Abstract: The invention concerns a clamping device for a nonskid tire chain with a housing and an actuation member, which has a lock-in position, in which a clamping cord which can be pulled into the housing through an opening in the housing, can be blocked counter to its clamping direction, as well as a release position, in which the blocking is canceled, and the clamping cord within the housing is connected to a winding roller preclamped in the winding-up direction, which [roller] is mounted so that it can rotate around its axis, whereby a ratchet wheel at the winding roller is provided with at least one spring-loaded safety catch assigned to it, and a second ratchet wheel is provided with a spring-loaded safety catch assigned to it, and the two ratchet wheels are joined with one another in a way that resists rotation, whereby the blocking directions of the ratchet wheels are opposite directions, and the spring-loaded safety catches of the first or the second ratchet wheel can be engaged reciprocally with t