Abstract: An unbalance vibrator having a shaft 2, with a flyweight 3 rigidly connected thereto, which shaft 2 is mounted in a bearing housing 1, comprises on both sides of this connecting flyweight movable flyweights 5 with flyweight bodies 6 nearly semicircular in cross section and guiding rings 7 nearly semicircular in cross section. The shaft 2 comprises a radial bore on diametrically opposite sides, into which a dog 8 is screwed, and a blind bore 11, into which a locking member 12 is retracted by action of a spring 17. The radial bore 3 and the blind bore 11 are angularly spaced by 90.degree. with respect to the center plane of the flyweight 3 rigidly connected. When the shaft 2 is rotating, the locking member 12 extends from the blind bore 11, such that the movable flyweights 5 are held between the dogs 8 and the locking members 12. The locking members 12 are subjected to hysteresis and are retracted at a rotary speed, which is lower than the loading rotary speed.

Abstract: An ergonomically advantageous operator's seat and controls arrangement for tandem road rollers comprises on the transverse center line of an operator's platform operator's seats arranged side by side and rotatable about vertical axes. A control stick pivotable in two mutually orthogonal directions is located on the longitudinal center line of the operator's platform in the middle between the operator's seats. Two steering devices are mounted with their steering columns rotatable about a longitudinal, central axis on two opposite transverse sides of the platform. Thus by rotation of the seats through 180.degree., four possible seat positions for the operator are achieved. By pivoting the control stick towards the respective occupied seat and by corresponding rotation of one steering device to in front of this seat, all controls are always within easy reach of the operator.

Abstract: An eccentric vibrating machine which includes parallel shafts each carrying an eccentric mass. A gear rotatably journalled on a first of the shafts is drivingly connected to the second shaft for mutual rotation of the gear and second shaft. A shifting coupling is mounted on the first shaft and is selectively engageable with the gear at multiple angular positions around the gear to couple the first shaft to the gear and thereby selectively vary the phase angle relationship of the eccentric masses carried on the two shafts. A manual shifting control device is carried on the first shaft, and can be manually actuated to selectively engage the shifting coupling with the gear.

Abstract: A position sensor includes first and second parts rotatable relative to each other. The first part includes first and second half-ring conductors insulated from each other. The conductors define a sliding surface and the ends of the conductors are spaced to define a slot interrupting the sliding surface. The second part includes a spherical ball closely received in a bore normal to said sliding surface. A spring resiliently urges the ball into said slot to make contact between the two conductors.