Abstract: A clamp has a first curved portion with one end connected to a second curved portion which overlaps or surrounds a segment of the first curved portion including the free end thereof. The free end of the second curved portion is connected to an extension, which has an elongated slot adjacent its end and an inclined lower surface adjacent its end. A base extends from one of the first and second curved portions in substantially the same direction as the extension and has an inclined upper surface at its end for cooperation with the inclined lower surface of the extension. The base has an opening extending therethrough to receive a screw, which passes through the slot in the extension prior to passing through the opening in the base.