Reivindicaciones

1. Ink feeding circuit device for a raster drawing machine comprising an ink jet printing head (1) supported by a head bridge bar (22) travelling on guides of the drawing machine (10) and enabling the ink jet printing head (1) to move in x and y direction over the drawing plane (20) bearing the drawing paper (14) of the drawing machine (10) and comprising a feed circuit including an ink supply reservoir (2) connected with the ink jet printing head (1) by a conduit (31) which communicates with a gas damper (9). 2. Ink feeding circuit device in accordance with the first claim, characterized by the location of the gas damper (9) between the ink reservoir (2) and the printing head (1). 3. Ink feeding circuit device in accordance with claims 1 and 2, characterized in that the gas damper (9) comprises a gas filled pipe oriented in accordance with the vertical direction (25) above the level (30) of the conduit (31) enabling the gas to remain in the tube (21), because of its lower gas density and because of the resistance to change the state caused by the surface tension on the meniscus (19) of the ink facing the gas. 4. Ink feeding circuit device in accordance with claims 1 to 3, characterized by the location of the printing head (1) above the ink level (5) inside the supply reservoir (2) enabling the printing head (1) to work under some milibars of negative pressure.