Abstract: A relatively massive annular body is driven in radial-mode resonant oscillation by an ultrasonic driver that is fixed to the periphery of the annular body, with the axis of its ultrasonic drive oriented for intersection with the central axis of the annular body. A selected chucking device within the bore of the annular body is adapted to engage part of a prosthetic device, to which the resonant oscillation is imparted, for melting bone cement and for severing bony ingrowth into the prosthetic, thus permitting immediate retraction of the prosthetic from its pre-existing implantation in a living bone.

Abstract: An apparatus producing an aperture through a workpiece of brittle material such as ceramic or glass which includes a piezo electric transducer to generate longitudinal vibrations at a frequency within the range 20-40 kHz, and transmit the vibrations to a tip adapted to contact the workpiece. Additionally a motor generates small amplitude movements of the tip at a frequency in the range of 10-100 Hz in a plane transverse to the direction of the longitudinal vibrations.

Abstract: The apparatus comprises a piezoelectric vibrator adapted to generate ultrasonic energy which is transmitted through an output section 1 to a plastics head 6. The shape of the head 6 may be varied to suit whichever part of a body on which it is to be used. The material and shape of the head 6 is chosen to allow accurate control of frequency and amplitude of the ultrasonic energy. The preferred ultrasonic frequency is in the range of 20-120 kHz.

Abstract: A relatively massive annular body is driven in radial-mode resonant oscillation by an ultrasonic driver that is fixed to the periphery of the annular body, with the axis of its ultrasonic drive oriented for intersection with the central axis of the annular body. A selected chucking device within the bore of the annular body is adapted to engage part of a prosthetic device, to which the resonant oscillation is imparted, for melting bone cement and for severing bony ingrowth into the prosthetic, thus permitting immediate retraction of the prosthetic from its pre-existing implantation in a living bone.

Abstract: A tool for use in removing plastics material from a hole comprises a work surface adapted to contact the material. A piezo-electric transducer is operatively connected through a work horn and causes the work surface to vibrate ultrasonically and thereby to heat locally the plastics material. A cavity is adapted to receive heated plastics material. The cavity has communication with a working zone adjacent the work surface. The work surface comprises an elongate boring member and rearwardly thereof a substantially annular cutting edge; the working zone communicates with the cavity via apertures disposed between the boring member and the annular cutting edge.

Abstract: A method of cutting a brittle workpiece comprises applying to the surface of the workpiece a pointed tool, applying high frequency vibrations in a longitudinal direction to the tool, and moving the tool along a line to be cut of the workpiece while applying substantially steady longitudinally directed pressure to the tool. Stress is thereby applied to the workpiece as a combination of short impulses and steady direct stress and the breaking stress of the material would be attained coincident with the peak oscillatory stress. Crack propagation would therefore proceed by a series of stepwise fractures induced by successive cyclic stress peaks, resulting ultimately in the separation of the workpiece into two pieces.

Abstract: A piezo electric ceramic transducer 1, a coupling horn 2 and a work surface 11 are connected a work horn 3. The work surface is ultrasonically vibrated and heats locally plastics material, causing it to flow through holes 12 in the work surface 11 to a space behind. The material can be removed when the tool is removed from the hole. The tool is particularly useful old cement from bones when revising a joint prosthesis.

Abstract: An infuser comprises movable screen means, which is preferably a continuous mesh belt (1) passing around rollers (2). Infusible solid and infusing liquid are deposited onto the screen means (1) and means (5) below the screen collect the infusion. A piezo electric sandwich transducer (9) is provided for imparting ultrasonic vibrations to the screen to cause vibration of the screen means to aid cleaning thereof.

Abstract: There is disclosed a control valve having an inlet 24, an outlet 26 connected a a valve cavity 23. The valve includes an armature 31 of a solenoid 32, movement of which opens a valve seal 28 seated in valve seat 27. A piezoceramic transducer 21 transmits ultrasonic vibrations through a tapering output section 22 to the valve cavity, whereby cavitation is induced in liquid therin to cause cleaning of the surfaces.

Abstract: There is disclosed a transport system for material in powdered, particulate, granular or the like form. A generally horizontal flow channel extends from an inlet (20) to an outlet (11) for the material. An ultrasonic standing wave is set up in the body (10) surrounding the flow channel by means of a piezo-ceramic transducer (12). The standing wave is arranged to have an antinode at or near the inlet and a node at or near the outlet whereby the material flows along the channel.