A basic body (1) is built as a hollow profile (8) and a second wedge surface (5) is provided to clamp around a second section (6) of the rail foot, lying opposite a first section (4) clamped by a first wedge surface (3). The second wedge surface is connected to an insert profile (7) which is guided and moveable located inside the hollow profile. The second wedge surface is also movable under overriding of a spring force from a position near to the rail foot to a position where at least the second section of the rail foot is free. The base body consists of a square end hollow profile and the first wedge surface consists of a U-form clamping piece (9) connected to the base profile. The web (10) of the clamping piece has a wedge-form recess (11) appropriate to the rail foot section.
