Abstract: The subject invention is a clamp that has two halves of an annular ring hingedly connected at one end and capable of being securely fastened to each other at the opposite end. The annular ring is sized to fit tightly around a vertical support post. An upper surface of the annular ring has an upper annular channel, while the lower surface of the annular ring has a lower annular channel. When the clamp is fixed to the vertical support post, a horizontal support adaptor may fit into both the upper and lower annular channels. A resilient engagement strip or button on the adaptor is placed into contact with the lower annular channel in this position and frictionally engages the lower annular channel to prevent lateral movement of the adaptor on the annular ring until such time as the adaptor may be securely attached to the annular ring.

Abstract: The subject invention is a clamp that has two halves of an annular ring hingedly connected at one end and capable of being securely fastened to each other at the opposite end. The annular ring is sized to fit tightly around a vertical support post. An upper surface of the annular ring has an upper annular channel, while the lower surface of the annular ring has a lower annular channel. When the clamp is fixed to the vertical support post, a horizontal support adaptor may fit into both the upper and lower annular channels. A resilient engagement strip or button on the adaptor is placed into contact with the lower annular channel in this position and frictionally engages the lower annular channel to prevent lateral movement of the adaptor on the annular ring until such time as the adaptor may be securely attached to the annular ring.