vanes disposed in spaced and parallel relationship on opposite sides of the center line of the propeller, said vanes being spaced behind such propeller, a single additional vane disposed normally of and extending between such vertical vanes and spaced above the axis of the propeller, and connecting members secured to upper and lower portions of such vertical vanes pivotally securing the device as a unit to the stern of the vessel whereby water flowing through and around such device is horizontally directed and water flowing through the device is channeled downwardly thereby providing steerability at all speeds and in all directions and increased hull thrust.

4. The multi-vaned steering and propelling device of claim 8 where the vanes have well rounded forward edges and have sides converging smoothly from such forward edges into fine trailing edges.

5. In a boat of the screw propeller type, the

combination with a hull having a screw propeller of a mUlti-vaned rudder comprising, a single pair of vertical vanes positioned in spaced parallelism to one another and a vertical plane extending through the propeller axis, said vanes being spaced behind such propeller, a single horizontal vane disposed and extending between such vertical vanes and spaced above the axis of the propeiler for :directing thrust of the propeller downwardly, and substantially horizontal connecting members secured to upper and lower portions of such vertical vanes pivotally securing the rudder to the hull rearwardly of the propeller whereby the thrust of the propeller is converged through the rudder thereby providing steerability at all speeds and in all directions and maximum hull thrust.

6. The combination of claim 5 where the vanes have well rounded forward edges and have sides converging smoothly from such forward edges into iine trailing edges.

7. In a boat of the screw propeller type, the combination with a hull having a screw propeller, a rudder stock and a shoe gudgeon, of a multivaned rudder comprising, a pair of vertical vanes disposed in substantially parallel planes and spaced behind the propeller and on opposite sides of the center line of the propeller for converging thrust of the propeller, a horizontal vane extending between and secured at each end tc said vertical vanes, said horizontal vane disposed substantially above the aXis of the propeller for channeling the thrust of the propeller downwardly, top and bottom connecting members secured to the top and bottom of each vertical vane, means on the top connecting member securing the rudder to the rudder stock of the vessel, and means on the lower connecting member pivotally and removably connecting the rudder to the shoe gudgeon of the vessel.

References Cited in the i'lle of this patent UNITED STATES PATENTS Number Name Date 132,991 Thomas Nov. 12, 1872 1,661,114 Flettner Feb. 28, 1928 FOREIGN PATENTS Number Country Date 6,278 Great Britain Apr. 29, 1887 401,821 Germany Sept. 9, 1924 404,841 Germany Oct. 25, 1924 411,564 Germany Mar. 28, 1925

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