Patent ID: 6568802
Filing Date: 2003-05-27
Classification: B41J

Abstract:
An ink feeding circuit device for a raster drawing machine comprising an ink jet printing head (1) supported by a head bridge bar (22) traveling on guides of the drawing machine (10), the ink jet printing head (1) moveable in an x and y direction over a drawing plane (20) of the drawing machine, drawing paper (14) supportable on the drawing plane, a feed circuit having a stationary ink supply reservoir (2) connected with the movable ink jet printing head (1) by a conduit (31), and, a gas damper (9) which is in fluid communication with the conduit, the gas damper being a gas filled pipe, the gas remaining in the pipe, the pipe oriented in a vertical direction (25) above the conduit, and above the ink therein, and being located near the ink jet printing head, and movable therewith, a meniscus being formable between the ink in the conduit and the gas in the damper, to form a seal therebetween, the printing head located above an ink level (5) inside the supply reservoir (2) such that the printing head is operated under negative pressure.