Title:
PRESET ROTATION SPEED MAINTENANCE DEVICE FOR DENTAL HANDPIECE
Document Type and Number:
Japanese Patent JP2769798
Kind Code:
B2
Abstract:
PURPOSE: To easily and properly maintain the number of revolutions of a drive mechanism at a preset value, regardless of a no-load or a loaded condition, and improve cutting efficiency by providing a rotation speed detection means for detecting the number of revolutions of the drive mechanism and a rotation speed adjusting means for correcting a difference between the detected number of revolutions and the preset number of revolutions.
CONSTITUTION: A microphone 11 is provided within a joint 21 of an exhaust pipe 22b where compressed air flows, and a sound pressure of a noise generated due to rotating motion of an air turbine is converted to an electrical signal, wherever necessary. An amplifier 12 and an electrical filter 13 shape the electrical signal and a frequency thereof is converted to voltage via an FV converter 14, thereby providing converted voltage as an index to show a speed of the air turbine. Also, a comparator 15 makes a comparison between the converted voltage and reference voltage corresponding to the preset number of revolutions, and a resultant difference is amplified with an amplifier 16. Furthermore, a compressed air supply source 22 is provided with a control valve 17 for correcting the difference on the basis of an amplified value, thereby adjusting feed volume of the compressed air.
Inventors:
Hiroshi Horiuchi
Kawata Shosaku
Kawata Shosaku
Application Number:
JP15031595A
Publication Date:
June 25, 1998
Filing Date:
June 16, 1995
Export Citation:
Assignee:
NAKANISHI INC.
International Classes:
A61C1/02; A61C1/05; A61C1/08; (IPC1-7): A61C1/02; A61C1/05; A61C1/08
Domestic Patent References:
| JP5427294A | ||||
| JP5444386A | ||||
| JP63143054A | ||||
| JP370553A | ||||
| JP60149620U |
Attorney, Agent or Firm:
Sakai Hajime