CA1107560A - Motorized air damper having 360 continuous rotation with two way switch control - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A motorized damper for a forced air home heating system, wherein a damper plate is mounted in a housing for 360 degree continuous rotation in one direction, to successively open and close the damper.
An electric motor rotates the damper and is connected through a first two-way switch actuated by the damper plate to a wall mounted second two-way switch and thence to a power source. When an occupier enters the room and operates the wall two-way switch, the motor rotates the damper plate from closed to open position, at which time the damper plate actuates the first two-way switch to de-energize the motor. When the occupier leaves the room, he again operates the wall switch to turn on the motor and rotate the damper plate to its closed position, whereupon the damper plate actuates the first two-way switch again to shut off the motor. A number of dampers can be centrally controlled by a central processor and an override switch may be used so that when an occupant enters a room, all of the home dampers except that in such room will close for a short time to direct the entire furnace output to that room to rapidly heat the room.

Description

1~D756~) This invention relates to a motorized damper for a forced air system, typically a forced system of the kind found in homes.
Homes having warm air heating systems normally have warm air ducts which lead to the various rooms in the home, and dampers which are located at the ends of the ducts to control the flow of warm air in the room. The dampers presently used are manually operated, usually by a thumbwheel or other control located in the damper. A manual control is usually stiff and difficult to operate and additionally is located at floor level where it is difficult to reach. In some cases the damper may be located beneath or behind furniture, where it is impossible to reach. For these reasons, the manually operated dampers found in homes are rarely if ever operated, and warm air is allowed to flow into each room in the home regardless of whether the room is occupied.
The failure to use manually operated dampers in homes results in a substantial wastage of fuel. If rooms which are not in use were allowed to remain unheated, except for heat flowing from the remainer of the home, then such rooms would typically assume a temperature of 10 to 15~F less than the remainder of the home which is heated. If substantial portions of the home were allowed to remain unheated while they were not in use, then very large savings in fuel could be achieved.
Accordingly, the present invention provides a motor-ized damper which is extremely simple but unique in design, 11~756~

inexpensive to construct, and which can be operatedin a very simple manner to shut off the flow of warm air to a room or to admit warm air to the room, as desired. In one embodiment the invention provides a forced air damper comprising a housing having a passage for flow of air therethrough, a damper plate, and axle means in the housing mounting the damper plate in the passage for continuous rotation in one direction through 360~, so that the damper plate in one position will close the housing to flow of air therethrough and in a second position rotated through an angle from a first position will open the housing to flow of air therethrough. An electric motor is connected to the axle means for rotating the damper plate in the required direction when the motor is energized, and two-way switch means are provided having three contacts, one contact connected to the motor and two contacts adapted to be connected to a second two-way switch. The two-way switch means includes actuator means operable for connecting the motor lead alternately sequentially to one and then the other of the switch contacts, so that the switch has a first switching ~ condition when the motor lead is connected to one contact - and a second switching condition when the motor lead is connected to the second switch contact. The contacts of the switch means are mounted on the housing and the actuator means is mounted on the damper plate. The switch means and damper plate are located so that rotation of the damper plate from its first to its second position will operate the actuator means to place the switch means in one switch condition and for rotation of the damper plate 1~756~) from its second to its first position to operate the actuator means to place the switch in its second switch condition~ By this arrangement a second two-way switch, which may be located at the entrance to a room in which the damper is located, can be operated when the occupier enters the room, to cause the damper plate to rotate to its open position. When the damper plate reaches its open .
position the electric motor will shut off, due to the two-way switch means on the damper, and heat will then enter the room. When the occupant leaves the room, he may operate the same switch at the door again (since it is connected in a two-way switch arrangement with the switch means on the damper), and the damper plate will then rotate again until it is closed, at which time the two-way switch means on the damper will again shut off the electric motor.
If desired, the room switch may be a thermo-stat, so that control of the heat in the room is automatic, simply by setting the thermostat.
Alternatively, or in addition, a central processing unit may be provided to operate allo f the dampers according to a predetermined program, and an override switch may be provided so that when an occupant enters a room and operates a switch to open its damper, he may also operate the over-ride switch to close the dampers in all of the other rooms in the house for a predetermined interval, for example five minutes. During this time all of the warm air output from the furnace will be forced into the room which the occupant has entered, thereby rapidly heating that room to the desired temperature. The other rooms will cool , 1~756~

only slightly during this relatively short interval.
After the predetermined time interval has elapsed, the system resumes its normal condition.
Further objects and advantages of the invention will appear from the following description, taken together with the accompanying drawings, in which:
Fig. 1 is a perspective view, partly cut away, showing a damper according to the invention;
Fig. 2 is a top plan view of the damper of Fig. l;
Fig. 3 is an end view of the damper plate of the Fig. 1 damper;
Fig. 4 is a schematic of a circuit for the damper of Fig. l;
Fig. 5 is a diagrammatic view of a room in which a damper according to the invention is installed;

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Fig. 6 is a schematic of a slightly modified circuit for the damper of Fig. l;
Fig. 7 is a perspective view of a portion of the damper of Fig. 1 and showing ratchet means in position to prevent reversal of the direction of movement of the damper plate;
Fig. 8 is a perspective view showing a modified device for preventing reversal of the damper plate direction of rotation;
Fig. 9 is a perspective view showing a modified switch for the damper of Fig. l;
Fig. 10 is a perspective view showing a further modified switch for the damper of Fig. l; and Fig. 11 is a schematic view of a central , . . . . . .
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processor arranged to control a multitude of dampers according to the invention, and with an override switch for each damper.
Reference is first made to Fig. 1, which shows a damper generally indicated at 10. The damper 10 includes a housing 12 having two elongated sides 14, 16 and two ends 18, 20 which are arranged to form a rectangular box having a through opening 22 therein. --Mounted in the opening 22 is a rectangular damper plate 24.
The damper plate 24 carries a pair of stub axles 25, 26, one at each end thereof. The axle 25 is journalled in a hole (not shown) in a channel-shaped piece of sheet metal 28 welded to the end plate 18. The - axle 26 extends through a hole in the end plate 20 and is connected to an electric motor 30 (Fig. 2).
The electric motor 30 (which includes built-in gears, .~ not shown, to provide an appropriate low output speed) is arranged to rotate the damper plate 24 in the direction of arrow A, Fig. 1.
As will be apparent from the drawings, the damper plate 24 substantially closes the opening 22 when it is in a horizontal position, and presents a minimum obstruction to air flow when it is in a vertical position (in which case the damper is termed "open").
Two-way switch means are provided to control the operation of motor 30 in conjunction with a second two-way switch mounted near the room entrance, so that the damper plate can be stopped simply and automatically in either its closed or its open positions. The two-- 6 - `
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11~756~) way switch means of the damper includes a single pole double throw microswitch 32 having a pair of fixed contacts 34, 36 (Figs. 2 and 4) and a movable contact 38. The movable contact 38 is operable by a lever arm 40 which is hinged at one end to the microswitch and which extends outwardly horizontally into the path of the damper plate 24. Whenever the lever arm 40 is pushed toward the microswitch body, it operates a conventional plunger 41 (which is spring biased outwardly by a spring not shown) to move the contact 38 alternately sequen-tially from contact 34 to contact 36 and then back again, as is conventional for a single pole double throw microswitch.
The switch means of the damper also includes a pair of actuator plates 42, 44 mounted at the end of the damper plate 24 adjacent the microswitch 32. The actuator plates 42, 44 are located in a common vertical ; plane, one at each side of the damper plate 24, and each spaced slightly sideways of the axle 26. Each actuator plate 42, 44 has generally the form of a quarter circle and each extends in an opposite direction from the other so that when the damper plate 24 for example is horizontal, actuator plate 42 extends upwardly and actuator plate 44 extends downwardly. Each actuator plate has an outer periphery 46 of circular configuration, and an inner edge 48 which extends at right angles from the damper plate 24 to meet the outer periphery 46.
As shown in Figs. 4 and 6, the contacts 34, 36 of the damper are connected to contacts 50, 52 of another two-way switch 54 having a movable contact 56.

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Contact 56 is connected to one side of a power source 58 (typically 110 volts), the other side of the power source being connected through lead 60 to one side of the motor 30.
The other side of the motor 30 is connected to movable contact 38. Switch 54 is typically located beside the door 62 (Fig. 5) of a room 64 in which the damper 10 is located.
The operation of the damper 10 is as follows.
Assume that the damper plate 24 is in a horizontal position, in which case the damper is closed. In this condition neither actuator plate 44 nor actuator plate 42 is contacting the lever arm 40 and the condition of the two-way switch means of the damper will be as shown in Fig. 4. In this condition no complete circuit is made from power source 58 through the two two-way switches to motor 30 and the motor remains off.
When an occupant enters the room, he operates two-way switch 54 to move the contact 56 to connect to contact 50. This energizes the motor 30 and the damper ~ 20 rotates in the direction of arrow A. As the damper - rotates, the edge 66 of actuator plate 44 moves against and depresses the lever arm 40, depressing the plunger -41 of the microswitch 32 and thereby moving the contact ~; 38 to connect to contact 36. This opens the motor circuit and the motor 30 stops with the damper plate 24 in its full open position. The actuator plate 44 holds the lever arm 40 depressed even after the edge 66 passes the end of the lever arm 40.
When the occupant leaves the room 64, he again operates the switch 54, moving contact 56 to ~, .

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connect to contact 52. This re-energizes the motor 30 and the motor operates, turning the damper plate 24 until the damper plate has reached its horizontal position. At this time the edge 48 of actuator plate 44 moves off the lever arm 40, allowing the plunger 41 to move outwardly under the spring bias of the micro-switches 32 . This moves movable contact 38 back to contact 34, opening the motor circuit and stopping the ~ motor 30 with the damper in its closed posltion.
-~ 10 When the process is repeated by an occupant re-entering the room and reoperating switch 54, and causing the damper plate to rotate again, actuator plate 42 will operate the lever arm 40, operating the microswitch 32 to open the motor circuit to hold the damper plate in open position. Then, when the occupant leaves the room and reoperates the switch 54, the motor 30 rotates the damper plate 24 towards its closed posiiion, at which time actuator plate 42 will release the lever arm 40 to stop the motor with the damper 20 plate 24 in its closed position. -; In summary, it will be seen that the damper 10 has two closed positions and two open positions, each open position being located between a pair of ~ -closed positions, and the various positions being reached ` by continuous rotation of the damper plate 24 in one direction only. The damper includes two-way switch means connected to a two-way switch in the room in which the ; damper is located, so that whenever the room two-way switch 54 is operated, the damper will change its position, either from open to closed or from closed .~ .
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to open. Because the rotation is continuous in one direction, the damper 10 may be made simply and inexpen-sively and without high precision being required. If desired, only one actuator plate 42 or 44 could be provided, but two are preferred.
If desired, a thermostatic switch 67 (Fig. 6) - may be used in place of the two-way switch 54. The switch 67 is a single pole double throw switch identical to switch 54, except that it is thermostatically operated by a conventional temperature sensor 68 which controls a conventional thermostat actuator 69. Whenever the temperature sensor senses a change in temperature past its high or low settin~, it operates actuator 69 which operates in the same manner as microswitch plunger 41.
Actuator 69 then moves contact 56' to change its connection, either from contact 50' to contact 52' or vice versa. The switches 67 and 32 are initially set so that when the temperature sensor moves past its high limit, the damper will move from its open to its closed position. The thermostatic switch 67 may be located near the door of a room in the same position as switch 54 so that it can readily be set by an occupant.
When a very inexpensive electric motor 30 is used, for example a shaded pole motor, the motor 30 may sometimes have a tendency to rotate slightly in a direction reversed - to that indicated by arrow A, before it resumes its correct direction of rotation. This is undesirable when the damper is initially open, since the edge 66 of the actuator plate 42 maymove off the lever arm 40, shutting off the unit. Therefore, if desired, ratchet means indicated in Fig. 7 may be provided to ensure that the damper plate 24 can rotate for example from its open position only in one ~1~75~

direction. The ratchet means of Fig. 7 consists of two metal strips 70, 72 secured to a side flange 74 at the top of the damper 10 and extending horizontally outwardly towards the damper plate 24. The metal strip 70 lies in a vertical plane and has a sloping end 76 which engages the top of the damper plate 24 when the damper is in a vertical position, and prevents the direction of rotation of the damper plate from being reversed. The metal strip 72 has a series of saw teeth 78 which engage the upper edge of the damper plate and add further assurance that the direction of rotation of the damper plate will not be reversed.
Alternatively, and as shown in Fig. 8, the axle 25 may terminate in a small fine tooth ratchet wheel 80 located between the metal plate 28 and the end wall 18. A short arm 82 secured to plate 28 engages the teeth of wheel 80 and ensures that the direction of rotation of the damper plate 24 cannot reverse.
- Reference is next made to Fig. 9, which shows an alternative switch means for the damper 10. In the ~-Fig. 9 embodiment, the damper plate 24 is provided with a circular end plate 84 having a switch contact plate ; 86 mounted thereon. Switch contact plate 86 includes a central annular contact ring 88, a pair of outer annular contact segments 90, 92 each extending around an arc of 90 and each spaced 90 from the other, and a pair of inner annular contact segments 94, 96 each also extending around an arc of 90 and spaced 90 from each other. Contact segment 94 is located between contact segments 90, 92 and -~ contact segment 96 is located opposite segment 94 and is also located between segments 90, 92. Contact segments 88, 90, 92, 94 and 96 are all connected to each other and may be integral. Three brushes 34', 36' and 38' . -- 11 --7~6[) are fixed to an insulated mounting piece 98 on the housing and are connected in the same manner as contacts 34, 36 and 38 of Fig. 4. In operation, as the damper plate 24 rotates, contact plate 86 will connect either contacts 34', 38' together or will connect contact 36', 38' together, exactly in the manner of Fig. 4, to energize or shut off the motor 30 as required. The brushes 34', 36', 38' will wipe the contact segments continuously as the damper is used, to keep the contact segments clean. If desired, the contact plate 86 may be a transfer or decal which is applied by adhesive to the ; damper end plate 84. Normally the voltage used in the Fig. 9 embodiment will be a low voltage, for example 12 volts or 24 volts, to avoid dangers of shock to users.
If desired, the arrangement shown in Fig. 10 may be used, in which primed and double primed reference numerals indicate parts corresponding to those of Fig. 9.
In the Fig. 10 arrangement the contact plate 86' is placed on the housing 12 instead of on the damper plate 24, and contact ring 88' is insulated both from contact segments , 90', 92' and from contact segments 94', 96'. The damper plate 24' now carries a set of three wiping brushes 99, all connected together and mounted by an insulating ; mounting 100 on the damper plate. The brushes 99 serve to connect central annular ring 88' either to outer segments 90', 92' or to inner segments 94', 96' as required, again to achieve the desired two ~, way switching function. -It will be appreciated that the damper of the invention leads itself to central control, so that a .

1~7~&~) central processor receiving its inputs from thermostats in each room and connected to dampers in each room may control the heat level in each room of a home according to a predetermined program. Such an arrangement is shown diagrammatically in Fig. 11, where a central pro-cessor 101 is shown connected to a set of thermostats 102, 103, 104 and 105, one in each room, and also to dampers 108, 110, 112 and 114, each associated with a corresponding thermostat. The central processor, which may be any conventional processor, such as the many - mini-computers,(which are programmable) or microprocessors (which have fixed programs) now commercially available, may be,arranged to receive the temperature inputs from ,' thethermostats 102 to 105 and to control the dampers ~ ~-,~; 108 to 114 to control the room temperatures according ' to a selected program. The output from the processor to each damper is on three wires, as indicated by wires ' 116, 118, 120 for damper 114. The wires 116, 118 correspond to the wires of Fig. 4 between contacte ~- 20 50, 52 and contacts 34, 36 respectively and wire 120 corresponds to lead 60 of Fig. 4. The processor 100 thus applies power alternatively and sequentially to wire 116 or wire 118 to reverse the state of damper 114, exactly as in the Fig. 1 embodiment, i.e. the processor 100 in effect constitutes a number of program controlled two-way switches.
;~ In addition, as indicated in Fig. 11, each room ;' may also be equipped with an override switch 122, 124, ' , 126, 128. The override switches are also connected to the central processor 100. The central processor may be 75~

programmed so that when an override switch is operated, the central processor will shut off all the dampers except the damper for the room in which the override switch was operated. The shut off will remain effective for a selected period of time, for example five minutes, adequate to allow the output of the furnace to heat more quickly the room in which the override switch was operated. If desired the central processor may also be programmed to turn on the furnace during this period of time, to ensure that an adequate heat flow into the desired room is available.
Finally, when used with a central processor, the damper may omit the integral two-way switch and have instead simply an impulse switch, which sends a ~ pulse to the processor whenever the damper rotates to - its closed or open position. The impulse switch may be a microswitch actuated as described (by plates 42, 44) -or it may be any other conventional switch. When the processor receives the impulse, it then turns the motor of the damper off as required. In effect the processor then constitutes the two two-way switches previously described.

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Claims (9)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A forced air damper comprising:
(1) a housing having a passage for flow of air therethrough, (2) a damper plate, (3) axle means in said housing mounting said damper plate in said passage for continuous rotation in one direction through 360°, for said damper plate in a first position to close-said passage to flow of air there-through and in a second position rotated through an angle from said first position to open said passage to flow of air there-through, (4) an electric motor connected to said axle means for rotating said damper plate in said one direction when said motor is energized, (5) two way switch means having a motor lead connected to said motor and two contacts adapted to be connected to a second two way switch, and also including actuator means operable for causing connection of said motor lead alternately sequentially to one and then the other of said contacts, said switch means being in a first switch condition when said motor lead is connected to said first contact and being in a second switch condition when said motor lead is connected to said second contact, (6) said contacts of said switch means being mounted on said housing and said actuator means being mounted on said damper plate, said switch means and said actuator means being located for movement of said damper plate from said first to said second position in said passage to operate said actuator means to place said switch means in one of said switch conditions and for movement of said damper plate from said second to said first position to operate said actuator means to place said switch means in the other of said switch conditions.

2. A damper according to claim 1 wherein said damper plate is a flat plate and said passage is rectangular in configuration so that said damper plate closes said passage in two said first positions rotated 180° from each other and so that said damper plate provides a maxi-mum opening in said passge in two said second positions each being rotated 90° from said first positions, said actuating means including means for switching the condition of said switch means when said damper plate moves from one of said first positions to one of said second positions and when said damper plate moves from one of said second positions to one of said first positions.

3. A damper according to claim 1 and including ratchet means associated with said damper plate for preventing said damper plate from rotating in a direction reversed to said direction.

4. A damper according to claim 1, 2 or 3 and including a second two way switch having a pair of second contacts one coupled to each of said first mentioned contacts and having a switchable contact switchable between said second contacts, and a pair of power supply leads one coupled to said motor and the other to said switchable contact, so that when said second two way switch is operated, said damper plate will rotate in said direction from one of said positions to another of said positions to change the state of said damper from open to closed or from closed to open.

5. A damper according to claim 1, 2 or 3 including thermostatic switch means having temperature sensing means, actuator means operable in response to said temperature sensing means, and a second two-way switch connected to and operable by said actuator means, said second two-way switch having a pair of second contacts one coupled to each of said first mentioned contacts and having a switchable contact switchable between said second contacts, and a pair of power supply leads, one coupled to said motor and one to said switchable contact, so that when said second two way switch is operated, said damper plate will rotate in said direction from one of said positions to another of said positions to change the state of said damper from open to closed or from closed to open.

6. A damper system including a plurality of dampers according to claim 1 or 2, and including central processing means connected to said motor and to said two-way switch means of each damper, a thermostat associated with each damper and connected to said central processing means for providing temperature information to said central processing means for the area in which each damper is located, said central processing means being programmed to control the state of said dampers to control the temperature of said areas, and override switch means associated with each said damper and connected to said central processing means and each override switch means being operable to cause said central processing means to close for a selected interval at least some of said dampers except for the damper the override switch means of which has been operated.

7. A damper according to claim 1 wherein said switch means includes a single pole double throw micro-switch having an outwardly biased operating lever and said actuating means includes two quarter-circle shaped plates each located at one side of said damper plate at one end thereof and each projecting in opposite directions from said damper plate and being located in a common plane, said plates being located to depress said lever as they rotate therepast.

8. A damper according to claim 1, 2 or 3 wherein said switch means includes a contact plate comprising a central annular contact ring extending continuously around 360°, two outer annular contact segments each extending around an arc of 90° and spaced 90° apart from each other, and two inner annular contact segments each also extending around an arc of 90° and spaced 90°

from each other and located circumferentially between said outer annular contact segments; and three brushes one contacting each of said contact ring and contact segments of said contact plate, said contact plate being mounted on one of said housing and said damper plate, and said brushes being mounted on the other of said housing and said damper plate.

9. A forced air damper comprising:
(1) a housing having a passage for flow of air therethrough, (2) a damper plate, (3) axle means in said housing mounting said damper plate in said passage for continuous rotation in one direction through 360°, for said damper plate in a first position to close said passage to flow of air there-through and in a second position rotated through an angle from said first position to open said passage to flow of air there-through, (4) an electric motor connected to said axle means for rotating said damper plate in said one direction when said motor is energized, (5) switch means having a switch having a first and second switch condition, and also including actuator means operable for operating said switch, (6) said switch being mounted on said housing and said actuator means being mounted on said damper plate, said switch and said actuator means being located for movement of said damper plate from said first to said second position in said passage to operate said actuator means to place said switch means in one of said switch conditions and for movement of said damper plate from said second to said first position to operate said actuator means to place said switch means in the other of said switch conditions, (7) and control means connected to said switch and to said motor and responsive to changes in the condition of said switch means for controlling the operation of said motor.