US Patent 9821865 Compact pulling apparatus

The compact pulling apparatus includes a watertight elongated housing extending along a longitudinal axis and a track disposed around the housing along its longitudinal axis. The track enables the apparatus to move when rotatably driven around the housing. Depending on the implementation, the apparatus can include a generator/motor to selectively produce electricity which can power external equipment and rotatably drive the track, and/or a fuel-power engine. The apparatus further includes a power train assembly by which the rotating output power is transmitted from inside to outside the housing by the power train assembly using at least one rotatable shaft section sealingly extending across a corresponding one of the walls of the housing.