Abstract: An ultrasonic resonant vibrator comprising an ultrasonic vibration magnetostrictive transducer, and a resonant member having a proximal end and a distal end for transmitting ultrasonic vibrations to an operating member which is part of the resonant structure. The vibrator comprises an integral substantially rigid column having a central axis with fins extending radially relative to said axis and having a longitudinal hole defining a tunnel centered along the central axis, wherein at least part of the resonant member is located within the tunnel; and a surgical handpiece incorporating such a vibrator.

Abstract: A device for rotating a member at relatively low rotational speeds is particularly useful for rotating a brush-type tooth polisher on an insert for an ultrasonic dental prophylaxis unit. The device comprises a vibrator which ultrasonically vibrates longitudinally and has a driving tip end portion which converts the longitudinal vibrations into elliptical motion. The elliptically moving driving tip tangentially engages at least one rotatable roller during an arc of the elliptical motion to rotate the roller. A speed reduction device couples the roller to a rotary polisher to rotate the polisher at a reduced speed. Preferably, the speed reduction device also isolates the axial and radial thrust applied, in use, to the polisher from the roller which receives some radial thrust from the vibrator. This reduces the bearing requirements for the polisher and roller. Also preferably, the roller, speed reduction and polisher elements are assembled as a unit separable from the vibrator for ready replacement.

Abstract: A device using longitudinal ultrasonic vibrations for rotating a shaft at relatively low rotational speeds is particularly useful for rotating a brush-type tooth polisher on an insert for an ultrasonic dental prophylaxis unit. The device has a sleeve which supports the rotatable shaft and a vibrator. A disc is normal to the axis of rotation of the shaft and connected to the shaft for rotation. A transducer at one end of the vibrator responds to excitation for producing longitudinal ultrasonic vibrations in the vibrator, and the other end of the vibrator which is urged against the disc with a constant force converts the longitudinal vibrations into elliptical motion to engage one face of the disc during an arc of the elliptical motion. This imparts substantially only pulses of tangential driving force and normal vibrational forces to rotate the disc and shaft unidirectionally. In one preferred embodiment, the vibrator has a single driving pad urged against the disc.

Abstract: A method and apparatus are provided for measuring the magnitude of spherical hardness testing indentations in solid surfaces by scanning the indentations with a light beam. Scanning is achieved by tilting the beam in one or several planes perpendicular to the testpiece surface through a point which is the center of rotation for the beam tilting as well as the center of curvature of the indentation area in the plane of tilting. At least the part of the indenter making contact with the indented surface is spherically shaped, and the scanning light spot follows an arcuate path in the indentation being measured. The scanning light beam is sent through a transparent indenter, or scanning is carried out directly on the indentation after removal of the indenter.

Abstract: Methods and apparatus are provided for determining the magnitude of hardness testing indentations by scanning the indentations with a light source with or without an external load being applied while the scanning takes place. The intensity of the reflected light from the surface under test is measured utilizing a light-senstive surface surrounding the measuring field. One or more diameters or the entire indentation is scanned and measured to determine the magnitude of the indentations.

Abstract: Surface properties, such as, hardness, of a test piece are determined by holding a mechanical resonator, for example, in the form of a sensor rod against a surface of the test piece with a static force sufficient to maintain steady contact with the test piece surface at a contact surface on the sensor rod shaped to provide an increasing area of contact with increasing plastic and/or elastic indentation or deformation of the test piece surface, exciting the test piece into vibration with a frequency which is varied so that the vibrations transmitted from the test piece to the sensor rod will cause the latter to attain a state of resonance, for example, as indicated when a maximum amplitude of the vibration of the sensor rod is sensed, measuring the amplitude of vibration of the excited test piece at a region of the latter which is adjacent to, but outside of the area of contact of the test piece with the contact surface on the sensor rod, for example, by means of an auxiliary sensor, and further varying the fr