| 摘要 |
A rolling support platform device is provided to assist in drawing, marking, writing, etc. The platform device also may be used as a teaching aid and by the handicapped, etc. The device includes a metal or plastic platform having three or more socket-shaped, partial knock-outs and a ball bearing in each socket. Sufficient friction is imparted to a bearing by each socket, thereby producing a smooth rolling action without the problems of over rolling.
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