US3407774A - Steering device for boats - Google Patents

Description

Oct. 29, 1968 A. J. BURKE STEERING DEVICE FOR BOATS 5 Sheets-Sheet 1 Original Filed Jan. 5, 1966 INVENTOR ARTHUR .z BURKE M70-4RM 7AM W5 ATT/RNEYS Oct. 29, 1968 A. J. BURKE STEERING DEVICE FOR BOATS sheets-Sheet 2 Original Filed Jan. 5, 1966 ATT RNEYS ct. 29, 1968 A J, BURKE STEERING DEVICE FOR BOATS 3 Sheets-Sheet 5 Original Filed Jan. 5, 1966 Pn/0T Axis oF RUDDER se INYENTOR ARTHUR BUR/(E BY Mm, M

' d AgoRNEYs United States Patent O 3,407,774 STEERING DEVICE EUR EGATS Arthur I. Burke, 28 Andrews Ave., (iakland, NJ. 074136 Continuation of application Ser. No. 518,929, dan. 5, 1966. This application Aug. 22, 1967, Ser. No.

6 Claims. (Cl. 1114-163) ABSTRACT GTF THE DSCLGSURE Related application This application is a continuation of my co-pending application Ser. No. 518,929, filed Ian. 5, 1966, now abandoned, for Steering Device `for Boats.

This invention relates to steering devices for waterborne vehicles and is particularly concerned with a novel marine steering device for improving the maneuverability of single-screw, fast-planing boats when backing down.

Fast-planing, single-screw boats of the type which this invention is especially concerned with, have a minimum of parts protruding downwardly from the hull bottom to minimize resistance and thus provide for a high forward speed with an inexpensive drive. These downwardly protrading parts usually are limited to a small keel, the propeller and shaft assembly, a shaft support strut, and the rudder. When moving forwardly in boats of this type, the propeller pushes the water past the rudder to thereby make the rudder effective for maneuvering the boat. In reverse, however, there is only a very small vertical surface against which the propeller wash is directed with the result that the maneuverability of the boat is degraded.

Typically, the stern of a fast-planing, single screw boat tends to go to port when equipped with a righthand screw. This occurs even with the slightest reverse motion of the boat and is the result of a swirling mass of water which is driven forwardly against the bottom of the hull by the propeller. The water in this mass, when looking forwardly, moves counterclockwise around the propeller shaft and exerts a force on the hull and the propeller shaft support strut to push the stern to port. This mass of water also exerts a force on the hull bottom to slow reverse motion of the boat since it opposes the suction force of the propeller.

Prior to this invention, some proposals have been made for improving the maneuverability of a boat when backing down, but none are satisfactory for fast planing boats of the type described above since they all have additional control surfaces protruding from the bottom of the hull which are of such size and which are in such locations as to objectionably impede the boats forward speed. Some of these prior devices involve unbalanced rudder surfaces which are retractable to an inoperative position within the boat when moving in a forward direction. This, however, requires a specially constructed hull and expensive apparatus for retracting the rudders. The retractable rudder arrangement thus is entirely unsuitable and impractical for use in the standard inboard runabouts, utilities, sport fishermen, sedans, and cruisers in the cousumer market.

In overcoming the foregoing problems, the major object of this invention is to provide for a novel steering device for improving the maneuverability of a boat without objectionably impeding its forward speed capabilities.

A more specific object of this invention isvto provide a single-screw boat with a novel sternway rudder steering device which is located just forwardly of a conventional rudder and screw and above the propeller shaft and which has a control surface in the wash of the propeller when backing down.

By confining the sternway rudder device of this invention to the region above the propeller shaft, negligible turbulence, if any, is produced in the stream of water leading to the propeller when the boat is moving in a forward direction. As a result, the forward speed of the boat is not diminished. When backing down, the rudder device of this invention and the conventional rudder, which is aft of the propeller, are operatively connected so that their movement is correlated and unitary.

Still another object of this invention is to provide a novel sternway marine steering device which is simple in construction, inexpensive to manufacture and install, and requires little or no maintenance.

A further object of this invention is to provide a novel sternway steering device which is in a protected location vertically above the propeller shaft and below the boat hull where it does not constitute an objectionable obstruction to streamline flow of water around the hull.

Another object of this invention is to provide a novel sternway steering device which is easily added as an accessory to the steering system of a boat without interfering with the basic stability of the system.

Further objects of this invention will appear as the description proceeds in connection with the annexed claims and appended drawings wherein:

FIGURE 1 is a side elevation of a boat incorporating the sternway steering device of this invention and illustrating the hull to be broken away to show interior details;

FIGURE 2 is a section taken substantially along lines 2-2 of FIGURE 1 and illustrating the motion transmitting linkage operatively connecting the main rudder to the sternway rudder of this invention;

FIGURE 3 is a fragmentary section in elevation illustrating a modified embodiment of this invention;

FIGURE 4 is a fragmentary elevation illustrating another embodiment of this invention;

FIGURE 5 is a fragmentary elevation illustrating still another embodiment of this invention;

FIGURE 6 is a section taken substantially along lines 6 6 of FIGURE 5 and showing the sternway rudder device of this invention positioned for sternway Steerage to starboard; and

FIGURE 7 is a partially schematic view looking from starboard toward port for comparing the differences in steering control achieved by the rudder in FIGURE 5 and the rudder in FIGURE l.

Referring now to the drawings, and more particularly to FIGURE l, the reference numeral lil generally designates a power driven, single-screw boat having a conventional, fast planing hull l2 which may be formed with a keel i4 of minimum depth. Boat 10 may be of any inboard type such as, for example, a runabout, a utility vessel, a sport fisherman, a sedan, or a cruiser and is shown to have Ia suitable engine 16 mounted in hull 12.

With continuing reference to FIGURE 1, engine 16 is operatively connected through a conventional transmission gear box 17 to a propeller shaft 18 which extends rearwardly through the bottom of hull 12. The portion of shaft 18 projecting from the bottom .of hull 12 is shown to be inclined downwardly at an acute angle with respect to the horizontal and is spaced below the bottom of hull 12 at the stern of the vessel. Gear box 17 may be of any main steering rudder 26 is mounted on a vertical rudder- A post 28 which extends through hull l2 and which is rotatably supported about an axis intersecting or passing closely adjacent to the rotational axis of shaft 18. Rudder 26 is disposed adjacent to and rearwardly of propeller so that its steering control surfaces are located directly in the propeller wash when gear box i7 is shifted to its forward drive. Any suitable means such as a wheel 3d is operatively connected to rudderpost 28 as by a motion transmitting cable 32 to swing rudder 26 about the axis of rudderpost 28 for steering the boat in a known manner.

The boat construction thus far described is conventional and is known to provide for high forward speeds owing to the conguration of hull l2 and the minimum number and size of parts projecting downwardly from the bottom of the hull l2. In this embodiment only rudder 26, shaft 13, strut Ztl, and keel ld provide the major surfaces on which the water acts to resist the driven `motion of the boat. It will be appreciated that hull l2 may also be formed without a keel.

This type 4of boat typically is difficult to maneuver when backing down since there is a minimum of vertical surface against which the propeller wash can be directed. Without the incorporation of this invention, the stern of such boats tend to go to port when equipped with a right-hand propeller. This is the result, as previously 2 mentioned, of a mass of water swirling around shaft i8 partially in the same direction of propeller rotation and moving forwardly against the bottom of hull l2 in the region of shaft 18. The rotation of this mass of water swirling in a counterclockwise direction and acting on hull i2 and struct Ztl tends to push the stern of the boat to port.

In accordance with this invention, a sternway steering control device is provided to overcome these problems of maneuverability when backing down and is shown in FIGURE 1 to comprise a fiat-sided sternway rudder 36 which is mounted on the lower end of a vertical rudderpost 3S. Rudderpost 38 preferably is parallel with rudderpost 2S and is shown to extend through hull l2 along an axis substantially intersecting the axis of shaft i8 forwardly of strut 2i). A bearing and seal collar 39 bolted to hull 12 rotatably mounts rudderpost 38. The axes of rudderposts 28 and 3S and shaft 18 preferably are contained in a common vertical plane and are located substantially midway between opposite sides of hull l2.

As shown, rudder is formed with fiat, parallel, oppositely facing steering control surfaces and is located completely above shaft l?) in the space delimited by strut 20, the bottom of hull l2, and shaft iii. Thus located, it is clear that -rudder 36 is directly in the wash of propeller 24 when reversed to cause sternway movement. ireferably rudder 33 is of the partially balanced type having steering control surfaces fore and aft of the rudderpost axis.

The upper end of Arudderpost 33 extending above collar 39 is connected to rudderpost 2S by a suitable motion transmitting linkage il which, as shown in FIGURE 2, may comprise a pair of arms 42 and 4d and a rigid link 46. Arms 42 and 44 `are respectively iixed to rudderposts 28 and 38 and pivotally connected by pins 47 to opposite ends of link 46. With this construction, it is apparent that the movement of rudders 2r? and 36 are correlated and unitary.

Rudders 26 and 36 are so connected by assembly dit that they are rotated in the same direction about the axes of their respective rudderposts and are essentially both centered in a given position of wheel 36. Although rudders 26 and 36 may be connected to move in substantially parallel planes, it is preferable that rudder 36 slightly oversteers rudder 26 to improve the maneuverability of the boat when backing down.

Advantageously, one of the pins 47 is removable to disconnect rudder 36 from rudder 26. Suitable uushown means may be employed to lock rudder 36 in its centered position when disconnected from rudder 26.

During sternway movement, the increased vertical steering control surface provided by rudder 36 directly in the propeller wash counteracts the tendency of the stern of the boat to go to port since the force of the forwardly moving mass of water swirling around shaft 18 acts on rudder 36 to move the boat in a starboard direction. In effect, rudder 36 atords the same stability in steering during sternway movement as does rudder 26 for forward movement. When backing down and before sternway movement takes place, it has been found that rudder 36 provides for maximum effectiveness when turned to one extreme position or the other. This apparently is due to the fact that the flow lines in the forwardly moving mass of water swirling around shaft 18 become less axial as sternway movement is decreased. Thus, by turning rudder 36 to either of its extreme port or starboard positions, a maximum projected rudder control surface arca is presented to the axial component of the propeller wash to thereby obtain the maximum control action offered by rudder 36 before sternway movement begins.

Ey locating rudder 36 in a region of turbulent iiow around hull l2, the resistance oifered by rudder 36 to high forward speeds is insignificant. Furthermore, confinement of rudder 36 to a position vertically above shaft 18 as shown in FIGURE l adds little, if any, turbulence to the stream of water leading to propeller 24 when the boat is moving in a forward direction. Accordingly, it is evident that the sternway rudder control device of this invention does not compromise the forward speed capabilities of the boat and is located in such a position as to provide for maximum control with a minimum of rudder surface area. Since rudder 36 is of a partially balanced construction, it does not materially alter the basic stability of the steering system in either forward or sternway travel. To further increase the maneuverability of the boat when backing down, a rudder extension (FIG- URE 4) may be secured to rudder 36 by a suitable bracket assembly 56 to extend below propeller shaft 18. This rudder extension, however, increases the resistance to forward movement.

Compared with the vulnerable location of [rudder 26, rudder 36, being confined in the space delimited by shaft 18, strut 26, and hull l2, is protected against damage. Should rudder 26 become damaged, it may be disconnected from rudder 36 which then may be used to provide some control for forward steering in an emergency.

FIGURE 3 illustrates a modified embodiment of this invention wherein a sternway rudder 60 is incorporated as part of a propeller shaft support strut assembly 62. Assembly 62 is shown to comprise a cylindrical post 64 which is fixed to and extends downwardly from the bottom of hull i2 along an axis intersecting the rotational axis of shaft 1S. The lower end of post 64 is rigidly fixed to a sleeve 66. Shaft 18 coaxially extends through sleeve 66 and is journalled therein by a suitable bushing 68.

Still referring to FIGURE 3, post 64 coaxially extends through a rudder mounting sleeve 70 and terminates at its upper end in an enlarged head which is seated on the upper end of sleeve 7 ti within hull 12. The upper portion of sleeve '70 is journalled in a bearing and seal collar 72 by a suitable sleeve bushing 74. Collar 72 is bolted in place within hull 12. A key 76 or other suitable means carried by sleeve 70 is disposed axially between collar 72 and arm d4 to axially retain sleeve 70 and post 64 in place. Rudder 66 is fixed to sleeve 70 which is rotatable about the axis of post 64. The lower end of sleeve 70 is seated on a boss portion formed integral with sleeve 66.

As shown, rudder 60 is disposed just forwardly of propeller 24 so that it is very close to and directly in the propeller wash when gear box 17 is shifted to its reverse position for sternway movement. Thus located, rudder 60 provides for exceptional steering control when backing down. Rudder 60 preferably is partially balanced as shown. Operation of rudder 60 for controlling sternway movement is the same as that explained for rudder 36.

FIGURES 5 and 6 illustrate a modified sternway rudder assembly having a rudder 100 mounted on a rudder post 102. Post 102 extends through the hull of boat 10 and is adapted to be connected by linkage 40 to rudder 26 in the manner described in the previous embodiments. Rudder 100 is disposed in the space vertically above shaft 18 and forwardly of strut 20 similar to the embodiment illustrated in FIGURE l. The axis of post 102 intersects or is closely adjacent to the axis of shaft 18.

In the embodiment of FIGURES 5 and 6, the post 102 and rudder 100 are inclined rearwardly such that the axis of post 102 is at an acute angle with a vertical plane and more normal with respect to the downwardly inclined axis of shaft 18 as compared with the sternway rudder of FIG- URE 1. The rearward edge of rudder 100 is thus tilted downwardly.

The portion of rudder 100 that is to the stern of the axis of post 102 is provided with larger steering control surface areas than that which is disposed forwardly of the rudder post axis. As a result, the rearward portion of rudder 100 has a correspondingly greater effect on steering than the forward portion thereof. The forward portion of rudder 100 provides a partially balanced condition when the rudder is turned in either direction from its cen tered position to improve the stability in steerage and to thus prevent the triggering of sudden movements of the boat when backing down.

Propeller 24, as previously described, is a right-hand screw which produces a forwardly moving, swirling mass of water. The part of this mass of water which influences rudder 100 directly is shown to be in cylindrical form and is indicated at 104. By inclining rudder 100 in the manner illustrated in FIGURE 5, the rudder control surface disposed rearwardly of the rudder axis is impinged by the largest amount of mass 104 possible for the limited height between shaft 18 and the boat hull. As shown, the Ipivot axis of rudder 100 is tilted in a direction that at least approaches perpendicularity with the mean or average direction of flow in mass 104.

The effective height of the control surface of rudder 100 which is disposed rearwardly of the rudder axis and which is closely at right angles to the average or mean direction of flow in mass 104 is indicated by dimension a in FIGURE 7. Dimension b indicates the corresponding effective height of rudder 36 which is normal to the average direction of flow in mass 104. It will be observed that the direction of flow throughout mass 104 is not exactly uniform. Direction of flow immediately adjacent to shaft 18, for example, is more axial than the direction of flow at a radius equal to that of propeller 24. Also, the flow components in elevation and in a vertical plane containing the axis of shaft 18 are essentially parallel to shaft 18, whereas elevational flow components contained in parallel vertical planes spaced laterally to the starboard side of shaft 18 are upwardly inclined relative to shaft 18. Accordingly, the average or mean direction of these flow lines impinging against rudder 100 is herein considered in explanation of the significant improvement in steerage control achieved by using `an inclined sternway rudder.

Since dimension ais appreciably greater than dimension b, as shown in FIGURE 7, a more effective sternway control to starboard is obtained with rudder 100 as compa-red with a rudder that is not inclined.

While improving sternway Steerage to starboard, the

tilting of rudder renders sternway Steerage to port less effective as compared with the control obtained by employing rudder 36. When using rudder 100, however, the overall control to port is effectively balanced with the control to starboard as la result of the influence of the propeller wash on the boat hull when propeller 24 is reversed to `back down. By inclining rudder 100, therefore, effective use is `made of the natural tendency of the boat to go to port to provide a balanced sternway control action in port and starboard directions. Similar to the embodiment of FIGURE 4, rudder 100 also may be provided with an extension disposed below shaft 18.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be lconsidered in all respects as illustrative `and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the `meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. In combination with a single screw, power driven boat having a hull, a propeller shaft protruding from the bottom of said hull, means supporting said shaft from said hull for rotation about an axis extending longitudinally of said hull, a propeller mounted on said shaft at the stern of said hull, and a steering rudder disposed rearwardly of said propeller, 'the improvement of a sternway steering control device comprising a. rudder member disposed forwardly of said propeller and in the propeller lwash when said propeller is rotated in a direction to back down, said rudder member being mounted for selective swinging movement about an axis that is tilted from a vertical plane in a direction at least approaching perpendicularity with the mean direction of rising flow lines in the propeller wash.

2. The combination dened in claim 1 wherein the rotational axis of said rudder, said rudder member, and said shaft are contained in a substantially common, vertical plane medially intersecting said hull.

3. The combination defined in claim 1 wherein in addition to said rudder member the parts projecting downwardly from said hull essentially consist of said shaft, said propeller, said rudder, a strut supporting said shaft and a relatively small keel disposed only forwardly of said rudder member, the combined area of the vertically oriented surfaces of said shaft, said propeller, said rudder, said strut, and said keel being sufficiently small that in absence of the Steerage control provided by said rudder member said -boat has a tendency to move either to port or starboard when the propeller rotation is reversed for imparting sternway movement to said boat, the operation of said rudder member being effective to compensate for said tendency.

4. The combination defined in claim 3 comprising means operatively connecting said rudder and said rudder member together for unitary movement, said rudder member being disposed completely above said shaft and in the space delimited by said hull, said shaft and said strut, with the rotational axis of said rudder member sub stantially intersecting the rotational axis of said shaft.

5. The combination defined in claim 3 wherein said shaft is tilted `downwardly from said hull at an acute angle with a horizontal plane and wherein the rearward edge of said rudder member is `also tilted downwardly, said rudder member having steering control surfaces disposed both rearwardly and forwardly of the rudder member rotational axis, the area of the rearwardly disposed surfaces being greater than the area of the forwardly disposed surfaces, the inclination of said rudder member be` ing effective to increase the height of its Steerage control surfaces which at least approach perpendicularity with the mean direction of rising ow lines in the wash produced by reversely rotating said propeller.

6. A sternway Steerage control device for a power 'driven boat having a p'ropeller rotatably supported from the stern of said hull, said sternway Steerage contr-ol device comprising a rudder member disposed just Vforwardly of said propeller and in the propeller wash when said propeller is reversely rotated for imparting sternway movement to `said boat, said rudder member being mounted for selective swinging movement about an axis that is tilted from a Vertical plane in a direction at least approaching References Cited UNITED STATES PATENTS 6/1929 Ward 114-163 9/1958 Scott 114-163 10 ANDREW H. FARRELL, Primary Examiner.

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