Wrap spring activated torque transfer device

A torque coupling mechanism, comprising:

• a drive member;
• driven member adapted to receive torque from said drive member;
• a clutch device for drivingly connecting said drive member and said driven member said clutch device comprising first and second hub members coaxially disposed with respect to each other and a coiled wrap spring disposed within an annular counterbore provided in said hub members, wherein said spring is fixed at one end with respect to said first hub member and selectively fixed with respect to said second hub member,
• wherein said first hub member forms part of said driven member,
• wherein said second hub member comprises a threaded region for engagement with a thread ring, and
• wherein said second hub member further comprises a splined interface for contact with a pilot clutch disc, and wherein a bias spring is interposed between said thread ring and said pilot clutch disc.

A torque coupling mechanism, comprising:

• a drive member;
• driven member adapted to receive torque from said drive member;
• a clutch device for drivingly connecting said drive member and said driven member, said clutch device comprising first and second hub members coaxially disposed with respect to each other and a coiled wrap spring disposed within an annular counterbore provided in said hub members, wherein said spring is fixed at one end with respect to said first hub member and selectively fixed with respect to said second hub member, wherein said first hub member forms part of said driven member,
• further comprising a ball ramp mechanism disposed between said drive member and said second hub member, said ball ramp mechanism comprising a pilot clutch ramp, balls, a ball separator plate, primary clutch ramp, and a thrust bearing assembly, wherein said thrust bearing assembly is disposed between said drive member and said pilot clutch ramp to provide a stiff low friction surface to interface with said pilot clutch ramp, and wherein said pilot clutch ramp and said primary clutch ramp each comprise bi-directional radial profile ramp surfaces for contact with said balls.

A torque coupling mechanism, comprising:

• a drive member;
• a driven member adapted to receive torque from said drive member;
• a clutch device for drivingly connecting said drive member and said driven member, said clutch device comprising first and second hub members coaxially disposed with respect to each other and a coiled wrap spring disposed within an annular counterbore provided in said hub members, wherein said spring is fixed at one end with respect to said first hub member and selectively fixed with respect to said second hub member,
• wherein said first hub member forms part of said driven member,
• further comprising a primary clutch pack disposed between said drive member and said first hub member, wherein said primary clutch pack comprises a plurality of alternating discs and plates, of which said discs are splined to driven member and said plates are splined to the drive member.