Abstract: A rear side of an operator's cabin body is resiliently supported by a rubber mount, and a front side of the operator's cabin body is resiliently supported by a spring mount, of which a spring constant is set to be smaller than that of the rubber mount. Accordingly, a vibration transmissibility of pitching transmitted from a revolving frame to the operator's cabin body can be kept small, and pitching is damped by an oil damper which constitutes the rubber mount. Further, bounce and rolling transmitted to the operator's cabin body are converted into pitching for attenuation of vibration.

Abstract: A crawler belt drive apparatus which can reduce meshing noises of drive sprocket and crawler belt in a reliable manner over a long period of time. An annular link guide member is provided on a housing of a reducer concentrically with the drive sprocket. As bushes of the respective track links of the crawler belt are meshed with the drive sprocket, the link guide member is held in sliding contact with inner end faces of the track links to maintain a clearance constantly between each bush and a bottom of the drive sprocket, thereby preventing the bushes from directly hitting against the bottom of the drive sprocket to suppress meshing noises or vibrations effectively.

Abstract: The present invention relates to an acoustic microscope system having an ultrasonic probe that is driven with a high-frequency burst signal to radiate an ultrasonic signal and that detects the resulting reflected and irradiated waves, a Z-axis moving device that updates the vertical distance Z between the probe and a material of interest for each sampling position, and device for constructing a V(z) curve from the reflection signals obtained at respective sampling positions. The ultrasonic probe of the invention is provided with an acoustic lens, a first ultrasonic transducer for receiving a leaky surface skimming compressional wave reflected from a sample material on one side of the acoustic lens, and a second ultrasonic transducer also provided on the side of the acoustic lens for receiving a leaky surface acoustic wave.