US3601062A - Ground effect machines - Google Patents
Ground effect machines Download PDFInfo
- Publication number
- US3601062A US3601062A US864685A US3601062DA US3601062A US 3601062 A US3601062 A US 3601062A US 864685 A US864685 A US 864685A US 3601062D A US3601062D A US 3601062DA US 3601062 A US3601062 A US 3601062A
- Authority
- US
- United States
- Prior art keywords
- pressure
- machine
- speed
- cushion
- gap width
- 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
Links
- 230000000694 effects Effects 0.000 title claims abstract description 13
- 239000012530 fluid Substances 0.000 claims description 36
- 238000005192 partition Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 5
- 238000007599 discharging Methods 0.000 claims description 3
- 230000003068 static effect Effects 0.000 description 3
- 244000025352 Artocarpus heterophyllus Species 0.000 description 1
- 235000008725 Artocarpus heterophyllus Nutrition 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Images
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 present invention relates to ground effect craft or machines, i.e., craft or machines whose lift and possibly guidance are at least partly performed by pressure fluid cushions.
- Cushions of the kind specified are fed with fluid at a pressure high enough for them to equilibrate the load applied to them, having regard to their dimensions. More particularly, cushions which at least provide lift for the machine equilibrate the weight thereof. However, at high speeds the dynamic forward pressure may exceed the cushion pressure required for the satisfactory operation of the machine, in which case the cushions are directly fed via the gap at the front of the machine lying between the structure thereof and/or the cushion-confining device, if any, and the surface along which the machine moves.
- the present invention relates to a control system by means of which, when machine speed increases, the daylight clearance is gap at the front surface of the machine between the structure thereof and/or the cushion-confining devices, if any, which extend downwardly from the machine, and the surfaces along which the machine is lifted and guided, is progressively reduced, so as to reduce the direct feed to the cushions by the dynamic pressure set up by the speed of the machine.
- daylight clearance is well known in the art and signifies the gap between the lowest part of an air cushion vehicle and the surface when the vehicle is supported on its cushion which acts against such surface.
- the presentinvention also relates to devices enabling the control function to be performed.
- a first embodimentof the invention to confine a cushion over at least portion of its front surface, use is made of a mobile member formed, for instance, by a transverse plate which is articulated around an axis of its plane and whosefront surface is subjected to the dynamic forward pressure. Its rear surface is subjected to the pressure of the cushion and resilient return means acting on either side of a neutral position corresponding to zero stressing.
- the mobile plate can be connected to a mechanical adjusting device, for instance, a jack.
- the mobile plate can also be subjected to the action of a force set up by a negative pressure in a chamber advantageously connected via a conduit to a zone in which the static pressure is low.
- a chamber advantageously connected via a conduit to a zone in which the static pressure is low.
- such chamber can be connected to the periphery of the outer fluid inlet conduit of the device feeding the cushions with pressurized fluid.
- the value of the static pressure can vary with the speed of the machine if, for instance, such inlet discharges towards the front of the machine.
- a nozzle directed towards the supporting surface and extending transversely and substantially over the whole cushion width, so that when the nozzle is fed with pressurized fluid it produces a curtain which reduces the flow section at the front of the cushion.
- the nozzle is directed towards the front of the machine in relation to the preferential direction of travel thereof.
- a plurality of orifices can be substituted for the nozzle, the orifices being close enough together to form a substantially continuous curtain.
- the gaseous fluid required for cushion operation is advantageously supplied via a fluid compressor driven by suitable means and interposed between an outer fluid inlet fed by the dynamic pressure and the cushions.
- cushion pressure is brought to its correct value either by the characteristics of the compressor and the feed circuit, or by any other automatic or nonautomatic means.
- the feed collectors of the cushions can have calibrated flaps allowing excess pressure fluid to escape to atmosphere.
- the machine can be so designed that as a result of its external aerodynamics a resulting force is directed towards the supporting surfaces of the machine. In this way the useful load of the machine is effectively increased when speed rises.
- the pressure in the cushions therefore also increases in relation to speed.
- FIG. 1 is a diagrammatic elevation of a ground effect machine comprising improvements according to the invention and associated with a guide track.
- FIG. 2 is an enlargement of a detail shown at 11 in FIG. 1.
- FIG. 3 is a view similar to Fig. 2, showing a second embodiment of the invention.
- FIGS. 4 and 5 are half views of a ground effect machine associated with a guide track and comprising improvements according to the invention.
- FIG. 6 is a section, taken along the line VI-Vl in Fig. 4.
- FIG. 7 is a section, taken along the line VII-VII in Fig. 5.
- Fig. 1 shows a machine 2 cooperating with a guide track I of inverted T cross section.
- the front of the machine has outer fluid pickups 3 which feed compressors 4 driven by a motor 5.
- the fluid leaving each of the compressors is directed into a duct 6 feeding, via branches 7, 8, at least one cushion bearing against the carrying portions 12 of the track 1, and at least one cushion bearing against the central extension 13 of the track 1.
- the ducts 6 At their downstream ends, the ducts 6 have flaps l0 kept closed by calibrated springs 100, the purpose of the flaps being to keep the pressure in the ducts 6 at the correct value.
- the cushions are substantially rectangular in plan and bounded at their portion adjacent the structure of the machine by a partition 14, being bounded laterally and at the rear by I enclosures to be progressively reduced when the dynamic pressure due to speed exceeds the nominal value.
- This device comprises an apron l7 articulated around a pivot 18 unitary with the partition 16 and prolonging the latter in the direction of the supporting surface; the apron 17 is subjected to the action of the forces due to the pressure of the cushion and the tension of a spring 19 on the one hand, and the action of the forces set up by the dynamic forward pressure on the other.
- a stop 21 limits the travel of the apron 17.
- a joint cover 22 advantageously provides sealing tightness in line with the articulation of the apron.
- the device operates as follows:
- the apron -17 occupies a position such as that, for instance, shown in Fig. 2. Such position is determined on the one hand by the action of the force set up by the pressure of the cushion, which acts on the whole rear surface of the apron, and on the other hand by the dynamic forward pressure and the action of the spring 19. If, for instance, the external aerodynamics of the machine are such that a resulting force is directed towards the cushion-supporting surface when machine speed increases, cushion pressure also increases with speed. The force set up by cushion pressure on the apron 17 increases so that the flow section via which the enclosure containing the fluid cushion can be fed with fluid from outside by the dynamic forward pressure is progressively reduced.
- the force set up by such pressure also increases, but remains less than the force set up by cushion pressure, since the front surface of the apron 17 is exposed to the excess pressure resulting from the speed of. movement of the machine only over a very small proportion of the apron surface, since it is masked by the partition 16.
- a mechanical device such as a jack 23, can control the apron 17, more particularly if the partition 16 is eliminated.
- the jack can .be controlled by one or more operational parameters of the machine, such as, for instance speed, cushion pressure, by means of devices not shown, or else the jack can be controlled from the machine control panel.
- the assembly made up by the apron 17 and the spring 19 can be replaced by a flexible strip which has the same displacement as the apron 17 and the same resilience as the spring 19 and is attached to the partition 16 without an articulation.
- FIG. 3 shows a variant embodiment of the invention.
- a cushion 9 situated forward of the machine in relation to a preferential direction of movement thereof, has at its front an apron articulated around a pivot 26 which is substantially parallel with the surface along which the machine moves and extends through the center of the apron.
- the apron has one end 25a having a friction joint 27 cooperating with the inside walls of a chamber 28. Stops 29, 30 limit the movements of the apron.
- a fluid pickup 31 connects the chamber 28 to the conduit 3a upstream of a compressor 4. When the machine moves, the apron is subjected to the action of the following forces:
- That half of the apron cooperating with the chamber 28 is subjected on its front surface to the action of the forces set up by a static excess pressure due to the movement and on its rear surfaceto a negative pressure in the chamber 28 maintained by the fluid pickup 31 discharging into the conduit 3a, the value of such negative pressure varying with machine speed.
- the other half of the apron 25 is subjected on its front surface to the action of the forces set up by the dynamic pressure due to the movement, and on its rear face to the pressure of the cushion 9
- a sp'ring32 possibly associated with a shock absorber, is provided to make apron movements progressive.
- the spring operates by extension and tends to retain the apron 25 against the stop 29.
- the device operates as follows:
- the plate 25 During travel, the plate 25 takes up an intermediate position between the two stops 29, 30, for instance the position shown in the drawings.
- This arrangement is substantially independent of the pressure caused by the movement, since such pressure acts on the front surface of the plate 25 on either side of the pivot 26. in proportion as machine speed increases, there is a greater increase in speed at the lower portion of the apron 25, the'result being reduced excess pressure. The resultant of the forces therefore tends to move away from the pivot 26 in the direction of the end 25a of the apron 25, and this is favorable to the operation of the apparatus.
- the pressure pickup 31 might be disposed on the sides of the vehicle or in a zone where there is normal atmospheric pressure, more particularly if cushion pressure increases in relation to machine speed, as seen with relation to Fig. 2.
- FIGS. 4-6 and 7 illustrate other devices for the performance of the method according to the invention. These Figures show the front of a ground effect machine lifted and guided by pressure fluid cushions 35, 36 supported on a track 37.
- the free end 39a of the wall 39 comprises a nozzle 41 extending over substantially the whole length of the wall.
- the nozzle 41 is adapted to deliver a flow directed towards the front of the machine in relation to the direction of movement thereof, and in the direction of the supporting surface.
- the nozzle 41 is fed with pressure fluid via one or more conduits 42 formed, for instance, in thethickness of the wall 39.
- the or each conduit is connected to a pressure fluid source so that when they are supplied, the nozzle 41 delivers a fluid curtain directed towards the cushion supporting surface, thus reducing the gap via which the cushions run the risk of being supplied with fluid by the dynamic forward pressure, producing a constriction by a fluid diaphragm.
- the pressure fluid source can be (Figs. 4 and 6) a dynamic pressure pickup 43 with which the wall 39 is formed and which is connected to the conduit 42 via a conduit 44 comprising a divergent portion 44a.
- the pressure pickup 43 advantageously extends over the whole width of a cushion with which it is associated. Alternatively, it could be either wider or narrower and/or combined with an extra device for producing pressure fluid, such as, for instance, a series of injectors disposed in the conduit 44.
- the nozzle 41 can be fed by a compressor driven, for instance, by the same power source which either feeds pressure fluid to the cushions or propels the machine.
- an independent compressor 45 can be used controlled by the speed of movement of the machine, via the agency of a suitable device, such as that shown in Fig. 7.
- the compressor 45 is driven by an electric motor 46 whose supply circuit has a device 47 for adjusting the strength of the current supplied by a source 48.
- the device 46 can be formed by a rheostat whose slider 49 is actuated by a piston 51 subjected to the dynamic forward pressure of the machine on one of the piston faces 51a and to the opposing action of a spring on its other face.
- Conduits, as 53, for connection to atmosphere enable the piston to slide in its housing 54.
- the position of the piston 51 inside its housing 54 adjusts the position of the cursor 49 connected to one of the terminals of the source 48. In proportion as the machine moves more rapidly, the piston 51 compresses the spring to a greater extent, the result being an increase in the strength of the current supplied to the motor 46 and therefore in its speed.
- the gap at the front of the cushions is thus progressively reduced by the fluid curtain delivered by the nozzle 41, as the speed of movement of the machine increases.
- the scope of the invention would not be exceeded if the nozzle 41 were replaced by a plurality of orifices close enough together to form a substantially continuous curtain, or if a succession of curtains were to be disposed one after the other substantially parallel with one another.
- a cushion pressure control process for a high-speed ground effect machine having a cushion space which communicates with the ambient medium ahead of said machine through a frontally extending, controllable daylight clearance of variable effective gap width, said process comprising the steps of sensing the forward speed of said machine, and reducing said variable effective gap width as said speed increases thereby hindering ramming inflow of ambient medium through said daylight clearance and into said cushion space.
- a cushion pressure control system comprising means sensing the forward speed of said machine, daylight clearance control means for varying said effective gap width, and means interrelating said speed sensing means and said daylight clearance control means to reduce said effective gap width upon increase of said speed thereby hindering ramming inflow of ambient medium through said daylight clearance and into said cushion space.
- said daylight clearance control means comprise a frontally extending, movable wall member frontally bounding said cushion space and having an adjustably positionable free edge defining a variable effective gap width of said daylight clearance, an inner surface exposed to cushion pressure which urges said movable wall member in a direction to decrease said variable effective gap width, and an outer surface exposed to ambient dynamic pressure which urges said movable wall member in the opposite direction to increase said variable effective gap width; and means borne by said machine for countering the action of said dynamic pressure on said movable wall member.
- said dynamic pressure countering means comprises pressure operated servomotor means adapted to urge said movable wall member in said former mentioned direction to decrease said variable effective gap width.
- said daylight clearance control means comprises frontally extending variable-supply nozzle means for forming an adjustable fluid curtain frontally bounding said cushion spaced and defining an effective gap width which varies in accordance with the supply of said variable-supply nozzle means
- said interrelating means comprises variable pressure fluid supply means under the control of said speed-sensing means for delivering to said nozzle means a pressure fluid supply flow which increases as said speed increases.
- variable-pressure fluid supply means comprises a compressor discharging into said nozzle means, and electric motor driving said compressor, and means for varying the energization of said electric motor, said energization varying means being under the control of said speed sensing means.
- said energization-varying means comprises a rheostat with a resistance control slide
- said speed-sensing means comprises a dynamic pressure sensitive-member and a control linkage between said member and said slide.
Landscapes
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Vehicle Body Suspensions (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR169477 | 1968-10-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3601062A true US3601062A (en) | 1971-08-24 |
Family
ID=8655520
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US864685A Expired - Lifetime US3601062A (en) | 1968-10-10 | 1969-10-08 | Ground effect machines |
Country Status (3)
Country | Link |
---|---|
US (1) | US3601062A (fr) |
FR (1) | FR1585786A (fr) |
GB (1) | GB1286127A (fr) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3804197A (en) * | 1970-01-26 | 1974-04-16 | Bertin & Cie | Fluid-cushion-containing facility for ground effect machine |
US4422517A (en) * | 1977-05-04 | 1983-12-27 | Hammerschlag Peter G | Bag-positioned hinged seals for air cushion vehicles |
US5359941A (en) * | 1993-04-14 | 1994-11-01 | Genesis Iii, Llc | Transportation system, vehicle and method |
NL2000580C2 (nl) | 2007-04-11 | 2008-10-14 | Movares Nederland Bv | Systeem voor transport van personen of goederen. |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3190235A (en) * | 1962-06-26 | 1965-06-22 | Bertin & Cie | Vehicles associated to a guiding track |
US3272271A (en) * | 1963-06-21 | 1966-09-13 | Hovercraft Dev Ltd | Air cushion vehicles having movable cushion-containing walls |
US3291239A (en) * | 1963-05-24 | 1966-12-13 | Vickers Armstrongs Ltd | Air cushion borne vehicles |
US3486577A (en) * | 1965-10-21 | 1969-12-30 | Arthur M Jackes | Axial flow ground effect machine |
-
1968
- 1968-10-10 FR FR169477A patent/FR1585786A/fr not_active Expired
-
1969
- 1969-10-08 US US864685A patent/US3601062A/en not_active Expired - Lifetime
- 1969-10-10 GB GB49978/69A patent/GB1286127A/en not_active Expired
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3190235A (en) * | 1962-06-26 | 1965-06-22 | Bertin & Cie | Vehicles associated to a guiding track |
US3291239A (en) * | 1963-05-24 | 1966-12-13 | Vickers Armstrongs Ltd | Air cushion borne vehicles |
US3272271A (en) * | 1963-06-21 | 1966-09-13 | Hovercraft Dev Ltd | Air cushion vehicles having movable cushion-containing walls |
US3486577A (en) * | 1965-10-21 | 1969-12-30 | Arthur M Jackes | Axial flow ground effect machine |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3804197A (en) * | 1970-01-26 | 1974-04-16 | Bertin & Cie | Fluid-cushion-containing facility for ground effect machine |
US4422517A (en) * | 1977-05-04 | 1983-12-27 | Hammerschlag Peter G | Bag-positioned hinged seals for air cushion vehicles |
US5359941A (en) * | 1993-04-14 | 1994-11-01 | Genesis Iii, Llc | Transportation system, vehicle and method |
NL2000580C2 (nl) | 2007-04-11 | 2008-10-14 | Movares Nederland Bv | Systeem voor transport van personen of goederen. |
Also Published As
Publication number | Publication date |
---|---|
GB1286127A (en) | 1972-08-23 |
FR1585786A (fr) | 1970-01-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3586118A (en) | Ground-effect machines having improved guiding and propelling means | |
GB1275358A (en) | Aircraft control flap arrangement | |
US3601062A (en) | Ground effect machines | |
US3516361A (en) | Electromagnetically-propelled vehicle | |
GB1172442A (en) | Improvements in or relating to a Lift System for Aircraft | |
US3330221A (en) | Gas-cushion supported vehicles with drag inhibiting means for travelling on rails | |
BR9405609A (pt) | Veìculo de vÈo | |
US3587771A (en) | Ground-effect machines propelled by air or gas streams | |
US3276529A (en) | Ground effect vehicles | |
US3381627A (en) | Vehicles | |
GB854211A (en) | Improvements in or relating to vehicles for travelling over land and/or water | |
GB1134495A (en) | Improvements in air intakes for supersonic jet propulsion engines | |
GB1199314A (en) | Transportation System comprising a Track and a Ground-effect Machine Movable Along the Track | |
US3345098A (en) | Fluid track sanding system | |
GB1357872A (en) | Vehicle levelling systems | |
US3261419A (en) | System for controlling altitude and pitch in a ground effect vehicle | |
GB965748A (en) | Improvements in or relating to aerofoil members for aircraft | |
GB1249348A (en) | Ground-effect vehicles | |
US3400779A (en) | Flexible wall structure for air cushion vehicles | |
GB1241544A (en) | Improvements relating to gas-cushion load-supporting apparatus | |
GB1174938A (en) | Ground Effect Machines | |
US3610844A (en) | Electric current collector arrangement | |
US3695382A (en) | Devices for supplying the pressurized fluid cushions of a ground-effect vehicle | |
GB1296989A (fr) | ||
GB1111415A (en) | Improvements in or relating to gaseous cushion supported vehicles |