PRINT HEAD AND PLASTIC BEARINGS THEREFOR

摘要

IMPROVED PRINT HEAD AND PLASTIC BEARINGS THEREFOR A print head for impact printers of the dot matrix type comprising a hollow die cast housing having solenoids mounted upon a rear wall thereof and having print wires driven thereby and extending through the rear wall and hollow housing toward the forward end. A plastic bearing is releasably mounted in the forward wall and serves as a low friction bearing for the reciprocating print wires and to prevent abrasive wear of the print wires when in the retracted position. The guide plates mounted within the housing and intermediate the forward and rearward ends thereof support curved guide tubes for maintaining relative positioning of the print wires as well as maintaining their desired natural curvature. The plastic bearing is formed of a plastic material for significantly increasing operating life and which is compliant to attenuate a significant amount of side loading due to impact. The plastic materials used to form the bearings are admixed with additives to make the bearings self lubricating. The plastic bearings are arranged to be readily removed and replaced.