Patent ID: 8092001

Claim:
A liquid jetting apparatus which jets a liquid, comprising: a head which jets the liquid; a liquid storage chamber which communicates with the head, and in which the liquid to be supplied to the head is stored; a gas distributing chamber communicating with the liquid storage chamber, and having a gas introducing hole in which a gas, to be fed to the liquid storage chamber, is formed; a first valve which opens and closes the gas introducing hole; a gas introducing mechanism which introduces the gas through the gas introducing hole to feed the liquid in the liquid storage chamber to the head so that the liquid is forcibly jetted from the head; a buffer chamber having a communicating hole and an atmosphere opening hole formed therein, the communicating hole communicating with the gas distributing chamber, and the atmosphere opening hole introducing an atmosphere; a positive-pressure control valve which opens the atmosphere opening hole when a positive pressure inside the buffer chamber exceeds a predetermined value; and a second valve which opens and closes the communicating hole; wherein the first valve and the second valve are formed integrally; wherein an air layer is formed in the liquid storage chamber, and the gas introducing hole communicates with the air layer; wherein the gas introducing hole is formed to face the communicating hole; wherein the liquid jetting apparatus further comprises a bias applying mechanism which applies a bias in a direction in which the first valve is separated away from the communicating hole to close the gas introducing hole; and wherein, when the first valve opens the gas introducing hole against the bias applied by the bias applying mechanism, the second valve closes the communicating hole.