Patent attributes
A clamp structure for a tonneau cover is disclosed and mounted to one frame section of a tonneau cover for releasably securing the frame section on a cargo bed of a pick-up truck. The clamp comprises: a foundation rail having two side grooves and a recess formed between the two side grooves; and a sliding block having two side hangers extended into and slidably moving along the two side grooves and a pivotal portion received in the recess; a clamp bolt; a grip element; and a handle. The side hangers of the sliding block is used to slidably move along the side grooves of the foundation rail, so that the sliding movement of the clamp structure pivotally connected to the sliding block in relation to the foundation rail is more stable and smooth based on two strong support points of the two side hangers in the two side grooves.