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US 5,703,337 AGranted
System for cancelling sound waves
AssigneeNokia Technology GmbH
InventorStefan Geisenberger
Life of this patent
Estimating the term…
Abstract
An area between a gas exhaust pipe (23) and the front side (26) of a diaphragm (14) near the magnet system (11) is closed off by means of a corrugated cover (27). The presence of the cover (27) prevents acoustic short circuits between the front side (26) and a rear side (28) of the diaphragm (14). Since furthermore the end of the gas exhaust pipe (23, 23'), which protrudes into a space (25), does not reach the end of the diaphragm (14) which is connected with a bead (31), such a loudspeaker (10) can operate at very low continuous output.
Claims7
A system for cancelling sound waves in gas exhaust streams, comprising:
- a loudspeaker (10) that comprises a magnet system (11), an oscillating system (12) formed of a diaphragm (14) and an oscillator coil (15) for oscillating with respect to the magnet system, and to a frame (13) attached to the magnet system and the diaphragm, where the magnet system (11) includes a channel (22) along an axis of symmetry of the loudspeaker (10), and
- a gas exhaust pipe, having an end from where sound-affected exhaust gases exit from the gas exhaust pipe that pass through the channel (22), the pipe situated in the channel, at least in part, in such a way that it emerges into and terminates at an end thereof within a cone-shaped space (25) formed by the diaphragm (14), wherein a gas impermeable cover (27) is connected to the diaphragm (14) and to the end of the gas exhaust pipe to form a gastight barrier across a space between the diaphragm and the end of the gas exhaust pipe.
Dependencies are inferred from the claim text.