ARROW FLUID-DYNAMICS

• US 3,751,037 A
• Filed: 11/04/1971
• Issued: 08/07/1973
• Est. Priority Date: 11/04/1971
• Status: Expired due to Term

• Current Assignee: Calice G. Courneya
• Original Assignee: Calice G. Courneya
• Inventors: Courneya, Calice G.
• Primary Examiner(s): Oechsle, Anton O.
• Assistant Examiner(s): Shapiro, Paul E.
• Application Number:
  US05/195,554
• Time in Patent Office: 642 Days
• Field of Search: 273/16.5C,16.5R 244/3.23
• US Class Current: 473/586
• CPC Class Codes: F42B 10/22 Projectiles of cannelured type
• CPC Class Codes: F42B 10/26 using spin F42B10/04, F42B10/12, F42B10/14, F42B10/24, F42B14/02 take precedence
• CPC Class Codes: F42B 6/06 Tail ends, e.g. nocks, fletching

Abstract

Disclosed is a new means to cause rotation of a missile as it moves through a fluid, which means maintains the missile in alignment with its direction of movement through the fluid. The means consists essentially of fluid-dynamically spaced elongated depressions in the gross outer surface of at least some portion of the trailing half of the mass of the body part of the missile. These depressions are aligned on the gross outer surface within an angle not greater than 30* from the axis of missile rotation. Each depression has a maximum width and maximum depth less than the length thereof, and also less than the radius of the circumference generated by rotation of the body portion of the missile at the location of the depression. Further, these depressions have a greatest depth portion radially-displaced with respect to a lesser depth portion and this greatest depth portion is forward of the longitudinal midpoint of the depression. The depressions are especially effective to guide the flight of missiles such as arrows, and can be used to replace the normal feathers or fins on standard archery arrows. Each special depression, during transit of the missile through a fluid, creates a resultant fluid-dynamic composite force vector which lies in a line not intersecting the longitudinal axis of rotation of the missile, but passing laterally to that axis. The composite force vector line of each depression passes that axis on the same lateral side, thereby effecting rotation of the missile.

Claims

1. A missile comprising (a) an elongated body portion fluiddynamically rotatable about a longitudinal axis thereof, the mass of said body portion being substantially fluid-dynamically symmetrical in radial planes perpendicular to said axis, and the gross outer surface of said body portion being fluid-dynamically substantially smooth, (b) a leader and trailer at opposite ends of said body portion, at least said leader being fluiddynamically pointed, (c) and means effective during transit of said missile through a fluid to cause rotation of said body portion about said axis and thereby maintain the missile in alignment with its direction of movement through the fluid, said means consisting essentially of fluid-dynamically spaced elongated depressions in the gross outer surface of at least some portion of the trailing half of the mass of said body portion, each said depression (i) being aligned on said gross outer surface within an angle not greater than 30* from said axis, (ii) having a maximum width and maximum depth less than the length thereof, and less than the radius of the circumference generated by rotation of said body portion at the location thereof, and (iii) having a greatest depth portion radially displaced with respect to a lesser depth portion thereof, said greatest depth portion being forward of the longitudinal midpoint thereof and toward the leader of said missile, whereby each said depression during said transit of said missile through a fluid creates a resultant fluid-dynamic composite force vector which lies in a line not intersecting the aforesaid longitudinal axis of said body portion but passing laterally thereto, each said line passing on the same relative lateral side of said axis.

2. The missile of claim 1 wherein said greatest depth portion of the depressions is lateral to the width midpoint of the depressions.

3. The missile claim 1 wherein said depressions are asymetrical in linear contour in radial planes perpendicular to the axis of said body portion.

4. The missile of claim 1 wherein said depressions are tear-drop shapes in outer perimeter.

5. The missile of claim 1 wherein said depressions are minute in size and a multitude of said depressions are present in the gross surface of said body portion.

6. The missile of claim 1 wherein the directional alignment of said elongated depressions is substantially parallel to said axis of rotation.

7. The missile of claim 1 wherein body portion comprises a straight shaft and the trailing end includes a groove adapted to receive a bowstring.