Patent ID: 8919224

Claim:
A drive apparatus, comprising: a variable drive mechanism disposed in a housing and comprising an output shaft; a gear train disposed in the housing and driven by the output shaft, the gear train comprising at least a first transmission gear and a second transmission gear; an axle disposed in the housing and having a first axis of rotation, wherein at least one end of the axle extends outside the housing and the axle is engaged to and driven by the second transmission gear; a brake mechanism disposed in the housing and comprising a brake surface formed on an internal circumference of the second transmission gear, a first brake shoe and a second brake shoe, each brake shoe having a brake pad in proximity to the brake surface of the second transmission gear, and a cam engaged to a first end of the first brake shoe and a first end of the second brake shoe; and a brake actuation shaft connected to the cam and having a second axis of rotation, whereby rotation of the brake actuation shaft causes radial motion of both brake shoes toward the brake surface.