Automatic damper means and controls therefor

Abstract

An automatic damper means and controls, which provide an exceedingly safe automatic damper for the exhaust duct-work of an associated gas furnace or the like, by automatic control of the damper, and automatic control of the gas supply, with redundancy features for providing exceedingly safe operation.

Description

The present invention relates to an automatic damper means, such as for gas furnaces, and to control means therefor; and concepts provide exceeding high safety, with ample redundancy as to the control of the combustion gas, and with automatic control of the actuation and setting of the damper as to assure safety.

It has been long known that many installations such as gas furnaces and the like, utilizing the combustion of fuels, would be more effective if an amply-safe means could be provided for automatically controlling the flue or exhaust ducts thereof so as to cause the exhaust duct-work to be closed during idle periods of the equipment yet automatically open if the equipment was in its combustion mode or operation.

Obviously, the products of combustion of fuel are or can often be very dangerous and even fatal to human beings if not safely exhausted; and thus the lack of an effective and fool-proof automatic damper control has long meant that no automatic damper means has been permitted to be used.

Obviously, also, much heat has been wasted, by exhaust flues being always open, as is generally considered to be necessary for most persons would forget to open any closed damper prior to utilizing a furnace or heater; and thus no heat-saving dampers are provided for such equipment. Even as to fireplace installations which do have dampers, many homeowners leave them always open, once they have experienced an accident of leaving them closed during operation.

Accordingly, the present concepts of a reliable and amply safe automatic damper, with features of redundancy as to safety factors, provide a very advantageous installation achieving a tremendous savings in heat energy presently wasted, yet providing high safety nevertheless.

Further, the concepts provide that the damper unit may be relatively easily installed, as a unit, which contains the damper and the controls therefor, and, further, the concepts provide extra safety by heat-sensitive components easily mounted to components, such as the draft diverter, which are generally easy and convenient to reach, and being having the cam-arm 104 bent to provide a generally semi-cylindrical extension 108, of slightly less than 180° in extent. This curved extension 108 is shown as engageable with the control arm 50 of microswitch 32, being effective as shown in FIG. 3 to hold that microswitch 32 in switch-closed position in the FIG. 3 position in which the damper 10 is in duct-closed position; although the curved extension 108 is shown in FIG. 4 to be out of engagement with control blade 50 of microswitch 32 in the FIG. 4 position in which the damper 10 is in duct-open position.

Further electrical control, by the cam member 48, is also achieved by its having its pin 98 extending (leftwardly in FIG. 1) past the location in which it receives the control links 94, sufficiently far such that the outer (leftward in FIG. 1) end of pin 98 moves in a path which brings it into contact with the control blade 52 of microswitch 34. This engagement of cam-pin 98 with control blade 52 of microswitch 34 is shown in FIG. 4 as being such as to have that control blade 52 in switch-closing position, in the FIG. 4 position in which the damper is in duct-open position; but the cam-pin 98 is shown in FIG. 3 as being removed from the control blade 52 of microswitch 34 in the FIG. 3 position in which the damper 10 is in duct-closed position.

The location of the control cam 48 is thus seen to be controlled as shown by the motor 36. That is, the output-shaft 100 of the motor 36 is the shaft which carries the control cam 48, that mounting of the control cam 48 being by the set screw 102 as mentioned above, the said screw 102 passing through a threaded opening 110 (FIG. 5) to bear upon the drive shaft 100 which has passed through an opening 112 in an ear 114 shown as integrally formed by suitably bending or otherwise forming the control cam 48.

Further, the location of control cam 48 with respect to the location of its mounting shaft 100 within the control unit 12 is also by the motor 36. That is, the motor 36 is shown as having a frame which has support ears 116 which are held as by screws 118 to an up-standing mounting lug or bracket 120 which extends from the rear wall 72 of control unit 12.

The two microswitches 32 and 34 are shown as mounted, as by screws 122 which extend through the microswitches 32 and 34, and through a intervening insulator or spacer 124, into the rear wall 72 of control unit 12; and the mounting of those microswitches 32 and 34 is, as shown in FIG. 1, such that their respective control blades 50 and 52 are in operative alignment, respectively, with the paths of curved cam extension 108 and the outer (leftward in FIG. 1) portion of the cam pin 98.

Further as shown in FIG. 10, it will be noted that all the circuitry and electrical components except the drive motor 36 and the switch 32 are shown as provided on low-voltage side of a step-down transformer 126, suitably reducing the voltage from power voltage of main power circuit 37.

It is thus seen that an automatic damper means and controls therefor, according to the present inventive concepts, provides a desired and advantageous device and installation yielding the high advantages of an automatic damper for exhaust ducts of a gas furnace or the like, which is conveniently installed as a unit, and which provides not only automaticness of operation but a high degree of safety. Thus, when the equipment is not operating, the damper is closed, thereby eliminating the tremendous waste of room heat which is otherwise wasted by going up the exhaust duct or stack; but when the equipment is operating, the damper is automatically assured of being open. Any heat build-up in the exhaust stack automatically shuts down the fuel supply.

Accordingly, it will thus be seen from the foregoing description of the invention according to this illustrative embodiment, considered with the accompanying drawings, that the present invention provides new and useful concepts of an automatic damper and control, yielding desired advantages and characteristics of actuation, energy savings, and exceedingly high safety, thus accomplishing the intended objects, including those hereinbefore pointed out and others which are inherent in the invention.

Modifications and variations may be effected without departing from the scope of the novel concepts of the invention; accordingly, the invention is not limited to the specific embodiment or form or arrangement of parts herein described or shown.

Claims

1. damper control means for a damper means of a flue duct, which is provided with support means which support the damper means in the associated duct-work in and between a duct-open and a duct-closing position, comprising, in combination:

crank means operatively connected to the support means;

link means for rotating the crank means;

movable first control means for moving the link means to rotate the crank means;

drive means for moving the movable control means for rotating the crank means; and

actuation control means for actuating the said drive means, and operative in response to an associated thermostat means and to the previous movement of the drive means to actuate the drive means so as to cause and permit only movement thereof sufficient to rotate the crank means between the duct-closing and duct-open positions of the damper means.

2. The invention as set forth in claim 1 in a combination in which the said control means not only moves the link means but also controls the said actuation control means to achieve its operativity as stated.

3. The invention as set forth in claim 1 in a combination in which there are provided a pair of switch means in the actuation control means, one of which is operative to energize the drive means between the stated limits and the other of which is operative to permit energization of the drive means for a subsequent cycle even though the first has been caused by a previous cycle to be in non-energizing setting as the energizing the drive means.

4. The invention as set forth in claim 3 in a combination in which there is also provided a switch means which controls fuel supply to the associated heat means whose combustion products are vented by the flue duct, and the said control means comprises a cam member having a first portion which is operative to control the first of said switch means, and a second portion which is operative to control the switch means which controls the fuel supply.

5. The invention as set forth in claim 4 in a combination in which the said second portion of the control means also is supportingly connected to the said link means for providing the controlled movement thereof which rotates the crank means and thereby also the damper means.

6. The invention as set forth in claim 4 in which the said first portion of the control means cam member is provided as a curved cam component, and the said second portion of the control means cam member is provided as a pin means.

7. The invention as set forth in claim 5 in which the said first portion of the control means cam member is provided as a curved cam component, and the said second portion of the control means cam member is provided as a pin means.

8. An automatic damper means for an associated gas furnace or the like, having damper control means according to claim 1, the automatic damper means also including a damper means and a control means both provided on a section of duct which is adapted to be installed as a unit into the exhaust duct-work of the associated furnace or the like, and in which the damper means includes a damper plate means having at least two relatively large components which are movable relative to one another.

9. A damper for a duct of a gas furnace or the like, having a damper control means according to claim 1, in which the damper includes a plate means which in duct-closing position extends generally transverse to the duct for blocking exhaust flow through the duct, the improvement which comprises providing the plate means in at least two parts, and providing that in their most fully duct-closing position there it still a significant area not blocked thereby, the non-blocked are a being large enough to permit gas leakage to draft upwardly.

10. The invention as set forth in claim 9 in which there are two plate means, they being supported in a slightly spaced manner such that in most duct-closed position the spacing therebetween provides the said gas-leakage area.

11. A damper means for the flue gas duct of a gas furnace or the like, according to claim 1, in which the damper means is provided to be a plate means comprising at least two parts which are relatively movable with respect to one another, there being support means and control means which supportingly position the parts of the damper plate means in and between duct-open or duct-closed position.

12. A damper means for the flue gas duct of a gas furnace or the like, according to claim 1, in which control means are provided as to the fuel supply which are responsive to heat build-up in the draft diverter of the associated furnace or the like, the sensing component or components of the control means being located in the region of the draft diverter.

13. A damper means for the flue gas duct of a gas furnace or the like, as set forth in claim 12, in which the heat-responsive control means, which sense heat-buildup in the draft diverter, also are operative, upon sensing such heat-buildup in the draft diverter, to de-energize the actuation means of the damper.

14. damper control means for a damper means of a flue duct, which is provided with support means which support the damper means in the associated duct-work in and between a duct-open and a duct-closing position, comprising:

crank means operatively connected to the support means;

link means for rotating the crank means;

movable first control means for moving the link means to rotate the crank means;

drive means for moving the movable control means for rotating the crank means;

actuation control means for actuating the said drive means, and operative in response to an associated thermostat means and to the previous movement of the drive means to actuate the drive means so as to cause and permit only movement thereof sufficient to rotate the crank means between the duct-closing and duct-open positions of the damper means;

and in which there are provided a pair of switch means in the actuation control means, one of which is operative to energize the drive means between the stated limits and the other of which is operative to permit energization of the drive means for a subsequent cycle even though the first has been caused by a previous cycle to be in non-energizing setting as to energizing the drive means;

in a combination in which a first portion of the control means controls one of the said switch means and a second portion of the control means is a pin means which controls the second of the switch means and also is supportingly connected to the said link means for providing the controlled movement thereof which rotates the crank means and thereby also the damper means.

15. A damper control means for a gas furnace or the like in which heat-sensitive means are provided in the draft diverter opening component of the associated furnace, and is operative, in response to heat build-up therein caused by any blockage of the exhaust stack above the draft diverter component, which heat build-up causes spillage of hot flue gases out of the opening of the draft diverter hood, to close the associated energy-supply to the said furnace or the like, the heat-sensitive means being of a type which achieves that energy-supply closing in response to an increase of heat at the location of the said draft diverter opening;

in which the said heat-sensitive means includes a pair of heat-sensitive components, each of which is operative in response to heat build-up in the draft diverter to close the associated energy-supply to the said furnace or the like; and one of the heat-responsive components is in a thermocouple circuit independent of line voltage, thereby providing special safety means for achieving energy-supply shutoff not only independently of line voltage but also in circuitry which is non-electrically resettable, avoiding thereby any cycling or flutter of the control thereby achieved for the energy-supply means by the heat-responsive component of the thermocouple circuit, and also thereby avoiding any possibility of continuation of exhaust gas spillage out the draft diverter once the thermocouple circuit's heat-responsive component has achieved energy-supply shutoff even momentarily.

16. A damper control means for a gas furnace or the like in which heat-sensitive means are provided in the draft diverter opening component of the associated furnace, and is operative, in response to heat build-up therein caused by any blockage of the exhaust stack above the draft diverter component, which heat build-up causes spillage of hot flue gases out of the opening of the draft diverter hood, to close the associated energy-supply to the said furnace or the like, the heat-sensitive means being of a type which ahcieves that energy-supply closing in response to an increase of heat at the location of the said draft diverter opening;

in which the said heat-sensitive means includes a heat-sensitive component which is operative in response to heat build-up in the draft diverter to close the associated energy-supply to the said furnace or the like; and the heat-responsive component is in a thermocouple circuit independent of line voltage, thereby providing special safety means for achieving energy-supply shutoff not only independently of line voltage but also in circuitry which is non-electrically resettable, avoiding thereby any cycling or flutter of the control thereby achieved for the energy-supply means by the heat-responsive component of the thermocouple circuit, and also thereby avoiding any possibility of continuation of exhaust gas spillage out the draft diverter once the thermocouple circuit's heat-responsive component has achieved energy-supply shutoff even momentarily.