sliders for a construction with few slides also there is a rod 16 fig3 4 in the piezoelectric extender section it extends from the rear end of the piezoelectric extender section 4 fig1 to its front end the transverse bar of the u shaped bracket 6 fig4 of the rear piezoelectric clamp section 3 and the rod 16 are connected with a threaded connection the transverse bar of the u shaped bracket 9 fig1 of the front piezoelectric clamp section 5 and the rod 16 are connected with a threaded connection direction of the piezo stack 14 and 15 length variation at coming an electric voltage to them coincides with the direction of the rod 16 there is a foramen 17 inside the piezoelectric extender section 4 fig3 4 that connects the internal space of the housing near the rear end of the piezoelectric extender section with an internal space of the housing near the front end of the piezoelectric extender section intended for additional cooling of the piezo stacks 14 and 15 as well as for possible flow of liquid through the piezoelectric extender section 4 fig3 4 there is a clearance between the piezoelectric extender section 4 and the rod 16 disposed inside it the foramen 17 is formed by a clearance between the rod 16 and the piezoelectric extender section 4 in the piezoelectric extender section 4 near its rear end there is a hole 18 connecting the foramen 17 with the internal space of the housing also in the rear piezoelectric clamp section 3 in the bracket 6.