Releasable coupling assembly for oscillating wave lawn sprinkler

An oscillatory wave type lawn sprinkler comprising:

• an elongated base;
• a support arbor located at one end of said base;
• a motor housing located at the other end of said base;
• an elongated spray tube journaled between said motor housing and said support arbor;
• motor means including a rotationally driven drive shaft and a drive linkage coupled between said spray tube and said drive shaft for transmitting the rotational motion of said drive shaft into angularly oscillatory motion of said spray tube, said drive linkage including a drive crank coupled to said drive shaft a connnecting arm coupled to said drive crank, and a crank link coupled to said connecting arm;
• a releasable coupling assembly including an indentation formed in one of said crank link and said spray tube, a tab located on the other of said crank link and said spray tube for engaging said indentation, the one of said indentation and said tab on said spray tube being formed integrally with said spray tube, and means for permitting said spray tube to move relative to said crank link by releasably securing said tab in engagement with said indentation for normal angular oscillatory driving of said spray tube by said crank link, said securing means being disengageable from said indentation or tab whenever said spray tube is subjected to an externally applied rotational force exceeding a predetermined magnitude to permit said spray tube to rotate relative to said crank link and move independently of said drive linkage.

In an oscillating wave lawn sprinkler of the type having a spray tube, a fluid-driven motor, and a drive linkage, which includes a crank link, said linkage being coupled between the motor and the spray tube for transforming rotational motion of the motor into angularly oscillatory motion of the spray tube, the improvement comprising:

• a releasable coupling assembly for releasably coupling said drive linkage to said spray tube, said coupling assembly including:
• an indentation formed directly in said spray tube;
• a tab located on said crank link for engaging said indentation;
• and
• means for permitting said spray tube to move relative to said crank link by releasably securing said tab in engagement with said indentation for normal angular oscillatory driving of said spray tube by said crank link, said securing means including a C-shaped clamp at one end of said crank link, said tab being formed on an interior surface of said clamp, said interior surface being formed on a radius at least slightly smaller than half of the outer diameter of the spray tube so that said tab is retained in said indentation by frictional clamping force when said clamp is fastened about said spray tube, said securing means being disengagable from said indentation or tab whenever said spray tube is subjected to an externally applied rotational force exceeding a predetermined magnitude to permit said spray tube to rotate relative to said clamp and move independently of said drive linkage.