US3559758A - Fluid cushion confining device - Google Patents

Fluid cushion confining device Download PDF

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Publication number
US3559758A
US3559758A US740653A US3559758DA US3559758A US 3559758 A US3559758 A US 3559758A US 740653 A US740653 A US 740653A US 3559758D A US3559758D A US 3559758DA US 3559758 A US3559758 A US 3559758A
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US
United States
Prior art keywords
frame
cushion
bearing surface
fluid
edge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US740653A
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English (en)
Inventor
Jean Henri Bertin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bertin Technologies SAS
Original Assignee
Bertin et Cie SA
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Filing date
Publication date
Application filed by Bertin et Cie SA filed Critical Bertin et Cie SA
Application granted granted Critical
Publication of US3559758A publication Critical patent/US3559758A/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60V—AIR-CUSHION VEHICLES
    • B60V3/00—Land vehicles, waterborne vessels, or aircraft, adapted or modified to travel on air cushions
    • B60V3/02—Land vehicles, e.g. road vehicles
    • B60V3/04—Land vehicles, e.g. road vehicles co-operating with rails or other guiding means, e.g. with air cushion between rail and vehicle

Definitions

  • the invention relates to plenum chamber means for confining at least one fluid cushion for ground effect machines.
  • the devices which confine the fluid between a frame integral with the machine and an opposite bearing surface such as the ground, comprise a wall. generally movable with respect to the frame, which bounds the cushion along at least part of its periphery, the wall having a free end in the direction of the bearing surface.
  • the invention applies both to freely moving and to guided vehicles; in the latter case it applies both to the lifting and the guiding cushions.
  • the sidewalls of the plenum chamber cooperate with the end of the chamber and the surface of the ground to from a space in which there is an excess pressure p with respect to the outside of the cushion (see FIG. 12).
  • the bottom of the plenum chamber is separated from ground level by a height h called the flight or outlet height, the size of which depends on a compromise chosen between at least two requirements.
  • the height of flight cannot be too low, since this affects the capacity of the vehicle for overcoming obstacles on its path.
  • the height must not be too great, since the resulting escape rate Q would be very high and would require a prohibitively large source or sources of energy to supply the lift. It can easily be shown that the lifting power is proportional to the ratio Lh/S, which reduces to h/D for plenum chambers having a circular periphery.
  • L is the perimeter of the free edge of the plenum chamber
  • S is the support area bounded by the perimeter
  • h is the space between the free edge and the bearing surface
  • D is the diameter of a circular free edge (see FIGS. 12 to 14).
  • the cushion can be fed more economically in proportion as these ratios are smaller.
  • the rigidity of the system can be defined as the ratio of the variation in the force bearing the cushion to the variation in the height of flight associated with it. If p is the maximum excess pressure in the cushion when the escape rate is zero (h tends towards zero), the expression for the rigidity R is:
  • this rigidity approaches infinity when h/S, (h/D for plenum chambers with a free circular edge) approaches zero, unless (p p) simultaneously approaches zero owing e.g. to the shape of the characteristic curve of the source of compressed fluid.
  • economic operation appears to exclude operation at low rigidity or great elasticity, which means that the system cannot be comfortable.
  • the aim of the invention is to reconcile these two requirements by disassociating the effect of the outlet cross section from the effect of the lift area.
  • the fluid does not escape around the perimeter L of the cushion, but at fixed points through outlet means cross section but having a shape such that the variation in ratio h/S or h/D is much more favorable to the flexibility of the system without increasing the expense.
  • a confining means is characterized by a combination of means for keeping the free end of the peripheral confining wall in substantially leak-obstructing contact engagement with the bearing surface, and by at least one outlet means of variable and controllable cross section.
  • the walls can move with respect to the vehicle frame and can thus climb obstacles and/or follow the shape of the bearing surface while remaining in substantially sealingtight contact with it.
  • the outlet means of controllable cross section comprises an unwalled part of the cushion periphery.
  • the maximum cross section is advantageously adjusted by a closure member of adjustable position, e.g. by a sliding closure member which can be adjusted in dependence on the internal pressure in the fluid cushion and/or by the pilot of the vehicle.
  • the fluid escaping from the cushion is controlled by ducts in the plates or the like.
  • the flow can advantageously be controlled by the ducts in cooperation with closure plates which are stationary with respect to the vehicle.
  • At least one of the controlled outlet means is disposed at the rear of the machine, so that at least part of the flow escaping from the cushion can be used to drive the vehicle.
  • FIG. I is a vertical section of a means for confining a fluid cushion, comprising an adjustable outlet means according to a first embodiment of the invention
  • FIG. 2 is a cross section along Il-II in FIG. 1;
  • FIG. 3 is a larger-scale view of part of FIG. 1;
  • FIG. 4 is a view along IV-IV in FIG. 3;
  • FIG. 5 is a view of part of FIG. 1, showing an elevation of a means for closing the adjustable outlet means;
  • FIGS. 6 and 7 are sections respectively along VI-VI and VII-VII of the closure system shown in FIG. 5;
  • FIG. 8 is a cross section similar to FIG. 3, showing an arrangement of the outlet means in a second embodiment of the invention.
  • FIG. 9 is a cross section along IX-IX of FIG. 8.
  • FIG. 10 shows an elevation of a ground effect vehicle to which the invention can apply.
  • the right part of the FIG. shows an advantageous arrangement of the outlet means
  • FIG. 11 is a section along XI-Xl of FIG. 10.
  • FIGS. 12 to 14 are diagrams of the different physical or geometrical quantities mentioned at the beginning of the description.
  • FIG. 12 is a side view of a confining plenum chamber" means and FIGS. 13 and 14 show two views from beneath of the device shown in FIG. 12, corresponding to two different forms of the device.
  • FIGS. 1 to 7 show a device for laterally bounding a fluid cushion supplied through orifices 23 and used for lifting a ground efi'ect machine whose frame is denoted by reference 2.
  • Angle members 3 rigidly attach the frame to a peripheral plate 1. These components are shown more clearly in FIGS. 3 and 4.
  • Plates 4 disposed parallel to peripheral plate 1 are kept at a fixed distance from plate 1 towards the inside of the cushion, by means of bolts 5 having a shoulder 6 for the purpose.
  • Rigid or semirigid plates or the like 7 formed with oblong apertures 16 round bolts 5 can slide vertically between plates 1 and 4.
  • the plates at their free end E are in contact with a bearing surface.
  • the surface used as an example in the drawings is a prepared track 8.
  • the sliding plates 7 are kept with their free ends E in constant contact with the bearing surface, due to the action of leaf springs 9 or any equivalent resilient device.

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  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Mattresses And Other Support Structures For Chairs And Beds (AREA)
  • Combined Devices Of Dampers And Springs (AREA)
US740653A 1967-08-22 1968-06-27 Fluid cushion confining device Expired - Lifetime US3559758A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR118640A FR1541795A (fr) 1967-08-22 1967-08-22 Perfectionnements aux dispositifs de confinement de coussins de fluide sous pression

Publications (1)

Publication Number Publication Date
US3559758A true US3559758A (en) 1971-02-02

Family

ID=8637200

Family Applications (1)

Application Number Title Priority Date Filing Date
US740653A Expired - Lifetime US3559758A (en) 1967-08-22 1968-06-27 Fluid cushion confining device

Country Status (4)

Country Link
US (1) US3559758A (enExample)
BE (1) BE718874A (enExample)
DE (1) DE1780213A1 (enExample)
FR (1) FR1541795A (enExample)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3695382A (en) * 1969-09-26 1972-10-03 Aerotrain Devices for supplying the pressurized fluid cushions of a ground-effect vehicle

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3695382A (en) * 1969-09-26 1972-10-03 Aerotrain Devices for supplying the pressurized fluid cushions of a ground-effect vehicle

Also Published As

Publication number Publication date
DE1780213A1 (de) 1971-01-21
BE718874A (enExample) 1969-01-31
FR1541795A (fr) 1968-10-11

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