Patent ID: 7794354

Claim:
A variable speed transmission comprising: a drive shaft operably coupled to a prime mover; a first planetary gearset rotatably coupled to the drive shaft, the first planetary gearset including a first sun gear, a first plurality of planetary gears drivenly connected to the drive shaft and disposed in an intermeshing relationship with the first sun gear, and a first ring gear having a first interior gear surface meshing with the first plurality of planetary gears and a first exterior gear surface; an intermediary shaft rotatably coupled to the first sun gear; a secondary shaft axially aligned and spaced with respect to the intermediary shaft; a first spur gear rotatably mounted to the secondary shaft, the first spur gear being meshed for opposing motion with the first exterior gear surface; a second spur gear rotatably mounted to the secondary shaft, the second spur gear located at an end opposite the first spur gear; a second planetary gearset rotatably coupled to the intermediary shaft, the second planetary gearset including a second sun gear drivenly connected for concurrent rotation to the intermediary shaft, a second plurality of planetary gears disposed in an intermeshing relationship with the second sun gear, and a second ring gear having a second interior gear surface meshing with the plurality of planetary gears and a second exterior gear surface meshing with the second spur gear; a driven shaft rotatably coupled to the second plurality of planetary gears, the driven shaft operably coupled to a rotary load; a first clutch-brake assembly coupled to the intermediary shaft, the first clutch-brake assembly operatively cooperating with the intermediary shaft to selectively hold the intermediary shaft stationary; and a second clutch-brake assembly coupled to the secondary shaft, the second clutch-brake assembly operatively cooperating with the secondary shaft to selectively hold the secondary shaft stationary.