US1536317A - Steering mechanism - Google Patents

Description

May 5, 1925. 1,536,317

R. 1 1. UPsoN STEERING MECHANI SM Patented May 5, 1925.

UNITED STATES PATENT IOFFICE.

RALPH H. UPSON, 0F AKRON, OHIIO, ASSIGNOR TO THE GOODYEAR TIRE @a RUBBER COMPANY, OF AKRON, OHIO, A CORPORATION OF OHIO. i

STEERING MECHANISM.

Application filed May 1,

To all whom t may concern:

Be it known that I, RALPH H. UrsoN, a citizen of the United States, and resident of Akron, Ohio, have invented new and useful Improvements in Steering Mechanisms, of which the following is a specification.

The present invention relates to improvements in lighter-than-air craft and more particularly to those of the selfpropelled type and has for its principal object the provision of an automatic control for the steer-` ing and stabilizing thereof.

It is a recognized fact that a dirigible or airship in iiight is not inherently stable in a directional sense, that is, if the rudder were not used the ship would keep turning around indefinitely in one direction or the other due to the fact that the gas-bag itself is not in equilibrium while in motion, (unless it is going up or down sharply, or around in a curve). The (stationary) fins tend to make this natural turning circle a little larger in radius than it would otherwise be, but they are not nearly large enough to keep the shi headed straight. The fins are very ineliiclent in this respect, and the modern tendency in design is to use less and less of the immovable fin surfaces and to use more of the movable or steering surfaces instead. In this Way the control becomes more positive, the ship is less sluggish in its movements and the stabilizing apparat-us is reduced in weight and resistance.

In any of the above mentioned cases, however, attention to steering has to be continuous to get good results, since, if the ship is allowed to turn more than 2 or 3 degrees ott its course, it is liable to go 90 degrees or more before its turning movement can be stopped and it can be, brought back, resultingr in a serious change of course (or of gas pressure il the turningr be in a. vertical plane).

It is of greatest importance in the steering to be able tovdetect the slightest turning away from the course in order to correct it before it has gone too far. This can not usually be done by reference to the compass alone as this instrument is too sluggish to indicate very small movements. The best that can usually be done with the compass is to get the general average direction from it and then go by some object outside, as for 1919. Serial No. 294,071.

instance a star, cloud or some land mark on the horizon ahead, which can be kept in line with some cable or other visible mark on the balloon. Sometimes when the ship is nosing up, or in the absence of suitable marks ahead, it will be found better to turn around and watch the tail. Thus it will be seen that the greatest problem in steering an airship is not to turn it but tokeep it from turning.

It is with the above objections and disadvantages in mind that I propose to equip vthe steering rudder with an automatic dynamic neutralizing vane which will derive its powerfrom the various forces which are at once the cause and the eiect of the turning movement itself, namely, a displacin cross wind and the wind pressure against t e balloon on the outside of the flight path curve.

The many important objects and advantages of my invention will readily become apparent from a perusal of the drawlngs and specification and of the appended claims in which they are more particularly pointed out.

In these drawings, wherein there has been illustrated a preferred embodiment of the invention, and throughout the several views of which similar reference characters designate corresponding parts:

Figure lv is a perspective view showing the rudder system including the rudder neutralizer, all as applied to a dirigible;

Figure 2 is a plan view of the system;

Figure 3 is an elevation showing a modilied lform of the invention; and

Flgure 4 is a (perspective view showing the system applie to both the side and the bottom of the gas bag of a dirigible.

When a dirigible in flight turns, the relative wind always hits it on the outside of its flight path curve. This is magnified at the rear end by the fact that the tail swings around a longer radius arm against the air. This action of the air in hitting on the outside of the flight path curve is n'ot only an effect but is also usually a cause of the very turning movement itself, that is, if a sudden gust of wind hits the balloon on one side, it causes the nose of the balloon to turn away from that side. A turning movement when once started continues to accelerate up to a certain point and the balloon continues to travel around in short circles in the saine direction until something is done to prevent it from so doing. At present with the old system o f control, the pilot, of course, has to force the balloon into a straight course again with his manually operated controls. The adaption of my neutralizar vane to the rudder eliminates the necessity for this constant manual control, and also makes such control easier when it is necessary to use it. In the construction illustrated in the preferred embodiment of my invention (see particularly Figs. 1 and 2), the numeral 10 designates the gas ba-g or envelope proper, 11 a relatively stationary member hereinafter called a stabilizing fin and 12 a movable plane hereinafter designated as asteering rudder. In this instance the rudder 12 is designed in the shape of an L the trailing or rear portion 13, being the main steering surface, is made widestl while the leading or forwardly projecting portion 14 is made comparatively narrow. The rudder as a whole is hinged in any suitable manner to the rear end of the stabilizing fin 11 as at 15. The leading portion 14 carries, projecting forward therefrom, a pair of pivot members 1G, which provide a mounting for a differentially balanced (5in this instance) movable surface or plane, hereinafter called a neutralizing or control vane 17.

An operating arm 18, which is pivotally mounted between the outer end of the hinge 15 and the leading portion 14 of the rudder 12, has its ends connected through the medium of cords or cables 20 to a similar, though usually shorter, arm 19 secured to the inner pivot member of the neutralizing vane 17, to turn the vane. The arm 18 is ordinarily held essentially at right angles to the iin surface 11. In this way the vane 17 is constrained to assume a substantially fixed position (usually nearly parallel to the fin 11 depending upon the relative lengths of the arms 18 and 193 for each different position of the rudder 12.

As long as the ship tends to travel straight through the air the rudder and vane keep essentially in their neutral positions. When a gust of wind hits the ship a little to one side it tends to force the nose of the ship in the direction of the gust. This same gust, however, acts against the vane 17 which automatically turns the rudder 12 to such a position that it neutralizes the effect of the gust and holds the ship on a straight course. If the ship be assumed to have already been started on a curved path for some reason, .the action of the vane is still more marked, and by its effect on the rudder immediately tends to bring the ship to a straight course again. l

This is true because the swinging of the tail of the balloon against the gust increases the pressure of the cross wind on the vane 17 and causes the vane to respond to a greater degree than if acted on by the unassisted gust. This effects a much greater corrective action by the rudder than is developed by the pressure of the gust unassisted by the movement of the balloon.

If, for any reason, the tail of the balloon swings laterally from its direction of flight when there is no side wind blowing, this lateral movement of the tail develops a cross wind pressure on the vane 17 which turns the vane in a direction to stabilize the flight of the balloon.

It will therefore be understood that the term cro'ss wind refers to any lateral wind pressure on the control vane that may be developed by an actual ust blowing at an angle to the direction of ight of the balloon, or by a pressure that is developed by he lateral swinging of the tail of the baloon.

The arm 19 is so mounted as to permit of independent movement of the rudder and is designed to be manually controlled. To accomplish this, control wires 21 which are connected to the ends of the arm 18, are carried forward to the pilots car and secured to some appropriate adjustable controlling means, not illustrated. Used in this manner the action of the vane is similar to that of a Servo motor or rudder engine on a Steamship, since the wind force on the small vane surface furnishes the power which supplements the movements of the rudder under the manual control of thel pilot. There is this difference, however, from the action of an ordinary rudder engine; that the rudder engine controls the angle of the rudder whereas the neutralizing vane controls directly the turning radius of the ship in accordance with the lateral wind pressure. In the latter case the vane acts automatically to keeping the balloon ou the desired curved path in the same way as it ordinarily acts in keeping the balloon on a straight path.

In addition, the rudder 12 may be arranged to be manipulated in the usual mauner, and for the purpose of illustration I have shown in the drawings, particularly Figs. 3 and 4, control wires 22 connecting the rudder with control mechanism disposed in the pilots carbut not shown in the drawing.

In the modification illustrated in Fig. 3 a similarly shaped rudder 12 is used as before, but in this case'the partially balanced neutralizing vane 17 is done away with and in its lace a vane 24 is used. This vane 24 is hinged at one end to the end of the leading portion 14 of the rudder 12 as at 25 and carries a slide 26 at its free end having sliding engagement with a. rod orsimilar structure 27 which may be secured to the under side of the stationary fin 11. This permits the rudder proper to be manipulated bythe control cords 2 2 to swing the rudder on its response to the movement of the rudder since.

the slide 26 is free to move along the rod 27.

Thus it will be seen that any movement of the ship from the straight Hight path curve, caused either by the nunmal manipulation of' the rudder controls or by a sudden increase iii wind vpressure on either side of the envelope, will cause a corresponding air pressure on the outsidc of the neutralizing vane. As soon as the pilot releases the rudder controls 22, the dynamic action of the neutralizer will return the ship to a straight |course Without the necessity of the pilot having to reverse. the direction of the rudder to catch the ship before it has turned too far. The action is the same in the case of a sudden gust of wind striking thesl'iip when ruiming, causing the rudder to turn slightly inthe opposite direction which tends to keep the ship on a straight course.

In Figure 4 I have. shown, in addition to the stabilizing fin 11 and rudder 12, a stabilizing fin 11" vand elevating plane 12a connected to the vane 24, the elevator being operated by control wires 22a, the structure being analogous to that shown in the modification shownin Fig. 3. It will be understood that thel vane 24a in this modification has an effect similar to the vane 24 of the modification of Fig. 3.

. It will be observed that, in my device, the several vanes tend to aline themselves with the direction of travel, thus obviating the necessity for the use of springs, dash pot devices, and the like, for effcctingthe return of the varies to their respective normal positions after being displaced by lateral wind pressures. This novel characteristic of operation is obtained by employing what I shall term under-balanced surfaces to describe a surface or combination of coacting surfaces which inherently tend to aline themselves with the direction of travel in response to the head wind. In contradistinction with this, the term over-balanced surfaces may bc applied to surfaces or combinations of surfaces which, when moved out of alignment with the direction of travel or out of their normal positions in response to lateral positions.

In the employeinent of' under-balanced surfaces, the corrective tendency of the rudder system responds in proportionate degiec to the value of the lateral Wind pressure thus providing a system in Which the operation is such as to produce an `immediate response to displacing influences and to impose a corrective action that varies in accordance with such disturbances. The operation ofsucli a system may more properly be described as a system in which the rudder counteract influences which tend to disturb the direction of flight ofthe aircraft.

When over-balanced surfaces are employed, the response of the rudder system to disturbing lateral pressures is delayed until the influence becomes suciently great to overcome the action of the spring mechanisms which 4maintain the venes in a dead center or neutral position.. Such a rudder system gives a delayed but exaggerated corrective infiuence, whereas a rudder system constructed in accordance with the principles of my invention provides an immediate response and a degree of corrective influence that depends upon the intensity of the disturbing influence. In-the latter case complete automatic directional stabilization of the balloon is effected whereas in the former case the corrective influence must be supplemented by manual control;

It will be observed that, in my invention. anunder-balanced rudder system is provided by mounting the rudder vane and the control vane forward of their respective centers ofpressure. An additional advantage that obtains with such a structure is that, although the turning of the control 'vane around its pivotefiects the corrective movements of thc rudder vane, the control vane presents a positive incidence to the head Wind which operates through the/pivotal mountings of the control vane to returnthe rudder vane to its normal position. The pressure from the head Wind also tends to aline the control vane with the direction of flight and thereby acts through the cable connections of the system to return the rudder vane to its normal position. The degree of movement of the rudder vane in response to a given lateral` wind pressure may be controlled by proporticning the relative sizes of the acting surfaces, the spacing of the pivotal inountings and the relative lengths of the arms 18 and 19 to obtain more or less intensive corrective action.

In the foregoing description and drawings I have assumed for illustration certain relative positions, sizes, shapes, and angles for the respective surfaces. derstood, however, that individual designs of different airsliips may call for proportions, in the above respects, very different from those here shown. The ideal design I in eachv case is to produce a ship which re- L mains as nearly neutral as possible for different angles of yavv.

Itis to be understood also, that although I have illustrated and described my im- PI'OVed structure as applied to the steering 12" rudders of airships it may equally as Well be a plied to, heavier-than-air craft, captive alloons, boats, submarines and other fluid craft. It may also be applied to the elevating fins and stabilizers of such craft lao pai It is to be un- 1^ without departing from the spirit of my invention or the scope of the appended claims.

IVhat I claim is:

1. In a craft of the type described, a relatively fixed stabilizinor tin, a rudder swingingly secured to said iin, means for operating said rudder, a neutralizing vane swingingly secured to said rudder, an arm connected to said vanel,y and means for operating said arm to change the angle between said vane and said rudder.

2. In a craft of the type described a relatively fixed stabilizing fin, a rudder swingingly secured to said lin and having a rearwardl \Y extending portion and a forwardly extending portion, a neutralizing vane swingingly secured to the forward portion of said rudder, an arm pivotally mounted on said fin between said forward portion of said rudder and said lin, said arm being connected to said vane, and means for operating said arm to change the angle between said vane and said rudder.

3. In a craft of the type described, a relatively fixed stabilizing fin, a rudder swingingly secured to said fin and having a rearwardly extending portion and a forwardly extending portion, a neutralizing vane swingingly secured to said forwardly extending portion of said rudder, a control arm pivotally mounted between said fin and above said forwardly extending portion, a shorter arm secured transversely to said vane and connected to said control arm, and means for operating said control arm to change the angle between said vane and said rudder.

4. A rudder system for Huid-navigating craft comprising, a stabilizing fin, a rudder rane pivotally mounted on the fin, a control spar pivotally mounted on the fin and movable independently of said rudder vane, a control vane pivotally mounted in front of its center of pressure on the rudder vane, a second spar rigidly attached to the control rane, control lines extending between said spars, and means for manually changing the position of said. control spar.

5. A rudder system for fluid-navigating craft comprising, a relatively fixed iin, a rudder vane pivotcd to the n, a control vane pivotcd to the rudder vane, a spar rigidly secured to the control vane, a second spar pivotally mounted independent of the rudder vane, connecting means extending from the first spar to the second spar and means for manually controlling the rudder vane by changing the position of the second spar.

6. A rudder system for air craft comprising a rudder vane, a control vane carried by the rudder vane and free to turn under wind pressures, said control vane being so connected tosaid rudder vane as to move the rudder vane in response to a turning movement ofthe control vane to counteract the infiuence of lateral wind pressures on the air craft, said control vane in its turned position presenting an incidence to the head wind which tends to return the rudder vane to its normal position, the head wind also acting on the control vane to turn the same to its normal position.

7. A rudder system comprising a rudder vane, a control vane carried by the rudder vane and responsive to the head wind to maintain the rudder vane in a normal position, said system being responsive to lateral winds for moving the rudder vane out of its normal position and responsive to both the lateral wind and the head Wind for returning the rudder vane to its normal position.

8. A rudder system comprising a relatively large rudder vane, a smaller control vane differentially mounted intermediate its extremities and free to move under wind pressures, and means for operating the rudder vane from the control vane in such manner as to automatically control the position of the rudder vane in accordance with the wind pressures on the control vane, said vanes being so mounted as to severally tend to aline themselves with the direction of travel in response to the head wind.

In witness whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

RALPH II. UPSON.

IVitnesses:

L. M. HARTMAN, E. C. LEADENHAM.

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