Thumbwheel vacuum thermostat

Claim 2

An air temperature control system for an automobile having a passenger compartment comprising: a heater; means for conveying air through said heater and into said passenger compartment; a bypass around said heater; a movable air damper for proportioning the amount of air passing through said heater and through said bypass to produce a predetermined air temperature downstream from said heater affected by mixing warm air from said heater with cooler air from said bypass; a vacuum motor operably connected to said air damper for moving it in response to the strength of vacuum pressure therein which movement varies the portions of air passing through said heater and bypass to change the temperature of air downstream from said heater; a vacuum line connected to a source of raw vacuum pressure and said vacuum motor; regulator means for varying the strength of vacuum pressure in said vacuum line by bleeding a quantity of air into said vacuum line in response to the air temperature in said passenger compartment; said vacuum regulator means including an air bleed port between said passenger compartment and said vacuum line and a valve which controls the quantity of air admitted into said vacuum line; a first bimetal element operatively connected to said valve for opening and closing said valve in response to air temperature changes in said passenger compartment; a second bimetal element supporting said first bimetal element and responsive to air temperature changes in said passenger compartment to oppose the opening and closing movement of said first bimetal element; said second bimetal element being connected to a flexible hinge member in good heat transfer relation thereto for transferring heat between said second bimetal Element and said hinge member upon air temperature changes and therefore to cause said second bimetal element to respond less rapidly than said first bimetal element to air temperature changes; means connecting said first bimetal element and said valve for operating said valve in response to the combined movement of said bimetal elements; adjustment means including a manually rotatable eccentric pin operably connected to said hinge member for moving said bimetal elements relative to said valve which movement selectively varies the vacuum pressure in said vacuum line and changes the position of said air damper to affect a change in the air temperature in said passenger compartment whereby the heat transferred from said second bimetal element to said hinge member modifies the combined response of said bimetal elements to air temperature changes for positioning said air damper initially by movement of said first bimetal element and subsequently by the time delayed movement of said second bimetal element.

Claim 3

An air temperature control system for an automobile having a passenger compartment comprising: a heater; means for conveying air through said heater and into said passenger compartment; a bypass around said heater; a movable air damper for proportioning the amount of air passing through said heater and through said bypass to produce a predetermined air temperature downstream from said heater affected by mixing warm air from said heater with cooler air from said bypass; a vacuum motor operably connected to said air damper for moving it in response to the strength of vacuum pressure therein which movement varies the proportion of air passing through said heater and bypass to change the temperature of air downstream from said heater; a vacuum line connected to a source of raw vacuum pressure and said vacuum motor; regulator means for varying the strength of vacuum pressure in said vacuum line by bleeding a quantity of air into said vacuum line in response to the air temperature in said passenger compartment; said vacuum regulator including an air bleed port between atmosphere and said vacuum line and a valve which controls the quantity of air admitted into said vacuum line; a first bimetal element operably connected to said valve for opening and closing said valve in response to air temperature changes in said passenger compartment; a second bimetal element supporting said first bimetal element and responsive to air temperature changes in said passenger compartment to oppose the opening and closing movement of said first bimetal element; a flexible hinge member supporting said second bimetal element; means connecting said first bimetal element and said valve for operating said valve in response to the combined movement of said bimetal elements; adjustment means including a manually rotatable eccentric pin contacting said hinge member for moving said bimetal elements relative to said valve which movement selectively varies the vacuum pressure in said vacuum line and thus changes the position of said air damper for affecting a change in said predetermined air temperature in said passenger compartment; said hinge member being connected in good heat transfer relation to said second bimetal element for transferring heat therefrom upon air temperature changes thereby delaying the response of said second bimetal element to air temperature changes; said hinge member shielding said second bimetal element from the flow of air through said vacuum regulator therefore further delaying the response of said second bimetal element to air temperature changes whereby said air damper is initially positioned upon a change in air temperature by movement of said first bimetal element and subsequently by the time delayed movement of said second bimetal element; vacuum port means in said regulator adapted to be connected to a source of raw vacuum pressure for continually drawing air from said passenger compartment through said regulator and over said bimetal elements.

Claim 4

An air temperature control system for an automobile having a passenger compartment comprising: a heater; means for conveying air through said heater and into said passenger compartment; a bypass around said heater; a movable air damper for proportioning the amount of air passing through said heater and through said bypass to produce a predetermined air temperature downstream from said heater affected by mixing warm air from said heater with cooler air from said bypass; a vacuum motor operably connected to said air damper for moving it in response to the strength of vacuum pressure therein which movement varies the proportion of air passing through said heater and bypass to change the temperature of air downstream from said heater; a vacuum line connected to a source of raw vacuum pressure and said vacuum motor; regulator means for varying the strength of vacuum pressure in said vacuum line by bleeding a quantity of air into said vacuum line in response to the air temperature in said passenger compartment; said vacuum regulator including an air bleed port between atmosphere and said vacuum line and a valve which controls the quantity of air admitted into said vacuum line; a first bimetal element operably connected to said valve for opening and closing said valve in response to air temperature changes in said passenger compartment; a second bimetal element supporting said first bimetal element and responsive to air temperature changes in said passenger compartment to oppose the opening and closing movement of said first bimetal element; a flexible hinge member supporting said second bimetal element; means connecting said first bimetal element and said valve for operating said valve in response to the combined movement of said bimetal elements; adjustment means including a manually rotatable eccentric pin contacting said hinge member for moving said bimetal elements relative to said valve which movement selectively varies the vacuum pressure in said vacuum line and thus changes the position of said air damper for affecting a change in said predetermined air temperature in said passenger compartment; said hinge member being connected in good heat transfer relation to said second bimetal element for transferring heat therefrom upon air temperature changes thereby delaying the response of said second bimetal element to air temperature changes; said hinge member shielding said second bimetal element from the flow of air through said vacuum regulator therefore further delaying the response of said second bimetal element to air temperature changes whereby said air damper is initially positioned upon a change in air temperature by movement of said first bimetal element and subsequently by the time delayed movement of said second bimetal element; vacuum port means in said regulator adapted to be connected to a source of raw vacuum pressure for continually drawing air from said passenger compartment through said regulator and over said bimetal elements.