James D Cahill

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.

US Patent:

60669675, May 23, 2000

Filed:

Feb 6, 1998

Appl. No.:

9/019551

Inventors:

James P. Cahill - Alexandria VA
William M. Markowitz - Arlington VA

Assignee:

Sensytech, Inc. - Newington VA

International Classification:

G06F 102
H04L 2720

US Classification:

327107

Abstract:

An improved circuit and technique for obtaining phase-coherent synthesis using a direct digital synthesizer (DDS). In the phase-coherent frequency synthesis device of the invention, a computational engine constructed from a large programmable gate array, a digital signal processing microprocessor, or a number of discrete digital logic blocks generates information sent to the DDS for generating an output frequency,. function. sub. out, which is in phase with all previous outputs of the device at the same frequency.

US Patent:

20140130601, May 15, 2014

Filed:

Jun 18, 2013

Appl. No.:

13/920570

Inventors:

- Adelphi MD, US
Olukayode Okusaga - College Park MD, US
James P Cahill - College Park MD, US

International Classification:

G01N 29/24

US Classification:

73655

Abstract:

A method and system comprising: