US 3643599 A
Retractable stabilizing fins and drag brake apparatus having coactive connection between the stabilizing fins and drag brakes. The stabilizing fins when deployed to a position perpendicular to the missile axis present an edge to air stream. The drag brakes when deployed to a position perpendicular to the missile axis produce aerodynamic drag as well as rotate the stabilizing fins to a position to produce aerodynamic drag.
Description (OCR text may contain errors)
United States Patent Hubich [4 1 Feb. 22, 1972  RETRACTABLE STABILIZER FlNS AND DRAG BRAKES FOR MISSILES  Inventor: Henry 0. iiubich, Upperco, Md.
 Assignee: The United States of America as represented bytheSeeretary of the Navy 221 Filed: July 22,1968
2n Appl.No.: 746,583
 U.S.Cl. ..l02/4, l02/34.l,244/3.27, 244/138 A [5 l] Int. Cl ..F42b 25/02 ISRI Field oISearch ..'....244/3.27, 3.28, l7.l3, 17.17, 244/138, 138.]; l02/4, 34.l
 References Cited UNITED STATES PATENTS 2,044,819 6/1936 Taylor 102/4 2,918,235 l2/l959 Aberg et al. ..244/l38 3,057,589 10/1962 Nutkins et al... 3,l8l,816 5/1965 Pfleiderer ..244/l7.l7
Primary ExaminerSamuel W. Engle Attorney-4.. A. Miller, Q. E. Hodges, A. Sopp and D. Mc- Giehan  ABSTRACT Retractable stabilizing fins and drag brake apparatus having coaetive connection between the stabilizing fins and drag brakes. The stabilizing fins when deployed to a position perpendicular to the missile axis present an edge to air stream. The drag brakes when deployed to a position perpendicular to the missile axis produce aerodynamic drag as well as rotate the stabilizing fins to a position to produce aerodynamic drag.
5 Claims, 4 Drawing Figures PAIENIEDF EB 2 2 I972 INVENTOR HENRY 0. HUB/CH ORNEY RETRACTABLE STABILIZER FINS AND DRAG BRAKES FOR MISSILES The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION The present invention relates to apparatus providing flight stabilization of missiles in both a fin-stabilized and drag brake mode at different times during the flight. Improved flight trajectory and subsequent low obliquity and low velocity at impact are obtained. The novel retractable and deployable flight stabilization system may be used on any type missile of either the self-propelled rocket type or the non-self-propelled projectile and bomb type and for any suitable use such as air to surface or surface to surface.
The function of fins for flight stabilization and drag braking individually on missiles is well known in the prior art; however, it has been found desirable to provide both functions for the same missile and by the use of the same fins. The present invention overcomes the disadvantages of the individual systems by combining the functions of fin stabilization and drag braking in one simple fin system mounted on the tail section of a missile.
SUMMARY The purpose of the instant invention is to provide control for a missile by means of one set of fins for accomplishing both fin stabilization during flight, and later aerodynamic drag braking prior to impact. By fin stabilization is meant the effect of reducing pitch and yaw of a missile by providing three or more fins having major surfaces parallel to the direction of flight. By aerodynamic drag braking is meant the effect of decelerating a missile by providing a fin having its major surfaces perpendicular to the direction of flight.
Optimum results are obtained when flight stabilization is provided throughout the major portion of the trajectory and drag braking occurs just prior to impact. This invention provides such separate and sequential functions using the same set of retractable and deployable fins. According to the invention, stabilizing fins are coactively connected to overlie the drag brakes in the launch configuration. The stabilizing fins, when rotated into the air stream, present their major dimension parallel to the direction of flight. The drag brakes, when rotated into the airstream, present their major dimension perpendicular to the airstream. Because of the coactive connection, between each stabilizing fin and a drag brake, rotation of the drag brake automatically causes 90 rotation of the stabilizing fin to produce aerodynamic drag in addition to that produced by the drag brakes.
Accordingly it is the principal object of this invention to provide a missile with both fin stabilization and drag braking in time sequence.
Another object is to provide a missile with fin stabilizers and drag brakes coactively connected to utilize both the fin stabilizers and drag brakes for aerodynamic drag.
Other objects and features of the invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a missile showing the stabilizer fins overlying the drag brakes and retracted for launching.
FIG. 2 is an end view from the missile tail showing the stabilizer fins deployed into the airstream.
FIG. 3 is a perspective view of a missile showing the drag brakes and stabilizer fins deployed to produce aerodynamic drag.
FIG. 4 is a detail cross-sectional view showing the release catches and springs for deployment of the drag brakes and stabilizer fins.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1, 2,3, and 4 wherein like reference numerals designate corresponding parts throughout the several views, there is shown a missile I0, such as a rocket. The missile I0 is configured to have a tail section I2 of reduced diameter, a cone shaped nose I4, and a propellant nozzle 16.
Four substantially similar stabilizer fins and drag brake assemblies located at cardinal points are attached to the missile tail section 12 and extend forward to lie flat and parallel to the body of the missile 10 as shown in FIG. 1, and in a deployed position shown in FIGS. 2 and 3.
In view of the similarity of design and operation of all of the fin assemblies, one assembly need be described in detail in the specification. Each assembly as shown in FIG. I comprises an inner drag brake 20 having a flat surface lying adjacent the missile body. In the position shown, the drag brake 20 extends toward the missile nose l2, and is releasably secured flush to the body by means of catch 28 or the like. Catch 28 is releasa ble in any suitable conventional manner such as by an explosive squib (not shown) activated by a timing device (not shown). The rear of drag brake 20 is hingedly attached to the missile 10 by a hinge joint 18 the axis of which is parallel to a major surface of drag brake 20 and parallel to a tangent of the missile body. Deployment is accomplished by a compression spring 32 positioned between the missile body 10 and the underside of drag brake 20.
Stabilizer fin 22 is shown in FIG. I as overlying the drag brake 20 and is coactively connected thereto by pivot 24. The axis of pivot 24 is perpendicular to the major surface of both drag brake 20 and stabilizer fin 22, and thus perpendicular to the axis of hinge joint 18. Thus the stabilizer fin 22 and drag brake 20 are in parallel planes and coactively connected.
Stabilizer fin 22 is releasably secured to the drag brake 20 in the overlying position shown in FIG. I by means of a catch 30 or the like. Catch 30 is releasable in any suitable conventional manner such as by an explosive squib (not shown) activated by a mechanical timing device (not shown). Deployment to a position as shown in FIG. 2 is accomplished by a torsion spring 34 providing torque about pivot 24. The spring 34 may be attached at the pivot 24 and biased to urge the stabilizing fin into the FIG. 2 position upon release of the catch 30.
The positive catch 30 is particularly advantageous when the missile is to be launched from a nonconfining launcher such as launching rails. Alternatively, if desired, catch 30 may be omitted when the missile is to be fired from a launching tube, in which instance the launch tube may serve to temporarily hold the stabilizing fins along or adjacent to the body of the missile. The fins are automatically deployed by springs 34 upon ejection of the missile from the tube and freeing of the fins from their restriction by the annular tube wall.
A stop 26 protruding from the drag brake 20 is provided to limit the rotation of stabilizer fin 22 about pivot 24 to the deployed position shown in FIG. 2.
Hinge joint I8 for the drag brake may be configured in any suitable, well known manner to suitably limit rotation of the drag brake 20 to a deployed position shown in FIG. 3.
DESCRIPTION OF THE OPERATION As shown in FIG. I, missile I0 is in a storage and launching configuration with both stabilizer fin 22 and drag brake 20 lying flat along tail section 12 and with their longitudinal axes parallel to the axis of the projectile. After launching missile 10 from its launching tube, stabilizer fin 22 is deployed by spring 34 after actuation of any conventional release mechanism such as catch 30 releasable by an explosive squib and mechanical timing device. Stabilizer fin 22, upon deployment, rotates by torque spring 34 outwardly from the body of missile about pivot 24 through an arc B," the plane of which is parallel to the flat surfaces of both the stabilizer fin 22 and the drag brake 20. In the deployed position the stabilizer fin 22 imparts yaw and pitch stability to the missile 10 to produce a more certain flight path. A suitable stop 26 mounted on the drag brake 20, limits the arc of rotation to approximately 90 as shown in FIG. 2.
As the missile nears a designated target another release mechanism such as a timing device and explosive squib, release catch 28 to deploy the drag brake 20 which by compression spring 32 is forced away from missile body to rotate about the hinge joint 18. When deployed through arc A" in FIG. 3) and stopped by appropriate stops which may, for example, be integral with the hinge joint 18, at a position shown in FIG. 3, the drag brake present its flat surface to the airstream. Furthermore, because stabilizer fin 22 is coactively connected to drag brake 20 by pivot 24 and already deployed, it is carried by rotation of the drag brake to a position shown in H0. 3 thus presenting its major surface to the airstream in addition to that of the drag brake. Thus when flight stabilization is no longer required and maximum drag is desirable, both drag brake 20 and stabilizer fin 22 act in each fin assembly in unison to produce aerodynamic drag reducing the velocity of the missile just before impact.
It is to be understood that the invention is not limited to the exact details of construction shown and described, for obvious modifications will occur to persons skilled in the art.
What is claimed is:
l. Stabilizing and drag apparatus for a missile comprising:
a plurality of drag brakes, each drag brake being pivotally mounted on the tail section of the missile for rotation from a first position to a second position about an axis perpendicular to the missile axis and approximately tangent to the surface thereof;
each of sad drag brakes having a first position essentially alongside a longitudinal surface portion of the missile;
a second position essentially radially outward from the tail section of the missile for producing aerodynamic drag; and
a stabilizer fin pivotally mounted on each drag brake for rotation about an axis perpendicular to the axis of rotation of said drag brake.
2. The apparatus of claim I further comprising:
drag brake release means for releasably securing said drag brakes in said first position alongside the longitudinal axis of the missile.
3. The apparatus of claim 2 further comprising stabilizer fin release means for releasably securing said stabilizer fins along and overlying said drag brakes.
4. The apparatus of claim 3 further comprising a spring biasing said drag fins outwardly from the body of said missile when in the first position.
5. The apparatus of claim 4 further comprising a spring attached between said stabilizer fin and drag brake biasing said stabilizer fin into a position perpendicular to the missile body.