Vehicle launch device

1. A launch device connected to an input member and an output member comprising:

a planetary gear set having a first member, a second member, and a third member; wherein an input member and an output member are operatively connectable for rotation with different ones of the members of the planetary gear set; and

a centripetal clutch operatively connecting two of the members of the planetary gear set and configured to transmit torque with a torque capacity that decreases as a difference between the speed of rotation of the output member and the speed of rotation of the input member decreases.

2. The launch device of claim 1 , wherein the input member is connected to the first member, the second member is connected with the output member, and the centripetal clutch is connected between the second member and the third member.

3. The launch device of claim 2 , wherein the first member is a carrier member, the second member is a ring gear member, and the third member is a sun gear member.

4. A launch device for a vehicle having an engine with an engine output member and a transmission with a transmission input member, the launch device comprising:

a planetary gear set having a first member, a second member, and a third member, wherein the members of the planetary gear set include a ring gear member, a carrier member, and a sun gear member;

wherein the engine output member is operatively connectable for rotation with the first member;

wherein the second member is connected for rotation with the transmission input member; and

a centripetal clutch having a drive member connected for rotation with one of the members of the planetary gear set and a driven member connected for rotation with another of the members of the planetary gear set; and wherein the centripetal clutch is configured to transmit torque from the drive member to the driven member with a torque capacity that decreases as a difference between the speed of rotation of the third member and the speed of rotation of the second member decreases; and wherein the centripetal clutch is configured to overrun when the another of the members of the planetary gear set rotates faster than the one of the members of the planetary gear set.

5. The launch device of claim 4 , wherein the one of the members of the planetary gear set is the second member and the another of the members of the planetary gear set is the third member.

6. The launch device of claim 5 , wherein the first member is the carrier member, the second member is the ring gear member, and the third member is the sun gear member.

7. The launch device of claim 5 , wherein the centripetal clutch is a first centripetal clutch, and further comprising:

a second centripetal clutch having a second drive member connected for rotation with the engine output member and a second driven member connected for rotation with the first member; and wherein the second centripetal clutch is configured to transmit torque from the second drive member to the second driven member with a torque capacity that decreases as a difference between the speed of rotation of the second drive member and the speed of rotation of the second driven member decreases; and wherein the second centripetal clutch is configured to overrun when the second driven member rotates faster than the second drive member.

8. The launch device of claim 7 , wherein the first member is the carrier member, the second member is the ring gear member, and the third member is the sun gear member.

9. The launch device of claim 4 , wherein the centripetal clutch includes:

a plurality of arms pivotably connected to the drive member; and

a plurality of springs biasing the plurality of arms toward the drive member with a biasing force predetermined to prevent engagement of the plurality of arms with the driven member when the drive member rotates below a predetermined speed of rotation.

10. A launch device for a vehicle having an engine with an engine output member and a transmission with a transmission input member, the launch device comprising:

a first set of intermeshing gears; wherein the engine output member is operatively connectable for rotation with a first gear member of the first set of intermeshing gears;

a first planetary gear set having a first member, a second member, and a third member, wherein the members of the first planetary gear set include a ring gear member, a carrier member, and a sun gear member;

wherein a second gear member of the first set of intermeshing gears is connected for one of common rotation and rotation at a predetermined ratio with respect to rotation of the first gear member of the first planetary gear set;

wherein the second member of the first planetary gear set is connected for rotation with the transmission input member;

a centripetal clutch having a drive member connected for rotation with the third member of the first planetary gear set and a driven member connected for rotation with the second member of the first planetary gear set; and wherein the centripetal clutch is configured to transmit torque from the drive member to the driven member and to the first member of the planetary gear set with a torque capacity that decreases as a difference between the speed of rotation of the third member of the first planetary gear set and the speed of rotation of the engine output member decreases; and wherein the centripetal clutch is configured to overrun when the engine output member rotates faster than the third member of the first planetary gear set.

11. The launch device of claim 10 , wherein the centripetal clutch is a first centripetal clutch, and further comprising:

a second centripetal clutch having a second drive member connected for rotation with the engine output member and a second driven member connected for rotation with the first gear member of the first set of intermeshing gears; and wherein the second centripetal clutch is configured to transmit torque from the second drive member to the second driven member with a torque capacity that decreases as a difference between the speed of rotation of the second drive member and the speed of rotation of the second driven member decreases; and wherein the second centripetal clutch is configured to overrun when the second driven member rotates faster than the second drive member.

12. The launch device of claim 10 , wherein the first set of intermeshing gears is a second planetary gear set; wherein the first gear member of the first set of intermeshing gears is a carrier member of the second planetary gear set; wherein the second member of the second set of intermeshing gears is a ring gear member of the second planetary gear set; and wherein the first set of intermeshing gears includes a sun gear member grounded to a stationary member and meshing with planet gears supported for rotation by the carrier member of the second planetary gear set.

13. The launch device of claim 12 , wherein the first member of the first planetary gear set is the ring gear member of the first planetary gear set; wherein the second member of the first planetary gear set is the carrier member of the first planetary gear set; and wherein the third member of the first planetary gear set is the sun gear member.

14. The launch device of claim 12 , wherein a thrust bearing transmits torque from the first centripetal clutch to engage the carrier member of the second planetary gear set with the carrier member of the first planetary gear set.