Transporter For Use In Water

Abstract

This invention relates to a submersible transport apparatus comprising a flexible hollow generally toroidal envelope having inner and outer surfaces, said inner surface being extrovertible toward said outer surface at the leading end of the apparatus and said outer surface being simultaneously introvertible toward said inner surface at the trailing end of the apparatus, and transport means for displacing said envelope axially through a fluid medium, said transport means including a plurality of guide elements with endless surfaces engageable and movable with the walls of said envelope for guiding said walls in the direction of travel of the envelope in said fluid medium and for imparting to the envelope a traction, which together with the frictional forces acting on the envelope as a result of movement through the fluid medium causes said envelope to develop a combined sliding and rolling motion with respect to the external fluid medium.

Parent Case Text

This is a continuation-in-part of application Ser. No. 738,746, filed May 8, 1968 and now abandon.

Description

This invention relates to a transporter for use in water.

It has been proposed to transport bulk goods such as, for example, fuel oil, liquid chemicals or the like, by water in flexible containers formed of suitable plastic materials and designed to be towed. With such an arrangement, however, the movement of the container through the water encounters the full viscous resistance to motion of the water itself and this of necessity is reflected in increased costs of transportation and wear and tear of the container.

It is an object of the present invention to provide an improved water transporter in which the disadvantages referred to above are substantially reduced.

According to the present invention, there is provided a submersible transport apparatus comprising a flexible hollow generally toroidal envelope having inner and outer surfaces, said inner surface being extrovertible toward said outer surface at the leading end of the apparatus and said outer surface being simultaneously introvertible toward said inner surface at the trailing end of the apparatus, and transport means for displacing said envelope axially through a fluid medium, said transport means including a plurality of guide elements with endless surfaces engageable and movable with the walls of said envelope at angularly spaced locations about the axis of the envelope for guiding said walls in the direction of travel of the envelope in said fluid medium and for imparting to the envelope a traction, which together with the frictional forces acting on the envelope as a result of movement through the fluid medium causes said envelope to develop a combined sliding and rolling motion with respect to the external fluid medium.

In a preferred embodiment, the said flexible torus is arranged to surround a rigid cylindrical container having sealed ends and being formed with a coaxial bore through which pass the inner walls of the flexible torus, said rigid container being provided with radially directed pulleys on either end to guide, in operation, the extroversion of the torus with respect to the container.

Preferably said torus is provided with a harness which is connectable to an appropriate towing mechanism.

The harness may comprise looped cables arranged to pass over the torus and through the axial passage thereof.

Means may be provided for driving said pulleys.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIGS. 1a to 1e respectively illustrate the requisite steps in the construction of a torus to be used as a transporter in accordance with the present invention,

FIGS. 2 and 2b are, respectively, longitudinal sectional and plan views of the inlet of the torus of FIGS. 1a to 1e.

FIG. 3 illustrates schematically a side elevation of a first form of bulk goods transporter in the form of a torus shown in FIGS. 1a and 1e and in accordance with the invention,

FIG. 4 is a schematic longitudinal partially sectioned elevation of a second form of bulk goods transporter in accordance with the invention,

FIG. 5 is a partially sectioned view of the transporter shown in FIG. 4 taken along the line V--V,

FIG. 6 is a perspective view (partially broken away) of a further form of transporter in accordance with the present invention,

FIG. 7 is a perspective view (partially broken away) of a further form of transporter in accordance with the present invention,

FIG. 8 is a cross sectional elevation of the transporter shown in FIG. 7 taken along the line VIII--VIII,

FIG. 9 is an end view of the transporter shown in FIG. 7,

FIG. 10 is a cross sectional view of a portion of the transporter shown in FIG. 9, and

FIG. 11 is an exploded view while FIGS. 12 and 13 are sections illustrating another embodiment of the invention.

Referring first to FIGS. 1 and 2 of the drawings, there is shown schematically a method of constructing a torus, the principle of the construction being adapted for making a transporter in accordance with the present invention. As seen in FIG. 1a the torus is formed of two thin-walled flexible tubes 1 and 2 which are inserted one inside the other and which are substantially of equal length and diameter. The tubes are so arranged that one end of the outer tube 1 projects slightly beyond the corresponding end of the inner tube 2. The two tubes 1 and 2 are wholly bonded to each other except for a region which includes an inlet valve 3 and which will be described below. In this way the structure now forms essentially a double-walled tube with single layer ends. These two ends of the double-walled tube are now turned over on themselves and are bonded to each other so that the whole structure now constitutes an empty toroidal envelope, a portion of which is shown in FIG. 1b. Water or other fluid is injected into this envelope through the inlet valve 3 so as to deform the flexible walls of a torus 4 so formed, (see FIGS. 1c and 1d) the torus 4 having inner walls which will herein be referred to as a "core" 5.

In order to illustrate the mode of movement of the torus reference is made to FIG. 1e where the torus 4 is considered as having been inserted in a conduit 6 and a suitable pressure difference is established on either side of the torus 4 which would, in fact, occur in the case of a transporter towed through water, the motion of the torus 4, as indicated by arrows, takes place, this motion being substantially along the circumference of the tubes and arising out of the continuous extroversion of the core 5 so as to form the external walls, the latter having, at any particular instant, substantially zero speed with respect to the conduit 6. The motion of the torus 4 in the conduit 6 therefore takes place with substantially reduced frictional resistance.

A displacement of the inner surface so as to be transformed into an outer surface is referred to in this specification and claims as "extroversion."

FIGS. 2a and 2b show the construction of the inlet valve 3 through which a fluid may be injected into the hollow interior of the torus 4. As can be seen, two apertures 3a and 3b are formed respectively in the two tubes 1 and 2, these apertures 3a and 3b being spaced from each other and being connected by a channel 3c, which channel 3c is left free when the two tubes 1 and 2 are bonded together. Fluid can then be injected into the torus 4 through the outer aperture 3a, the channel 3c and the lower aperture 3b. When the toroidal envelope has been filled with the fluid the pressure generated therein closes the channel 3c thereby ensuring that the fluid in the torus 4 is trapped therein.

It will be appreciated that as a result of the extroversion of the core 5, the latter will advance in a given direction whilst the external surface of the torus 4 has at all times substantially zero speed relative to the surrounding medium. In effect therefore the torus as a whole can be made to advance but by virtue of the fact that the advance takes place as a result of the extroversion of the moving core the advance is subject to substantially reduced (theoretically eliminated) frictional resistance by the surrounding medium. This particular property can be utilized when it is desired to place the torus in contact with a surrounding medium such as, for example, a surrounding viscous medium thereby reducing to a minimum the frictional resistance to movement.

Referring now to FIG. 3, the transporter is an elongated flexible torus 11 similar to the torus 4 of FIGS. 1a to 1e, the inner walls thereof defining a longitudinal passageway 12. The transporter is provided with inlet and outlet ducts and valves (not shown) through which flowable cargo may be introduced into and withdrawn from the interior of the transporter.

The transporter is provided with a harness 13 comprising a rigid frame 14 on which are mounted sets of radially directed pulleys 15. Harnessing loops 16 respectively pass over the pulleys 15 and through the longitudinal passage-way 12 of the torus 11 and around the transporter. The harness 13 is coupled via a towing cable 17 to a suitable towing means, for example, a tugboat (not shown).

The transporter and the harness 13 are so constructed and are formed of such materials that when the hollow interior of the transporter is filled with the flowable material which it is to transport the overall specific density of the assembly is near that of the water through which it is to be transported and in consequence the assembly is entirely or substantially submerged.

When the assembly as described above is subjected to towing, then as long as the speed of towing is below a certain minimum value, the whole assembly will be pulled along against the full viscous resistance of the water in which the assembly is submerged. When, however, the speed of towing exceeds this minimum value then the viscous resistance will become sufficiently great for extroversion of the toroidal transporter to take place and in consequence the rate of movement of the external surface of the transporter with respect to the surrounding water will be reduced.

It will be realized that the extroversion of the transporter takes place against the resistance to deformation of the flexible walls of the transporter and against the inner hydrodynamic resistance of the liquid in the transporter. When the resistance to deformation of the flexible walls of the transporter is exceeded by the external viscous resistance, then the hydrodynamic resistance of the fluid in the transporter can only limit the rate of extroversion of the transporter, but cannot prevent extroversion from taking place. This is in view of the face that this form of resistance is only created as a result of the extroversion and increases as the rate of extroversion increases.

As the speed of towing increases to a level at which extroversion takes place, an equilibrium will be set up between these inner resistances to extroversion and the outer viscous forces active on the external surface of the transporter which lead to extroversion. Under such conditions of equilibrium the speed of movement of the transporter as a whole can be considered as consisting of two essential components, namely:

a. the velocity of the transporter as a whole with respect to the outer walls thereof, and b) the velocity of the outer walls of the transporter with respect to the surrounding water. It will be readily realized that it is only the latter component which causes the extroversion of the transporter.

It will be furthermore realized that whilst these internal resistances tend to limit the extroversion of the body they cannot prevent it altogether and, as long as extroversion takes place at all, the resulting overall reduction in the viscous resistance to movement of the transporter leads to considerable economies in transportation costs.

FIGS. 4 and 5 show a modified form of bulk goods transporter which effectively consist of an inner rigid (i.e., non-extrovertible) cylindrical container 21 whose ends are sealed and which is formed with a coaxial bore 22, the container 21 therefore effectively constituting a hollow sealed torus. The rigid cylindrical container 21 is completely enveloped by a hollow flexible-walled torus 23 whose inner walls 24 extend through the bore 22. Radially directed sets of pulleys 25 are mounted on radial brackets 26 formed integrally with each end of the rigid container 21 so as to guide the movement of the external flexible torus 23. The space 27 between the external flexible torus 23 and the inner rigid container 21 is completely filled with fluid, e.g., water or air. Access to the inner rigid container 21 in which, for example, bulk goods are to be carried is via inlet ports (not shown) formed in the external flexible torus 23 and water-tight portholes (not shown) which permit access to the rigid container 21. The entire assembly shown in FIG. 4 may be provided with a harness of the kind shown in FIG. 3, the entire assembly being of specific density near that of water so that the assembly is entirely or substantially submerged. When the assembly is towed, the outer flexible torus 23 extroverts in a similar manner to the torus described with reference to FIGS. 1 to 3 of the drawings, i.e., an inner surface of this outer torus is transformed into an outer surface.

In view of the fact that the outer flexible torus extroverts when it is propelled at a minimum speed, economies in transport costs are obtained in a similar manner to those obtained with the construction shown in FIG. 3 of the drawings.

The flexible walled transporter can be made of any suitable flexible water-tight material of appropriate strength. Suitable material for this purpose can, for example, be coated fabrics, such as nylon or steel wire fabrics coated with an elastomer such as neoprene or latex. Thus the transporter shown in FIGS. 4 and 5 and the subsequent drawings still to be described are formed of a mesh of crossed nylon or steel wires which are impregnated with neoprene or latex.

FIG. 6 shows a transporter formed of such a flexible material in perspective view with parts broken away to show clearly how an external flexible torus 31 surrounds a rigid cylindrical container 32, the central portion 33 of the torus 31 passing through a central bore 34 of the container 32. The transporter is provided with a harness 35 consisting of a frame 36, pulleys 37 mounted thereon and loops 38 which respectively pass around the pulleys and over and through the torus, the harness being finally provided with a towing cable 39.

In the construction shown in FIG. 6 the space 40 between the torus 31 and the rigid container is intended to be filled with a liquid, such as, for example, water.

In the embodiments shown in FIGS. 7 to 10 of the drawings the space between the torus and rigid body is intended to be filled with air or other gases. Under these circumstances it is necessary to balance the external hydrostatic and hydrodynamic pressure by an appropriate internal pressure pattern, otherwise dry frictional resistance would be created between the outer torus and the inner rigid body or hull. For this purpose, as shown in the figures, a hollow cylindrical hull 43 is provided with a system of longitudinally extending integrally formed peripheral ribs 44 and circumferential end ribs 45. By means of these ribs and a closed pumping system (not shown) it is possible to maintain partially separated air pressure areas and thereby to compensate for the differing hydrostatic pressure effects.

In order to facilitate access to the hull interior a section thereof must remain exposed and in this can be formed a port hole. Such an exposed section 46 is shown in FIGS. 7 and 10. The flexible envelope which surrounds this exposed section, in order to maintain a tight seal is arranged to have its edges pass appropriate sliding joints 46a and then to come together again. In this way a suitable seal is always maintained. The sliding joint may be formed by a rib on the hull slidingly engaged by a turned under edge of the flexible envelope as shown in FIG. 10.

In general such sliding seals can be provided whenever any portion of the hull is to be exposed for any purpose such as, for example, when a propeller is to be attached thereto.

FIGS. 7 and 9 show clearly how the flexible envelope formed of a mesh as previously described is bunched together so as to enter the central bore of the rigid body hull.

FIGS. 11 to 13 show modifications of the present invention wherein the transporter is formed of a series of like unit containers 51. Each container 51 consists of a substantially cylindrical box through the lower portion of which extends a slot 52. The unit containers 51 are filled on a container hull 53 which comprises a pair of end noses 54 rigidly coupled together by a flat rib 55, the container 51 being accommodated between the noses 54, the rib 55 being inserted into the aligned slots 52. A central axial bore extends through each nose 54 and is aligned with the hollow inner portion of the rib 55. A flexible envelope passes through the aligned bores and hollow rib 55 and either completely surrounds the loaded containers 51 as in FIG. 12 or, as in FIG. 13, partially surrounds them, being coupled thereto by sliding guides, the portions between the flexible envelopes and the containers being filled by a suitable fluid and the transporter either being towed or being provided with self-propelling means.

In all cases the transporters in accordance with the present invention can either be towed or can be provided with self-propelling means. In the latter case steering of the transporter can, for example, be effected by inducing controlled assymetrical wave motion in the flexible container by varying the pressure in the filling fluid.

Claims

I claim:

1. A submersible transport apparatus comprising a flexible hollow generally toroidal envelope having inner and outer surfaces, said inner surface being extrovertible toward said outer surface at the leading end of the apparatus and said outer surface being simultaneously introvertible toward said inner surface at the trailing end of the apparatus, and transport means for displacing said envelope axially through a fluid medium, said transport means including a plurality of guide elements with endless surfaces engageable and movable with the walls of said envelope at angularly spaced locations about the axis of the envelope for guiding said walls in the direction of travel of the envelope in said fluid medium and for imparting to the envelope a traction, which together with the frictional forces acting on the envelope as a result of movement through the fluid medium causes said envelope to develope a combined sliding and rolling motion with respect to the external fluid medium, and a substantially cylindrical, hollow and rigid container formed with an axial passage, said envelope surrounding said container and passing through said passage.

2. The apparatus defined in claim 1, wherein said transport means includes means for driving at least one of said elements for eversion of said surfaces.

3. The apparatus according to claim 1, wherein said envelope is formed of a mesh of longitudinal and transverse fibres impregnated with an elastic fluid-tight substance.