Views: 0 Author: Site Editor Publish Time: 2023-03-30 Origin: Site
An impact sprinkler (sometimes called a pulse sprinkler) is an irrigation sprinkler in which the head,under the force of outgoing water, moves in a circle, rotating on a bearing at the top of its threaded connection nut.It was invented by Orton Englehart in 1933 and soon became widely used. Many impact sprinklers are still in use, although in many cases it has been replaced by the gear-driven "rotor head".
Development
The original horizontal-acting impact-driven sprinkler was invented in 1933 and patented in 1935 by Orton Englehart, a citrus grower in Glendora, California.He later sold it to Clem and Mary La Fetra who manufactured and sold it under the Rain Bird brand.
Design and operation 
The sprinkler head pivots on bearings on top of its threaded coupling nut.The head is propelled in a circular motion by outflowing hydraulic power, with at least one arm protruding from the head.The sprinkler arm is repeatedly pushed back into the water flow by a spring.The impact of the arm against the water stream disperses and slightly redirects the water flow, creating an even watering area around the sprinkler.Some full-circle impact heads have a second, short-distance, opposing "spray" nozzle (see photo) that complements the close watering coverage provided by the quick "return cycle" on partial-round heads.By adjusting the position of the restriction ring, the water flow can be directed from a full circle pattern to one with less coverage.These restraint collars are fully adjustable by turning with your fingers to achieve the desired coverage area.The uninterrupted flow path of the impact head makes it less susceptible to damage and clogging by dirt and sand in the water.Therefore, they are suitable for systems fed by well water.A defining characteristic of impact heads is that they almost always have external pipe threads, as opposed to the internal threads on almost all other sprinkler types.Sprinkler heads were originally made of metal. Since the 1970's they are also made of thermoplastic for corrosion resistance.
Usage
The impact sprinkler has a long spraying radius and uniform water distribution,which reproduces the effect of natural rainfall.The device provides an above-ground alternative to furrow irrigation, where trenches are dug between rows of crops and submerged.
Variations
An underground pop-up version of the impact sprinkler was introduced as a way to avoid the problem of having to carefully and time consumingly mow around overground sprinkler heads.When not in operation, these sprinklers disappear out of sight below turf level. Although these variants provide regular convenience, malfunctioning sprinkler heads that fail to recede may become damaged by an inattentive landscaper mowing over them.Although largely replaced by gear-driven "rotor heads" by the 1990s, impact sprinklers still have many advantages, including uniformity of coverage, sand and grit resistance, and operation at lower water pressures.
