US 3362755 A
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Description (OCR text may contain errors)
Jan. 9, 1968 c s 3,362,755
CONVEYING DEVICE UTILIZING PRESSURIZED FLUID FLOW Original Filed Feb. 19, 1958 INVENTORI EL M62 F250 Mac/ 5 United States Patent 3,362,755 CGNVEYMG DEVHIE UTILIZING PRESSURIZED FLUID FLQW Elmer Fred MacQ, Willow Lane,
Vermilion, Ghio 44089 Continuation of application Ser. No. 716,243, Feb. 19, 1958. This application Aug. 23, 1962, Ser. No. 223,863
2 Claims. (Cl. 30229) The present application in a continuation of my copending application, Ser. No. 716,243, filed Feb. 19, 1958, which is a continuation-in-part of application Ser. No. 446,025, filed July 27, 1954, and now abandoned.
This invention relates to supporting devices and more particularly to supporting slides and conveyors wherein a fluid is utilized as a supporting film for a moving element.
It has been discovered that an object may be supported for free, substantially frictionless movement on a thin film fluid under pressure. To lift an object for free relative movement, fluid under pressure is provided over an an entire confined area of confrontation defined by cornplemental surfaces of a slide support and the obpect to be supported.
This discovery may be utilized by providing a slide support having a cavity and a foraminous wall defining a smooth open supporting surface. When a base surface of an object is placed in facial confrontation with the smooth slide support surface, fluid under pressure may be passed through the foraminous wall to lift the body. To accomplish this, fluid under pressure is introduced into the cavity. The fluid passes through the foraminous wall in a unform fashion over the entire surface. Thus, a thin film of fluid under pressure is formed between the object base surface and the slide support surface.
The film consists of a moving fluid which is constantly escaping around the periphery of the area of confrontation and being replenished by a fresh supply of fluid passing through the foraminous wall.
As fluid under pressure is passed through a restriction, a pressure drop is experienced. The greater the flow the greater the pressure loss, and conversely, the lower the fluid flow the lower the loss.
Thus, when fluid is passed through a foraminous wall having an area of confrontation on one side, a fluid film having load supporting characteristics will be formed over the area of confrontation. If the ratio weight of Object to be supported area of confrontation is high, the load supporting film will be of high pressure in a properly designed system so as to support the object. The flow of fluid on the other hand will be relatively low,
and hence the pressure drop will be low. Conversely, if the object is light, the flow and the pressure drop will be relatively high and the pressure of the film will be relatively low.
If the object is formed symmetrically, the film will be of uniform dimension. The filrn will, however, generally be of varying thickness and pressure since the weight of the object will not be symmetrically distributed. The heavy side of the object will be relatively close to the slide support and the film will be thin and of high pressure. The fluid flow on the heavy side will thus be low as will the pressure drop. Conversely, on the light side of the object, the film pressure will be low and the pressure flow and drop relatively high. Thus, even though the confronting surfaces are not precisely parallel, a thin lubricating and supporting film will be maintained. This feature of a properly designed system is known as automatic zone feedback compensation or simply as load zone compensation.
3,362,755 Patented Jan. 9, 1968 One of the principal objects of this invention, then, is to provide a slide support having a smooth, open surface and a foraminous wall through which fluid under pressure may be passed to form a lubricating and supporting fil-rn having load zone compensation.
In the present invention a slide support which provides such a thin film of supporting fluid by means of a porous wall is disclosed. It has also been discovered that an object may be supported and lubricated by a thin film provided by the object itself. This concept is disclosed in more complete detail in the copending application for patent Ser. No. 433,946, filed June 2, 1954, entitled Method and Apparatus for Providing Mobility, now abandoned in favor of continuation-impart application Ser. No. 737,969, filed May 26, 1958.
While it will be apparent to a mechanic skilled in the art that the principles of this invention are applicable to many devices in which relative unconfined movement along an open surface is desired, an amusement device is here set out as one embodiment of the invention and to disclose related improvements pertaining to this particular embodiment.
One of the objects of this invention is to provide a slide support in which a foraminous member having a source of fluid under pressure connected therewith forms a relatively frictionless surface for slidably supporting a mOV- ing element.
Another object of this invention is to provide a toy in which a foraminous wall is formed in turns and dips and is connected to a source of fluid under pressure for carrying an element thus simulating a roller coaster, ski slide, or other amusement device.
A still further object of this invention is to provide an amusement device in which a fluid foraminous floor is connected with a source of fluid under pressure, the upper surface of the floor having a film of fluid thereon for supporting in a relatively frictionless manner an individual having flat bottom skis or runners on which to stand during skating movements over the floor.
Another important object of this invention is to provide a conveyor wherein an inclined wall is permeable to allow the passage of fluid conducted thereto from a source of supply, thus establishing the film of fluid between the wall and a tray, belt, or a series of interconnected trays traversing the surf-ace of the inclined wall.
The embodiments of this invention include a wall of foraminous material capable of allowing the restricted passage of fluid therethrough in such a manner that a cooperating device such as a tray or pan is supported free of the wall on a relatively frictionless film of fluid. The foraminous wall is incorporated in a structure having a plenum chamber or duct in communication with the Wall. Air, water, or other fluids may be utilized as the supporting medium depending on the desired characteristics. The foraminous wall is formed to the desired shape to guide and support a moving body throughout a path of either a straight incline or dips and curves or over a horizontal straight path.
The structure of the foraminous or permeable wall is such that as the fluid flows therethrough, a pressure drop results even if the flow is unrestricted at the surface by the presence of an object to be supported by the load supporting film. At this condition the residual pressure at the surface would be less than the supply pressure. If a portion of the permeable wall is covered by a tray, flat plate, belt, or similar device, the flow through the wall would be restricted in that area with the result that the pressure drop through the Wall would be reduced thus producing a residual pressure between the wall and the plate approaching that of the source of supply. Accordingly, con
siderable loads may be placed on trays or belts which are supported out of contact with the slide with the only resistance to movement being the very small friction produced by the viscosity of the fluid being utilized. The usefulness and novel eflects which can be achieved by utilizing this invention result in articles of manufacture of unusual nature.
Accordingly, it is one of the most important objects of this invention to provide a structure in which a wall of foraminous material regulates the flow of fluid over an area to establish a supporting film of the fluid on which elements may be moved with relatively little force required.
Other objects and advantages, more or less ancillary to the foregoing, and the manner in which all the various objects are realized will appear in the following description, which considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.
In the drawings:
FIGURE 1 is an elevational view of a ski slide embodying my invention;
FIGURE 2 is a sectional view taken along line 22 of FIGURE 1;
FIGURE 3 is a view similar to FIGURE 2 showing a modified form of the ski slide;
FIGURE 4 is a sectional view of a skating floor;
FIGURE 5 is a side view of a runner for operation on the skating floor;
FIGURE 6 is a sectional view taken along line 6-6 of FIGURE 5 FIGURE 7 is a sectional view of a conveyor taken along line 77 of FIGURE 8;
FIGURE 8 is a sectional view taken along line 8-8 of FIGURE 7; and,
FIGURE 9 is a View similar to FIGURE 8 of a modified form of the conveyor.
The invention is incorporated in a ski-slide type of device shown in FIGURE 1 wherein the frame of the slide is designated by the numeral I0. A track 12 is supported by the frame 10 in the desired configuration as required by the type of toy design. In FIGURE 1 the toy is illustrated as a ski slide but it is understood that it may also be in the form of a roller coaster utilizing turns and additional dips. This slide apparatus may be used wherever it is desired for an object to move along a predetermined path, the only force required for imparting motion to the object being that of gravity. The frame 10 serves as a housing having a relieved area which together with the slide 12 defines a cavity 14 in such a manner that a Wall of the slide 12 is exposed to the interior of the cavity 14. Supporting struts 16 are disposed between the slide 12 and the frame 10 to strengthen the slide 12 in order to carry the loads imposed thereon. The struts 16 are perforated to allow inter-communication between the sections of the cavity 14 and are so arranged that they do not cover an appreciable part of the surface of the slide 12.
The floor 12 must be sufliciently foraminous to permit fluid under pressure to flow from the cavity 14 through the floor 12 to the outer surface of the floor in order that a film of fluid under pressure may be formed at any location on the floor. Thus, when an object being supported is moved across the floor 12 in translational movement, the supporting fihn is created wherever the object is. To accomplish this there must be a plurality of small holes or pores in the body. A sintered material such as a sintered bronze is an excellent example of a workable material since relatively uniform porosity is provided throughout the entire floor or track. A plurality of holes may be drilled or formed in an otherwise solid material to provide the same effect. The term foraminous has been selected because it is a term which defines all types of porosity operable in this invention including both orifice and permeable types of restrictions to obtain the desired load zone compensation. The degree of porosity will vary widely according to the fluid, the weight and size of the object being supported, and other variables.
To obtain proper load zone compensation and the above-mentioned desirable operating characteristics with an optimum overall system, the foraminous wall and confronting surfaces must be carefully engineered. To provide adequate load zone compensation and a safe value of minimum load supporting film thickness while yet maintaining a low rate of fluid flow under all operating conditions the following relationship should be maintained:
p /p is from 1.25 to 5.0 where p is the supply pressure,
p; is the average film pressure of the load supporting film in the case of a porous surface or the load supporting film pressure at the orifice exit in the case of other means of zone compensation.
Many operating and design variables such as orifice size and roughness, wall thickness, fluid viscosity, temperature, etc. must be properly considered so as to provide the safe minimum load supporting film thickness generally under 0.005 inch and normally about 0.001 inch.
The foraminous support surface may be porous (such as sintered bronze) or may contain other forms of load zone compensation such as an orifice-pool configuration or it may simply contain a series of very small orifices drilled, or punched or otherwise formed. Examples of various types of foramina may be found in the copending application for patent Ser. No. 643,665; filed Mar. 4, 1957 for a seal, now Patent No. 2,907,594, issued Oct. 6, 1959. In all cases, however, the ratio p p is greater than 1.25.
Expressed in another way, the load zone compensation should provide an average pressure drop of about /5 to Vs as fluid is passed from the source of supply to the load supporting film when the device is in operation. Thus, the average pressure in a load carrying film will be no more than /5 and at least /s of the pressure of the supplied fluid in the chamber or cavity 14.
A conduit 20 is connected to the frame 10 to open into a fluid accumulator 22 through aperture 18. A pump 24 compresses the air in the accumulator 22 for subse quent discharge through the conduit 20 and into the cavity 14. A valve 26 in the conduit 20 controls the flow of fluid therethrough and may be remotely actuated by a trip device 23 at the starting point of the ski slide. An alternate fluid supply may be connected to conduit 20 by a conduit 30. A check valve 32 in conduit 30 prevents the loss of fluid when pump 24 is being used as the compressor.
A control 34 such as a cam and lever arrangement positions the end of the slide 12 and the portion of the frame forming the cavity thus controlling the path of flight of an object which has just traversed the slide. In FIGURE 2 a toy skier 36 is shown having skis 38 aflixed thereto for confronting the upper surfaces of the slide 12. Slide 12 has upwardly extending portions 40 having their inner surfaces arranged to discharge fluid laterally against the skis 38 thus maintaining the skis 38 spaced from the portions 40. In this Way the skier 36 is guided and supported along the slide 12.
In FIGURE 3 a slide 12 is shown having a center guide 42 in addition to the portions 40 for maintaining the direction of travel of a skier. The foraminous material forming the slide 12 has its faces sealed which are not opened to the cavity or do not function with the object to be supported and guided. This seal may be accomplished by portions of the frame including a sealing lip 44 which prevents the loss of fluid from surfaces having no function. Burnishing, tape, paint, cement, or other materials may also be applied to the permeable material to regulate the areas from which the fluid is to be discharged.
The ski slide 12 is adaptable for use as a slide for sporting events out of season since the slide 12 and the skis 38 may be proportioned to support the weight of a man and provide conditions even more frictionless than snow or ice.
A skating floor or rink 46 is shown in FIGURE 4, the
floor 46 being formed from foraminous material which will allow fluid to permeate to the upper surface thereof.
A base 48 has a fluid-tight lower wall and sides for supporting the floor 46 with a cavity 50 adjacent the lower face thereof for receiving fluid from an inlet 52 which is connected to a source of fluid under pressure which may take the form of a pump and accumulator, water supply system, overhead tank, or other system capable of continuously supplying fluid at a nominal pressure. A plurality of struts 54 support the floor 46 and the load carried thereby.
To better illustrate the principles embodied in the device of FIGURES 4 through 6 dimensions of a relatively large embodiment of this invention are provided. The foraminous floor 46 in a a skating rink may, for example, have a dimension of 10 feet by 20 feet. A fluid such as water is supplied to the cavity 50 under the foraminous floor 46 to provide the desired fluid under pressure to create the film. In this example the water would be supplied under a pressure of approximately 5 pounds per square inch, and it will flow through the foraminous floor 46 at the rate of about 4 gallon per minute per square inch when the rink is not in use. When the rink is in use, the flow, of course, will be reduced in those areas where skaters are present because, as has been previously described, the pressure drop will decrease and therefore the flow will reduce. In this embodiment the flow is preferably circulated by a built-in pump.
The total pressure applied against the foraminous floor from the cavity side is approximately pounds per square inch. In the present example, as in the other embodiments of this invention, sintered bronze is a suitable material for construction of the foraminous floor. The floor 46 in the by 20 foot embodiment would be approximately one and one-half inches in thickness. In this instance the strut supports 54 would be about one-quarter inch in diameter and one-sixteenth inches in length and would be provided about the foot apart to reinforce the floor.
Sizes of skates such as those shown in FIGURES 5 and 6, vary with the size of the skater. As an example, a skater having a weight under 100 pounds would use a pair of skates each of which has approximately 40 square inches of surface and each of which would be approximately 4 by 10 inches in dimension. A skater of from one hundred to two hundred pounds would require skates having about 80 square inches each. Such skates can suitably be constlucted 5 by 16 inches in dimension.
The skate which is used on the floor 46 is illustrated in FIGURES 5 and 6 in which a flat plate 56 having a plane bottom on which the user stands. The bottom of the skate may be rigid or flexible. A resilient edging 58 is mounted on the periphery of the plate 56 and functions as an edge to propel and brake the skater when the skate is tilted. This edge also functions as a bumper to prevent damage to another skate and the permeable floor or to prevent injury to the body of a wearer. The flat undersurface plate 56 when confronting the floor 46 and approximate thereto is supported by the film of fluid which is distributed over the surface of the floor by the permeable nature of the material and the cavity acting as a plenum chamber beneath the lower surface of tthe floor 46. The fluid pressure and the area of the plate 56 are adjusted to support the weight of the individual standing on the plate 56.
In FIGURES 7, 8 and 9 a conveyor is shown embodying the invention disclosed herein having a slide 60 formed from a foraminous material, the slide 60 being sloped to allow the force of gravity to produce translation of the object to be conveyed. A fluid-tight frame 62 supports the slide 60 and forms a cavity 64 for receiving fluid under pressure to be discharged through the slide 60. A plurality of struts 66 support the slide 60 and the load thereon, the struts 66 being perforated with relatively large holes or slots to allow intercommunication between the sections of the cavity 64. A pump 68 provides the fluid under pressure which is pressurized in an accumulator 70 and piped to the cavity 64 through a conduit 72 having a control valve 74 therein for regulating the flow of fluid through the cavity. An alternate fluid supply may be connected to conduit 72 by a conduit 73. The load to be conveyed is placed on a pallet 76 which has bottom and side surface conforming to the surface of the slide 60. The pressure of the fluid in the cavity 64 produces flow through the slide 60 and develops a continuous film of fluid intermediate the slide 60 and the pallet '76 which is relatively frictionfree. Since the friction is so small a slight inclination in the slide 60 is suflicient for the pallet 76 to gravitate therealong with no external urging required. The pallet 76 may take the form of an individual tray, a series of connected trays, or of a continuous belt which is driven by an external means in either a horizontal or inclined direction.
In FIGURE 9 the slide 78 is curved to provide a concave upper surface for carrying a concave tray or belt 80. Slide 78 is formed of a permeable material and supports the tray 80 in the same manner as the slide 60 supports the tray 76. The arcuate slide 78 and the correspondingly shaped tray 80 is particularly adapted for carrying small articles or granular material which would not repose on a fiat tray. Further, the tray 80 is self-centering since the forceof gravity would tend to hold the tray 80 in the lowermost area of the slide 78. This shape is particularly desirable in the operation of a conveyor belt since any material carried thereon would not tend to be lost from the belt surface. It is understood that slides of other shapes are contemplated as might be required for special purposes and would fall within the scope of this invention.
The runners, pallets, belts, and trays which form the movable load supporting members confronting the permeable wall may be of either rigid or flexible material to conform to the supporting surface or accomplish a function required by the object being carried. The embodiments of this invention are illustrated in general as toys or amusement devices. However, it is contemplated that essentially these same structures and principles are usable in large scale and in industrial applications, for example, the conveyor system.
A device has thus been described which has a foraminous wall with a smooth, open outer surface and an inner surface communicating with means for supplying fluid under pressure to provide a zone compensated supporting and lubricating film of fluid between the outer surface and a complemental surface on an object to be supported when the object is placed with such outer and complemental surfaces in face-to-face relationship.
Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or confining; and that various rearrangements of parts and modifications of design may be resorted to without departing from the scope or spirit of the invention as hereinafter claimed.
What is claimed is:
1. A fluid lubricated conveying device for facilitating movement of an object comprising in combination a foraminous wall, said wall having a bottom surface, an upper, object-confronting surface, and upwardly extending side Walls extending above said object confronting surface, said side Walls and said object-confronting surface defining a channel-shaped conveying path for said object, means for suppling fluid under pressure to said wall to produce a supporting film of fluid between the object and said object-confronting surface by fluid flow through said wall and to laterally center the object in said channel-shaped conveying path by fluid flow through said side walls, and means on at least the portion of the wall including said bottom surface and said object confronting surface for restricting the rate of fluid flow therethrough to produce an average pressure drop thereacross in the absence of an object on said object-confronting surface.
2. A lubricated conveying device for facilitating movement of an object comprising in combination a channelshaped foraminous support, said support having a bottom surface, an upper object-confronting surface, and opposed side walls extending above said object-confronting surface, a forarninous center guide between said side Walls and coextensive therewith, said side walls and said center guide having formaiuae arranged to discharge fluid laterally against an object disposed contiguous to said object confronting surface, means for supplying fluid under pressure to the bottom surface of said support and to said side walls and said center guide so that a fluid film is formed between the object and said object confronting surface and so that the object is centered between said guide and said side walls, and means on at least the portion of the support forming said object confronting surface to produce an average pressure drop thereacross even in the absence of an object on said object confronting surface.
References Cited UNITED STATES PATENTS 756,600 4/ 1904 Dodge. 1,971,853 8/1934 Ihlefeldt 3023l X 2,174,716 5/1938 Bethell 27256.5 2,538,972 1/1951 Magnan-i. 2,678,237 5/1954 Allander et a1 302-31 2,708,602 5/1955 Galle 302-29 2,805,898 9/1957 Willis 30229 F. BARRY SHAY, Primary Examiner.
RICHARD C. PINKHAM, E. C. BLUNK, F. B.