Weather Curtain For Airplane Hangar Entrance

Abstract

A pass-through curtain suspended across the entrance of a large enclosure such as an airplane hangar or other building has an inner and outer series of transparent, back-to-back, depending closure flaps which are arranged in overlapping relationship with one another to prevent the escape of temperate air from the hangar or the inflow of ambient air when the hangar door is open, yet allow the forced entry of an airplane by deflecting and parting of the flaps. A substantially air-impervious barrier portion of the curtain above the pass-through, flap portion and along each end thereof precludes air flow through areas of the curtain other than the flap portion to thereby further reduce the total volume of air passed by the curtain. A transverse, air-inflated, stiffening tube extending across the curtain slightly above the flaps and an individual, vertically extending stiffening tube on each flap rigidify the curtain and flaps so that the flaps quickly return to their undeflected positions instead of clinging to the wings and tail structure of the airplane as it moves through the curtain. Zippered pockets of granular weight material along the bottom of the flaps provide variable ballast.

Description

This invention relates broadly to closure structures for the entrances of large enclosures such as aircraft hangars and the like and, more particularly, to a special pass-through, weather curtain mounted across the entrance of such an enclosure, which minimizes the inflow and outflow of air through the entrance during ingress and egress of objects such as airplanes from the enclosure.

Hangars of many diverse sizes and configurations have been provided in the past to accommodate airplanes for both storage and maintenance purposes. In many instances, such hangars encompass a wide expanse of floor area and are sufficiently tall to accommodate aircraft with high tail sections. Thus, large open areas are presented which cause difficulty in heating and cooling the hangar to maintain comfortable working conditions, particularly in those climates where extreme heat or cold is experienced.

For example, in environments of extreme cold, it may be difficult in the first instance to bring the area within the hangar up to a comfortably warm temperature and to maintain it at such temperature, even with the hangar door fully closed. When the door is subsequently opened for entry or exit of an airplane, a large amount of the heat within the hangar may be lost through the hangar entrance, particularly in those situations where strong, gusty winds prevail. Moreover, since the door must remain open for a substantial period of time to allow the airplane to fully clear the hangar entrance before once again closing the door, further heat loss is experienced as a function of the time the door remains open. In situations where the heat loss is particularly severe, it may be several hours before heating equipment for the hangar can once again bring the temperature to a comfortable level. Hangars having unusually busy traffic patterns are more susceptible to heat loss than others, and may even render it virtually impossible to maintain a comfortable, working temperature within the hangar.

Similarly, in climates where air conditioning is required to cool the hangar interior to a comfortable working temperature, conditioned air is lost when the hangar door is opened, thereby creating unpleasant working conditions and causing the air conditioning equipment to function inefficiently.

Accordingly, one important object of the present invention is to provide a special pass-through weather curtain suspended across the entrance of an enclosure such as a hangar immediately behind the door thereof which is designed to maintain substantial continuity of working conditions within the hangar when the door thereof is opened for passage of an object such as an airplane through the curtain and entrance.

Another important object of the present invention is to provide a weather curtain as aforesaid having a substantially solid, air-barrier upper portion through which neither air nor parts of the object such as an airplane pass and a lower pass-through portion which yields to the forced entry of the object, but not to the efforts of air seeking to flow through the entrance.

A further important object of this invention is to provide a special weather curtain having barrier and pass-through portions as set forth above wherein the pass-through portion is only as large as that necessary to accommodate the largest airplane or other object anticipated, thereby maximizing the air-repelling area of the curtain to maximize its ability to maintain continuity of working temperature within the hangar.

An additional important object of this invention is to provide a double series of side-by-side, depending flexible flaps in the pass-through portion of the curtain wherein the flaps of one series overlap those of the other series to close slits presented between adjacent flaps which would otherwise permit airflow therethrough.

Yet another important object of the instant invention is the provision of an inflated stiffening tube which extends across the curtain slightly above the flexible, pass-through flap portion thereof and individual, vertically extending stiffening tubes on the flaps to increase the structural rigidity of the curtain and flaps to an extent that clinging of the flaps to the wings and tail structure of the airplane passing through the curtain is strongly resisted.

Other important objects of this invention include providing ballast-increasing weight pockets filled with granular material along the bottom of each flap; constructing the flaps of transparent material to provide full and clear vision during entry and exit of an airplane; and providing a curtain which is capable of carrying out all of the above object without detracting from its ability to be raised and lowered by wrapping and unwrapping the same from around a storage cylinder or roll.

In the drawing:

FIG. 1 is a fragmentary elevational view of an enclosure in the form of a hangar employing a weather curtain which embodies the principles of the present invention, the hangar door being shown in a fully raised condition to reveal the curtain there behind, and the outline of an airplane behind the curtain being indicated in phantom;

FIG. 2 is a fragmentary, vertical cross sectional view through the hangar taken along line 2--2 of FIG. 1;

FIG. 3 is an enlarged, fragmentary cross sectional view through the curtain taken along line 3--3 of FIG. 1;

FIG. 4 is an enlarged, fragmentary cross sectional view through the hangar and curtain taken along line 4--4 of FIG. 1;

FIG. 5 is an enlarged, fragmentary horizontal sectional view through one sheet of the curtain showing the valve fitting for the stiffening air tube of the curtain; and

FIG. 6 is an enlarged, fragmentary view of the front of the curtain showing the individual stiffening tubes on the flaps, the front sheet and flaps of the curtain being partially broken away to reveal the rear sheet and its flaps.

An enclosure 10 in the form of an aircraft hangar may assume any one of a variety of configurations and has an entrance 12 closable by a door 14 which may be of any suitable character, here indicated as being of the vertically folding type. The weather curtain assembly of the present invention, denoted broadly by the numeral 16, is disposed immediately behind door 14 and includes a curtain 18 suspended across entrance 12 by an idler roll 20 and an actable motor 22 which provides power for raising and lowering of curtain 18. A driven roll 24 operably coupled with motor 22 provides a base upon which the curtain 18 may be rolled when not in use.

The curtain 18 includes a pair of back-to-back, identical sheets 26 and 28 of canvass or other suitably air-impervious material and has a generally upper, barrier portion defined by the flat expanse of sheets 26 and 28, and a lower, pass-through portion defined by a large opening 30 in each sheet. Marginal side extensions of the barrier portion are presented by marginal edge sections 32 on each sheet 26 and 28 on opposite ends of their respective openings 30. The sheets 26 and 28 are sewn together at least in two places along seams 34 and 36 as shown in FIG. 3 so that the openings 30 are in exact registration with one another and are maintained in such registration even during raising and lowering of curtain 18.

The openings 30 of sheets 26 and 28 are ach of such a size and configuration to minimize the pass-through portion of curtain 18 so that a large expanse of curtain 18 may be devoted purely to resisting the flow of air into or out of hangar 10 during passage of an object such as an airplane through entrance 12. In this respect, it is important that each opening 30 conform generally to the basic shape of the object, in this instance an airplane 38. For airplane 38, each opening 30 has a lower, rectangular main area 30a which is adapted to clear the fuselage 40 and wings 42 of the airplane 38 and an upper, centrally located area 30b which adjoins and communicates with area 30a to clear the tail structure 43 of the airplane 38. It will be seen that by limiting the width and height of central area 30b to a size which is just sufficient to clear the largest and tallest tail structure 43 of an airplane contemplated to be using entrance 12, a relatively large expanse of curtain 18 may be retained on opposite sides of area 30b to function as a barrier and resist outflow or inflow of air through entrance 12.

The presence of the additional barrier area on opposite sides of open area 30b is especially important when it is considered that the hangar 10 may be situated in an environment of extremely adverse weather conditions, such as extreme cold with strong, gusty winds or extreme heat. In these situations, every extra amount of curtain 18 that can be devoted to the retention of the temperature controlled air within hangar 12 and the repulsion of ambient air contributes significantly to the maintenance of comfortable working conditions within hangar 10. In this respect, it should be noted also that the marginal side sections 32 of each sheet 26 and 28 further contribute to minimizing the open expanse of curtain 18 and should be as wide as permitted by the wingspan of the largest airplane contemplated for using hangar 10. The double thickness provision of curtain 18 as presented by sheets 26 and 28 is also important in minimizing the passage of air through curtain 18, and it is contemplated that where the cost is not prohibitive, sheets 26 and 28 may be constructed of a solid, homogeneous material as opposed to a woven fabric material such as canvas.

The sheets 26 and 28 are provided with an inner and outer series of depending, flexible closure flaps 44 and 46 which fill their corresponding openings 30 to provide limited entry therethrough. Each series of flaps 46 and 48 is secured to its corresponding sheet 26 and 28 along the seam 36, and the outer flaps 44 overlap the inner flaps 46 such that the slits presented between adjacent flaps 44 or 46 are covered to minimize the passage of air therethrough. If desired, the flaps 44 and 46 may be constructed of a transparent, plastic material to provide full and clear vision through curtain 18 and thereby minimize the possibility of accidents occuring during entry or exit of airplane 38.

Each of the individual flaps 44 and 46 is provided with variable ballast means in the form of a zippered pocket 48 at its lower extremity which is adapted to contain a granular weight material such as sand 50. Through the provision of a zipper 52 on each pocket 48, it is possible to add to or substract from the amount of sand 50 contained within pockets 48, thereby varying their effects as ballast for the flaps 44 and 46.

The curtain 18 is retained in place during pass-through of airplane 38 by the joint efforts of retaining and guiding structure 54 (FIG. 4) along the sides of curtain 18 and transverse stiffening means 56 across the curtain 18. The guiding and retaining structure 54 includes a split tube guide track 58 which extends vertically along each side of curtain 18 on hangar 10 and a following bead 60 formed in each outer extremity of the marginal sections 32 of sheets 26 and 28, each bead 60 being formed by sewing a flexible element between the sheets 26 and 28 as indicated in FIG. 4. The size of bead 60 is such that it will move longitudinally with ease within tube 58, yet may not be withdrawn from the latter through slit 62 in tube 58. The flexible nature of bead 60 permits curtain 18 to be rolled up during storage.

The transverse stiffening means 56 comprises a pair of inflated tubes 64 and 66 on the sheets 26 and 28 respectively which follow the outline of openings 30 a short distance above the upper extremities of the respective flaps 44 and 46. The tubes 64 and 66 decrease deflection of curtain 18 as a whole when airplane 38 passes through flaps 44 and 46, and thereby facilitate the movement of airplane 38 through flaps 44 and 46. Without tubes 64 and 66, the flaps 44 and 46 would tend to cling to the projecting parts of airplanes 38 since the whole of curtain 18 would bow in upon receiving the push from airplane 38. Tubes 64 and 66 provide a firm, rigid base from which flaps 44 and 46 can swing. Also, as clearly shown in FIG. 3, the tubes 64 and 66 project transversely outwardly from the curtain overhanging the regions within which the flaps 44 and 46 swing. The tubes 64 and 66 therefore can act as upper limits for the swinging flaps 64 and 66 as is obvious from FIG. 3. In this regard, it will be noted that in hangars where the distance from the entrance 12 to the rear of hangar 10 is such that airplane 38 is maintained closely adjacent curtain 18 when the airplane 38 is parked within hangar 10, the clinging problem may be accentuated. However, the stiffening tubes 64 and 66 discourage such clinging even in this situation, limiting upward swinging of flaps 44 and 46 and urging the same to their normal depending positions, aided by the ballast pockets 48. As shown in FIG. 5, valve fitting 68 is provided on each tube 64 and 68 for inflating or deflating the same.

In addition to the action of transverse stiffening tubes 64 and 68, clinging of the flaps 44 and 46 to the airplane 38 is also discouraged by individual, vertically extending stiffening air tubes 70 (FIG. 6) on the individual flaps 44 and 46. The air pressure in the individual tubes 70 is separate from that of transverse tubes 64 and 66, and tubes 70 may be totally independent of one another or have a common connecting conduit. In either event, a valve fitting (not shown) similar to fitting 68 may be provided for tubes 70 to permit regulation of the air pressure therewithin.

It should be apparent from the forgoing that my weather curtain assembly 16 is ideally suited for solving the problems heretofore experienced in maintaining continuity of working conditions within large enclosures such as airplane hangars, particularly in environments of extreme heat or cold. The overlapping flaps 44 and 46 do not allow the passage of air when door 14 is raised; only the forced entry of airplane 38 is permitted. Accordingly, even though the winds outside of hangar 10 may be cold and blustery, or hot and humid, door 14 may be raised and left open for substantial periods of time without fear of losing the comfortable working temperature within hangar 10. The airplane 38 may thus be moved through entrance 12 with all the deliberate care and speed which should be exercised when handling expensive, sophisticated equipment of this type.

Many of the flaps 44 and 46 remain undeflected during passage of airplane 38, and these provide a barrier to air seeking to escape from hangar 10 or the ambient air seeking to enter hangar 10. Moreover, the large expanse of solid, barrier area above flaps 44 and 46 and along the ends of openings 30 increases the ability of curtain 18 to prevent the passage of air substantially beyond that which could be obtained if flaps 44 and 46 extended the full height and width of curtain 18. In the event that the weather conditions existing at hangar 10 are moderate, the curtain 18 may be readily raised and stored in roll form on roll 24, although it may be necessary to first deflate tubes 64, 66, and 70.

Claims

Having thus described the invention what is claimed as new and desired to

1. A pass-through curtain for use on an enclosure across an entrance thereof, said curtain comprising:

a substantially solid, normally upper barrier portion precluding pass-through when the curtain is in use;

at least one series of side-by-side, elongated closure flaps depending from said upper portion along the lower extent of the latter,

said flaps having a line of hinging movement defined at their upper ends by their junction with the upper portion,

said hinge line extending transversely to said flaps for the full length of said series thereof; and

an elongated, overhanging, flap-restraining element extending along said hinge line closely adjacent the same for the full length thereof to stiffen the curtain and to resist excessive deflection of the flaps,

said element in its transverse dimension projecting outwardly for a distance from one side of the curtain beyond the flaps to provide a limit

2. A pass-through curtain as claimed in claim 1, wherein said element is generally cylindrical in cross-sectional configuration having its outermost arcuate periphery overlying the region within which the flaps

3. A pass-through curtain as claimed in claim 1, wherein said element

4. A pass-through curtain as claimed in claim 1, wherein is provided a second element on the opposite side of the curtain in alignment with the first-mentioned element for limiting swinging of the flaps in the opposite

5. A pass-through curtain as claimed in claim 4, wherein each of said elements comprises an inflatable tube having its outermost periphery overlying the respective regions within which the flaps swing during

6. A pass-through curtain as claimed in claim 5, wherein each of said flaps is provided with a weight at its lowermost end for augmenting the swing-limiting action of said tubes.