use the
propeller's rotation and inertial force to power the cutting action. As the offending line
enters the propeller vortex, it is wound toward the propeller hub. (NOTE: It is at this
point that, without SPURS installed, the line would wind itself tighter and tighter,
entering into the space between propeller hub and rope guard, where it can damage the oil
seals.) Instead, the line is engaged by the rotating cutter blades and delivered to
the stationary cutter blade. The sudden resistance sensed by the stationary cutter forces
a cam action which causes the blade to be pushed outward, meeting the rotating blade and
severing the obstruction. |
The cutting force increases in direct proportion to the resistance sensed
by the stationary cutter assembly. This shearing action means that the cutting blades
never actually come into contact with each other. Hydrophilic and bronze surface bearings
maintain precise cutter positioning when a resistance occurs. With each rotation the
cutters pass each other gliding on a thin lubricating film of water or within a few
thousandths of each other, thus avoiding surface wear during long passages. |
Stationary Cutter centers itself in the cutter guides as it passes through
with each revolution of the prop. |