Pop-up sprinkler

A sprinkler apparatus, comprising:

• a housing defining a hollow interior extending from a lower portion of the housing to an upper portion of the housing and an inlet port through which to supply a flow of liquid to the interior;
• a stem disposed at least partially within the interior of the housing, which stem is adapted to be moved between a retracted position in which the stem is disposed substantially within the interior of the housing and an extended position in which the stem extends beyond the upper portion of the housing;
• an enlarged portion of the stem defining a piston adapted to respond to the flow of liquid supplied to the interior of the housing to move the stem from the retracted position to the extended position;
• the stem defining a passageway extending from a lower portion of the stem to an upper portion of the stem;
• the lower portion of the stem defining a cylindrically-shaped exterior surface on the stem and an opening extending through the cylindrically-shaped exterior surface to the passageway through which the flow of liquid can pass from the interior of the housing into the passageway;
• a valve element in the form of a collar disposed generally concentrically over the cylindrically-shaped surface, which collar is adapted to be rotated relative to the stem and includes a portion defining a plurality of gear teeth to be used in rotating the collar;
• the collar defining an orifice adapted to be positioned in overlapping relationship with the opening in the lower portion of the stem by rotation of the collar relative to the stem;
• a shaft rotatably mounted on the housing, the shaft having a plurality of longitudinally-extending splines adapted to engage the gear teeth as the stem is moved between the retracted position and the extended position for purposes of causing the collar to rotate relative to the stem when the shaft is rotated, which shaft extends within the interior of the housing to an upper end portion of the shaft that is disposed in a position accessible from outside of the interior of the housing to enable manual rotation of the shaft.