Thermally powered diffuser

• US 6,176,435 B1
• Filed: 06/25/1999
• Issued: 01/23/2001
• Est. Priority Date: 06/26/1998
• Status: Expired due to Term

• Current Assignee: Metal Industries Incorporated (J T Walker Industries Incorporated)
• Original Assignee: Marty Nielsen
• Inventors: Nielsen, Marty
• Primary Examiner(s): Doerrler, William
• Assistant Examiner(s): NORMAN, MARC E
• Application Number:
  US09/339,887
• Time in Patent Office: 578 Days
• Field of Search: 236/49.5, 236/49.3, 236/1.C, 236/91.E, 236/99.E, 236/DIG.19, 454/258
• US Class Current: 236/49.5
• CPC Class Codes: F24F 11/76 by means responsive to temperature, e.g. bimetal springs
• CPC Class Codes: F24F 13/16 built up of parallelly-movable plates
• CPC Class Codes: Y10S 236/19 Ventilated thermostat

Abstract

A thermally powered variable air volume diffuser is provided, comprising a diffuser housing and a thermally powered actuator assembly mounted therein which varies the size of a supply air discharge opening. The actuator assembly comprises four thermal actuators and means operatively connecting the thermal actuators to a flow control disc defining the discharge opening. The volume of air supplied to a room is varied in response to changes in air supply temperature and room temperature. In the heating cycle, the first thermal actuator lowers the flow control disc, causing increased supply air output. Heated air from the air supply duct causes the second thermal actuator to engage the third thermal actuator. As room temperature rises, the third thermal actuator pushes the second thermal actuator, raising the flow control disc and reducing supply air output. In the cooling mode the supply air is provided below a set temperature so that the first and second thermal actuators do not respond to actuate flow control disc movement, and only the fourth thermal actuator varies the supply air. As room air temperature rises, the fourth thermal actuator lowers the flow control disc. As the room cools, the fourth thermal actuator causes the opposite effect.

Claims

1. A thermally powered variable air volume diffuser that regulates air volume delivery in response to both air supply and room air temperature changes comprising:

a diffuser housing for connection to an air supply duct and having an supply air inlet and a diffused air outlet;

air flow outlet control means for varying the volume of air discharged from said diffused air outlet, said air flow outlet control means positioned relative to said diffuser housing so as to define an air discharge opening;

a first thermal actuator positioned to be exposed primarily to supply air and thermoactively responsive only when warm supply air heats said first thermal actuator above a preselected response threshold temperature, said first thermal actuator operatively connected to said air flow outlet control means so as to increase the size of the discharge opening as the temperature of said first thermal actuator rises above its response threshold temperature;

a second thermal actuator positioned to be exposed primarily to supply air and thermoactively responsive only when warm supply air heats said second thermal actuator to a temperature above a preselected response threshold temperature higher than the temperature at which said first thermal actuator responds, said second thermal actuator operatively connected to said air flow outlet control means so as to decrease the size of the discharge opening as the temperature of said second thermal actuator increases above its response threshold temperature;

a third thermal actuator positioned to be exposed primarily to room air and thermoactively responsive only when the temperature of said third thermal actuator rises above a preselected response threshold temperature, said third thermal actuator operatively connected to said air flow outlet control means so as to decrease the size of the air discharge opening as the temperature of said third thermal actuator rises above the preselected response threshold temperature of said third thermal actuator;

a fourth thermal actuator positioned to be exposed primarily to room air and thermoactively responsive only when heated above a preselected response threshold temperature when cool supply air has cooled said first, second, and third thermal actuators below their respective response temperature thresholds, said fourth thermal actuator operatively connected to said air flow outlet control means so as to increase the size of the discharge opening when heated above its response temperature threshold.

2. The thermally powered variable air volume diffuser of claim 1 wherein said air flow outlet control means is a flow control disc positioned relative to the underside of said diffuser housing so as to define an air discharge opening, said flow control disc having a circumferential brim portion and an interior conical damper portion.

3. The thermally powered variable air volume diffuser of claim 1, further comprising a thermal actuator assembly mounted within said diffuser housing and having means for mounting said first thermal actuator is mounted, means for mounting said second thermal actuator, means for mounting said third thermal actuator, and means for mounting said fourth thermal actuator.

4. The thermally powered variable air volume diffuser of claim 3 further including a chassis having a horizontal base portion, a first vertical section and a second vertical section, and wherein said means for mounting said first thermal actuator is a first bracket affixed to said chassis, and wherein said means for mounting said second thermal actuator is a second bracket affixed to said chassis, and wherein said means for mounting said third thermal actuator is a third bracket affixed to said chassis, and wherein said means for mounting said fourth thermal actuator is a fourth bracket affixed to said chassis.

5. The thermally powered variable air volume diffuser of claim 4 wherein said first thermal actuator has a first cap having a hollow cavity containing thermoactive material, and further has a first integral hollow threaded stem extending from said first cap and threadably mounted to said first bracket, and a first movable shaft surrounded by said first cylindrical stem;

and wherein said second thermal actuator has a second cap having a hollow cavity containing thermoactive material, a second integral threaded stem threadably mounted to said second bracket, and a second movable shaft housed within said second threaded stem; and

wherein said third thermal actuator has a third cap having a hollow cavity containing thermoactive material, a third integral threaded stem extending from said cap, a first isolator bushing into which said third threaded stem is threadably mounted, a first hollow cylindrical post extending upwardly from said first isolator bushing, and a third movable shaft the distal end of which extends beyond the end of said first hollow cylindrical post; and

wherein said fourth thermal actuator has a fourth cap having a hollow cavity containing thermoactive material, a fourth integral threaded stem extending from said cap, a second isolator bushing into which said fourth threaded stem is threadably mounted, a second hollow cylindrical post extending upwardly from said second isolator bushing, and a fourth movable shaft the distal end of which extends beyond the end of said second hollow cylindrical post post.

6. The thermally powered variable air volume diffuser of claim 4 wherein said first thermal actuator has a first cap having a hollow cavity containing thermoactive material, and further has a first integral hollow threaded stem extending from said first cap and threadably mounted to said first bracket, and a first movable shaft surrounded by said first cylindrical stem;

and wherein said second thermal actuator is a metal memory actuator mounted to said second bracket, said second thermal actuator actuator having a bimetalic helical coil spring movably connected to a second movable shaft; and

wherein said third thermal actuator has a third cap having a hollow cavity containing thermoactive material, a third integral threaded stem extending from said cap, a first isolator bushing into which said third threaded stem is threadably mounted, a first hollow cylindrical post extending upwardly from said first isolator bushing, and a third movable shaft the distal end of which extends beyond the end of said first hollow cylindrical post; and

wherein said fourth thermal actuator has a fourth cap having a hollow cavity containing thermoactive material, a fourth integral threaded stem extending from said cap, a second isolator bushing into which said fourth threaded stem is threadably mounted, a second hollow cylindrical post extending upwardly from said second isolator bushing, and a fourth movable shaft the distal end of which extends beyond the end of said second hollow cylindrical post post.

7. The thermally powered variable air volume diffuser of claim 6 wherein said helical coil spring of said second thermal actuator is a nickel-titanium alloy.

8. The thermally powered variable air volume diffuser of claim 5 wherein said fourth cap includes circumferential outwardly projecting radial fins to increase the thermal sensitivity and responsiveness of said fourth actuator.

9. The thermally powered variable air volume diffuser of claim 3 wherein said actuator assembly is mounted within said supply air inlet and further comprises:

a chassis with a horizontal base portion, a first vertical section, and a second vertical section, each of said first and second vertical sections having a transverse aperture;

a transverse axle rotatably mounted through the transverse apertures of said first and second vertical sections and extending outwardly from each of said first and second vertical sections;

a U-arm having apertures at each of its arms and pivotally mounted on said transverse axle, at least one of said arms cantilevering beyond said transverse axle to form said second bracket for mounting said second thermal actuator;

a lever assembly pivotally affixed to said transverse axle at one end and to said flow controller disc at the other end;

a first radial tab affixed to said transverse axle;

a first angular force means for imparting an angular force to the transverse axle;

a second radial tab member affixed to the approximate middle of said transverse axle and extending outwardly therefrom;

a third radial tab member affixed to the approximate middle of said transverse axle and extending outwardly therefrom;

a second angular force means interposed between said second radial tab member and said U-arm so as to impart an angular force to said second radial tab member and an opposing angular force to said U-arm.

10. The thermally powered variable air volume diffuser of claim 9 wherein said first angular force means is a helical extension spring.

11. The thermally powered variable air volume diffuser of claim 9 wherein said second angular force means is a right hand torsion spring biased against both said U-arm and said second radial tab member.

12. The thermally powered variable air volume diffuser of claim 9 wherein said second angular force means is a right hand torsion spring.