Composite propeller blade with unitary metal ferrule and method of manufacture
OwnerJim Rustinventor
Life of this patent
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Abstract
Composite blade assembly 10 for a propeller assembly for an airplane, including unitary metal ferrule 50 attached to a fiber-reinforced composite blade 20; and a method for manufacturing blade assembly 10. Internal pressure molding includes unitary ferrule 50 as part of mold 81 and bladder 90 pressurizes composite material 31 from within. Blade 20 is retained within inner bore 53 of unitary ferrule 50 by adhesion of the epoxy matrix and by grooves 55. The method of manufacture creates a cured blade assembly 10 that requires little or no post-machining.
Claims16
A propeller blade assembly for mounting onto a propeller hub, including:
- mounting means for mounting said assembly onto the hub;
- including:
- a unitary ferrule including:
- an inner bore;
- and
- a fiber-reinforced resin composite blade for moving a fluid including:
- an airfoil portion;
- and
- a root portion attached to said inner bore of said unitary ferrule.
A propeller blade assembly for mounting onto a propeller hub, including:
- mounting means for mounting said assembly onto the hub;
- including:
- a unitary ferrule including:
- an inner bore;
- and
- a fiber-reinforced resin composite blade for moving a fluid attached to said inner bore of said unitary ferrule;
- including:
- an airfoil portion for moving air;
- said airfoil portion having a longitudinal axis;
- and
- a root portion attached to said unitary ferrule;
- said composite blade being manufactured from resin-impregnated fabric by the process of internal pressure molding using a mold and an inflatable bladder attached to a source of pressurized gas, and including a heat-curing operation;
- said root portion and said inner bore having been maintained in direct contact during the curing operation.
A method for manufacturing a propeller blade assembly including a fiber-reinforced resin composite blade having a root portion;
- and a unitary ferrule encircling the root portion, including the steps of:
- providing a segmented mold, each mold segment including an internal cavity segment for shaping a corresponding segment of the composite blade, the cavities combining when assembled to form a mold cavity;
- providing an inflatable bladder for pressurizing the mold cavity;
- providing a source of pressurized gas for inflating the bladder;
- laying up uncured composite material into the mold cavity segments to create a plurality of laid-up assemblies;
- creating a mold assembly by bringing together the mold segments with the cavity segments facing inwardly and with the bladder between the laid-up assemblies;
- providing a unitary ferrule;
- including the unitary ferrule in the mold assembly;
- inflating the bladder with gas from the pressurized gas source to compress the laid-up assemblies against the mold cavity;
- heating the mold assembly;
- opening the mold assembly;
- and
- releasing the blade assembly from the open mold.
Dependencies are inferred from the claim text.