Patent ID: 7487607
Filing Date: 2009-02-10
Classification: E01H

Abstract:
1. A heating system for heating the hydraulic fluid of a hydraulic unit used with a power source and having a reservoir for retaining hydraulic fluid, the heating system comprising: a heating element located in the reservoir; a switch having an off position, a booster position and an operating position; a power line for connecting the power source to the sch; a booster line connected to the switch and being connected to the power line with the switch in the booster position; a booster relay connected to the booster line; a return line connected to the relay and to the power source; and a booster heater line connected to the booster relay and to the heating element; an operating line connected to the switch and being connected to the power line with the switch in the operating position; an operating relay connected to the operating line, the operating relay being connected to the return line; and an operating heater line connected to the operating relay and to the heating element, a resistor being located in the operating heating line between the operating relay and the heating element.