Patent ID: 7591088

Claim:
A suction dredge system, comprising: a suction dredge head having a dredge-material intake, a dredge-material exhaust outlet, and first and second pressurized fluid inlet ports between said dredge material intake and said dredge material exhaust outlet, a pressurized fluid supply line having first and second pressurized fluid supply branches connected to said first and second inlet ports, respectively, said first and second inlet ports being selectively openable, said second inlet port being springably held normally open, said first pressurized fluid supply branch arranged to direct pressurized fluid generally toward said dredge material intake when said first inlet port is open, so that when said first inlet port is open, said fluid flows toward said dredge material intake, thereby creating a pressure at said dredge material intake, and said second pressurized fluid supply branch arranged to direct pressurized fluid generally toward said dredge material exhaust outlet when said second inlet port is open, so that when said second inlet port is open, said fluid flows toward said dredge material exhaust outlet, thereby creating a vacuum at said dredge material intake, whereby when said second pressurized fluid inlet port is open and said first pressurized fluid inlet port is closed and a blockage clogs said dredge material intake, said second pressurized fluid inlet port will be closed and said first pressurized fluid inlet port will be opened, so that said pressure at said intake will tend to dislodge said blockage from said intake.