摘要 |
<p>Flexible valves principally (although not necessarily exclusively) for automatic swimming pool cleaners are addressed. The valves have generally parabolic closure regions and do not present linear transverse cross-sections to water flowing through them. The closure regions may extend substantially below the transverse center lines of the valves, which additionally may include teeth at or near hinges of the closure regions. Including the hinges reduces likelihood of undesired wear at or near the outlets of the valves.</p> |