| 摘要 |
An ultrasonic ink seal for use in a printing press having a metering roller (20) having an outer surface (40) and at least first and second devices (60, 62) for applying first and second inks, respectively, to the outer surface (40) of the metering roller (20). The ultrasonic ink seal has a plurality of piezoelectric transducers (91, 92, 93) and a deflecting device (96, 100, 102) for deflecting the ultrasonic sound waves produced by the piezoelectric transducers (91, 92, 93) toward a predetermined area (70) on the surface (40) of the metering roller (20). The ultrasonic sound waves cause the first and second inks to be forced away from the predetermined area (70) thereby providing a separation of the first and second inks. In a preferred embodiment the deflecting device (96, 100, 102) has a horn (96) having a curvature approximately equal to a curvature of the outer surface (40), of the metering roller (20), the horn (96) having at least first and second deflecting surfaces (97, 98). The deflecting device (96, 100, 102) also has first and second reflectors (100, 102) having first and second reflecting surfaces (104, 106), respectively, the first and second reflecting surfaces (104, 106) orientated toward the first and second deflecting surfaces (97,98) such that the ultrasonic sound waves that are deflected from the first and second deflecting surfaces (97, 98) are focused onto the predetermined area (70) of the surface (40) of the metering roller (20).
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