|
US6233336B1
|
|
Inductive coupling interface for electronic device
|
|
CA2036521A1
|
|
Intrinsically safe telephone
|
|
CA1272319A
|
|
Intrinsically safe telephone
|
|
IT7950965D0
|
|
Intraplant telephone communication system
|
|
ES486293A1
|
|
Telephone communication system (Machine-translation by Google Translate, not legally binding)
|
|
NL7908446A
|
|
Intraplant telephone communication system - has disconnect relay activated by proximity RF transmitter upon movement of handset
|
|
CA1148677A
|
|
Intraplant communication system
|
|
US4206318A
|
|
Intraplant communication system
|
|
US4113985A
|
|
Mine dial and page phone system
|
|
CA1031480A
|
|
Mine paging and telephone system
|
|
CA1004788A
|
|
Plant telephone communication system
|
|
US3909547A
|
|
Mine paging and telephone system
|
|
CA936920A
|
|
Intra-plant radio communication system
|
|
ES377345A1
|
|
Oral communication system between plants. (Machine-translation by Google Translate, not legally binding)
|
|
US3527890A
|
|
Intraplant voice communication system
|
|
US3254160A
|
|
Regulated gain telephone handset receiver amplifier
|
|
ES279732A1
|
|
A system of internal vocal communications (Machine-translation by Google Translate, not legally binding)
|
|
US3080454A
|
|
Intra-plant voice communication system
|
|
US2877302A
|
|
Telephone equipment
|
|
US2831922A
|
|
Telephone substation
|
