Patent ID: 8746815

Claim:
In vehicle track-module apparatus including an upper drive wheel connectable with respect to a vehicle axle for rotation therewith, a plurality of idler and bogey wheels, and an endless flexible rubber track with a main inner surface and spaced lugs projecting therefrom, the track extending around the wheels and driven by its engagement with the drive wheel, the improvement wherein the drive wheel comprises: a circular middle main plate having a central portion adapted for connection with respect to the vehicle axle, the plate terminating circumferentially in an edge of first diameter and having inward and outward sides forming inward and outward surfaces of the drive wheel; circumferentially-spaced drive members extending axially across and projecting radially beyond the main-plate edge to a second diameter, each drive member having an axially inward end portion, an axially outward end portion, a middle portion therebetween having a middle position, and an outer track-engaging surface, each drive member being affixed with respect to the main-plate edge with the main plate and the middle position substantially aligned; and a substantially flat rigidity ring concentric with the middle main plate and affixed to the drive members at the inward end portions thereof, the ring having an inner diameter no less than about half the first diameter and an outer diameter no greater than about the second diameter.