Marathon Letourneau Company

Letourneau Technologies, Inc.

Letourneau, Inc.

Dwight Baker

Ronald A Johnston

Gary L Nelson

Nelson L Stoldt

Peter J Bradley

Paul K Schufeldt

Erwin F Stoldt

Richard D Baney

Glenn A Shankle

Paul L Kelsey

A heavy duty wheeled vehicle for an industrial environment is electrically driven by one or more switched reluctance motor traction drive system connected to the wheels. The switched reluctance motors are powered by an electrical generator that is driven by an engine, such as a diesel engine, which may run at a substantially constant RPM. A digital control system provides operator displays and controls power conversion from the generator, as well as providing maintenance and control functions for the switched reluctance motors. A heavy-duty hoisting apparatus electrically drives a hoisting mechanism using an SR motor, providing power for lifting a load. The heavy-duty hoisting apparatus may include an engine and generator or provide power to the SR motor from an external source.

Vehicle for materials handling and other industrial uses

An improved method and apparatus for powering and controlling the operation of large diesel-electric off-road haulers of the type in which hauler drive wheels are propelled and retarded by DC electric wheel motors powered from on-board generators, optionally supplemented by DC power, from external trolley lines. In the disclosed system, thyristor-type converters connected into the system AC power grid are used to receive supplemental external power from DC trolley lines and supply it into the AC power distribution grid in the propel mode. The use of such thyristor-type converters makes possible the use of supplemental trolley line power without provision of separate switching or control gear to operate the DC wheel motors when trolley line power is received. Thyristor-type converters also may be used to supply current generated by wheel motors in the retarding mode to retarding resistors, making possible the use of the initial electrical power generated by the wheel motors to replace load requirements of the diesel engine, resulting in substantial fuel savings.

Method for propelling and retarding off-road haulers

An improved method and apparatus for powering and controlling the operation of large diesel-electric off-road haulers of the type in which hauler drive wheels are propelled and retarded by DC electric wheel motors powered from on-board generators, optionally supplemented by DC power, from external trolley lines. In the disclosed system, thyristor-type converters connected into the system AC power grid are used to receive supplemental external power from DC trolley lines and supply it into the AC power distribution grid in the propel mode. The use of such thyristor-type converters makes possible the use of supplement trolley line power without provision of separate switching or control gear to operate the DC wheel motors when trolley line power is received. Thyristor-type converters also may be used to supply current generated by wheel motors in the retarding mode to retarding resistors, making possible the use of the initial electrical power generated by the wheel motors to replace load requirements of the diesel engine, resulting in substantial fuel savings.

Method and apparatus for propelling and retarding off-road haulers

A method and apparatus for load weight determination of the truck including the steps of loading the truck, sensing the pressure of the tilting cylinders to determine the amount of load, indicating the load weight, providing feedback on the affect of variations in the center of gravity of load to correct the load weight determined and providing a corrected load weight. The apparatus includes a tilting bed truck with the bed hinged to the truck frame and tilted to its dumping position by tilting cylinders, a sensing device for sensing the pressure in the tilting cylinders when they are supporting the bed above its support pad, a data processor having data on truck loading and receiving information on the pressure sensed by the sensing device and having an output to indicating devices of the load weight.

Truck load weighing method and apparatus

Growing community of inventors

Longview, TX, United States of America

Dwight Baker