A method for producing a bendable and twistable composite element for mechanically connecting two members, said bendable and twistable element having an elongate ternary composite middle portion, comprising filaments having a high level of mechanical strength, a thermosetting resin and a curable elastomer, the method comprising the steps of
- passing said filaments through an impregnating machine containing said thermosetting resin;
- joining together impregnated filaments thereby obtained and calibrating them by passing through a die to produce an impregnated continuous member of a desired shape;
- and cutting lengths of the shaped member;
- wherein the method further comprises the steps of
- forming a plurality of unitary layers, each unitary layer being formed by
- locating the middle portion of said cut lengths of said shaped member, each impregnated with said resin which is still in the unpolymerised state, in straight, parallel and calibrated grooves, having a section corresponding to that of said shaped member and provided in a first mould, with the two end portions of said cut lengths projecting in said first mould beyond the ends of said grooves and resting each on at least one layer of fabric of resin impregnated fibers,
- disposing onto each of said two end portions of said cut lengths at least another layer of said fabric,
- pressing and flattening said two end portions of said cut lengths between said resin-impregnated layers of fabric, and
- polymerising said resin on said impregnated cut lengths and in said layers of fabric;
- stacking a plurality of said unitary layers in a second mould to form a bundle with said middle portions of said cut lengths, and in which bundle said cut lengths of said plurality of unitary layers are suitably spaced
- disposing layers of adhesive between said layers of fabric of said stacked unitary layers, at least at one end portion of said bendable and twistable element,
- applying heat and compression to the stack thus obtained in said second mould to form at least one rigid connecting attachment end portion of the laminated type, to be secured to at least one of the two members to be connected;
- injecting elastomer in a viscous state into said bundle of said middle portions of said cut lengths, the kind and the viscosity of the particular elastomer used being selected according to the characteristics of resiliency and damping which are to be provided by the elastomer,
- curing the elastomer at a temperature and for a time appropriate to the characteristics thereof, to form said elongate ternary composite middle portion of said element and forming a depression at least at one end portion of said element at the location at which said cut lengths of said unitary layers enter between said impregnated layers of fabric and filling said depression by injecting an elastomer which is less flexible than said elastomer injected into said bundle of said middle portions of said cut lengths thereby reducing the rigidity of embedding of said cut lengths.