Guided vehicle

Abstract

A vehicle according to this invention comprises a chassis (1), four articulated extensions (2, 3, 4, 5) carrying wheels and connected to the chassis, and control means for regulating movements of each movable part of the extensions. One pair of the extensions (3, 4) comprises pivotal or linear movement essentially moving the extension carrying wheels outwards. The other pair of extensions (2, 5) forms together with the chassis a central gravity generated normal force linkage mechanism utilized in vertical movement. Each articulated extension comprises one movement with respect to the chassis adequately described as pitch.The vehicles go on their own propulsion from one place to another moving on a variety of different mateable guideway sections including flat base surface like shop floor, bifurcations, vertical rails and various other intersections and can convey vehicles in horizontal, inclined or vertical direction. This capability represents a truly unique door-to-door driverless freight delivery transportation system

Description

[0001] A VEHICLE

[0002] FIELD OF THE INVENTION

[0003] Transportation

[0004] TECHNICAL PROBLEM

[0005] Technical problem is the absence of a vehicle representing the most important component of a novel freight delivery or personal transportation system that can be operated as a fully automated driverless land transportation system especially suited for densely populated urban and suburban areas, campuses, plants, and spacious business or residential buildings.

[0006] STATE OF THE ART

[0007] The state of the art includes guideway or railway based internal parcel transportation systems which deliver small or medium sized packages to an apartment or a single room within a building. These systems are restrained to single building or a few buildings and shorter distances as their design of the wheel to rail engagement causes the level of friction not appropriate for longer distance travel. Some of the internal parcel transportation systems are based on active switches which connect different routes of the guideway or railway system. Active switches increase complexity and cost of the guideway or railway construction and maintenance.

[0008] The state of the art includes guideway-based transportation systems which are used to transport people or goods. One example is a Personal Rapid Transit System (" PRT") class of transportation systems. These systems generally comprise a transit vehicle that is controlled to self-steer along a guideway track or roadway having surfaces designed to restrain the vehicle to the track. The vehicle generally includes a plurality of guide and support wheels designed to couple the vehicle to the guideway. These systems are designed to replace or augment car, bus and train based transportation where appropriate based on efficiency or other considerations. With the growing population the cities grow in height by building ever higher skyscrapers thus increasing the demand for a kind of PRT which could replace or augment elevator based transportation in addition to car, bus and train and which could easily connect buildings many floors above the ground or convey vehicles along steeply inclined routes.

[0009] The US4015537 discloses an interior railway transportation system where a self-propelled car and load-conveying container on the car travel along a track system which has horizontal and vertical track runs with bends or curves between such runs, and inside and outside corner bends or curves between horizontal track runs. The track is generally channel-shaped with spaced rail heads at the extremities of the channel legs. The channel web always has vertical orientation for the horizontal and vertical track runs and bends. Motor-driven friction rollers move the car along the track. Spring-pressed, rounded-groove guide wheels support the car on the track but also causes wear, increased energy consumption, noise, vibration and limit the maximum speed. The track system has switches to connect the system between various stations at various locations on the same or different building floors but this also increases complexity and cost of the railway construction and maintenance.

[0010] The Slovenian patent 24503 discloses a transportation system comprising of a self-propelled robotic vehicle and a matable guideway. The robotic vehicle features eight arms having each at least two degrees of freedom: pitch and yaw. The matable guideway is basically a passive track system which has horizontal and vertical track runs and a horizontal to vertical crossing regions with no active parts. The robotic vehicle travels along the track system and when entering into bifurcations of the horizontal track runs or into a horizontal to vertical crossing regions, the vehicle changes direction autonomously by engaging or disengaging one side of its arms with the requisite side of the guideway respectively. The vehicles can travel with the efficiency of a car along horizontal or mildly inclined ground guideway sections, can ascend or descend with the efficiency of an elevator up and down in vertical or steeply inclined guideway sections and can travel on a shop floor like contemporary robotic and automated vehicles for delivering or transporting material indoors. The construction of the vehicle is quite demanding in terms of cost and weight as it requires power 16 actuators at least to facilitate the pitch and yaw movement of each robotic arm separately and 8 motors at least to propel the driving wheels of each arm. Additionally, the power actuators dedicated to perform the pitch movement must also exert enough force to sufficiently press the wheels against the rail in order to generate enough friction necessary for the traction based vertical movement.

[0011] The US6431078 among others discloses a vehicle that may move in different directions: horizontal, steeply sloped and also vertical tracks, based on traction wheel assemblies that roll on wheel tracks. The cabin of this vehicle is mounted on a cantilever, thereby displacing its center of gravity with respect to the wheel guides. Thus, a lever action is established, which presses the wheels against the wheel tracks producing enough normal force and therefore enough frictional resistance is obtained to enable working of the traction wheels on the tracks. However, the cantilever mechanism that employs frictional resistance requires extra space increasing the necessary cross section of the ducts and shafts which conduit the vehicle.

[0012] DESCRIPTION OF NEW INVENTION

[0013] A vehicle solves above referenced technical problems compared with US6431078, and compared with the Slovenian patent 24503 wherein the novel vehicle employs a central gravity generated normal force linkage mechanism. This mechanism is not based on cantilever and thus does not require extra space and consequently does not increase the necessary width and height of ducts and other spaces dedicated to this type of transport as is the case with US6431078. In US6431078 the size of the normal force depends on the length of just one lever which necessarily positions the driving wheels eccentrically with respect to the center of gravity of the vehicle. Thus its motor power is concentrated on the respective one side of the vehicle. Said central gravity generated normal force linkage mechanism of the present invention positions the center of gravity of the vehicle in the middle between the front and the rear extensions which carry also the horizontal driving wheels. In that way said mechanism is able to exploit the motor power sources from the front and rear sides of the vehicle. This novel mechanism too needs an actuator for lifting the weight of respective arms and holding them aligned with the vertical rail as is the case with the Slovenian patent 24503, however it doesn’t need the additional much larger force necessarily exerted by the actuator of the Slovenian patent 24503 to generate the normal force which produces enough friction for the vertical drive as could be inferred from the descriptions in the Slovenian patent 24503. In this novel design presented here this extra force is generated by said central gravity generated normal force linkage mechanism without any energy input but gross weight of the vehicle inclusive cargo alone.

[0014] In addition, the advantage over the previous specifications, in particular over the Slovenian patent 24503, by a simplified and cheaper construction of the robotic vehicle which in the embodiments presented hereafter features four arms, two of them without the yaw degree of freedom, instead of eight arms each having multiple degrees of freedom including yaw, 4 motors to propel the driving wheels instead of 8, and not more than 6 power actuators instead of 12 to facilitate steering and changing direction of the vehicle, not compromising on the advantages of the said patent over the previous art. In particular this relates to two features. First is the ability of the vehicles to travel with the efficiency of a car along horizontal or mildly inclined ground or suspended guideway sections and to ascend or descend with the efficiency of an elevator up and down in vertical or steeply inclined direction along vertical or steeply inclined guideway sections and to travel on a shop floor like contemporary robotic and automated guided vehicles for delivering or transporting material indoors. Second is the passive nature of the track system requiring little maintenance. In addition, this invention features battery powered vehicles which means that the track system doesn't need power lines.

[0015] For purposes of these specifications word “mateable” refers to at least two interdependent systems which can be connected, put together, mated together or otherwise put into one on another dependent status. This invention seeks to disclose a new vehicle comprising one or more of the following characteristics:

[0016] A vehicle features a chassis and four articulated extensions. Said extensions are attached to said vehicle in such a fashion that they form two side pairs, the left side pair and the right side pair, with each side pair having one front and one rear extension, all relative to the general direction of said vehicle's main horizontal movement.

[0017] Each said extension comprising one or more main horizontal driving wheel sets wherein each set comprises only wheels rotating about the same axis and at least one said main horizontal driving wheel set is with its respective bearings fixedly attached to each extension. Said extensions share basically the same set up and geometry with respect to the composition and position of the horizontal driving and guiding wheels necessary to exploit without restrictions the geometry of various horizontal guideway sections and intersections.

[0018] The two extensions of one said side pair are simultaneously movable horizontally in transverse direction, stretching out and carrying the horizontal guiding wheels into the engaged position by rotating about a hinge pin or moving straight along transverse guides when the vehicle is changing its direction of movement from vertical to horizontal and vice versa. The two extensions of the other said side pair are fixedly attached to the chassis each comprising at least one vertical driving wheel set wherein each set comprises only wheels rotating about the same axis.

[0019] Said four extensions feature a second member pivotally movable about the pitch axis carrying the upper horizontal guiding wheel into the engaged position with the horizontal rails when necessary.

[0020] Said second members pivotally movable about the pitch axis of the fixed extensions are also, by the same rotation, carrying respective vertical driving wheel sets into the engaged position with the vertical rails when necessary thus forming a linkage mechanism featuring a gravity generated normal force needed to produce the requisite traction of the wheels against the rails. Said vehicle features main traction wheel and Mecanum wheel on the same shaft. The guideway construction facilitates the use of the main traction wheel in the straight and mildly curved sections of the guideway and facilitates the use of the Mecanum wheel on a flat surface or in the bends and sharply curved sections of the guideway resulting in a favorable trade-off between smooth voyage, low noise, ability to perform sharp turns in confined spaces and total cost of ownership.

[0021] Said vehicle provides for movement along a guideway system using guideway switches and intersections that have no moving parts.

[0022] In particular, a vehicle according to this invention is comprising a chassis and four extensions, wherein, with respect to the direction of the horizontal moving of the vehicle, two of said extensions are positioned in front of the transverse vertical plane running through the center of gravity of the empty vehicle and two of said extensions are positioned behind said transverse plane thus dividing the extensions into the front extensions and the rear extensions respectively, one said front extension and one said rear extension being positioned to the left of an lateral vertical plane running through the center of gravity of the empty vehicle and one said front extension and one said rear extension being positioned to the right of said lateral plane thus dividing the extensions by their side into the left and the right side pair respectively. It should be specifically noted that the description of the two vertical planes is not meant as a limitation but simply to describe in words the relevant geometrical relationships of the vehicle.

[0023] Further, said vehicle according to this invention is comprising control means for controlling movements of each said movable member

[0024] Further, when the vehicle is moving horizontally and straight, said extensions are positioned in front of or at the back of said chassis and when recessed are not stretching out of the hypothetical envelope determined by the transverse cross-section of the chassis and the direction of moving save for the minimal projections of the driving and guiding wheels.

[0025] Further, the vehicle according to this invention is comprising eight or more horizontal guiding wheels wherein at least two of said main horizontal guiding wheels are attached to each extension.

[0026] Further, the vehicle according to this invention wherein said main horizontal driving wheel set comprises: a traction wheel; and a Mecanum wheel, both wheels attached fixedly to the same driving shaft and the Mecanum wheel having a bigger diameter then the traction wheel.

[0027] Further, the vehicle according to this invention wherein each said extension featuring a vertical driving wheel has at least one additional member connected movably to each first member of the fixed extensions by a revolute joint or by linear guides and engaged with the respective second member and said vertical guiding wheel attached to said additional member.

[0028] Further, the vehicle according to this invention defines a central gravity generated normal force linkage mechanism comprised of the chassis compound body, tilted arms and vertical driving wheel sets wherein the chassis compound body is formed by the chassis and the first members of the fixed extensions and the tilted arms are coincident with the second members of the fixed extensions respectively. On the lateral plane projection, the compound chassis is positioned in the middle between the two tilted arms protruding upwards from the chassis on the left and the right side respectively and attached pivotally to the chassis by their pitch revolute joints. Said vertical driving wheel sets are attached to the tilted arms at their distal side. Each said driving wheel set comprises one wheel array attached to the respective tilted arm or more wheel arrays having parallel axes and mounted to a trolley which is pivotally attached to the respective tilted arm.. Said linkage mechanism has two joints coincident with the pitch revolute joints and two joints coincident with the axes of the vertical driving wheel arrays or coincident with the pivot of a trolley arm carrying said vertical driving wheel arrays. The linkage mechanism is designed so that the angle assumed with the horizontal line by the tilted arms is small enough for the linkage mechanism to exert enough normal force onto the contact surface of the vertical rails to hold the vehicle against the rails by the force of gravity alone when said vertical driving wheel sets are engaged with the vertical rails, powered and rotating or being halted.

[0029] Further, the vehicle according to this invention having said vertical driving wheel arrays which comprise one or more traction wheels per axis utilizing friction type of vertical movement or one or more of each, pinion and guiding wheels per axis to perform rack and pinion type of vertical movement.

[0030] The vehicles go on their own propulsion from one place to another moving on a variety of different mateable guideway sections. The mateable guideway sections can have various rail arrangements and can convey vehicles in horizontal, inclined or vertical direction. In addition, flat base surface like shop floor or a road can also be utilized as a valid guideway section, provided that requisite positioning control and safety systems are put in place. This capability represents true door-to-door driverless freight delivery or personal transportation that no other transportation system in use today can claim.

[0031] For purposes of this application a vehicle is also referred to as “robotic” vehicle.

[0032] Preferably it is robotic, i.e. autonomously moving and without particular human intervention, however, it can also act as normal vehicle with full human control (i.e. non “robotic” vehicle).

[0033] A vehicle according to this invention comprises a chassis, four extensions and control means for regulating movements of extension members accordingly. Said chassis may form a cuboid, or any other body form (e.g. sphere, or cylinder etc.). For purposes of this application the vehicle has three orthogonal axes defined relative to the chassis and corresponding to the translational and rotational degrees of freedom of the vehicle perceived as a solid body with position determined by the vehicle's movement. When the vehicle is moving nominally which means, for the purpose of this application, to move straight in a horizontal plane for which the direction of gravity is a normal, the first axis follows the path of the movement (also called the principle axis), the second axis is parallel to the direction of gravity, and the third axis, orthogonal to the first and the second, points sideways. The corresponding translational degrees of freedom of the vehicle coincide with the respective axes, the corresponding rotational degrees of freedom are: roll as the rotation about the first axis, yaw as the rotation about the second axis and pitch as the rotation about the third axis. When the vehicle is moving nominally i.e. straight in a horizontal plane, these axes and the corresponding rotational degrees of freedom are consistent with descriptions used for the rotational degrees of freedom of a ship or an aircraft - roll, yaw and pitch. However, when the vehicle is moving vertically, the chassis, unlike the fuselage of a plane, doesn't rotate about the pitch axis to follow the vertical direction of movement, nor does the chassis rotate about the roll axis. For the purposes of this application, to avoid ambiguity, the axes are defined as being fixed to the chassis as opposed to being aligned with the principal movement of the vehicle. It should be specifically noted that the description of the three axes is not meant as a limitation but simply to describe in words translational and rotational degrees of freedom of the vehicle.

[0034] In the preferred embodiment the extensions are designed and implemented asymmetrically in two basic forms of the extensions - the movable articulated arm form and the fixed articulated arm form. Each basic form consists of two mirror embodiments comprising the corresponding said side pair. This in total yields four different variants of arm forms. The movable articulated arm form is capable of moving the upper and the lower guiding wheels outwards with respect to the body of the vehicle by rotating about the yaw axis positioned at its proximal end and pushing its other end or by a transverse movement along linear guides moving the whole arm thus being able to shift the position of the vehicle on horizontal to vertical intersections. The fixed articulated arm form is equipped with the vertical driving wheel set which engages with vertical rails and in sync with its mirror counterpart belonging to the same said side pair propels the vehicle along the vertical rails. This arrangement makes the vehicle less expensive and lighter compared to the hypothetical fully symmetrical embodiment which would feature all four articulated extensions combining the pivotal attachment to the chassis and comprising the vertical driving wheel enabling the vehicle to engage with vertical rails or shifting its position on horizontal to vertical intersections with each side when the vehicle of the preferred embodiment is capable of performing a full 180 degrees turn on spot thus being capable of engaging with the vertical rails with the one side that is equipped with vertical driving wheels.

[0035] Each extension comprises also a main horizontal driving wheel set and upper and lower horizontal guiding wheels. The main horizontal driving wheel set is attached to the first member of the extension. The lower horizontal guiding wheels and the lower vertical guiding wheels are attached to the first member and the upper horizontal guiding wheels are attached to the second member. The pitch revolute joints connecting the first and the second member of each extension are rotated by four respective actuators. Each said fixed extension comprises also two vertical guiding wheels and a third member connected movably to the first member by a revolute joint. The vertical driving wheel set is attached to the second member of the fixed extension, and one said vertical guiding wheel is attached to the third member of the extension. The main horizontal driving wheel set comprises a traction wheel and a Mecanum wheel, both wheels attached fixedly to the same driving shaft. The Mecanum wheel has slightly bigger circumference than the traction wheel. When the vehicle is positioned over a flat surface the traction wheel doesn't reach the floor. Instead, the Mecanum wheel engages with the flat surface and propels the vehicle in any chosen direction determined by the differential rotation of each Mecanum wheel unobstructed or determined by the overhanging rails which are followed by the respective upper horizontal guiding wheels. The traction wheels only engage with the guideway when the guideway features raised surface beneath the traction wheels and has a recess under the rest of the vehicle which lets the Mecanum wheels disengaged. In this manner the traction wheels engage with the raised surfaces of the guideway section and propel the vehicle along the straight or mildly curved horizontal or mildly inclined sections of the guideway smoothly and with high speeds on longer stretches of the guideway.

[0036] In the preferred embodiment the vehicle uses the force of friction to be able to climb up or down a vertical or steeply inclined guideway section. This is performed by the vehicle having wheels' rims made of an appropriate material (such as, for example, rubber), the wheels being in contact with a track made of an appropriate material (such as, for example, steel) and by utilizing the working of the central gravity generated normal force linkage mechanism. When the vehicle is set to change direction from horizontal to vertical, the vertical driving wheel being attached to the second member engages with the vertical surface of the vertical rail by rotating about the pitch revolute joint.

[0037] The said vehicle can negotiate different forms of the guideway which may include but are not limited to the following sections:

[0038] a vertical section comprising of two vertical rails mounted in parallel defining a vertical plane. Matable with the preferred embodiment the profile of the rails is basically an open square resembling the capital letter G. Matable with the second embodiment, the profile of the rails is the same with the addition of the rack mounted on the upper side of the square G. The rails of the vertical section are laid so that their respective profiles are a mirror copy of each other. The opening of the square G is facing inwards into the space that conveys vehicle traffic;

[0039] a flat base surface where said vehicle can move with lower speeds freely, limited only by the man made rules and signs;

[0040] a horizontal section comprising of two equidistant rails, laid on or defining a horizontal or mildly inclined flat or mildly curved surface to facilitate high speed horizontal travel of said vehicle. In straight sections each rail comprises one essentially horizontal raised surface. When the horizontal curvature of the rails is significant each rail comprises two perpendicular surfaces one essentially horizontal raised surface and one inward looking lateral, essentially vertical, surface which engages with the corresponding lower guiding wheels;

[0041] a wall section comprising of two equidistant essentially horizontal rails laid one above the other thus defining a vertical plane or a mildly curved vertical surface, the lower rail preferably comprising two perpendicular surfaces, one essentially horizontal surface and one vertical inward looking lateral surface, the upper rail preferably comprising two vertical lateral surfaces facing each other to facilitate horizontal travel of said vehicle above ground or along the surface of a wall; a bifurcation which can be also described as a junction of three incoming routes. The angles of the incoming routes can vary. The bifurcation can also be described as branching off the main route. A bifurcation comprises essentially: a flat base surface and three overhanging rails, each defining the path of one side of the vehicle's upper horizontal guiding wheels entering the junction at one end and coming out at the respective other end. Each overhanging rail comprises the upper inner and outer rail, the upper outer rail defining inward lateral running surface mateable with the outward projecting part of the respective upper guiding wheels, the upper inner rail defining outward lateral running surface mateable with the inward projecting part of the respective upper guiding wheels;

[0042] a horizontal intersection which can be also described as a junction of two bidirectional routes at preferably right angle. A horizontal intersection comprises essentially: a flat base surface and four guiding rail sections each defining the path of one side of vehicle's horizontal guiding wheels approaching the intersection following one route, entering the junction at one end and coming out at the respective other end following the other route in the respective left or right direction. Each of the four guiding rail sections comprises an upper rail preferably comprising two vertical lateral surfaces facing each other and optionally the lower rail comprising just one inward looking vertical lateral surface. The advantage of the horizontal intersection over the plain flat surface is that in the former the vehicle can make a turn with a substantial speed as the guiding rail sections resist the centrifugal force exerted on the vehicle by turning;

[0043] a horizontal to vertical intersection. The horizontal to vertical intersection comprises what is essentially a modified wall section and a vertical section. The modified wall section comprises strictly straight horizontal rails. Said sections are mounted next to each other with their respective vertical planes laying in parallel to each other. There is a gap between the two sections that enables the vehicle to move through the clearance of the horizontal to vertical intersection along the one or the other section unobstructed or to change direction and transverse from one to the other section. The modified wall section comprises strictly straight horizontal rails and has on its lower rail two sliding pads or two sets of rollers which facilitate transverse movement of the main wheels necessary when the vehicle is changing its direction of movement from horizontal to vertical or vice versa.

[0044] This invention also describes a method of changing the direction of the vehicle, said vehicle in accordance with the description above, wherein said extensions are pair-wise disengaging from a track, or flat base surface, and either engaging with another track or flat base surface, or remain disengaged. As said, the vehicle according to the invention includes a chassis and four wheeled extensions attached to the chassis. Extension has a second member movable about pitch axis by said actuators. The purpose of this composition is to enable the vehicle to engage and align the wheels with the rails of the horizontal guideway or disengage. Thus the vehicle can travel along the uniform sections of the guideway and can choose direction in the bifurcations and in the intersections. In the bifurcations and in the horizontal intersections the vehicle utilizes Mecanum wheels which enable the vehicle to follow sharp curvatures without the need to change the relative positions of its wheels with respect to the chassis i.e. without the need to steer by turning wheels about their vertical axes.

[0045] In the horizontal intersections, when the vehicle needs to turn left or right, it engages and aligns the upper guiding wheels of the corresponding left or right side pair of extensions with the adequate left or right guiding rail section and recesses the other side pair of extensions and thus selects and follows the chosen direction. When the intended direction of the vehicle is straight, both sides of extensions recess and disengage from the upper rails of the both guiding rail sections and the vehicle moves freely in straight direction across the horizontal intersection not turning left or right. When coming across the middle of the horizontal intersection, the lower horizontal guiding wheels optionally engage with the ground rail of the guiding rail section on the outgoing side of the horizontal intersection and thus correct and realign the direction of the vehicle if necessary.

[0046] In the horizontal to vertical intersection when the vehicle needs to change direction it stops first at the center of the intersection. With one side pair of extensions still engaged with the incoming track it stretches across the intersection to reach the outgoing track with the other side pair of extensions. Then it engages the latter with the outgoing track. After that it disengages the initially engaged side pair of extensions and starts moving in the chosen new direction. When the vehicle just needs to pass by the horizontal to vertical intersection it drives through the clearance between the two intersecting tracks of the guideway without any interference.

[0047] With respect to the fixed extensions, the rotational movements of the second member about the pitch axis which engages or disengages the horizontal guiding wheels with said guide rails to either follow one direction or the other and the rotational movement about the same pitch axis which engages said second member with the vertical rail are both performed by the same electric cylinder. The appropriate movement is determined by the piston position feed back to the controlling unit by the potentiometer built in the electric cylinder. Thus the controlling unit can select either the disengagement of the horizontal guiding wheel by the lowest piston position or the engagement of the horizontal guiding wheel with the horizontal rails by somewhat raised piston position or the engagement of the vertical driving wheel set with the vertical rail by the highest piston position.

[0048] Accordingly it is the object of this invention to provide a vehicle capable of negotiating a variety of guideway forms - the most important component necessary to design and implement a freight delivery system that:

[0049] 1— Is easy to build, setup and operate as a fully automated transportation system by those skilled in the art and science of fully automated rail transportation systems or of shop floor carts using conventional automation methods and equipment.

[0050] 2— Is a safer, more efficient, more economical i.e. cheaper, environmentally friendlier, producing less CO2 and faster alternative to a courier, conventional parcel service or pizza boy using fully automated vehicles that move on tracks horizontally and vertically and no one has to drive to deliver all sorts of goods and merchandise anywhere along the tracks and thus as a consequence exchange and commerce of goods could be significantly promoted.

[0051] 3— Can be installed into existing or new buildings in a manner analogous to HVAC ducts allowing vehicles to travel into an office space or a living space in any floor. This could be achieved economically in an island type of installation connecting different rooms in just one building alone or as part of a urban network.

[0052] 4— Allows vehicles to travel from one building to another at any height from the ground or to travel underground using conventional ducts and shafts which can be constructed analogous to a sewage system.

[0053] 5— Is more reliable than the drone based delivery systems as in contrast to drones, it can be protected against elements. In contrast to drones it can deliver within buildings without compromising on safety and comfort of the dwellers. Compared to drones its lifting and descending consumes far less energy.

[0054] BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated by reference to the respective detailed descriptions, when taken in conjunction with the accompanying drawings, wherein (pertaining to the preferred embodiment):

[0056] FIG. la is a perspective view of the vehicle.

[0057] FIG. lb is a front view of the vehicle and of the basic guideway profile

[0058] FIG.lc is a perspective view of the horizontal intersection

[0059] FIG. Id is a detailed perspective view of the horizontal intersection with the vehicle passing through it

[0060] FIG.2a is a perspective view of the front left arm (isometric view front top right). FIG.2b is a perspective view of the front left arm (isometric view front top left).

[0061] FIG.2c is a perspective view of the front left arm (isometric view back top left).

[0062] FIG.2d is a side view of the front left arm

[0063] FIG.2e is the left side view of the front left arm with the raised second member FIG.2f is the right side view of the front left arm with the raised second member FIG.2g is a vertical intersection view of the front left arm with the lowered second member across the middle of the vertical actuator

[0064] FIG.3 is a horizontal intersection view of the front left arm across the middle of the main driving shaft FIG.4a is a perspective view of the vehicle in the horizontal to vertical intersection FIG.4b is a partial top view of the vehicle in the horizontal to vertical intersection FIG.4c is a top perspective view of the bottom frame with the built in yaw movement mechanism

[0065] FIG.4d is a bottom perspective view of the bottom frame with the built in yaw movement mechanism

[0066] FIG.5 is a left side view of the vehicle in the horizontal to vertical intersection FIG.6a is a schematic side view of the linkage mechanism in its leveled horizontal position

[0067] FIG.6b is a partial schematic side view containing a diagram of the relevant forces acting on the leveled linkage mechanism

[0068] FIG.6c is a schematic side view of the linkage mechanism in its inclined position FIG.6d is a partial schematic side view containing a diagram of the relevant forces acting on the left side of the inclined linkage mechanism

[0069] FIG.6e is a partial schematic side view containing a diagram of the relevant forces acting on the right side of the inclined linkage mechanism

[0070] FIG.6f is a detailed diagram of the relevant angles and forces acting on the right side of the inclined linkage mechanism

[0071] (pertaining to the second embodiment)

[0072] FIG.6g is a schematic side view of an alternative linkage mechanism in its leveled horizontal position

[0073] FIG.6h is a partial schematic side view containing a diagram of the relevant forces acting on the leveled alternative linkage mechanism

[0074] (pertaining to the third embodiment):

[0075] FIG.7 is a perspective view of the front left arm (isometric view back top left).

[0076] FIG.8a is a horizontal intersection view of the front left arm across the middle of the pinion axle

[0077] FIG.8b is an exploded view of the pinion wheel assembly

[0078] (pertaining to the fourth embodiment)

[0079] FIG.9 is a vertical intersection view of the vehicle having a recessed movable extension in the horizontal to vertical intersection FIG.10 is a vertical intersection view of the vehicle having a stretched movable extension the horizontal to vertical intersection

[0080] FIG.11 is a partial side view of the rear right arm

[0081] DETAILED DESCRIPTION OF A PREFERENTIAL EMBODIMENT

[0082] The following detailed description of exemplary embodiments of the invention makes reference to the accompanying drawings, which form a part hereof and in which are shown, by way of illustration, exemplary embodiments in which the invention may be practiced. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. Thus, the following more detailed description of the embodiments of the present invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the present invention, to set forth the best mode of operation of the invention, and to sufficiently enable one skilled in the art to practice the invention.

[0083] The following detailed description and exemplary embodiments of the invention will be best understood by reference to the accompanying drawings, wherein the elements and features of the invention are designated by numerals throughout.

[0084] FIG. la illustrates the vehicle 100 on a flat surface. The vehicle 100 comprises the chassis 1 and the left side pair and the right sidepair of the front and the rear extension respectively. Extensions are denoted as front left 2, front right 3, rear right 4 and rear left 5. The designation of extensions as front or rear and left or right follows the arbitrarily assumed direction of vehicle's movement. Each of the front and rear extensions is a mirror copy of its other side pair member. Extensions 2 and 3 are pivotally attached to the chassis 1 by their respective revolute joints embodied as hinges 20 which enable yaw movement of the extension. Extensions 2 and 5 are fixedly attached to the chassis 1. The roll-top doors 95 are partially open, exposing an empty cargo space, the position of the conveyor belt 96, the battery 97 and the motherboard 98.

[0085] In FIG. lb the vehicle 100 is displayed positioned on a horizontal guideway 47 shown in a cross section.. The relevant parts of the horizontal driving wheel set 19 are the traction wheel 15 being in contact with the raised guideway surfaces and the Mecanum wheel 16 being elevated over the recess in the middle of the guideway profile 47. The side surfaces of the profile are engaging the lower guiding wheels 7 in that way being able to guide the vehicle 100 along straight stretches and mild curvatures of the horizontal guideway. The second members 13 of the articulated extensions 2,3 are shown in their lowered positions not stretching out of the outline defined by the chassis 1, save for the small part of the horizontal guiding wheels 6,7 for obvious reasons. Thus the cross section required by the vehicle 100 when traveling in confined spaces like ducts minimally exceeds the outline of the chassis leaving the great majority of the cross section to the cargo space.

[0086] FIG.lc shows a horizontal intersection 250. When the vehicle 100 (not shown in FIG.lc) enters the horizontal intersection 250 at the position A and it needs to turn left or right, it engages and aligns the upper guiding wheels of the corresponding left or right side pair of extensions with the adequate left 251 or right 252 upper rails of the guiding rail section and recesses the other side pair of extensions and thus selects and follows the chosen direction. The upper guiding rails 251 and 252 are composed of two parallel stripes of adequate material. The otherwise structurally needed components like brackets, struts, consoles and similar aren’t shown for the sake of clarity. When the intended direction of the vehicle is straight, both sides of extensions recess and disengage from the upper rails 251,252 of the both guiding rail sections and the vehicle moves freely in straight direction across the horizontal intersection not turning left or right. When coming across the middle of the horizontal intersection, the lower horizontal guiding wheels optionally engage with the ground rail 253 of the guiding rail section on the outgoing side of the horizontal intersection and thus correct and realign the direction of the vehicle if necessary. FIG. Id shows a portion of a horizontal intersection 250 with the vehicle 100 passing from left to right of the drawing and turning right. This direction is arbitrarily chosen for the sake of explanation consistent with the explanation for FIG.1c. FIG. Id could be otherwise also explained as a horizontal intersection 250 with the vehicle 100 passing from right to left of the drawing and turning left. The vehicle 100 shown in FIG. Id has chosen the right direction. To that end it has the second members of the fixed extensions pair risen to engage the right guiding wheels 6R with the right upper guiding rails 252 of the horizontal intersection 250. The other pair of extensions has its second members lowered to let the left upper guiding wheels 6L pass under the left upper guiding rails 251. The movement of the vehicle 100 over the horizontal intersection 250 is achieved by the working of the Mecanum wheels 16 engaged with the surface as they permit the lateral movement necessary for the vehicle to negotiate the curvature. The main traction wheels 16 are risen from the ground surface by the design as their diameter is smaller than that of the Mecanum wheels and thus disengaged since they would otherwise obstruct lateral movement.

[0087] FIGs.2a-2g illustrate extension in its front left 2 embodiment. The extension 2 consists of the first member 12 which is the lower arm, the second member 13 which is the upper arm, the third member 14 which is the docking assembly of the upper vertical guiding wheel 8 and the fourth member which is the gearbox assembly 22. The first member 12 is formed basically as an L shaped cantilever supporting the second and the third member by the respective pivots 21 and 29. The fourth member 22 is pivotally attached to the second and the third member from the opposite side. The fourth member 22 is attached to and pivots around the second member by the two opposite eccentric tensioners 33. The fourth member 22 is attached to the first member 12 by the lower chain 31 and the chain tensioner 25 which slides rotationally over the upper cylindrical surface 24 of the bearing housing 23 thus enabling the pivotal movement of the gearbox assembly 22 around the main driving shaft 50.

[0088] The basic structure of each of said members is embodied as an assembly made up of several parts bolted and pinned together. Other functional parts as for example wheels are attached to each member respectively. The arm 2 is with its first member 12 fixedly attached to the vehicle by bolts fixed through bolt holes 36 and by a pin put through pin hole 35. The second member 13 is pivotally attached to the first member by the pitch hinge pin 21 which enables the pitch movement of the second member 13. The pitch hinge pin 21 is coincident with the pitch revolute joint. The pitch movement is driven by the vertical actuator embodied as an electrical cylinder 17 equipped with a potentiometer enabling the cylinder to assume any position between the fully recessed and fully extended. The third member 14 is pivotally attached to the first member by the hinge pin 29 which enables what is essentially a back and forth movement of the vertical upper guiding wheel 8 attached by an axle to the third member 14. This movement is necessary when the vertical upper guiding wheel 8 needs to engage with or disengage from the vertical rail 45.

[0089] FIGs.2a-2d show the second member 13 in the horizontal position dedicated to the horizontal travel of the vehicle. In this horizontal position of the second member 13, the vertical upper guiding wheel 8 is situated in its front i.e. disengaged position.

[0090] The horizontal upper guiding wheel 6 is rotationally attached by an axle to the second member 13. The horizontal lower guiding wheel 7 is attached by an axle to the first member 12. When in operation as a component of the vehicle 100 traveling over a flat surface, the extension 2 engages with the flat ground via the Mecanum wheel 16 which drives the vehicle in sync with the other Mecanum wheels belonging to the other three extensions respectively. The main traction wheel 15 featuring an inflatable tyre is driven simultaneously with the Mecanum wheel 16 by the same main driving shaft 50. The main traction wheel 15 is of slightly smaller circumference then the Mecanum wheel 16. Thus, the main traction wheel 15 doesn't interfere with the ground, when the vehicle is situated on a flat surface and consequently, the vehicle 100 can move freely around and change direction as determined by the orchestrated rotation of each Mecanum wheel. However, when the vehicle 100 is put on a track with slightly raised side rails, the Mecanum wheel 16 of each extension is elevated above the ground and the vehicle engages with the guideway via the main traction wheel 15 of each extension respectively. Consequently, the vehicle can travel with substantial speeds along the straight or mildly curved stretches of the guideway. In the horizontal position of the second member 13, the vertical traction wheel 11 and the vertical lower 9 and upper 8 guiding wheels remain disengaged. In FIG.2b the main traction wheel 15 is not shown to expose the gearbox assembly 22 with some of its components. The gearbox assembly frame 84 is made up of several parts bolted and pinned together. The brake shaft 85 is attached to the frame 84 by two bearings. Attached to the brake shaft 85 and rotating with it are the brake disc 27, the smaller chain sprocket III 86 (not visible well in FIG.2b) and the larger chain sprocket II 87. Attached to the gearbox assembly frame 84 is the brake caliper 28. The gearbox assembly 22 is pivotally attached to the first member on the lower side via the chain tensioner 25 extending the lower chain 31 and is pivotally attached to the second member on the inner side via the eccentric chain tensioner 33 extending the upper chain 32.

[0091] The driving torque is transferred via the following drive train. From the main driving shaft 50 via the chain sprocket I 86 (not visible in FIGs.2a-f) and over the lower chain 31 to the larger chain sprocket II 87. Then it is transferred via the brake shaft 85 to the smaller chain sprocket no.III 88. Then it is transferred via the upper chain 32 to the larger chain sprocket no.IV 89 (not visible well in FIGs.2a-g). The latter is fixedly attached to the vertical traction wheel 11. The driving torque is enlarged by the ratio of the chain sprockets in this speed reduction mechanism. Since the gearbox assembly 22 is in the middle of this drive train and is pivotally connected to its both sides, the power is transferred from the main driving shaft 50 to the vertical traction wheel 11 in all positions of the second member 13. When some extra braking exceeding the breaking force of the main motor 58 is necessary, then the brake disc 27 is engaged by the caliper 28. The corresponding Bowden cable of the disk brake running form the brake caliper to the bottom of the chassis 1 where the brake actuator is mounted isn't shown for the sake of clarity. The breaking force is transferred via the brake shaft 85 to either side of the drive train.

[0092] FIG.2c exposes the cam 30 and the cam follower wheel 34. The cam follower wheel 34 is attached to the third member 14 and follows the cam 30 embodied as a grove in the second member’s 13 side plate. When the second member 13 is being elevated by the vertical actuator 17, the cam 30 via the cam follower 34 drives the third member 14 with its vertical upper wheel 8 towards its engaged position in the direction of the centre of the vehicle. In the preferred embodiment, the vertical driving wheel set (10) comprises vertical traction wheel 11 and the larger chain sprocket no.IV 89. FIGs.2a-g show the side view of the fixed extension in three relevant positions of the second member 13 corresponding to the three modes of movement characteristic to the vehicle 100. The three relevant positions of the second member 13 are the following: the horizontal position - shown in FIG.2a-d, the elevated position shown in FIG.2e-f and the recessed position - shown in FIG.2g. The three relevant positions are reached by the working of the vertical actuator 17.

[0093] FIG.2d shows the arm with its second member 13 in the horizontal position. The horizontal upper guiding wheel 6 is set parallel to the direction of movement. In this position the horizontal upper guiding wheel 6 is set to engage with the upper guiding rails in horizontal intersections and bifurcations of the guideway thus guiding the vehicle along the selected side of the intersection to follow the preferred direction. It is also in this position that the horizontal upper guiding wheel 6 is set to engage with the upper guiding rails in wall sections and horizontal to vertical intersections either to travel or to resume the travel along the horizontal wall sections after changing the direction from the vertical movement. The third member 14 is kept in the disengaged position by its cam follower 34 constrained by the cam 30. The brake out section of FIG.2d exposes the side view of the upper part of the electric cylinder 17 which is for the purpose of maintaining the horizontal position of the upper arm 13 adequately extended. A cylindrical rod adapter 41 is mounted to the rod end of the electric cylinder 17 to facilitate a smooth slip of the multi-layered leaf spring 40 during the pivotal movement of the upper arm 13 up or down around the pitch hinge pin 21. In this horizontal position of the upper arm 13 the multi-layered leaf spring 40 is slightly bent by the weight of the upper arm 13.

[0094] When the second member 13 is in the elevated position as shown in FIGs.2e-f, the vertical traction wheel 11 comes into working contact with the vertical right rail 45. The third member 14 is moved into the engaged position by the cam follower 34 pushed by the cam 30. This means that the upper vertical guiding wheel is brought into working contact with the inner surface 122 of the vertical rail 45. In FIG.2e the lower arm 12 is shown without the traction wheel 15 and some other components in order to expose the smaller chain sprocket I 86.

[0095] In FIG.2f the electric cylinder 17 is shown fully stretched as needed to push the upper arm 13 to its elevated position. A biasing mechanism 155 is exposed, in this embodiment consisting of the electric cylinder 17, the cylindrical rod adapter 41 and the three-layered leaf spring 40. The working of the biasing mechanism 155 is the following. The pushing force of the electric cylinder 17 is transferred via the cylindrical rod adapter 41 and the three-layered leaf spring 40 to the upper arm 13. The working of the three-layered leaf spring 40 is enabled by the stroke of the upper pin 39 along the compression groove 42. This arrangement enables the requisite initial pushing force of the vertical traction wheel 11 onto the flat contact surface 120 of the outer side of the vertical rail 45 relieving the electric cylinder 17 of the need to exert the pushing force after it reached the final position and thus saves energy and prevents electric overload of the electric cylinder 17. At the same time the elastic energy of the leaf spring 40 is poised to compensate for certain degree of fluctuations of the horizontal vertical rail position with respect to the vertical traction wheel 11 or for some unevenness of the vertical rail’s traction surface 120 during the vertical movement of the vehicle 100. When the second member 13 is in the recessed position as shown in FIG.2g, the whole second member 13 together with the horizontal upper guiding wheel 6 as its most exposed part, lay beneath the upper guiding rails (not shown in FIG.2g) which are laid with a small gap above the top of the vehicle's chassis thus enabling the arm to pass under the upper guiding rails when necessary for the vehicle 100 to change the direction of movement while passing through intersections and junctions. The third member 14 is kept in the disengaged position.

[0096] FIG.3 shows the cross section of the first member 12 cut horizontally through the center of the main motor 58. The main motor 58 is depicted schematically with just two parts -the rotating outer shell 93 and the main motor fixed core 94 (both parts not hatched). The main motor 58 is an outrunner electric BLDC motor which rotates its outer shell 93 and has its core 94 fixed and bolted to the main motor collar 59 which is attached to the main motor console 60 of the first member 12. The Mecanum wheel hub 55 is attached fixedly to the rotating outer shell 93 of the main motor 58. The Mecanum wheel rim 56 carries the rollers 57. The main driving shaft 50 is attached to the Mecanum wheel hub 55 via shrink fit. The chain sprocket I 86 is attached to the main driving shaft 50 and secured against rotating by a machine key. The main wheel hub 48 supports the inflatable tyre 49 of the main wheel 15 and is attached to the main driving shaft 50 and secured against rotating by a machine key. The force of the load pressing on the main wheel tyre 49 is supported by the ball bearing 52 which is inserted into the bearing housing 23. The latter is attached to the bearing console 54. The other relevant components of the first member depicted in FIG.3 are: the outer plate 62, the inner plate 63, the vertical actuator 17 (depicted schematically as composed of one part), the vertical lower guiding wheel bracket 64, the vertical lower guiding wheel 9, the cantilever stem 65 and the hinge lower bracket 67.

[0097] FIGs.4a-b depict the vehicle 100 in the horizontal to vertical intersection of the guideway. The horizontal to vertical intersection comprises essentially a horizontal track and a vertical track. The horizontal track comprises the horizontal upper rail 43 and the horizontal lower rail 44. The vertical track comprises the vertical right rail 45 and the vertical left rail 46. Both tracks are shown with just the relevant elements being in contact with the vehicle. Other structural elements of the guideway like struts, beams, girders, brackets and alike that are not in contact with the vehicle, though may be structurally needed, aren't disclosed. The vertical rails 45 and 46 are shown cut straight in the upper side and the horizontal rails 43 and 44 are shown cut straight in the front side in FIG.4a to expose the profile of the rails. There is a gap between the two tracks which enables the vehicle to move through the clearance of the horizontal to vertical intersection along the one or the other track unobstructed or to change direction and transverse from one to the other track. The vehicle 100 in the FIGs.4a-b is shown as changing the direction of the movement exactly at the position when the vehicle 100 is engaged with both tracks. The process of changing the direction in the horizontal to vertical intersection in case of transition from the horizontal to vertical movement of the vehicle 100 is the following. The vehicle drives along the horizontal track until it reaches the switch position where it stops. All extensions of the vehicle 100 are in their horizontal position and aligned with the chassis 1 while driving along the horizontal track. One side of the extensions is engaged with the horizontal track, the other side of the extensions is unengaged. For the sake of this explanation, it is assumed that the vehicle is traveling from the top left side of FIG.4a towards the bottom right side and thus the vehicle's right side is engaged with the horizontal track. After the vehicle stops, the right extensions 3 and 4 of the vehicle 100 start stretching out synchronously from the chassis 1 being pushed pivotally outwards around their respective yaw revolute joints 20 by the main cylinder 70 (not shown in FIG.4a). This synchronous stretching out of the arms 3,4 moves the whole vehicle across the gap towards the vertical track while keeping it aligned and essentially parallel with the vertical plane defined by the vertical track. Thus, the vertical upper guiding wheels 8 of the left arms 2,5 can pass through the openings in the square G formed profile of their respective vertical rails 45,46. This transitional movement stops when the vertical upper guiding wheels 8 touch the inner surface opposite to the opening of the vertical rails 45,46. At that moment, the second members 13 of both left arms 2,5 start rotating upwards being pushed by their respective vertical actuators. Via the cam 30 and the cam follower 34 (not visible in FIG.4a) this rotation pushes the upper portion of the respective third members 14 inwards and thus docks the vertical upper guiding wheels 8 with the profile of the vertical rails 45,46. By the same rotational movement of the second members 13, the vertical traction wheels 11 engage with the corresponding surface of the vertical rails 45,46. When the right extensions 3,4 are fully stretched out, the left side of the vehicle 100 hangs over the vertical shaft of the vertical track slightly skewed due to its weight inclining the vehicle slightly downwards on the left side. After the vertical traction wheels 11 of the left extensions 2,5 engage with the vertical rails 45,46, the vertical traction wheels 11 are rotated a little just to lift the left side of the vehicle 100 and align it horizontally, simultaneously taking over the weight of the left side of the vehicle and releasing the pressure off the horizontal upper guiding wheels 6 of the right extensions 3,4. Then the vertical traction wheels 11 are halted at that position by the mechanical brake comprising the brake disc 27 and the caliper 28. After that the second membersl3 of the right arms 3,4 are lowered to their respective recessed positions, thus disengaging the horizontal upper guiding wheels 6 of the right extensions 3,4, from the horizontal upper rail 43. Then the right extensions 3,4 are pulled inwards until they are aligned with the chassis 1. Simultaneously with this movement of the right extensions 3,4, the vertical guiding wheels 8,9 (9 not visible in FIG.4a) of the left extensions 2,5 take over the moment of the vehicle's weight. Then the vertical movement of the vehicle 100 can start by synchronously releasing the brake and propelling the vertical traction wheels 11. When the vehicle 100 is traveling in the opposite direction i.e. from the vertical to the horizontal track, the transition process is reversed.

[0098] FIG.4b depicts a detail top view of the two front extensions 2 and 3. The right extension 3 is attached to the chassis pivotally via the yaw revolute joint embodied as hinges 20. The left front extension 2 is shown engaged with the vertical right rail 45 by its vertical driving wheel 11 in pressing against the contact surface 120 coincident with the outer side of the rail 45. The vertical upper guiding wheel 8 and the vertical lower guiding wheel 9 of the front left extension 2 together with their corresponding counterparts of the rear left extension 4 stabilize the vehicle 100 in the horizontal position with respect to the balance of forces acting on the vehicle in the transverse vertical plane. The front left extension 2 is fixedly connected to the chassis. The front right extension 3 is stretched outwards and engaged with the horizontal track. The horizontal upper guiding wheel 6 is engaged with the horizontal upper rail 43. The horizontal lower guiding wheel 7 is engaged with the horizontal lower rail 43 (not shown in FIG.4b as both horizontal guiding wheels 6 and 7 lay exactly one above the other). The rotation of the arm 3 around the hinge 20 is achieved by the movement of the main cylinder bar 68 pushing the extension 3 via pin joint 82.

[0099] In the preferred embodiment, the movements of the front and rear arms belonging to the same side pair are synchronized by the working of the main cylinder 70 as further illustrated in FIGs.4c-d.

[0100] In FIG.4c the main cylinder 70 is mounted with the longitudinal degree of freedom in the bottom frame 74 of the chassis 1. The main cylinder 70 is attached fixedly to the front carriage 71 with its piston 69 and to the rear carriage 72 with its cylinder body 91. Both carriages 71,72 each have a pair of the horizontal guiding wheels 79 and a pair of the lateral guiding wheels 80 which make possible the movement of the piston 69 and the cylinder body 91 of the main cylinder 70 only along its principal axis. Both carriages 71,72 are each connected to their respective cylinder bars 68 by a pin 92. Cylinder bars 68 protrude out through openings in the bottom frame 74 where they are pivotally attached to the front (3 not visible in the FIGs.4c-d) and the rear extensions (4 not visible in the FIGs.4c-d) respectively. When the vehicle is situated in the horizontal to vertical intersection and needs to stretch out its pivotally movable extensions, it is assumed at that moment, that the main cylinder 70 rests with its piston 69 retraced fully (not shown in the FIGs.4c-d). After that the main cylinder 70 starts pushing outwards in both directions since both, the piston 69 and the cylinder body 91 of the main cylinder 70 are movable along the principal axis by their respective carriages 71,72. This causes the stretching out of the pivotally attached side of the extensions around the respective vertical pivots 20.

[0101] The synchronous movement of both said extensions is necessary for the parallel movement of the vehicle with respect to the parallel vertical planes defined by both tracks (horizontal and vertical) which is needed to dock successfully the vehicle with the opposite track. This synchronous movement is achieved with the yaw drive mechanism housed in the bottom frame 74 displayed in FIG.4d. The main components of the yaw drive mechanism are the main cylinder 70, both carriages 71,72, both cylinder bars 68, two pulleys 73 with their respective pulley brackets 76 and the cable 75. The cable 75 is installed to run around both pulleys which have their circumference slightly wider than the width of the main cylinder 70. The cable 75 is attached fixedly to the front carriage 71 on one side (right) of the cylinder 70 with the cable attachment bolts 78 and is attached fixedly to the rear carriage 72 on the opposite side (left) of the cylinder 70. The cable 75 is spanned by the pulley tensioner bolts 77. According to the situation displayed in FIG.4d, when the main cylinder 70 is actuated and extends its piston 69 towards the left upper side of FIG.4d for some distance, the front carriage 71 pulls the right stretch 75b of the cable 75 and thus the rear carriage 72 is pulled towards the right lower side of FIG.4d by exactly the same distance. When the main cylinder 70 is actuated and retracts its piston 69 towards the lower right side of FIG.4d, the front carriage 71 pulls the left stretch 75a of the cable 75 and thus the rear carriage 72 is pulled towards the left upper side of FIG.4d by exactly the same distance. As both sides of the cylinder thus always move for the same distance, front and rear arms that are connected each with one side of the main cylinder 70 travel the same distance and the synchronous movement of both arms of the selected side of the vehicle is achieved.

[0102] FIG.5 illustrates the vertical movement of the vehicle 100 acting as a linkage mechanism 150. For the sake of clarity, the vertical rail 45 is shown partially cut out to expose the position of the extension 2 parts. The vertical movement of the vehicle 100 is enabled by the working of the linkage mechanism 150 here represented as chassis 1 and the first members 12 of the two fixed extensions 2 and 5 acting as one body from the linkage perspective, two second members 13 of the fixed extensions 2 and 5 and two vertical driving wheels 11.

[0103] The vertical rails 45, 46 are in contact with the vertical traction wheels 11 which are pressed against the rails 45, 46 by the force of gravity acting on the vehicle 100 pulling both second members 13 down and towards each other via their respective pitch hinge pins 21. The necessary friction force which enables the vertical traction wheels 11 to propel the vehicle up or to descend it in a controllable manner down the vertical rails 45 and 46 comes from the sharp angle a formed by the line connecting the center of the pitch revolute joint 21 and the center of the vertical driving wheel axle 90 on the one side and the point of contact 126 of the vertical traction wheel 11 with the flat contact surface 120 of the outer side of the rail on the other side. In the preferred embodiment, the contact surface is coincident with the flat outer surface of the G formed rails 45,46.

[0104] FIGs.6a-6e represent, in a schematic form a projection on the vertical lateral plane of the linkage mechanism 150 employed by the vehicle 100 when engaged with the vertical rails 45,46 and resting or moving up or down. All the parts in FIGs.6a-6c are schematic representations of their genuine counterparts composing the vehicle 100. In general, the geometrical proportions of the schematic representations are exaggerated for the sake of clarity, some relevant proportions are however retained.

[0105] The linkage mechanism 150 consists of the compound chassis 151, two lever arms 152 and two vertical driving wheel sets 10. The compound chassis 151 consists of the chassis 1 and of the first members 12 of the two said fixed extensions 2 and 5 as they form one body from the linkage mechanism perspective. Each lever arm 152 is coincident with the respective second member 13 of the fixed extensions 2 and 5.

[0106] The compound chassis 151 contains the center of gravity 153 of the linkage mechanism 150 which is coincident with the center of gravity of the vehicle 100. The vertical driving wheel sets 10 are engaged with the respective vertical rails 45,46. The lever arms 152 are connected to the compound chassis 151 left and right of the vertical plane 154 projected as a line passing through the center of gravity of the vehicle 100 respectively. The left lever arm 152 is connected to the compound chassis 151 on one side and to the vertical driving wheel array 10 on the other over pivot joints A and C respectively and analogously the right lever arm 152 is connected to the chassis 151 on one side and to the vertical driving wheel array 10 on the other over pivot joints B and D respectively. Joints A and B are coincident with the pitch revolute joints 21 of the fixed articulated extensions 2,5. Joints C and D are coincident with the axis of the vertical driving wheel arrays 10.

[0107] In FIGs.6a-6b the position of the chassis 151 is horizontal, laying in the middle between both vertical rails 45,46. The lever arms 152 are tilted upwards at the angle α.

[0108] FIG.6b shows the diagram of the relevant forces acting on a free body of the vehicle 100 in the joints A and C in the lateral vertical plane coincident with a plane normal to the axes of the vertical driving wheel sets (10). The forces in the diagram are shown as vectors with their length corresponding to their relative size.

[0109] In FIGs 6a-6b, the force of gravity Fg produced by the gross weight of the vehicle 100 inclusive cargo is split in half and acts downwards in joint A. Fch represents the reaction force of the rail 45 that acts over the left vertical driving wheel array 10 through joint D, the left lever arm 152 and joint B on the chassis 151. The direction of Fch is towards the joint B. The forces acting in joints A and C are mirrored in joints B and D. Thus the force Fch that acts in joint B in the free body of the compound chassis 151 balances its joint A counterpart Fch. The size of Fch acting in joint A equals the x axis projection of Flink, while its y axis projection equals Fg / 2 to satisfy the balance of forces principle in joint A. In joint A Flink is pulling outwards and so is it pulling outwards in joint C. Fm is the force of motor acting in joint C in the opposite direction of gravity. Fm is a resultant force of the motor torque Mm applied to the wheel array 10, and the traction reaction force Ftr acting on the surface of the rail in the same size and direction as Fm. Neither Mm nor Ftr is shown in the diagram for the sake of clarity. Fn is the normal force acting on the surface of the rail. Fn is the resultant force of Fm and Flink acting in joint C. Fn is balanced by the corresponding reaction force of the rail surface, The latter isn’t shown in the diagram for the sake of clarity.

[0110] In FIGs 6c-6e the position of the chassis 151 is slightly inclined caused by unequal distribution of mass in the vehicle 100. The left side carries significantly more weight than the right side. The forces acting in joints A, B, C, D are of the same nature and are acting in the same direction with respect to the relevant geometrical features of the bodies, however their size and absolute angle change to satisfy the geometrical constraints of said linkage mechanism and the balance of forces and moments required by the equilibrium equations. The forces are hence marked with additional subscript denoting the side of the diagram A or B.

[0111] The principle of this linkage mechanism when in operation is gravity generated normal force needed to produce the requisite traction. This means, that the only outer force acting on the links of the mechanism needed to produce the requisite traction come from the mass (gravity) of the vehicle 100. Initially, this mechanism needs some biasing force to lift the lever arms 152 and bring the driving wheel array 10 in contact with the rails 45,46. When driving, some biasing force is also needed to align the wheel array 10 with the surface in case of unevenness. The biasing mechanism 155 which produces the biasing force can be embodied for example as a hydraulic cylinder which can exert permanent force without much power consumption. In this embodiment the active components of the biasing mechanism 155 are the electric cylinder 17 and the leaf spring 40 where the electric cylinder 17 produces the necessary approach movement and the leaf spring 40 then exert some permanent force big enough to push the wheel array 10 against the surface of the rail 45,46 when the contact could have been otherwise lost due to potential unevenness of the traction surface. However the size of this biasing force just need to overcame the weight of the wheel array 10 and the lever arm 13 and is thus the minor part of the total force exerted on the traction surface in the normal direction.

[0112] The vertical movement of the vehicle 100 employing this central gravity generated normal force linkage mechanism to be successful requires some of its geometrical properties to satisfy the basic equations.

[0113] Following the arrangement in Fig.6b, Fn, the normal force produces the friction force Ff for the movement by the equation:

[0114] Ff = Fn * μ (1)

[0115] where μ represents the coefficient of friction. Ff isn’t shown in FIGs 6a-6e for the sake of clarity. For the equilibrium of forces equations to hold true, meaning for the vehicle to move along the vertical rails with constant speed, the forces acting on the vehicle from the outside must be in balance. If we neglect the rolling friction force, there are only two such forces acting in the vertical y axis, the gravity force Fg and the static friction Ff of the wheel on the surface of the rail. Then the following inequality must be valid:

[0116] Ff ≥ 1 / 2 Fg

[0117]

[0118] From the triangle of forces in the joint A we derive at the following relationships:

[0119] sin (a) = - - Flink F

[0120]

[0121] link~ sin(a) From the triangle of forces in joint C we get:

[0122] F —Fn

[0123] Unkcos (a)

[0124]

[0125] Introducing Ff from (1) into (5) we get:

[0126] F “nk- -g#cFofs(a)

[0127]

[0128] Merging (4) and (6) we get:

[0129] Ff ≥ 1 / 2Fg

[0130]

[0131] g*cos(a) sin(a) Introducing (2) and replacing Ff with Fg we get:

[0132] — 1 p „ = - Ff*sin(a) = - Ff*tan(a)

[0133]

[0134] 2 S ii*cos(a) n

[0135] Introducing (2) into (8) we arrive at the inequality

[0136] Ff ≥ Ff*tan(a)

[0137]

[0138] And using the basic relationship of trigonometric functions we finally arrive at:

[0139] μ ≥ tan(α)

[0140]

[0141] This condition must hold true for the vehicle to employ successfully the gravity generated normal force mechanism principle.

[0142] When the weight of the vehicle 100 is distributed unevenly the positions of the links in the mechanism change as shown in FIGs 6c-6e. To satisfy the geometrical constraints, the compound chassis 151 is inclined slightly for a small angle p, the left lever arm 152 assumes a greater angle ex with the horizontal line and the right lever arm 152 assumes a sharper angle a with the horizontal line as compared to the evenly distributed weight of the compound chassis 151 shown in FIGs 6a-6b.

[0143] FIG.6e depicts in detail the geometrical relationships of the relevant angles and forces for the joint A shown in FIG.6d. The condition for the gravity generated normal force mechanism to function in this situation, based on the balance of forces in the joint C, is the following:

[0144] Ff = μ * FnA ≥ FmA (10)

[0145] From FIG.6f, following the sine rule, we get:

[0146] FgA FlinkA

[0147] sin(a+j8) sin(90°- / ?) And rearranged:

[0148] FlinkA = FgA*sin(90°−β) / sin(a+β) (12)

[0149]

[0150] The balance of forces in the joint C gives:

[0151] FlinkA = (13)

[0152]

[0153] cos (a)v 7Merging (12) and (13) gives:

[0154] Fn FgA* sin(90°— / ?)

[0155]

[0156] cos(a) sin(a+ / ?) And rearranged:

[0157] Fn = FgA*sin(90°−β)*cos(a)

[0158] sin(a+ / ?) 1 1 From the balance of forces in the joint C we get:

[0159] FlinkA = (16) sin (a)v' Merging (15) and (16) gives:

[0160] Fm / sin(a) = FgA*sin(90°−β) / sin(a+β) (17)

[0161]

[0162] sin(a) sin(a+ / ?) And rearranged:

[0163] Fm = FgA*sin(90°−β)*sin(a)

[0164]

[0165] sin(a+ / ?) 1 1

[0166] Replacing Fn and Fm in (1) we obtain the inequality:

[0167] μ*FgA*sin(90°−β)*cos(a) / sin(a+β) ≥ FgA*sin(90°−β)*sin(a) / sin(a+β)

[0168] sin(a+ / ?) sin(a+ / ?) (19) Rearranging (19) we arrive at the final condition:

[0169] μ ≥ tan(α) (20)

[0170] Inequality (20) is the same as inequality (10) which means, that the gravity generated normal force mechanism can successfully operate also in less than ideal situations, when the load isn’t distributed evenly. It should be noted, that due to the geometrical constraints of the linkage mechanism 150 engaged with rails 45,46 and due to the constraints of the equation (20), the vertical position of either wheel (its relative height) can’t vary too much. To that end, the programing of the vehicle 100 must provide control means which cater for the requisite synchronization of acceleration, speed and position of both wheels, basically by accelerating the motor that lags behind or attenuating the motor that leads while driving and making sure that both motors stop synchronically attaining what is basically a neutral position of the line A-B and consequentially of the vehicle 100. The neutral position of the vehicle 100 is one that is coincident with the position of the vehicle according to the distribution of weight between the two joints A and B.

[0171] When the vehicle employs the rack and pinion mechanism for the vertical movement instead of friction based traction wheel 11, the required normal force Fn is expected smaller as it only needs to counteract the radial reaction force of the rack and pinion gears. So, instead of (10), the basic condition for gravity generated normal force mechanism to function changes to:

[0172] Fn > Fr (21) Where Fn is the normal force produced by the gravity generated mechanism and Fr is the radial force generated by the working of the rack and pinion gear mesh. Fr is directed towards the center of the pinion i.e. opposite the Fn. Fr is proportional to Ft. Ft is the tangential force acting along the rack line and represents the actual force of the motor. The ratio of these rack and pinion forces is denoted as:

[0173] rf = Fr / Ft (22) rf depends on the geometrical and some other features of the rack and pinion mechanism. For a simple rack and pinion pair with the common spur gear rf = tan(20°) = 0,364. This is approximately half the value of the friction coefficient of rubber against steel.

[0174] The rest of geometry and forces employed in the working of the rack and pinion embodiment of the gravity generated normal force mechanism are the same as in the case of the friction based variant shown in FIGs 6a-6f. Merging (4) and (5) we arrive at:

[0175] (23)

[0176]

[0177] cos(a) sin(a)

[0178] Rearranging for Fn:

[0179] Fn = 1 / 2Fg*cos(a)

[0180]

[0181] sin(a)v'

[0182] based on the balance of forces for a free moving body in the vertical y direction we have:

[0183] Ft = l / 2Fg (25)

[0184] introducing (22) into (25) we get:

[0185] Fr = ½Fg *rf (26)

[0186] Using (21), replacing Fn with(24) and Fr with (26) we arrive at:

[0187] 1 / 2F?-“s(a)>. rf (27)

[0188]

[0189] sin(a) 2 "7 v 7

[0190] Rearranging and replacing we finally get:

[0191] rf < cot(a) (28)

[0192] In case rf = 0,364 characteristic of a basic spur gear type of pinion and rack combination, the angle ex must be less than 70° as compared to the friction based embodiment where, for the friction coefficient of rubber against steel / z= 0,7, ex must be less than 35°. It should be specifically noted that the above assignments rf=0,364 and / z= 0,7 are not to be taken as absolutely precise but simply to illustrate the likely difference in the design of the two embodiments.

[0193] When in dynamic equilibrium, the reactive force of the acceleration acting in the opposite direction of the vehicle’s movement is a vector acting along the same direction as the force of gravity Fg, meaning that the equations ( 1 )-(28) change by replacing Fgwith the resultant force Fr(Fr= Fg± Fa). However, since Fgis canceled out from (9), (19) and (27), the conditions (10), (20) and (28) hold true also when the vehicle 100 is accelerating or decelerating in going up or down the vertical rails 45,46.

[0194] DETAILED DESCRIPTION OF THE SECOND EMBODIMENT

[0195] The second embodiment is an alternative linkage mechanism with an analogous composition and distribution of forces and the same functionality. It provides the needed normal force for the vertical movement without any external energy source but the weight of the vehicle. Only a schematic representation of the second embodiment is provided. The details could be easily reproduced by a person skilled in the art.

[0196] FIG.6g discloses schematically an alternative embodiment of the linkage mechanism 150. The linkage mechanism of the second embodiment consists of the compound chassis 151, two lever arms 152, and the left and the right trolley 164 each consisting of a trolley arm 161 and a pair of vertical driving wheel arrays 10. Each trolley arm 161 is pivotally connected to the respective lever arm 12 at its distal end by the pivot 162. The wheel arrays 10 are mounted onto the respective trolley arml61 and distributed above and under the respective pivot 162. The position of the pitch pivots 21 lays comparatively lower than on the preferred embodiment to facilitate a complete recess of the upper vertical driving wheel arrays 10 under the horizontal line defined by the upper edge of the compound chassis 151 when needed. The whole composition shown on FIG.6g results in a force diagram FIG.6h that resembles the diagram of the relevant forces from FIG.6b with one alternation. The normal force Fn (shown on FIG.6h just for reference) isn’t actually acting but is split into two components Fwl and Fw2. which are actually acting on the contact surface of the respective wheel arrays 10 and the rail 45. Force Fn is split into Fwl and Fw2 according to the equilibrium of moments and the equilibrium of forces equations for the trolley arm 161.

[0197] DETAILED DESCRIPTION OF THE THIRD EMBODIMENT

[0198] The third embodiment is a modification of the vehicle of the preferred embodiment in that it employs the rack and pinion mechanism for the vertical movement as compared with the preferred embodiment which utilizes friction force. To that end the pinion gear 202 and the roller wheel 204 of the third embodiment replace the vertical traction wheel 11 of the first embodiment and the position of the pitch hinge pin 21 is moved outwards to enable the upper arm 13 to assume a steeper angle resulting in less normal force. The contact surfaces 120 of the vertical rails 45,46 comprise flat outer surface of the rail and the teeth of the rack as compared to the preferred embodiment where contact surface (120) is just the flat outer surface of the rail.

[0199] FIG.7 shows the second member 13 (the upper arm) of the front left extension 2 exposing the pinion gear assembly 201 with the pinion gear 202, roller wheel 204, the larger chain sprocket 89 and the pinion axle 206. In this embodiment the vertical driving wheel set (10) is identical with said pinion gear assembly 201.

[0200] FIG.8a and FIG.8 b show the composition of the pinion gear assembly 201 engaged with the contact surfaces 120 of the rail 45. The motor torque is transferred via the upper chain 32 to the greater chain sprocket 89. The greater chain sprocket 89 rotates on its bearing 209 freely around the fixed pinion axle 206. The torque is transferred over the torque transmission sleeve 205 to the pinion gear 202. The three components are fixedly bolted together by six torque transmission bolts 211. The pinion gear 202 rotates on its double bearing 208 freely about the fixed pinion axle 206. The motor power is transferred from the pinion gear 202 to the rack 203 which is mounted with bolts on the vertical rail 45.

[0201] The normal force, which is a component of the force of gravity acting on the vehicle, is conveyed also via the roller wheel 204 onto the flat surface of the vertical rail 45. The roller wheel 204 is rotating freely around the torque transmission sleeve 205 on its needle bearing 207. Said normal force counteracts and is greater than the radial force produced by the working of the rack and pinion mechanism and consequently the upper arms 13 remain engaged with the vertical rails 45,46 and the vehicle can move upwards or downwards in controllable manner. The needle bearing 207 of the roller wheel is kept in its position with the retainer ring 212 and a spacer.

[0202] DETAILED DESCRIPTION OF THE FOURTH EMBODIMENT

[0203] The fourth embodiment is a modification of the vehicle of the preferred embodiment in that it employs linear guides for the horizontal stretching out of the extensions as compared with the preferred embodiment which utilizes pivots. To that end the linear guides 300 replace the yaw revolute joint 20 and the movable stem replaces the hinge stem 65 and hinge brackets 67

[0204] FIG.9 shows the vehicle in the horizontal to vertical intersection with its front left 2 arm engaged with the vertical rail 45 and its front right arm 3 in the recessed position aligned with the outline of the chassis 1. The upper arm 13 of the second extension 3 is also in the recessed position aligned with the outline of the chassis 1. The linear guides 300 consist of two linear guide shafts 301 attached fixedly to the chassis 1 on both sides and two linear bushings 303 attached fixedly to the movable extension 3. The linear actuator 305 is attached to the bracket 311 with a pin on the rear side and also attached with a pin to the movable stem 307 on the front side. The bracket 311 is fixedly attached to the chassis 1. There is an opening in the fixed stem 309 making room for the linear actuator 305 which thus does not engage with the fixed stem 309. In this position of the extension 3, the linear actuator 305 rests in its recessed position. The horizontal to vertical intersection consists of the vertical rails 45 and 46 (the left vertical rail 46 not visible in the FIG.10), the horizontal upper rail 43 and the horizontal lower rail 44.

[0205] FIG.10 shows the vehicle in the horizontal to vertical intersection with its front left extension 2 engaged with the vertical rail 45 and its front right extension 3 engaged with the horizontal rails 43 and 44 of the horizontal to vertical intersection. The movement of the left front extension 3 outwards towards the horizontal rails 43 and 44 was achieved by the working of the linear actuator 305 extending its piston. Under the pushing force of the piston of the linear actuator 305, the movable stem 307, utilizing its upper and lower bushings 303, slides along the upper and lower linear shafts 301 to its extended position thus mowing the whole front left extension 3 outwards to engage with the horizontal upper and lower rails 43 and 44 respectively. The programming of the vehicle performs the horizontal transverse movement of the extension 3 with its upper arm 13 in the recessed position. After the horizontal transverse movement reaches its outermost position, the pivotal movement about the pitch hinge pin 21 of the upper arm 13 follows which engages the upper 8 and lower horizontal guiding wheel 7 with the horizontal rails 43 and 44 respectively. The design of the vehicle 100 is symmetrical with respect to the front and rear extensions. Each side pair of extensions (left or right) consists of two arms which are mirror forms of each other. Also the setup of the horizontal linear actuator 305 is mirrored on the front and rear side of the vehicle 100. Thus the programming of the vehicle achieves that the horizontal linear actuators 305 on both sides (front and rear) act simultaneously resulting in a synchronous and parallel movement of the chassis 1 in order to avoid its collision with the vertical rails 43 and 44.

[0206] FIG.11 shows the rear right arm 4 in the recessed position of its second member 13. The horizontal linear actuator 305 is embodied in an electrical cylinder positioned approximately in the middle of the movable stem 307 in order to spread its pushing or pulling force evenly between both linear guide bushings 303.

Claims

PATENT CLAIMS1. A vehicle (100) comprising a chassis (1) and four articulated extensions (2, 3, 4, 5), wherein, with respect to the direction of the horizontal moving of the vehicle, two of said extensions (2,3) are positioned in front of a transverse vertical plane running through the center of gravity of the empty vehicle and two of said extensions(,4,5) are positioned behind said transverse plane thus dividing the extensions into the front extensions and the rear extensions respectively, one said front extension and one said rear extension being positioned to the left of a lateral vertical plane running through the center of gravity of the empty vehicle perpendicular to the transverse pane and one said front extension and one said rear extension being positioned to the right of said lateral plane thus dividing the extensions by their side into the left and the right side pair respectively, two first members (12) of the articulated extensions of one said side pair (3,4) being movable, the type of connection chosen from:a. the first member (12) connected pivotally to the chassis (1) by a yaw revolute joint (20) essentially rotating about the yaw axis, b. the first member (12) connected translationally to transverse linear guides (300) essentially moving horizontally in transverse direction and the two articulated extensions of the other said side pair (2,5) being fixed extensions with the first member (12) fixedly connected to the chassis (1), said four extensions having a second member (13) pivotally connected to the first member by a pitch revolute joint (21) essentially rotating about the pitch axis, further comprising four or more main horizontal driving wheel sets (19) wherein each set comprises only wheels rotating about the same axis and at least one said main horizontal driving wheel set is with its respective bearings (52) fixedly attached to each first member (12), further comprising two vertical driving wheel sets (10) wherein each set comprises only wheels rotating about the same axis and at least one said vertical driving wheel set is attached to the respective second members (13) of the fixed extensions side pair (2,5), further comprising control means for controlling movements of each said movable member.

2. The vehicle (100) according to claim 1 wherein when the vehicle (100) is moving horizontally and straight, said extensions are positioned in front of or at the back of said chassis (1) not stretching out of the hypothetical envelope determined by the transverse cross-section of the chassis and the direction of moving save for the minimal projections of the driving and guiding wheels.

3. The vehicle (100) according to claim 1 further comprising eight or more horizontal guiding wheels (6,7) wherein at least two of said main horizontal guiding wheels are attached to each extension.

4. A linkage mechanism (150) comprising a compound chassis (151), two lever arms (152) on their proximal side pivotally connected to the compound chassis (151) by the respective first pivot, essentially a pitch revolute joint (21) and two vertical driving wheel sets attached to said lever arms (152) on their distal side, the type of said vertical driving wheel set chosen from:a. one array of vertical driving wheels (10) having only wheels rotating about the same axis, said axis acting as a second pivot to said lever arm (152)b. a trolley (164) comprising two or more of said vertical driving wheel arrays (10) and a trolley arm (161), said arrays (10) mounted to the trolley arm (161) above and under the trolley pivot (162) with axes in parallel, said trolley pivot (162) coincident with a second pivot of said lever arm (152)wherein said linkage (150) has two joints coincident with said pitch revolute joints (21) and two joints coincident with said second pivot, said linkage (150) having its projection onto a lateral vertical plane normal to said axes in the middle and the projections of said pitch revolute joints (21) positioned to the left and right of a transverse vertical plane (154) defined by the center of gravity (153) of the linkage (150) respectively with said arms (152) stretching outwards tilted upwards at an angle a on each side and said linkage (150) enabled by said angle ex, while said vertical driving wheel sets (10) are engaged with verticalrails (45,46) by the pushing force of the biasing mechanism (155), powered and rotating, exerts enough normal force onto the contact surfaces (120) of said rails (45,46) to hold said wheel sets (10) against said rails (45,46) by the gross weight of the vehicle (100) inclusive cargo alone in excess of the pushing force of the biasing mechanism (155).

5. The linkage mechanism (150) according to claim 4 further comprising control means for controlling and synchronizing the rotation of said vertical driving wheel arrays (10).

6. The linkage mechanism (150) according to claim 4, wherein said vertical driving wheel arrays (10) comprise one or more vertical traction wheels (11) per axis.

7. The linkage mechanism (150) according to claim 4, wherein said vertical driving wheel arrays (10) comprise one or more of each pinion gears 202 and roller wheels 204 per axis.

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