Patent ID: 7556468

Claim:
A wheel grid comprising: a cross bar; a first wheel retainer coupled to the cross bar, and comprising a first arm supported at the cross bar and configured to move between a stowed position and a use position, a second arm movably coupled to the first arm and configured to move between a stowed position and a use position, and a first cam configured to engage the cross bar as the first arm moves from the use position to the stowed position for moving the second arm from the use position to the stowed position; and a second wheel retainer coupled to the cross bar and comprising a third arm supported at the cross bar and configured to move between a stowed position and a use position, a fourth arm movably coupled to the third arm and configured to move between a stowed position and a use position, and a second cam configured to engage the cross bar as the third arm moves from the use position to the stowed position for moving the fourth arm from the use position to the stowed position.