Carriage stabilization during periodic valve engagement for printhead

Abstract

An ink-jet printing system includes a printer frame structure, with a carriage mounted on the printer frame structure for movement across a print zone during normal printing operations and which is positionable in a refill position. At least one printhead is mounted on the carriage, with an inlet port accessible without having to remove the printhead. A support bracket is attached to the printer frame structure. The system further includes at least one ink supply valve mounted on the support bracket. A clamp structure is mounted on the support bracket and moveable between a clamping position for engaging the carriage in the refill position and stabilizing its position during a refill operation, and a disengaged position wherein the clamp structure is not in contact with the carriage. An automated mechanism is operatively connected to the support bracket which moves the clamp structure from the disengaged position to the clamping position, and which moves the at least one ink supply valve toward the carriage in said refill position for engagement of the ink supply valve with the inlet port of the printhead mounted in the carriage. The clamp structure is adapted to exert reaction clamping forces on said carriage in response to pen engagement forces exerted on the carriage during the pen engagement so that the resultant reaction on the carriage as a result of the clamping forces and the pen engagement forces is virtually nulled.