05034724 is referenced by 16 patents and cites 5 patents.

A wallet is disclosed which incorporates an electrical alarm circuit for signalling that e.g. a credit card has not been properly returned to its compartment in the wallet. The electrical current is transferred from compartment to compartment, and from the battery and buzzer portion, by means of contact pads and zones which come together when the wallet is closed. The need to conduct electricity through the hinge area is eliminated.

Title
Alarm device for wallets and the like
Application Number
7/302239
Publication Number
5034724
Application Date
January 26, 1989
Publication Date
July 23, 1991
Inventor
James D Tone
Upr 11 Rose St., Kitchener, Ontario
CA
Agent
Anthony Asquith & Co
IPC
G08B 13/14
View Original Source