Patent ID: 8500321

Claim:
In a collapsible circulation system for a body of water such as contained in an enclosed water tank having side and top walls and a floor with the top wall having a relatively small access opening to receive the collapsed circulation system therethrough, the circulation system having a distribution dish, draft tube depending downwardly from said distribution dish to an inlet, and an impeller positioned to draw water up the draft tube from the inlet thereof to the distribution dish, the circulation system further including at least three, elongated flotation arms extending between respective inner end portions and outer end portions along respective longitudinal first axes, the inner end portions of said flotation arms being respectively mounted adjacent the distribution dish for pivotal movement about respective substantially horizontal second axes to collapsed positions extending substantially vertically downwardly along and outside of said draft tube, the improvement wherein the outer end portion of at least one flotation arm is tapered to thereby create a force on the flotation arm as the flotation arm is lowered into the water in the tank to move the flotation arm about the pivotal axis thereof from said collapsed position extending vertically downwardly along and outside of said draft tube upwardly toward a deployed position on the surface of said body of water extending substantially horizontally and radially outwardly of said distribution dish to support said dish, draft tube, and impeller wherein the longitudinal first axis of said one elongated flotation arm extends substantially vertically downwardly from said inner end portion in said collapsed position and the tapered outer end portion of said one flotation arm in said collapsed position includes an inner, first surface inclined substantially 45 degrees from the horizontal upwardly and inwardly toward said draft tube and said tapered outer end portion of said one flotation arm in said collapsed position further includes an outer, second surface extending substantially vertically upwardly and forming an acute angle of substantially 45 degrees with said inner, first surface.