DESCRIPTION OF THE PRIOR ART A worm is known since Archimedes. When rotated, a worm can either transport a medium, or travel within the medium. Accordingly, worms are used in transportation, i. e. in vehicles and pipeline transportation systems.

For the most part the vehicles having a cross-country capacity are track-laying vehicles. Track-laying vehicles show relatively good flotation on loose grounds.

However, the use of such vehicles is limited. On a road with a hard surface, tracks will damage the road surface, and on unstable grounds such as quaking bog or deep snow, tracks can slip. One alternative to tracks as a carrying and propelling device for a vehicle is a pair of laterally spaced parallel worms or helical members threaded in opposite directions (see, e. g. GB 2,300, 842). Such members, when rotated, engage with the ground and propel the vehicle mounted thereon in the direction of their axes. These vehicles can outperform track-laying vehicles on unstable grounds. Further, they can even effect a propelling function in water, thus providing a base for creating amphibian vehicles as disclosed in US 3,333, 563. However, on a road with a hard surface, helical members will not effectively propel the vehicle in the direction of their axes. Obviously, a vehicle carried by helical members will still be damaging the road surface. Further, it is essential for a vehicle of this type that both helical members are active. In case one of the members fail, the vehicle cannot move straight and can only circle, therefore, survivability of the vehicle is low.

Further, worms or helical members are widely used for pipeline transportation of media having various levels of flowability. In some applications, e. g. when a

curing medium is transported in a stop-and go manner, mixing of a medium is needed when the transportation is stopped. For example, a helical transporter mounted in a pipe can be used for feeding concrete from a concrete mixer to the truck. When the truck is full, the feeding of concrete is stopped until another truck appears. However, if a delay between the trucks is long, the concrete can cure in the pipe. Thus, mixing of concrete in the feeding device is desirable when the feeding of concrete is stopped.

SUMMARY OF THE INVENTION Thus, one object of the invention is to provide a transportation member for a vehicle, which member carries and propels the vehicle and ensures that the vehicle can travel effectively both on roads with hard surface and on loose or unstable grounds.

Another object of the invention is to provide a vehicle having an increased survivability, i. e. a vehicle that keeps its mobility even when one of its carrying and propelling members fails.

Still another object of the invention is to provide a transportation member for pipeline transportation of a fluid such as thick liquid, granular material, etc. , which member can perform a mixing operation when the transportation is stopped.

In one aspect of the invention, an adjustable transportation member is provided, the member comprising a barrel in which a plurality of blade mounts are arranged helically with respect to the barrel surface, wherein each blade mount is provided with a blade, is attached to the barrel in a movable manner and is disposed transversely to the barrel surface, and the blades are adapted to form a helical rib on the barrel surface. When this helical rib is engaged, at least partially, with a ground or viscous medium and the barrel is rotated, a force component is created in the direction of the barrel axis.

In one embodiment each blade mount is a spindle journalled in bearings on the barrel, and the adjustable transportation member is provided with a mechanism for controlling the angular position of the blades carried by the spindles.

Therefore, the blades can be turned around the spindle axis. In particular, the

blades can be turned to the position in which they are parallel to the barrel axis and therefore do not create a force in the direction of this axis when the barrel is rotated. Instead, the blades create force in a circular direction.

In another embodiment each blade mount is a plunger adapted to controllably extend the blade out of the barrel and retract the blade inside the barrel through an opening in the barrel surface. Obviously, when the blades are retracted, they do not create any force in any direction.

Preferably, the barrel is tapered at both its ends, and a starting helical rib is formed on the tapering ends of the barrel, wherein the starting helical rib matches with the helical rib formed by the blades.

The blades can form a multistart helical rib on the barrel surface.

In another aspect of the invention, a vehicle is provided, the vehicle comprising a motor, a frame, a pair of laterally spaced adjustable transportation members as described above, journalled in bearings on the frame, and a power transmission from the motor to the transportation members. Preferably, the helical ribs on the transportation members are of opposite hands. However, in some applications the helical ribs can be of the same hand. When the helical ribs formed by the blades of the adjustable transportation members are engaged with the ground (or water in case of an amphibian vehicle), and the barrels are rotated, a propelling force is created, and the vehicle moves in the direction of the barrels axes.

Preferably, the power transmission is adapted to selectively reverse rotation of at least one transportation member and change relative speeds of rotation of the transportation members for reversing and steering the vehicle.

In one embodiment, each blade mount is a spindle journalled in bearings on the barrel, and the adjustable transportation member is provided with a mechanism for controlling the angular position of the blades carried by the spindles. Therefore, the blades can be turned around the spindle axis. In particular, the blades can be turned to the position in which they do not form a helical rib (e. g. are parallel to the barrel axes) and therefore do not propel the vehicle in the direction of the barrel axes when the barrels are rotated. Instead,

the transportation members function as rollers in which the peripheral ends of the blades act as tread, and a vehicle can roll on the transportation members in a transverse direction to the barrel axes. When travelling on the road, rolling is less damaging for the road surface than the above-described axial transportation by means of the helical rib.

In another embodiment, each blade mount is a plunger adapted to controllably extend the blade out of the barrel and retract the blade inside the barrel through an opening in the barrel surface. Obviously, when the blades are retracted, they do not create any force in any direction. and therefore do not propel the vehicle in the direction of the barrel axes when the barrels are rotated. Instead, the transportation members function as rollers in which the outer periphery of the barrels act as tread, and a vehicle can roll on the transportation members in a transverse direction to the barrel axes. When travelling on the road, the whole barrel surface engages the road, therefore this kind of transportation is even less damaging for the road surface than rolling on the peripheral ends of the blades, as in the previous embodiment.

In an amphibian vehicle, the barrel can comprise at least one sealed chamber filled with gas or a chamber filled with a buoyant material.

Preferably, the barrel is tapered at both its ends, and a starting helical rib is formed on the tapering ends of the barrel, wherein the starting helical rib matches with the helical rib formed by the blades.

At least one extendable support ending in a wheel or slide can be attached to the frame and adapted to bear the vehicle when one transportation member fails. This will increase survivability of the vehicle.

A resilient cover can be attached to the outer peripheries of the blades. This will make the transportation members even less damading.

In another aspect of the invention, a pipeline transportation device is provided comprising a pipe and an adjustable transportation member as described above disposed within the pipe and journalled in bearings on the pipe. Such a device can be usef for for transporting and mixing a fluid medium such as thick liquid, granular material, etc.

In the device, each blade mount can be a spindle journalled in bearings on the barrel. In this case, the adjustable transportation member is provided with a mechanism for controlling the angular position of the blades carried by the spindles. Thus, when the blades form a helical rib on the barrel surface, the medium is transported through the pipe. When the blades are turned to the position in which they do not form a helical rib (e. g. are parallel to the barrel axes), the medium is mixed, but not transported.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view of an adjustable transportation member, wherein the blades form a helical rib on the barrel surface.

Fig. 2 is a side view of the adjustable transportation member according to one embodiment of the invention, wherein the blades are turned in parallel to the barrel axis.

Fig. 3 is a partial cross-section of the adjustable transportation member according to one embodiment of the invention, along the line A-A in Fig. 1, wherein by convention the barrel surface is shown as flat to simplify the drawing.

Fig. 4 is a partial cross-section of the adjustable transportation member according to another embodiment of the invention along the line A-A in Fig. 1, wherein by convention the barrel surface is shown as flat to simplify the drawing, and the blades are in their extended position.

Fig. 5 is a partial cross-section of the adjustable transportation member of Fig. 4 wherein the blades are in their retracted position.

Fig. 6 is a partial cross-section of the adjustable transportation member of Fig. 4 along the line B-B in Fig. 1, wherein the blades are in their extended position.

Fig. 7 is a partial cross-section of the adjustable transportation member of Fig. 6, wherein the blades are in their retracted position.

Fig. 8 is a side view of an adjustable transportation member wherein the barrel is tapered at both its ends.

Fig. 9 is a schematic plan view of a vehicle according to the invention.

Fig. 10 is a schematic plan view of a vehicle according to one embodiment of the invention, wherein the frame comprises two parts connected by a detachable hinge.

Figs. 11-13 shows cross-sections of resilient covers of different shapes.

Fig. 14 shows a schematic side view showing a vehicle of Fig. 10 with extendable supports.

Fig. 15 shows a sectional view of a pipeline transportation device according to the invention.

According to one embodiment shown in Figs. 1-3, an adjustable transportation member 1 comprises a barrel 2 having a plurality of equally spaced openings 3 (best seen in Fig. 3, in which by convention the barrel surface is shown as flat to simplify the drawing) arranged helically in the cylindrical wall thereof. In the openings 3, blade mounts in the form of spindles 4 are journalled in bearings 5, each spindle 4 having a blade 6 attached to its external end. Obviously, the blade can be integrally formed with the spindle. A rack-and-pinion mechanism is provided for controlling the angular position of the blades. The mechanism is driven by a hydraulic cylinder 7 attached to the inner periphery of the barrel in the vicinity of each opening 3, the plunger of the cylinder comprising a rack 8 disposed transversely to the spindle 4. Engaged with the rack 8, is a pinion 9 fit on the internal end of the spindle 4. Hydraulic cylinders used in the invention are in fluid communication with a traditional hydraulic system not shown in the drawings because it does not constitute the essence of the invention.

To allow free rotation of the blades 6, the length of each blade 6 shall not exceed the space between the openings 3. In Fig. 1, blades 6 are shown in a position in which they form a helical rib on the barrel surface. When this helical rib is engaged, at least partially, with the ground or a viscous medium and the barrel is rotated, a force component is created in the direction of the barrel axis.

To rotate the blades to the position in which the blades are parallel to the barrel axis, hydraulic cylinder 7 is actuated, and the rack 8 rotates the pinion 9 together with spindle 4 and blade 6. The rack-and-pinion mechanism is configured in such a way that the full travel of the pinion rotates the blade from the position shown in Fig. 1 to the position in which the bades are parallel to the barrel axis as shown in Fig. 2. In this position, the blades do not create a force in the direction of the barrel axis when the barrel is rotated. Instead, the blades create a force in a circular direction.

According to another embodiment shown in Figs. 4-7, in which by convention the barrel surface is shown as flat to simplify the drawing, an adjustable transportation member 10 comprises a barrel 11 having a plurality of equally spaced slots 12 arranged helically in the cylindrical wall of the barrel. A hydraulic cylinder 13 is attached to the inner periphery of the barrel at the center of each slot 12 by means of a holder 14. A plunger 15 of the cylinder 13 has a blade 16 attached to the external end threof. Obviously, the blade can be integrally formed with the plunger. Further, a group of adjacent blades can be attached to one plunger. On actuation of the cylinder, the plunger travels berween its extended and retracted positions.

When plungers 15 are extended (see Figs. 4 and 6), blades 16 form a helical rib on the barrel surface. In this state, the adjustable transportation member 10 looks the same as the adjustable transportation member 1 in Fig. 1. Therefore, Fig. 1 relates to both embodiments disclosed herein. When the barrel is rotated, an axial force component is created in the same way as described above. When the plunger is retracted (see Figs. 5 and 7), the blades 16 hide inside the barrel through the slots 12, so that no substantial force is created by rotation of the barrel. In an alternative embodiment, a continuous helical slot instead of slots 12 can be formed in the cylindrical wall of the barrel for the passage of blades 16. This slit can include resilient partitions separating and sealing the blades from each other.

In an embodiment shown in Fig. 8, the barrel is tapered at both its ends, and a starting helical rib 25 is formed on the tapering ends of the barrel. As seen in Fig. 8, rib 25 matches with the helical rib formed by the blades.

It is clear for those skilled in the art that other mechanisms for rotating and/or retracting the blades can be used. Further, the two above embodiments can easily be combined to achieve an adjustable transportation member in which the blades can be both rotated and retracted.

According to the invention, the above-described adjustable transportation member 1 or 10 can be used in a vehicle. As shown in Fig. 9, a pair of laterally spaced adjustable transportation members 1 or 10 is journalled in bearings 22 on a frame 23. Not shown in the drawings, are a motor, a power transmission from the motor to the transportation members, a driving cab and a device for holding an effective load. These can be designed in a variety of traditional ways not described herein. It is preferred, however, that the power transmission is adapted for selectively reversing rotation of at least one transportation member and selectively changing relative speeds of rotation of the transportation members for reversing and steering the vehicle.

When the helical ribs formed by the blades of the adjustable transportation members are engaged with the ground (or water in case of an amphibian vehicle), and the barrels are rotated, a force is created having both an axial force component and other force components. As seen in Fig. 9, the helical ribs on the transportation members are of opposite hands. Thus, on rotation of the barrels in opposite directions axial force components add up, and other force components cancel, and the vehicle moves in the direction of the barrels axes.

However, in some applications the helical ribs can be of the same hand. Up to this point, the vehicle operates in the same way as those known from the prior art.

Further, when adjustable transportation member 1 is used in the vehicle, the blades 6 can be rotated to the position in which they are parallel to the barrel axis and therefore do not propel the vehicle in the direction of the barrel axes when the barrels are rotated. Instead, the transportation members function as

rollers in which the peripheral ends of the blades act as tread, and a vehicle can roll on the transportation members in a transverse direction to the barrel axes.

When travelling on the road, rolling is less damaging for the road surface than the above-described axial transportation by means of the helical rib.

When adjustable transportation member 20 is used in the vehicle, the blades can be retracted inside the barrel through the slots 12. Obviously, when the blades are retracted, they do not create any force in any direction and therefore do not propel the vehicle in the direction of the barrel axes when the barrels are rotated. Instead, the transportation members 10 function as rollers in which the outer periphery of the barrels act as tread, and a vehicle can roll on the transportation members in a transverse direction to the barrel axes. When travelling on the road, the whole barrel surface engages the road, therefore this kind of transportation is even less damaging for the road surface than rolling on the peripheral ends of the blades, as in the previous embodiment.

To impart the vehicle amphibian properties, the barrel comprises a chamber (not shown in the drawings) filled with gas or buoyant material such as foam plastic. The chamber is sealed when filled with gas. Further, a compressed air can be continuously fed into the barrel to maintain a high pressure in the barrel, thereby preventing outside water from getting in. The frame can also comprise a chamber filled with a buoyant material.

An embodiment of the vehicle is shown in Figs. 10 and 14. According to this embodiment, the frame comprises two parts 24 and 25 connected by a detachable hinge 26. Each part 24 and 25 holds one adjustable transportation member. In the event that one of the adjustable transportation members is damaged for some reason, the hinge can be detached to get rid of the damaged part, and the undamaged member will still assure mobility the remaining part.

To facilitate moving one detached part of the frame, an extendable support can be used. Shown in Fig. 14, is one detached part of the frame carrying one adjustable transportation member. An extendable support 26 with a wheel 27 is attached to the frame. Intstesd of wheel, a slide (not shown) can be used. In the drawing, an extended position of extendable support 26 is shown in full lines,

and a retracted position thereof is shown in dotted lines. Extendable support 26 is adapted to bear the vehicle when one transportation member fails. This will increase survivability of the vehicle.

A resilient cover can be attached to the outer peripheries of the blades. This will make the transportation members even less damading. In Figs. 11-13, various forms of resilient coves are presented. Naturally, other forms of covers can be used.

In another aspect of the invention illustrated by Fig. 15, the above-described adjustable transportation member 1 can be used in a pipeline transportation device comprising a pipe 30 and an adjustable transportation member 1 disposed within the pipe and journalled in bearings 31 on holders 32 attached to the pipe. Such a device can be used for for transporting and mixing a fluid medium such as thick liquid, granular material, etc.

When the blades form a helical rib on the barrel surface as shown in Fig. 1, the medium is transported through the pipe. When the blades are turned to the position as shown in Fig. 2 in which they are parallel to the barrel axes, the medium is mixed, but not transported.

One possible application of the above pipeline transportation device is for transportation of a curing medium in a stop-and go manner. When the transportation is stopped, mixing of a medium is needed. For example, the device can be used for feeding concrete from a concrete mixer to the truck.

When the truck is full, the feeding of concrete is stopped until another truck appears. However, if a delay between the trucks is long, the concrete can cure in the pipe. This problem is solved by using a pipeline transportation device of the invention.