Patent ID: 8517522

Claim:
An apparatus for use in fluid jetting, the apparatus comprising: a printhead including a flow path and a nozzle in communication with the flow path, the flow path having a first end and a second end; a first container fluidically coupled to the first end of the flow path, the first container having a first controllable internal pressure; a second container fluidically coupled to the second end of the flow path, the second container having a second controllable internal pressure; and a controller to control the first internal pressure and the second internal pressure to have a fluid flow between the first container and the second container through the flow path in the printhead according to a first mode and a second mode, while in either mode, at least a portion of the fluid flowing along the flow path is delivered to the nozzle when the nozzle is jetting, the first mode having the first internal pressure higher than the second internal pressure and the second mode having the second internal pressure higher than the first internal pressure, the fluid flowing from the first container to the second container according to the first mode and flowing from the second container to the first container according to the second mode.