Patent ID: 8231385
Filing Date: 2012-07-31
Classification: A61C

Abstract:
1. A dental handpiece comprising: a burr sleeve for receiving a dental treatment tool therein, a head section housing rotatably supporting said burr sleeve therein, an air supply passage for introducing compressed air into the head section housing for rotatably driving the burr sleeve with the compressed air, and an air discharge passage for discharging the compressed air, wherein said air supply passage comprises: a through hole axially extending through a rear terminal part of the dental handpiece, and a tubular pressure regulating member and an air supply tube connected in series between a distal end of the through hole and the head section housing, said tubular pressure regulating member further comprising: a first tubular member, a second tubular member inserted in said first tubular member to form a gap therebetween, an aperture provided in each of said first and second tubular members at a predetermined position for allowing communication between an interior of the tubular pressure regulating member and the air discharge passage, an annular valve body arranged axially slidably for selectively allowing and preventing communication between said apertures, and a spring for biasing said annular valve body, wherein the aperture in the second tubular member is axially displaced from the aperture in the first tubular member, wherein the annular valve body and the spring are arranged in the gap between said first and second tubular members, wherein the annular valve body fits between said first and second tubular members slidably and contacts both said first and second tubular members, wherein said annular valve body is biased by the spring into a position to prevent communication between the apertures in the first and second tubular members, and is arranged to receive pressure from the compressed air passing through the air supply passage, wherein, when a pressure of compressed air passing through the air supply passage exceeds a predetermined level, said annular valve body is slid by the pressure against the force of the spring to provide communication between the apertures, whereby the compressed air is discharged through the apertures into the air discharge passage for regulating the pressure of the compressed air to be supplied to the burr sleeve.