| 摘要 |
<p>A screwcapping head (10) for applying prethreaded closures onto prethreaded containers having a hysteresis clutch (44). The screwcapping head (10) includes a housing (16) adapted to be secured to a rotatable drive spindle (12) and a quill (36) mounted in the housing for free rotation therewith. The screwcapping head (10) also includes a hysteresis clutch (44) having a pair of permanent magnetic rings (46, 48) secured to the housing (16) and a disc of hysteresis magnetic material (50) secured to the quill (36) and sandwiched between the pair of permanent magnetic rings. The clutch (44) is capable of slipping after the application of a prethreaded closure onto a prethreaded container at a desired torque value while eliminating the torque reversal feature inherent in synchronous clutches.</p> |
