A clamping claw is disclosed. The clamping claw includes a base body with a support surface that rests on a slide rail and a clamp assembly. The clamp assembly includes a shaft mounted rotatably about a first rotational axis and a support element pivotably mounted about a second rotational axis. The clamping claw includes an activating member connected to the clamp assembly and configured to place the clamp assembly into a locked state in which the support surface and the support element both rest on the slide rail. The support element is moveable between a starting position and support position via the activating member. When the support element is in the support position, the clamp assembly is in the locked state. The clamping claw includes a locking mechanism to prevent movement of the activating member if the support element is in an intermediate position between the starting and support positions.