Ing C. Olivetti C., S.p.a.

Aldo Chiaro

Alessandro Scardovi

Andrea Accattino

Adriano Fetta

Each print element is connected to the head by means of a resilient blade pivoted on the head and is movable in two directions, respectively parallel and perpendicular to the direction of movement of the head, to vary the relative position of the nozzles. The nozzles of the print elements are disposed along a straight line which is inclined with respect to the direction of movement of the head. The head can be rotated to vary the inclination of the nozzles, thereby to provide different print definitions. A parking station is further provided for the head to clean and keep the nozzles in contact with an atmosphere saturated with a solvent for the ink, to prevent the ink from drying out in the nozzles.

Multiple nozzle ink jet dot printer

The apparatus is of the type wherein a piezoelectric transducer (19) is selectively operated to produce a pressure wave in the ink in a duct (16, 22), which causes a droplet of ink to be expelled from the nozzle (18). In order to absorb the energy of the pressure wave which is directed towards the ink reservoir (47) the duct comprises a portion (22) of viscoelastic material, which is so dimensioned as to damp the resonance of the duct for frequencies higher than a predetermined cut-off frequency. Frequencies which are lower than the cut-off frequency however are damped by an hour-glass shaped constriction (34) in a tube (33) disposed between the viscoelastic portion (22) of the duct and the reservoir (47). The second portion (22) of the duct comprises a polyamide base material, the modulus of elasticity of which is substantially stable over a wide range of possible operating temperatures. The second portion of the duct may comprise a flexible tube (22) or a double spiral passage (not shown) provided between two substantially square plates.

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Caluso, Italy

Aldo Chiaro