Abstract: An elastomer support for a sonar transducer includes a ceramic stack electromechanical driver, a pair of rigid support members, and a pair of elastomer layers disposed between the ceramic stack electromechanical driver and the support members. The elastomer support provides effective mechanical stress reduction in the ceramic stack driver, as well as, a simple, reliable heat dissipation means for the transducer.

Abstract: A seal of flexible waterproof material joins two shells, or a shell and its end plate, which are spaced at their edges to have a separation or gap between them into which the seal material loops. The seal material is attached to each shell, or to the shell and its end plate, to effect a watertight seal at the joint. When one joint edge moves radially with respect to the other edge, a low friction rolling action of the seal material accommodates the motion with low frictional resistance and low energy loss.

Abstract: A shaft mountable, portable, low frequency FM transmission device for comicating rotating shaft mounted sensor information to a stationary platform. It includes a generally cylindrical, dynamically balanced sending unit attached to and encircling the shaft and a remote stationary receiver having a preamplifier and pickup loop encircling but not touching the sending unit. Information from shaft mounted transducers is transmitted from the shaft to the receiver using low frequency FM techniques. Low frequency FM operates at low power which permits use of small batteries containable in a reduced volume, requires minimal receiver electronics, allows undistorted signal transmission at high RPM's and is relatively insensitive to axial and radial shaft movement.