Composite drive shafts

A drive shaft for selectively connecting a drive input to an output, said drive shaft comprising:

• a tubular portion;
• a first diaphragm member;
• a second diaphragm member displaced axially along the shaft from the first diaphragm member, said first and second diaphragm members each being formed with two axial ends and at least one undulation extending radially of said ends, and said at least one undulation being intermediate said ends, and the tubular portion connecting said first and second diaphragm members, said first and second diaphragm members and said tubular portion being formed of fiber-reinforced polymer matrix composites, and said first and second diaphragm members connected to first and second axial ends of said tubular portion through a mechanical connection at joints;
• wherein said mechanical connection receives reinforcement;
• and
• wherein said reinforcement includes teeth on said first and second diaphragms interfitting with teeth at said axial ends of said tubular portion.