Electronic horn

An electronic horn comprising:

• a plate-shaped oscillator;
• a piezoelectric element configured to excite the oscillator;
• a resonator having an opening, the resonator at least partially covering one side of the oscillator and a resonance space being defined between a first side of the resonator and the oscillator;
• an intermediate element provided on a second side of the resonator;
• a first water-proofing wall extending away from the resonator in a first direction and defining a buffer chamber that is in fluid communication with the resonance space via the opening;
• at least one second water-proofing wall extending away from the resonator in the first direction;
• a cover attached to a side of the intermediate element that is opposite of the resonator in the first direction,
• wherein the cover includes:
• a central portion that projects in a second direction, which is opposite of the first direction, within a space defined by the first water-proofing wall and toward the opening of the resonator,
• a third water-proofing wall extending in the second direction into a space between the first and second water-proofing walls, and
• a fourth water-proofing wall extending in the second direction into a space between the radially-outer side of the second water-proofing wall and the intermediate element, and
• wherein:
• a first portion of a first sound passage is defined by the central portion of the cover and a radially-inward side of the first water-proofing wall and extends from the buffer chamber in the first direction to a portion of the cover that extends perpendicular to the first direction,
• a second portion of the first sound passage extends radially outwardly from the first portion of the first sound passage and is curved,
• a first portion of a second sound passage extends from the second portion of the first sound passage in the second direction and is defined by a radially-outward side of the first water-proofing wall and a radially-inward side of the third water-proofing wall,
• a second portion of the second sound passage extends radially outwardly from the first portion of the second sound passage and is curved,
• a first portion of a third sound passage extends from the second portion of the second sound passage in the second direction and is defined by a radially-outward side of the third water-proofing wall and a radially-inward side of the second water-proofing wall,
• a second portion of the third sound passage extends radially outwardly from the first portion of the third sound passage and is curved,
• a first portion of a fourth sound passage extends from the second portion of the third sound passage in the second direction and is defined by a radially-outward side of the second water-proofing wall and a radially-inward side of the intermediate element,
• a second portion of the fourth sound passage extends radially outwardly from the first portion of the fourth sound passage, is curved and contains a portion that connects to the opening of the cover,
• the first portions of the first, second, third and fourth sound passages are concentric, and
• the fourth sound passage has an opening to the exterior of the horn, the opening facing toward the first direction and being in fluid communication with an opening in the cover.