DK37127C
(en )
1927-02-14
Electrostatic Telephone and Microphone, especially a Speaker.
FR601399A
(en )
1926-03-01
Electrostatic telephone, microphone and especially loudspeaker
CH119082A
(en )
1927-04-01
Pavilion for telephone headsets and similar devices.
ES94680A1
(en )
1926-01-16
An electrostatic phone and microphone, especially a speaker.
ES92786A2
(en )
1925-12-16
Improvement in the speakers of the talking machines, loudspeakers of wireless telephony and other similar devices.
DK35869C
(en )
1926-04-12
Earpiece for Telephones and similar Devices.
ES91544A1
(en )
1925-01-16
Improvement in the speakers of the talking machines, loudspeakers of wireless telephony and other similar devices.
DK38669C
(en )
1928-04-16
Telephone (Speaker), Microphone or similar Device.
DK39202C
(en )
1928-09-03
Speaker for Wireless Telephony.
DK35837C
(en )
1926-04-06
Electrostatic Microphone.
DK41952C
(en )
1930-03-31
Electrodynamic Microphone, Speaker and the like.
ES89064A1
(en )
1924-07-01
Improvements in loudspeakers or speakers for wireless telephony.
ES89063A1
(en )
1924-07-01
Improvements in loudspeakers or speakers for wireless telephony.
ES89065A1
(en )
1924-06-16
Improvements in loudspeakers or speakers for wireless telephony.
ES94935A1
(en )
1926-01-01
Installation in microphone and telephone devices.
DK38629C
(en )
1928-04-02
Microphone.
DK40546C
(en )
1929-07-29
Telephone.
AT109111B
(en )
1928-03-26
Telephone.
AT104322B
(en )
1926-10-11
Telephone.
ES92225A1
(en )
1925-07-01
An over-the-table telephone station.
FR32665E
(en )
1928-02-15
Loud speaker
FR606696A
(en )
1926-06-18
Loud speaker
DK41102C
(en )
1929-11-18
Speaker.
FR620329A
(en )
1927-04-20
Loudspeaker telephone receiver
ES94499A1
(en )
1925-11-01
A portable talking machine.