Abstract: A control system is provided for turbines in the utility part of an industrial plant using cogeneration so that control is maintained over the relative quantities of steam supplied to a common steam header from both the back pressure and the extraction turbines where the header supplies process steam at a predetermined pressure. The steam flow from a stage of the extraction turbine is controlled to maintain the header pressure at its desired value. The steam flow thus controlled is measured and a control means is provided to control the steam flow from a back pressure turbine supplying the same header so as to maintain a predetermined relationship between the two steam flows while maintaining electrical generation from the generators driven by the turbine at a maximum consistent with maintenance of an adequate control range for the header pressure control.

Abstract: The propulsion system includes a battery powered or combustion powered prime mover and a secondary or auxiliary mover. When the prime mover is battery powered, the secondary mover is controlled so as to optimize the use of the electrical energy stored in the batteries, while using the secondary mover, when necessary, to supply auxiliary power when required for vehicle performance. This is done by keeping the prime mover operating, primarily, in the low to moderate current range, where energy loss in the battery is low and controlling the secondary mover to supply as much power as is necessary to keep the battery drain as near as possible to a preselected threshold value. When the prime mover is combustion powered, the secondary mover is similarly controlled to keep the prime mover within the torque range of most efficient operation.

Abstract: A load sharing arrangement for a multiple engine power plant operating to supply power to a common load wherein the power output of each engine is proportional to the amount of fuel supplied thereto. A pneumatic speed setting designated by the power plant operator is directed so as to control the power output of one of the engines (master), and remotely located control system sensitive to the power output of each of the engines, adjusts the power output of the other engine (slave) so that the common load is equally shared at the designated speed setting.

Abstract: An off-highway earth-moving vehicle of the scraper type which includes a tractor section and scraper section interconnected by a draft frame providing rolling rigidity, each section having a pair of ground-engaging wheels. A floating axle assembly is provided on the tractor section permitting independent movement of the tractor wheels in the following of ground contours. The scraper section is driven by a first engine having a first torque converter coupled to the scraper wheels. The tractor section is driven by a second engine having a second torque converter coupled to the tractor wheels. The sections of the vehicle are so proportioned in size and weight that the weight applied to the scraper wheels under both loaded and unloaded conditions is approximately twice the weight applied to the tractor wheels and the torque converters in the sections are so proportioned that at normal operating engine r.p.m. the power supplied to the scraper wheels is approximately twice the power supplied to the tractor wheels.

Abstract: Two turbine engines are connected to a common gear box to drive a common load, such as a helicopter rotor, and circuitry is provided for controlling the two mechanically intercoupled engines in order to provide: (1) individual temperature shutoff for the engines, (2) limitation on the maximum total torque supplied by the two engines to avoid exceeding the power handling capability of the gear box for the associated load, (3) speed control for the engines, and (4) substantially equal sharing of the torque load by the two engines. By suitably combining the signals which require analysis, and supplying a single properly conditioned signal to the fuel control unit of each engine, tight control without oscillation or cycling may be achieved. Notch filtering to avoid reinforcement of mechanical resonances, and a variable response characteristic depending on the magnitude of the error signal may be included in the circuitry.

Abstract: Two gas turbine helicopter engines are coupled together for isochronous operation to supply a common load. A control circuit assures that the power delivered to the common load is equally divided between the two engines. The torque of each engine is detected and the torques are compared to established control signals for the engines.