Abstract: Provided with a weight release device capable of being operated in deep sea same as the conventional weight release device without accompanying a mechanical operation at all to avoid troubles of mechanical operation occurred in the conventional weight release device. The weight release device includes a housing fixed to the underwater observation device; a thread made of thermoplastic resin; electric heater portions; a weight support plate; a locking member of the thread made of the thermoplastic resin; and a ring for hanging the weight. The thread made of the thermoplastic resin is arranged from a start point housed in the housing, arranged to pass through the first electric heater portion, locked to the locking member of the thread made of the thermoplastic resin, arranged to pass through the second electric heater portion housed in the housing, and returned to an end point housed in the housing. The ring for hanging the weight is fixed to a lower surface of the weight support plate.

Abstract: Provided is a dental ultrasonic cleaning device that efficiently cleans teeth or dentures in an oral cavity using ultrasonic waves. A dental ultrasonic cleaning device 1 emits ultrasonic waves through a cleaning-liquid (W1) to the surface of a cleaning-target 26, ultrasonically cleaning it. An ultrasonic horn 24 propagates ultrasonic waves being generated by an ultrasonic-wave transducer 23 and emits them from the vibratory surface 25 provided at the tip-end of the horn 24. A liquid-reserving part 27 is provided, surrounding the vibratory surface 25 of the ultrasonic horn 24, which temporarily reserves the cleaning-liquid (W1) between the vibratory surface 25 and the cleaning-target 26. A cap-member 33 is provided at a certain interval opposite the liquid-reserving part 27.

Abstract: Provided is a dental ultrasonic cleaning device that efficiently cleans teeth or dentures in an oral cavity using ultrasonic waves. A dental ultrasonic cleaning device 1 emits ultrasonic waves through a cleaning-liquid (W1) to the surface of a cleaning-target 26, ultrasonically cleaning it. An ultrasonic born 24 propagates ultrasonic waves being generated by an ultrasonic-wave transducer 23 and emits them from the vibratory surface 25 provided at the tip-end of the horn 24. A liquid-reserving part 27 is provided, surrounding the vibratory surface 25 of the ultrasonic horn 24, which temporarily reserves the cleaning-liquid (W1) between the vibratory surface 25 and the cleaning-target 26. A cap-member 33 is provided at a certain interval opposite the liquid-reserving part 27.

Abstract: An ultrasonic motor having a stator in which at least a longitudinal vibration is generated and a rotor rotatably mounted on the stator. Slanted slits are formed on the cylindrical surface of the rotor, which convert a part of the longitudinal vibration in the stator into a twisting vibration that gives the rotor a rotational force. The slits are slanted to the rotational direction of the rotor. The rotor is rotated at a higher speed because of the slits. The form of the slits may be selectively varied according to desired characteristics of the ultrasonic motor.