Torsion damping mechanism

A torsion damping mechanism adapted for torque transmitting connection between an engine driven drive of vehicle driveline and a transmission drive;

• the mechanism comprising a damper assembly and a resilient assembly;
• the damper assembly including first and second means mounted for relative rotation about a common axis for clutching coaction therebetween to dampen driveline torsionals;
• the resilient assembly interconnecting the first and second means in parallel with the clutching coaction for transmitting steady-state driveline torque between the drives and for isolating driveline torsionals;
• the improvement comprising:
• said damper assembly being a viscous damper including annular housing and clutch assemblies respectively defining said first and second means, said housing assembly including first and second radially extending sidewall members adapted to be drivingly connected at a radially outer extent to the engine driven drive, said sidewall members having mutually facing sidewall surfaces defining an annular radially extending chamber closed at its radially outer extent by means sealingly securing the sidewall members together, said clutch assembly including radially outer and inner portions, and said outer portion having oppositely facing radially extending clutch surfaces disposed in axially spaced relation from their associated sidewall surfaces for viscous clutching coaction therebetween via a viscous liquid in the chamber;
• and
• said resilient assembly including a hub member and at least two spiral wound springs, said hub member being drivingly connected to said clutch inner portion and adapted for positive driving connection with the transmission drive, and said spiral springs each having a radially outer end and a radially inner end respectively and symmetrically attached for positive drive with said housing assembly and said hub member.