Resumen

Where it faces the linear drive (3,4,13) the coupling plate (6) carries a cylindrical sealing sleeve (needle projection 9a) which in turn encloses the needle-side end part (3) of the drive in close radial play, preferably 0.1-0.2 mm only. Axial overlap between sleeve and drive end part (3) lies between 3 and 10 mm. The exterior of the sleeve (9) and ring wall of the sleeve are fitted with grips (11) and the drive end (3) consists of a guide sleeve in which the drive part (2) runs.