Constant temperature control for a vehicle compartment heater or heater-air-conditioner

Claim 2

A temperature control system, comprising: duct means for delivering conditioning air to a region to be temperature conditioned by said air; conduit means for delivering a hot liquid in a heat exchanging relation with the conditioning air in said duct means; and means for maintaining the temperature of the conditioning air at a selected value, comprising: a normally open off-on valve in said conduit means, said off-on valve including a valve orifice, a valve plug moveable into the valve orifice for closing the valve, and out from the valve orifice for opening the valve, with spring means normally biasing the valve plug into an open position, and air cylinder means operable in opposition to the spring, for moving the valve plug into a closed position; a temperature level selector means for the region to be temperature conditioned; temperature sensing means for sensing the temperature of the conditioning air; and control means responsive to a difference between the selected temperature level and the sensed temperature for moving the off-on valve into a fully closed position when the temperature of the conditioning air is higher than the selected temperature level, and moving the off-on valve into a fully open position when the selected temperature level is higher than the temperature of the conditioning air, said control means comprising a source of air under pressure, conduit means leading from such source to the air cylinder means, and a three-way valve in said conduit means, having a first position in which the air cylinder is vented to the atmosphere and flow from the source of compressed air to the air cylinder is blocked, and a second position in which passage to the atmosphere is blocked and flow is from the source of compressed air into the air cylinder, and means normally biasing the three-way valve into said first position.

Claim 3

A temperature control system for a passenger compartment of a motor vehicle of a type having a water cooled engine, comprising: duct means for delivering conditioning air into the passenger compartment of the vehicle; conduit means for delivering hot water from the water cooled engine into a heat exchanging relation with the conditioning air in said duct means; and means for maintaining the temperature of the conditioning air at a selected value, comprising: a normally open off-on valve in said conduit means said off-on valve including a valve orifice, a valve plug moveable into the valve orifice for closing the valve, and out from the valve orifice for opening the valve, with spring means normally biasing the valve plug into an open position, and air cylinder means operable in opposition to the spring, for moving the valve plug into a closed position; a temperature level selector means located in the passenger compartment of the vehicle; temperature sensing means for sensing the temperature of the conditioning air; and control means responsive to a difference between the selected temperature level and the sensed temperature for moving the off-on valve to a fully closed position when the temperature of the conditioning air is higher than the selected temperature level, and moving the off-on valve to a fully open position when the selected temperature level is higher than the temperature of the conditioning air, said control means comprising a source of air under pressure, conduit means leading from such source to the air cylinder means, and a three-way valve in said conduit means, having a first position in which the air cylinder is vented to the atmosphere and flow from the source of compressed air to the air cylinder is blocked, and a second position in which passage to the atmosphere is blocked and flow is from the source of compressed air into the air cylinder, and means normally biasing the three-way valve into said first position.

Claim 4

A temperature control system for a passenger compartment of a motor vehicle of a type having a water cooled engine, comprising: duct means for delivering conditioning air into the passenger compartment of the vehicle; conduit means for delivering hot water from the water cooled engine into a heat exchanging relation with the conditioning air in said duct means; and means for maintaining the temperature of the conditioning air at a selected value, comprising: a normally open off-on valve in said conduit means said off-on valve including a valve orifice, a valve plug moveable into the valve orifice for closing the valve, and out from the valve orifice for opening the valve, with spring means normally biasing the valve plug into an open position, and air cylinder means operable in opposition to the spring, for moving the valve plug into a closed position; a temperature level selector means located in the passenger compartment of the vehicle; temperature sensing means for sensing the temperature of the conditioning air; and control means responsive to a difference between the selected temperature level and the sensed temperature for moving the off-on valve to a fully closed position when the temperature of the conditioning air is higher than the selected temperature level, and moving the off-on valve to a fully open position when the selected temperature level is higher than the temperature of the conditioning air, said control means comprising a source of air under pressure, conduit means leading from such source to the air cylinder means, and a three-way valve in said conduit means, having a first position in which the air cylinder is vented to the atmosphere and flow from the source of compressed air to the air cylinder is blocked, and a second position in which passage to the atmosphere is blocked and flow is from the source of compressed air into the air cylinder, and means normally biasing the three-way valve into said first position.

Claim 5

A temperature control system in accordance with claim 1, comprising a spring for normally biasing the three-way valve into said first position.

Claim 6

A temperature control system in accordance with claim 1, comprising solenoid means for shifting the three-way valve from its first position to its second position.

Claim 7

A temperature control system in accordance with claim 2, comprising a spring for normally biasing the three-way valve into said first position.

Claim 8

A temperature control system in accordance with claim 2, comprising solenoid means for shifting the three-way valve from its first position to its second position.

Claim 9

A temperature control system according to claim 6, wherein the temperature level selector means includes variable resistor means for changing the value of a voltage delivered to a junction in an electronic control circuit and the temperature sensing means is a thermister connected to deliver a voltage signal to the same junction, and wherein the means responsive to a difference between the selected temperature level and the sensed temperature comprises an integrated circuit which compares the summed voltage at the junction with a base voltage, and transistor means connected to the integrated circuit, operable by a signal from the integrated circuit to open and send a control voltage to the electrical solenoid when the sensed temperature level is above the selected temperature level, and to close and disconnect the control voltage from the solenoid when the sensed temperature level is below the selected temperature level.