FLUID DISTRIBUTION SYSTEM HAVING MULTI-CHANNEL FOUR-WAY VALVE
A fluid distribution system for a printhead, the system having a plurality of fluid containers fluidically interconnected with the printhead via a respective plurality of closed fluid flow loops, a plurality of bypass fluid paths bypassing the printhead, each bypass path being associated with a respective one of the closed loops and a plurality of gas vents, each gas vent being associated with a respective one of the closed loops and a multi-channel four-way valve for selectively allowing fluid flow along each closed loop via the printhead and the bypass paths and venting of gas in each closed loop via the gas vents.
1 . A fluid distribution system for a printhead, the system comprising:
a plurality of fluid containers fluidically interconnected with the printhead via a respective plurality of closed fluid flow loops;
a plurality of bypass fluid paths bypassing the printhead, each bypass path being associated with a respective one of the closed loops; and
a plurality of gas vents, each gas vent being associated with a respective one of the closed loops; and
a multi-channel four-way valve for selectively allowing fluid flow along each closed loop via the printhead and the bypass paths and venting of gas in each closed loop via the gas vents.
2 . A system according to claim 1 , wherein the printhead is an elongate printhead spanning a media width, each closed loop comprising a first path between the respective container and a first longitudinal end of the printhead and a second path between the respective container and a second longitudinal end of the printhead.
3 . A system according to claim 2 , wherein each bypass path bridges across the printhead between the respective first and second paths.
4 . A system according to claim 2 , wherein the gas vents are located on the respective first paths.
5 . A system according to claim 2 , wherein the valve is located on the first path.
6 . A system according to claim 2 , wherein each gas vent comprises a filter disposed at one end of a vent line, the opposed end of the vent line joining the respective first path.
7 . A system according to claim 6 , wherein the filters comprise expanded polytetrafluoroethylene
8 . A system according to claim 6 , wherein each closed loop, bypass path and vent line comprise fluid hoses.
9 . A valve according to claim 1 , wherein five fluid flow loops are provided between five fluid containers and the printhead.