US3548871A

US3548871A - Air flow control

Info

Publication number: US3548871A
Application number: US734976A
Authority: US
Inventors: James P O'grady
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 1968-06-06
Filing date: 1968-06-06
Publication date: 1970-12-22
Anticipated expiration: 1987-12-22

Description

I United States Patent 11113,543,371

[ 72] Inventor James P. OGrady [56] References Cited Evansville, [1111- UNITED STATES PATENTS P 734976 1,598,566 8/1926 Edwards 251/305x [221 FM 2 010 694 8/1935 Jones 251/3o5x Patented 1970 2 278 421 4/1942 Brown 251/305x 73] Assignee Whirlpool Corporation l on "kl 2,393,170 III 946 Kinney et a1. 25 l/308X "9" 3,093,981 6/1963 OGrady 62/408 3,230,971 1/1966 Rosaen 137/556.3 2,920,858 1/1960 Hunter 251/118 4 AIR FLOW ONTROL Primary Examiner-Henry T. Klinksiek [5 1 9 cums, 6 [game Attorney-Hofgren, Wegner, Allen, Stellman & Me Cord [52] US. Cl. 137/553,

251/305: 62/419; 138/37 ABSTRACT: An airflow control for use in apparatus such as a [51] Int. Cl. ..Fl6k 37/00, forced air refrigerator. The control includes a skewed vane F161: 1/22 damper regulating the amount of air delivered through a duct [50] Field of Search 137/553, having an outlet at one end. Manually operable means are pro- 554, 556.3; 25l/305308, 118, 120, 121; 62/408, vided for adjustably disposing the damper providing an im- 419; 138/37 proved range of control of airflow.

AIR FLOW common BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to airflow control means and, in particular, to dampers for use in airflow ducts.

2. Description of the Prior Art ln forced air refrigeration apparatuses; such as freezerrefrigerators, the amount of airflow is controlled by dampers adjustably closing portions of the airflow system. The conventional damper for such use comprises a flat structure which selectively blocks more or less of theflow passage as a function of translation of the damper. In one conventional form of such damper, the damper is rotatably mounted so as to be positioned in a number of angularly related positions providing different flow conditions. A serious disadvantage of the known dampers is the lack of correlation between the damper position and the throttling of the airflow. Illustratively, in such known dampers, a substantial amount of movement of the damper must be effected before an appreciable amount of throttling is effected. It has been found-in conventional dampers that the user may be required, to position the damper almost halfway between the fully opened and the fully throttling position before an appreciable amount of throttling is obtained.

It is conventional in such dampers to provide indicia for indicating the position of the damper and such indicia are misleading to the user as they do not effectively indicate the airflow throttling because of the above'discussed lack of correlation between the angular damper position and the airflow throttling effect.

SUMMARY OF THE INVENTION The present invention comprehends an improved airflow control means utilizing a novel damper structure which provides substantially improved correlation between the angular damper position and the airflow control condition. The damper of the present invention includes a pair of generally oppositely extending vanes which are skewed one to the other and disposed adjacent the end of the flow passage into which the outlet opens to provide a control of the airflow having improved correlated relationship to the angular disposition of the damper. I

BRIEF DESCRIPTION OF THE DRAWING Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein: v

FIG. 1 is a fragmentary side elevation of a refrigeration apparatus having an airflow control embodying the invention with portions broken away for facilitated illustration thereof;

FIG. 2 is a fragmentary enlarged vertical section of a portion of the apparatus provided with an improved airflow control damper embodying the invention;

FIG. 3 is a front elevation thereof;

FIG. 4 is a graph illustrating the airflow control effected by the damper of the present inventionas compared to a'conventional straight damper;

FIG. 5 is a front elevation of an alternate embodiment of the improved airflow control damper of the invention; and

FIG. 6 is a front elevation of still another alternate embodiment of the improved airflow control damper of the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment of the invention as disclosed in the drawing, a refrigeration apparatus generally designated 10 is shown to include an insulated cabinet 11 having an upper front door 12 providing controlled access to an upper freezer chamber 13 and a lower door 120 providing access to a lower refrigerator chamber 14. Air is refrigerated by means of a conventional evaporator 15 disposed in a center mullion 16 and drawn therethrough by a suitable blower 17 which discharges the refrigerated air upwardly through a vertical duct i8 and through a first outlet 19 into freezer chamber 13. A portion of the air delivered upwardly through the duct 18 is forced into the inlet 20 of a transfer duct 21 which has an outlet 22 opening from a narrowing end portion 23 of the transfer duct flow passage 24. The refrigerated air is conducted downwardly from the outlet 22 through a rear duct 25 which opens at its lower end to the refrigerator compartment 14.

Under normal conditions, the refrigeration in apparatus 10 is controlled by a thermostat 26 which, illustratively, may be located in the refrigerator chamber M so that the freezer chamber 13 receives cold air until such time as the refrigerator chamber 14 reaches the desired low temperature to terminate further refrigeration operation of the apparatus. To adjust the temperature within freezer chamber I3, a damper device generally designated 27 is provided in the transfer duct 21 for controllably throttling the refrigerated air delivery to the duct 25 and, thus, to the refrigerator compartment 14 so that a volume of cold air sufficient to maintain a desired freezing temperature is delivered to the freezer compartment I3 before the thermostatically set temperature of the refrigerator chamber 14 is reached.

The device 27 includes a damper generally designated 28 provided with a midportion 29, a first vane 30 comprising a first section 40 having a second section 41 attached thereto in skewed relationship extending outwardly from the midportion 29, and a second vane 31 extending generally oppositely outwardly from the midportion. The midportion 29 is carried on a pivot 32 as shown in FIG. 2 for pivotal movement about an axis 33 transverse to the flow passage 24. A manual control knob 34 is carried on the forward end of the pivot 32 for manually rotating the damper 28 for selectively positioning the damper in any one of a plurality of angularly related positions, including a maximum throttlingposition transversely to the passage 24, as shown in dot-dash lines in FIG. 3, and a maximum open position substantially aligned with the flow passage, as shown in dashed lines in'FIG. 3. As shown in FIG. 2, the vanes may extend substantially the full depth of the flow passage end portion 23 and in the fully opened position, vane 31 extends substantially parallel to the longitudinal extent of the flow passage 24, whereas in the fully throttling position, vane 31 extends substantially perpendicularly thereto.

Shown in FIG. 5 is an alternate embodiment of the control damper generally designated 28a. Damper 28a is provided with a midportion 29a, a first vane 31a extending from midportion 290, and a second vane 30a extending generally oppositely outwardly from the midportion in skewed relationship to vane 31a. FIG. 6 shows still another form of the damper structure generally indicated 28b. Damper 28b includes a midportion 29b having a first vane 31b extending outwardly therefrom and a second curved vane 30b extending generally oppositely outwardly from midportion 29b. Obviously, either damper structure 28a or 28b could be substituted for damper 28 in the airflow control system shown in FIG. 3 with results similar to those outlined above.

As shown in FIG. 3, outlet 22 opens into duct portion 23 which narrows toward the outlet 22. The pivot axis 33 is disposed relatively closely adjacent the outlet 22 in the end portion 23. As seen in FIG. 3, the width of the damper, i.e., the vane tip-to-vane tip dimension thereof is slightly less than the corresponding width of the outlet 22 so that in the maximum throttling position, the outlet is not completely closed but some airflow is permitted therethrough.

. The control knob 34 is disposed forwardly of a front panel the damper position is more accurately correlated with the airflow volume than in conventional damper controls utilizing straight dampers. Thus, illustratively, in a refrigeration apparatus wherein the structure is as shown in the drawing, but the damper comprises a straight damper having a vane tip-tovane tip dimension of approximately 2 /2inches, it may be seen that the air flow decreases relatively little between

damper positions

1, 2 and 3. Substantially all of the airflow control is effected by movement of the damper to positions 4 and 5. This presents an undesirable condition as the user normally would expect to obtain substantially equal incremental control of the airflow for equal angular dispositions of the control knob 34.

Damper 28, however, provides an improved correlated airflow relative to the angular damper position, as shown in FIG. 4, wherein a generally similar reduced. control is obtained between positions 1 and 2 and positions 4 and 5, with a somewhat greater control being provided between

positions

2 and 3 and positions 3 and 4.

While the airflow control of the present invention is extremely simple and economical of construction, it provides the highly desirable improved facilitated control functioning discussed above in a novel and simple manner.

lclaim:

1. Airflow control means comprising: a duct defining an airflow passage having an end portion; an outlet in said duct opening to said end portion; a damper having a midportion, a first vane extending outwardly from said midportion, and a second vane extending outwardly from said midportion skewed to said first vane; means for adjustably positioning said midportion rotatively about an axis transverse to said flow passage for selectively positioning said damper at said end portion in any one of a plurality of angularly related positions, including a maximum throttling position substantially transversely across said flow passage, and a maximum open position substantially aligned therewith, said damper defining means providing maximum and minimum rates of airflow at the corresponding maximum throttling and maximum open positions and a rate of airflow substantially midway between the maximum-minimum rates of flow when the damper is substantially midway between said maximum throttling and its maximum open positions.

2. Theflow control means of claim 1 wherein said outlet opens to said flow passagesubstantially parallel to said axis.

3. Theflow control means of claim 1 wherein one of said vanes extends perpendicularly to said flow passage in a maximum throttling position; v

4. The flow control means of claim 1 wherein one of said vanes extends parallel to said flow passage in said maximum open position.

5. The flow control means of claim 1 further including an outlet duct'conducting air from said outlet in a direction reverse to the direction of airflow through said passage, said first named duct and said'outlet duct being defined by a common wall therebetween.

6. The flow control means of claim 1 including means for manually angularly positioning said damper including indicia means for indicating the angular disposition thereof having a middle indicium corresponding to a half-open condition of said damper.

7. Airflow control means comprising: a duct defining anairflow passage having an end portion; an outlet in said duct opening to said end portion; a damper having a midportion, a first vane extending outwardly from said midportion, and a second vane extending outwardly from said midportion skewed to said first vane; means for adjustably positioning said midportion rotatively about an axis transverse to said flow passage for selectively positioning said damper at said end portion in any one of a plurality of angularly related positions, including a maximum throttling'position substantially transversely across said flow passage, and a maximum open position substantially aligned therewith, said airflow passage end portion narrowing toward said outlet.

8. The flow control means of claim 7 wherein said damper is disgosed in said end portion".

The flow control means of claim 7 wherein the width of said damper is substantially-less than the corresponding width of said outlet transverse to said passage.