Mechanical expansion shaft
Series 410 Multicore (pneumatically activated)


with continuous expansion and centering ledges

The multicore expansion shaft is suitable for safe take-up of many narrow individual cores without being confined to fixed subdivision patterns. At the same time it achieves maximum possible moments of inertia, thus minimised bending values.

The centering ledges expand purely mechanically to centre and round the cores optimally on the expansion shaft. Even with increased loads the ledges remain "fixed" in position by virtue of the self-blocking mechanics, thus ensuring steady running and good reel build-up.

The expansion ledges expand purely pneumatically and thus ensure dependable torque transmission to every core. Expansion shafts with expansion ledges are available for cores with an internal diameter in the range from 150 to 600 mm.

By feeding compressed air into the pneumatic chamber the pneumatic piston is moved axially in the cylinder and displaces the internal cone driving rod. The uniform centering ledge expansion resulting therefrom ensures concentric clamping of the cores. When compressed air is fed into the cylinder chamber, the expansion ledges on the circumference of the shaft expand.

The expansion takes place with time delay produced by the flat bladders under the expansion ledges. These flat bladders ensure uniform torque transmission into every core, however narrow it may be.

After termination of the working procedure, the expansion and centering ledges are retracted to their initial position either by internal springs or by pressure application to the piston back side, so that the shaft can be taken out of the core.

Features and advantages

  • Concentric clamping of even
    the narrowest cores by proven mechanical
    Vorwald expansion system, thus ensures
    steady running of the reels, even with
    heavy reels and high web speeds
  • Transmission of highest torques
    by pneumatic expansion ledges
  • Special dimensions possible on inquiry
  • Simple pneumatic actuation of the
    expansion mechanism

  • Quick expansion and release, because
    only small amounts of air are required
  • High true running accuracy
  • Minimised bending by
    maximised moments of inertia
  • Very little maintenance required

    Available shaft diameters
    in the range from 148 to 600 mm