US 3754617 A
The space between two bodies moving relatively to each other is partitioned in order to form a plurality of overpressured or underpressured fluid cushions. The partitioning is provided by a waffled flexible sheet fixed to one of the two bodies whereby to confine, jointly with the other body, the space therebetween, while at the same time subdividing the same into a plurality of contiguous cells separated from one another by the upstanding waffles on said waffled sheet. The cells are nested into one another, with central cells surrounded by peripheral cells.
Description (OCR text may contain errors)
United States Patent Duthion et al.
DEVICE FOR PARTITIONING A SPACE BETWEEN TWO BODIES IN RELATIVE MOTION TO EACH OTHER inventors: Louis Duthion, Paris; Michel Jules Jacquot, Suresnes; Charles Gustave Amicel, Carrieres sur Seine; Robert Augustin Chaube, Jumeauvilie sur Mauie; Francis Marie Jean Crolx-Mnrie, Viry Chatilion, all of France Assignee: Bertin & Cie, Plaisir, France Filed: Feb. 23, 1971 Appl. No.: 117,891
Foreign Application Priority Data Mar. 27, 1970 France 11215 US. Cl 180/121, 180/124, 180/125 Int. Cl. B60v 1/16 Field of Search 180/121, 124, 118,
References Cited UNITED STATES PATENTS 8/1965 Dobbertien 180/ Aug. 28, 1973 3,245,487 4/1966 Mackie 124 3,246,711 4/1966 Snoeyenbos 180/124 X 3,251,431 5/1966 Mackie 180/124 3,295,621 1/1967 Deeley, Jr. et a1 180/124 3,313,367 4/1967 Swedburg 180/124 X 3,318,406 5/1967 Scheei 180/124 X 3,375,893 4/1968 Mackie. 180/124 3,385,390 5/1968 Guienne.... 180/118 X 3,513,934 5/1970 Crowley"; 180/124 Primary Examiner-Benjamin Hersh Assistant Examiner-Leslie J. Papemer Attorney-Brufsky, Staas, Breiner & Halsey  ABSTRACT 10 Claims, 21 Drawing Figures Patented Aug. 28,1973 3,754,617
5 Sheets-Sheet 2 Patented Aug. 28, 1973 5 Sheets-Sheet 5 Patented Aug. 28, 1973 5 Sheets-Sheet 4 Patented Aug. 28, 1973 5 Sheets-Sheet 5 DEVICE FOR PARTITIONING A SPACE BETWEEN TWO BODIES IN RELATIVE MOTION TO EACH OTHER The present invention relates to the partitioning of the space between two bodies which are movable relatively to each other without, or with very little, mutual friction, in such manner as to subdivide the space into a plurality of individual chambers or cells inside which are established overpressures and/or underpressures with respect to the environment for the purpose of generating lift or guiding forces. The invention finds particularly interesting applications in the field of groundeffect machines which travel over a surface with an interposed cushion of fluid at positive and/or negative pressure, the very plurality of such cushions enabling the stability of the system to be improved especially if the cushions are supplied independently.
The present invention relates to a partitioning device basically comprising a preferably flexible waffled sheet having a cellular appearance, which is fixed to one of the two relatively moving bodies whereby to bound, jointly with the other, the space therebetween while at the same time subdividing the space into a plurality of preferably contiguous cells or chambers which are partitioned from one another by the protruding waffles on said waffled sheet. Preferably, the cells extend over a relatively large area and the waffles over a relatively small area.
The waffling can be produced for example on a flexible sheet which may originally have been flat and continuous, either by a continuous preforming process or by a transient process by inflating the sheet locally to produce the waffles or ribs. Preferably, the bottoms of the cells of the waffled sheet are each provided with a reinforcement in the form of a metal platelet, or the like, applied against the bottom and clamping it against a rigid pressure plate, the ribs or waffles being on the other hand free and retaining their flexibility. The waffled sheet may be secured at the level of the bottoms of the cells, for instanceby a bonding process or by riveting the platelets to the pressure plate through the sheet.
The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.
In the drawings: I
FIG. 1 is a plan-view showing of the underneath of a ground-effect platform devised according to a possible embodiment of the present invention FIG. 2 is a sectional view on an enlarged scale through the line "-11 of FIG. I
, FIGS. 3 to 6 are corresponding partial sectional views on an enlarged scale, of alternative embodiments FIG. 7 is a plan-view showing of the top of a system reversed with respect to that of FIG. I
FIG. 8 is a sectional view on the line VIII-VIII of FIG. 7
FIG. 9 is a fragmental plan view of another embodiment according to the invention FIG. 10 is a sectional view on the line XX of FIG. 9
FIG. 11 is an axial sectional view, on the line XI-XI of FIG. 12, of a fluid bearing;
FIG. 12 is a cross-section taken through the line XII- -XII of FIG. 11;
FIGS. 13 and 14 are views in partial section of two possible embodiments of a structural detail FIG. 15 is a partial showing, as viewed along the arrow F of FIG. 16, of a ground-effect machine devised accordingto still another enTbodiment of the invention:
FIG. 16 is a section through the line XVIXVI of FIG. 15
FIGS. 17, 18 and B9 are partial views corresponding to FIG. 15, showing alternative possible cell shapes and distributions 7 FIG. 20 is a fragmental plan-view showing of the underneath of a ground-effect machine devised according to yet another possible embodiment of the invention and FIG. 21 is a section taken through the line XXI-XXI of FIG. 20.
In the embodiment shown in FIGS. 1 and 2, a groundeffect machine platform 1, used for transporting a burden 2 in the illustrated example, travels above a surface 3 with twenty-five interposed fluid cushions 4 arranged in square formation.
In accordance with the present invention, these cushions 4 are confined by a flexible sheet 5, made of plastic or rubberized fabric for example, formed with ribs or protrusions 6. which give it a cellular appearance. Against the bottoms 7 of these cells or chambers are applied possibly metallic platelets 8 which may be round, polygonal or star-shaped. The sheet 5 is clamped, on the one hand, between the platelets 8 and a pressure-plate 9 integral with the rigid structure of platform 1 and, on the other, along its periphery 14 against a flange 15 provided along the perimeter of platform 1. The platelets 8 are secured to pressureplate 9 by hollow rivets 10.
Obviously, the flexible sheet 5 could be otherwise secured to pressure-plate 9, for instance by bonding of the bottoms 7 and the periphery l4.v
In addition to their securing role, the hollow rivets 10 serve to supply pressure-fluid to the cushions 4 from a distributor conduit 11 connected to a delivery union l2. Passages or holes 13 are likewise provided through pressure-plate 9 in registry with the network of ribs 6 on sheet 5.
As will readily be appreciated, these ribs are accordingly inflated and caused to project towards the surface 3, thereby laterally confining the individual cushions 4 after the fashion of square skirts, there being a small terminal clearance with respect to the surface 3 that provides a leakage gap from the cushions 4 for the fluid supplied through hollow rivets l0.
As shown in FIG. 3, the holes 13 provided through pressure-plate 9 for inflating the ribs 6 could be dis pensed with and recourse had to holes 16 formed through sheet 5 instead. This would require a degree of stiffness in the material of which the sheet is made in order to prevent total flattening of the ribs when the cushions 4 are set under pressure.
Use may be made of elastic compressible elements such as beads l7, made of rubber or cellular material for example (see FIG. 4), in order to ensure protrusion of the ribs 6, thereby to assure a partitioning of the individual cushions 4 that is permanent and exists before the cushions 4 are set under pressure. In an alternative embodiment (not shown) the height of the beads 17 could be made smaller than that of the protrusions in order not to hamper the flexibility of the latter.
Instead of being effected directly, the supply to cushions 4 could be made from the ribs 6, as shown in FIG. 5, in which case the cell bottoms 7 would be secured by solid screws 18 instead of by hollow rivets.
A suspension effect may be achieved by an elastic mounting of each platelet 8, to impart the faculty of inclination, by meansof a connection using a rod 19 and spring 20 and an interposed layer 21 of a deformable material such as neoprene, thereby allowing the system to adapt to large irregularities on the surface 3.
In all the embodiments hereinbefore described, the cushions or cells 4 and the ribs 6 are supplied either directly or indirectly but invariably from a common pressurized delivery conduit 11.
However, it may occasionally be useful to have a separate supply for the cells 4 and a separate supply for the ribs 6. A notable case in point would be when the cells have to be set under negative pressure in order to exert a suction effect, at the same time as the ribs are maintained at an overpressure in order to cause them to protrude.
Such an arrangement is illustrated in FIGS. 7 and 8, in which the general layout is reversed platform 1 is beneath the surface 3. The delivery conduit 11a which has port in the cells 4 via the hollow rivets 10 is connected at 120 to a positive or negative pressure source, whereas the delivery conduit 11b which has port in the ribs 6 via the holes 13 is connected at 12b to an inflating source.
Two alternative modes of operation may be envisaged, depending on whether 11a is at positive or negative pressure. In the former case, pressure-fluid cushions are formed in the cells 4 the platform 1 is stationary and constitutes a fluidized area, i.e. an area delivering fluid under pressure and over which travels the surface 3, which may be a conveyor belt, a sheet of metal, or the like. In the latter case, the surface 3 could be the ceiling of a room or the underface of a suspended track along which the platform 1 travels and is supported through the agency of layers of a fluid at a pressure below atmospheric pressure, as described in Faure U.S. Pat. No. 3,515,073. In this latter case, the platform 1 includes means (not shown) for supporting the load to be transported.
The above-described arrangements may alternatively be associated to provide the one illustrated in FIGS. 9 and 10, in which the platform 1 is positioned between two substantially parallel surfaces 3--3. In this case the waffled sheet 5 may extend continuously over both faces of platform 1.
As shown in FIGS. 11 and 12, which illustrate an application of the invention to a fluid bearing, the surface 3 may be a surface of revolution, reference numerals l designating the bearing proper and 3 the surface of the shaft rotating therein. Application of the ground effect for devising a fluid bearing is already known through Bertin U.S. Pat. No. 3,140,753 and it is accordingly unnecessary to give a detailed description of the manner of operation thereof.
In the embodiments hereinbefore described, the ribs 6 have invariably been indicated as being supplied under pressure for their inflation. This is by no means essential, however, and it would be equally feasible to resort to ribs possessing the desired shape by design, whether hollow as shown at 6a in FIG. 13 or solid as shown at 6b in FIG. 14.
Reference is now had to FIGS. 15 and 16 for a showing of a ground-effect machine 1 travelling opposite a surface 3, which may be a vertical surface of a low wall or of a central extension, with interposed fluid cushions in accordance with a now classic arrangement described in Bertin et al. U.S. Pat. Nos. 3,190,235, 3,330,384, 3,332,36l and 3,347,170. Clearly visible in the figures are central cushions 4a which are supplied with pressure-fluid directly and which are surrounded by peripheral cushions 4b supplied with the leakage fluid from the central cushions, in accordance with a likewise known arrangement. Obviously, it would be possible alternatively to supply the peripheral cushions 4b with fluid pressure directly from the conduit 11a or from an independant source at a possibly different pressure.
These cushions are confined by a flexible sheet 5, made of a plastic or rubberized fabric for example, and formed with ribs or protrusions 6 which give it a cellu lar appearance. Against the bottoms 7 of the cells or chambers are applied platelets 8, made of metal say, which are in the shape of rectangles in the case of the central cells 4a and of rectangular crowns in the case of the peripheral cells 4b. Sheet 5 is clamped, on the one hand, between platelets 8 and a pressure-plate 9 integral with the rigid structure of the machine platform 1 and, on the other, along its periphery 14, against a flange 15 provided along the perimeter of platform 1. Hollow rivets 10 secure the central platelets 8 to the pressure-plate 9, and the peripheral platelets are secured by means of screws 18.
Manifestly, the flexible sheet 5 could be fixed in different manner to pressure-plate 9, an example being by bonding of the bottoms 7 and the periphery 14.
In addition to their securing role, the hollow rivets 10 serve to supply pressure-fluid to the cushions 40 from a distributor conduit 11a connected to a delivery union 12a. Passages or holes 13 communicating with a further distributing conduit 11b are likewise provided through pressure-plate 9 in registry with the network of ribs 6 on sheet 5.
It will readily be appreciated that the ribs 6 are accordin'gly inflated and caused to project toward the surface 3 to laterally confine the individual cushions 4 after the fashion of square skirts, there being a small terminal clearance with the surface 3 whereby to provide a leakage gap for the fluid from cushions 4 supplied through hollow rivets 10.
It is to be noted that only the central cells 40 are supplied through conduit lla, in contrast to the peripheral cells 4b which are not, the inflatable ribs 6 performing the function of a labyrinth seal.
In cases where the pressures in cushions 4a and 4b are not equal, the ribs 6 can be inflated at different pressures. For instance, the pressure in the peripheral ribs may be lower than the pressure in the ribs boundingthe central cushions.
Clearly, instead of causing an overpressure to prevail in the central cells 40, the latter could be set under negative pressure by connecting 12a to a source of pressure lower than atmospheric pressure, in which case the platform of machine 1 would act like a suction device. Similarly, the system hereinbcfore described could function with respect to a substantially horizontal surface 3, either above the latter in which case an overpressure supply could be used, or beneath it in which case an underpressure supply would be used.
An arrangement of central and peripheral cells is by no means essential, as shown in FIG. 17 which illustrates a system of juxtaposed rectangular cells arranged in a plurality of rows and staggered from one row to the next. The result of this stagger is that the crest lines of the inflated ribs 6 meet in threes instead of in fours if there were no stagger, thereby making it easier to negotiate possible obstacles.
In the embodiment shown in FIG. 18, the cells 40 are square and arranged in staggered formation, additional ribs 60 being provided to interconnect these cells and to confine additional cells 4b having an octogonal shape in plan view. The cells 4b may be supplied with fluid from the leaks out of the cushions 4a, or from orifices 26 connected to a suitable fluid source.
In the alternative embodiment illustrated in FIG. 19, the central cushions 4a are again rectangular and surrounded by a peripheral labyrinth 6 whilst being at the same time separated by labyrinth partitions 6'.
The present invention further provides for a subdivision into a plurality of subsystems in the various arrangements hereinbefore described. FIGS. 20 and 21 show two such subdivisions separated by an intermediate passage 25 communicating with the atmosphere. These two subsystems are supplied independently of each other.
1. A ground-effect type bearing device having a structure with a rigid pressure plate integral therewith, movable relatively to a body with the interposition of a space between said structure and said body, said device comprising:
a flexible sheet extending adjacent to said rigid pressure plate,
a flange extending along the periphery of said structure and designed for clamping said flexible sheet to said rigid pressure plate,
a plurality of platelets. positioned inside said peripheral flange and designed for further clamping said flexible sheet to said rigid pressure plate, the sides of said platelets being spaced from and substantially parallel to the sides of each other and to the sides of said flange, said flexible sheet forming in the intervals between said spaced sides protrusions bulging towards said body-and in free communication with each other, said protrusions partitioning said space into a plurality of contiguous chambers in generally chessboard pattern, first source of fluid under pressure and a second source of fluid at a pressure different from ambient pressure, both positioned on the side of said pressure plate opposite to said flexible sheet and platelets,
means extending across said pressure plate for communicating said protrusions with said first source whereby to maintain the same in said bulging configuration, and
further means extending across said pressure plate,
said flexible sheet and said platelets for communicating at least some of said chambers with said second source, whereby to maintain said space at a pressure different from ambient pressure for the development of a ground effect relationship between said structure and said body.
2. Device as claimed in claim 1, further comprising solid elements of compressible resilient material housed in said protrusions and designed for maintaining the same in bulging configuration.
3. Device as claimed in claim 1, further comprising a layer of deformable material sandwiched between said pressure plate and the clamped portions of said flexible sheet, and a rod-and spring system extending between said platelets, and said pressure plate and across said flexible sheet and said layer, for resiliently urging said platelets towards said pressure plate, thereby compressing said layer.
4. Device as claimed in claim 1, wherein the portions of said flexible sheet which are clamped to said rigid pressure plate by said flange and by said platelets, are substantially co-planar with each other and with the bottom of said chambers opposite said body.
5. Device as claimed in claim 1, wherein said protrusions form together a generally crosslike pattern with substantially straight portions.
6. Device as claimed in claim 5, wherein said protrusions are of substantially the same amplitude.
7. Device as claimed in claim 6, wherein said chambers are alined along substantially parallel straight rows and are staggered from one row to the next adjacent row.
8. Device as claimed in claim 7, wherein said chambers are further alined along further substantially parallel straight rows at an anglewith said first-mentioned rows, and are further staggered from one of said further rows to the next adjacent one of said further rows.
9. Device as claimed in claim 8, wherein said rows are substantially perpendicular to each other, and said chambers are of substantially square shape and are positioned at the intersections of said rows.
10. Device as claimed in claim 9, further comprising additional chambers of substantially octogonal shape staggered between said square chambers.