Blade or spar
OwnerOscar Weingartinventor
Life of this patent
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Abstract
An improved elongated blade or blade spar comprises successive low-pitch circumferentially wrapped convolutions of a synthetic resin impregnated tape having elongated cut glass and substantially parallel and equal length filaments wherein successive convolutions are overlapped approximately 50% and wherein the axis of the elongated strands lie at an angle of less than 30.degree. from the elongated spar axis. Preferably, resin impregnated filamentary strands are circumferentially wrapped around the mandrel substantially parallel with the direction of the tape wrap between selected tape layers. The improved blade spar mandrel wrapping apparatus includes a split ring support for the mandrel and through which the mandrel extends. The support ring halves may be separated, moved and rejoined during the mandrel wrapping process.
Claims6
An elongated composite tapered blade or spar having a longitudinal axis extending between a root end and a tip end having any interior recess therein and tapered cross sectional dimensions from the root to the tip ends thereof, said blade or spar being subject to securement at its root end to a support and to cyclical loading while in use, comprising:
- a resin bonded mass constituting a plurality of layers of successive helically wrapped convolutions of a synthetic resin impregnated tape,
- said convolutions of varying transverse dimension thereby defining a tapered configuration to the blade or spar,
- said tape comprising elongated cut filaments lying substantially parallel and having substantially equal lengths and carried by longitudinal continuous filaments helically wound continuously through substantially the entire blade or spar
- wherein said elongated cut filaments constitute at least 95% of said tape by weight and the length of said filaments is short compared to the length of said blade or spar;
- wherein successive convolutions of said filaments are overlapped about 50% of their length and where the axis of the elongated filaments lie at an angle of less than 30 degrees from the longitudinal axis of said blade or spar;
- whereby said filaments provide resistance to bending about the longitudinal axis of said blade or spar;
- said cut filaments constituting substantially entirely the structural support element of said spar or blade.
Dependencies are inferred from the claim text.