Roger L Ellis

US Patent:

59526017, Sep 14, 1999

Filed:

Apr 23, 1998

Appl. No.:

9/064717

Inventors:

Matthew J. Sanford - Bel Alton MD
Larry E. Crabtree - Falmouth VA
Roger L. Ellis - Fredericksburg VA
James F. Cahill - Fredericksburg VA

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

F41A 108

US Classification:

89 1706

Abstract:

A recoilless and gas-free projectile propulsion device is provided. A hol pressure vessel is sealed on a first end to an aft end of a projectile in a launch tube. The pressure vessel is further open on a second end. A propellant charge-filled pressure chamber, defined in a forward portion of the pressure vessel, has holes venting to the pressure vessel aft thereof. A piston, sealed within the pressure vessel for sliding movement therein, is spaced apart from the pressure chamber to define a volume therebetween that receives gases produced during the burning of the propellant charge via the vent holes. A pressure valve divides the volume into a forward section adjacent the pressure chamber and an aft section adjacent the piston. The pressure valve remains closed until a threshold pressure is reached in the forward section at which point the pressure valve opens to join the forward section with the aft section. A countermass is positioned between the piston and the second end of the pressure vessel.