US2718036A - Airplane hangar type door - Google Patents

Description

Sept. 20, 1955 P. A. sTRoBl-:L ET A1. 2,718,036

AIRPLANE HANGAR TYPE DOOR 6 Sheets-Sheet l Filed Jan. 4. 1952 .HllHi!!!i1iminnniimilllllliill.

OO /n 1/ fors Pe/er A. S/fobe/ 4l/@2mn der H MCP/zee 5y /e/'r attorneys www Rear Daar Dow/7 Sept. 20, 1955 P. A. sTRoBEl. ET AL 2,718,036

AIRPLANE HANGAR TYPE DOOR Filed Jan. 4, 1952 6 Sheets-Sheel 2 A/exana'er/-X MCP/zee By /e/'r affomeys MMM Sept. 20, 1955 P. A. STROBEL ET AL 2,718,035

AIRPLANE HANGAR TYPE DooR Filed Jan. 4, 1952 6 Sheets-Sheet 3 6 /m/@n/ors Pe/er A. 5 1700/ A /exan der H MCP/2e@ 5 y fha/'r U/fomeys Sept. 20, 1955 P. A. STROBEL ET Al.

AIRPLANE HANGAR TYPE DOOR 6 Sheets-Sheet 4 /n Ven fors ,De/er A Sfmbe/ Ve/vander H McPhee 5y fha/'r afforneys Filed Jan. 4. 1952 A 2 m. l 1./ /l IIA Sept. 20, 1955 P. A. STROBEL ET AL AIRPLANE HANGAR TYPE DooR 6 Sheets-Sheet 5 Filed Jan. 4, 1952 /m/en/ors Pe/erA. Sfobe/ A/exdnder H Mc Phe@ By the/'r attorneys www United States Patent O AIRPLANE HANGAR TYPE DOOR Peter A. Strobel, New Rochelle, and Alexander H. McPhee, Plandome Heights, N. Y., assignors to Luria Engineering Corporation, New York, N. Y., a corporation of New Jersey Application January 4, 1952, Serial No. 265,038

3 Claims. (Cl. Ztl- 16) This invention relates to an airplane hangar and a hangar type door, and more particularly to doors for alert hangars for jet planes. It is essential that doors for alert hangars for military planes be so constructed that they can be opened quickly. This ability to open quickly is especially important when the planes are jet lighter planes. In such alert hangars where the jets have to be started while still in the hangar, it is necessary to have doors at both the rear and the front of the hangar and to open both doors before starting the plane. Because jet planes on the alert must be on their way in a matter of seconds after an alarm, it is imperative that the two doors open simultaneously and with minimum power. It is also desirable that the doors be light and compact and yet be full-width, full-opening doors. Heretofore it has been impossible to have such doors without providing a high roof. High roofs are expensive to build and maintain. They also cause a building to have a large volume to be heated. Furthermore, it is desirable that hangar buildings at airelds be as low as possible.

According to our invention the height of our alert hangar i is less than that of hangars heretofore known. Without sacrificing any clearance or any dimension of the fullopening, full-width of the door, a strong, light structure is provided which can be opened quickly and easily. It is characteristic of our invention that each door is pivoted on a horizontal axis and is a rigid hollow three-dimensional truss structure adapted to resist torsion and is operable from a single end despite its very long span. Furthermore, the two doors of each hangar unit are independent of the building and interconnected so as to be opened and closed from a single control station.

In the drawings:

Fig. l is a view in front elevation of part of a hangar made in accordance with our invention, the front door being shown closed.

Fig. 2 is a partly diagrammatic view in front elevation, with the front wall removed, of one pocket of the hangar of Fig. l, the front door being open andthe back door closed; the bracing of the inside face of the back door being omitted at the left of the ligure while the bracing for the roof of the door is shown for the full width of the door.

Fig. 3 is a view in vertical section through the front part of the hangar of Fig. l, taken on the line 3--3 of that ligure, showing the front door closed and its operating mechanism, the positions of some of the parts when the door is open being shown in dash lines.

Fig. 4 is a view in front elevation on an enlarged scale, showing the pedestal of Fig. 3 which operates the front door.

Fig. 5 is a view in side elevation of the pedestal of Fig. 4.

Fig. 6 is a schematic plan view of both pedestals of the front door and their relation to some of the associated parts.

` Fig. 7 is a view in vertical section through the entire 2,718,036 Patented Sept. 20, 1955 ICC hangar of Fig. l, on the line 3 3 of that figure, showing the front and rear doors and the single control station.

Fig. 8 is a diagrammatic side elevation of a form of our hangar control station modiied so as to be operable either mechanically or electrically, the parts being shown en-v gaged for electric operation but the wiring being omitted.

Fig. 9 is a View in side elevation of a modiiied pedestal for the electromechanical drive of Fig. 8.

Fig. l0 is a view in rear elevation of the crank mechanism of Fig. 9.

Fig. 1l is a diagrammatic view on an enlarged scale of one half of the drive unit of the electromechanical drive of Fig. 8.

F ig. 12 is afschematic view of the electric wiring of the electromechanical drive of Figs. 8-11, showing the general relation of the parts to the front and rear doors of the hangar.

Fig. 13 is an enlarged view in side elevation of the winds lass of Fig. 3.

There has arisen a demand on the military market for a hangar for jet tighter planes from which the planes can make a rapid start into the air. Such rapid start hangars are known as alert hangars. Instead of moving the plane out onto a runway and then starting the jets, the motive power of the plane is started while the plane is still in the hangar. In this way the plane can move out of the hangar under its own power and go directly into the air. The blast of burning gases from the jets requires that there be a rear door as well as a front door and that both be opened when the plane is to go out. The plane must be airborne in a matter of seconds and therefore the doors must be opened very rapidly after the alarm is given. On the other hand, the doors must be strong enough to withstand very strong winds, as these alert hangars are used in exposed places.

Alert hangers generally have a number of pockets or units for planes-one plane to each pocket. A building may contain half a dozen or more pockets. As shown in Figs. l and 2, each pocket may have a rigid .frame with columns 1 and roof rafters 2. The pocket .may be covered with galvanized steel roofing 3. Each column supports the roof structure. The roof structure has a peak or ridge 4 for each pocket, running from front to rear of the building, i. e., at right angles to the plane of the doors. This ridge is along the center line of the pocket and the roof slopes down to the eaves and valley 5 at each side of the pocket. Because alert hangars must be close to the runways it is essential that the building have an absolute minimum height. Such minimum height also minimizes the heating and maintenance costs, as previously mentioned. It also keeps down building costs.

In the example being shown and described, a vertical clearance of, say, twenty-three feet is required in the doorway or door opening 6. The eaves S of the hangar have to be kept as low as possible, commensurate with this fullwidth requirement. According to our invention `the eaves are almost down to the top of the door opening and the ridge of the door is at least partly nested in the peak or ridge 4 of the roof.

The doors which we use are hinged on a horizontal axis and when swung up are so related to the roof structure that the doorway is open for use by the airplanes for its full Width and full height. For example, the full-opening, full-width front door 7 is a single leaf or panel supported only at the ends by a cantilever construction pivoted on its own pedestal 8. These pedestals are independent of the frame of the building. In this way no load is added to the building frame by the doors.. The pedestals preferably are located outside the door opening 6 inside the hangar, i. e., outside the door clearance.

Hangar type doors have very long spans and generally must provide a clear span which also is high. They generally can withstand strong winds and with their long, high spans it is a problem to produce a door of suiicient strength with the light weight preferred for quick opening. We have invented a hangar type door that is so light and yet resistant to longitudinal torsion that its entire span can be raised or lowered by mechanism at a single end of the door. It is a rigid, hollow structure either prismatic or cylindrical in cross-section, or a combination of both. It is a structural system giving the properties of a tube. This rigid, tubular outline in crosssection can be considered as framed in space, i. e., in three dimensions, without any points of attachment intermediate its ends. In the example shown and described the door is trussed both longitudinally and in cross-section. A trussed structure is a planar structure composed of members connected at their ends in such manner that the areas bounded by the members are triangles. The framing is a triangular prism in cross-section but a curvilinear exterior could be afiixed to the framing. Each face of this three-dimensional truss structure is joined to its neighbors along its longitudinal edges and each face is trussed separately in its own plane and is planar. When closed the door shown has a straight, vertical inner face and a longitudinal ridge 9 facing outwardly at a point midway between the top and bottom of the door (see Fig. 3). In a typical door the depth in cross-section from the ridge to the inner face may be five feet, while the length of the door may be sixty-four feet. We propose to operate the door from one end only, and the door has a longitudinal truss construction which enables it to resist torsion arising from driving the door from a single end.

As can be seen in Figs. l and 2, the ridge 9 on the outside of the door does not extend the full width of the door but is cut oif at the ends. This leaves a bevelled end 10 at each end of the door and a bevelled corner 63 at each upper corner. The upper corners of the door opening in the hangar can be correspondingly bevelled at 64 without interfering with passage of planes. This can be seen from the outside of the closed front door of Fig. 1 and in cross-section in the open front door of Fig. 2. AThe outside of the door is built similarly to a roof, having girts 11 running parallel to the ridge 9 at points intermediate the ridge and the eave beams 12 (see Fig. 3). The ridge 9 is connected to the eave beams 12 by rafters 13 and by diagonal end rafters 14 defining the edges of the bevelled end panels 10. The whole outside of the door can be covered by corrugated steel siding 15 which is overlapped at the ridge to form a weatherstrip 16 (see Fig. 3). The inside face of each door is shown with the framing uncovered. At the eave beam which is'in contact with the ground when the door is closed, a rubber weatherstrip 18 is provided to give a weathertight closure. Diagonal tie rods 19 are used between the rafters, these being shown in solid lines in Fig. 2 in the closed rear door of the hangar.

The flat, inner face of the door may be composed of angle iron chords 21 extending directly across from one eave beam 12 to the other, together with diagonal tie rods 22 (see the right half of the rear door in Fig. 2). Diagonal braces from the chords 21 to the roof raiters 13 complete the intermediate rafter truss structure.

The eave beams 12 preferably do not extend toward the ends beyond the point where the bevelled end panels 10 begin. Instead, heavier beams 23 are provided extending beyond the ends of the door to the cantilever structure on the pedestals carrying the door. In addition, as can be seen in Fig. 2, heavy braces 24 can be provided meeting the beams 23 at the ends of the door and extending diagonally to the main cantilever beam 33, hereinafter mentioned. The front door 7 can have a small door 25 in it for personnel to pass through. In section the door has three truss structures in triangular arrangement tied together, producing the tubular effect above mentioned. By these means torsion applied at one end of the door to elevate or lower it is transmitted to the other end without twisting. Therefore it is necessary to supply operating mechanism only to one end of the door despite the great length of the structure.

Each hangar door is supported at each end on one of the aforementioned pedestals independently of the frame of the building. The pedestals at the two ends of the front door can be seen in plan in Fig. 6. The pedestal on which power is applied to move the door can be seen in elevation in Figs. 3-5. Each pedestal is a steel truss frame securely anchored to the oor, consisting of a base member 26, a pair of vertical posts 27, and a pair of braces 28 running from the end of the base nearest the door to a position joining the vertical posts 27 at the top. Each post and brace is spaced from the companion post and brace. On the top of each post is a pillow block 29. The pedestal is strengthened by bracing members 31 extending between each post and its companion angle brace 2S. Supported between the two pillow blocks 29 are trunnions 30 on the cantilever construction which carries the door. As shown in Figs. 4 and 5, there are two side plates 32 on the axle formed by the trunnions 30 and welded to those plates are some of the beams of the cantilever. As viewed in Fig. 3, there is a main beam 33 extending horizontally to the middle of each end angle iron chord 21 of the door and past the plates 32 toward the rear of the hangar. A vertical channel iron extends upwardly to main connecting plates 35 of the cantilever brace 34. On the rear end of the main beam 33 is a counterweight 37. A supplemental brace 36 extends from this counterweight 37 through the main connecting plates 35 to the edge of the door which is uppermost when the door is closed. It will be noted that the pivoted trunnion mounting is opposite the midpoint of the door when closed, as is the counterweight, and that the main connecting plates 35 are between that midpoint and the upper edge of the door but preferably above the counterweight. A secondary brace 38 goes from the main connecting plates 35 to the midpoint of the door where it connects up with the rst-mentioned horizontal channel iron brace 34 coming from the trunnion mounting. In Fig. 3 these parts are shown in solid lines in position when the door is closed and in dotted lines in the position some of them occupy when the door is open. The mechanism so far described is duplicated at each side of the hangar pocket, i. e., at each end of the door, and results in the doors being statically balanced in all positions.

As already stated, it is necessary to be able to open these doors in a matter of seconds and we find this can be accomplished with the door and cantilever mounting above described by providing the following operating mechanism at only one end of the door. In the drawings we have shown the mechanism at the left side of the hangar, as viewed from the front in Fig. 2. We provide a single mechanism which can be operated at one point to operate both doors of a hangar pocket. The operation is achieved by applying power to a single member, and we also provide a single brake mechanism which similarly applies the brake for both doors. Means are also provided by means of which either door can be disconnected from the common positive drive unit. This common operating or control point for the two doors is shown and described located midway between the front and rear of the hangar pocket, and it has as its basic unit a handwheel or windlass 40. This windlass can be operated manually. ln view of the fact that the doors are each statically balanced, and in view of the nature of the mechanism between the handwheel and the doors, it is only necessary to accelerate or decelerate the doors to move them from one position to the other.

The mechanism for the doors will be described with reference to the front door 7 only but it will be understood that similar mechanism operates the rear door 17. rl`he operating mechanism is essentially a crank mechanism connected to the door structure in such a way as to rotate through 180 in moving the door from open to closed position, or vice versa. There is a main operating shaft 41 lying horizontally between the windlass and the pedestal, whose rotation transmits t-o the pedestal the power applied by the operator. The elements between the shaft and windlass will be described later. The main operating shaft 41 is shown equipped with universal joints 43 located at appropriate points. At the pedestal end this main shaft rotates an input shaft 44 belonging to a Worml gear speed reducer 45 mounted on the pedestal (see Fig. 5). On the output shaft of this speed reducer is a small sprocket 46 which through a chain 47 drives a large sprocket 48 pivotally carried on the angle brace 28 of the pedestal (see Figs. 4 and 5). This large sprocket 48 is carried on a shaft 49 extending from the brace 28 on one side of the pedestal' to the brace on the opposite side. It will be seen from Figs. 3, 4, 5 and 6 that the sprocket is adjacent the brace nearest the wall of the hangar. On the opposite end of the shaft is a crank 50 whose free end 51 is pivotally attached to a tubular adjustable connecting rod 52 by anti-friction bearings 53. This connecting rod is fastened at its other end to a pivot pin 54. This pin carries channel irons 4Z attached to a supporter rocker arm 55 rigidlyv ar ranged with relation to the main cantilever beam 33. The crank 50 is so arranged that when the door is eithercompletely closed or completely open, i. e., in its terminal position, the connecting rod and crank are on dead center. As the door starts to move and the crank rotates away from dead center, the moment arm to the connecting rod increases, gradually reaching maximum after having travelled about 90. From this point on, i. e., from the point of maximum moment arm, the arm again decreases, gradually reaching zero at dead center when the door reaches its opposite terminal position. With this construction a rotation of the windlass results in torque being resolved into force but it is the torque that is applied, not the force. The arrangement described results in a cyclic operation which automatically limits the movement of the door to a predetermined angular rotation. Thus continued rotation of the crank arm in the same direction would merely reverse the direction of movement of the door and return it to its original position. It wil'l be seen that with this construction it is impossible for the door to be opened beyond its 90. This is a desirable thing because any swinging of the door beyond that point might bring it down on top of a plane in the hangar. It will be seen that maximum power and maximum speed are obtained at the two points where desired so as to get rapid opening of a very heavy door with the minimum power required.

We will now describe the construction of the drive unit for the two main operating shafts 41. As already stated, this station or unit is located in the center of the hangar, midway between the two hangar doors. The main operating shafts 41 are brought together on opp'osite sides of the windlass. At this point they are connected to what may be termed the output shafts 56 of a bevel gear drive 57. The axes of these two shafts are 90 from the axis of the operating drive and it will be noted that in this way we are able to operate both doors from a common windlass wheel. The clutch is indicated in Fig. 13 by the reference character 62. Integral with this windlass wheel is a brake drum 59 which is engaged by a manually applied brake lever 60 through an adjustable toggle mechanism 61. This enables the operator to slow down the movement of the doors or to hold the doors in any desired position. This brake mechanism can be arranged to be self-locking if desired.

In order to permit disconnection of one of the doors, the connection between each main drive shaft 58 and its output shaft of the bevel gear drive is made by a manually operated clutch 62.

It will be noted that the load provided by these doors is a very high inertia load. T o enable this door to be operated by hand power we have not only provided a crank mechanism applied directly to the rigid frame of the door cantilever at a point above the horizontal when the door is closed, but to assist the starting of movements we have provided a worm gear or other device having high mechanical advantage.

it is of primary importance that the power required to elevate the doors of the alert hangar be kept as low as possible. The balanced door structure assists in this direction, but this alone might not always be effective in practical operation, for the following reason. It is frequently necessary to open the hangar doors in windy weather, and in view of the very large surface of the doors, the amount of power required to elevate one of them has heretofore been great when the wind was blowing against the door. We have discovered that this adverse factor can be done away with entirely in our hangars. By opening both front and rear doors simultaneously from a single control station so arranged that there is a positive drive connection through from one door to the other, we have found that the increased resistance of one door due to the wind pressure is cornpletely offset by a vacuum created on the opposite door by that same wind. Thus the door which has the vac-- uum requires so much less power to operate it that the net total power required for the two doors is no more than would be required if no wind were blowing. Therefore the power requirements to lift the two doors of our hangar can be based on a no wind situation rather than a high wind situation.

In Figs. 8-12 we have illustrated a modified embodiment of the invention in which the drive unit can be driven electrically or by hand. The mechanism is so arranged that if desired one door can be operated alone or can be operated electrically while the other door is being operated by hand. ln embodiments where both electrical and mechanical forms of operation are available the drive unit at the center of the hangar has separate electrical drive mechanism 66 for each door, a clutch 67 for each door adapted to shift the unit between mechanical and electrical drive, and a single manual drive 68 adapted to operate one or both doors as desired. The manual drive is unchanged from the embodiment of Figs. 1-7 but a slightly different form of clutch is supplied between the drive mechanism and the drive shafts than was used in the purely mechanical embodiment. The braking means 69 for the mechanical drive is also unchanged in principle, being self-locking and a lever type of brake with a pawl (not shown) to hold the brake until released by the operator. There are individual electrical drives for the two doors. The electric motors themselves contain brakes, being a hoist type of motor. These integral brakes are mechanically applied and electrically released.

As shown in Fig. ll, there is an individual electric motor 70 for a door, and a silent chain drive 71 to a worm reduction gear 72. This motor reduction gear is on a horizontal shaft 73 carrying a drive sprocket wheel 74. This sprocket wheel drives a somewhat larger sprocket 76 on the main drive shaft 41 by means of a chain 75. The clutch for manual operation of the door is located between the sprocket and the bevel drive 57. The driven sprocket is tight on the drive shaft 41 and therefore turns with the drive shaft when the clutch for manual operation is in engaging position. We therefore provide the following parts in order that the electric drive reduction gear 72 and motor 70 may not be driven from the drive shaft 41 when the door is being manually operated.

The small drive sprocket 74 on the worm gear shaft 73 is free to rotate on that shaft. Part of the electric drive clutch 67, namely, the clutch plate 77, is unitary with the shaft. The companion clutch plate 78 is slidably mounted on the shaft. When the two plates 77, 78 are in engagement with each other the driving power of the electric motor 70 and reduction gear 72 will be transmitted to the drive shaft 41.. When the two clutch plates are disengaged, any rotation of the driven sprocket 76 will be idle and will not be transmitted to the worm gear and electric motor.

The electric drive clutch 67 isy manipulated by means of a hand lever which controls both the manual clutch 62 and the electric drive clutch 67. For this purpose we provide a vertical lever 79 pivoted on a block 80 at the bottom of the pedestal of the drive unit (see Fig. 1l). Lateral movement of the upper end of the lever engages and disengages the clutch for the electric drive. The connection between this clutch control lever and the clutch for the manual drive is as follows. The movable clutch plate 81 of the manual clutch is slidably mounted on the drive shaft and'. rotates with the shaft. lt has the usual outer sleeve 82 which does not rotate but is fixed to the movable clutch plate. To this outer sleeve 32 is pivoted a vertical crank arm 83 pivoted at its center on a bracket 84 carried by a vertical post 85 of the drive unit. The lower end 86 of this crank 83 extends below the bracket to a point where it is pivoted to one end of a horizontal link 87 extending laterally to the upper part of the clutch control lever 79. These linkages are so arranged that when the clutch control lever is moved to engage the clutch plates of the electrical drive, the clutch plates of the manual drive are disengaged, and vice versa. A universal joint 42 can be used between the manual drive and the drive shaft going to the door.

The basic electrical circuit for operating the two doors is shown schematically in Fig. 12. The electric operation is controlled from two push button stations 88, 89 located adjacent each other, preferably close to the windlass 40. Each push button station has three buttons, an up button to raise the door, a down button to bring the door down, and a stop button. These, in connection with magnetic reversing controllers 90, give the necessary basic controls to t in with the manual operation. Thus, if the operator presses the two up buttons and one door is already open, that door will remain in this position. If the door is partially open it will inish the opening operation. In this way the doors will automatically go into phase with each other at the end of the operation even if they were not in phase before. If the two doors are to be operated manually the operator will have to observe the condition of the doors and bring them into phase with each other before operating them together.

Limit switches are provided to stop the doors in fully open or closed position when being operated electrically. These comprise two limit switches 91, 92 for each door, located on the driving pedestal carrying the crank 50 and connecting rod 52 for the door. As can be seen in Figs. 9 and l0, two levers 93, 94 are fixed on the shaft about which the crank 50 revolves. These levers 93, 94 are set say 90 apart. When the crank is at its dead center position with relation to the connecting rod, one or other of these arms will engage an operating arm 95 of one of the limit switches 91, 92 mounted on the frame of the pedestal. When a limit switch is thus engaged it serves to break the electric circuit to the motor for the power, the connections being through the magnetic reversing controller.

We also provide means adapted to break the electric circuits to the electric motors when the doors are to be operated manually. To this end a switch 96 is mounted Ill) on the frame of tthe drive unit near the horizontal link 87 attached to each clutch control lever 79 (see Fig. 8).l The clutch control lever has a bevelled end 97 extending` beyond its connection with its crank lever 79 and that bevelled end engages the operating arm of the limitA switch. The switches are so located that when the clutch control lever is moved toward the center of the drive unit engaging thev electric drive clutch, the limit switch is pushed to closed position and it is possible for the motor to receive electric current. The limit switch is normally open. As soon as the clutch lever moves to the position for manual operation, the operating arm of the switch is released and opens the switch and the electric circuit is cut off from the motor. These limit switches can be considered as interlocks on the clutch to prevent operation of the motor when the clutch is engaged for manual operation. We also provide the usual 3-pole, fusable safety switch boxes 98 with levers 99 to open and close the circuit when it is desired to inspect or replace fuses.

It will be seen that in addition to the special advantages arising from using our door in the hangar described, the door can be used in many other types of buildings where long, free spans are required.

What we claim is:

1. A hangar type door comprising a rigid, hollow structure having three faces and in the form of a longitudinal prism, the door being trussed in each of its longitudinal faces against longitudinal torsion from one end of the door, two pedestals standing on the floor, a framework pivotally supporting the door on the pedestals on a horizontal axis at each end, and counterweights onA the framework to balance the door, in combination with operating mechanism attached to only one end of the door to open and close same.

2. A. hangar type door comprising a hollow structure adapted to be pivotally supported at its ends on a horizontal axis, the structure being a triangular prism on a horizontal axis, each longitudinal face thereof being separately trussed in its own plane and united at its edges to the other faces of the prism; whereby the door resists longitudinal torsion and can be opened or closed by application of power at one end of the door.

3. A hangar type door according to claim 2 in which there are interior trusses in cross-sectional planes in effect dividing the door into cells; whereby the cross-sectional planes force the trusses in the three faces to act together and the door is further strengthened against longitudinal torsion.

References Cited in the file of this patent UNITED STATES PATENTS 1,908,659 Cross May 9, 1933 2,043,473 Eager et al. June 9, 1936 1,402,295V Rosenberg June 18, 1946 2,476,755 Morgan July 19, 1949 2,532,456 Merritt Dec. 5, 1950 2,590,464 Raymond Mar. 25, 1952 2,610,366 McKee et al Sept. 16, 1952 FOREIGN PATENTS 810,725 France Jan. 6, 1937 OTHER REFERENCES Engineering News-Record, article entitled Bascule Door for Airship Hangars Built in France, April 1922, vol. 88, No. 17, page 690.

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