Abstract: An apparatus for the releasable, force-locking connection of two telescopically arranged tubes, especially for clamping the steering housing tube in the steering fork tube of a bicycle or the like, comprising an expanding cone axially displaceable within the tube defining an inner tube by means of a threaded spindle. In order to avoid, during clamping, deformation of the inner tube and thus frictional connection between both tubes along only a circular engagement line at the lower end of the inner tube and to eliminate the effect of the unavoidable play between the outer diameter of the inner tube and the inner diameter of the outer tube, the outer surface of the expanding cone bears against wedges. The latter are each arranged in a respective guide slot formed at the inner tube, extending parallel to the lengthwise axis of the tubes and having a closed contour.

Abstract: An apparatus for the treatment of workpiece surfaces which comprises means for elevating the particles to a path of free fall for such particles without entraining the workpieces, means for supporting and rotating the workpieces at the region of free fall of the particles, and means for introducing a friction-reducing medium for contact with the workpieces and particles.