The sealing member of a crown cork fitting machine includes a centring head and a sealing crown. In the centre of the housing is a stepped spring loaded cylindrical pressure element with magnets. Control of its travel is simplified by movement of the housing. The pressure element has parts of different diameters, the largest part sliding in spherical bearings, and a smaller part guided by a bush sliding in the sleeve carrying the ball bearings. The top part carries a bush forced against the sealing member cover. Between this bush and the lower bush is a spring.
