AUTOMOTIVE VEHICLE AUTOMATIC TEMPERATURE CONTROL SYSTEM

1433892 Fluid-pressure servomotor systems EATON CORP 27 March 1973 [28 March 1972] 14649/73 Heading G3P [Also in Division F4] In a heating system for a vehicle, a source 29, Fig. 1, of vacuum, such as the intake manifold, operates a motor 11 through a valve 23 responsive both to the temperature within the vehicle and to the temperature of air entering the vehicle. The motor operates a damper 15 mixing recirculated and fresh air as well as an electric switch 86, Fig. 2, controlling the speed of a motor 18 driving a blower 17. The valve 23 also supplies a motor 40 operating a damper 44 to adjust the distribution of air-flow within the vehicle and a damper 71 controlled by a selector 12 which may be rotated to direct heated air to the windows of the vehicle when necessary. Further dampers 59, 56 controlling the flow of fresh air and of recirculated air are operated so that one is closed when the other is opened by motors 50, 51 connected to the vacuum source by a solenoid operated valve 32 controlled by the switch 86, Fig. 2, and by a switch 150 responsive to the temperature of the engine coolant. During the heating phase, contacts 74, 75 on the switch 86 first energize the motor 18 direct from a battery 124 through a switch 122, contacts 81, 80 and contacts R and M in a blower switch. As the diaphragm 109, Fig. 3 in the motor displaces the contacts 74, 75 resistors 3R, 2R and 1 R are introduced one at a time into the motor circuit to reduce its speed. When the vehicle temperature has risen sufficiently for air conditioning to be required, the contacts 74, 75 engage a contact 82 and further contacts 80 to remove the resistors 3R, 2R and 1 R and increase the blower speed, until the last contact 80 is engaged and the blower motor is connected to the battery through a relay 120 to provide maximum cooling. In this final position of the switch 86, further contacts 78, 79 are engaged with contacts 83, 84 to energize the solenoid valve 32 operating the motors 50, 51, closing the damper 59 and opening the damper 56 to recirculate cooled air within the vehicle. These contacts also energize a solenoid 35 to lift a resilient ball valve (145), Fig. 5, (not shown) controlling a motor 60 and a further valve 63 which shuts off the flow of water to the heater. The solenoid in the valve 32 is also controlled by the switch 150 to open a contact arm 140 and prevent the blower motor from being energized before the engine warms up. The blower switch is manually operable to provid