US2469659A - Tethering device for airplanes - Google Patents

Description

J. MARTIN TETHERING DEVICE FOR 'AIRPLANES May 10, 1949.

3 Sheets-Sheet 1 Filed July 31, 1945 Irma/0r May 10, 1949- .1. MARTIN TETH ERING DEVICE FOR AIRPLANE S- 5 Sheets-Sheet 2 Filed July 21, 1945 J. MARTIN TETHERING DEVICE FOR AIRPLANES May 10, 1949.

Filed- July 21, 1945 3 Sheets-Sheet 3 25 I'm/017 02 mam ir/w caV/o/myw.

UNITED STAT iQ'FFLCE TETHERING DEVICE FORAIRPLANES James Martin, Higher Denham, near Uxbridge, England Application July 21, 1945, Serial No. 606357 In Great Britain August 7, 1944 5 Claims. (Cl.-2441l5) l .2 .'This :invention relates? to tethering an aeroof .areoplanershowing"diagrammatically hOw -it TL'PIBJIELOXI the groundwhilst the engine is being is tethered according to-this invention.

run for. testing or tuni purposes or during Pie- Fig. 2 is a perspective view of a cage for anchorir-zliminary running-up of the engine preparatory ing in the ground andv provided with a socket oqthe aeroplane taking off from an aerodrome or 5 tadaptedto receive the base pillar.

thenplace. It is the usual practice when test- Fig. 3 is a'partrsectlonal .elevationvshowingsan s zing: or *runningmprthe engine of an areoplane ...alternative type of socket and also the base pillar 112071312468 wooden or-..other checks in front of the and swivel plateforzthe tethering cables.

landing wheels of the aeroplane in order to pre- Fig. i is a perspective view ofsone of the undervent it from moving onthe ground owing to the i carriagelanding wheelsshowing how the tether- :wthrust. produced by rotation of the airscrew or ing cable ma b attached to its axle.

nairscrews. Owing to the steady increase of en- Fig, 5 is a part sectional planshowingythefors n power and t0 the reased thrust produced ward end of the tethering cable securedto a by variable pitch and contra-rotating airscrews, swivel plate on the end of-ztheiaxle'of'anvunder- ;.this method is no longer satisfactory and this ap- 5 carriage landing wheel.

v-splies more parti ul y t oplanes of the high "Fig. 6 is a perspective view showing in detail xt'spe fighter type. It is found that there is an ;.the base pillar withiconnections for thetwo :forszincreasinggtendencey for the aeroplane to jump 1ward1y extending tethering-cablesand the upg-thechocks when the engine is n p 3 wardly extending cable for connection to the rear .thing like full throttle or maximum revolutions, end of the fuselage'of the aeroplane and includwith a conseq en n r of damage to the aer ing .means' for adjusting: the effective length of :-plane and of injury to the pilot or tester in the .the upwardly extending cdb1e,,and

aeroplane and other mechanics or onlookers in Fi 7 i a detail showing an alternative ad- .rgthe1neighborhcod. The object of this invention justing means for varying theeffective length ;-is toprovide a more reliable and positive method f the upwardlyextending cable.

::r.0f;:anchoring 0r et gi aeroplane 011 an -Referring to Fig. 1 of the drawings the aero- -:aaerodrome or other place. plane l is tethered? by? two tethering cables. 2 izAccording, to this invention a single tetherin secured at their forward endsto the axler-en'ds .memberis securely :ranchored and fixed in t of the landin wheels 3 of the undercarriage :iaerodrome; runway,- t sting shed or ot er p a 36 legs 4. The-dot anddashlines indicate alternaa swivelling connection is provided on the tethertivepositionsfor tetheringcables 2a which:may fling member Securing 011601 more Cables .be secured tothe undercarriage legs 4 or even sadapted to be connected to forward parts of the higher up close tdth i m; of attachmentqto e opl ne to take the-forward thrust and a furthe wingsof the aeroplane. :The other. end-f rthenconnection from the tethe g member 35. the tetheringcables 2 or Zaare secured to a plate "ztending upw r ly to the tail end of t e aeroplane hichmay swivel about aqbase pillar secured in .ssto. restrain its. tendency tolift. It is preferred k t 5 h ed in the ground by a, cages 0 provide a socket firmly a o in t rm into which it isbuilt. A further upwardly "BX- drome. orv ot er .rpl e and a ase pillar is fitted tending. cable 'lvextends from the base pillar in thereto. An attachment plate swive s ab ut t e so thesocket 5 andis connected to a fitting 8 secured b pillar and t tethering Cables are 0 :to a strongpartofthe fuselage frame. Ifhow- ,nectedto .theiplateand are pr V ded at t e ever the fuselage is of .monocoque construction, forward ends with readily releasable connections then the cable [may-be; connected to a sling 9 for securing to suitable parts of the aeroplane (shown in dotand 'dashrlines) which is passed such as the landing wheel axles, the undercarround the fuselage. riage legs or the wings. These cables take the for- The construction ofthe-cage 6. is ShOWll'llIl' Fig. ward; thrust when the engine is running and en- 2. This is intended primarily for anchoringthe gable thetaeroplane to face in any direction round socket 5 in ordinary open ground 'such as a field :ythe tethering member. A link extends upwardly or common or 'on desert orssandy beaches which from the base pillar, to a readily releasable conit is required to usees atemporary or emergency nector by which it is secured to the tail end of the aerodrome. The cage 6is built round a central aeroplane to control the lift thereof, and means tube lt-havingiflanges II at itstwo ends and the smayibeprovided for adjustingthe efiective length socket 5 is fitted in= theupper end of the tube l 0. -:-;:of;th'e ,1ink. The cage comprises upper and lower rectangular :f-In;:order .thatthe. inventionmay be more read-. frames 52 and-l3 formed of angle'iron and conriily; understood, examples. showing how it may be heated to the flanges II at the .two ends of the carriedg..into...efiect willcnowibeu.described.with wtubexlll. by .zthe.radiahmembersijll. The .;two

reference to the accompanying drawings, in frames l2 and I 3 are connected together by corwhich ner posts I5 and the whole structure is stifiened Fig. 1 is a perspective view of a fighter type by the diagonal stays It. The cage is of a suflicient size so that when a suitable hole is dug in the ground and the cage is placed in position in it and the material removed in digging the hole is again filled into it and firmly rammed, then the cage will be so firmly secured that it will withstand the maximum thrust or lift which could possibly be exerted on it by any aircraft intended to be tethered thereto.

An alternative form of anchorage for the socket 5 is shown in Fig. 3. This arrangement is intended mainly for use in permanent aerodromes, runways or testing sheds and comprises a strong tube of any suitable length which is set vertically in concrete 2! and has any suitable number of transverse rods 22 passed through the tube and projecting laterally into the concrete so as to secure a firm anchorage of the tube 23 in the concrete. The top of the socket 5 which is Welded into the tube 29 is preferably located in a shallow recess in the ground so that the base pillar 23 when fitted in the socket 5 does not project much above normal ground level. The base pillar 23 is provided with a shank 2d the upper part of which is a close fit in the plain bore of the socket 5 whilst the lower end of the shank 24 is screw threaded and is screwed into the lower screw threaded part of the bore 25 in the socket 5. The upper part of the base pillar 23 (shown also in Fig. 6) has a hexagonal part by which it may be screwed firmly into the socket 5. On the bearing 26 is fitted the swivel plate 2'! the bore 28 of which is radiused to allow the swivel plate to align itself with the tethering cables 2. The tethering cables 2 are each fitted with a forked cable end 29 the shank 30 of which is swaged onto the end of the cable and the forked end of each is pivoted to the swivel plate 21 by a pivot bolt 3|. The swivel plate 21 is retained in position by a collar 32 clamped against a shoulder 33 by a nut 34. The length of the bearing 26 is greater than the thickness of the swivel plate 21 so as to permit the swivel plate to rock on the bearing 26 to a limited extent to line up with the direction of pull on the cables 2.

On the top of the base pillar 23 are formed the two lugs 35 bored to receive the pivot bolt 35 which passes through them and the block 31 (see Fig. 6). To this block are secured the perforated links 38 by the pivot bolt 39 which passes through the block 3'! at right angles to the pivot bolt 36. The cable end fitting 40 of the cable I is secured between the links 38 by a pivot bolt which may be engaged with any pair of holes 42 in these two links 38 there-by providing a means of adjusting the effective length of the cable 1. The upper end of the cable I is provided with a forked end fitting 43 which may be secured to the eyebolt 8 which is fitted to a strong part of the fuselage frame of the aeroplane, or to the end of the sling 9 if the fuselage is of monocoque construction. This connection is made by the transverse pin 44 having a cranked handle 45 to facilitate its insertion and removal. Fig. 7 illustrates an alternative form of adjustment for the length of the cable 1 in which a double ended nut 46 engages with right and left hand screw threaded parts 41 and 48 secured to the cable 1 and the cable end fitting 40. Rotation of the double ended nut 46 will increase or decrease the effective length of the cable '7 according to the direction of rotation in the well known manner.

The forward ends of the cables 2 are fitted with Iii forked end fittings 50 which may be connected to anchorage plates 5| pivoted on the ends of the axles 52 of the undercarriage wheels 3 and secured by the nut 53 as shown in Figs. 4 and 5. The forked end fitting 50 may :be secured to the anchorage plate by a nut and bolt or preferably by a quickly releasable pin 54 having a cranked handle 55 similar to the pin 44 shown in Fig. 6 for securing the upper end of the cable I.

In use the aeroplane is wheeled to a position over the tethering device and is turned into wind. The swivel plate 21 is turned round the base pillar 23 and the cable ends of the cables 2 are secured to the anchoring plates provided on the aeroplane by means of the connecting pins 54. The forked fitting 43 at the upper end of the cable I is secured to the eyebolt 8 or the sling 9 by means of the pin 44. The engine of the aeroplane may then be started up and then run until suitably warmed after which any of the usual tests may be carried out. When completed the engine is throttled down and the securing pins 44 and 54 may be removed and the aeroplane is ready to take off.

I claim:

1. A device for anchoring an aeroplane comprising a single tethering member adapted to be anchored to an aeroplane landing or storage surface, said means comprising a socket, a pin mounted in said socket, a cable having one end secured to said pin and the other end adapted to be secured to a forward part of an aeroplane to take the forward thrust, a second cable having one end secured to said pin and the other end adapted to be secured adjacent the tail end of the aeroplane, said tail anchoring cable being shorter than said other cable whereby the socket is necessarily positioned adjacent the tail end of the aeroplane, thereby preventing the tail from rising.

2. An anchoring device as recited in claim 1 in which the socket is disposed vertically in the center of an open work cage, and means to secure said cage to said fixed landing or storage surface.

3. An anchoring device as recited in claim 1 in which said socket is provided with a multiplicity of transverse projecting rods enabling it to be embedded in said landing or storage surface.

4. An anchoring device as recited in claim 1 in which said forward extending cable is fixed to a collar surrounding said rotatable pin.

5. An anchoring device as recited in claim 1 in which the free ends of said cables are provided with means for rotatably coupling them to parts of said aeroplane,

- JAMES MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS N umber Name Date 1,309,036 Knight July 8, 1919 2,333,559 Grady Nov. 2, 1943 2,383,950 Baliman Sept. 4, 1945 FOREIGN PATENTS Number Country Date 51,561 Germany Jan. 10, 1912 183,469 Great Britain Oct. 11, 1923 334,509 Germany Mar. 14, 1921 418,479 France Dec. 10, 1910 711,338 France June 23, 1931

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