Whistle
US6698377B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1999 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Jan 12, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01M31/004
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A dog whistle comprises a body formed in two parts (2,3) and provided with a mouthpiece (4) which communicates through an air passage (10) with a sound chamber (5) having a vent (6) provided with an air splitter (9), the air passage containing a ramp (8) which directs the airflow produced by blowing the whistle into the sound chamber and towards the air splitter which thereby produces a whistling sound. The chamber produces sound having a narrow frequency bandwidth lying in the range 400 to 800 Hertz, preferably about 400 Hertz. The diameter of the sound chamber is within about 10% of its length and the ramp is at an angle of less than 8°, preferably 4° 30′, to the axis of the air passage. The angle of the surface of the air splitter is greater than 38° preferably 55°.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.