Oscillating sprinkler

An improved sprinkler of the type having a nozzle which is rotatable about an axis of rotation, a reversible drive means for rotating the nozzle about its rotational axis in opposed first and second directions, wherein the drive means includes a driven gear nonrotatably fixed to the nozzle, a undirectional output shaft, and a gear train coupled to the output shaft having first and second final drive gears at each end thereof which normally rotate reversely relative to one another and which are alternately engageable with the driven gear for achieving the opposed directions of nozzle movement, wherein the improvement relates to the gear train and comprises:

• (a) a first gear set defined by a portion of the gear train at one end thereof and including at least one of the final drive gears;
• (b) a first pivot arm for carrying the first gear set for a swinging motion about a pivot axis to selectively engage the final drive gear therein with the driven gear;
• (c) a second gear set defined by a portion of the gear train at the other end thereof including at least the other final drive gear;
• (d) a second pivot arm for carrying the second gear set for a swinging motion about a pivot axis to selectively engage the final drive gear therein with the driven gear;
• and
• (e) wherein the number of gears in each gear set is selected in conjunction with the direction of pivoting of the corresponding pivot arm such that the rotation induced on each final drive gear by the swinging of the corresponding pivot arm as each final drive gear disengages the driven gear is counter to the normal rotation of each final drive gear caused by rotation of the gear train, thereby allowing approximately the same force to disengage each final drive gear from the driven gear.