David F Caldwell

US Patent:

40994775, Jul 11, 1978

Filed:

Jul 14, 1976

Appl. No.:

5/705090

Inventors:

David W. Caldwell - Plant City FL

International Classification:

B63B 126

US Classification:

114281

Abstract:

An engine powered water craft comprising a hull including a pair of spaced apart hull elements extending rearwardly therefrom configured to support the craft on the water in combination with a twin rudder system for directional control. The hull further comprises an upper and lower foil extending between the hull elements. The twin rudder system comprises a pair of rudders each including a substantially vertical rudder element having a super cavitating foil element attached to the outer side thereof. The super cavitating foil element comprises a knife-like member extending upwardly at an angle from the vertical rudder element. To counteract engine torque, the rudders are vertically offset relative to each other.

US Patent:

20220213575, Jul 7, 2022

Filed:

Mar 26, 2022

Appl. No.:

17/705304

Inventors:

- Thonotosassa FL, US
David W. Caldwell - Thonotosassa FL, US

International Classification:

C22B 11/06
C22B 11/00
B22F 9/24
C22B 3/22
B22F 9/08

Abstract:

A method, and systems in which such method may be practiced, allow for the separation of elemental metals from metal alloy. A metal alloy is atomized to form metal alloy particulates. The metal alloy particulates are exposed to an oxidizing agent, such as chlorine gas in the presence of a salt, such as NaCl, an acid, such as HCl, and water. The resulting solution may be filtered to remove particulates, reduced, filtered, reduced, filtered, and so on. In aspects, the method is used to refine gold alloy by oxidation of elemental sponge gold to gold chloride followed by reduction to pure elemental gold.