Method of making a helmet

A method of fabricating a helmet characterized by a hemispherical shape, the hemispherical shape having a center point and a central axis that passes through the center point, the method comprising:

• (a) providing a helmet preform subassembly comprising at least two layers of fabric wherein the at least two layers of fabric are impregnated with a polymer resin, the helmet preform subassembly having a shape comprising m arms arranged about the center point, each arm having at least one width Wi, and m=3 or 4, wherein the shape and size of the preform subassembly is determined by:
• (i) providing a series of n reference planes P1, P2, P3 . . . Pn that is each orthogonal to the central axis and describes a circular shape at the location of its intersection with the hemispherical shape;
• (ii) measuring, for each reference plane, (1) the perimeter length referred to as Hi for Pi of the circular shape, and (2) the length defined by the distance along the hemispherical shape of the arc referred to as Ai for Pi that exists between the location of the intersection of the plane therewith and the center point, wherein for a subassembly in which P1 is the closest plane to the center point A1<A2<A3< . . . <An, and H1<H2<H3< . . . <Hn;
• (iii) providing a series of n concentric reference circles C1, C2, C3 . . . Cn each of which has the same center point, wherein the radius of circle Ci is arc length Ai;
• (iv) dividing perimeter lengths H1, H2, H3 . . . Hn into m equal portions, and assigning one of the equal portions as an equally-spaced segment W1, W2, W3 . . . Wn of or each of the respective reference circles C1, C2, C3 . . . Cn;
• (v) drawing a line to connect the end points of the segments of circle length W1, W2, W3 . . . Wn to graphically represent the m arms of the preform subassembly;
• (b) stitching together side edges of the arms of the perform subassembly which are adjacent to each other to form a stitched perform subassembly;
• (c) stacking a plurality of stitched preform subassemblies to form a stack;
• and
• (d) compression molding the stack.