US3273663A

US3273663A - Vehicles for travelling over land and/or water

Info

Publication number: US3273663A
Authority: US
Publication date: 1966-09-20
Anticipated expiration: 1983-09-20

Description

p 20, 1966 c. s. COCKERELL 3,273,663

VEHICLES FOR TRAVELLING OVER LAND AND/OR WATER Filed May 6 1965 56 C. 5. CO k EELL 7 9 ATTORNEYS United States Patent 3,273,663 VEHICLES FOR TRAVELLING OVER LAND AND/0R WATER Christopher Sydney Cockerell, Bassett, Southampton, England, assignor to Hovercraft Development Limited, a company of Great Britain and Northern Ireland Filed May 6, 1965, Ser. No. 453,655 Claims priority, application Great Britain, Sept. 1, 1958, 27,978/58 Claims. (Cl. 180-7) This is a continuation-impart of applications Serial Nos. 837,502, filed September 1, 1959, and 329,562, filed December 10, 1963, now Patents Nos. 3,182,739 and 3,- 182,470, respectively.

This invention relates to vehicles for travelling over a surface and which, in operation, are supported above that surface by one or more cushions of pressurised gas formed and contained beneath the vehicle body.

In particular this invention is concerned with such gas cushion supported vehicles in which at least part of the peripheral boundary of a gas-cushion is formed by flexible means extending below the body of the vehicle as described and claimed in said patents Nos. 3,182,739 and 3,182,740.

In order to minimise the escape of gas from the pressurised gas cushion it is, of course, preferable that the flexible structures surrounding the cushion space conform as closely as possible to the contours of the surface over which the vehicle is travelling. On the other hand if contact is to take place at all between the structures mounted on the vehicle and surface irregularities or obstructions, the flexible structure should be susceptible of deflection by this contact with the least possible transmission of shock to the main vehicle structure. These two requirements are in some circumstances incompatible since surface irregularities can be of small size and random occurrence such as floating debris, or larger and systematic such as wave formations. In order to deal with small random obstructions a simple and light flexible structure is all that is necessary whereas to deal with larger irregularities a more complicated structure is likely to be required, providing for larger movements towards and away from the surface, although the speed of response required in this structure is likely to be less than that required for dealing with small obstructions. Again, if the large obstructions are systematic as in the case of waves, the structure for dealing with them may include the sophistication of' automatic operation by power means driven from a power source included on the vehicle under the control of sensing means associated with the surface of the water.

According to this invention, therefore, a vehicle of the type adapted to travel or hover over a surface and to be supported above said surface at least in part by a cushion of pressurised gas contained beneath the vehicle in a cushion space located between the underside of the vehicle and the surface over which it is travelling, comprises a main body structure, a wall structure mounted so as to extend below the main body structure and adapted to flex to accommodate major variations and irregularities in the clearance between said main body structure and the surface, said wall structure constituting a part of the peripheral boundary of said cushion space, and a further flexible structure carried by said wall structure and extending below it, said further flexible structure constituting a further part of the peripheral boundary of said cushion space and being of flexible material so as to yield to and pass over minor obstructions in its path.

The flexible structures contemplated by this invention may comprise more than two stages to provide for more than two kinds of irregularity or obstruction but in genice eral two stages will suffice, the lower stage being of quick response, light and flexible, the upper stage being more substantial, slower in response and capable of larger movements than those of which the lower stage is capable.

In order that the invention may be more clearly understood some embodiments thereof will now be described with reference to the accompanying drawings in which:

'FIGURE 1 is a diagrammatic representation of one form of vehicle according to the invention,

FIGURE 2 is an under-plan view of the vehicle shown in FIGURE 1,

FIGURE 3 is an enlarged cross-section of a peripheral portion of the vehicle of FIGURE 1,

FIGURE 4 is a front elevation of an alternative form of vehicle according to the invention,

FIGURE 5 is a cross-sectional detail of one form of structure to be used in the vehicle of FIGURE 4, and

FIGURE 6 is a cross-sectional view of an alternative construction to that of FIGURE 5.

Referring first to FIGURES 1, 2 and 3, these show a vehicle having a main body 20 which carries hydraulic rams 21 mounted in pairs around the periphery of the body, being pivoted at their upper ends to the body 20 and at their lower ends to an annular duct 22. The rams act as supporting members for the duct 22 and may perform a control function on the duct as will be referred to hereinafter. The duct forms a flexible rim and the centre of the annulus formed by the duct is closed by a flexible membrane 23. Since the duct 22 is flexible and since the rams 21, which are mounted at various points around the periphery of the body 20, are pivotally connected to both the body and the duct, it will be apparent that each portion of the duct to which a ram is connected is locally movable relative to the other portions. Air is supplied from a fan 36 driven by a motor 34 through ducts 24 in the body of the vehicle to the duct 22 by way of the flexible supply pipes 25. In this example, as shown in the cross section in FIGURE 1, the duct 22 is provided with a series of nozzles or

ports

26, 27, 28, 29 and 30 by means of'which a multiple system of air curtains is created. Air expelled from nozzle 26 is deflected and is collected by port 27. The air collected into port 27 may recirculate back into the air expelled from nozzle 26 or may be partly or wholly included in the air being expelled from nozzle 28 or even nozzle 60. A similar recirculation of the air expelled from port 28 is also obtained by collecting the deflected air flow in port29. This form of curtain fluid recovery and recirculation is more fully described in copending application Serial No. 326,497, filed November 27, 1963. Transverse ports 31, shown in FIGURE 2, are also provided so as to produce transverse curtains which divide the main curtain system into air cells each bounded by its own system of fluid curtains. These air cells enhance the stability of the vehicle.

Thus, the space beneath the membrane 23 and bounded by the flexible duct 22 contains a cushion of pressurised air which supports the vehicle clear of the surface. The multiple air curtain system which has been described serves to retain this pressurised air cushion for a part of the vertical height of the periphery of the cushion. Above this height the peripheral boundary of the cushion is formed by the

flexible nozzles

26, 27, 28, 29 and 30, projecting below the duct 22. Because of their flexible nature the nozzles can suffer contact with the surface over which the vehicle travels without sustaining damage but in the arrangement shown such contact is largely prevented or reduced by the formation of the air cells above referred to. Each such cell will experience an increase in pressure of the air within it if the clearance from the surface of the duct 22 tends to decrease at that point due, for example, to the vehicle tilting. This increase of pressure, acting upwardly on the duct system 22 will do two things. Firstly it will operate to deflect the duct upwardly so as to keep it out of contact with the surface and secondly it will exert, through the duct 22, a lifting force on the vehicle, tending to right it. The rams 21 provide a restoring force tending to maintain the duct 22 in a predetermined position relative to the main body of the vehicle. Alternatively. they may be connected to a control system which includes sensing devices such as pressure transducers which sense changes in the pressure below the duct 22 and control the supply of pressure fluid to the rams on one side or the other of their pistons so as to raise or lower the duct appropriately.

The control signals provided by the sensing devices may be derived from positions forward of the rams which they control so that the contours of the surface can be anticipated and the duct moved so as to maintain its clearance from the surface constant. Moreover, by differentially operating the rams of each pair, for example so that the outer edge of the duct 22 is raised more than the inner portion, the ducting may be tilted so as to be presented in parallel aspect to the surface if the surface slopes upwardly away from the vehicle at that point. Obviously a tilt in the reverse sense will be applied if required to match the contours of the surface.

Such an arrangement is shown in the drawings.

Pressure sensing heads

60, 61 communicate with the regions between

ports

27 and 28 and between

ports

29 and 30 respectively, in which pressures are set up related to the clearance between the vehicle structure and the surface at that point. These pressure sensing heads communicate through lines 62, 63 with a control box 64 (FIGURE 1) which controls the supply of pressure fluid to and from the rams 21, by way of pressure lines 65a, 65b, and 65c, 65d. As will be seen, the lines 65a and 65b are connected to the outer ram in reverse sense to that in which the lines 650 and 65d are connected to the inner ram. Accordingly a difference in pressure detected by the

pressure heads

60 and 61 will operate the rams diflerentially to tilt the duct structure to accommodate it to the slope of the surface. Changes in pressure affecting both heads in the same sense, however, are made to operate the rams in the same sense to raise or lower the duct structure without tilting it.

In this embodiment the cushion of air supporting the vehicle is contained below the membrane 23 at the level of the duct system from which the curtain air issues. In such an arrangement the membrane would have to withstand the full pressure of the cushion, and the stresses could be very large and may necessitate a heavy form of construction. To avoid this the space between the membrane and the body of the vehicle is enclosed by a flexible member as shown at 32 and the enclosed space filled with air at a pressure which may be approximately equal to the normal cushion pressure so that the loads on the membrane are transmitted to the bottom of the vehicle body. The membrane 23 can thus be of light construction.

In the vehicle shown in FIGURE 4 the main body 1 is surmounted by engines and 11 which drive air screws 12 and 13 for the propulsion of the craft. Directional stability of the craft is achieved by a tail fin 14 which may carry a rudder (not shown) for steering the vehicle. The lower part of the vehicle carries flexible walls 15 which enclose the air cushion and have a frusto-conical form. The sloping sides of this structure are pivotally mounted on the main body so that the lower edge of the structure can rise and fall to accommodate major irregularities in the surface while the lower edge of the structure is made light and flexible to accommodate minor i-rregu larities or obstructions.

The structure in one detailed form is shown in FIGURE 5. It consists of a series of arms 40, only one of which is shown in the drawing, pivotally attached to the body of the vehicle at 41. The arms 40 carry an impervious skin 42 which serves to contain the gas cushion and this may be of pleated form so as to increase its flexibility. This structure constitutes the first or uppermost stage of the flexible system. Depending from the outer edge of the

structure

40, 42 is a flexible skirt 43 shown concave in form. This forms the second or intermediate stage of the system. Pressurised air is delivered down a flexible pipe 44 attached to the arm 40 and discharged into the concavity on the inside of the member 43 where it is de flected inwardly to flow towards the surface in the form of a fluid curtain which assists in retaining the pressurised air cushion and forms the lowermost or third stage of the system. It will be understood that the flexible skirt 43 can ride lightly over any small obstructions which the vehicle may meet while the arms 40 permit a greater degree of movement to enable the vehicle to pass over larger obstructions.

FIGURE 6 shows an arrangement similar to that of FIGURE 5 and applicable to a vehicle of the kind shown in FIGURE 4. In this arrangement the arm 40 is replaced by a pivoted

parallelogram structure

50a, 50b, 50c, 50d, on the outside of which a flexible skin or membrane 51 is supported. Attached to the bottom of the parallelogram structure is an inflated flexible structure 52, in the bottom wall of which are

ports

53 and 54 from which air delivered to the interior of the structure 52 escapes in the form of

curtains

55 and 56. Perssurised air is delivered to the interior of the structure 52 through a flexible pipe 57. The operation of this arrangement is similar to that of the arrangement shown in FIGURE 5 except that by virtue of the parallelogram linkage the flexible structure 52 is maintained in the attitude shown throughout the rise and fall of the parallelogram arms so that the bottom part of the structure 52 is at all times presented in a substantially horizontal attitude towards the surface over which the vehicle is travelling. In this embodiment the

curtains

55 and 56 cause the formation of a subsidiary cushion 58 of pressurised fluid beneath the structure 52 which assists in maintaining the structure clear of the surface -over which it is passing. Thus if the clearance tends to decrease the pressure in the subsidiary cushion will go up and this will tend to compress the structure 52 and at the same time tend to lift the whole of the structure on its parallelogram linkage. For minor irregularities compression of the structure 52 will suffice to maintain clearance from the surface whereas larger irregularities or obstructions tend 'to swing the whole structure upwardly to maintain it out of contact with the surface.

Instead of or in addition to the control of this flexible structure in the manner just described it may be controlled by power means operating through a hydraulic ram 58 which operates across a diagonal of the parallelogram linkage. This ram may either be used simply to provide suitable damping of the system or may be operated by pressure fluid to produce positive actuation of the system in response to control signals picked up by sensing devices which detect variations in the clearance between the vehicle structure and the surface over which it is travelling and apply these signals to control the hydraulic ram so as to maintain or tend to maintain a constant clearance.

In these drawings a pressure sensing head 70 is connected through a line 71 to a control box 72 which controls the supply of pressure fluid from a supply line 73 to the lines 74 and 75 which supply opposite ends of the ram 58. The ram 58 can thus be expanded or contracted in accordance with the pressure detected beneath the flexible structure 52 to lower it or raise it accordingly.

I claim:

1. A vehicle of the type adapted to travel or hover over a surface and to be supported above said surface at least in part by a cushion of pressurised gas contained beneath the vehicle in a cushion space located between the underside of the vehicle and the surface over which it is travelling, comprising a main body structure, a wall structure mounted so as to extend below the main body structure and adapted to flex to accommodate major variations and irregularities in the clearance between said main body structure and the surface, said wall structure consituting a part of the peripheral boundary of said cushion space, and a further flexible structure carried by said wall struc ture and extending below the latter, said flexible structure constituting a further part of the peripheral boundary of said cushion space and being of flexible material so as to yield to and pass over minor obstructions in its path, said flexible structure being lighter and capable of quicker response to variations and irregularities in the surface over which the vehicle is travelling than said wall structure.

2. A vehicle as claimed in claim 1 in which said flexible structure is hingedly mounted on said wall structure and is movable relative thereto so as to present a preferred aspect towards the surface as irregularities in the shape of the surface are encountered.

3. A vehicle of the type adapted to travel or hover over a surface and to be supported above said surface at least in part by a cushion of pressurised gas contained beneath the vehicle in a cushion space located between the underside of the vehicle and the surface over which it is travelling, comprising a main body structure, a wall structure mounted so as to extend below the main body structure and adapted to flex to accommodate major variations and irregularities in the clearance between said main body structure and the surface, said wall structure constituting a part of the peripheral boundary of said cushion space, a further flexible structure carried by said wall structure and extending below the latter, said flexible structure constituting a further part of the peripheral boundary of said cushion space and being of flexible material so as to yield to and pass over minor obstructions in its path, and power means for flexing said wall structure in response to detected variations in the clearance between the main body structure and the surface.

4. A vehicle of the type adapted to travel or hover over a surface and to be supported above said surface at least in part by a cushion of pressurised gas contained beneath the vehicle in a cushion space located between the underside of the vehicle and the surface over which it is travelling, comprising a main body structure, a wall structure mounted so as to extend below the main body struc ture and adapted to flex to accommodate major variations and irregularities in the clearance between said main body structure and the surface, said wall structure constituting a part of the peripheral boundary of said cushion space, a further flexible structure carried by said wall structure and extending below the latter, said flexible structure constituting a further part of the peripheral boundary of said cushion space and being of flexible material so as to yield to and pass over minor obstructions in its path, said wall structure being flexible in planes extending radially of said main body structure, and power means for flexing said Wall structure in said planes so as to vary the aspect presented by said flexible structure towards said surface.

5. A vehicle of the type adapted to travel or hover over a surface and to be supported above said surface at least in part by a cushion of pressurised gas contained beneath the vehicle in a cushion space located between the underside of the vehicle and the surface over which it is travelling, comprising a main body structure, a wall structure mounted so as to extend below the main body structure and adapted to flex to accommodate major variations and irregularities in the clearance between said main body structure and the surface, said wall structure constituting a part of the peripheral boundary of said cushion space, and a further flexible structure carried by said wall structure and extending below the latter, said flexible structure constituting a further part of the peripheral boundary of said cushion space and being of flexible material so as to yield to and pass over minor obstructions in its path, said wall structure including hinged arms swingable in planes extending radially outwardly from said main body structure and parallelogram linkages attached to said hinged arms, and said flexible structure being attached to said arms and to said linkages whereby the aspect of said flexible structure towards the horizontal is maintained substantially constant throughout the swinging movements of said arms.

References Cited by the Examiner UNITED STATES PATENTS 3,182,739 5/1965 Cockerell -7 3,182,740 5/1965 Cockerell 180-7 3,191,705 6/1965 Jones et a1. 1807 3,211,246 10/1965 Lews 180-7 A. HARRY LEVY, Primary Examiner.

Claims

1. A VEHICLE OF THE TYPE ADAPTED TO TRAVEL OR HOVER OVER A SURFACE AND TO BE SUPPORTED ABOVE SAID SURFACE AT LEAST IN PART BY A CUSHION OF PRESSURISED GAS CONTAINED BENEATH THE VEHICLE IN A GUSHION SPACE LOCATED BETWEEN THE UNDERSIDE OF THE VEHICLE AND THE SURFACE OVER WHICH IT IS TRAVELLING, COMPRISING A MAIN BODY STRUCTURE, A WALL STRUCTURE MOUNTED SO AS TO EXTEND BELOW THE MAIN BODY STRUCTURE AND ADAPTED TO FLEX TO ACCOMMODATE MAJOR VARIATIONS AND IRREGULARITIES IN THE CLEARANCE BETWEEN SAID MAIN BODY STRUCTURE AND THE SURFACE, SAID WALL STRUCTURE CONSITUTING A PART OF THE PERIPHERAL BOUNDARY OF SAID CUSHION SPACE, AND A FURTHER FLEXIBLE STRUCTURE CARRIED BY SAID WALL STRUCTURE AND EXTENDING BELOW THE LATTER, SAID FLEXIBLE STRUCTURE CONSTITUTING A FURTHER PART OF THE PERIPHERAL BOUNDERY OF SAID CUSHION SPACE AND BEING OF FLEXIBLE MATERIAL SO AS TO YIELD TO AND PASS OVER MINOR OBSTRUCTIONS IN ITS PATH, SAID FLEXIBLE STRUCTURE BEING LIGHTER AND CAPABLE OF QUICKER RESPONSE TO VARIATIONS AND IRREGULARITIES IN THE SURFACE OVER WHICH THE VEHICLE IS TRAVELLING THAN SAID WALL STRUCTURE