Patent ID: 6499535
Filing Date: 2002-12-31
Classification: B23Q,F25B,F25D

Abstract:
A control loop system for maintaining the temperature of an operating tool at a selected level within a substantial temperature range that includes levels above and below the ambient, using a chilled pressurized refrigerant and a thermal transfer fluid, comprising:means defining a control loop for a thermal transfer fluid communicating in thermal interchange relation with the tool, the loop further including pump means for the thermal transfer fluid; electrical heater means disposed in the control loop between the pump and tool and controllable in response to an energizing temperature control signal; heat exchanger means in the loop and receiving the thermal transfer fluid and the chilled refrigerant; proportional valve means coupled to receive the chilled refrigerant in the heat exchanger means for controlling the flow of chilled refrigerant in the heat exchanger means such as to maintain a selected temperature level in the below ambient temperature range in the thermal transfer fluid transferred to the tool; and means coupled to the heater means and providing a control signal for controlling the heater means to alternatively maintain a selected temperature level in the thermal transfer fluid that is above the ambient temperature level.