| 摘要 |
<p>A swimming pool cleaner has a body (10) which defines a liquid inlet (12) and an outlet (18) which is connected via a hose to a source of suction. A throat (22) between the inlet (12) and the outlet (18) defines a region of reduced cross-sectional area, causing a zone of low pressure as liquid flows through the throat (22). A valve element (34) in the form of a cylindrical shuttle is located in a bore (30) which intersects the throat (22), and which can move into the throat (22) to block it intermittently. An auxiliary suction passage (38) connects the rear of the bore (30) to the outlet (18), so that suction is applied to both ends of the shuttle, causing it to reciprocate in the bore (30), periodically obstructing the flow of liquid through the throat (22). This causes the cleaner to move across the submerged surface. The design of the cleaner makes it resistant to jamming due to objects being trapped between the valve element (34) and the throat (22). <IMAGE></p> |
