US 2790372 A
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Description (OCR text may contain errors)
April 30, 1957 E. R. COOPER DAMPER ASSEMBLY Filed March 30, 1953 L35 INVENTOR EzgeneR. loo r ATTORNEY United States Patent DAMPER ASSEMBLY Eugene R. Cooper, Asheville, N. C.
Appfication March 30, 1953, Serial No. 345,313
3 Claims. (CI. 98-41) a diffuser of some type is mounted in the ceiling opening so that the blast of air issuing into the room will not be felt by a person directly beneath the opening. Such diffusers are available in a wide variety of sizes and designs and are well known in the art.
Heretofore no provision has been made for automatically controlling the amount of air entering each room through such a ceiling opening or diffuser. Most diffuser units used in ceiling openings are provided with a manual adjustment for controlling the flow of air through the unit, but such manual adjustment is necessarily difficult and unsatisfactory in view of the remote location of the unit and since it requires frequent adjustment. The present invention is concerned with a method for eliminating these difiiculties.
This invention comprises a damper assembly which may be readily connected to a duct above a ceiling diffuser for the purpose of automatically controlling the amount of air passing from the duct through the ceiling diffuser. The damper is controlled by a thermostat mounted within the room below.
Details of the invention will be explained by reference to the accompanying drawing, wherein:
Figure 1 is a perspective of one embodiment of the invention showing the damper in closed position.
Figure 2 is a sectional view taken along the line 2 2 in Figure 1 and showing the assembly of Figure 1 mounted in an air conditioning system. In Figure 2 the damper is in open position.
Referring now to Figure 1, there is shown a base member 1 constructed of sheet metal and having mounted thereon a damper 2. The damper comprises a substantially square thin sheet of sheet metal hinged at ,3 so that it may be raised to expose an opening (not shown) in base member 1 directly beneath the damper 2. Mounted on base member 1 adjacent hinge 3 is U-shaped sup.- porting member 4. Supporting member 4 is provided with two aligned holes, one near the top of each vertical leg of supporting member 4. There is also mounted on base member 1 an electrical control motor and related reduction gear assembly 5, provided with a driven shaft 6. Shaft 6 passes through the two aligned openings in supporting member 4. Shaft 6 is biased toward connecting socket member 7 on gear assembly by means of a spring 8. Spring 8 is concentrically disposed around shaft 6 and is normally held under slight compression by means of cotter key 9 and one of the upright legs of supporting member 4. The purpose of spring 8 will be discussed further below. The free end of shaft 6 is provided with a radial extension 10. Mounted onTextension 10 is a rotatable wheel or sheave 11. A cable 12 which passes over sheave 11 is connected at 13 to damper 2 and at 14 to the base member 1, as shown. It will thus be apparent that as the shaft 6 rotates in a clockwise direc-. tion (looking toward the motor from the shaft) sheave 11 will be carried in a clockwise direction through the arc defined by the extension 10 with the result that cable 12'.
will be lifted and damper 2 will be opened. With the damper open, if theshaft 6 rotates an additional one-half revolution in a clockwise direction, the damper will be closed.
Electric control motor and related reduction gear assembly 5 is a standard type electric janitor control motor, commercially available, and is adapted to rotate shaft 6 approximately one-half of a complete revolution in response to a signal from a standard thermostat 15.
Such a secondary transformer type control motor is commercially available from the Minneapolis Honeywell Corporation, Minneapolis, Minnesota, and is well kown in the art of air conditioning and heating. The thermostat 15 will, of course, be mounted in the room below the damper. nected to supply the proper voltage to the motor and reduction gear assembly 5.
The method in which this automatic damper-operates is believed to be obvious from the foregoing description.
If the installation is to be used in a heating system,-
when the temperature in the room reaches the lower limit at which the thermostat 15 is set, the electric m'otor and reduction gear assembly 5 receives electric current and rotates shaft 6 in such a manner as to open damper 2. When the temperature in the room satisfies the thermostat, the motor and reduction gear assembly 5 rotates the shaft 6 an additional one-half of a revolution; closing damper 2. 1 v 1 An important advantage of the present invention is that it provides a completely assembled damper unit ready to be attached to a duct. It will be observed in the drawing that base 1 is provided with holes 17, 18, 19,
20, etc. so that it maybe readily connected to the bottom of the duct by means of sheet metal screws. The opening cut in the bottom of the duct is only large enough to accommodate that part of the base member I carrying the damper 2 and U-shaped supporting member 4. The motor and gear assembly 5 is, then, disposed outside the duct. This permits subsequent servicing and prevents dirt or grease from the motor being transferred to the air in the duct. The shaft 6, of course, must pass through the side of the duct in the completed assembly, and it is in this connection that the spring 8 surrounding the shaft 6 has its primary use.
The installation in a duct of the complete damper unit shown in Figure 1 is accomplished as follows: First, an opening is cut in the bottom of the duct adjacent one side thereof of sufficient size to accommodate that part of the base member carrying the damper and U-shaped supporting member. This opening is cut adjacent one side of the bottom of the duct in order that the shaft may protrude through that side of the duct and make connection with the motor and gear assembly 5 mounted outside the duct on the base member 1. Next, a small hole is cut in the side of the duct at the proper location to accommodate the shaft 6. Then, to mount the base member and its component parts on the duct, the shaft is disconnected at the motor and pressed outwardly away from the motor, compressing spring 8. With the shaft in this condition, the base member 1 is placed in position over the opening in the bottom of the duct. The damper and the U-shaped supporting member, of course, fit up inside the duct and the shaft 6, biased by the compressed spring, slides along the side of the duct until it Patented Apr. '31 1957 4 If necessary, a transformer 16 may be con-'- it slips through the hole and.may be connected to the motor and gear assembly outside the duct through connecting. socket inembe'rl 7.. The base: niembenli-isthen connected to the duct by meansofscreWs and thecasseth-Z' bl'y is.cornplete. .Very satisfactoryresults :areobtained by the? use of a shafthaving a hexagonal head or end in combination with a socket member having ahexagonalshaped recess therein.
recess to provide a drivingconnection between the motor and the 'shaft.
Figure 2 shows the assembly of Figure I mounted ona duct with the damper inlopen position. The'base unit,
, horizontal arrows, is such that whenthe. damper 2 is opened a portion of the air will be diverted by the damper Zan'd directed via conduit 23 through difiuser 24 into the room below. When damper 2 is closed, of course, al l' of the air flowing through the duct 20 will by-pass conduit, 23, The motor, andgear assembly,;n ot shown in Figure- 2, is located outside the-duct 20 with the shaft extending through the 'side wall of the duct. In this location, the motor and gear assembly are accessible for servicing or. repair and are completely isolated from the moving air in the duct.
The assembly illustrated and described may easily be i installed either in an existing'air distributing system or in a new system being built. While a single embodiment of the invention has been described, it will be. apparent that various changes and modifications may be'rnade therein without departing from the spirit of the invention.
What is claimed is: 1. In an air distributing system, an air supply duct extending horizontally above the ceiling in a room, said ducthaving an opening inthe lower side thereof, a-;base
member attached-to the outsideof said duct and. provided with-Tan opening infiuid communication with the opening in said duct, a damper connected to saidbase member and disposed inside said duct, an electricgmotor providing a source of rotaryp'ower disposed outside said duct, a thermostatic control forsaid motor, a shaftconnected in driving relation to said motor, means responsive to the rotational movement of said shaft to cause said damper to open and close'saidopening in said base member,
means to disconect said shaft from saidimotor to permit The spring member, of course, tends to. constantly urge the end of the shaft into the longitudinal movementof saidrshaft and resilient means urging said shaft toward said motor.
2. In an air distribution system, an air supply duct extending horizontally above the ceiling in a room, said duct having an opening in the lower side thereof, a base member attached to the outside of said duct and provided with an opening in fluid communication with the opening in said duct, a fiat damperdoor pivotallyconnected to said base member and adapted to intercept a portion of the air flowing through said duct when said door is in open position, an electric motor providing a source of rotary power disposed outside said duct and attached to said base member, a shaft supporting element connected to said base member and disposed inside said duct, a rotatable shaft detachably connected to said motor and extending from said motor through the side of said duct and supported by said shaft supporting element, and means connecting-said shaft tosaid door to cause said door to open and, close in response to rotary movement by said shaft.
3. In combination; a flat metal basemember having an opening therein, a flat door member pivotally connected to said base member and adapted to fit over said opening, an electric motor providing a source of rotary power mounted near the edge of said base member, a shaft supporting element connected to said base member, a rotatableshaft supported by said elementand extending between said element and said m'otor, an arm extending normal to the axis of said shaft and connected tosaid shaft, a sheave connected to said arm, the axis of said sheave being substantially parallel to the'axis of said shaft, resilient means urging said shaft toward said motor, means to connect said shaft to'said motor for rotation thereby and means to disconnect said shaft from said motor to permit longitudinal movement of said shaft, and a flexible cable extending from said door to said base member, said cable beingconnected to said door and said base member and adapted to intercept a groove on saidsheave whereby upon rotation of said shaft said door is opened for closed.
References Cited in the file of this patent UNITED STATES PATENTS