Process and apparatus for manufacturing axi-symmetrical three-dimensional structures

A process for manufacturing a three-dimensional axi-symmetrical and non-cylindrical structure constituted by superposed and interbonded layers of fibrous material comprising the steps of:

• delivering onto a rotating mandrel having an axi-symmetrical and non-cylindrical profile corresponding to that of the structure to be manufactured a tape of a fibrous material having a width that is several times less than the length of the generatrix of the said structure;
• winding the tape over the mandrel to form superposed layers in such a way that each of the layers is constituted by plural, successive turns of the tape of fibrous material;
• simultaneously with said winding step, simultaneously bonding the layers together by successively needling their constitutive turns onto the mandrel and onto the previously formed layers simultaneously as the tape is being delivered and wound onto the mandrel and onto the previously formed layers;
• and
• at the end of the winding and bonding of each layer, moving apart said mandrel said assembly of needles relatively by a distance equal to the thickness of a needled layer to provide a constant needling depth during the whole manufacturing process.

An apparatus for manufacturing a three-dimensional, axis-symmetrical and non-cylindrical structure constituted as superposed layers of fibrous material bonded together, comprising:

• a rotary mandrel having a three-dimensional axi-symmetrical and non-cylindrical profile corresponding to that of the structure to be manufactured;
• supply means for delivering a tape of fibrous material onto said mandrel in order to so form thereon said superposed layers as plural, successive turns of said tape;
• an assembly of needles extending over a length substantially equal to the width of said tape;
• first driving means for so moving said assembly of needles and to said mandrel relatively to each other as to allow the needles to penetrate perpendicularly to the tape at the location where said tape is superposed onto the mandrel and onto the previously formed layer;
• and
• second driving means for so moving said assembly of needles and to said mandrel relatively to each other as to trace along a locus line reproducing a generatrix of the surface of the mandrel and of the structure being manufactured.

A three-dimensional, axi-symmetrical and non-cylindrical structure constituted by superposed and interbonded layers of fibrous material produced by the process of delivering onto a rotating mandrel having an axi-symmetrical and non-cylindrical profile corresponding to that of the structure to be manufactured a tape of the fibrous material having a width that is several times less than the length of the generatrix of said structure produced by the steps of:

• winding the tape over the mandrel to form superposed layers in such a way that each of the layers is constituted by plural, successive turns of the tape of the fibrous material;
• simultaneously with said winding step, interbonding the layers together by successively needling their constitutive turns at the location where the tape is sequentially delivered onto the mandrel and onto the previously formed layer to form a three-dimensional, axis-symmetrical and non-cylindrical structure;
• and
• removing said structure off of said mandrel after said interbonding step is completed.

A three-dimensional axi-symmetrical and non-cylindrical structure constituted by superposed and interbonded layers of fibrous material manufactured produced by the steps of:

• delivering onto a rotating mandrel having an axi-symmetrical and non-cylindrical profile corresponding to that of the structure to be manufactured a tape of a fibrous material having a width that is several times less than the length of a generatrix of a structure;
• winding the tape over the mandrel to form superposed layers in such a way that each of the layers is constituted by plural, successive turns of the tape of the fibrous material;
• simultaneously with said winding step, interbonding the layers together by successively needling their constitutive turns over the width of the layers as the tape is delivered onto the mandrel and onto the previously formed layer to sequentially form said structure;
• at the end of the winding and bonding of each layer, relatively moving apart said mandrel and said assembly of needles by a distance equal to the thickness of a needled layer to provide a constant needling depth;
• and
• removing the structure from the mandrel after a predetermined number of layers has been built up.