Noise Reducing Technologies for Newly Designed Percussion Drills.
Paper in Noise-con '88 Purdue Univ 1988 :123-128
The culmination of a long-term Bureau of Mines research effort into hand-held pneumatic percussion drill noise controls has resulted in the commercial availability of a reduced-noise hand-held pneumatic drill that is as quiet as similar classes of hydraulic drills. This technology can also be used to redesign other classes of pneumatic percussion drills and should result in similar noise reductions of up to 15 dba. It is important to note that this reduced-noise drill has similar drilling rates to existing drills. Also similar classes of hand-held percussion drills weigh about 50 pct more than this new design, which has a fiberglass feedleg. This weight reduction has the potential to greatly increase production owing to reduced times to set the drill up to drill each hole. At the same time the reduced weight has the potential to reduce the incidence of back injuries.
Paper in Noise-con '88, Purdue Univ., 1988, PP. 123-128