Ink drop generator for ink jet printer

An ink jet printing machine comprising at least one ink drop generator, means for connecting said generator to a source of ink, said drop generator comprising a mechanical vibrations amplifier having two ends, one end of which is adapted to be vibrated and the other end adapted to have ink emitted therefrom, said amplifier including a passage extending between its two ends, and further including an ink supply tube connected to the said passage on the side of said one end of the amplifier, an electromechanical converter device connected at said one end of said amplifier for vibrating said one end to cause ink emitted from the other end to break up into drops at a point close to said other end, means for electrically exciting said converter device to impart a vibratory movement to said amplifier, a compensating block attached to the said converter device and arranged so as to set up in the said converter device a nodal vibration zone, said compensating block including an aperture for the passage of said ink supply tube, said tube having parts situated outside said nodal zone, the transverse dimensions of said aperture being greater than those of the tube such that the compensating block is maintained out of contact with said those parts of the tube situated outside said nodal zone, and attachment means for holding the drop generator in position in the ink jet printer, said attachment means including a first attachment member having a part in contact with said generator, said part being situated in said nodal vibration zone.

A drop generator for use in ink jet printers, comprising a support member made of a thin metallic plate, a pair of electromechanical converter elements mounted one on each side of said plate, a mechanical vibration amplifier having two opposite ends of which one of said opposite ends is mounted on one of said converter elements, said amplifier including a passage extending between its two opposite ends and forming at the other end of said amplifier at least one opening adapted to have ink emitted therefrom, an ink supply tube passing through an aperture in said metallic plate and said converter elements and connected to the said passage on the side of said one end of the amplifier, means for electrically exciting said converter elements to impart a vibratory movement to said amplifier and to cause ink emitted from said opening to break up into drops at a point close to said opening, and a compensating block mounted on the other of said converter elements and arranged so as to set up in said metallic plate a nodal vibration zone, said compensating block including an aperture for the passage of said ink supply tube, said tube having parts situated outside said nodal zone, the transverse dimensions of the aperture of said block being greater than those of the tube such that the compensating block is maintained out of contact with those parts of the tube situated outside said nodal zone.