In the coking process of coal by the coal compressing process, the coking coal is compressed by power hammers before it is introduced into the coking furnace. Elongate rods (2, 3) comprising power hammers (1) are lifted above the coking coal by means of driven disks (5, 6) which operate by sectors, and are then released. The shafts (7, 9) supporting the disks are mounted individually with respect to the number of hammer rods. The bearing points (22) may be moved simultaneously and in the same direction on either side of the rods of the power hammers and are uniformly driven by a hydraulic system. Consequently, the independent shafts of the disks are set in motion and the disks are pressed against the rods of the corresponding power hammers. A regular and uniform lifting of all the power hammer rods and all the power hammers is obtained.