FR846812A - Improvements to sound and ultrasonic signaling devices with a directive effect - Google Patents

Improvements to sound and ultrasonic signaling devices with a directive effect

Info

Publication number
FR846812A
FR846812A FR846812DA FR846812A FR 846812 A FR846812 A FR 846812A FR 846812D A FR846812D A FR 846812DA FR 846812 A FR846812 A FR 846812A
Authority
FR
France
Prior art keywords
sound
signaling devices
directive effect
ultrasonic signaling
ultrasonic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
Other languages
French (fr)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thales SA
Original Assignee
CSF Compagnie Generale de Telegraphie sans Fil SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CSF Compagnie Generale de Telegraphie sans Fil SA filed Critical CSF Compagnie Generale de Telegraphie sans Fil SA
Application granted granted Critical
Publication of FR846812A publication Critical patent/FR846812A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/72—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using ultrasonic, sonic or infrasonic waves
FR846812D 1938-06-01 1938-06-01 Improvements to sound and ultrasonic signaling devices with a directive effect Expired FR846812A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR846812T 1938-06-01

Publications (1)

Publication Number Publication Date
FR846812A true FR846812A (en) 1939-09-26

Family

ID=9313524

Family Applications (1)

Application Number Title Priority Date Filing Date
FR846812D Expired FR846812A (en) 1938-06-01 1938-06-01 Improvements to sound and ultrasonic signaling devices with a directive effect

Country Status (1)

Country Link
FR (1) FR846812A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2421026A (en) * 1943-07-08 1947-05-27 Bell Telephone Labor Inc Delay device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2421026A (en) * 1943-07-08 1947-05-27 Bell Telephone Labor Inc Delay device

Similar Documents

Publication Publication Date Title
FR845402A (en) Advanced training in electrical transmission devices
FR57643E (en) Improvements to manometric devices
FR846812A (en) Improvements to sound and ultrasonic signaling devices with a directive effect
FR1068313A (en) Improvements to light signaling devices for cycles and the like
FR971517A (en) Improvements to acoustic damping devices
FR876914A (en) Improvements to coupling devices
FR854848A (en) Improvements to signaling devices
FR860811A (en) Improvements to railway signaling devices
FR839085A (en) Improvements to underwater signaling devices
FR755576A (en) Improvements to sound signaling devices
FR859608A (en) Improvements to signaling or advertising devices
FR867849A (en) Acoustic devices
FR879824A (en) Improvements to sound emitting and reproducing devices
FR919497A (en) Improvement in underwater signaling devices
FR850058A (en) Improvements in ultra-short wave emitting devices
FR848414A (en) Improvements to television transmitting devices
FR951345A (en) Improvements to railway signaling devices
FR950713A (en) Improvements to refrigeration devices
FR861021A (en) Improvements to watertight closing devices
FR862885A (en) Improvement in signaling devices of 25 m / m
FR868847A (en) Enhancements to duplex television devices
FR867194A (en) Improvements to braking devices
FR867164A (en) Improvements to carburettor devices
FR737461A (en) Improvements to echo sounding and underwater signaling devices
FR48768E (en) Improvements in friction training devices