| 摘要 |
A rotary sprinkler of the kind wherein an outlet nozzle (2) having an integrally formed impeller element (3) is adapted to be driven by a drive ball (11) located within a drive ball enclosure (4) wherein a first major axial portion (6a) of the side wall (6) extends from the base wall (5) of the enclosure (4) to an intermediate peripheral position (8) thereof and defines a first angle alpha 1 with respect to a normal to the base wall (5) whilst a second minor axial portion (6b) of the side wall (6) extends from the intermediate peripheral position (8) to an edge rim (9) of the enclosure (4) and defines a second angle alpha 2 with respect to a normal to the base wall (5), alpha 2 being substantially greater than alpha 1, the impeller element (3) being spaced from the intermediate peripheral position (8) by a distance which is not substantially less than one half the diameter of the drive ball. <IMAGE> |
