US 9,808,797 B2
Resistance analytical furnace
Joshua N. Wetzel, Benton Harbor, MI (US); and Gordon C. Ford, St. Joseph, MI (US)
Assigned to Leco Corporation, St. Joseph, MI (US)
Filed by Leco Corporation, St. Joseph, MI (US)
Filed on Jun. 18, 2013, as Appl. No. 13/920,575.
Claims priority of provisional application 61/661,595, filed on Jun. 19, 2012.
Prior Publication US 2013/0334198 A1, Dec. 19, 2013
Int. Cl. B01L 3/04 (2006.01); G01N 31/12 (2006.01)
CPC B01L 3/04 (2013.01) [G01N 31/12 (2013.01)] 4 Claims
OG exemplary drawing
 
1. An electrode assembly for a resistance analytical furnace comprising:
a cylindrical upper electrode including a central axially extending aperture configured for admission of a sample into a crucible, an enlarged cylindrical area below said central axially extending aperture, and a funnel-shaped lower end configured to receive a pedestal of a lower electrode;
the lower electrode including said pedestal configured to support the crucible thereon; said pedestal shaped to be raised into sealable engagement within said funnel-shaped lower end of said upper electrode; said lower electrode including a bottom with an upwardly extending truncated conical recess, a cooling water inlet, and a cooling water outlet communicating with said truncated conical recess, wherein said pedestal of said lower electrode includes a center threaded projection which receives a threaded lower electrode tip, said threaded lower electrode tip which is generally cup-shaped with internal threads which threadably mate with said threaded projection on said lower electrode, wherein said threaded lower electrode tip comprises an alloy of tungsten and copper, and wherein said threaded lower electrode tip includes a centered circular upward projection shaped to extend within a circular recess in the bottom of the crucible;
a nozzle positioned in said lower electrode and coupled to said water inlet, said nozzle having an exit end spaced close to an inside surface of said truncated conical recess for projecting cooling water toward said pedestal of said lower electrode; and
further including an upper electrode outer jacket surrounding said upper electrode, wherein said upper electrode includes cooling fins and said jacket surrounds said fins, said outer jacket including a cooling water inlet and a cooling water outlet for receiving water for cooling said upper electrode.