| 摘要 |
An improved wheel assembly is provided for use with a shopping cart or the like to restrain the cart against rolling movement when parked. The improved wheel assembly comprises a wheel rotatably supported on the cart or the like by a friction bearing unit which imparts a predetermined frictional resistance to rolling movement of the wheel. The magnitude of the frictional resistance is chosen to prevent the cart from rolling about when parked, for example, on a gentle slope while permitting the cart to be pushed about in a normal manner.
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