Abstract: A horn for vibratory solid-state ultrasonic welding of metals and similarly-behaved materials “self-levels” to produce wide continuous seams or large-area spot-welds between delicate workpieces without damage, even if the workpieces are not perfectly flat and parallel to the nominal toolface angle. The horn toolface flexes under pressure to conform to skew-angled workpieces because it is disposed on a tool head supported by a tool neck cut from the tool body. The tool head, the tool neck, or both are anisotropically compliant. When resonances are properly optimized for typical VSS modes of vibration, atypical but useful localized modes are excited at the compliant toolface edges, actually intensifying the bond energy where one might normally expect unwanted damping. Various design approaches optimize the characteristics of the tool head and tool neck to various materials and bonding configurations. The horns can be configured for use with existing ultrasonic welders.

Abstract: An electrostatic device has a fixed electrode and a flexible-sheet-variable electrode mounted adjacent thereto and insulated therefrom. Fixedly spaced from a portion of the variable electrode is a third electrode to provide a fixed capacity therebetween. A voltage applied between the fixed and third electrode activates the device, and direct ohmic contact to the delicate variable electrode is not necessary.