US3001502A - Variable area rudder - Google Patents

Description

Sept. 26, 1961 N. D. STOKER 3,001,592

VARIABLE AREA RUDDER Filed Jan. 14, 1960 2 Sheets-Sheet l A's/s an 0. Szoler' M ,W; M21575.-

3,001,502 VARIABLE AREA RUDDER Nelson D. Stoker, 416 Sheridan Road, Keuilworth, Ill. Filed Jan. 14, 1960, Ser. No. 2,412 11 Claims. (Cl. 114-167) This invention relates to a rudder, and more particularly to a rudder whose area may be automatically adjusted in accordance with the speed of a boat, plane or other device controlled thereby to provide effective steer-' ing characteristics throughout the speed range of the vehicle or device.

Heretofore, rudder steered craft, and particularly craft capable of traveling at relatively high speeds, have had undesirable operating characteristics, in that a small rud der area has been required to compensate for the increased effect of the fluid medium onthe steering surfaces at the higher speeds, while this small rudder area has been inad equate for control at lower speeds. The range of speeds available with power propelled craft makes an acceptable compromise in rudder area impracticable, since such an increase in rudder size is dangerous at high speeds and relatively ineflective at low speeds. Although a rudder affording detent controlled adjustment of its action at a predetermined high speed level has been devised, such a rudder is also an unsatisfactory compromise and is both complex and difiicult to adjust and control.

The present invention resolves these problems by means of a rudder consisting essentially of rudder sections pivoted together about a horizontal axis and in parallel planes, with one of the sections being provided with vanes which, at higher speeds, lift it into a folded position with respect to the other section to decrease the effective area of-the rudder. As a result, the steering surface can be.

lifting action of the ambient medium on the vanes of the pivoted section. The vane, or vanes, thus assume a position -parallel to the propeller slip stream, or at a slight inclination such as to prevent vibration at relatively high speeds while exposing a relatively large vane area at lower speeds to afiord the said lifting action, and the sections may be 'providedwith slot and pin means for guiding and limiting their relative movement.

Accordingly, it is an object of the present invention to provide an adjustable rudder efiective to steer craft in water or air throughout a wide range of operational speeds. A

Another object of the invention is to provide a rudder as described which afiords safety and efliciency of control at high speeds and low speeds, as well as intermediatespeeds, in a completely automatic manner.

' Another object of the invention is to provide a rudder whose area .is automatically variable and which is simple, efiicient and foolproof.

Another object of the invention is to provide a rudder of multiple and, overlappingelements whose relative positions arecontrolled, by the weight of the elements or otherwise, in accordance with the speed at which the rudder is moved through an ambient medium.

- Another object of the invention is to provide a rudder having overlapping plates horizontally pivoted to vary the area of the rudder by raising or lowering one of the plates. Another object of the invention is to provide a rudder F ice as described having a section whose position is varied with respect to another section by means of a vane movable toward alignment with the slip stream as speeds increase.

Another object of the invention is to provide a vane or lift means for the rudder as described which is effective to reduce cavitation at high speeds.

Another object of the invention is to provide a multiple section rudder as described'having means for guiding and limiting the relative movement of the sections.

Yet another object of the invention is to provide a rudder having maximum efliciency at all speeds without any need for thought or effort on the part of the operator.

Other objects and advantages of the invention will become apparent as the description proceeds in accordance with the drawings in which:

On the drawing:

FIGURE 1 is a side elevational view of a rudder according tothe invention in combination with a power propelled boat;

FIGURE 2 is an enlarged side elevational view of a rudder according to the invention, and showing the low speed position thereof in dot-and-dash;

FIGURE 3 is a horizontal sectional view taken along the line III--III of FIGURE 2;

FIGURE 4 is a front end view of the structure shown in FIGURE 2;

FIGURE 5 is a side elevational view of another embodiment of the rudder of the invention in combination with a power propelled boat; FIGURE 6 is an enlarged side elevational view of the rudder shown in FIGURE 5, with the low' speed position boat 11 powered by a propeller 14. Although the rudder is thus shown in combination with a beat, it will be understood that it may also be used to great advantage with other vehicles and devices which are rudder steered, including aircraft.

The rudder 10includesa rudder section 12 fixedly secured to a steering post 15 for pivotal movement about a vertical axis, a self-adjusting rudder section 16 horizontally pivotedfor coplanar movement with the rudder section 12 around a pivot point or lug 18, and a vane structure 20 secured to the rudder section 16 for automatically varying the position of the section 16 with respect to the section 12 in accordance with the speed of the boat 11.

The rudder section 12 has an area designed as adequate, proper and safe for controlling the boat 11 at cruising speeds or relatively high speeds, in accordance with the understanding of those skilled in the art. This area is generally inadequate to control the boat properly at relatively low speeds, and in fact, boats designed to travel at high speeds are virtually uncontrollable at low speeds, such as 5 miles per hour, due to the described relatively small rudder area in proportion to the hull.

The rudder section 16 has a configuration complemen tary to that of the rudder section 12, and in the embodiment shown is formed of plates 22 and 24 secured by peripherally spaced studs or rivets 26, 28, 30 and 32 in parallel, spaced apart relationship such as to fold in tion shown in FIGURE 2, is in substantial registration with the section 12 with the rivets 26 through 32 being disposed in peripheral alignment with the rudder section 12, the plates 22 and 24 preferably being cut away adjacent their forward portions to accommodate the socket portion 34 of the rudder section 12, as shown by reference numeral 35. In the described uppermost position, the sections 12 and 16 have a projected area, preferably corresponding to that of the section 12 alone.

The vane'structure 20 onthe rudder section 16 is formed to elevate the said section 16 from the low speed position shown in dot-and-dash in FIGURE 2 to the high speed position shown in solid line, in FIGURE 2, and is aligned in "a position approaching a parallel relation with the slip stream from the propeller 14, in the high speed position, or preferably at a slight upward inclination toward the front of the rudder so as to maintain a constant lifting action on the section 16 and simultaneously to eliminate vibration. The vane structure 20 is shown as being formed of individual vanes 36 and 38 each having inner downwardly turned flanges such as the flange 40 for the vane 38 secured by rivets or the like 42 and 44 to the respective plates 22 and 24. It will be appreciated that the configuration of the vane structure 20 may be varied in accordancewith variations in the type of craft with which the rudder is used and with the complexity of the keel design or the like, the structure shown having a substantially ovoid, planar configuration with a reduced width at the front portions thereof and leading edges '46 and 48 tapered rearwardly so that the vane may bite easily into the water. preferably has trailing edges 50 and 52 which are inclined forwardly for hydrodynamic purposes,'as will be appreciated by those skilled in the art.

Although the vane structure 20 is shown as located adjacent the bottom of the rudder section 16, it may also be aligned in other positions, such as to cooperate with the pivot 18 to afford an effective lifting action.

The pivot 18 desirably is located at the front bottom corner of the rudder section 12, such that the rudder section 16 may have a lowermost position as shown in dotand-clash in FIGURE 2. In order to define the uppermost and lowermost positions shown in solid line and dot-anddash respectively, arcuate slots such as the slot 56 may be formed in the plates 22 and 24 to receive a guide pin 58 having heads 60 and disposed at a suitable radius from the pin 18. The envelope afforded by the plates 22 and 24 may move upwardly without interference around the rudder section 12 as a result of the absence of rivets such as the rivets 26 through 32, to the solid line position, and the pin 58 may coact with the lower ends of slots 56 to afford a stop at the said uppermost position. Likewise, the upper ends of the slots 56, as shown in dotted line in FIGURE 2, serve as a stop to prevent excessive downward movement and forward movement of the section 16.

With the section 16 in its lowermost position, the bottom edge 62 of the section 16 becomes the front edge thereof, with the vanes 36 and 38 disposed at an oblique angle with respect to the slip stream from the propeller 14. Increases in the speed of the boat, however, act upon these surfaces to elevate the section 16 to its uppermost position, as described, and also vary the angular relation of the section 16 to the section 12 in accordance with the speed of the boat, automatically and without any necessity for human intervention. Thereby, accidents caused by errors in judgment on the correct amount of rudder area are eliminated.

As hereinabove indicated, the pivot point 18 is preferably located at the lower front portion of the rudder 12, but it will be appreciated that other locations could be provided to vary the action of the section 16. Variation in this action could also be afforded by varying the The, vane structure 20 also hull of the boat 72 beneath the propeller 74'thereof. It-

will, be seen that the rudder section 70 defines a suitable air foil or hydrodynamic foil tapering and converging rearwardly from the relatively wide front portion 68, and having a generally torpedo-like cross sectional outline as also understood by those skilled in the art. The rudder section 70 is bifurcated from the rear-edge 76 thereof to define a coplanar slot 78 extending vertically therethrough and receiving a single piece rudder section 80 pivotally connected to the rudder section 70 by a pivot pin 82 corrmponding to the pivot pin 18 in the first embodiment of the invention.

A vane structure 84 is formed at the bottom of the rudder section 80 in integral relationship therewith, preferably so as to, be disposed in parallel abutting engagement with the bottom edge 86 of the rudder section 70 and in parallel alignment with the slip stream from the propeller 74 in the uppermost position of the section 80 shown in solid line in FIGURES 5 through 8.

In order to limit the pivotal movement of the section 80 around the pivot point 82, slot and pin means similar to those of the first embodiment are utilized including of the pivotally mounted section be relatively less than,

a pin 88 extending through the rudder section 70 in preferably horizontal alignment with the pin 82, and received in an arcuate slot 0 in the plate formed about a radius defined by the spacing of the pin 88 from the pin 82. Thus, the lower end of the slot 90 may serve as a stop defining the uppermost position of the plate 80 and the upper end of the slot 90 may act as a limit or stop to deline the lowermost position of the plate 80. As seenin FIGURE 6, this lowermost position may be inclined slightly less than ninety degrees from the uppermost position of the plate 80.

Since the vane 84 is formed integrally on the bottom edge of the plate 80, it afiords a continuous surface, as contrasted with the split surface afforded by the sections 36 and 38 of the vane 20 of FIGURES 1 through 4. Consequently, the vane 84 may have a somewhat smaller total width than the vane 20, and is otherwise similarly dimensioned and configured in relation to the weightof the plate 80 to provide a desired lifting action which varies automatically with the speed of the vessel to pivot the section 80 into registered alignment within thebifurcated section 70 at cruising speeds or relatively high speeds of the boat 72.

Although the pivotal sections 16 and 80 are shown as having a dimensional outline substantially corresponding to that of the rudder sections 12 and 70 to which they are pivotally secured, it will be understood that variations in this particular construction will be afforded within the scope of the invention. Thus, for example, particular conditions may require that the projected area or greater than, that of the rudder to which they are secured. Again, multiple pivoting action may be afforded by the provision of secondary sections (not shown) pivotally secured to pivotally mounted sections such as the sections 16 and 80. Also, the respective sections may be slidably mounted for relative movement by means of vanes positioned on the lower sections.

There has thus been providedpan expandable rudder of exceptionally simple construction whose area is variable directly proportionally to the speed of the vessel to which the rudder is secured, and in accordance with the nature of the medium through which the vessel moves, the

weight or other biasing factor inherent in the pivotally mounted section of the rudder, and the construction of the vane acting as an elevator for the said pivotally mounted section. The vane acts to reduce cavitation effects, and because no manual or other such adjustment is required, the device has extremely long wear characteristics, and is also entirely safe and reliable; It therefore has application in a wide variety of situations, and in fact, may be advantageously used in any craft or device which is steerable in a fluid medium.

Although I have herein set forth and described my invention with respect to certain specific principles and details thereof, it will be understood by those skilled inthe art that these may be varied without departing from the spirit and scope of the invention as set forth in the hereunto appended claims.

I claim as my invention:

41. A variable area rudder comprising a first rudder section, a second rudder section connected to the first rudder section for pivotal movement in variably lapping relationship with the first section about a horizontal axis and in a plane parallel to the first rudder section, steering means on the first rudder section for turning said rudder about a vertical axis and means responsive to fluid pressure on said second rudder section for varying its pivotal position relative to the first rudder section in accordance with the rate of movement of the rudder relative to an ambient fluid medium.

2. A variable area rudder comprising a first rudder section, a second rudder section connected to the first rudder section for pivotal movement in variably lapping relationship with said first rudder section and about a horizontal axis in a plane parallel to the first rudder section, Steering means on the first rudder section for turning said rudder about a vertical axis, and a vane on said second rudder section responsive to fluid pressure and configured and positioned to pivot said second rudder section relative to said first rudder section in accordance with the relative rate of movement of the rudder through a fluid medium and the resultant fluid pressure on said vane.

3. A variable area rudder comprising a first rudder section, a second rudder section pivoted to said first rudder section in variably lapping relationship and for movement in a plane parallel to said first rudder section, said second rudder section being configured and dimensioned to provide a control area for the variable area rudder substantially corresponding to that of the first rudder section in an uppermost position of the second rudder section and movable to a lowermost position wherein the control area of the variable area rudder is increased by a predetermined ratio for control of a craft or other object at low speeds, and vane means on said second rudder section responsive to fluid pressure for raising and lowering said second section between said upper most and lowermost positions in accordance with the rate of movement of the rudder through a fluid medium and the resultant fluid pressure on said vane means.

4. A variable area rudder comprising a bifurcated first rudder section, a second rudder section pivoted on said first rudder section in variably lapping relationship for movement in said first rudder section in a plane parallel to said first rudder section and configured and dimensioned to provide a control area for the rudder substantially corresponding to that of the first rudder section in an uppermost position of the second rudder section and movable to a lowermost position wherein the control area of the rudder is increased by a predetermined ratio for control of a craft or other object at low speeds, and vane means on said second rudder section responsive to fluid pressure for raising and lowering said second section between said uppermost and lowermost positions in accordance with the rate of movement of the rudder through a fluid medium.

5. A variable area rudder comprising a first rudder section, a second rudder section pivotally connected to said first rudder section in variably lapping relationship for movement in a plane parallel thereto, said second rudder section including a pair of plates connected in spaced parallel relation such as to receive said first rudder section in proximate relation therebetween and dimensioned to afford substantially the same control area as the first rudder section in an uppermost position thereof, and a combined control area with said first rudder section increased by a predetermined ratio in a lowermost position of said second rudder section, and vane means responsive to fluid pressure thereagainst and fixedly secured on said second rudder section for moving said second rudder section between said uppermost position and said lowermost position in accordance with the relative rate of movement of the rudder through a fluid medium and the resultant fluid pressure on said vane means.

6. In a variable area rudder, a pair of rudder sections connected for variably lapping pivotal movement in parallel planes, at vane on one of said sections responsive to fluid pressure and providing pivotal movement of said one section relative to the other of said sections in accordance with the relative rate of movement of the rudder through a fluid medium and the resultant fiuid pressure on said vane, an upwardly arcuate slot on the other of said sections and a pin on said of one sections received in said slot and guiding the movement ot' said one section between an uppermost position and a lowermost position relative to said other section and maintaining the sections in said lapping relationship.

7. In combination with a boat, a variable area rudder including a first rudder section, means connected to said first rudder section and said boat for turning the first rudder section about an axis to steer the boat, a second rudder section connected to the first rudder section in variably lapping relationship for pivotal movement about an axis substantially perpendicular to the first-named axis and in a plane parallel to said first rudder section, and a vane on said second rudder section responsive to fluid pressure and configured and dimensioned to rotate said second rudder section relative to said first rudder section in accordance with the rate of the boat through the fluid medium and the resultant fluid pressure against said vane.

8. A variable area rudder comprising a first rudder section, a second rudder section mounted for variably lapping coplanar movement relative to said first rudder section and vane means on said second rudder section responsive to fluid pressure and eflfective to afford said relative movement of said second rudder section relative to said first rudder section in response to said fluid pressure.

9. A variable area rudder for steering a vessel or other device with a control surface proportionate to the speed of the vessel comprising, an upper rudder section, steering means connected to the upper rudder section in supportiong relationship thereto, a lower rudder section, means pivotally connecting said lower rudder section to said upper rudder section for movement of said lower rudder section in coplanar, variably lapped relationship to said upper rudder section, and means on said lower rudder section responsive to fluid pressure from an ambient fluid medium to raise the lower rudder section relative to the upper rudder section and to reduce the effective steering area of the said variable area rudder proportionately to the speed thereof relative to the ambient fluid medium.

10. A variable area rudder comprising an upper rudder section, a lower rudder section, means connecting said lower rudder section to said upper rudder section in variably lapping, relatively movable and coplanar relationship therewith and means on one of said rudder sections responsive to fluid force for varying the lapping relationship of the lower rudder section to the upper rudder section proportionately to the said fluid force.

, 11. Ina variable area rudder, a pair of rudder sections, means retaining said rudder sections in variably lapping relationship for movement in parallel planes and a vane on One of said sections responsive to fluid pressure and providing movement of said one of said sections relative to the other of said sections upon variation of fluid pressure thereagainst to vary the overlap between said sections in accordance with the relative rate of movement References Cited in the file of this patent UNITED STATES PATENTS Wees et a1 Oct. 15-, 1901 Post July 3, 1928 Northrop July 10, 195-1

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