Star wheel with adjustable directional biaser

摘要

A print media feed system in a inkjet printer, the system has a media feed roll, a star wheel mounted opposing the roll, an adjustable biaser coupled to the star wheel, and a controller coupled to the biaser. The controller varies a magnitude, a direction or a magnitude and direction of a biasing force applied to the star wheel by the biaser. In one form, the biaser comprises a motor driven cam that varies the angular position of a pivotable lever having a star wheel rotatably attached on one end. In another form, a rack and pinion gear assembly is used to vary the biasing force with a star wheel rotatably attached to the rack. In a further form, a solenoid is used to vary the basing force applied to the lever or applied to a star wheel rotatably attached to the end of the shaft of a solenoid.

主权项

1. A print media feed system in an inkjet printer, said system comprising:
a feed roll; a first adjustable biaser comprising:
a first star wheel mounted opposing the feed roll forming a nip therebetween for receiving a sheet of media;a first lever having a first end pivotally mounted in the inkjet printer and a second end rotatably coupled to the first star wheel;a first motor;a first cam having an elliptical shape having a major axis, the first cam operably coupleable to the first motor at an off-center position on the major axis of the first cam; anda first biasing member holding the first lever against the first cam; and, a controller communicatively coupled to the first motor, the controller being configured to adjust the angular position of the first motor to adjust the angular position of the first cam, wherein, with the first cam having an angular position where the major axis is substantially parallel to the first lever, a biasing force on the first star wheel is directed away from the feed roll separating the first star wheel and the feed roll, and as the angular position of first cam changes during rotation and the major axis of the first cam changes away from being substantially parallel to the first lever, and first star wheel moves into contact with the feed roll and the sheet of media with first lever member being in an unflexed position with the biasing force on the first star wheel being directed toward the feed roll and sheet of media and increasing to a substantially maximum biasing force being directed toward the feed roll and the sheet of media when the major axis of the cam is perpendicular to the lever arm.