Mechanism for improving tufting machine needle bar shifting

摘要

A tufting machine has a transversely shiftable needle bar driven by a pattern cam, the needle bar is further acted upon by biasing mechanism arranged to urge it in a direction opposite to the direction it is being driven by the cam so as to take up the lost motion due to clearances in the cam drive system. The specific biasing mechanism disclosed is an air thruster acting on a pivotably mounted bracket having a roller acting on the needle bar in opposition to the load applied by the cam. The load is applied by a pivotably mounted arm connected to the cam drive. The arm is also connected by a rod to the bracket as an assurance.