Fin disengagement device for limiting projectile range

• US 6,540,176 B2
• Filed: 01/08/2001
• Issued: 04/01/2003
• Est. Priority Date: 01/08/2001
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Garner, James M., Watson, Jerry L., Davis, Bradford S., Newill, James F.
• Primary Examiner(s): Jordan, Charles T.
• Assistant Examiner(s): Holzen, Stephen A
• Application Number:
  US09/756,003
• Publication Number:
  US 20020088897A1
• Time in Patent Office: 813 Days
• Field of Search: 244/3.22, 244/3.23, 244/3.24, 244/3.25
• US Class Current: 244/3.24
• CPC Class Codes: F42B 10/06 Tail fins
• CPC Class Codes: F42B 10/48 Range-reducing, destabilising or braking arrangements, e.g. impact-braking arrangements; Fall-retarding means, e.g. balloons, rockets for braking or fall-retardingF42B10/34 takes precedence

Abstract

A fin disengagement device for limiting the range of a projectile uses an electronic safe and arm circuit to sense launch and spin levels. Once armed, the stored energy from the electronic safe and arm circuit is dumped into an initiator or directly to explosive bolts. The initiator ignites an energetic material to separate the fin from the projectile in-flight at a predetermined time. Alternatively, the explosive bolts separate the fin from the projectile in-flight at a predetermined time. In the embodiments using an initiator and energetic material, an opening or cavity in the rear portion of the projectile body or rod adapter acts as a pressure chamber. When enough pressure has built up from the burning of the energetic material, the front hub of the fin section expands enough to disengage the threads and separates the fin section from the projectile body.

Claims

1. A projectile, comprising:

a body section having a rear portion with external threads formed thereon and with an opening formed therein;

a fin section having internal threads formed therein, wherein the rear portion of the body section is attached to the fin section by engagement of the external threads of the body section with the internal threads of the fin section; and

means for separating the fin section from the body section while the projectile is in flight comprising a safe and arm circuit disposed in the fin section, an initiator support disposed in the opening in the rear portion of the body section, an initiator attached to the initiator support and connected to the safe and arm circuit, and energetic material disposed in the opening in the rear portion of the body section.

2. The projectile of claim 1 wherein the initiator support includes a plurality of channels formed on an exterior surface thereof such that gases produced by the energetic material flow to the threads of the fin section and the body section.

3. A projectile, comprising:

a body section having a rear portion with external threads formed thereon;

a fin section having internal threads formed therein; and

means for separating the fin section from the body section while the projectile is in flight comprising;

a rod adapter having an opening formed in a rear portion of the rod adapter and having internal threads for connection with the external threads of the body section and external threads for connection with the internal threads of the fin section; and

a safe and arm circuit disposed in the fin section, an initiator support disposed in the opening in the rear portion of the rod adapter, an initiator attached to the initiator support and connected to the safe and arm circuit, and energetic material disposed in the opening in the rear portion of the rod adapter.

4. The projectile of claim 3 wherein the initiator support includes a plurality of channels formed on an exterior surface thereof such that gases produced by the energetic material flow to the threads of the fin section and the rod adapter.

5. A projectile, comprising:

a body section having a rear portion with an opening formed therein;

a fin section attached to the rear portion of the body section; and

means for separating the fin section from the body section while the projectile is in flight comprising a plurality of electrically detonatable explosive bolts that attach the fin section to the rear portion of the body section, and an electronic safe and arm circuit disposed in the opening in the rear portion of the body section, the electronic safe and arm circuit being electrically connected to the electrically detonatable explosive bolts for detonation thereof.

6. A projectile, comprising:

a body section having a rear portion with an opening formed therein;

a fin section connected to the body section; and

means for separating the fin section from the body section while the projectile is in flight comprising a safe and arm circuit disposed in the fin section, an initiator support disposed in the opening in the rear portion of the body section, an initiator attached to the initiator support and connected to the safe and arm circuit, and energetic material disposed in the opening in the rear portion of the body section.