Abstract: In ultrasonic equipment for generating section images, wherein a sector of a section surface is scanned, the angle of swing of the sound head carrier and the angular width of the sector-shaped section image can be adjusted to different values by adjusting means. For this purpose a crank mechanism is provided, which comprises a connecting rod, which is pivoted on an axis spaced from the geometric axis of rotation of the motor. The connecting rod is mounted in a bearing member, which is disposed adjacent to the axis of rotation and which is pivoted to the sound transducer head carrier on a transverse axis. The adjusted angle between the axis of the connecting rod and the axis of rotation of the motor and the angle of swing of the sound transducer head carrier can be adjusted by an alteration of the ratio of the effective length of the connecting rod to the distance from the axis of the motor to that end of the connecting rod that is nearer to the motor (FIG. 1).