FR489874A - Improvements to electric sirens - Google Patents

Improvements to electric sirens

Info

Publication number
FR489874A
FR489874A FR489874DA FR489874A FR 489874 A FR489874 A FR 489874A FR 489874D A FR489874D A FR 489874DA FR 489874 A FR489874 A FR 489874A
Authority
FR
France
Prior art keywords
sirens
electric
electric sirens
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.)
ABB Norden Holding AB
Original Assignee
ASEA AB
Allmanna Svenska Elektriska AB
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 ASEA AB, Allmanna Svenska Elektriska AB filed Critical ASEA AB
Application granted granted Critical
Publication of FR489874A publication Critical patent/FR489874A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
    • G10K9/12—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated
    • G10K9/13—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers electrically operated using electromagnetic driving means

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
FR489874D 1917-05-11 1918-04-25 Improvements to electric sirens Expired FR489874A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE489874X 1917-05-11

Publications (1)

Publication Number Publication Date
FR489874A true FR489874A (en) 1919-03-19

Family

ID=1526069

Family Applications (1)

Application Number Title Priority Date Filing Date
FR489874D Expired FR489874A (en) 1917-05-11 1918-04-25 Improvements to electric sirens

Country Status (1)

Country Link
FR (1) FR489874A (en)

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