Patent Publication Number: US-2021170285-A1

Title: Coaster and trolley system and method

Description:
RELATED APPLICATION 
     This application: is a divisional of U.S. patent application Ser. No. 15/808,750, filed Nov. 9, 2017, and scheduled to issue as U.S. Pat. No. 10,835,834 on Nov. 17, 2020, which claims the benefit of U.S. Provisional Patent Application Ser. No. 62/420,445, filed Nov. 10, 2016 and claims the benefit of U.S. Provisional Patent Application Ser. No. 62/515,387, filed Jun. 5, 2017, all of which are hereby incorporated by references in their entireties including all Figures and Appendices pertaining thereto. 
    
    
     THE FIELD OF THE INVENTION 
     This invention relates to amusement rides, and more particularly, roller coaster types of rides. 
     BACKGROUND 
     Amusement rides come in many forms and designs. Carousels have existed for many years. The Ferris Wheel debuted at a World&#39;s Fair in Chicago, where it lifted people high into the air in seats as gondolas that pivoted to maintain their orientation as the wheel itself rotated on an axle. A seemingly endless series of rides has been subsequently installed at amusement parks and carnivals. Many rely on a car that moves in relative motion with respect to a deck, support pillar, track, or the like. 
     Notably, electric motors or internal combustion engines may rotate arms on which cars or gondolas are connected to move in simple or complex relative motions, including rotation, translation, both, or multiple combinations of either or both. Meanwhile, coasters have developed as train-like devices in which several cars are connected to a pair of rails arranged as a track. They rise to a maximum height and then descend in undulating motion, rising and descending over and over as the potential energy of altitude is repeatedly converted to kinetic energy and recovered as potential energy. The cars rise and slow down, then drop and speed up, repeating until friction and drag consume all the momentum. Various twists and turns may be engineered into the track controlling the motion of cars. 
     More recently, large systems of rails have been constructed with more complex turns, loops, inversions, and support systems to render those motions possible. Coasters are colossal in height and tortuous in traverse. Also, unique support schemes have been developed. For example, U.S. patent application Ser. No. 12/238,245 (Pub. No.: US 2009/0078148) filed on Sep. 25, 2008 and entitled SUSPENDED COASTER RAIL APPARATUS AND METHOD is hereby incorporated herein by reference in its entirety. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the foregoing, in accordance with the invention as embodied and broadly described herein, a method and apparatus are disclosed in one embodiment of the present invention as including, in certain embodiments, a coaster system with adjustable wheel assemblies, eddy current braking, a static universal joint for easily aligning track with supporting structures thereabove, and more degrees of freedom for a rider that need be engineered into the track and trolley. 
     For example, adjustable wheel assemblies may use a cam-type of axle that is mounted eccentrically by a bolt and a set screw. The bolt serves as an internal axle on which the main axle bears. Accordingly, the main axle that carries the wheel may be rotated eccentrically about the bolt or camming axle mounted to the frame or a bracket connected to the frame. 
     Accordingly, with a set screw that extends parallel to the mounting bolt (mounting or camming axle), the wheel main axle may be rotated eccentrically to move closer or farther from the contact surface against which the wheel or roller rides. Accordingly, the wheel or roller may be adjusted in its distance from that contact surface on the track. The wheel may be stabilized by fixing the wheel axle against the frame or bracket by threading the set screw inward through it, extending parallel to the bolt and stopping against a frame or bracket to which it is secured. 
     Each side (laterally, left and right), considering the front or end of a trolley to be the portion facing in the direction of travel, will carry magnets. Those magnets are mounted on a ferrous metal bracket (a magnetic flux guide) extending in the direction of travel along each side of the frame. These brackets may be adjusted up and down in order to modulate the vertical extent of engagement of the magnets contained thereon with an eddy current plate extending in the direction of travel and made up of ferrous and non-ferrous, but electrically conducting in every event, metal. 
     By adjusting the height of engagement (vertical overlap) therebetween, one may adjust the engagement of the electromagnetic magnets with the eddy current plate fixed with respect to the track and permitting the trolley to pass therethrough subject to a resistance force. Accordingly, the amount of eddy current generation due to the “Lorenz effect,” and therefore the amount of mechanical resistance for braking, may be adjusted (changed, modulated). 
     A tow shaft or engagement arm may extend from a lift trolley to engage a rider trolley, or vice versa. Likewise, various axles are created with pins or bolts. Axles have keepers, such as cotter keys or cotter pins as they are conventionally called extending normal (perpendicular) to the axial direction of each carrier pin or axle. Accordingly, these cotter pins may be easily inserted and removed as required to keep or release the axle pins. Alternatively, or in addition, axles may be bolts secured by nuts protected by Jam nuts, cotter pins, or friction elements against disassembly. 
     In one embodiment, a trolley in accordance with the invention may feature a damper operating similarly to a shock absorber extending from a lower rider support frame (yoke assembly) and connecting to the upper track riding (trolley frame) portion. The lower rider carrier (yoke assembly) portion may pivot on an axle, such as an axle extending longitudinally (in the front-to-back direction) along the length of the trolley. This axle may permit side-to-side (lateral) swinging or pivoting of the suspended harness (seat, webbing structure) and rider therebelow. 
     Nevertheless, in order to dampen or ameliorate this side-to-side (lateral) swinging, a damper (viscous liquid forced through an aperture by a piston) or shock absorber may connect between the trolley portion that is the track rider and the lower yoke assembly that acts as a rider support for slings and webbing (seat) the person sitting in the harness. Accordingly, side-to-side swinging is dampened. Also, the faster this lateral (side) motion operates, the more force is engaged in a viscous. 
     In one currently contemplated embodiment, a spreader bar or end plate of the yoke assembly may extend across each end of the trolley to maintain the distance apart of supporting slings that carry the harness or chair in which a rider reposes. In one contemplated embodiment, apertures are provided proximate each end thereof extending laterally away from the track. The apertures may receive carabiners or other connectors to suspend the slings, straps, webbing, harness, seat, or a combination thereof suspending therebelow. One of these end plates, hanger brackets, or spreader bars is positioned proximate the front of the trolley. Another is located proximate the rear of the trolley. With a seat or harness having three or four vertical slings connected to the yoke assembly, fore-to-aft pendulum motion is virtually eliminated. Swinging due to accelerations and decelerations may likewise be ameliorated or otherwise minimized for rider comfort and safety. 
     In certain embodiments of a trolley in accordance with the invention, the frame represents an assembly of components fixed with respect to one another to operate in solid or rigid-body motion. That is, the frame represents a substantially solid or rigid body in motion along the track. However, the yoke assembly (harness carrier) may operate in substantially rigid body motion fore-to-aft and up and down with respect to the frame, while yet being able to freely swing laterally (side-to-side). The track thus becomes a reference path along which the trolley operates under the influence of momentum and gravity. A rider in a seat moves with the trolley forward and vertically up and down. However, a rider pivots with the yoke assembly in a “roll” direction on turns. 
     In certain embodiments, a chain, such as a sprocket chain may operate along a lift rail connected to be rigidly parallel to a portion of the main carrier track. The chain has one link or more modified to contain an engagement member to engage a lift trolley, which then lifts the rider or carrier trolley. A lift trolley may be moved forward and upward, lifting the main carrier trolley, then return. Alternatively, as an engagement arm or member on the chain passes a lift trolley, an engagement member on the lift trolley may engage the engagement arm or member of the chain. 
     Whether the link of the chain is temporarily or permanently fixed to the lift trolley, the lift trolley contains an engagement arm to engage a corresponding engagement arm on the carrier trolley to carry a rider on the main carrier trolley up an incline to begin coasting down. Accordingly, the chain engages the lift trolley, and the lift trolley engages a carrier trolley. 
     At some point past the top of a ramp portion of the carrier track, the lift track may diverge from the carrier track, thus disengaging very simply and straightforwardly, and especially reliably, from the carrier trolley. The carrier trolley is then free to descend under the influence of gravity as a coaster along the carrier track. The lift trolley may reverse direction with the chain and return to its starting location or move there on a continuous loop of chain. 
     The engagement arm on the chain may be a bracket that is manufactured in, as, or on a modified link in the chain. Thus, the chain may operate continuously in a single direction tending to lift. In the presence of a lift trolley, may engage and operate to draw the lift trolley up to and along the ramp area in which the lift track parallels the carrier track. Accordingly, the lift trolley is engaged by the chain as a source of power, and itself then engages the carrier trolley to lift a rider up the ramp portion of the carrier track. 
     One benefit of an integral pickup or engagement arm on a chain is the relieving of an operator from having to pay attention to starting and stopping or engaging and disengaging a chain, a lift trolley, or the like. Instead, the presence of a lift trolley simply operates automatically. A lift trolley may simply be engaged automatically when it is present. 
     Magnets are set in an array extending in length in an axial (longitudinal, travel) direction. They have width in a vertical or transverse direction, and may stack in a lateral (side) direction. They will be mounted on a ferrous material as the bracket that secures them to the trolley. This tends to improve the operation of the magnets by acting as a flux guide. 
     A magnet array may be established at location and have a particular length, along the direction of travel, in order to provide the amount of spatial engagement (overlap), the amount of eddy current braking available, and so forth. Likewise, the magnets may be spread out over any greater or lesser length and may be distributed along a greater or lesser height along their bracket that holds them. 
     Similarly, magnets may be stacked to increase the magnetic flux therethrough. Stacking would effectively stack the magnets to extend farther in a lateral direction. A longitudinal or axial direction along the track is the direction of motion of a trolley carrying the rider. Laterally means left or right, and transverse is vertical, the three directions being orthogonal. 
     The magnets may extend in a longitudinal or axial direction as a strip of magnets on a bracket on each side of a carrier trolley. They may extend laterally in stacking, vertically in width, as well as adding along their longitudinal extent. All of these extents to which magnets may be laid out and supported on the bracket may be used to control engagement and force provided by eddy current braking. 
     In some embodiments, a trolley may include various eyes, apertures, or the like in order to provide a connection point to move a trolley along a track. For example, one may choose to lift vertically, by a lift eye-bolt, a trolley to mount it on the track or to draw it longitudinally from a storage location thereon to an active track. Meanwhile, an eye-bolt or an eye-shaped carrier for a bearing may operate to support the front-to-rear axle of the harness bracket suspended below the carrier trolley. 
     In short, the trolley contains everything required for carrying a rider, and operates to contain its own braking built into it. Meanwhile, a lift track that extends up parallel to a ramp portion of the carrier track contains everything required to lift the carrier trolley supporting a rider. Similarly, the carrier trolley under which the rider is suspended in a harness or seat has the ability to decelerate itself as it passes by eddy current plates constituting braking areas at any portion of the track where desired. Braking may be used particularly before sharp or high-speed turns, or near the end of a ride, in order to assure that momentum (mass times velocity) has been decreased to a safe level. 
     In certain embodiments of an apparatus and method in accordance with the invention, a supporting frame above a track may involve posts or pillars that operate to extend vertically from an underlying supporting surface. Across these base posts or pillars may be affixed lateral beams that extend horizontally. These lateral beams may be considered stringers and may be gusseted at their ends and provided with brackets for securing one component (e.g., length, segment) of track to the next. Accordingly, individual turns, rises, declines, loops, and the like may be made in pieces that may all be connected axially together. 
     Typically, track may be a lower flange of an I-beam or lower tubes in a truss. The track of tubular members that actually operate as the track may be two lower tubes extending longitudinally in a truss. The supporting top tube may be maintained in cradles that fit the diameter of the tubing. These may clamp around the top tube at various sites, or may be welded thereto in order to secure firmly the top tubing in a truss of a tubular track. The tubular track may be considered “a truss track” inasmuch as multiple tubes, typically one top tube and two bottom tubes may be periodically connected together by struts. Struts spacing them apart and holding them together in a rigid embodiment provide minimum weight and maximum strength and stiffness. 
     One may think of cradles to support the track as a beak having an upper and lower half, which halves have an inside diameter matched to the outer diameter of a top tube in a truss track. Accordingly, the top tube is maintained within two halves cut lengthwise along the length of their circular cross-sectional tube in order to be bolted together around the top tube of the track, welded, or the like. 
     To the extent that any particular tube may need to be shaped to have curvature to extend up, down, left, or right as that tube on that track progresses along the path, the beak or support clamp that operates as a cradle may likewise itself be shaped to match. 
     Meanwhile, a frame or support template may be placed periodically between the upper, and lower, tubes and between the two lower tubes. It provides the exact spacing and increases stiffness in the structure that becomes the truss track. 
     The supporting stringers or beams, from which cables suspend the track, will typically not be in danger of striking or being struck by the rider. The vertical posts or pillars may need to be carefully spaced in order that a rider swinging wide on the outside of a turn (or returning back inward) does not accidentally strike a supporting pillar. Thus, a pillar closest to the track should typically be located on the inside of a turn. 
     All track and beam connections may use a double (two-dimensional) shear design (e.g., vertical and horizontal) in order to increase the rigidity and durability of the track and its supports. Accordingly, as illustrated, end plates extend along the ends perpendicular (normal) to the direction of travel and the direction of progress along any track. Likewise, in some embodiments a horizontal and a vertical plate are either formed (e.g., angle iron), bent, or welded together in order to provide full shear support normal to the axial direction on ends of I-beam types of pillars, beams, and tracks, as well as the internal frames in truss tracks. A collar system, typically manufactured in two pieces permits aligning the lower tubes with the top tube quite simply by way of slots formed in the individual halves of the split collar. 
     Applicant discloses a system and method for use of a coaster and trolley system. The coaster track may be suspended in a manner that allows the rider to feel like they are floating through the ride without the conventional tracks and supporting structure below. 
     A Lift System may comprise a chain (e.g., sprocket chain) with protrusions. The protrusions can be either bent tabs, or rods off a link. The link may have such features on both the left and right hand side of its outer plates. 
     The chain may be attached onto a motor by a driving sprocket, and provided with “idler sprockets” to guide and tension it. It may engage the lift trolley or the carrier trolley directly, by contacting a tab or bar extending from a chain link to fit against a swing arm held by a bracket or stop. The link&#39;s tab or bar pushes the swing arm of the carrier trolley against the stop bracket, which forces the trolley to move forward along the direction of movement of the chain. This action forces the carrier trolley to climb a ramp. When the climb is complete the ramp may level off and will next descend. The chain link is rotated away either laterally or transversely (down) from its contact position against the bracket. The trolley continues off, past the tangent of the ramp bend and is acted upon by the gravitational field. 
     The chain can be continuously operated in a loop. The trolley is engaged when it is pushed toward past the link tab or bar, after which the swing arm drops down engaging the link bar or tab. This eliminates the need for any start-stop operation, processing more customers through the ride. 
     In another embodiment, a lift trolley (or a push trolley) may operate in parallel with (or proximate) a ride trolley. The lift trolley and ride trolley may be on parallel tracks, but other configurations are possible. 
     The ride (carrier) trolley may suspend a harness for a rider. The ride trolley may travel the entire length of the ride and may be in a circuitous formation of some sort. The ride trolley may engage with the lift trolley in a manner that moves the ride trolley to a designated or desired point along the track. 
     Generally the ride trolley may stop at a point where riders can be interchanged unloaded and loaded. Then the lift trolley will move the ride trolley up or to a certain portion or position of the track where the ride trolley may continue along a track without further assistance from the lift trolley. In one embodiment, the ride trolley may include a horizontal arm or horizontal beam that is capable of engaging the lift trolley. The ride trolley may move alongside the lift trolley and the horizontal arm of the ride trolley will move or rotate a tab (e.g., ratchet, no-back member) on the lift trolley. The tab may rotate or move in a forward manner. 
     Once the ride trolley is in front of or beyond the tab, the tab may rotate into a fixed position (or engagement position). Then, the lift trolley may engage the ride trolley by moving forward in a manner where the tab engages the horizontal arm (e.g., simple bar or tube of rectangular or circular cross-section), but now the tab is stopped from rotating back, and the tab pushes the horizontal arm, thus pushing the ride trolley. 
     Track may have installed beside and spaced away from it a Ferrous-Non Ferrous Brake combination or pair of layers at a specified ratio of 1:2 for up to 0.5″ (1.27 cm) thick Non-Ferrous metal. Magnets are packed against each other to create the maximum magnetic flux. Drilled holes within the Non-Ferrous and/or Ferrous metal, may reduce the braking force, allowing modulation. Movable brackets may allow for adjustment of an “air gap” between the Non-Ferrous plate (current plate) and magnets, adjusting the braking power. 
     A parallel configuration increases the braking force per length of track. A cam activated braking system may be incorporated by that configuration in the case of chain failure or power outage. Non-adjustable, load-bearing, wheels are fine on the top of the trolley or cart, but an adjustable wheel contact position is best on the bottom and the side rollers. 
     The rear to front attachments reduce swing of the passengers and a deliberate trolley descent along the track. Applicants have also disclosed a joint for use in the track system. The track joint allows for correction of a tremendous amount of potential for misalignment in the track system for maintaining track integrity. The holes in the joint allow for essentially 360 degree angled misalignment in a horizontal plane parallel to the floor, of the track, as well as an inch or so of misalignment in every other direction. To attach to the track, circular slots in a “static universal bracket” match up with a plate with circular slots fixed on the track. To attach to the support structure, a plate with straight slots (in the “static universal bracket”) attaches on a “Support beam assembly” having a plate with slots oriented orthogonally across those in the “universal.” The ends of the support beams can be independently adjusted up or down, allowing the structure to even compensate for rotational misalignment. 
     A method of installation and operation may include providing a course track defining a longitudinal direction, lateral direction, and transverse direction mutually orthogonal to one another at any point along the course track; providing a ride trolley fitted to ride on the course track; providing a lift track; and providing a lift trolley, drive motor, and connection strand such as a chain or belt. 
     Thereafter, the process may include mounting the ride trolley onto the course track; mounting the lift trolley on the lift track; and engaging the ride trolley by the lift trolley to move both under the influence of the drive motor on the lift trolley through the connection strand. At some point an operator may load a rider into a harness, thus suspending a rider from the ride trolley. The system then moves the rider up a ramp portion of the track, to be released to pass through lateral, transverse, and longitudinal translation with the course track and in roll (about a longitudinal axis) outside the path of the course track about a longitudinal axis. 
     The method may include braking the trolley by eddy current braking. The braking system may include a magnet secured fixedly to one of the ride trolley and the course track and a current plate spaced away from the magnet on the other of the course track and the trolley. Adjusting the eddy current braking may include adjusting a clearance between the current plate and the magnet or array of magnets stacked in up to three dimensions. 
     The method may include varying the clearance in a lateral direction with distance along the current plate in a longitudinal direction. This may be done dynamically by varying the clearance based on speed of a trolley approaching engagement of the magnet with the current plate, or based on an input of rider weight measured, sensed, or input by an operator or rider. One may provide control of the clearance empirically based on testing and measuring the effect of a weight of the loaded trolley against the rail. Load may be deadweight or an actual a rider. 
     A static universal may connect between the track or rail and a mounting location adjustable in four degrees of freedom. Four degrees of freedom for aligning and connecting a bracket on the track to a bracket on the supporting frame system may include three degrees of freedom in translation and one of rotation. In one embodiment, the three degrees of freedom in translation are mutually orthogonal. They may be oriented to vertical with gravity. Two of the degrees of freedom in translation may be provided by apertures elongated orthogonally with respect to one another. A third degree of freedom may be represented and adjusted by a fastener through the crossover location of the orthogonal apertures. 
     A method may include damping to control a rate of rotation (roll) of a rider in harness suspended from a pivotable yoke assembly suspended from the frame of the trolley, and thus relative motion with respect to the trolley frame and its track rail. 
     One embodiment of a system consistent with the invention may include an apparatus including a track defining longitudinal, lateral, and transverse directions. A trolley having a frame operable along the track to move longitudinally thereon may include a yoke pivotable with respect to the frame about a longitudinal axis. A harness suspended from the yoke may be capable of moving in translation in three degrees freedom, up and down, right and left, and forward (usually not backward, although possible). A fourth degree of freedom constitutes rotation independent from the translation motions and degrees of freedom. 
     An eddy current braking system may be constituted by a magnet, fixed with respect to one of the trolley and the track, and a current plate fixed with respect to the other of the track and trolley. 
     A framing system supporting the track below a framing system of support may connect therebetween by a static universal joint or static universal connector. The “universal” is positionable, between and with respect to the framing system and the track in three degrees of freedom in translation, mutually orthogonal to each other, and in one degree of freedom constituting rotation, to fix the track with respect to the framing system. The four degrees of freedom are for alignment during installation, and are eventually locked down by fasteners to become rigid. 
     The trolley frame and pivotable yoke suspended therebelow may connect by a bearing system, and also by a damper secured between the frame and the yoke. The damper may be operable to control a pivoting motion of the yoke with respect to the frame, based on a pendulous motion of a rider with respect to the frame while suspended from the yoke. A rider is theoretically a pendulum, but the angle of motion is not the small value required for the pendulum equations and parameters to apply exactly. Also, friction is not insignificant, nor is air drag against a rider and seating harness system. 
     When an eddy current braking system is used, including a magnet and a current plate interacting between the trolley frame and the track, it may be automatically and dynamically controlled based on rider weight, trolley speed on approaching the current plate, or both. A static setting may be made once for the ride, made once for a rider, or be made dynamically based on sensors detecting speed, weight, or both. 
     A framing system supporting the track may ease installation by using the static universal positionable between and with respect to the framing system and the track, in three degrees of freedom in translation, mutually orthogonal to each other, and in one degree of freedom constituting rotation, to fix the track with respect to the framing system. A damper operable between the frame and the yoke to control a rolling motion of the yoke and a rider suspended thereby, may be adjusted or tuned to provide a precise control of oscillation or swinging out (roll) based on pendulum characteristics of the trolley, harness seat system, and rider. 
     A harness suspended from the yoke supports a rider moving in three translational degrees of freedom along the track and mutually orthogonal to one another, and in a rotational degree of freedom with respect to the frame of the trolley. 
     Where an apparatus as a coaster includes a track, trolley moving longitudinally thereon, and a yoke and frame constituting the trolley, the yoke is best made pivotable with respect to a frame about a longitudinal axis (the direction of travel). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects and features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Appendix A contains all figures referenced herein. Appendix B includes a user&#39;s manual, and pictures of the track system, trolley system, harness, and related aspects of the present invention. All appendices are hereby incorporated into this disclosure. 
       Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which: 
         FIG. 1  is a perspective view of one embodiment of a layout for a coaster system in accordance with the invention; 
         FIG. 2  is a partially cut away view of an alternative embodiment of a coaster system in accordance with the invention inside a building with the supporting overhead beams illustrated; 
         FIG. 3  is a perspective view of an alternative embodiment of a multiple level support and rail system for supporting a coaster in accordance with the invention; 
         FIG. 4  is a top plan view of yet another alternative embodiment of a configuration for a coaster in accordance with the invention; 
         FIG. 5A  is a perspective view of a portion of a carrier track associated with a lift track in accordance with the invention; 
         FIG. 5B  is a side elevation view thereof; 
         FIG. 5C  is a top plan view thereof; 
         FIG. 6A  is a perspective view of one embodiment of a supporting, adjustable coupling for supporting a track in accordance with the invention; 
         FIG. 6B  is a perspective, exploded view thereof, illustrating the components contained therein; 
         FIG. 7  is a top plan view thereof; 
         FIG. 8  is a front elevation view thereof; 
         FIG. 9  is a side elevation view thereof; 
         FIG. 10  is a perspective view thereof installed to connect an overhead beam to a curved portion of a suspended rail therebelow; 
         FIG. 11  is a perspective view thereof installed to connect an overhead beam to a straight portion of a suspended rail crossing diagonally therebelow; 
         FIG. 12A  is a top plan view of one embodiment of a supporting cable system for supporting the track in accordance with the invention; 
         FIG. 12B  is a side elevation view thereof; 
         FIG. 13  is a perspective view of an alternative embodiment of a track in accordance with the invention, with a particular embodiment of a trolley or car mounted thereon; 
         FIG. 14  is a perspective view of a different embodiment of a car or trolley in accordance with the invention, relying on tires and wheels for support such as for operating on a track having comparatively flat aspect, such as a bottom flange of an I-beam type of track; 
         FIG. 15  is a perspective view of a frame of the trolley of  FIG. 14 ; 
         FIG. 16  is a perspective view of an alternative embodiment of a trolley in accordance with the invention, illustrating an engagement arm for engagement by a lift trolley; 
         FIG. 17  is an end elevation view of one embodiment of a trolley frame in accordance with the invention illustrating the connections system or supporting a harness therebelow; 
         FIG. 18  is a frontal, upper perspective view of one embodiment of a lift trolley showing a swing arm for engaging the engagement arm of a carrier trolley; 
         FIG. 19  is an upper, rear perspective view thereof; 
         FIG. 20  is a top plan view thereof; 
         FIG. 21  is a side elevation view thereof; 
         FIG. 22  is an end elevation view thereof; 
         FIG. 23  is a side elevation, cut away view thereof; 
         FIG. 24A  is a perspective view of one embodiment of an adjustable axle for a wheel or roller on a trolley in accordance with the invention; 
         FIG. 24B  is a perspective, exploded view thereof; 
         FIG. 25  is a side elevation view thereof; 
         FIG. 26  is  FIG. 25  is a side elevation view thereof, positioned on, and illustrating a portion of, the frame of a trolley; 
         FIG. 27  is a perspective view of one embodiment of a trolley in accordance with the invention having certain structures, such as cosmetic coverings, guards, and a portion of the braking system removed or visibility of the illustrated components and assembly; 
         FIG. 28  is an underside perspective view thereof; 
         FIG. 29  is an end elevation view thereof; 
         FIG. 30  is a cut away, cross-sectional, side elevation view thereof; 
         FIG. 31A  is an upper, frontal, perspective view of an alternative embodiment of a trolley in accordance with the invention, configured to ride on a triple-tube, truss-type track or a horizontal flange of an I-beam in accordance with the invention; 
         FIG. 31B  is a frontal perspective view thereof from a slightly different angle; 
         FIG. 32  is a top plan view thereof; 
         FIG. 33  is a side elevation view thereof; 
         FIG. 34  is an end elevation view thereof; 
         FIG. 35  is a perspective view of a trolley passing through an electromagnetic braking system fixed to the rail (a segment of which is shown) on which the trolley is traveling; 
         FIG. 36  is a chart illustrating a method for calculating control for adjustment and number of holes in a tab for an adjustable, eccentric axle on a trolley wheel, and control for the spacing of panel and hole tabs; and 
         FIG. 37  is a system of equations defining eddy current braking in a system in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     It will be readily understood that the components of the present invention, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, but is merely representative of various embodiments of structures implementing aspects of the invention. The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. 
     Referring to  FIG. 1 , as well as  FIGS. 2 through 4  specifically, and  FIGS. 1 through 37  generally, a system  10  in accordance with the invention may include a track  12  defining longitudinal  13   a,  lateral  13   b,  and transverse  13   c  directions. Cables  14  ( FIG. 7 ) may be suspended from beams  16  thereabove to support each track  12  location from multiple angles. Accordingly, the vector forces on the track  12  at any location should be resolved by the horizontal forces all being neutralized by one another, leaving only a vertical support vector on the track  12 . 
     Nevertheless, in the presence of a rider turning a corner laterally (horizontally) restrained by the track  12 , the cables  14  in such an event have sufficient tension that they will overwhelm the force of the rider or the momentum of the rider. That force will be substantially less than the lateral preload on the cables  14  in order to neutralize horizontal forces or horizontal force factors with respect to the track  12 . A track  12  may also connect rigidly to the beams  16 . 
     Beams  16  are supported by pillars  18 . Both may be formed of I-beam material. The beams  16  may be considered stringers  16  or rafters  16 . The pillars  18  may be considered support posts  18 , or the like. Typically, the pillars  18  are anchored or fastened to a supporting surface  20 . The pillars  18  may actually have footings therebelow. The supporting surface  20  may support the pillars  18  directly, or the pillars  18  may actually be supported by footings under the supporting surface  20 . 
     The system  10  includes a loading area  22  or deck  22  accessible to users who may load into harnesses or seats in order to travel along the track  12 . A lift system  24  may include mechanisms to travel along a ramp  26  or incline  26  portion of a track  12 . A lift track  28  may parallel the ramp  26  or incline portion  26  of the track  12 . Thus, a lift track  28  may carry a lift trolley  32  or simply a lift chair. The lift track  28  may be of the same material and configuration as a carrier track  12  that actually carries the trolley  30  or cart  30  traveling along the track  12 . Nevertheless, there is no requirement that the lift track  28  operate in the same manner. It simply is a very straightforward and self-managing system if the lift track  20  parallels the track  12  along the ramp  26  or incline portion  26 . 
     In typical embodiments, the trolley  30  or cart  30  travels on wheels beside a lift trolley  32  operating along the lift track  28 . At some point, the lift track  28  may diverge from the carrier track  12  in order to disengage the lift trolley  32  from the trolley  30  or cart  30  carrying a rider. 
     Referring to  FIGS. 2 through 4 , in alternative embodiments, stringers  16  or beams  16  may be the trusses  16  or beams  16  overhead in a building structure. In  FIG. 2 , beams  16  suspend the track  12  therebelow. Pillars  18  need only be the same posts  18  engineered to support the track  12  and the structure of the building. The supporting surface will typically be a floor  20 , but will usually involve footings therebelow engineered to support building, beam  16 , pillar  18 , and track  12  structures. 
     Referring to  FIG. 3 , a path of a track  12  supported by a system of beams  16  on pillars  18  may take any configuration. For the simplicity of the drawings for this application, the illustration of multiple layers, multiple rises as well as corresponding declines in the elevation of the rail  12  as a rider passes longitudinally  13   a  therealong, have been removed. The drawings are sufficiently complex without trying to illustrate multiple layers. Likewise, not illustrated is the “roller coaster” effect of repeating rises and declines in which a trolley  30  would slow with increasing elevation and accelerate with decreasing elevation. 
     In the illustrated embodiment, both the track  12  and the beam  16  are shown as I-beam type construction. In each case, the rail  12  and beam  16  include a bottom flange  17   a,  a web standing in a vertical plane, and a top flange  17   c.  Both flanges  17   a,    17   c  are nominally horizontal or extend in a nominally horizontal plane. 
     Of course, as the rail  12  may course longitudinally  13   a  along a chosen path, it may turn in a lateral direction  13   b  (left or right  13   b ). Likewise, the track  12  may be a strict coaster always tending to decline in a transverse direction  13   c.  Alternatively, the rail  12  may actually operate as a roller coaster that periodically inclines upward  13   c  and declines downward  13   c  to alternately decelerate and accelerate a trolley  30  operating thereon. 
     Multiple beams  16  or stringers  16  may move in different directions, and need not all be parallel to one another. Moreover, the stringers  16  or beams  16  may also operate at multiple layers. Thus, a track  12  may move in a serpentine course about various pillars  18 , and may descend to suspend from lower beams  16 , while originally suspending from upper beams  16 . 
     Referring to  FIG. 4 , an eddy current braking system  29  (ECBS  29 ) may be set up to operate at a loading location  22 . Necessarily, speed and stopping must be controlled in order to unload and load riders on trolleys  30 . In the illustrated embodiment, a controlling ECBS  29  is also shown at a remote location away from a loading platform  22 . For example, following a rapid decline, and just proceeding a comparatively sharp curve, an ECBS  29  may be applied to a trolley  30  in order to reduce the amount of lateral  13   b  swinging or rollout (roll) by a rider suspended in a harness system  31  under a trolley  30 . 
     Referring to  FIGS. 4 and 5A through 5C , an alternative embodiment of a course is illustrated with trolleys  30  and a lift trolley  32 . In this embodiment, the structures constituting the beams  16  on their pillars  18  are comparatively regular in that they form a rectangular arrangement, perpendicular beams  16  are supported by an array of pillars  18 , yet the course of the track  12  is not constrained to that distribution for its shape. Meanwhile, in all embodiments, the lengths and loads on cables  14 , beams  16 , and pillars  18  may be engineered to provide continuous descent, or an up-and-down  13   c,  undulating path similar to a conventional roller coaster. Momentum will carry uphill and decrease, then recover when passing downhill, over an undulating path. 
     Referring to  FIGS. 5A through 12A and 12B , while continuing to refer generally to  FIGS. 1 through 37 , a Figure number absent trailing letters indicates all Figures having that leading numeral.  FIGS. 5A-5C  illustrate a short portion of overall tracks  12 ,  28 .  FIGS. 6A through 9  illustrate a “static universal” system for solidly supporting a rail in an I-beam configuration.  FIGS. 12A and 12B  illustrate cable assemblies  40  for suspending a track  12  or rail system  12  by vectors (cables  14 ) of support. 
     Referring to  FIGS. 5A-5C , a rail  12  may rely on a system of simple brackets  34  for support. These brackets  34  may also connect together the main trolley rail  12  and the lift trolley rail  28 . If cable assemblies  40  support the rail  12 , these may still be adequate. 
     Referring to  FIGS. 6A through 11 , while continuing to refer generally to  FIGS. 1 through 37 , a system of plates  33  may be assembled to fit with the mounts  36  in order to suspend a rail  12  below the beam  16  in a system  10  in accordance with the invention. For example, a plate  33   a  may be juxtaposed to a plate  33   b  interconnected with and by intermediate vertical plates  33   c  and  33   d.    
     Referring to  FIG. 6A , an assembled unit  38  operates as a core  38 , also referred to as a “static universal”  38 . By providing several degrees of freedom and substantial adjustability in order to find a fit and make a fit, the static universal  38  differs from a conventional “universal joint unit.” A universal joint rotates in operation. The purpose of the universal joint is to provide alignment between two shafts that are very difficult to align, and may not be aligned or even parallel. A conventional rotating universal joint should never stand alone. Rather, universal joints are used in pairs. Each universal joint is connected at an outer (outboard) end to a shaft. One of those universal joints must be able to slide along their mutually interconnecting shaft. It is typically provided with a spline for that purpose. Meanwhile, the two universal joints connect at their inner (inboard) end of each to that connecting shaft. Usually, this connecting shaft is the location where the slide (e.g., spline) is positioned. 
     In contrast, the static universal  38  is designed to ease alignment between a rail  12  suspended below a supporting beam  16  and then rigidly fix that fit. 
     Before explaining the operation of the universal  38 , the construction thereof should be understood. In general, a plate  33   a  is connected to a plate  33   b  by two plates totally orthogonal  33   c,    33   d.  Each individual plate  33   c,    33   d  is provided with tabs fit into slots  39   c  in plate  33   a  and slots  39   d  in plate  33   b.  In fact, tabs of each of the plates  33   c,    33   d  are received into each of both plates  33   a  and  33   b.    
     Moreover, the two plates  33   c,    33   d  are also slotted with slots  39   e,    39   f  in order that they themselves may be slotted together. In this way, the static center  38  is a stack of plates  33   a  horizontally welded to plates  33   c,    33   d,  to which is welded the juxtaposed plate  33   b.  A suitable length of welding bead may be applied at the intersection of any two of the plates  33   a,    33   b,    33   c,    33   d.    
     Referring to  FIGS. 7, 8, and 9 , the various views, typically a bottom plan, end elevation, and side elevation view, respectively, illustrate the orientations and locations of various slots  39   a,    39   b.  These are provided for attaching the static universal  38  to a mount  36   a  on a beam  16 , and a mount  36   b  on a rail  12  to be suspended below the beam  16 . 
     The mounts  36   a,    36   b  may essentially look much like the plates  33   a,    33   b.  However, the slots  39   a  in the plate  33   a  may typically be oriented to extend at right angles to the corresponding slots  39   a  in the mount  36   a.  Meanwhile, the mounts  36  may each appear to be or to be constituted by three out of the four plates  33   a,    33   b,    33   c,    33   d  illustrated for the static universal  38 . Accordingly, a mount  36  may look very much like the static universal  38  absent one non-matching plate. In place of that plate will be welded the beam  16 , or the rail  12 . Alternatively a clevis (or several) and cables  14  may connect to a plate  33   c,    33   d.    
     Referring to  FIGS. 10 and 11 , two common alignment issues are demonstrated by a curved portion of a rail  12  suspended below a beam  16 , and a straight portion of a rail  12  passing diagonally under a beam  16 . In the illustrated embodiments, one can see that apertures  39   a  in the plates  36   a,    36   b,  are connected by bolts to the plates  33   a,    33   b  through the apertures  39   a  in that corresponding plate  33   a,    33   b.  By positioning the slots  39   a  in the carrier plate  36   a  or mount  36   a  and providing sufficient length of those slots  39   a,  a wide window of opportunity and tolerance exists to receive a bolt wherever the two slots  39   a  from the plates  33   a,    36   a  cross one another. Thus, initial close fits and tight tolerances are avoided. 
     Similarly, if adjustments need to be made, the position of bolts in the slots  39   a  may be shifted by simply moving the plate  33   a  with respect to the plate  36   a  before the bolts are tightened. 
     Meanwhile, the slots  39   b  in the plates  33   b,    36   b  may be rotated through a wide angle to coincide. It has been found that angles on the order of 60 degrees are completely tractable, and provide a virtual assurance of overlap between the slots  39   b  in the respective plates  33   b,    36   b.  Accordingly, the rail  12  may be assembled loosely to the beam  16 , by securing bolts through the slots  39   b.    
     Then, adjusting the position of the plate  33   a  with respect to the plate  36   a  will fit the static universal  38  in translation (linear motion; an engineering and mechanics term of art, as opposed to rotation). In other words, the slots  39   b  in the plates  33   b,    36   b  provide for a rotational degree of freedom to achieve alignment,. The slots  39   a  in the plates  33   a,    36   a  provide for translation in two dimensions (degrees of freedom). 
     Three degrees of freedom, two in translation and one in rotation, are provided for securing alignment. The vertical degree of freedom in translation and the rotational degrees of freedom about a vertical  13   ac  axis are available by a fastener (e.g., bolt). Vertical translation is needed to secure the rail  112  and universal  38  to the beam  16 . 
     In other words, securing the static universal  38  to the mount  36   a  is intended to rely on, then lock in and remove, the degree of freedom in a vertical direction  13   c.  Similarly, securement of the static universal  38  to the mount  36   b  of the rail  12  is intended to cinch the juxtaposed plates  33   b,    36   b  together, thus removing any ability to move in a vertical direction  13   c.    
     It is certain that adjustment in the vertical direction  13   c  is available, simply by choosing the length of bolts to connect the mounts  36   a,    36   b  to the static universal  38 . Thus, one may look at that connection scheme as permitting a third degree of freedom of adjustment, but differs. That is, the degree of freedom in the vertical  13   c  or transverse  13   c  direction is intended to apply force, not relieve it. It is intended to move components together, not align them freely prior to securement together as with the slots  39  between the mounts  36  and the static universal  38 . 
     Thus, in general, beams  16  and rails  12  may be built according to manufacturing drawings with liberal tolerances. At some point, the mounts  36   a,    36   b  will be secured thereto according to the drawings. This may be done onsite or in a factory. By use of the static universal  38 , three degrees of translation and a degree of rotation may all be provided to secure alignment and attachment of the mounts  36   a,    36   b.    
     In general, I-beam material is a useful structural material. The principle of construction and engineering discussed as “section modulus” refers to the cross-sectional area of material, and where that cross-sectional area is in the net cross section of the envelope (outside perimeter) of a structural element such as a beam  16  or a rail  12 . Section modulus relates to the integral of a distance squared from the center (neutral axis, a central location at which no bending stress exists) in a member having compression at one extreme outer fiber and tension at the opposite extreme outer fiber. 
     A solid material, for example, may have a circular cross section, rectangular cross section, or another. Such a member is heavier than it needs to be to provide its function in most cases. Rather, so long as a flange  17   a  is left at the outermost extremum of dimension across a beam  16 , or a rail  12 , and another flange  17   c  is provided at an opposite extremum, only a web  17   b  of material need connect them to space them apart, protect against buckling, and so forth. Thus, the I-beam is a useful structure with an efficient strength-to-weight ratio, characteristic for static support. 
     In a system  10  in accordance with the invention, it has been found that rails  12  may be fabricated to curve in a lateral direction  13   b  (side to side  13   b ) or in a transverse direction  13   c  (up and down, vertically  13   c ) in order to provide acceleration, deceleration, and turning. However, it has been found that construction may be simplified by limiting curvature of a rail  12  to a single direction  13  at a specific location. Thus, there is no need to compound a transverse  13   c  incline or decline with a lateral  13   b  turn. Instead, throughout any longitudinal  13   a  expanse, a rail  12  may be proceed straight, through a turn in a lateral direction  13   b  or through a rise or fall in a transverse (vertical) direction  13   c.    
     In certain embodiments, the track  12  may be joined in segments welded together or bolted together based on associated flanges extending from one segment and connecting to flanges of another. Thus, track  12  may be bolted together one joint at a time for assembly and shipping. In certain embodiments, the connection of the track  12  to the frame structure  15  or framing system  15  may be by means of cables  14 , static universal  38 , or by direct connection. In certain embodiments, ball joints may be used between a beam  16  and a track  12  in order to provide support vertically, restraint in a longitudinal  13   a,  lateral  13   b,  and transverse (vertical) direction  13   c  while still permitting some degree of freedom in rotation. 
     Likewise, each segment or section of a track  12  may have mounting apertures drilled in it in order to accept connections to various brackets such as those required to connect to the lift system  24 , and ECBS system  29 , stops or brackets for an anti-roll-back arm  92 , various sensors such as optical or proximity sensors which may operate on a radio frequency, light, or other physical sensibility. Meanwhile, other systems such as motors and drives may also be connected by brackets for which mounting apertures may be provided in a section of track rail  12 . 
     In certain embodiments, the track  12  may be shaped different  14  in different areas. For example, an I-beam structure inside a building may be suitable since standard lengths may be appropriate inside buildings. For longer spans, a track system  12  such as a truss track  60 , sometimes called a space track  60  may be used. These are effectively trusses  60  with larger section modulus for their weight and can span greater distances without as many intermediate supports required. 
     I-beams tend to be comparatively heavier for their strength than a truss track  60 . Accordingly, a longer or taller dimension across a truss track assembly  60  may provide improved strength-to-weight ratio and simplify assembly. On an I-beam track  12 , a rider may still have the thrill of the rolling motion represented by swinging in a lateral direction  13   b  (a roll motion in aircraft parlance) on turns. This is discussed in more detail elsewhere herewithin. 
     Referring to  FIGS. 6A through 9 , another type of bracket  38  may be thought of as a static universal  38 . Mounts  36  are secured to carrier tracks  12 , while other mounts  36  secure to the beams  16 , typically by welding in each case. The adjustable bracket  38  then secures the mounts  36  together, a top mount  36   a  on the beam  16  and a bottom mount  36   b  secured to the carrier track  12 . Here again, a reference numeral having a trailing letter refers to a specific instance of the item or type designated by the reference numeral. Thus the numeral alone refers to the item or type, while the number with a trailing letter points out a particular instance thereof. 
     Meanwhile, an adjustable bracket  38  or static universal bracket  38  is designed to bolt to, and slide with respect to the adjustable mounts  36 . Adjustable mounts  36   a  have slots  37  configured as straight slots  37   a.  Similarly, the top of each static universal will have straight slots  37   a  oriented to extend at right angles to the slots  37   a  in the mount  36   a.  Thus, the brackets  38  may translate with respect to the mounts  36   a  due to the crossing of slots  37   a.    
     Arcuate slots  37   b  are in mounts  36   b  and at the bottom plate  33   b  of the universal  38 . Thus, the universal bracket  38  may rotate to align with respect to the mounts  36   b  by a full (but interrupted) circle. The result is to virtually neutralize the discrepancies in dimensions and the resulting force operating to misalign the mounts  36   a,    36   b,  and the static universal brackets  38 . Alternatively, one may regard the mounts  36  and bracket  38  together as the “static universal”  38 . 
     In this way, no couple occurs. The term “couple” is an engineering and construction term of art indicating a net force tending to rotate (produce torque). Typically, two forces are positioned as equal and opposite, parallel, but not co-linear, such that that they tend to rotate a body. A couple need not exist within the bracket  38  where it could cause misalignment during assembly or construction, distort the loading and possibly deflect the track  12  in operation. 
     One will note, that an adjustable bracket  38  may be designed in multiple pieces that may be fitted and welded together to form a system of apertures  37 . The apertures  37   a  on one face are straight slots  37   a.  Slots  37   b  are elongated about a circumference or circumferential direction, at some radius matched to a similar radius upon the mount  36   b.  Straight slots  37   a  in the mount  36   a  and bracket  38  slots  39   b  are orthogonal. 
     Accordingly, the adjustable bracket  38  may be rotated with respect to the adjustable mount  36   b,  in order to align simply and easily. Slots  37   a  virtually always align across slots  39   a,  because they cross orthogonally and are elongated to several “width” values in length (e.g., ½ inch×2 inches, 1.3×6 mm). They bolt together on a plane in a nominally horizontal direction and neutralize the force vectors therein. 
     Meanwhile, other weldments or fasteners may exist in order to secure the lift track  28  in fixed, rigid-body, relation to the carrier track  12 . At some point, an end of the lift track  28  may include a chain return in or about which a chain may roll on a sprocket to operate in a continuous manner along the carrier rail  28 . Typically, the end (terminal end or distal end) of the lift track  28  may diverge up, down, or horizontally away from the carrier track  12 , in order to disengage a lift trolley  32  from a carrier trolley  30  or passenger trolley  30 . 
     Referring to  FIGS. 5A and 5B  as well as  FIGS. 12A and 12B , while continuing to refer generally to  FIGS. 1 through 37 , a cable system  40  or cable assembly  40  may include thimbles  42  about which cables  14  are wrapped in order to be gripped by a clamp  44 , seal  44 , lug  44 , or the like. In other words, a lug  44  may be deflected inelastically (plastically) in engineering terms. This means it has been yielded mechanically to permanently distort, and not elastically return to its previous shape. A lug  44  may secure the cable  14  to itself at the very end thereof to wrap around a thimble  42  protecting the individual strands against abrasion in the cable  14 . 
     A turnbuckle  46  may connect to an eye  47  for securing to a thimble  42  in the cable  14 . Meanwhile, at an opposite end of the turnbuckle  46 , a clevis  48  may secure to a plate or one of the apertures in a plate of the brackets  34   a  or directly to an adjustable bracket  38  supporting a track  12 ,  28 . Meanwhile, at the opposite end thereof, another clevis  50  may connect to a supporting member  16 , 18 . A bracket  34  or eye may secure to one of the beams  16  or pillars  18 . 
     Typically, a bolt  56  may secure a clevis  50  at the anchor end of the cable assembly  40 . Meanwhile, a pin  52  such as a smooth pin having a head on one end and a keeper  54  such as a cotter pin on the other end may secure the clevis  48  to a bracket  38  or other mechanism or device for connecting to a track  12 . 
     Referring to  FIG. 13 , a truss track  60  is one embodiment of a track  12  useful in accordance with the invention. The truss  60  may include a top tube  62  or suspense tube  62  that will be bracketed by a beak (e.g., two-piece, axially-divided cylinder; or upper and lower plates capturing another therebetween) a tab, an eye, or other bracketing system in order to secure the overall truss  60  to the cables  14  by cable assemblies  40 . Any or all of the system described herein for connecting to cables  14  may be used on this type of a truss assembly  60  for a track  12 . In a manner of speaking, the lower tubes  64  or bottom tubes  64  operate as the actual track  12  in contact with wheels  70 . 
     Meanwhile, frames  66  or spacers  66  may provide structural strength, stiffness, and alignment of the top tubes  62  and bottom tubes  64  with respect to one another. Accordingly, the tubes  62 ,  64  may be curved, bent, or the like in order to accommodate any overall shape of the longitudinal  13   a  path of the cross section thereof. In this way, the cross section and the relative spacing of the tubes  62 ,  64  with respect to one another remain the same throughout. However, the frames  66  maintain that relative position, and the rigid-body connection therebetween. 
     The path of a line (e.g., curve) down some central axis or centroid (an engineering term of art used here as commonly known in the engineering art) of the area of the truss  60  travels along a path that ultimately becomes the axial  13   a  or the longitudinal  13   a  path along a longitudinal axis  13   a  of the truss  60 . The bottom tubes  64  form a track  12  operating, typically spaced therebelow, along that path. 
     Struts  68  may be fastened mechanically by bolts, rivets, brackets, or other fasteners, welding, or other mechanism in order to space apart and stiffen the tubes  62 ,  64  with respect to one another. Meanwhile, a trolley  30  operates along the bottom tubes  64  as a track  12  supporting that trolley  30 . 
     The bottom flange  17   a  of an I-beam having a vertical web  17   b  also may serve as a track  12 . In such an embodiment, the rail  12  may be heated and formed to decline, incline, turn right, turn left, or twist. Twisting is not preferred. Permitting a rider to swing (roll) outside a turn in response to centripetal force adds a “roll” element to the ride. There is no need to twist the rail. A series of bends, in one degree of freedom at a time, permit downhill, uphill, left, right, and roll reactions. Roll, yaw, and pitch are used here in the same sense as in aircraft and engineering generally as rotations or pivoting about a longitudinal  13   a  axis, transverse  13   c  axis, and lateral  13   b  axis, respectively. 
     Referring to  FIGS. 14 and 15 , while continuing to refer generally to  FIGS. 1 through 37 , in an alternative embodiment of a trolley  30 , rollers  70  or wheels  70  may operate as carriers  70   a,  idlers  70   b,  and guides  70   c.  In the illustrated embodiment, the carriers  70   a  include not only a tire  71   a  but an inner wheel  71   b.  The rollers  70  typically operate on axles  72 . 
     Herein, a designation of a reference number indicates a component and a component type. A reference numeral followed by a trailing alphabetical character indicates a specific instance of the item or type designated by the reference numeral. 
     Accordingly, it is proper herein to speak of all the rollers  70  or any rollers  70 , and specific types or positions of rollers  70  as carriers  70   a,  idlers  70   b,  and guides  70   c.  The difference therein is that carriers  70   a  typically carry the principal load of the weight of the trolley  30  and the weight of the equipment and a rider therebelow. Meanwhile, idlers  70   b  typically oppose the carriers  70   a,  but only apply force when required to downwardly restrain the trolley  30  and maintain its position along the track  12 . 
     Typically, guides  70   c  operate for horizontal stability, like the idlers  70   b  act for vertical stability, to maintain lateral position or stability of the trolley  30 . In the event that a rider passes through a turn along the track  12 , there will be a momentum component as centripetal forces must make that turn and pull the rider along the curvature of the track  12 . The guides  70   c  may contact the track  12  in order to provide supporting lateral forces. 
     Each of the rollers  70  rotates around an axle  72 . Accordingly, the axle  72   a,    72   b,    72   c  correspond, respectively, to the rollers  70   a,    70   b,    70   c.    
     A frame  74  may support all of the rollers  70  by various brackets  76 . Likewise, the frame  70  may ultimately be covered with covers  78  that act to provide cosmetic appearance as well as to guard against fingers of an operator or rider being placed at pinch points or other dangerous positions with respect to the wheels  70  or rollers  70  of a trolley  30 . 
     Magnets  80  are aligned along a plate  82  or bracket  82  secured to support the array of magnets  80 . The magnets  80  may extend as an array in various directions. For example, the longitudinal direction  13   a  is a direction of travel. A horizontal direction  13   b  is a side-to-side direction. Meanwhile, a vertical direction  13   c  may be thought of as an up-and-down direction. Thus, a vertical descent provides a gravitational force or acceleration moving a trolley  30  along a track  12  in a longitudinal direction  13   a.  Meanwhile, turns may result in forces acting on the trolley  30  to put the guide  70   c  in contact with a track  12 . 
     Referring to  FIGS. 14 through 34 , while continuing to refer generally to  FIGS. 1 through 37 , each of the trolleys  30  may include an engagement arm  84 . For example, in  FIG. 15 , the trolley  30  of  FIG. 14  has been stripped down to its frame  74 . Accordingly, the various brackets  76  may secure to the frame  74 , holding axles  72  for the various rollers  70 . 
     Meanwhile, the engagement arm  84  extends laterally outward away from the track  12  and the trolley  30  in order to engage the lift trolley  32 . The engagement arm  84  may actually extend horizontally in both directions, as illustrated in  FIG. 16 . Meanwhile, the rollers  70   a  need not have rubber tires. They may simply be steel rollers  70 . Nevertheless, the structure of wheels  70  will depend upon various engineering factors and comfort factors for a rider. 
     Referring to  FIG. 17 , while continuing to refer to  FIGS. 14 through 34  and  FIGS. 1 through 37  generally, an axial view or longitudinal end elevation view of one embodiment of a frame  74  of a trolley  30  illustrates an engagement arm  90  extending horizontally or laterally away from a central or vertical plane of symmetry  85  of the frame  74 . One will see that an eye bolt  86  secures a connector  88  or link  88  that may then connect to a harness of a user. 
     Referring to  FIGS. 18 through 23 , while continuing to refer to  FIGS. 14 through 34 , and  FIGS. 1 through 37  generally, a carrier trolley  32  may operate similarly to the carrier trolley  30  but on the lift track  28 . Accordingly, a system of wheels  70  on brackets  76  connected to a frame  74  may operate similarly. However, a swing arm  92  is pivoted about an axle  93 , such as a bolt  93  secured to the frame  74 . 
     The lift trolley  32  may be a design to match a carrier trolley  30  in which a swing arm  92  engages a bar on a chain link. The swing arm  92  is free to move away from a backing element  94  or stop  94  that prevents motion in a reverse (whether that be forward or backward) in longitudinal direction  11  a. The swing arm  92  may only swing in one direction, (e.g., forward). Thus, as an engagement arm  84  or a chain link protrusion may pass forward toward the end  95   a  of the trolley  32 , the swing arm  92  is engaged by the engagement arm  84 , or chain link bar or tab, thus pivoting about the axle  93 , and permitting the engagement arm  84  and trolley  30  (or chain link bar) to pass. Upon passing by the trolley  30  and the engagement arm  84 , the swing arm  92  now pivots toward the opposite end  95   b  of the lift trolley  32 , stopping at the stop  94  from further movement rearward. The stop  94  stabilizes the swing arm  92 , thus allowing it to push against the engagement arm  84  with the force necessary to lift the trolley  30  and its rider up along the ramp portion  26  of the track  12 . If the trolley  32  is acting as a carrier trolley it moves forward, the swing arm  92  lifts, the extension from a chain link engages it, and the trolley  30 ,  32  rises up the ramp. The swing arm  92  also acts as a ratchet against support stops along the track. A loss of power does not allow a cart  30  to retreat backward or downward. 
     Referring to  FIGS. 20 through 23 , while continuing to refer to  FIGS. 14 through 34  specifically, and  FIGS. 1 through 37  generally, other views of the lift trolley  32  illustrate the various components, and in particular, the wheels  70  operating on their axles  72 , secured by or with brackets  76  to the frame  74 . 
     Referring to  FIGS. 24A through 26 , a trolley wheel  70  may be mounted on an axle  72  that is itself eccentrically mounted by a tab  76  or bracket  76  to the frame  74  of a trolley  30 . For example, in the illustrated embodiment, the axle  96  secures to the bracket  76 , and may actually pass through the bracket  76 , allowing the bracket  76  to rotate with the eccentric axle  72 . 
     Referring to  FIG. 26  specifically, relative to  FIGS. 24A, 24B, 25, and 30 , adjustment of a wheel  70  and the clearance of that wheel  70  with respect to the rail  12  on which it rides may be done with a great degree of precision yet flexibility. By arranging a series of apertures  99  in the bracket  76  or tab  76 , and another set of apertures  101  in the frame provides several incremental points of coincidence therebetween. A single fastener (e.g., pin, bolt, etc.) can be positioned to fix rotation, thus selecting a clearance. 
     The apertures  101  in the frame  74  of a trolley  30  are spaced apart from one another on an arc, a semicircle. That semicircle or arc is centered around the center point  103  or center line  103  passing through the axle  96 . One will note that the apertures  99  and the tab  76 , the apertures  101  in the frame  74 , and the axle  72  about which the wheel  70  rotates all have the same center  103  of rotation. Thus, the axle  96  or fastener  96  about which the axle  72 , the wheel  70 , and the tab  76  pivot or rotate are all coincident, collinear, and so forth. 
     Meanwhile, the apertures  99  and the tab  76  in the apertures  101  in the frame  74  all center about the arc on which they are distributed. Each centers about that center line  103  or center point of the axle  96 . Many alignment options are possible. Note that a movement (pivoting) of the tab  76  about the center line  103  moves the apertures  99  with respect to the apertures  101 . The apertures  99  are separated by an angle  105   a  while the apertures  101  are separated by an angle  105   b.  Each incremental movement or pivoting of the tab  76  about the center line  103  rotates the eccentric axle  72  by some incremental angle  105   c.  This is required to obtain the next available alignment between an aperture  99  and an aperture  101 . One will note that a bolt, pin, or some other fastener may be inserted, preventing further relative pivoting or rotation of the tab  76  with respect to the frame  74 . A fastener may be passed through a pair of coincident apertures  99 ,  101  upon alignment therebetween. By having some number (three in the illustration) of apertures  99  in the tab  76 , and some other larger number over some larger arcuate angle of the distributing of apertures  101 , an interesting phenomenon occurs. The next available incremental angle  105   c  is simply the angular distance or arc length between the next available alignment of an aperture  99  in the tab  76 , and the next available aperture  101  in the frame  74 . An Analysis of how these angles  105   a,    105   b,    105   c  are determined, will illustrate how adjustments may be made on a Vernier basis. That is, the next available incremental arc  105   c  need not be the one used. Rather, one may adjust the tab  76  to the nearest, desired, suitable, available setting. In this way, the tab  76  may be set at any one of the available matches between apertures  99  and apertures  101 . 
     A single bolt or other fasteners all that is required in the paired apertures  99 ,  101  aligned at that position. Accordingly, the discrete distribution of the apertures  99 , and their relative angular displacement  105   a,  and a similar distribution of the apertures  101  at a different angular distribution  105   b  provides numerous, precise, discrete adjustment locations. 
     The significance or purpose of the adjustability between the tab  76  and the frame  74  is to provide slight motion or rotation (pivoting) by the eccentric axle  72  about its axle  96 . As the eccentric axle  72  pivots around the fixed axle  96 , the centroid  107  or center  107  of area of the axle  72  moves. In short, the centroid  107  or center  107  of the circle  72  that is the axle  72 , pivots about the center line  103  of the axle  96 . 
     Thus, as the tab  76  rotates about the center line  103 , the center  107  of the eccentric axle  72  moves up or down with respect to the frame  74 . In this way, the wheel  70  is closer or farther from the rail  12  (if the wheel  70  is in idler  70 ). On the contrary, if the wheel  70  being adjusted by the tab  76  is a carrier  70   a,  then it is the frame  74  that is lifted or dropped relative to the rail  12  on which the wheel  70  runs. 
     Typically, it is only necessary to have adjustability for the idlers  70   b  operating underneath the rail  12  as keepers, to prevent the trolley  30  from jumping off the rail  12 . On the other hand, it is also much simpler to have a single set of wheels  70  that are adjustable, and not the carrier wheels  70   a.    
     Referring to  FIGS. 24 through 26 , while continuing to refer generally to  FIGS. 1 through 37 , an adjustability may be built into the brackets  76  supporting various wheels  70 . This is most valuable for idlers  70   b  and guides  70   c.  For example, an axle  72  may actually be an eccentric  72  fastened by a pivot  96  or secondary axle  96  about which the axle  72  may be temporarily rotated eccentrically. 
     The axle  96  is not centered about a central axis  95  or axis of rotation  95  of the wheel  70 . Rather, the axle  72  itself has its own axles  96 , with a new center of rotation, eccentric with respect to the rotation of the wheel  70  itself. One may rotate the axle  72  and bracket  76  together about the internal axle  96 . One may fix that position of the tab  76  or bracket  76  with respect to the frame  74  mounting the axle  96  by threading a set screw  98  from and through the axle  96  to which it is fixed, against the frame  74 . This fixes the particular alignment and positioning of the wheel  70  with respect to the track  12 . Thus, clearances with respect to the track  12  and the various wheels  70 , may be maintained for smooth travel, minimum noise, and safety by this mechanism. 
     Various apertures  99  may be provided in the bracket  76  in order to secure to the frame  74 . Any or all of the wheels  70  may be subject to a mount system in accordance herewith. 
     In the illustrated embodiment, a shim  97  may reduce friction between the bracket  76  and the wheel  70  rotating about the axle  72 . The wheel  70  may have a bearing incorporated as part of the axle  72 , as part of the wheel  70 , or positioned therebetween. Thus, rotating friction may be handled by a bushing, bearing, journal, lubricant, combination, or the like. The face of the bracket  76  or surface against which the wheels  70  rides, will not see significant force. Nevertheless, a shim  97  or washer  97  may provide standoff distance of the wheel  70  from the brackets  76 , while also reducing friction therebetween. 
     Referring to  FIGS. 28 through 34  particularly, as well as  FIGS. 1 through 37  generally, various embodiments of a trolley  30  may include below a frame  74  of the trolley  30  an axle  102  connected in rigid-body relation to a yoke  100 . The yoke  100  may be an assembly  100  in which spacers  104  extend between end plates  106 . The end plates  106  may be in a triangular shape in which, at one upper vertex, eye blocks  108  or eye bearings  108  provide a pivotable connection to the axle  102 . The axle  102  may typically rotate with respect to the eye blocks  108  or eye bearings  108  in order to pivot laterally the harness (seat)  120  suspended under the yoke assembly  100 . Thus, the end plates  106 , although longitudinally spaced from one another by the spacers  104 , may act in rigid body motion. 
     A damper  110  may connect between the frame  74  and the yoke assembly  100  in order to dampen the relative motion between the frame  74  and the yoke assembly  100 . The damper  110  may operate as a dashpot, as that term is recognized in mechanics, machinery, or engineering parlance. A dashpot is typically a container (e.g., cylinder) of viscous liquid contained in a vessel through which a perforated plunger is driven by an actuator rod. Alternatively, a piston may move liquid through any restricted path (even going outside the container) between opposite faces of the piston. Sometimes a surface may simply pass through an open body of viscous liquid. 
     The friction drag of the liquid passing through small apertures provides damping proportional to the square of velocity of that liquid passing through. Thus, lateral  13   b  motion of a rider in a harness  31  is dampened by a damper  110  modulating or moderating the resistance to relative movement of the yoke assembly  100  with respect to the frame  74  of the trolley  30  traveling along a track  12 . Resistance may be tuned (adjusted) to control the number of oscillations permitted back and forth. 
     In operation, a framing system  15  may support itself and a track  12 . A suspended track  20  allows trolleys  30  with seats  120  to travel along below the track  12 . A framing system  15  may allow a variety of trolleys  30  and seats  120 , including soft, flexible seats or hard seats, harnesses, fabric seats, or enclosures on carts. A system  10  may include a control or damper. This may be tuned to permit swaying by a rider on turns. Thus, a user may experience three degrees of freedom of motion in translation and once of rotation at once while in the seat, although the rail and the framing system need not progress in more than two directions at one time. “Roll” may be controlled by tuning the damping of a trolley  30 . 
     A rider or user may be suspended from a cart  30  following the rail  12 . A rider seat  120  and straps  122  may pivot with the yoke  100  around an axle  102 . The damper  110  may adjust to damp optimally (critical damping) limiting that swaying to a single cycle or half cycle. This prevents a rider from contacting structures  15  or another rider. On the other hand it provides a third degree of freedom of motion (rotation, swinging laterally) enhancing the sped and momentum. 
     The path of the rail  12  need not rotate. It may turn without dropping and drop without turning. Also, there may be limited (e.g., six inch) drop along a specified straightaway, which may be near a landing zone or finishing area. If the rail  12  were curved laterally  13   b  with a comparatively heavy rider, such a rider may be swinging heavily. Therefore, the damper  110  may be adjusted (tuned). Tuning a damper is taught in any instruction manual for the ordinary mechanic who installs or adjusts pendulous masses. The theory and equations are available in any text on mechanics dynamics. 
     For example, using a 250 pound weight, one may tune the damper  110  to achieve lateral  13   b  sway damped to an acceptable level, typically no more than a single cycle of motion. It is acceptable, even desirable, to leave some sway in the ride, to heighten excitement and provide a natural dynamic motion on turns. 
     The damping system  110  may use hydraulic dampers  110  such as automotive steering systems use to reduce oscillations (shimmy). They are adjusted (tuned it) to critically damp about a 250 pound rider. This adjustment may be calculated analytically, but is easily made experimentally using a weight in a seat  120  because of the pendulum action. 
     The damper  110  may be adjusted and tuned in order to prevent oscillation, reduce any abruptness of motion on turns, or the like. Nevertheless, for most riders, the lateral  13   b  movement of the harness seat  120  below the trolley  30  on corners is a desirable part of the ride. Accordingly, this may be tuned according to the principles of damping of oscillations as taught in any textbook on dynamics and damping systems. 
     A pendulum operates the same regardless of the weight, notwithstanding one may have to ignore air, drag. In the pendulum equation, air drag does actually have an effect. Within the scope of a system  10 , one may limit lateral swing back and forth to not be excessive. A trolley  30  may be tuned for drag but theoretically works for all riders. Timing can be tuned for the track, its decline, and its curves. 
     Typically, the end plates  106  are provided with apertures  112  through which fasteners  121  such as carabiners  121  may connect to straps  122 , slings  122 , or the like supporting a chair  120 , seat  120 , or harness  120  for a user. A chair  120 , harness  120 , gondola  120 , or the like may suspend from slings  122  (fabric web strips  120 ) connected by carabiners  121  or other connectors  121  passed through the apertures  112  of the end plates  106 . 
     The harness system  31 , being suspended below the yoke  100  permits independence of motion of a rider or patron in a lateral direction  13   b,  and moreover in a rotating, “roll” direction. This improves the ride, but made be damped by the damper  110 . A damper  110  may adjust to modify, reduce, or preclude oscillation. It may otherwise tune the rolling motion or lateral  13   b  swinging of the harness system  31  and yoke  100  together. 
     By using the connectors  121  such as carabiners  121  a certain degree of freedom is permitted between the actual harness seat  120  itself and the yokes  100 . Nevertheless, due to the use of four straps  122 , any relative movement of a rider and harness seat  120  with respect to the yokes  100  is unusual, short distanced, and very temporary. In general, relative motion of the yoke  100  with respect to the trolley  30  supporting the yokes  100  is freely permitted under the control of the damper  110  and its resistance setting (resistance to motion). 
     Four points of connection may typically stabilize the chair  120  of a rider to resist rotation about a vertical axis  13   c  (yaw), lateral axis  13   b  (pitch), and longitudinal axis  13   a  (roll) with respect to the yoke  100  itself. Inordinate swinging forward or backward is nearly impossible. As a practical matter, the axle  102  accommodates a desired amount of lateral  13   b  swinging (resulting in a rolling motion) at corners (turns) along the track  12 . The yoke assembly  100  may pivot to accommodate the force vectors acting. The straps  122  fix the seat  120  laterally to the yoke  100 . The damper  110  is tuned to damp out excessive oscillations laterally while still permitting the “rolling” motion of swinging out on turns of the track  12 . 
     It has been found that a seat  120  formed of a fabric, mesh, or the like serves much better than would a solid seat  120 . The freedom of motion and the comfort of the rider more closely approximates a zip line. In fact, in certain embodiments, the damper  110  may be reduced in effect (damping force reduced) in order to provide a more “wild” ride similar to what a zip line would provide. In a more stringently damped configuration, the damper  110  may reduce the trolley  30  motion to more closely approximate that of a rail-based, conventional, roller coaster. 
     Referring to  FIGS. 31A, 31B, and 32 through 34 , as well as  FIGS. 1 through 37  generally, an alternative embodiment of a trolley  30  may be configured to operate on the track  12  represented by either an I-beam or the lower tubes  64  of the truss  60 . In the illustrated embodiment, the frame  74  is constructed of layers of a material, typically a steel of suitable type. This particular embodiment may be manufactured by assembling layers of steel. Layers may be laminated together by bolting or riveting. 
     Fastening between the principal beams  114  and angled struts  116  may be accommodated by making the struts  116  to have ends that fit onto or into a stackable beam  114 . Thus, material integrity is sustained by the continuity of material without fasteners, welds, or the like therebetween. In addition, gussets  117  may be positioned to maintain the angles between the beams  114  and the struts  116 . The struts  116  may actually be plates that have been bent to be a part of the stack up of the beam  114 . For example, plates  118  may actually form the brackets  76  in which the wheels  70  are contained. 
     Again, in this embodiment, the damper  110  is clearly shown. Moreover, the structure of the yoke assembly  100  is a somewhat triangulated connection to the end plates  106  and spacers  104 , to act in rigid body motion. The axle  102  rotating in the eye blocks  108  or eye bearings  108  may pivot with respect to the frame  74 , under the influence of damping by the damper  110  modulating or damping that motion. 
     A standoff  120  may secure rigidly or non rigidly to the frame  74 . The standoff  120  may secure between adjacent trolleys  30 . The standoff  120  simply maintains distance and longitudinal direction between two trolleys  30 . Meanwhile, the actual alignment of the trolleys  30  on the track  12  is provided by the assembly of wheels  70  or rollers  70  in operation. 
     In the illustrated embodiment, the carriers  70   a  or carrier wheels  70   a  ride on top of the bottom tubes  64  of the truss  60  or flange of an I-beam  12 . Nevertheless, the axles  72   a  thereof need not be exactly horizontal on tubes  64 . Force vectors that are not exactly vertical may support the trolley  30  vertically  13   c  on the track  12 , even if the exact angle of the axle  72  is not horizontal. Nevertheless, in the illustrated embodiment, the carriers  70   a  rotate on a horizontal axle  72   a,  as do the idlers  70   b  on their axles  72   b.  Meanwhile, the guides  70   c  operate or rotate about vertical axes  72   c  to maintain lateral  13   b  tracking of the trolley  30  along the track  12 . 
     The cart  30  is relatively sophisticated and expensive, more than just a conventional trolley. It has the main housing  74  or frame  74  that carries the rollers  70 , both lateral stabilizers  70   c  and vertical load  29  carriers  70   a.  Outside are the neodymium magnets  80  which operate in an eddy current braking system  29  under the Lorenz effect (a moving magnetic field drives a current, a moving current carrier creates a magnetic field). 
     The trolley wheels  70  or rollers  70  may act as a suspension system. To a certain extent, when rollers  70  or wheels  70  are formed of a comparatively softer rubber, or a composite wheel and tire, a certain compressibility may be available on each of the rollers  70  when under load. When a wheel  70  compresses, it may operate as a suspension, as a spring, and also as a modifier of tolerances. 
     For example, the wheels  70  may actually be under compression at all times, causing certain frictional losses in rolling, but providing a tighter tolerance or closer tolerance between the wheels  70  and the bottom flange  17   a  of a track  12 . Moreover, even if tolerances are set to provide open gaps between, for example, idlers  70   b  below or guides  70   c  beside a track  12 , and the track  12  itself. 
     On inclines and declines and possibly on turns, the use of a compressible wheel  70  provides trolleys  30  that proceed through bends sideways  13   b,  and up and down  13   c.  Similarly, the guides  70   c  may provide a certain amount of give in compression in order to accommodate turns in a lateral direction  13   b  of the track  12 . With solid metal wheels, additional suspension systems (e.g., springs) would be required for a smoother, quieter ride. 
     Referring back to  FIG. 31B , again, a harness assembly  31  or seat assembly  31  may include its namesake the seat portion  120  or simply straps of a harness. It is typically preferred for throughput to have a seat portion  120  and back portion  123 . Meanwhile, these are both suspended by the straps  122  or slings  122  extending a suitable length from fasteners  121  such as carabiners  121  connected to the apertures  112  in the end plates  106  of the yoke  100 . 
     In the illustrated embodiment, a safety bar is somewhat loosely swung from the front straps  122  to be easily lifted above a rider, and then snapped by a buckle into a center strap. In this way, a rider may be rapidly loaded and secured by simply lifting the safety crossbar overhead while loading the rider, then dropping the crossbar to the rider&#39;s lap, where it will snap by a buckle shared with the central seat strap  119   a.  Meanwhile, other safety straps  110   b  may be placed elsewhere as mechanisms for support for the seat  120 , the back  123  or simply for restraining smaller riders against escape or falling from the harness system  31 . Thus, although a climbing harness represented only by leg straps and a waist belt connected by slings is possible, comfort, safety, ease of loading and unloading, and so forth are all expedited by a harness assembly  31  or seat assembly  31  as illustrated. 
     Referring to  FIG. 35 , an eddy current braking system  29  (ECBS  29 ) may include brackets  79  connecting to a rail  12  of a trolley system in accordance with the invention. For example, in the illustrated embodiment, magnets  80  are mounted on a plate  82  secured to a trolley  30 . As a practical matter, the plates  82  may be secured to the trolley  30  or to the brackets  79  on the rail  12 . 
     That is, a current plate  83  is designed to have a length  81   a,  a width  81   b  or height  81   b  (intra vertical plane as illustrated), and a thickness  81   c.  Meanwhile, the current plate  83  may be spaced away from the magnets  80  some clearance distance  81   d  or clearance  81   d.  For convenience, consider that the distance  81   a  or length  81   a  over which braking will occur may be several feet. Five feet has been found a sufficient distance suitable for bringing a rider to a halt at a comfortable deceleration rate. 
     However, the plates  83  or current plates  83  illustrated as flanking the rail  12  on both sides or the trolley  30  on both sides could reverse location with the magnets  80  to the same effect. Nevertheless, inasmuch as the length  81   a  may be selected to be comparatively long (compared to magnets  80  of about an inch cubed, 2.54 cm), it makes more sense for the trolley  30  to carry the magnets  80  secured to and by the mounting plate  82  on the trolley  30 . 
     In certain embodiments, the distance  81   d  or clearance  81   d  may be adjustable. Magnetic forces tend to decrease as the square of distance  81   d  or clearance  81   d  between the magnets  80  and the current plate  83 . So a slide adjustment of the clearance  81   d  may be very useful. Moreover, in order to further smooth or slowly introduce braking forces on the trolley  30 , the clearance  81   d  itself may vary from a greater to a lesser distance  81   d  between the magnets  80  and the current plate  83 . 
     Accordingly, the brackets  79  may be provided with slots  77  through which bolts  75  may be placed. Thus, the clearance  81   d  variation along the plate  83  may be adjusted. Typically, if the current plate  83  is solid then any clearance  81   d  variation will necessarily be linear from one end of the plate  83  to the other. 
     Also, it is illustrated to have two sets of magnets  80  and two current plates  83 . This is not necessarily so. A single current plate  83  may be adequate. Nevertheless, in order to balance forces applied to both sides of the trolley  30 , and reduce any twist, torque, or couple in the yaw direction (rotating about a vertical axis  13   ac ), the balancing of forces is desirable. Moreover, undue wear or stress may occur in certain of the wheels  70 , such as the lateral guides  70   c.    
     Although not illustrated, for clarity, a bolt  75  may be secured into each slot  77  of a bracket  76 . Likewise, the framing  85  that supports the current plate  83  may or may not be a part of the current plate  83 . 
     For example, if the framing  85  is conducting and is electrically connected to the current plate  83 , then eddy currents may circulate within the framing  85 . On the other hand, insulation may be placed between the current plate  83  and the frame  85  to preclude current circulation through the frame  85 . Similarly, the frame  85  may be made of a dielectric material. Nevertheless, considering the braking forces, a robust construction has demonstrated that framing  85  of metal, such as steel or aluminum has served well. 
     It is worth noting that the engagement distance between the plate  83  and the magnets  80  affects the amount of eddy current generation within the current plates  83 . Accordingly, the brackets  79  may have slots  77  with bolts  75  to adjust laterally  13   b  the framing  85  and current plates  83 . 
     Similar slots  77  may be placed on vertical surfaces of the brackets  79  to provide vertical  13   c  or transverse  13   c  adjustment of the current plates  83  with respect to the magnets  80  on the trolley  30 . Thus, the amount of vertical  13   c  engagement distance or overlap may be adjusted between the magnets  80  and the current plate  83 . In the illustrated embodiment, the magnets  80  are illustrated as positioned approximately parallel to a center line proceeding longitudinally  13   a  along the center of the width  81   b  of the current plates  83 . In alternative adjustments, the magnets  80  may actually extend out over the edges of that width  81   b  (vertically oriented, therefore height may be used to describe this dimension  81   b ), thus reducing the effective magnetic engagement between the magnets  80  and the current plate  83 . 
     An eddy current braking system  29  (ECBS  29 ) may include a bracket  82  (plate  82 ) under (or behind) the magnets  80 . Another bracket  79  connects the “current plate”  83  to the rail  12  or track  12  by adjustment bolts  75  allowing lateral adjustment of clearance  81   d  between magnets  80  and the “current plate”  83 . The current plate  83  may be about three inches in height  81   b,  five feet in length  81   a,  and may include a thickness  81   c  of about ⅜ inch (1 cm). An aluminum plate may be tapered and may have an offset or clearance between it and the magnets  80  of about ½ inch. 
     The ECBS  29  may have a clearance  81   d  between magnets  80  and a current plate  83  out to an inch or more and can still have a braking effect because of the strength of the magnets. The clearance  81   d  may be adjusted down all the way to ⅛ inch (3 mm) or less. Moreover, the clearance  81   d  may taper it so the different weights of riders would slow at similar rates and stop in different distances or the same distance with different forces. 
     A combination of factors may be used in engineering the eddy current braking system  29 . For example, a downhill slope of the rail  12  should be about four degrees, because the ECBS  29  only generates magnetic braking forces when the trolley  30  is in motion, and is velocity dependent. So, a downhill slope assures that all riders or users are going to continue moving to the end. They will each slow down to the same slow constant speed. 
     The ECBS  29  may be a long linear system. As a trolley  30  enters a braking region, it can engage the magnets  80  and plate  83 . Clearance  81   d  may be an inch, tapering and then down to approximately ⅛ inch (3 mm) or less. That creates a changing braking force depending on the relative linear position of the trolley  30  with respect to the ECBS  29  region at any given moment. One reason this is helpful is that the light braking force allows comparatively light riders to come in and experience an acceptable deceleration force. Mechanical braking does not automatically adjust so. 
     In one embodiment, magnets  80  and plates  83  may become closer and closer together along the longitudinal direction  13   a.  Any rider or user who passes that ECBS  29  location at a comparatively higher speed gets a comparatively higher force applied. A rider or user may naturally push farther and farther into the ECBS  29  depending on their weight and the ECBS  29  may assist such regulation by including the modest rate of elevation  13   c  decline at the end. 
     The system  10  may still include some energy recovery from elevation change of the trolley  30 . The ECBS  29  need not stop a rider fully at any given point. Rather, users or riders may stop at the same spot but will slow down due to a force characteristic of their weight. The system  10  is safe and need not include anything physically touching the rider or trolley  30 . 
     Any suitable magnet  80  may be used in the ECBS  29 . Also, plates  83  and magnets  80  may switch places. In one embodiment, the magnets  80  may be neodymium cobalt magnets  80 . Other suitable magnets  80  may include a samarium-cobalt, rare-earths, electro-magnets  80 , and even aluminum-nickel-cobalt. 
     One may accurately predict how the brakes will respond to the entire range of riders. However, there are sometimes quirks discovered on site that make a pre-determined braking scheme less than optimal. Before use of the damping system, one may also add in braking sections to slow carts down before they go into a corner, which keeps the amount of lateral swing down. This may usually be empirically determined by feel, trial and error, analysis, or some combination of methods and adjustment. Damping is preferably tuned so it is biased toward heavier riders. It is more comfortable to over-damp the system for light people than it is to under-damp it for heavier, and the difference in response between the weights is small, as discussed above with respect to pendulum and drag theory. 
     Again, speed control of a rider in a conventional roller coaster is done by selecting the angle of incline and the angle of decline along a track  12  associated therewith. Similarly, the track  12  may be bent in a transverse (vertical) direction  13   c  to replicate or mimic a roller coaster that has a continuing series of decreasing maximum altitudes and corresponding descents. Nevertheless, in certain embodiments, the track  12  may continually descend once a trolley  30  is released from the lift system  24 . Accordingly, it may be beneficial or desirable to put periodic braking along the rail  12  in order to modify speed appropriately. This may be done by adding an ECBS  29  of a suitable length at any particular point along the track  12 . This may typically occur just prior to particularly sharp corners, or the like. It will necessarily occur at the end of the ride. 
     In the discussion of the ECBS  29 , it was pointed out that the current plate  83  is set at a clearance distance  81   d  away from the magnets  80  on the trolley  30 . Of course, the positions may be reversed, but space tends to militate in favor of this particular configuration. Accordingly, the clearance  81   d  may change in a lateral direction  13   b  with progress in a longitudinal direction  13   a  of a trolley  30  along the track  12 . 
     That clearance distance  81   d  may actually be actively controlled by moving the current plates  83  toward or away from the magnets  80  of the trolley  30 , within certain limits. The braking system (ECBS  29 ) may be rendered (smart) by actively measuring by a sensor a patrons&#39; speed at some location. A simple set of light sensors indicating position, and timer permit speed to be calculated using a time clock. Altering the clearance  81   d  may adjust the brakes according to the speed of the particular trolley  30 . 
     The system  29  may also be modified by weighing a patron and trolley  30  on a particular section of track  12  provided with sensors for the purpose. Many types of sensors exist, including strain gauges, scales, separable platens supported on springs and provided with transducers, or the like. 
     Weighing a patron and trolley  30 , then comparing a velocity and change in velocity, may provide for a computerized calculation of braking variables. Control may be the engagement alignment in a vertical direction  13   c  between the magnets  80  and the current plate  83 . It may be the engagement distance  81   d  or clearance  81   d  between the current plant  83  and the magnets  80 . It may be both. Thus, weight may be measured, and communicated to a processor for modifying the brakes or accelerators along the track  12  according to anticipation of that particular patron arriving at a particular location on the track  12 . 
     For particularly long spans, the ramp portion  26  may be comparatively longer, or may be done in stages, including a first ramp upward, followed by leveling out and then a subsequent ramping portion  26 . 
     Sensors to detect position, weight, speed, and the like may be installed along the track in order to assure no interference exists between riders. That is, to the extent that different speeds are calculated, permitted, or simply occur between adjacent riders, a set of sensors detecting positions installed in order to automatically adjust braking, or the like, in order to slow down when patrons separate their trolley  30  from a previous or subsequent trolley  30 . 
     Certain designs contemplated for trolleys  30  may connect and disconnect as in a conventional roller coaster. For example, standoff rods illustrated on the trolleys  30  hereinabove may be connected to provide a train of trolleys at specified distances apart. Meanwhile, trolleys  30  may be connected and disconnected by a suitable automatic or manual connection system. 
     Since braking force equals a mass times a deceleration, the amount of mass being stopped will depend on rider weight or the number of riders in a train of trolleys  30 . Accordingly, in order to equalize braking forces, current plates  83  of ECBS systems  29  may be extended to greater lengths  81   a,  or additional ECBS current plates  83  may be installed. Also, the actual clearances  81   d  between current plates  83  and magnets  80  on a particular trolley  30  may be automatically adjusted based on sensing how many riders, how much weight, or the like may be approaching the plates  83 . 
     In certain embodiments, the ECBS  29  may tend to operate to slow each rider alone, even when concatenated together by connecting rods spacing trolleys  30  apart from one another, but holding them together. Since the magnets  80  are on the trolleys  30 , with the electrically conductive current plate  83  on the track  12  or fixed with respect to the track  12 , the weight carried by each trolley  30  is handled by the magnets  80  on that trolley  30 . 
     Thus, braking need not be adjusted by the number of carts  30  or trolleys  30  in a train. Nevertheless, each rider will simply experience braking according to velocity. However, more trolleys  30  in a train would involve more mass, and therefore less effect or less deceleration occurring due to a set of magnets  80  from a single car passing through the ECBS  29 . 
     However, the next trolley  30  in line would then pass through the current plate  83 , followed by another trolley  30  with its magnets  80 , thus each acting on the entire train to the extent justified by the speed and passage of the magnets  80  on each individual trolley  30 . The end result then is that the train comes to a stop but in a slower rather abrupt fashion. 
     That is, the braking process occurs over a greater period of time since the magnets  80  are naturally distributed between or among the trolleys  30 . Thus, in general, each trolley carries some amount of load, but concatenated trolleys  30  would simply assign the braking force to each trolley  30  in turn as it passed between the current plates  83 . 
     In certain applications, such as a roller coaster, the number of carts  30  or trolleys  30  per train may vary from three to perhaps six or eight as in conventional roller coasters. Of course, this will depend to a certain extent on the loading platform  22  and its spatial provisions. As described hereinabove, brakes will not need to adjust, because each can be set for an individual trolley  30 , according to its rider. 
     To the extent that trolleys  30  may be traveling together, in a train, a standoff or shaft, rigid and sufficiently long to separate trolleys  30  from one another safely, may be connected between adjacent trolleys  30 . Preferably, the shaft is connected quite securely, with comparatively small tolerances in order to not permit backlash or “swap” sometimes referred to a slack in the train. Everyone has heard a freight train starting up, as each car in turn has the slack taken up between it and the car ahead of it. 
     Thus, continuing set of resounding thuds occurs as each car is pulled in turn. Likewise, a train braking creates the same phenomenon as cars use up the slack between themselves and the adjacent cars and slam together. In order to minimize this, a toe shaft or standoff shaft may be fixed or even built into a trolley  30 . Accordingly, this provides for an absolute rigid body motion between the shaft and the trolley  30 . 
     Nevertheless, a connection will need to be of modest tolerance, and may have a bumper or elastomeric fitting in order to ease any tolerance in, and permit tightening together. In this way, shafts positioned between trolleys  30  in a train may render the trolleys  30  a train that operates more-or-less as a single unit. 
     Various apertures discussed hereinabove require pins or bolts to secure them. Each has benefits. In some respects, a bolt tightened down to a suitable torque, and then fitted with a pin, such as a cotter pin or cotter key through a hole crossways through the bolt may provide suitable safety. 
     The brackets  76  by which the current plate  83  secures to the rail  12  may be formed of a ferrous material. Meanwhile, the current plates  83  themselves needs not be formed of ferrous material. Nevertheless, for strength, weight, or other considerations, some alloy, including a perforated plate  83  may be fabricated of ferrous, non-ferrous, combination, including dielectric materials. 
     Referring to  FIG. 36 , equations illustrate the control for adjustment and the number of apertures  99  in the tab  76 . The adjustment angle is designated by the Greek letter θ the number of holes  99  or apertures  99  within a tab  76  is designated by the letter n. Meanwhile, the angle θ is the arc  105   b.  The adjustment angle θ of the tab  76  is the arc  105   a  or differential angle between adjacent apertures  99  and the tab  76 . The θ of the tab  76  is shown for the angle  105   a  in equation 1 through equation 4. 
     Thus, there are three significant angles  105 . These are the effective adjustment  105   c,  the differential angle  105   a  between the adjacent apertures  99  of the tab  76 , and the differential angle  105   b  between adjacent apertures  101  of the panel or frame  74 . Equations 1 through 4 demonstrate that the angle  105   a  needs to be the angle of the adjustment desired multiplied by ‘n’ (the number of holes  99  in the tab  76 ) minus 1, all times that adjustment angle  105   c.    
     This is derived from the fact that the θ of the tab  76  divided by the θ of the frame  74  (angle  105   a  divided by angle  105   b  should equal one less than the number ‘n’ of apertures  99  in the tab  76 , all divided by that number ‘n’ of such apertures  99 ). 
     Effectively, the incremental angle  105   c  or θ of adjustment  105   c  then becomes a simple difference between angle  105   b  minus angle  105   a.  Equation 3 shows that the angles  105   b  in the frame  74  (the panel  74 ) should be the adjustment angle  105   c  multiplied by the number ‘n’ as the number of apertures  99  in the tab  76 . 
     Likewise, control of the spacing of the apertures  101  in the panel  74  or frame  74  and the apertures  99  in the tab  76  are described in equations 1 and 2 as well as equations 5 and 6 illustrated. The numbers for a typical system are illustrated by the values column in the chart of  FIG. 36 . 
     Here the number ‘n’ again represents the number of apertures  99  in the tab  76 , while the panel angle  105   b  is θ of the panel  74  and the tab incremental angle  105   a  is the θ of the tab  76 . The θ of adjustment is the angle  105   c.  As can be seen by the repetition of equations 1 and 2 that still apply, the available adjustment angle  105   c  is equivalent to the panel angle  105   a  less the tab angle  105   b.  When these equations are reconciled together, the number ‘n’ of apertures  99  is defined by the panel angle  105   a  divided by the difference between the panel angle  105   a  and the tab angle  105   b.    
     In the chart of  FIG. 36 , equations 1 through 4 are used where arc length is an input. This allows a convenient comparison of fastener size and hole spacing. In contrast, this set of equations including equations 1, 2, 5, and 6 uses an angle as input. This shows that the calculation is considerably less convenient when angle is used for comparison. 
     These equations 1 through 6 rely on the relationship between the apertures  99  in the panel  74  or the frame  74  and those in the tab  76 . The value of ‘n’ is unitless because it refers to simply a number of apertures. The units of angle are consistent and can represent the arc length or the angle. This is because arc length and angle are related based on the calculation that 360 degrees represent  27   c  radians of angle. Angle relates directly to radius and arc length by the equation saying radius times angle in radians equals arc length in unit distance. 
     Referring to  FIG. 37 , braking force is defined in terms of equation 7, where ‘F’ is braking force. In equations 7 through 10, the letter ‘p’ equals the number of magnets  80 . The letter ‘s’ is the conductivity of the current plate  83 . Typically, this may be influenced by the percent of copper therein. 
     The designation of ‘d’ and particularly ‘d 1 ’ represents the thickness  81   c  of the current plate  83 . The letter ‘l’ is the length of a single block magnet  80  of the several stacked up together on the base plate  82 . The letter ‘C convert ’ is a conversion value from percent copper to units of electrical conductivity. The letter ‘B r ’ is known as a remanence field or residual magnetism given in teslas. This is available from suppliers of magnets  80 . 
     The letter ‘D’ represents the thickness of an individual magnet  80 . Calculated values that vary as part of the design process include ‘a’ as a geometric constant for a particular magnet  80 , including its material properties and so forth. The letter ‘B s ’ represents a magnetic flux density. The units of magnetic flux density are typically in gauss and may be determined by repair to any handbook of material properties and electrical or other technician or engineering terminology. The letter ‘z’ represents an instantaneous distance (clearance  81   c ) from a face of a magnet  80  to the current plate  83 . 
     Calculated values resulting include the letter ‘F braking ’ as an instantaneous braking force acting on the magnets  80  and consequently the trolley  30 . The letter ‘v’ represents the instantaneous velocity of the magnets  80  with respect to the current plate  83 . The parameter ‘c s ’ is a place holder value to simplify the equation display wherein braking force is equal to the number of magnets  80  times this place holder times velocity. Of course, the velocity is relative velocity between the motion of the magnets  80  and the current plate  83 . 
     Thus, equation 7 defines the braking force, while equation 8 defines the place holder value. Meanwhile, equation 9 defines the geometric constant for the magnets  80  in terms of their dimensions defined hereinabove. Accordingly, the magnetic flux density is defined by equation 10. 
     These calculations begin with an initial velocity calculated, measured, or estimated by a technician or an engineer. This is used in calculating a predicted braking force. That braking force is applied as a constant over a small period of time and integrated over that period of time to determine a new velocity. This process may be repeated (iterated) until a designated time has passed totaling seconds or fractions of a second of a braking event. At this point, the deceleration is continually calculated. 
     The equations may be executed for multiple designated weights. As it turns out, by incrementing in time differentials of about 3 milliseconds, an integrated braking force and deceleration may be calculated over a period of a second to a few seconds. When the calculations are run at different weights, representing different weights of bodies seated in the harness system  31  or assembly  31  under a trolley  30 , the velocity, acceleration, and braking “g forces” experienced by a rider may be calculated. 
     Initial lifting may be done by a sprocket system driving a drive chain, continuously in a single direction or cycling back and forth. Retrieval may be required from where the drive chain releases the cart  30 . 
     In one embodiment, a drive chain runs through a set of three idler sprockets. The bottom sprocket is fixed in a frame and runs the chain under it. The chain then runs up and over a top idler which idler has an adjustable screw that will lift or lower it. The chain runs up around the top of it and then down around a second bottom fixed idler. Thus, every centimeter of lift on the top idler yields two centimeters of length taken out of the chain. From the bottom idlers, the chain goes out to the motor sprocket, driven by the motor, and thence to another alignment sprocket fixed on the rail  12  of the lift system  24 , which establishes the path of a sprocket fixed to the lift unit  32  (trolley  32 ). 
     The lift unit  32  may have a little one way toggle  92  (swing arm  92 ) that serves as a ratchet. It lifts over periodic stops (obstructions) freely, moving forward. It then drops down below the cart  30  denying the cart  30  to back up past it. Similar toggles  92  may be placed on the opposite side of the cart rail  12  about every four feet to act like a ratchet. A small polymeric bumper may be added on that so that the swing arm  92  (toggle  92 ) doesn&#39;t clank metal on metal as the cart moves upward past each one. Damping is done to reduce the impact and sound. 
     Being able to finish out the ride in the absence of main power may be very important because otherwise there has to be extensive rescue equipment. For example, a man lift or the like would be needed to retrieve a person from the coaster cart. In one example, 4 amps on 220 volts run through a motor controller. However, if a separate gear system is used, it can run on 110 volts with about 3 amps, at considerable savings. A battery can provide power to an inverter and A/C increasing the 12 volts. The effect of this system is if on the lift portion of the ride one has a power failure and the system has people on the lift portion of the ride, the motor will at least have sufficient energy provided from the battery through the inverter to lift those riders onto the completion of the ride because they cannot back up with the toggle safety  92 . So, at that point they would be able to finish the coast. 
     Any time the system is stopped, it does not reset. That is, it does not zero out its memory. Rather, it remembers where it was on the path as far as the lift unit is concerned. Therefore, if for any reason, because of fearful riders or because somebody accidentally hits the stop button, or somebody screams and somebody hits the stop button but nobody knows why, hitting the “on” button or “go” button returns a system to its previous condition. That is, it remembers where it was and simply continues from there rather than requiring any resets. 
     Variable frequency drive controls the motor going forward. Returning may be included. The motor can be controlled as far as its speed and lifting riders to the sendoff point as well as controlling the speed of the return of the motor unit or drive unit. 
     The system  10  may have proximity sensors that add inputs for a control algorithm. By having proximity sensors at each end, the motor unit, drive unit, or lift unit, or the like has an absolute sensibility to its position at all times. 
     In prior art systems, for example, distance may be calculated from a counter. Thus, if a cog slips a tooth, strips, or otherwise loses its count, it has lost its way and is an open loop control. Here, there is always a closed loop control based on absolute position due to proximity sensors. 
     The motor control also provides control for an acceleration rate of the motor along a gradual course. The rate of acceleration of the motor getting up to drive speed can be controlled as to its rate and the integrated rate over time. It may dictate maximum velocity. Being controlled in both directions, the rider never feels an instantaneous jolt. 
     In contrast, maximum draw of current, and therefore maximum power results from the motor at zero velocity when it his turned on. Controllers preserve the motor against overloading or excessive current. Ramping it up to speed and decelerating it at some conditional rate limits currents, fluctuations of velocity, and uncontrolled draw of power. Variable frequency drive with digital signal, inputs reduce the number and the duration of the voltage pulses controlled by the variable frequency drive, VFD. 
     One of the other control mechanisms is to adjust cycle times. For example, the number of seconds a rider spends on the ride needs to be more than the amount of time that it takes to equip another rider, place the rider in the cart, and launch that cart on the lift portion of the ride. Accordingly, the observed cycle time of the cart may be calculated and used as an input in order to control how fast the motor unit or lift unit will return to the loading deck. Thus, a returning rider does not collide with a loading rider. 
     The lift time and the return time of an individual rider to load up another rider and send them to the top of the ride may be calculated and measured empirically. These times can be evaluated and used for control. Return time, again refers to return time of the rider. There is also a return time of the motor unit or the drive unit. The return time of the drive unit need not be excessively fast if it can be calculated into the return time of the rider. Thus, there is the lift time of a rider, the return time of the rider. The return time of the motor unit must coordinate with the next rider. 
     The magnet system may be unique in that the magnets  80  have undergone three shifts. First of all, they were changed from electro magnets  80  to permanent magnets  80 . This allowed shift number two which means the magnets can be moved from the fixed frame or structure onto the moving trolleys  30 . Thus, every trolley  30  is individually braked. Then, each can be tuned by adjustment of the distance  81   d  of the plate away from the magnets  80  (distance to the third power and velocity to the second power, actually, reciprocal distance to the third power and speed to the second power are proportional to braking force). 
     By putting the magnets  80  on the cart  30 , carts  30  can be “convoyed” or “trained” as a mechanism to link them together as in a conventional roller coaster to travel in trains with each cart will have its own braking. In this way, the brakes may be tuned for the rider to be from about 45 to about 250 pounds and still be adequately braked without undue stress, without too abrupt a braking force, or otherwise inducing any discomfort on the user. Nevertheless, no matter how long the train, every cart  30  may have its own braking sufficient for its own rider. 
     One of the other influences here is the fact that the current plate  83  for the ECBS  29  may be of any desired length  81   a  and may be spread in any distance  81   d  apart. One significance of this is the fact that the plates  83  generate eddy currents and therefore no individual cart  30  picks up the resulting heat. Thus, the duty cycle of the plate  83  is comparatively smaller. Magnets  80  pass by only once every trip as one cycle with one passenger. 
     An eddy current brake  29  may have a relationship requirement between the length  81   a  of the current plate  83  and the length of the brake magnet bar  82  and magnets  80  mounted thereon. The magnetic forces have an “edge effect” near their beginning which tends to draw the magnets  80 . Here, where the plate is aluminum but it is connected to steel bar, it has an edge effect at the end. 
     Originally, when the brakes were done with multiple plates at a certain distance the edge effects could then dominate. Thus, it has become preferred to provide a plate that is comparatively long, in this case about five feet (1½ meters). The brake magnets  80  constitute a bar of five magnets  80  about a 1½ inch (4 cm) each for a total of about eight inches (20 cm). 
     The track  12  or cart rail  12  never need move, and may never need to turn in more than one direction (degree of freedom) at a time. This allows for manufacturing alignment and for manufacturability of all the components. Also, the turntable attachment scheme provides for adjustment in place rather than conventional precision welding. Meanwhile, conventional tube type tracks require precision bending in several degrees of freedom. They are welded in place with struts between them. Here that is not required. The beam is heated to bend it but need only bend either up or down or else right or left at any one location. 
     A system as described herein may be combined to include a laser-tag-type shooting gallery with targets on outside walls, inside supports, on seats  31  or suspended from carts  30 . Likewise, interactive virtual reality (VR) systems, goggles, helmets or accessories may be provided for action rides set in any virtual setting from wild-west, to futuristic types. Trolleys  30  may be motorized with power provided with the rails  12  or other mechanisms (batteries, cables, etc.). Lift systems may be provided with battery back up to clear riders from the ramp portion  26  in the event of a power or motor failure. 
     Just as the yokes  100  pivot, joints may be added to permit the rider and harness to pivot or even rotate in additional degrees of freedom (e.g., pitch, yaw) below the trolley. 
     Cycle Time is dependent on the particular installation. One may want to make sure that an operator can&#39;t accidentally put people on too fast. For systems of any significant height, the amount of time spent on the lift hill (ramp portion  26 ) maintains this separation by virtue of just taking time. A variable frequency drive (VFD) for the lift system  24  may be set to return the lift trolley as quickly as is practical. 
     Separate control systems may be devoted to cycle times. Some riders like a thrilling, comparatively very high point to start. Exact timing may be decided by using a simple sensor and timer. Measurements for heaviest loads and lightest should theoretically be identical, but friction of mechanical mechanisms and air drag alter that theory. A cycle time will be limited by the slowest descent. Ideally, the lift system would be running at all times, and an exiting rider would be reaching the bottom of the lift hill  26  just as the lift trolley returns to the low position. 
     One embodiment may include a continuous lift system (rather than a reciprocating, “fetch” system). Timing when riders are released onto the track  12  may be limited by a suitable spacing and timing needed for the fastest subsequent rider following behind the slowest leading rider, in order to maintain safety. So a Light Rider Time, less a Heavy Rider Time, plus a loading time or time gap for safety may be the Release Time. 
     In certain embodiments, the harnesses  31  harness systems  31  may be designed such that patrons (riders) ride side by side. In this way, a single trolley  30  may support the weight of multiple riders simultaneously. 
     The adjustment mechanism, based on the eccentric axles  72  inside the wheels  70  may permit adjustment of the wheel position also for the purposes of compensating for wear. This will necessarily change somewhat the diameter of a wheel  70  as it wears. It may alter somewhat its elastic (resilience) properties. It may be done to maintain the desired tolerance, any desired tolerance, between the wheels  70  and the track  12 . 
     The present invention may be embodied in other specific forms without departing from its purposes, functions, structures, or operational characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.