US1699672A - Alighting means for lighter-than-air ships - Google Patents

Description

Jan. 22, 1929.

W. V. N. POWELSON ET AL ALIGHTING MEANS FOR LIGHTER-THAN-AIR SHIPS Filed Sept. 6, 1921 BY. 7% M Patented Jan. 22,1929.

ATENT or FICE.

WILFRID V. N. EOW'ELSON AND VIAEEEN TRAVELL, OF NEW YORK, N. Y.

ALIGHTING Means res menses-marinara SHIPS. 1

Application filed September 6, 1921. Serial no. 498,607.

This invention relates to improvements in alighting means for lighter-than-air ships. Up to the present time, airships of large size have never been brought safely to rest on land or ater without the assistance of a large number of attendants. It is an object of this invention to provide means whereby an. airship may safely alight on either land or water and without the assistance of any attendant wl'iatever. l

Airplanes have been commonly equipped with wheels for running on the ground but if an airship were equipped with the same type of wheels and wheel attachments as those used on airplanes, there would result, on landing, stresses which would distort or destroy the structure of the airship. lVe have invented ameans in connection with the use of landing wheels whereby the weight of the airship is distributed among several wheels, regardless of unevenesses of the surface of the ground and whereby the stresses produced inth'e structure of the airship, due to its weight being supported by these wheels, are kept within predetermined limits.

We also apply the same means or a modification thereof to permit the safe alighting of an airship on the surface of a body of water and for the prevention of the destruction of the airship due to wave action while the airship is floating on water.

Also, our invention provides improved means for withdrawing the alighting wheels within the envelope of the airship during flight. i These several objects are attained in our improvement by attaching wheels to an airship along the lower part thereof, by means of arms which are pivotally connected to the airship. Pockets are provided in the exterior envelope, into which these wheels with their supporting arms may be withdrawn during flight Previous to alighting, the wheels are let down, the arms being provided with limit stops which prevent the wheels from being lowered too far. The wheels are held in this lowered position by means of a spring, or other device, exerting an approximately constant force, predetermined in amount. The structure of the airship may be designed to transmit different loads to different wheels when resting or running on ground or water. Assuming that the design such that the wheels are to take approxibately equal loads, when the airship alights on an uneven surface of ground, the wheels vwill be raised to different elevations by the unevenness of the ground, but each wheel will carry no more than its own proportion of the weight of the airship, producing in the airship structure no more than the predetermined stresses. lt should be noted that even a large airship on alighting may have a weight only slightly in excess of the Weight of the air displaced thereby and that the actual load to be carried by each wheel may be no greater than the load which is carried by a landing wheel of a much smaller airplane receiving no support from lighterthan-air gas.

Such wheels may be used on an airship not only for alighting, but may be used in con nection with airships, heavier-tl1an-air and equipped with lifting planes, to run along the ground and thus obtain proper speed, so that the lifting planes at such speed may raise the airship from the ground. This method of launching an airship permits the loading of the airship beyond the lifting power of its gas and enables an airship of a given size to carry a much greater load either of fuel or cargo than it could otherwise carry. Such an advantage alone is of prime importance in the successful financial operation of a commercial line ofairships.

For alighting on water and supporting the unbalanced weight of an airship thereon, the

wheels may be of larger size and fitted with water-tight air chambers, thereby providing a buoyancy for each wheel equal to or 1n excess of the load which it is designed tocarry.

These wheels may have their outside rims adapted for running on the ground, so that, when thus equipped, an airship may alighteither on land or water. When an airship is floating on water, supported by such wheels, the effect of waves will be to cause the various wheels to rise and fall with the/wave motion, but each wheel can transmit to the structure of the airship nogreater stress than is de termined by the force of the spring or other device which holds it downward. At the same time, the airship is supported at such elevation above the water surface that the fragile envelope of the airship escapes the destructive force of the waves. Without such a resilient means of support, even small waves would produce in the structure of an airship stresses far greater than airships can withstand as at present designed or, if designed ture would probably have to be so increased the patent shall cover spring 9 as to be prohibitive.

With airships thus provided with alighting wheels, the cost and difficulty of obtaining suitable mooring stations will be greatly reduced. Bays, rivers and lakes having suitable area and protection from the wind may be used as intermediate and terminal stations, or if there exists no such body of water in a locality where a station is desired, a dike canbe built around a swamp or low lying piece of ground and an artificial pond created at much less cost than would be en- .5 countered in the purchase and leveling of an equal area of ground, free from water, as would be required for the manipulation of airships according to present methods of operation. 0

In the practical application of the invention thus set forth, various devices may be employed in substitution for those which are herein shown as illustrating the principles involved; and variations may be made in many respects without departing from the scope of the invention. 7 It is intended that by suitable expression in the appended claims whatever features of patentable novelty exist in the invention disclosed.

In the accompanying drawings, which are somewhat diagrammatic:

Fig. 1 is a side elevation of an airship equippedwith alighting wheels;

Fig. 2 is a side elevation of a portion of same to a larger scale and shows an alight ing wheel in its lowered and raised positions;

. Fig. 3 is a cross sectional view on line 3-3 of Figs. 1 and 2;

Fig. t shows the alighting wheel on a still larger scale with means for providing resiliency, being a longitudinal section through one of the pockets;

r Fig. 5 is an end elevation of the same; and

Fig. 6 is a sectional View of a wheel adapted for alighting on both land and water.

In Fig. 1, the airship 1, with its power car 2 is shown supported by wheels 3 on a ground surface. These wheels are distributed along the length of the ship, and are in rows, one at each side, as seen in Fig. 3.

In Fig. 2 a wheel is shownin its lowered position, when the ship is supported by arms 4, and in raised position at 8, when the wheel is retracted within pocket 5, within the envelope 6 of the airship, as when in flight.

Figs. 4 and 5 on a larger scale show the which holds the wheel with approxconstant force. in a downward position, the stop 7 preventing it being pulled downward further than is desirable. The spring and stop cooperate to set the arm 4 in an obliquely, trailing position so that it can both transmit weight to the ground, and yield to the rear and upward on encounterimately V rope 10 passing ing an obstacle when running forward. The spring is shown attached to the arm 4 by a around a sheave 11 supported by a bracket 18 attached to a cross beam 15 forming part of theframework. The latter, as illustrated, is so positioned with respect to both the axle 8 and the short arm of arm or lever 4, that the perpendicular distance from the axle or fulcrum 8 to the line of the rope 10 is substantially the same at both of the illustrated limits of movement. This makes it possible, with a suitably chosen spring 9, to maintain a constant limit for the supporting effect of the wheel on the airship no matter whether the wheel is in its lowest position, as shown in full lines, or in its high dotted position; and this is also approximately true of any intermediate position. This is obvious mathematically upon computing a moment equation about the axle 8, and noting that the moment arm from axle 8 to the line of the vertical thrust or supporting force acting vertically through the wheel varies in proportion to the change in the spring strength as the latter is elongated or shortened by the swing of the lever or arm 4.

Since these elements vary proportionally,

and the moment arm from axle 8 to the force acting along the rope 10 remains ap roximately constant, it must follow that the remaining element of the moment equation, namely, the supporting force or vertical thrust at the wheel, must also be constant. Accordingly the invention enables the limit of supporting effect of each wheel to be predetermined and to be maintained constant. Until this limit is reached the wheel occupies the full line position illustrated; and the total pull of the spring is resisted either at the stop 7 or at the ground, or in part at each, as the case may be; but when this limit is reached the wheel is swung upward about the axle 8; That is, when the weight of the ship rests on the wheel too heavily the sprin yields; the other wheels take u the loac, the ship first settling lower if tiey are not already touching ground; and the load is thus distributed among them all. The springs keep each single wheel 3 extended so as to carry its full part of the load, and to prevent it from transmitting undue stress to its part of the frame. Various other means may be employed for accomplishing the same result. The axle 8 about which arm 4 rotates to position 4 is supported by a bracket 19 attached to a beam 14 which is part of the structure of the airship. There is shown a hook 12, attached by rope 13 to the structure, for holding the wheel in its retracted position 3. For withdrawing the wheel into the envelope a rope 13 maybe provided as a continuation of rope 13, around a sheave 12, which may be operated from any convenient place above in the body of the ship.

In Fig. 6, the wheel?) is shown with a tread 16 adapted for running on a groundsurface,

and with a water-tight aircompartment 17 which provides buoyancy when floating on water.

vVhen the invention is applied to a lighterthan-air ship which is heavier with its load than the air it displaces, the ship may have integral air-planes to carry the excess weight in flight and these wheels will carry on land the amount by which the weight of ship on ceeds the buoyant force.

lWhat we claim is:

1. The combination, with an airship containing lighter-than-air gas, of a multiplicity of landing supports therefor distributed fore and aft along its underside; said supports each comprising a ground engaging member mounted on and extensible from the frame of the ship and adapted to yield toward it at substantially constant pressure upon contact with the ground; a stop arranged to limit the travel of said member from the frame; a spring having operating connection with said member and anchored to a rigid part of the frame in position for holding said member against said stop with a pressure suflicient tor the said member to support a limited portion of the weight of the airship without yielding; the mounting of said member and its spring being adapted for said member to yield when the ground pressure upon it on ceeds said limit.

2. In an airship containing lighter-thanair gas, and having a multiplicity of ground engaging supports distributed over and a-ttached to the lower portion of said airship, means for distributing the landing stress of the airship among the several supports comprising, as a part of each said support, a lever having a ground-engaging end, a spring, and connectionsbetween the lever, the spring and the body of the airship whereby, upon sustaining a ground pressure of predetermined amount the support yields toward the body of the ship, and the said connections are arranged to provide for said pressure to be at a certain spring position, with there after during the yielding such little increase of resistance to ground pressure as to let the ship drop until increased proportion of ground pressure results on other supports.

3. The combination, with an airship containing lighter-than'air gas, of a multiplicity of yielding supports distributed fore and aft over the underside of the ship each comprising a ground-engaging member, a spring for said member, and connections between the member, spring and the frame of the airship; each yielding support having a ship-supporting strength commensurate with the landing stresses arising from the particular portion of the ship where the particular suport is located, and each yielding support eing constructed, mounted on and connected to the ship so that for landing stresses, higher ground pressure about said whereby the spring, acting upon the ground member through said element, holds said member in repose until a predeterminable load is carried by said member and then permits said member to yield without further repose when said load is exceeded notwithstanding that the load remains substantially at said predetermined value at yielding is initiated.

5. Supporting means comprising a ground engaging member adapted to yield toward the thing supported, and means for maintaining constant the pressure of said member on the ground, during its yielding, irrespective of its degree of yield toward the thing supported, comprising a pivoted support for said member; means applying force to said member to oppose its yielding and means interposed between the last said means and the member whereby the moment of said opposing force about the pivot of the support counterbalances the moment of said pivot during the which said yielding of the member.

6. Supporting means for an airship comprising a ground engaging wheel; a lever, carrying the wheel and fulcrumed on the airship so as to permit the wheel to move toward it; and spring means secured to the airship and having connection with said lever; and means cont-rolling the application of the spring force whereby the moment of resist ance at the end of yielding is approximately the same as at its beginning.

7. Supporting means for an airship comprising a lever fulcrumed on theairship and having a yieldable connection therewith including a spring, and a wheel mounted on said lever in ground engaging position and movable therewith about the fulcrum toward the airship; and guiding means for said yieldable connection providingfor change of the spring force substantially inproportion to the change in the horizontal component of the distance between said fulcrum and the wheel.

8. Supporting means for an airship comprising a ground engaging wheel; a lever carrying said wheel and being fulcrumed to permit the Wheel to move toward the airship; a spring force, acting on said lever; and means whereby the moment arm of said spring about said fulcrum remains approximately constant during the turning of the lever; said spring force varying in proportion to the moment arm of the force transmittedby the wheel, whereby thelatter force is maintained substantially constant during movement of the wheel toward the airship.

9. Supporting means comprising a ground engaging member adapted to yield toward the thing supported; force exerting means attached to the thing supported,having connection with said member; and guiding means for said connection whereby the force exerted by the force exerting means on the member increases in proportion as the momentarm of the ground pressure on the said member increases during the yielding.

10. Supporting means comprising a ground engaging member adapted to yield toward the thing supported; a lever pivoted intermediate of its ends on the thing supported and carrying said member on one of its arms; a spring attached to the thing supported having connection with the other arm of said lever and adapted to yield at a predetermined pressure upon the member; and guiding means for said spring connection whereby as the lever swings the said predetermined pressure is maintained.

11. Supporting means comprisin a ground engaging member adapted to yie d toward the thing supported; a lever pivoted intermediate of its ends on the thing supported and carrying said member on one of its arms; a spring attached to the thing supported having connection with the other arm of said lever and adapted to yield at a predetern'iined pressure upon the member; and guiding means for said spring connection whereby as the lever swings the angle between said connection and the lever remains substantially unchanged.

Signed at New York, N. Y., this first day of July, 1921.

WILFRID V. N. POWELSON. \VARREN TRAVELL.

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