Abstract: The present invention relates to a flextensional transducer device comprising a multi-resonant shell and push-pull driving system for driving the shell so as to provide at least two tunable resonant modes, thereby increasing the operational bandwidth of the device. The push-pull driving system is formed by four rings of active drive material grouped to operate as two opposing push-pull pairs. The shell has a dog-bone configuration with two arcuately shaped interior web portions joined to the pairs of rings, end sections joined to the interior web portions, and a central concave section which functions as the primary radiating surface. Upon application of a desired current to the push-pull ring pairs, the interior web portions are caused to vibrate, which vibrations are transmitted to the end sections and the central concave section.

Abstract: A sealed slotted cylinder includes an active transducer assembly, end caps at each end of the assembly, and a boot fused to the end caps and sealing the assembly. The sealed slotted cylinder is made using a dummy insert and a spacer within the dummy insert for spacing the end caps. A boot material made from an uncured rubber is wrapped around the dummy insert and the end caps. This assembly is placed in a mold that fuses the boot material to the end caps by vulcanizing the uncured rubber material. The mold and dummy insert preferably form longitudinal and circumferential boot roll seals on the boot material. A section of the boot is then removed forming an open region, allowing the dummy insert and spacer to be removed. The active transducer assembly can then be inserted through the open region such that the longitudinal boot roll seal engages and seals the slot in the active transducer assembly and the circumferential boot roll seals engage the end of the active transducer assembly.

Abstract: A piezoelectric composite transducer and method for making same are disclosed. A block of piezoelectric material has a common base and a plurality of uniform-length rods extending from the common base in a parallel spaced-apart fashion to define an array. A first surface region is defined at outboard ends of the rods and a side region is defined about the periphery of the array. Electric conductors extend through the side region, are routed parallel to the first surface region, and are then led substantially parallel to the rods to the first surface region. Spaces between the rods are filled up to the first surface region with a viscoelastic material. The common base of the block is then removed such that a second surface region parallel and opposite to the first surface region is defined. Electrodes are deposited at the first surface region to be in contact with the rods and in electrical contact with the electric conductors.

Abstract: A piezoelectric composite transducer and method for making same are disclosed. A block of piezoelectric material has a common base and a plurality of uniform-length rods extending from the common base in a parallel spaced-apart fashion to define an array. A first surface region is defined at outboard ends of the rods and a side region is defined about the periphery of the array. Electric conductors extend through the side region, are routed parallel to the first surface region, and are then led substantially parallel to the rods to the first surface region. Spaces between the rods are filled up to the first surface region with a viscoelastic material. The common base of the block is then removed such that a second surface region parallel and opposite to the first surface region is defined. Electrodes are deposited at the first surface region to be in contact with the rods and in electrical contact with the electric conductors.