Abstract: Disintegrated material is supplied to a pressure chamber by a rotatable and axially translatable screw piston. The piston is rotated while in a first axial position to transport and compact the material in a receiving chamber against a closed output valve in front of the piston. The output valve is opened and the compacted material is moved into the pressure chamber by axial non-rotative motion of the piston. The output valve then is closed, and the piston is axially returned to its first axial position while rotating in the same direction as before. The operation cycle is repeated as above. An apparatus for carrying out a process comprises an axially movable guide piston rotationally carrying and guiding the screw piston for rotation and axial movement by action of a hydraulic cylinder and a mechanism for rotationally positioning the screw piston.

Abstract: An annular piston has a bore threaded to a bolt end and is disposed between a base and a nut in axially spaced relation to the nut, there being an annular cylinder slidably receiving and surrounding the piston and defining an annular pressure chamber therewith, the cylinder being disposed between the base and the nut so that the nut can be tightened to act axially through the cylinder against the base in the absence of any pressure in the chamber. With pressure present in the chamber of a magnitude which tensions the bolt, after pre-tension has been overcome, the nut is free to be rotated to a desired setting.