摘要 |
An agitation apparatus, which is suitable for use in a cleaning head (12) of a vacuum cleaner, comprises first and second flow paths (101, 110, 102, 120). Each flow path has a resonant cavity (101, 102) and an inlet/outlet port (11 0, 120) which joins the cavity (101, 102) to the space (55) within the cleaning head (12). Generating means (200), such as a loudspeaker with a diaphragm, generates an alternating pressure wave between the ports (110, 120). Pressur e waves are emitted from a first of the ports (110) in anti-phase with the pressure waves from the second of the ports (120) and thus operating noise i s low. Due to both sides of the generating means (diaphragm) being exposed to an equal static pressure, the generating means operates more reliably. A plurality of these arrangements can be provided across the cleaning head, an d a part of the agitation apparatus, such as the driver (200), can be mounted on the main body of the vacuum cleaner.
|