Patent ID: 7770810

Claim:
A track assembly comprising: first and second cylindrical rail tubes coupled to respective support members and a plurality of cross members interconnecting the support members; each support member including a hollow part and two flanges; the hollow part including a first side formed to match the curvature of a selected outer circumference of a rail tube; the first side of the hollow part supporting the rail tube; the hollow part including a second side, the flanges extending from the second side with a gap therebetween; the hollow part including a third side for supporting the track; a cross member having first and second opposed ends; the first cross member end having an uncurved corner substantially opposite a curved corner; the second cross member end having an uncurved corner substantially opposite a curved corner; the uncurved corner of the first cross member end located diagonally with respect to the uncurved corner of the second cross member end; the curved corner of the first cross member end located diagonally with respect to the curved corner of the second cross member end; the first cross member end inserted in the gap of the first support member and rotatably coupled to the flanges forming the gap; the second cross member end inserted in the gap of the second support member and rotatably coupled to the flanges forming the gap; the track having collapsed and extended states; in the extended state, the cross members extend between the support members with only the cross member ends located in the respective gaps; and, in the extended state, each uncurved corner limits rotation of the cross member with respect to a support member in one direction.