Nathan P Cook

US Patent:

42283388, Oct 14, 1980

Filed:

Jun 8, 1978

Appl. No.:

5/913763

Inventors:

Nathan H. Cook - Cambridge MA
Krishnamoorthy Subramanian - Inkster MI

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

B23K 904

US Classification:

219 7613

Abstract:

A process for implanting a precise quantity of radioactive metal on a metal substrate such as a cutting tool or other metal part subject to wear at the area or areas where the part is expected to wear during its operation. The presence of the radioactive spot can be sensed to determine the extent of wear during use. The radioactive metal is deposited from a wire formed of a core of the radioactive metal surrounded by a sheath of metal having a high thermal and electrical conductivity relative to the core. In operation, the wire contacts the metal surface under pressure and electric current is passed through the wire in order to (1) form a pit on the tool surface, (2) weld the radioactive metal in the pit and (3) evaporate a small portion of the conductive sheath adjacent the pit. A second current then is passed through the wire to break it near the bottom of the pit, leaving a small quantity of radioactive material welded to the bottom of the pit.

US Patent:

42860261, Aug 25, 1981

Filed:

Aug 14, 1979

Appl. No.:

6/066329

Inventors:

Nathan H. Cook - Cambridge MA
Krishnamoorthy Subramanian - Inkster MI

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

B23K 3522
B32B 1502

US Classification:

428607

Abstract:

A process for implanting a precise quantity of radioactive metal on a metal substrate such as a cutting tool or other metal part subject to wear at the area or areas where the part is expected to wear during its operation. The presence of the radioactive spot can be sensed to determine the extent of wear during use. The radioactive metal is deposited from a wire formed of a core of the radioactive metal surrounded by a sheath of metal having a high thermal and electrical conductivity relative to the core. In operation, the wire contacts the metal surface under pressure and electric current is passed through the wire in order to (1) form a pit on the tool surface, (2) weld the radioactive metal in the pit and (3) evaporate a small portion of the conductive sheath adjacent the pit. A second current then is passed through the wire to break it near the bottom of the pit, leaving a small quantity of radioactive material welded to the bottom of the pit.

US Patent:

43984290, Aug 16, 1983

Filed:

May 4, 1981

Appl. No.:

6/260040

Inventors:

Nathan H. Cook - Cambridge MA
Forest J. Carignan - Bedford MA

Assignee:

Advanced Mechanical Technology, Inc. - Newton MA

International Classification:

G01L 516

US Classification:

7386204

Abstract:

A force measuring apparatus includes a platform construction on which forces may be exerted, as for example, by an individual stepping upon a top plate of the platform construction. Apparatus of this nature is commonly referred to in the art as a "Biomechanics Platform", and may include a bottom plate, a top plate deformable by forces exerted thereon and a plurality of load cell members arranged to yieldably support the top plate in spaced relation to the bottom plate. The load cells are constructed with strain ring means having strain gage elements suitably supported thereon, and the cells further include composite anchoring means for connecting the top plate with strain rings of respective load cells in a unique manner. Each of the composite anchoring means includes a compliant or elastic member which is arranged to transmit, at any given time, an entire load exerted between the top plate and its respective load cell. Also included in each composite anchoring means are retaining elements arranged to engage with a respective elastic member as well as adjacent top plate and strain ring portions.

US Patent:

40668215, Jan 3, 1978

Filed:

Jan 22, 1976

Appl. No.:

5/651269

Inventors:

Nathan Henry Cook - Cambridge MA
Bruce M. Kramer - Wantagh NY

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

C23C 1108

US Classification:

428539

Abstract:

Tungsten carbide tools are provided having improved wear properties which tools produce an improved surface finish on workpieces cut with said tools, both initially and after extended use. The tools are prepared by a process which comprises applying a coating of a Group IVB or VB metal of the Periodic Chart of the Elements over the tool, diffusing said metal into the tool and removing any excess of the metal from the surface of the tool, possibly by further diffusion of the metal into the tool. The preferred method is by gaseous decomposition of a metal halide in an atmosphere which does not contain a carbon source such as methane, used in some previous processes. The source of the carbon in the Group IVB or VB metal carbide is the carbon in the carbide tool being coated. Tools formed in accordance with the invention have wear properties such that they typically last at least four times as long as untreated tools and under most preferred conditions, as much as nine times as long as untreated tools.