Composite aircraft propeller blade
First Claim
1. A composite aircraft propeller blade adapted to provide for a smooth transfer of centrifugal and bending forces to a propeller hub member, said propeller blade comprising a rigid base retention plug having a radially inner end surface, a core of spacer material extending outwardly from said base plug and having opposite side surfaces converging together, a series of overlapping plies of resin-bonded fibrous plastics material overlying each of said side surfaces of said core, each of said plies including substantially parallel reinforcing fibers, a resin-bonded outer covering on said overlapping plies and forming the outer surface of said blade, said resin-bonded overlapping plies and outer covering forming leading and trailing blade edge portions projecting substantially forwardly and rearwardly from said base plug, a first portion of said plies and corresponding said reinforcing fibers on both of said side surfaces of said core extending inwardly around said inner end surface of said base plug and being bonded to said inner end surface, and means for securing said base plug to the hub member.
7 Assignments
0 Petitions
Accused Products
Abstract
A generally flat core of foam material extends outwardly from a wedge-shaped metal base plug, and the core is covered with overlapping plies of resin-bonded plastics materials having unidirectional fibers. The plies are covered by outer layers or skins of resin-bonded woven fabric plastics materials. The fibers of the inner plies are orientated at positive and negative acute angles relative to the longitudinal axis of the blade to provide the blade with predetermined torsional stiffness, and the fibers of the outer plies extend generally parallel to the axis and wrap around the base plug in an interleaving manner to provide high stiffness and strength to bending forces. Some of the plies extending around the base plug receive metal shell elements, and the shell elements engage propeller hub lip portions which cooperate to define an under-cut recess and clamp the plies to the base plug.
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Citations
31 Claims
- 1. A composite aircraft propeller blade adapted to provide for a smooth transfer of centrifugal and bending forces to a propeller hub member, said propeller blade comprising a rigid base retention plug having a radially inner end surface, a core of spacer material extending outwardly from said base plug and having opposite side surfaces converging together, a series of overlapping plies of resin-bonded fibrous plastics material overlying each of said side surfaces of said core, each of said plies including substantially parallel reinforcing fibers, a resin-bonded outer covering on said overlapping plies and forming the outer surface of said blade, said resin-bonded overlapping plies and outer covering forming leading and trailing blade edge portions projecting substantially forwardly and rearwardly from said base plug, a first portion of said plies and corresponding said reinforcing fibers on both of said side surfaces of said core extending inwardly around said inner end surface of said base plug and being bonded to said inner end surface, and means for securing said base plug to the hub member.
- 16. A composite aircraft propeller blade adapted to provide for a smooth transfer of centrifugal and bending forces to a propeller hub member defining an undercut recess for receiving a base portion of the blade, said propeller blade comprising a rigid base retention plug having a radially inner end surface, a core of spacer material extending outwardly from said base plug and having opposite side surfaces converging together, a series of overlapping plies of resin-bonded fibrous plastics material overlying each of said side surfaces of said core, each of said plies including substantially parallel reinforcing fibers, a resin-bonded outer covering on said overlapping plies and forming the outer surface of said blade, said resin-bonded overlapping plies and outer covering forming leading and trailing blade edge portions projecting substantially forwardly and rearwardly from said base plug, a first portion of said plies and corresponding said reinforcing fibers on both of said side surfaces of said core including inner edge portions extending inwardly around said base plug and overlying said inner end surface of said base plug, said edge portions of said plies extending from one side of said core being interleaved with said edge portions of said plies extending from the other side of said core and being bonded to said inner end surface, and means for securing said base plug within the recess of the hub member.
- 24. A composite aircraft propeller blade adapted to provide for a smooth transfer of centrifugal and bending forces to a propeller hub member, said propeller blade comprising a rigid base retention plug having an inner end surface, a core of spacer material extending outwardly from said base plug and having opposite side surfaces converging together, a series of overlapping plies of resin-bonded fibrous plastics material overlying each of said side surfaces of said core, each of said plies including substantially parallel reinforcing fibers, a resin-bonded outer covering on said overlapping plies and forming the outer surface of said blade, said resin-bonded overlapping plies and outer covering forming leading and trailing blade edge portions projecting substantially forwardly and rearwardly from said base plug, a first portion of said plies on both of said side surfaces of said core having said fibers orientated at substantial angles with respect to a longitudinal axis of said blade to provide said blade with substantial torsional stiffness relative to the hub member, a second portion of said plies overlying said first portion of said plies on both of said side surfaces of said core and having said fibers orientated generally parallel with respect to said longitudinal axis to provide the blade with substantial bending stiffness relative to the hub member, said second portion of said plies and corresponding said fibers having inner portions extending inwardly around said base plug and overlying said inner end surface of said base plug and being bonded to said inner end surface, and means for securing said base plug to the hub member.
Specification