Closure apparatus incorporating a magnetic clutch for screwing-on a plastic screw closure - Patent US4364218(A)

Filed: Apr 25, 1980

Published: Dec 21, 1982

Abstract

A magnetic clutch is provided for transmitting and limiting the torque in screw-on heads for screw closures. The clutch has a high number of poles (at least eight and preferably twelve poles) and the spacing between the clutch magnets, is at least six times the total axial tolerances between the clutch magnets.