Abstract: A steering mechanism for an excavator or similar vehicle having a pair of steerable wheels and a pair of fixed wheels wherein the steerable wheels are carried by a movable steering fork which is mounted on a circular-shaped rail such that movement of the steering fork around the rail causes steering of the steerable wheels. The axes of rotation of the steerable and fixed wheels remain substantially equidistant from the center of the circle defined by the rail in all positions of the steering fork on the rail. Fluid motors carried by the excavator are operatively connected to the steering fork for moving same around the rail.

Abstract: An excavator includes a vessel-like lower frame having a generally vertical side wall, and a bottom wall that forms a support plate. Wheel means are secured to the lower frame side wall, and an upper frame is mounted on the lower frame for rotation about a vertical axis. The upper frame carries a cabin, and a boom and bucket assembly. The engine and other heavy equipment components for operating the excavator are secured to the underside of the upper frame and rotate therewith, thereby giving the excavator a low center of gravity, and eliminating clutter around the operator's cabin.

Abstract: An excavator has its wheels pivotably mounted on brackets which are adjustably secured to the periphery of the under-frame so that the gauge of the wheel track and their distance to each other can be changed.The present invention relates to an excavator of the kind where the under frame is formed like a big, preferably cylindrical vessel with a plane bottom in order to prevent the excavator from sinking deeply into soft ground.When excavators are moved from one working place to another this is usually done on the public road network. Some excavators are moved by their own motor, while others are trailed by truck. The allowed gauge of track for the wheels of an excavator is limited by the regulations of the road authorities, which implies the disadvantage that the gauge of track is often not sufficient.The object of the invention is to provide an excavator of the kind mentioned above where the above mentioned disadvantage is eliminated.

Abstract: An excavator has its cabin and boom mounted bucket on a rail carriage which may be moved along the excavator frame by means of a first set of hydraulic cylinders. Lifting legs are mounted on the sides of the rail carriage and are associated with a second set of hydraulic cylinders for lifting the under-frame in cooperation with the bucket. The lifting legs and bucket form a 3-point stance when pressed against the ground. In this stance the under-frame may be translated by said first set of hydraulic cylinders and/or turned relative to the upper-frame by motor means. This arrangement allows the excavator to "walk" out of difficult situations.