a caster wherein the wheel can be braked by a reciprocable or pivotable brake shoe and the wheel frame can be held against swiveling relative to its carrier by an integral part of the carrier in cooperation with a reciprocable or pivotable component which shares the swiveling movements of the wheel frame and can directly or indirectly engage the internal teeth of such integral part . the integral part of the carrier and the reciprocable or pivotable component are installed in a chamber which is defined by the carrier and the wheel frame . the reciprocable or pivotable component is connected to the wheel frame in a plane which is different from the plane of the integral part of the carrier so that the forces which develop when the device including the integral component of the frame and the reciprocable or pivotable component is called upon to hold the wheel frame against swiveling movement are not concentrated in a single portion of such device . this allows for the making of the constituents of such blocking device from inexpensive synthetic plastic materials .