US 2383559 A
Description (OCR text may contain errors)
Aug 28, 1 945. H. C. PARKER AIRPLANE LUNCHING DEVICE AND Filed Jan. 17, 1 942 flllnvl'll vx Tm l l l l l l l l l l l l l ,l l
Patented Aug. 28, 1945 UNITED .STATES PATENT v(1F-FICE 'AIRPLAE L` UNCHINGDEVICEAND L CARRIER :"Henry CfParker, Washingtom-D; C. Application-January 17, 1942,'Seral'1No. 427,196 f firoljaims; (elfen-:63)
invention relatestoairplanelaunching device `and carrier; and it` comprises a-device for launching airplanes by means of a runway having a length which is a fractionof that normally re-y quired, said runway beingat4 leastpartly enclosed by a wind tunnel supplied with means lfor pijopellingairv at a high velocity-through said tunnel 'duringthe take-off of an airplane,I wherebythe plane is propelled at a rapidly increasing rate'throughthetunnel and to the endl ofV the runway, said r way advantageously sloping upwardly at leastatmitstakeloi end` The invention,"l also includes an air-craft` carrier equipped with?` the described launching device, saidf carrier comprising an upperV landing decky anda wind tunnel" provided with-a' blowerbeneath said deck, theiloor of said 'wind tunnel( forming a takevoi rnway,'the exit` to said wind tunnel beingat the 'forward end'of the carrier, the runway at thisend being advantageously extended for-some distance beyond the landing -deck and sloping upwardly to a point whichmay lie Asubstantially at the level of the"l'anding`"deck; said'wind `tunnel being equipped 'With elevators or the like serving to 'placeairpla'nes in vpuosition for'take-oif 4at al pointinfront ofsail` blower; all asmoreffully hereinaftertsetforth and as claimed.
Tlieino'd'ernairplanelre'quires a runway of a length which depends upon the lWeight fthe;
plane and partly upon its' speed. In the case of heavy transport. planes andbornbers'for-"example," Arunways o fjwellover 1'00' y'ar'ds are cornmonly required; This"g1"eatly limits 'the usefulness lof thistype of' plane since runways'ofthis lengtharefcostly to build` Moreover such run' lways are 1eas'yftospotfrom the'air and'diflicult c to camouflagefWhich-ffmakes them a'militaryjliability. In addition, Ithe necessity for lon'grunways for heavy planes prevents suchplanes from being used on vair-craft carriers.` For Vthis reason theplanes used 'on carrierslcannot usually-'cope with land based planes. f 4 .Many "attempts .have '-beenfimade to 'fdevise launching devices for planes which would'dispense with the usual runway. `These have Mineluded variousv types of rotatingftowers :and catapults but, while some success hasbeenihad with the latter, it has been found impossible -to 4use these devceswith heavyplanes.` Y A disadvantage of these launching devicesis that the :planes used must be specially' adapted tothe launching ldev1ce.'j i.
Thepresent invention is`be1ie'vd to`furnisha solution `for thisr'problem'"byL the 'f use f a`wnd tunnerffornumbing-purposes me wind pro;
duced in the windvtunnelV acts like a tail Wind, tending-to-propel the'airplane at a rate which is equaltothe wind velocity plusthe normal ve- ,locty of `the plane. -Moreover when the plane propellers are ffgunned. just prior to the take off, the air fbecomes compressed in the tunnel backl of the plane, dueto' thefaction of the pro-l pellers,` andV this compressed air assists in the take .o if, -this effect being added to the leffect produced by the tunnel blowers.- fA considerable advantage is gained evenby starting the plane in a tunnel with aiclosedl` end Awithout the use of blowers,'-since `the air compressed behind the E plane blows outer-the `tunnel with the plane, thus Aserving asa tail wind Moreover, the surface offered toa tail fwind, when a plane is on the runway, is greater than when iiying; hence a shorter time is-required `for-the plane to acquire wind velocity.
yIn order to reducethe requiredV length. of runway -by 'one-half, itis necessaryyto produce a Wind velocity in the tunnel which'is approxi- :mately equal to-the take oi `speed Vof the plane. `rBut `owing to-the-advantage'gained by the compression produced by the planef'propellers, the` increased. speed produced by the'use of a tunnel is `usually somewhatlgreater than Vthe'wind velocity-in the tunnel. If the'tunnel is capable lof .kproducingfawindvelocity which is'higher than 'the takeol' speed ofthe planethe lengthof the runway can be still further'shortened;
-I have found that it' is possible to combine the usual windtunnel with anair-compression chamvber in suchmannerthat the power required to "supply air vto-the wind tunnel may be greatly reduced. YAIfa-large'compression cham-ber'is provided back of thefplane'position;separated from the wind tunnel by means of doors and if the pressure inl-this` chamber is built up to a suin- "cient degree, Which-can be accomplished over a period of time-evenffby means 4of a small blower unit operating in -a'=,correspondingly small air ductfthe doors can be openedl at the moment of take olf andthe` resultant rush of air from the chamber `Wi-ll, propel the plane as eiectively as in the case of a much largerblower operating without Athe use-of -fa compressionr chamber. Of course, -whenf a 4small blower is used, the time re- .qui-red tolbuild up .itheirequired pressure-in the compressionf chamber 'may' loe-:unduly prolonged. But if planes ldo not need to be launched in rapid succession, this is -of no particular disadvantage. If it is necessary to launchplanes `with great ra- "carriers, for e'iample, a large blower or several operating in series must be used but even in this case it is usually possible to employ a relatively smaller compression chamber of such size that Substantially full pressure will be built up within a period corresponding to the period' between launchings. The air chamber doors can then be opened and closed rapidly. For maximum launching speed, however, it is necessary to provide a blower of sufficient size to produce a continuous wind of .the desired velocity.l In this case planes can be launched .as rapidly as they can be placed in position in front of the blower. With direction of the wind changes, although this would be possible with a portable or rotatable design, for example with a wind tunnel mounted on a turn table.
My invention can be explained in somewhat greater detail by reference to the accompanying drawing which shows, more or less diagrammatically, how my launching device can be embodied in the air-craft carrier of this invention. In this showing, l
several airplane elevators in successive use, the
tends to force a plane downwardly rather than` upwardly. The tunnel wind therefore tends to hold the plane against the runway. In the ab sence of a tail wind it would, of course, be dan-y gerous to employ an enclosed runway. The
front end of the runway usually `extendsrbeyond the wind tunnel land is usually sloped upwardly.
Fig. 1 is a vertical sectional view through an aircraft carrier provided with a wind tunnel, taken along the line I-I of Fig. 2,
Fig. 2Ais a horizontal section, taken along the line 2-2 Of Fig. 1,
that Aof Fig. 1, but showing a modication.
In thedrawing like parts are designated by like reference numerals. Referring to Fig. 1, the landing deck of the air-craft carrier is shown at 2. Beneath this deck and at any suitable location'in the body of the ship a Wind tunnel I is This upward slope also tends to hold theplane against the runway by the tail wind. The princi? pal danger is that it will twist in the tunnel owing to a non-uniformwind velocity. This tendency can be overcome by the use ofrails on. either side of a rear wheel. f l l Another possible danger is that the plane will tend to tip over on its nose. But this can be prerails to prevent twisting of the plane. If these safety provisions are` made, launching from a wind tunnel is even safer than from the exposed' ample, and the planes can be rolled throughA the hangar to take off position in the tunnel. In
the case of underground hangars, the tunnel may itself be underground, the take off end of Ithev runway alone rising to the surfacev of the ground. Needless to say this take off end of the runway provided. If desired the space between the landing deck and the wind tunnel may be used for airplane storage or the tunnel may be installed directly below the landing deck.
The air pressure for the'wind tunnel is supplied by means of a large fan 3, which is located in the rear of anair compression chamber 4. The fan is located in a duct 5v which divides into two sub-ducts 6, 6 whichlead to the exterior of the carrier, preferably vbeing connected at their ends to two air scoops I, 1. The air collected in these scoops is blown by the fan into the air compression chamber which is normally closed except for the duct 3. The air compression cham- 40 ber is connected to the Wind tunnel by means of in front of the doors 8. vented by providing 'a small wheel or skid atY the top-most point of the rudder, vadapted to; skid along .the top ofthe tunnel between two,
" two sliding doors 8 which may be opened quickly at the moment of take oi.
VPlanes ID are lifted or lowered into the wind tunnel by means of an elevator 9 at' a point just n The elevator shaft I4 y should be air sealedA and the doors I3, which close the shaft opening into the Wind tunnel are preferably opened automatically as the Aairplane is raised into the tunnel. The motors of the planes are opened wide or gunned as the elevator places them in take-off position. The plane motors tend to drive the air backwardly against the doors 8 and this produces some compression at this point which assists in the take off. But at the moment of take off the doors 8 are opened quickly and the 69,-l idly down the wind tunnel 'along the rails l5 and could be readily concealed from the air, since it would constitute merely a short hole in the ground. By this means the entire air eld would be invisible from the air.
It should be noted that, owing to the highveas it leaves the runway is definitely propelled-into the air at some distance above the ground, it is not necessary that the take cfr" be made into s the wind. In other words, it-is not -necessary to change the direction of thewind tunnel as the out through the opening II on to an upwardly sloping flight deck I2 which may` protrude in front of the carrier. By they time it reaches the end of the run Way its speed is sullcient for the vtake-o The cross section of the win'd tunnel may conform to some extent to the contour of the planes, asshown in' Fig. 3. It is obvious, of course, that considerable clearance should be provided a1- though, if the walls of the tunnel are smooth, no
, damage would be done even if the wings or body of the plane should lightly brush the walls. These wallscan be made of ply wood or steel and can be readily czhangedy to nt different plane models, g
separate air ducts. Or if a single air duct is usedy several fans operating in series can be placed in this duct as shown in Fig. 4. In. any case the fans employed are advantageously powerfull enough to produce `an air `velocity throughthe wind tunnel, with the doors open, which atleast approximates the takeoff speed of the plane.
In the modification of Fig. 4, the-JQJI*,c0111-- pression chamber is eliminated and two fansoperating inseries are mountedinan extension of the wind tunnel which is-of circular cross section. Invthis modification the doors 8 may be left open during launching operations. Two or more elevators are employed to place the planes in take off position and this enables a large number of planes to take oft in a minimum of time. The
elevators are, of course, operated alternately..
The wheels of the planes in this modification are advantageously locked to the floors of the elevators up to the moment of take off in order to prevent them from being blown over as they are raised into position. In this modification the wind tunnel starts below decks and slopes upwardly. Its upward slope may be such that the run way reaches the level of the landing deck at approximately the bow of the ship or the run way may be extended for a slight distance forward as shown in the drawing, The fans 3 in this modification are somewhat more powerful than those required in the modiiication shown in Figs. 1 and 2, since the initial inpulse given to the plane by the stored compressed air is not produced.
The present invention appears to offer a solution for the problem of using large bombers on aircraft carriers, since the length of runway required for take off can be reduced by at least one-half. The entire surface of the upper deck is available for landing and anti-air or other defenses. This is an important advantage since separate crews can be trained for landing and taking oi operations. There is no interference between these operations, since the planes making landings come in from the rear while those taking oif go out from the front of the carrier. Of course signals can be arranged, visible on the upper deck, which indicate that a plane is about to take off.
While I have described what yI consider to be the best modifications of this invention, it is evident, of course, `that many modifications can be made in the specific structures described without departing from the purview of this invention. Thus, it is possible to include two or more take off wind tunnels in the same carrier if desired. The take 01T deck extending in front of the carrier can be omitted and, in the-case of a long carrier, the exit of the tunnel can be made flush with the landing deck at a point just in front of the bow of the ship. In this case the wind tunnel as a whole can be sloped upwardly at a constant slope, as in Fig. 4, or with the slope increasing as the deck is reached. If desired the landing deck can be sloped upwardly above the exit of the tunnel. The run way can be curved upwardly if desired, for example in the shape of a parabola. The blowers supplying air to the wind tunnel may be driven by any suitable means. A powerful gasoline motor is advantageous when electricity is not available. To obtain the highest wind velocities the blowers should be larger than ythe tunnel, the ducts in which they are installed tapering down to lit the tunnel, as shown in Fig. 4. In special cases it is even possible to launch `airplanes without `the use of a blower. This canbe accomplished bythe use of large tanks of compressed air which can be Aused to supply pressure to the compression chamber just before the doors are opened for the take off. It is also possible to compress the air in the compression chamber by means of any large capacity pump.' At the start of the takeoff the rear aps' of the plane can be loweredin order to expose the maximum surface to the tail wind, these napsv being straightened as the plane leaves the tunnel. OtherV modications of this invention,
whichfall Within the scope of the followingl claims, will be immediately evident to those skilled in the art.
What I claim is:
1. In combination, an air-craft carrier, supplied with airplanes and having an upper landing deck, and a wind tunnel sufnciently large incross section to permit passage of an airplane therethrough, said wind tunnel being at least partly below said landing deck and being provided with a take oir runway forming the bottom of the tunnel, and means associated with the wind tunnel for supplying a tail wind to said airplanes during take off. y
2. The combination of claim l in which the wind tunnel slopes upwardly from its startingr end to a point substantially at the height of the landing deck.
3. An air-craft carrier supplied with airplanes in combination with a take off runway starting below decks, a wind tunnel enclosing at least the starting end of said runway, means for supplying air to said tunnel atthe starting end of said runway at a velocity at least approximating the take off speed of said airplanes and means for introducing airplanes into said wind tunnel at a point in advance of said air supply means.
4. An airplane launching device which comprises in combination a take-oil? runway, a wind tunnel having a forward take-oir and a rear starting end, enclosing at least the starting end of said runway and sufficiently large in cross section to permit passage of an airplane therethrough and means positioned at the starting end of said tunnel for supplying air under pressure in the rear of airplanes during the take-off of airplanes, said wind tunnel and runway being sufficiently long to enable said airplanes to acquire take-off speed before reaching the end of said runway.
5. The launching device of claim 4 wherein said air supplying means includes an air compression chamber having a cross section larger than that of said wind tunnel.
6. The launching device of claim 4 wherein said air supplying means includes a blower mounted in an air duct communicating with a compression chamber having a cross section larger than that of said wind tunnel.
7. An air-craft carrier supplied with airplanes comprising an upper landing deck, a take off.
airplanes in said wind tunnel at a point in lfront of said aixsupplying means.
. 8. In combination, a wind tunnel having a cross section suiciently large to permit passage of any airplane therethrough, an airplane take oi runway forming the bottom of said Wind tunnel, an air compression chamber and means for releasing the compressed air into said tunnel in the rear of an airplane at the moment of take off.
9. In combination, an airplane take-off runway anda Wind tunnel having a forward take-off end and a rear starting end and being suiciently large in cross section to permit passage of'an airplane therethrough, the runway forming the bottom of the wind tunnel, and means positioned at the starting end of said tunnel for supplying a tail wind at high velocity to an airplane during the take off of said airplane from said tunnel.
forming av continuation ofvsaid. wind tunnel;
means for supplying yairunder pressure to said compression chamber, means for releasing said air underlcompre'ssion into the'starting end of said Wind tunnel and means for operating said releasingmeansat the moment of take-cin 'f HENRY C. PARKER.