US3876138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Duct pressure actuated variable volume device
Assignee: TEMPMASTER CORP
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Filing: 1973-12-06
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Granted: 1975-04-08
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Expires: 1993-12-06
Abstract
Abstract A self contained unit for controlling the volume of airflow through an air duct ventilation system has an inflatable bag which is operated by the pressure of airflow in the duct to variably position a normally open damper and control airflow through the duct. Inflation of the bag pivots an overlying plate and connecting linkage to reliably position the damper. A pneumatic thermostat controls exhaust flow from the bag to adjust pressure therein. An aspirating nozzle in the thermostat is fed with relatively high velocity airflow from the duct, and by aspiration induces a flow of ambient air through the thermostat and across a bimetallic, thermally responsive control element thereof which moves in response to changes in temperature to vary pressure in the bag.
Inventors
- 👤 Jr Frank J Dean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:49
CPC Classifications
F; F24; F24F; F24F11/00; F24F11/70; F24F11/72; F24F11/74; F24F11/76; F24F13/00; F24F13/08; F24F13/082; F24F2013/087
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
207 words
In an air duct ventilation system having a pressure responsive mechanism for varying the volume of airflow through the duct of the system, means for controlling pressure in said mechanism, comprising: means defining a passage for exhausting air from said mechanism; a conduit receiving air from said duct and discharging the air to an exhaust port, said conduit connected with said passage and bypassing same at an angle to induce airflow from said mechanism by aspiration in response to airflow through said conduit; a housing having an inlet and an outlet for accommodating flow of ambient air therethrough, said housing containing said exhaust port; thermally responsive valve means mounted inside said housing intermediate said inlet and outlet thereof and movable toward and away from said exhaust port to vary the exhaust of air from said mechanism to thereby control pressure therein, said valve means being movable in response to a change in temperature in the ambient air; and means connected with said housing for inducing by aspiration a flow of ambient air through said inlet across said valve means and out said outlet whereby said valve means is positioned and volume of airflow through said duct is varied in relation to the temperature of the ambient air.
Claim 2
Dependent Claim
207 words
In an air duct ventilation system having a pressure responsive mechanism for varying the volume of airflow through the duct of the system, means for controlling pressure in said mechanism, comprising: means defining a passage for exhausting air from said mechanism; a conduit receiving air from said duct and discharging the air to an exhaust port, said conduit connected with said passage and bypassing same at an angle to induce airflow from said mechanism by aspiration in response to airflow through said conduit; a housing having an inlet and an outlet for accommodating flow of ambient air therethrough, said housing containing said exhaust port; thermally responsive valve means mounted inside said housing intermediate said inlet and outlet thereof and movable toward and away from said exhaust port to vary the exhaust of air from said mechanism to thereby control pressure therein, said valve means being movable in response to a change in temperature in the ambient air; and means connected with said housing for inducing by aspiration a flow of ambient air through said inlet across said valve means and out said outlet whereby said valve means is positioned and volume of airflow through said duct is varied in relation to the temperature of the ambient air.
Claim 3
Dependent Claim
62 words
Pressure control means as set forth in claim 1, wherein said inducing means includes a conduit having an open end disposed in said duct and opening in said housing in direct alignment with said outlet thereof, whereby airflow from said duct through said conduit and out said outlet of the housing induces by aspiration said flow of ambient air inside the housing.
Claim 4
Dependent Claim
71 words
Pressure control means as set forth in claim 2, wherein said valve means includes a bimetallic strip having one end secured in cantilevered arrangement to said housing, and an opposite end located in overlying relationship to said exhaust port, said strip being deflected by a change in ambient air temperature to move said opposite end of the strip relative to said exhaust port and variable meter flow of exhaust air therethrough.
Claim 5
Dependent Claim
67 words
Pressure control means as set forth in claim 3, wherein said inlet in the housing is an elongated slot in a bottom wall of the housing, said outlet being of generally circular cross-sectional area and of greater area than said conduit, said bimetallic strip being generally horizontally arranged in said housing and being deflected in a vertical direction in response to a change in ambient air temperature.
Claim 6
Dependent Claim
50 words
Pressure control means as set forth in claim 3, wherein is included a manually shiftable calibration lever mounted to said housing in engagement with said bimetallic strip, said lever being accessible for manual shifting to position said strip relative to said exhaust port to vary the pressure within said mechanism.
Claim 7
Dependent Claim
63 words
Pressure control means as set forth in claim 5, wherein said lever includes a circular cam surface in engagement with said bimetallic strip, said lever being pivotally secured to said housing at a point offset from the geometric center of said cam surface whereby manual rotation of said lever causes said cam surface to shift said bimetallic strip relative to said exhaust port.
Claim 8
Dependent Claim
188 words
Means for controlling the volume of airflow through an air duct ventilation system, comprising: a damper plate in the air duct of the system movable to variably restrict airflow through said duct; pneumatically operated actuator means operably coupled to said plate to move same and vary the volume of airflow through said duct in proportion to said pressure in the acutator means; a conduit having one end is disposed in said duct for sensing pressure therewithin said conducting airflow from said duct in relation to said sensed pressure, said conduit having an opposite end terminating in an exhaust port; an aspirating tee interconnecting said conduit intermediately thereof with said actuator means at right angle, whereby airflow through said conduit and across said aspirating tee to said exhaust port induces exhaust flow of air out of said acutator means to said exhaust port; and thermally responsive valve means shiftable toward and away from said exhaust port to variably restrict said exhaust flow of air from said actuator means, said valve means being exposed to ambient air and responsive to a change in temperature thereof to control said exhaust flow.
Claim 9
Dependent Claim
188 words
Means for controlling the volume of airflow through an air duct ventilation system, comprising: a damper plate in the air duct of the system movable to variably restrict airflow through said duct; pneumatically operated actuator means operably coupled to said plate to move same and vary the volume of airflow through said duct in proportion to said pressure in the acutator means; a conduit having one end is disposed in said duct for sensing pressure therewithin said conducting airflow from said duct in relation to said sensed pressure, said conduit having an opposite end terminating in an exhaust port; an aspirating tee interconnecting said conduit intermediately thereof with said actuator means at right angle, whereby airflow through said conduit and across said aspirating tee to said exhaust port induces exhaust flow of air out of said acutator means to said exhaust port; and thermally responsive valve means shiftable toward and away from said exhaust port to variably restrict said exhaust flow of air from said actuator means, said valve means being exposed to ambient air and responsive to a change in temperature thereof to control said exhaust flow.
Claim 10
Dependent Claim
61 words
Control means as set forth in claim 7, wherein is included an adjustable restrictor interposed in said downstream section of the conduit for establishing the maximum rate of said exhaust flow from the actuator means to thereby establish the maximum volume of airflow through said duct when said valve means is in a position allowing maximum flow through said exhaust port.
Claim 11
Dependent Claim
66 words
Control means as set forth in claim 8, wherein is included a manually adjustable bleed port in said downstream section of the conduit open to ambient air for establishing a minimum rate of said exhaust flow from said actuator means to thereby establish the minimum volume of airflow through said duct when said valve means is in a position allowing minimum flow through said exhaust port.
Claim 12
Dependent Claim
78 words
Control means as set forth in claim 7, wherein is included means extending generally transversely to the direction of airflow in said duct and pivotally mounting said damper plate to said duct, said pivot means being secured to said damper plate at a position offset from the center of said plate whereby the pressure of airflow in said duct acting on said damper plate urges the latter toward a position permitting maximum volume of airflow through said duct.
Claim 13
Dependent Claim
91 words
Control means as set forth in claim 7, wherein said actuator means includes a pneumatically inflatable member supplied with pressurized air from said aspirating tee, a rigid plate over-lying said member and having one end pivotally attached to said duct whereby inflation of the member rotates said rigid plate in proportion to the pressure in said member, said rigid linkage having opposite ends connected to said damper plate and said rigid plate whereby rotation of said rigid plate shifts said damper plate proportionately in relation to said pressure in the member.
Claim 14
Dependent Claim
82 words
Control means as set forth in claim 7, wherein is included a housing enclosing said valve means and said exhaust port, and having an inlet and outlet for accommodating flow of ambient air therethrough, and means connected with said housing for inducing by aspiration a flow of ambient air through said housing and across said valve means whereby said valve means is positioned and the volume of airflow through said duct is varied in relation to the temperature of the ambient air.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |