Apparatus for multiple layer tubular braiding

In an apparatus for producing multi-layer tubular braided structures, the combination comprising:

• means defining a plurality of generally concentric pairs of serpentine, intersecting bobbin carrier-guiding tracks;
• and
• a plurality of bobbin carrier driving gear groups, each driving gear group being operatively associated with a corresponding pair of tracks, and wherein adjacent gear groups are interconnected at a plurality of bobbin carrier crossover points, in which:
• a group of bobbin carriers is circulatable exclusively along one track of each pair of tracks;
• a group of bobbin carriers is circulatable exclusively., via said crossover points, along at least portions of the other tracks of different pairs of tracks,
• the plurality of pairs of tracks comprises two pairs of tracks, said corresponding driving gear groups meshing at four equally spaced crossover points,
• the four crossover points define adjacent quadrants of said pairs of tracks;
• a first group of bobbin carriers is circulatable exclusively along the entire length of one track of one of the pairs of tracks;
• a second group of bobbin carriers is circulatable exclusively along the entire length of one track of the other of said pairs of tracks;
• and
• third, fourth, fifth and sixth groups of bobbin carriers are circulatable exclusively via said crossover points along the other tracks of said pairs of tracks within said quadrants thereof.