Stephen L Callahan

US Patent:

53647050, Nov 15, 1994

Filed:

Jun 25, 1992

Appl. No.:

7/904331

Inventors:

Stephen A. Callahan - Mesa AZ

Assignee:

McDonnell Douglas Helicopter Co. - Mesa AZ

International Classification:

B32B 900

US Classification:

428601

Abstract:

A hybrid resistance card (R-Card) is manufactured using a two-step process wherein an electrically conductive ink layer and an electrically resistive ink layer are printed onto a surface, which may be either a substrate or the part on which the R-Card is to be used. The conductive ink layer is selectively applied in a pattern of shapes to electrically short out portions of the resistive ink layer, thereby permitting the R-Card to have a predetermined resistive taper across its width according to a desired resistivity curve. The resistive ink layer comprises grid-like lines bordering and separating the conductive shapes. The resistive taper is substantially continuous along the length of the R-Card, at least linearly, though if the card is designed to cover an entire part, it is substantially continuous along a plurality of directions on the card, with the tapers being designed to round into one another. The inventive process permits much greater uniformity and predictability of result, as well as producing a much more versatile card, and is also much less expensive than currently employed processes.

US Patent:

54941806, Feb 27, 1996

Filed:

Sep 26, 1994

Appl. No.:

8/312282

Inventors:

Stephen A. Callahan - Mesa AZ

Assignee:

McDonnell Douglas Helicopter Company - Mesa AZ

International Classification:

H01C 1010

US Classification:

216 16

Abstract:

A hybrid resistance card (R-Card) is manufactured using a two-step process wherein an electrically conductive ink layer and an electrically resistive ink layer are printed onto a surface, which may be either a substrate or the part on which the R-Card is to be used. The conductive ink layer is selectively applied in a pattern of shapes to electrically short out portions of the resistive ink layer, thereby permitting the R-Card to have a predetermined resistive taper across its width according to a desired resistivity curve. The resistive ink layer comprises grid-like lines bordering and separating the conductive shapes. The resistive taper is substantially continuous along the length of the R-Card, at least linearly, though if the card is designed to cover an entire part, it is substantially continuous along a plurality of directions on the card, with the tapers being designed to round into one another. The inventive process permits much greater uniformity and predictability of result, as well as producing a much more versatile card, and is also much less expensive than currently employed processes.