DISPOSITIVO DI AZIONAMENTO DELL'ASTA PORTA-AGO IN MACCHINE PER CUCIRE CON COMPENSAZIONE DELLE MASSE

摘要

The needle bar drive of a counterbalanced sewing machine comprises, in addition to a counterbalance weight connected to the driving crank, a second counterbalance weight which is driven in opposition thereto through a drive mechanism. The drive mechanism comprises an intermediate shaft which rotates at a double speed relative to the armshaft and carries and drives a third counterbalance weight.