Abstract: In a vehicle locating apparatus that utilizes Hall effect generators to determine the magnetic heading of the vehicle there is provided magnetic compensation by the placing of a coil around the Hall generators. A current source generator provides power to the coil of such magnitude so as to create a magnetic field which cancels the spurious local magnetic field components. The appratus also includes a set of manual switches to program a constant number into the system. The system incorporates this number to compensate for variable wheel diameters and to allow the selection of variable map scale units. This number is utilized by the system in a division technique that repeatedly subtracts the number or adds the number to the accumulated distance traveled by the vehicle. The location of the vehicle is updated as the vehicle passes a transmitting signpost. Data transmitted to and from the vehicle locating apparatus is in a self-clocking format that reduces oscillator accuracy requirements.

Abstract: In a vehicle locating apparatus that utilizes Hall effect generators to determine the magnetic heading of the vehicle there is provided magnetic compensation by the placing of a coil around the Hall generators. A current source generator provides power to the coil of such magnitude so as to create a magnetic field which cancels the spurious local magnetic field components. The apparatus also includes a set of manual switches to program a constant number into the system. The system incorporates this number to compensate for variable wheel diameters and to allow the selection of variable map scale units. This number is utilized by the system in a division technique that repeatedly substracts the number or adds the number to the accumulated distance traveled by the vehicle. The location of the vehicle is updated as the vehicle passes a transmitting signpost. Data transmitted to and from the vehicles locating apparatus is in a self-clocking format that reduces oscillator accuracy requirements.

Abstract: A closure including a rigid thermoplastic member with a horizontally extending first portion occupying a major portion of the cross-sectional area within the loading aperture which is surrounded by the loading member of the hopper car, a second portion extending upwardly from the first portion which is inwardly adjacent of the interior of the loading member and a third portion extending outwardly from the second portion and overlaying the top of the loading member and underlaying the hatch cover of the hopper car when the hatch cover is in its closed position. Also a flexible plastic member overlaying the rigid thermoplastic member and the loading member and underlaying the hatch cover when the hatch cover is in its closed position.

Abstract: In a vehicle locating apparatus that utilizes Hall effect generators to determine the magnetic heading of the vehicle there is provided magnetic compensation by the placing of a coil around the Hall generators. A current source generator provides power to the coil of such magnitude so as to create a magnetic field which cancels the spurious local magnetic field components. The system includes a set of manual switches for inputting a rotation angle. A variable time delay circuit incorporates this rotation angle to electronically increase or decrease the measured magnetic heading angle. This electronic rotation provides for a method to correct physical misalignment of the heading sensor in the vehicle and to compensate for local magnetic deviation.