Tension device for a slide protection chain

The clamping device has housing, a winding wheel (3) and a pawl (6), arrange in a winding wheel. The winding wheel is rotatably supported within the housing around its axis and is boased in the winding direction. The winding wheel has a ring gear (31) with a toothing (33) arranged along its periphery. An area is formed on a circumference of the ring gear of the winding wheel, which is free from toothing and is located between adjoining teeth. An independent claim is also included for an anti-skid chain with holding elements, particularly hooks.