Pneumatic expansion coupling
Series SPM/SPZ (pneumatically activated)

with continuous expansion leafs made of aluminium

The Vorwald expansion couplings of the Series SPM/SPZ are based on the principle of the expansion shafts of the Series L. In contrast to conventional expansion couplings which clamp an inflatable expansion ring directly against the core, this type of coupling uses lengthwise grooved expansion leafs made of aluminium. The expansion leafs are expanded by an internally seated replaceable bladder. This arrangement avoids the damage and wear to the bladder which is experienced in other designs. The aluminium expansion leafs are also equipped with an expansion stop, so that this expansion coupling may be clamped with a pressure of up to 6 bar even without winding core, since the stop prevents the bladder bursting. The large contact area of the expansion leafs on the bladder produces a clamping force when activated with compressed air that holds the core securely in place, even in the case of quick starting and stopping.

Various take up diameters are available depending on the external diameter. A version with flange or bearing journal, the Series SPZ, is also possible.

The chief application field of this expansion coupling is for thin walled cores that are easily deformed and can become unusable with other expansion elements.


  • Surface protection is possible
  • Version suitable for
    the foodstuffs industry
  • Free positioning of a core stop
  • Flange version
  • Special dimensions
    are available on inquiry


  • Very quick conversion to other core diameters
  • Small weight of the coupling
  • Simple handling
  • Eminently suitable for narrow webs and
    thin walled cores
  • Conceived for "light" applications
  • Take-up bore according to customer specifications

    The standard sizes are
    70, 76, 150 and 152 mm