guided by the stop pins 46 of the first stop element 44 the stop pins 46 are further embodied and disposed for the contact pressure piston 33 by the grooves 39 of the first stop section 38 to be able to encompass the stop pins 46 so that the contact pressure piston 33 is movable into a first annular space 47 between the take up section 24 and the stop pins 46 a detailed description of the stop pins 46 and the arrangement thereof will follow taken in conjunction with the description of the second stop element 45 the second stop element 45 also comprises several stop pins 46 which form one piece with the collar 29 of the cap 28 and extend along the central longitudinal axis 14 a two piece design possibly of various materials is also conceivable the stop pins 46 are disposed in a circle around the central longitudinal axis 14 forming a flush prolongation of the cap aperture 31 so that the tappet 15 is additionally guided by the stop pins 46 to this end the stop pins 46 are embodied as ring segments with a guide wall 48 that is turned towards the tappet 15 being arched corresponding to the periphery of the tappet 15 proceeding from the cap collar 29 each stop pin 46 tapers towards the frictional damping lining 36 having two side walls 49 and a front wall 50 on its side turned away from the tappet 15 each stop pin 46 additionally comprises an outside wall 51 which extends in the form of a ramp in the direction of the cap.