Abstract: The invention relates to a clamp apparatus for application to an object, for example a plate, a sheet, a fabric or a thin film, by gripping two opposite sides of the object. For this purpose, the apparatus comprises a tubular element with an inner passage with a cross section which tapers in the direction of one end of the element and a clamp surface projecting from the opposite end of the element. A wedge shaped element with a tapering section is insertable into the passage via its wide opening. Thereby, a nip is formed in the co-operation between the wedge shaped element and the clamp surface.