Abstract: An ultrasonic touch panel is offered which can detect whether there is a touch, at an improved accuracy without the need to adjust the detection sensitivities of individual piezoelectric bodies separately. The piezoelectric bodies have comb-like electrodes that excite ultrasonic waves. A sealant is applied to those of the side surfaces of the piezoelectric bodies which intersect with the direction of propagation of the excited ultrasonic waves. This suppresses reflection of the ultrasonic waves, thus attenuating ultrasonic waves propagating to the intersecting side surfaces. Generation of parasitic waves which would normally be caused by reflection of ultrasonic waves is prevented.

Abstract: A leg clamping device for a jack up platform having legs extending through the platform and a rack attached to each of the legs therealong and meshing with a drive pinion mounted on the platform. The leg clamping device comprises a plurality of clamp pieces engageable in the furrows of the rack, a bearing body fixedly mounted on the platform and supporting the clamp pieces individually movably toward or away from the rack, and locking means each provided for each of the clamp pieces individually for releasably locking the clamp piece in engagement with the rack furrow.