A gripper device for holding a flexible flat sheet around an elongated form such as a cord, rope, protruding edge or the like. The device is formed in the preferred embodiment with an inner hinged gripper which is positioned around the elongated form such as a protruding edge on a bed mattress. An outer clamp is formed in a C-shaped configuration and slides over the inner hinged gripper. To apply a force or pressure on the gripper, a tapered surface is formed on the outer side of the inner gripper and on the inner side of the outer C-shaped clamp.
