Abstract: A speed control system for small medical motors. The system comprises a drive voltage regulation circuit, a current detection circuit which generates a detection signal in accordance with motor current, a voltage detection circuit which generates a detection signal in accordance with motor voltage, and a speed control circuit which controls the drive voltage regulation circuit in accordance with the detection signals of both detection circuits. With this system, the detection signal of the current detection circuit is positive-fed back, and the detection signal of the voltage detection circuit is negative-fed back to the speed control circuit to keep motor speed constant by effectively coping with abrupt load fluctuation.

Abstract: A dental handpiece having therein a non-contact rotating speed detection device which includes an electromagnetic induction pulse generator including a permanent magnet provided close to the rotor in the head of a dental handpiece and a coil wound around the permanent magnet, and a rotor made of a magnetic material provided with recesses and/or projections around its circumference. The handpiece according to the invention facilitates to accurately detect rotor speed by detecting a pulse voltage proportionate to the rotation speed and therefore is useful for dental treatment and experiments.

Abstract: This invention relates to a face bow for a mandibular motion diagnostic device and more particularly to a face bow as a component of a device for measuring a patient's mandibular motion and reproducing it precisely by the use of a mandibular model on the basis of the measured data. The face bow is attached in a fixed positional relationship to the patient's mandible as measurement is taken of the motion thereof and is shifted onto the mandibular model upon completion of the measurement so that the patient's dental arch in its actual position is precisely reproduced in the mandibular model.

Abstract: A mandibular motion reproducing device wherein a mandibular model supporting plate on which a mandibular model is fixed is deemed as a rigid plane, three points contained in this rigid plane are selected and marked, three reference points for reproduction are set each corresponding to one of the marked points and in a predetermined dimensional relationship therewith, drive means capable of shifting the individual reference points for reproduction along the coordinate axes of X, Y, Z respectively are connected therewith, the drive means have six alternative driving directions including the orthogonal X, Y and Z directions and are individually driven by inputting position coordinate information obtained from a measuring system and the resulting motions of the reference points for reproduction are synthesized for causing the rigid plate constituting the mandibular model supporting plate to undergo three-dimensional motion.

Abstract: A structurally simplified dental service equipment generally usable for collective dental examination and practical exercises in dental hygienist training schools, wherein the equipment is easily transportable to any places in a disassembled form and assembled on the scene of dental examination, being advantageously employable as advantageously just as existing dental service equipment in use at most dental clinics.

Abstract: A dental diagnostic device is disclosed, wherein the mandibular motion is created as that which results from synthesis of three-dimensional motions of three points to be measured. It is converted into movement of three reference points for reproduction corresponding to the individual points to be measured and the motion resulting from synthesis of the three-dimensional motions at the respective reference points for reproduction is reproduced in or by the use of the mandibular model. Hence no approximate computing processing or the like is needed, there is no room for errors except those in the measuring and reproducing systems and theoretically it is possible to reproduce with a high precision the patient's mandibular motion by the use of a three-dimensional model of the mandible.

Abstract: This disclosure relates to a DC high voltage generator disposed on the base which is adapted to freely move into and out of a casing and on which a high voltage transformer circuit is disposed. The transformer circuit comprises a variable magnetic leak transformer and capacitor type multiple boosting circuits disposed separately on the right and left sides of the transformer. The high voltage generator is compact, easy of maintenance and inspection and is excellent in insulating countermeasures and in efficiency.

Abstract: This disclosure relates to a driving and water pouring control device for dental air-drive handpiece. According to the control device, there is incorporated a water pouring on-and-off valve means into an air feed passageway for driving a turbine so as to close and open the valve means by using part of air inside the passageway and to concurrently provide the valve means with a function of preventing water from dropping when pouring of water is stopped. The disclosure also relates to a device capable of compactly assembling therein device members.

Abstract: The present invention relates to a medical X-ray radiation power supply apparatus wherein a DC-operated switching circuit is connected at the primary side of a high voltage transformer, and a comparator circuit compares the voltage predetermined by a tube voltage setting circuit with an actual tube voltage detected by a tube voltage detector circuit, then the gain of a comparison voltage is raised so that the actual tube voltage can quickly reach the predetermined tube voltage value, thereby tube voltage errors, which are caused by short photographing time in a medical or breast X-ray photographing apparatus, are eliminated.

Abstract: This disclosure relates to a system for supplying a stable DC high voltage to a load by resonantly driving a high voltage transforming circuit comprising a VLT and a capacitor type multiple boosting circuit. The system includes a VLT, a capacitor type multiple boosting circuit and a pulse-amplitude feedback control circuit designed to detect supply voltage to load, to compare the detected voltage with reference voltage and to control the voltage of the control winding of VLT by using the deviation produced by the comparison as a control signal.

Abstract: This disclosure relates to the improvement of a tomograph for photographing the entire jaws which is designed to make an X-ray photograph of a curved plane section of an object by changing the rotating output of a motor for driving a rotary arm by using an eccentric cam means to control a film feed speed by the rotary output thus change. This apparatus includes a tachogenerator for converting the rotating output of the rotary arm driving motor into an electric output, a voltage shunting means for shunting the output of the tachogenerator to three paths, a reference point correction circuit and a changeover resistance means, and is capable of providing a clear X-ray photograph of a patient in the range of adults to children without necessity to change the eccentric cams nor the position of the patient.

Abstract: A drive control circuit for a dental treatment table with a hydraulic cylinder for elevating and lowering a seat comprising a hydraulic drive circuit equipped with a hydraulic pump, a first hydraulic valve for elevating said cylinder, and a second hydraulic valve for lowering said cylinder, and a hydraulic pump operation circuit equipped with an air switch, a first air valve for controlling said air switch and said hydraulic valve for elevating said cylinder, and a second valve for controlling said hydraulic valve for lowering said cylinder. The drive control circuit may further comprise a second cylinder for tilting a backrest which can be controlled by the hydraulic drive circuit and the hydraulic pump operation circuit.

Abstract: An air operated oil pressure control valve wherein the inlet port and the outlet port for oil are provided in the valve body at a position wherein they face each other with a normally closed valve port located in between. When compressed air is introduced into the valve body, the valve port is opened, allowing the oil pressure to pass through the valve.

Abstract: A foot controller for controlling dental instruments of the type including pedals for controlling the rotational speed of a handpiece. The foot controller is designed such that the front part of the pedal is used for controlling high-speed rotation and requires a small tread pressure; while the rear portion of the pedal is to be used for controlling low-speed rotation and requires a large tread pressure.

Abstract: The disclosure relates to a gate driving circuit for a depletion type, static induction transistor, including a capacitor coupled between the emitters of complementary-connected NPN and PNP transistors and the SIT gate, high value resistor parallel-connected to a series connection of a diode and a resistor between the SIT gate, and a negative gate voltage source.

Abstract: The disclosure relates to improvements in a hydraulically-actuated control device used in an operation unit of treatment chair and the like in an interlocking relation with reciprocating movement of a hydraulic piston. The device is of the construction in which two control valves slow in closing and opening operation are disposed in the oil supply and discharge passages leading to a hydraulic cylinder having a hydraulic piston therein so as to prevent shock in starting and stopping of the operation unit by controlling opening and closing of the two control valves and operation of the hydraulic pump disposed in the oil supply passage.

Abstract: A chuck device for a dental handpiece comprising fixedly mounting a front collar inside a rotor at the end thereof for the dental handpiece and threadedly and detachably fixing a cartridge chuck behind said front collar inside of said rotor, said cartridge chuck comprising a substantially cylindrical chuck case provided at the rear end with an engagement portion for detachably connecting a cutting tool thereto, a synthetic rubber chuck body press inserted into the end side of said case, and a rear collar fixedly mounted behind said chuck body inside said case.

Abstract: This disclosure relates to an occlusion pressure image display system which is designed to make visual display of the output signals of the occlusion pressure sensor in the form of a black-and-white or color brilliance image on a CRT screen. The system comprises in combination, a novel occlusion pressure sensor designed to convert information on the occlusion pressure of the teeth into electric signal output by mere biting with the teeth and a raster scanning type CRT display.

Abstract: The disclosure relates to a dental treatment chair which contains in its backrest a dispensing controller for compressed air and water to be distributed to the dental instruments of the chair; the controller includes a distributing block for air and water, air-pressure-operated on-off valves, and couplings to connect flexible connecting pipes connected to the instruments to the supply source side. The chair can reduce the number of compressed air and water pipes leading from the seat body to the backrest of the chair and can diminish the distance of piping between the dental instruments and the dispensing controller to reduce passage resistance.