Abstract: A fuel injector for delivering fuel to an engine in which a housing of the injector has an internal fuel chamber and at least one exhaust port in fluid communication with the fuel chamber. A valve member is moveable relative to the housing between a closed position in which fuel within the fuel chamber is inhibited against exhaustion from the housing, and an open position in which fuel is exhaustable from the housing. An ultrasonic waveguide is separate from the housing and valve member, with substantially the entire ultrasonic waveguide disposed within the fuel chamber to ultrasonically excite fuel within the fuel chamber prior to the fuel exiting through the at least one exhaust port in the open position of the valve member. An excitation device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

Abstract: An ultrasonic liquid delivery device in which a housing of the device has an internal chamber and at least one exhaust port in fluid communication with the internal chamber of the housing. A valve member is moveable relative to the housing between a closed position in which liquid is inhibited against exhaustion from the housing via the at least one exhaust port, and an open position in which liquid is exhaustable from the housing via the at least one exhaust port. An ultrasonic waveguide separate from the housing and valve member is disposed at least in part within the internal chamber of the housing to ultrasonically energize liquid within the internal chamber prior to liquid being exhausted from the housing in the open position of the valve member. An excitation device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

Abstract: A fuel injector for delivering fuel to an engine in which a housing of the injector has an internal fuel chamber and at least one exhaust port in fluid communication with the fuel chamber. A valve member is moveable relative to the housing between a closed position in which fuel within the fuel chamber is inhibited against exhaustion from the housing, and an open position in which fuel is exhaustable from the housing. An ultrasonic waveguide separate from the housing and valve member is disposed at least in part within the fuel chamber to ultrasonically excite fuel within the fuel chamber prior to the fuel exiting through the at least one exhaust port in the open position of the valve member. An excitation device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

Abstract: The present invention provides a method of manufacturing piezoelectric transducers that improves performance by reducing the mechanical losses in the component interfaces. The method involves the epoxy impregnation and encapsulation of the components within the piezoelectric stack assembly. Impregnation is achieved by capillary action that results in a chemical bond. The encapsulation method results in an epoxy conformal coating that provides a high degree of protection from harsh operational environments and reduces the risk of high voltage electric breakdown.

Abstract: A fuel injector for delivering fuel to an engine in which a housing of the injector has an internal fuel chamber and at least one exhaust port in fluid communication with the fuel chamber whereby fuel exits the fuel injector at the at least one exhaust port for delivery to the engine. An ultrasonic waveguide is separate from the housing, and is elongate and disposed at least in part within the fuel chamber to ultrasonically energize fuel within the fuel chamber prior to the fuel exiting through the at least one exhaust port. An excitation device is operable to ultrasonically excite the ultrasonic waveguide. A mounting member interconnects the waveguide to the housing, with the mounting member configured to substantially vibrationally isolate the housing from the waveguide.

Abstract: Ultrasonic waveguides having improved velocity gain are disclosed for use in ultrasonic medical devices. Specifically, the ultrasonic waveguides comprises a first material having a higher acoustic impedance and a second material having a lower acoustic impedance.

Abstract: Methods for manufacturing ultrasonic waveguides having improved velocity gain are disclosed. Additionally, methods for manufacturing ultrasonic medical devices including the ultrasonic waveguides are disclosed. Specifically, the ultrasonic waveguides comprises a first material having a higher acoustic impedance and a second material having a lower acoustic impedance.

Abstract: The present invention provides for single use ultrasonic transducers for use in surgical and dental applications. Specifically, the invention provides transducers comprising one or more of the following features, an active piezo ceramic material that contains less than 2% lead; piezo materials with a low Curie temperature, a high compressive bias force applied to the piezo ceramic elements, a bias bolt sub-assembly that includes a component assembled with a low-temperature glass-transition point filled epoxy material, and/or a permanently attached end effector with a self-locking taper.

Abstract: The present invention relates to methods for velocity control of transducers that can compensate both for age related changes as well as the more immediate changes that occur during operation. In one aspect of the invention, the non-motional reactive current is measured at two predetermined frequencies, one below (Ilf) and one above the resonance frequency (Ihf). A correction factor is calculated from these measured currents is used to maintain a specified value of end effector velocity or displacement. In another aspect of the invention, methods are provided for the detection of secondary resonances that could be indicative of end effector fault conditions.

Abstract: The present invention provides a piezoelectric assembly, comprising at least one piezoelectric element and at least one electrode assembled to lie between an energy delivery member and a pre-loading member, characterised in that the electrode further comprises, where in contact with the piezoelectric element, a coating of a material which is sufficiently compliant so as to deform under the pre-loading stress and conform to the surface of the piezoelectric element.

Abstract: An ultrasonic energy amplifier. The amplifier comprises a delivery horn having a solid proximal portion and a hollow distal portion. The hollow distal portion has substantially less cross-sectional area than the solid proximal portion. Ultrasonic energy is transmitted sequentially through the proximal and distal portions and its velocity is amplified because of the lower cross-sectional area of the distal portion.

Abstract: Handpiece apparatus is provided for disruption and removal of tissue, tumors, bone, cartilage, calculi or the like which includes an arrangement of piezoelectric crystals and a heat sink in order to control crystal temperature despite interruption of cooling irrigation flow through the handpiece.

Abstract: An ultrasonic energy amplifier. The amplifier comprises a delivery horn having a solid proximal portion and a hollow distal portion. The hollow distal portion has substantially less cross-sectional area than the solid proximal portion. Ultrasonic energy is transmitted sequentially through the proximal and distal portions and its velocity is amplified because of the lower cross-sectional area of the distal portion.

Abstract: A high power, low frequency flextensional transducer (50) for underwater use comprises a number of spaced piezo-electric element stacks (53) between opposed inserts (51, 52). A Kevlar (registered trademark) compression band (54) is wound around the stacks and inserts and then partly elliptical plaster formers (56) are attached. A filament wound elliptical GRP flexural shell (57) is then wound around the assembly while controlling the tension so as to provide the required pre-stress on the piezo-electric stacks (53) when cured. After curing the plaster formers (56) are removed. End-plates (16) are attached to the elliptical shell (57) to complete the transducer; the shell (11) having a compression bonded layer (61) of neoprene applied, including a peripheral serrated lip seal (62) to seal against the end-plate (16) while permitting flexing of the shell. A device to provide wide bandwidth performance is also disclosed.

Abstract: A high power, low frequency flextensional transducer for underwater use comprises a number of spaced piezo-electric element stacks between opposed inserts. The stacks are placed on the plane through the major axis of an elliptical flexural shell and the inserts are shaped to conform with the elliptical shape. The stacks are assembled with first tapered supports and complementary tapered slides are wedged between the shell inserts and the tapered supports until a required pre-stress is exerted by the shell on the piezo-electric stacks. End-plates are attached to the elliptical shell to complete the transducer; the shell having a compression bonded layer of neoprene applied, including a peripheral serrated lip seal to seal against the end-plate while permitting flexing of the shell. A means to provide wide band-width performance is also disclosed. To extend the range of operational depths the cavity within the transducer is filled with a gas whose vapor pressure can be temperature-controlled.

Abstract: A high power, low frequency flextensional transducer for underwater use comprises a number of spaced piezo-electric element stacks between opposed inserts. The stacks are placed on the plane through the major axis of an elliptical flexural shell and the inserts are shaped to conform with the elliptical shape. The stacks are assembled with first tapered supports and complementary tapered slides are wedged between the shell inserts and the tapered supports until a required pre-stress is exerted by the shell on the piezo-electrical stacks. End-plates are attached to the elliptical shell to complete the transducer; the shell having a compression bonded layer of neoprene applied, including a peripheral serrated lip seal to seal against the end-plate while permitting flexing of the shell. A means to provide wide band-width performance is also disclosed. To extend the range of operational depths the cavity within the transducer is filled with a gas whose vapour pressure can be temperature-controlled.

Abstract: A flextensional sonar transducer assembly includes a stack of piezoelectric elements disposed along a linear axis, a plurality of electrodes disposed between the elements, end pieces disposed at each end of the piezoelectric stack, with the end pieces having outwardly facing, generally arcuate surfaces, a compression band formed into a loop to encircle the stack and end pieces, a flexural shell disposed to circumscribe the compression band to present a generally elliptical side cross-section, with the major axis thereof being generally coincident with the linear axis of the stack, and with the shell being reactively coupled to the arcuate end portions of the compression band, and rod members positioned between the compression band and the arcuate end portions of the band of material for maintaining driving contact between the shell and the end pieces, and for adjusting the prestress compression pressure in the stack. The invention also includes methods of manufacturing the transducer assembly.

Abstract: A flextensional sonar transducer assembly includes a stack of piezoelectric elements disposed along a linear axis, a plurality of electrodes disposed between the elements, end pieces disposed at each end of the piezoelectric stack, with the end pieces having outwardly facing, generally arcuate surfaces, a band of material formed into a loop to encircle the stack and end pieces, a flexural shell disposed to circumscribe the band of material to present a generally elliptical side cross-section, with the major axis thereof being generally coincident with the linear axis of the stack, and with the shell being reactively coupled to the arcuate end portions of the band of material so that a transverse movement of the long sides of the shell causes longitudinal compression or expansion of the elongate means and vice versa, and wedge elements positioned between the shell and the arcuate end portions of the band of material for maintaining driving contact between the shell and the end pieces.