Rotary sprinkler with unidirectional stepwise angular movement

A rotary sprinkler comprising:

• a stationary cylinder, one end of which is connectable to a water supply line;
• an output member rotatably mounted inside said stationary cylinder, said member having a surface, an axial direction, at least one supply duct passing therethrough and directly leading to a nozzle-carrying sprinkler head attachable to the upper end of said member, as well as a plurality of separate control ducts inside, and a plurality of ports communicating with said control ducts and leading to the outer surface of, said member, at least one port communicating with said supply duct;
• a slidable piston riding on said member and slidable in said stationary cylinder between an upper and a lower position, said slidable piston dividing said stationary cylinder into an upper chamber and a lower chamber, coupling means being provided for linking said member to said slidable piston in rotation while permitting said slidable piston one degree of freedom of stroke-like, reciprocating translatory movement relative to said member;
• a slide valve located on said member for controlling at least some of said ports for producing said reciprocating, translatory movement, and
• a set of camming means for kinematically linking said stationary cylinder and said slidable piston, whereby at least part of said translatory, reciprocating strokes of said slidable piston will produce the superposition thereupon of a stepwise, angular movement in one sense of rotation only, transmitted via said coupling means, to said member and said nozzle-carrying sprinkler head.