Acoustic Resonator Arrangement
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
An air resonator arrangement is provided for reducing low frequency noise, pure tones and, also, for eliminating acoustic beats of two air-moving devices operating together to cool an enclosure for an impact printer. (Image Omitted) As shown in the schematic of Fig. 1, blower unit 10 is used for vacuum removal of ribbon debris from the face of a type band of printer mechanism. The blower unit 11 is used to draw cooling air through the carriage motors which advance print form paper. Both blower units are 3-stage vacuum/compressor blowers that exhaust filtered air through muffler unit 12. The blowers generate considerable noise at the exhaust ports. The noise emission is primarily of low frequency, ranging from 125 to 1000 Hz.