Electrohydraulic needle bar positioning apparatus for tufting machines

摘要

A hydraulic actuator for transversely shifting the relative positions of a needle bar and the backing material in a tufting machine. An electronic pattern control mechanism drives the hydraulic actuator in response to the predetermined stitch pattern information in the electronic control circuit, which determines the amount of relative transverse shifting of the needle bar for each stitch location. A feedback mechanism associated with the hydraulic actuator creates a feedback signal which is compared with a pattern stitch command signal in order to produce an output signal for shifting the hydraulic actuator to a subsequent transverse needle bar position relative to the preceding needle bar position.