Telescoping pop-up sprinkler

A telescoping pop-up sprinkler connectable with a source of pressurized fluid, the telescoping pop-up sprinkler head comprising:

• a tubular main body with an upper end and a lower connector end, the upper end having external threads, and the lower connector end being adapted to receive pressurized fluid, the tubular main body having an inner surface defining a plurality of internal ribs extending longitudinally in the tubular body, and
• a telescoping piston assembly disposed in the tubular body, the telescoping piston assembly including a primary piston and a secondary piston engaged together in telescoping, sliding relationship;
• the primary piston having a tubular body with an upper end and a lower end, the upper end being internally threaded, and the lower end having a retaining flange, and a primary spring disposed over the tubular body of the primary piston;
• the secondary piston having a tubular body with an upper end and a lower end, and the lower end having a retaining flange, and a secondary spring disposed over the tubular body of the secondary piston between the retaining flange of the tubular body of the secondary piston and the annular internal stop of the tubular body of the primary piston, the retaining flange of the lower end of the secondary piston including a plurality of radial slots adapted to interfit with the plurality of internal ribs of the tubular body of the primary piston;
• and
• a ratchet member disposed over the lower end of the primary piston between the primary spring and the retaining flange, wherein said ratchet member engages said plurality of internal ribs of said tubular main body, and wherein the retaining flange of the primary piston has an upper surface including a plurality of detents that interact with said ratchet member.