Coupling device for a load bearing device

The device (2) has a clamping bracket (21) pivoted and clamped around a pivot axis by pivoting movement of a lever (10), where the lever is used as a control element. The pivoting movement of the lever is converted into pivoting movement of the clamping bracket up to a locating point via a four-joint while converting the pivoting movement of the lever into the clamping movement of the clamping bracket. A transmission element (36) is arranged eccentrically with respect to the pivot axis of the lever.