DONALD JOSEPH BUTTERWORTH
Pilots at Gln Ml Rd, Glen Mills, PA

4858075, Aug 15, 1989

Jan 30, 1987

7/008664

Donald J. Butterworth - Glen Mills PA

Bell of Pennsylvania - Philadelphia PA

H05K 114

361395

An RF shielded and electrically insulated circuit board structure comprises a first layer of shrink wrap tubing wrapped on a circuit board substrate, and a layer of an electrically conductive RF shielding material on the tubing. A second layer of shrink wrap tubing retains the electrically conductive material to the circuit board. Edge portions of the electrically conductive layer and heat shrink tubing are folded inward to prevent RF energy from the circuit board from leaking from the edges of the structure. The structure is made by wrapping a first heat shrink tubing on the circuit board to insulate and seal any wiring patterns and components thereon and shrinking the tubing by applying heat. The electrically conductive layer is located on the heat shrink tubing, and the second heat shrink tubing is wrapped on the electrically conductive layer and first tubing. Heat is applied to shrink the second tubing, and, with circuit wiring extending outward, the edge portions of the structure are folded inward to complete the structure.

4777644, Oct 11, 1988

Jun 16, 1987

7/062592

Donald J. Butterworth - Glen Mills PA
Larry Mortimer - Willingboro NJ

Bell of Pennsylvania - Conshohocken PA

H04M 124, H04M 1700

379 1

A portable tester determines an operating condition of coin relays by sensing a duration of a time period between flux conditions generated thereby. The device does not require electrical circuit connection to the relay and is thus a non-invasive testing apparatus. An annunciator provides audible and visual indications to service personnel to indicate whether the detected duration is too short, requiring one form of adjustment, too long, requiring a second form of adjustment, or within a specified range therefor, requiring no adjustment.