Abstract: An acoustic transducer comprising a housing, and first and second stacks of ransduction plates disposed within the housing for engaging opposed wall portions of the housing, the first and second stacks being adapted to be held in compression between the housing opposed wall portions. A threaded stud extends from the first stack to the second stack, and a nut is threadedly engaged with the stud and adjacent one of the stacks. Movement of the nut on the stud operates to move the stacks toward the housing walls, respectively, to compress the stacks, and operates to relax compressive force on the stacks to enable withdrawal of one of the stacks and replacement thereof.

Abstract: A weld joint test fixture for testing the strength of a weld joining seve members forming a test specimen is provided. The fixture includes a base which supports the test specimen and an attachment for applying a testing force to the test specimen while the test specimen is supported by the base. The fixture further includes holding elements attached to the base for holding the test specimen on the base during the application of the testing force. The holding elements preferably engage one of the members forming the test specimen without engaging another of the members. The fixture may also include the holding elements being designed to oppose the testing force substantially only by forces directed in a plane parallel to the applied testing force.