Abstract:
Persons on a bicycle or other muscle-powered vehicle, equipped through an attachment means, with a reaction plate secondary of a linear induction motor, LIM, receive intermittent, augmenting propulsion forces from a sequence of spaced LIM primary coil assemblies, positioned flush with a surface on a pathway, to augment the rider&#39;s muscle-created propelling forces when the LIM primaries are receiving power supplied by a utility. At each LIM primary, interacting magnetic fields are commonly created as the attached bicycle LIM secondary is moveably positioned by the rider proximately the centerline of a respective LIM primary. The augmenting propelling force results as thrust, derived from the interaction of the respective magnetic fields of the primary and secondary of the now temporarily completed linear induction motor at the respective, spaced locations of the primaries along the pathway. Selectively specified attachment means are provided to mount and to control the vertical position of the LIM secondary on the bicycle or other, manually-powered vehicle.

Description:
BACKGROUND 
     The field of this invention is bicycle travel and the use of a bicycle. 
     Propulsion power derived from the operation of linear induction motors, briefly known as LIMs, has been applied to rail vehicles, amusement park roller coasters, etc. 
     To date, muscle-powered vehicles, such as bicycles, equipped with power augmentation systems use either electric motors with batteries or gasoline engines. However, when those systems cease to operate due to dead batteries, fuel exhaustion or mechanical failure, riders are faced with the prospect of pedaling, pushing or abandoning their bicycles. The added weight of the power-augmentation systems further exacerbates the problem of moving the vehicle once those systems become dysfunctional. 
     In many instances, muscle-powered vehicles, such as bicycles, might be a more convenient and appropriate form of transportation. Instead, the public relies heavily on automobiles, contributing to congestion, smog, and other environmental damage. Other forms of public transportation, buses, light rail, van pools, etc, have proven increasingly expensive for public transportation and still contribute significantly to environmental damage with their emissions. 
     The LIM is made up of two separate components (i.e.) the primary coil assembly, hereinafter called the LIM primary, and a reaction plate secondary, hereinafter called the LIM secondary. The primary is designed and built commercially. The LIM secondary is designed and supplied by the LIM user. When these two parts are in close, three-dimensional proximity, and electric power is delivered to the LIM primary coil windings, a directed, traveling magnetic field is created. This field induces current in the LIM secondary which creates its own magnetic field. The interaction of the two magnetic fields generates the forces of linear motion. See Baldor catalog BR 1202, pages H-26 through H-29. 
     Following are some applications of powered bicycles and LIM motors: 
     Among bicycle patents selected are U.S. Pat. No. 6,976,551, issued Dec. 20, 2005, class 180/207, to Mr. Harold Spanski. It describes “A power-assist system for a bicycle by which the bicycle can be operated in various modes.” In the listing of modes, Mr. Spanski describes “ . . . a pedal-alone mode, a power-assist only mode, a pedal mode with power assist, and a coasting mode”. There are two overriding clutches in the system. The high RPM power source is carried on the bicycle and can be either petroleum based or electric. Among the stated desirable features is the fact that the system “can easily be incorporated in a typical prior art bicycle”. 
     A second bicycle drive is U.S. Pat. No. 5,237,263, issued Aug. 7, 1993, class 323/288, to H. M. Gannon as “Electric and pedal driven bicycle with solar charging”. “ . . . The preferred embodiment consists of a standard street bicycle with multi-speed transmission, plus an electrical propulsion system and a solar charging apparatus. This preferred embodiment is normally powered by a combination of motor and pedals, coupled such that either or both may provide power at any time . . . . ” 
     Among LIM patents selected are, U.S. Pat. No. 4,061,089, issued Dec. 6, 1977, in class 104/232, Mr. Elbert M. Sawyer illustrated and described his “Personal Rapid Transit System”, which is said to be a “ . . . land transportation system for a vehicle that is supported and guided by air bearings.” This patent describes his personal rapid transit system which utilizes LIM propulsion power. In Sawyer&#39;s system, “The vehicle requires no driver or motorman because a guideway determines the direction of travel . . . . The vehicle is propelled by a linear synchronous motor, LSM, when on the guideway. “A linear inductor alternator provides on-board electric power.” The vehicle has a capacity of four to six passengers and is constrained to stay on the track system. There are linear motor primary units embedded in the guide way and placed in juxtaposition with each other and having “cooperating secondary members” attached to the vehicle. The “ . . . motor segments are powered by commercial electric power lines, whose frequency is constant throughout the network.” The speed of the vehicle is regulated by changing voltage and frequency as applied to the LSM primary winding. There are ON and OFF ramps for access by the vehicle. 
     A U.S. Pat. No. 6,578,495, issued Jun. 17, 2003, class 104/292, to Yitts, et. al. is titled “Modular linear motor tracks and methods of fabricating same”. He notes in the Abstract, “These are integrated during the manufacturing in to a single component or module for ease of shipping and precision of installation at the site where the guideway is to be installed.” 
     Another U.S. Pat. No. 6,619,212, issued Sep. 16, 2003, class 104/292, to Stephan, et. al. is titled: “Method for achieving and maintaining desired speed on a guideway system.” In this method, as in Sawyer, there is a linear induction motor and a guideway system using “computer control system”. Cruising speed for this system is to be “ . . . at least 240 kilometers per hour”. The method of Stephan, et. al. addresses the propulsion of “a vehicle on an automated roadway system or guideway system.” Also involved is a need for using the linear induction motor to accelerate the vehicle, along with “providing speed instructions to the vehicle using the computer control system so as to cause the vehicle to use the alternate power source to maintain a desired cruising speed on a main section of the guideway system”. 
     None of the above systems lend themselves to a practical, low cost, light weight propulsion power and pathway system for the bicycle riding and commuting public. 
     SUMMARY 
     It is an objective to provide a means of linking the bicycle with existing population centers and transportation hubs as a practical enhancement to commuter travel through easily accessed propulsion power sources positioned in a pathway. 
     An apparatus is developed which permits the rider of a bicycle, or other manually-powered vehicle to utilize the power of multiple, temporarily completed linear induction motors, LIMs, comprised of separate LIM components, i.e., a LIM primary positioned in a pathway and a LIM secondary with attachment means, adapted to a bicycle. A utility provides the power source for the linear sequence of selectively spaced LIM primaries which function in a low power draw mode until a vehicle-mounted LIM secondary is positioned proximate a primary, at which time the increased power of the fixed LIM primary is developed to make a complete LIM motor and induce an electro-magnetic linear force in the attached LIM secondary on the bicycle, which force then urges the bicycle forward with power augmenting that of the rider, who guides and controls the bicycle. 
     The plurality of LIM primaries are selectively positioned with their top surfaces arranged flush with the ridable surface of a marked pathway on a road surface and spaced at predetermined distances in a linear progression. The spacing chosen is dependent upon the expected pathway slope and mass range of vehicles using the pathway. The spaced LIM primaries are adapted to a sub-surface ducting which joins conduit-covered power lines receiving power from a utility. In another embodiment, a fabricated pathway is positioned on ground level and anchored to an underlying right of way. The fabricated pathway has, in two or more embodiments, open, surfaces accessed from the end and either side with a sloping surface so that the rider of a bicycle is able to ride on or off on either side of the above ground pathway at a preferred location and partially enclosed, weather protected ridable surface, accessed from the end and one side only. 
     The bicycle, is guided by the rider along a marked centerline of the pathway to continuously position the bicycle&#39;s LIM secondary proximately parallel with the lengthwise centers of the succession of electrically powered LIM primaries. The low weight, per se, of the non-powered LIM secondary, secured with a selected attachment means to the frame of a manually powered vehicle, such as a bicycle, interacts with each electrically powered LIM primary in a pathway to receive the electro-magnetically induced, periodic thrust to the LIM secondary attachment on the bicycle. 
     The bicycle, with the light weight LIM secondary attached, in conjunction with the powered LIM primaries in a pathway, can provide convenient and more consistent travel for the bicycle commuter throughout larger metro areas. Moreover, people may now have a more practical method of accessing public transportation from outlying areas and being less affected by automotive congestion. Bicycle pathways, having less stringent structural requirements than conventional road surfaces, also use less of the primary building materials thus permitting lower cost pathways with LIM primaries receiving electrical power that may serve riders of bicycles along populated access routes leading to locales where public transportation is available to continue a longer trip. 
     The LIM primaries in a pathway offer a relatively high working efficiency for the apparatus, which requires electrical power for only a nominal thirty seconds out of every horizontal, 1.6 kilometers or one mile traveled. For the nominal three minutes of time that it takes to go 1.6 kilometers, the required power is applied less than 10 percent of the total transit time to give the intermittent, electro-magnetic thrust required to augment the rider&#39;s speed. The design speed of a nominal 32 kilometers per hour or 20 miles per hour, gives the definition of an electric bicycle&#39;s maximum speed, as taken from TEA-21, the Transportation Equity Act for the 21 st  Century. The propulsion power thrust is supplied only up to the design velocity chosen, at which point, there is no added thrust provided. The design builds in a safety element that is easily controlled by the rider who can guide the bicycle on and off the width of the visible centerline marking to change the degree of electro-magnetic boost thrust from maximum available to zero. 
     The same LIM primary power method can be electrically switched in polarity to cause the directed magnetic traveling wave of the LIM primary to move in the opposite direction, thus opposing the bicycle momentum force on downhill pathways, where the rider needs augmented wheel braking capability in wet weather in order to make a safer and quicker stop on wet road surfaces. 
     Thus, while there are a nominal 100 million bicycles in America, the stated Congressional desires, for the bicycle, as written in TEA-21, the needs of TEA-21 have not been effectively met with existing commuter bicycle designs and functionality. Among these needs are those made specific in SEC. 3039 (a), “Purposes—The purposes of this section are to encourage and promote the development of transportation systems for the betterment of the national parks and other units of the National Park System, . . . minimize transportation fuel consumption, reduce pollution (including noise and visual pollution) and enhance visitor mobility . . . ”. 
     Bicycles that are powered by relatively heavy, internal combustion engines or various, battery-driven, electric-powered means, have been developed over the years, giving the rider more on board power to augment the rider&#39;s own muscle power in travel and commuting. However, the internal combustion engine causes both noise and air pollution and impedes the easy handling of the bicycle. Heavy batteries, with lead, to drive an electric motor, require constant recharging and can run down at inconvenient times, necessitating more effort and energy to pedal the additional weight to an energy renewal point. Moreover, there are added problems and costs of maintaining and recycling battery materials. The net result of designs using such prior art is that the vast majority of bicycles in use do not reflect a public desire to make consistent use of the presently available types of powered technology for bicycles. 
     It is to be understood that the foregoing general description and the following detailed description and illustrations are exemplary and explanatory of the selected embodiments and are not to be considered as restrictive of other embodiments. 
    
    
     
       DRAWINGS 
         FIG. 1  is a side elevation of bicycle riders A and B pedaling on an uphill pathway and showing how only rider A is receiving a temporary thrust positioned over the LIM primary, while rider B is relying only on muscle power at the position between LIM primaries. 
         FIG. 2  is an enlarged perspective view of a first embodiment, a fixed LIM secondary mount to be used in an environment that is substantially unimpeded by obstructions or debris. 
         FIG. 3  is a left side elevation of a second embodiment wherein the fixed LIM secondary connection has a segment of flexible cable at the lower end which gives constrained flexibility to the secondary to handle slight surface bumps while eliminating any chance of adverse force feedback to the LIM secondary on the bicycle. 
         FIG. 4  is an enlarged detail view from  FIG. 3  showing the embodiment in greater detail. 
         FIG. 5  is a section taken along the view lines  5 - 5  of  FIG. 4  showing the side movement of the flexed cable in phantom. 
         FIG. 6  is a left side elevation, of the third embodiment of a bicycle mounted LIM secondary attachment means and lift rod vertical control, utilizing a cable and a spring-assisted, rotating, partial pulley segment showing the bicycle-mounted LIM secondary attachment means which is also shown in perspective in  FIG. 7 . 
         FIG. 7  is a left side perspective view of  FIG. 6  embodiment. 
         FIG. 8  is a left side elevation of the preferred LIM secondary embodiment on the bicycle. 
         FIG. 9  is a  FIG. 8  enlarged view circle. 
         FIG. 10  is an enlarged perspective view circle of  FIG. 9  attachment means and upper linkage with retraction springs. 
         FIG. 11  is a rear perspective of the bicycle with LIM secondary and LIM primary in phantom. 
         FIG. 12  is a  FIG. 11  view circle enlargement of lift rod attachment means. 
         FIG. 13  is a front elevation of the LIM secondary in the extended lower position and in the retracted position, in phantom, and also showing a cover in phantom. 
         FIG. 14  is a front view elevation cross-section, viewed along the arrows  14 - 14 , showing the preferred embodiment attachment in the lowered and raised positions, with the raised position and cover in phantom. 
         FIG. 15  is a perspective view of a LIM primary in a pathway segment as installed in a road surface. 
         FIG. 16  is a cross-section of road surface, showing a LIM primary installation. 
         FIG. 17  is a perspective view of a symmetrical, surface-anchored pathway for LIM primary installation with the on-ramp displaced for clarity. 
         FIG. 18  is a  FIG. 17  view circle, enlarged, isometric view of the entry cross-section area of the pathway. 
         FIG. 19  is a partially weather-covered set of surface-anchored, asymmetric pathway segments having entry and exit ramps. 
         FIG. 20  view circle of  FIG. 19  is an enlarged detail of the entry ramp area of the pathway. 
         FIG. 21  view circle of  FIG. 19  is an enlarged detail of the exit ramp area of the pathway. 
         FIG. 22  is a  FIG. 19  view circle enlargement, showing one of multiple, shallow, recessed surface areas on approach to the LIM primary which provides a wheel-guiding lead-in for the bicycle rider, toward the centerline of the LIM primary. 
         FIG. 23  is a cross-section of the asymmetric covered pathway segment and LIM primary installation. 
         FIG. 24  is a  FIG. 23  view circle, enlarged detail. 
         FIG. 25  is a block schematic of the LIM primary showing, the bi-directional nature of the directed magnetic traveling wave and relative polarity effects when the LIM primary is receiving power from an electric utility. 
         FIG. 26  is a block schematic showing the mechanical relationship of the bicycle affixed LIM secondary and the LIM primary. 
         FIG. 27  is a block schematic of the LIM primary electrical system installation, showing the relationship to electrical power supplied to the LIM primaries either positioned in a roadway or within a fabricated and anchored pathway. 
     
    
    
     DESCRIPTION 
     How a Person, as a Rider, Using a Muscle-Powered Vehicle Such as a Bicycle, when he or she is Applying Muscle Power to the Pedals and is Directing the Bicycle Along a Designated Pathway, Realizes the Bicycle is Receiving Intermittent Thrust Created by Spaced, Temporarily Completed Linear Induction Motors, Briefly Referred to as LIMs. 
     Riders A and B of bicycles  110 , are shown in  FIG. 1 , riding uphill along a designated pathway  41 , having a bicycle ridable surface  32 . Each bicycle is equipped with a secondary of a linear induction motor  38 , briefly referred to as a LIM and as an attachment  40 . The pathway  41  has multiple LIM primaries  36 , with each primary being selectively spaced apart from other primaries, and each primary, via circuitry, is receiving electrical energy from a utility source, not shown. 
     When the rider A of the bicycle  110  having the secondary  38  of a LIM reaches the location such as the primary  36 , receiving the utility electrical power and the rider has the secondary  38  of the LIM selectively placed to be close to the primary  36 , then the bicycle will soon be receiving a thrust created by a temporarily completed linear induction motor  34 , briefly referred to as a LIM. 
     As the rider directs the bicycle  110  equipped with the secondary of the LIM over each active primary of a LIM, there is created a traveling wave magnetic field that induces current in the secondary which creates its own magnetic field. Then these magnetic fields of the primary and secondary interact to create a forward thrust force applied to the bicycle. As the rider continues to direct the bicycle along the designated pathway, he or she realizes the advantages of the bicycle receiving these timely, intermittently created, forward thrust forces at the locales of the temporarily completed linear induction motors, briefly referred to as LIMs. 
     Rider B is shown with the LIM secondary between LIM primaries  36 , and is not receiving the intermittently created thrust that causes a complete LIM motor. 
     Fixed Attachment Means for the LIM Secondary on the Bicycle to be Ridden on Pathways Free of Debris. 
     The first embodiment of LIM secondary attachment means is shown in  FIG. 2 , where the bicycle is to be operated over unobstructed areas which do not require the lifting of the secondary. 
       FIG. 2  is a top, left side perspective view of a fixed link stem assembly  69 , with thumbscrew  115  secured to bicycle kickstand plate  117  on bicycle chainstay  91 , and attach plate  57 . The lower end of fixed link stem  68  is affixed to base  80  with fasteners  53  and base  80  is affixed to secondary  38  with fasteners  59  and washers  58 , positioned above primary  38 . 
     A Shrouded Cable Embodiment of an Attachment Means Used when a Bicycle Runs on a Pathway which is a Substantially Unencumbered Surface 
       FIG. 3 , a second embodiment, is a left side elevation of the bicycle  110 , showing an attachment means  48  for the LIM secondary  38 , where the bicycle is being ridden on an unencumbered surface with flexible shrouded cable  46  and brush  33  on the LIM secondary  38 . In phantom is shown the completed primary LIM  34  motor and LIM primary coil  36  with electrical cables  37  and positioned in pathway  41  with the bicycle tires upon ridable surface  32 . 
       FIG. 4  is a  FIG. 3  view circle, enlarged detail side view. Shown is a cable shroud assembly  48  with flexible cable  46  contained inside the shroud tube  55 . One attach plate  57  butts up against kick stand plate  117  and is affixed with thumbscrew  115  to the plate  117  with fastening means  54  and  131 . The base attach  51  is at the lower end and is affixed to the cable  46  with clamp bolt  54  and to LIM secondary  38 , consisting of aluminum sheet  50  and steel plate  49 , with fasteners  56  and washers  58 . Ridable surface  32  is shown as a part of pathway  41  and completed LIM primary  34 . 
       FIG. 5  is a  FIG. 4  partial cross-section projection along arrows  5 - 5  and viewed in the direction of the arrows, showing the flexible cable  46  as constrained by a low modulus material torus  47 , whose outer diameter is secured within the shroud tube  55  of the shroud assembly  48 . Shown also in the deflected position, in phantom, is the flexure cable  46  that constrains the LIM secondary  38  from moving sideways in to the area of pedal rotation and flexibly decouples the potential for the LIM secondary to transfer any extraneous forces back to the frame of the bicycle. 
     A Cable and Segmented Pulley Embodiment of an Attachment Means on the LIM Secondary Used when a Bicycle Runs on Normal Roughness Surfaces. 
     A third embodiment permits the LIM secondary to be positioned over the LIM primary, and is shown in  FIGS. 6 and 7  as a segmented pulley, cable and LIM secondary assembly. 
       FIG. 6  is a left side elevation of a bicycle  110  showing how the LIM secondary can be raised and lowered by the retractor means  70 , affixed to the bicycle frame with fastener  77 . The bicycle is on a pathway  41  and a ridable surface  32  over an electrically complete LIM motor  34 . Portions of power cables  37 , are shown in phantom on primary  36 . Lift rod  61 , which is used to lower and lift the secondary  38 , is constrained to substantially linear movement by affixed lift controls,  60  attached to bicycle down tube  39 . 
       FIG. 7  is a  FIG. 6 , enlarged, left side, detail perspective view of a partial pulley segment  71 , of the retractor means  70 , which uses a cable  74  to constrain the secondary  38  from excessive excursions to the side and into the plane of pedal rotation. The attachment means retractor  70  is secured to the dependent sides of the bracket  73  which is secured through the hole in the kick stand plate  117  with pivotable fastening means and bolt  77 , nut  78 , and washer  79 . The pulley segment  71 , with unused center flanged bearing  72 , is secured to the pulley mount channel  73  with an offset pivot bolt  85  and flat washer  79 , enabling the partial pulley segment to act as a fixed link, rather than a rotating pulley. Cable  74  is wrapped around the circumference of the partial pulley segment  71  and is held in place between the bicycle chain stays  91  with cable clamps  93  and thence around the partial pulley segment  71  to the cable thimble  75  between washers  76  and with pivot bolt  85  through bracket  95 , washers  79  and  76  and nut  87  against washer  79  and spherical bearing end  89 , from which extends partial lift rod  61 . Bracket  95  is held to the secondary  38  with fastening means  56  and washers  58 . The pulley segment  71  is spring-loaded in clockwise rotation, from the left hand side view, with spring  101  which is secured to pins  103  and  105  at each end of the spring to provide a lifting and rotational force when the secondary  38  is released from constraint by the lift rod  61 . Partial V-tension element  107  is secured around an eyelet (not shown) with nut  131  and is shown extending from below the top surface of pulley mount channel  73  and partially down toward the rear angled surface of the LIM secondary (not shown) to act as a stabilizing constraint against excessive rearward movement during retraction. 
     A Retraction Mode, Articulated Link Preferred Embodiment of the Secondary Attachment Means 
     The fourth, preferred embodiment is shown in  FIGS. 8 through 14 . There is a further, side-to-side rigidity of the elbow-shaped attachment with two spherical bearings which decouples any extraneous forces on the LIM secondary from feeding back to the bicycle frame. 
     In  FIG. 8 , a left side elevation of the bicycle and the LIM secondary  38  and attachment means  40  are shown as installed in the extended position over pathway  41  and ridable surface  32 . Flush-mounted and completed LIM primary motor  34  and partial power cables  37  attached to LIM primary coil assembly  36 , are shown in phantom. The lift rod  61  and lift rod assembly  60  are shown in relation to the bicycle frame  110  and affixed to bicycle front down tube  39 . 
       FIG. 9  is a  FIG. 8  view circle, enlarged detail of the upper attachment means. A channel mount bracket  113  having dependent sides is secured to bicycle chain stays  91  with a single thumbscrew  115  and through a hole in the bicycle frame kickstand plate  117  which is attached to bicycle chain stays  91  and permits quick removal of the channel mount bracket  113  if desired. A pivot bolt  109  passes through washer  76  and the channel mount bracket sidewalls and through coaxial holes at the top of two alike, rigid and parallel, primary attachment link arms  111 , allowing them to pivot around a horizontal axis fastener normal to the dependent sides of the channel mount bracket  113 . V-tension element  107  is partially shown extending below channel mount bracket  113 . Nut  121  holds eyelet  119  to channel mount bracket  113 , which anchors V-tension element  107 . At the forward end of the channel mount  113  is a channel stop bracket  123 , secured by fastening means  125  and washers  58 , which hold two adjustable stop bolts  129 , locked in place with nuts  131  against the channel stop bracket  123 . These two bolts impinge directly upon the thickness edges of the alike, rigid and parallel, primary attachment link arms  111  and permit an adjustment to the relative height of the LIM secondary (not shown) by providing a settable stop point for the primary attachment link arms  111 , which are allowed to pivot around fastener  109 , connecting link rod  88  through spherical bearing  89 . Induced forces on the linkage urge link arms  111  to break free of ball plunger  114 , threaded in to the dependent sides of channel mount bracket  113  and affixed by lock nut  116 . The transmitted force load path is then through the LIM secondary attachment means  40 , the link rod  88  and the primary attachment link arms  111  to the two adjustable stop bolts  129 , and thence through the channel mount  113  and to the kickstand plate  117  of the bicycle frame. Tension springs  101 , attached to anchors  102 , held with pins  105 , provide additional lifting force to attachment means  40  during retraction of the LIM secondary. The removal of the kickstand in the pedal area of the bicycle frame itself permits the various secondary attachment methods, but commercial kickstands are also available, such as that of Wald Manufacturing Co., Inc., Assignee for patent D294014 which may attach directly to the rear wheel axle, so that the rider may still have the ability to use a kick stand for the bicycle. 
     Further, in  FIG. 9 , the ball plunger  114 , retained in the dependent sides of channel mount  113  with a lock nut  116 , provides a settable force against the primary attachment link arms  111 , which prevents the tension spring  101  from retracting the LIM secondary attachment means  40  in its normal operational, down position. Should there be a frontal impact force upon the upward angled front of the LIM secondary  38 , noted in  FIG. 8 , the potential impact force causes the primary attachment link arms  111  to pivot backwards and free of the ball plunger  114  normal load, thus permitting the tension spring  101  force to augment the aft moving momentum of the LIM secondary  38 , not shown, and bring the assembly to an immediate upward and stowed position. 
       FIG. 10  is a rear perspective of  FIGS. 8 and 9  detail, showing the attachment means for all parts of the LIM secondary and its extension mechanism as detailed in  FIG. 9 . Eyelet  119  is affixed to channel mount bracket  113  with nut  121  and flat washer  127 . E-ring  66  constrains lift rod  61  against lift rod angle bracket  128 . 
       FIG. 11  is a rear perspective of the complete bicycle  110  with LIM secondary  38  over the completed LIM primary motor  34 , lift rod  61  and lift rod assembly  60 , affixed to down tube  39  behind wheel  190 . 
       FIG. 12  is an enlarged detail of the  FIG. 11  view circle, showing the details of the lift rod assembly  60 , lift rod  61  and lift rod collars  64 , set on lift rod angle guide  63  and all attached to the bearing plate  67  with screws  65 , which is held against the bicycle down tube  39  with tube clamp  62 , just aft of wheel  190 . 
     Cover Assembly to Protect the Attachment Means of the LIM Secondary 
       FIGS. 13 and 14  depict a two part cover which protects against foot strike or road debris affecting movable parts of the LIM secondary attachment. 
       FIG. 13  is a detail front elevation of the secondary  38  with brush  33 , in the lowered, and raised position, in phantom, as is cover  130 . Partial LIM primary  36  and power cable  37  are shown in phantom below ridable surface  32 . Rear wheel  191  is tangent to the ridable surface  32 . Cross-section arrows  14 - 14  cut the view. 
       FIG. 14  is a left side elevation of the cover  130  cross-section, in phantom, looking along arrows  14 - 14  and viewed in the direction of the arrows in  FIG. 13  and showing the lowered and raised, in phantom, secondary  38  and brush  33  with brush  33  over pathway  41  and ridable surface  32 . Brackets  95  and  128  affix to secondary attachment  40  over LIM primary  36 . V-tension rod  107  is retained with collars  108 . Lift rod assembly  60  is affixed to front down tube  39 . 
     Selected Pathways Having a Ridable Surface Over Positioned LIM Primaries 
       FIGS. 15 through 24  show pathway embodiments. 
     There are two major embodiments for a type of pathway  41 , which have a ridable surface  32 , with LIM primaries positioned with selective spacing. In the first embodiment, the LIM primaries are set in to a support block  98  which, in turn, is set in to a channel cut in to the road and the top surfaces of the LIM primaries are set flush with the road surface. In the second embodiment of pathway  41 , the ridable surface pathway itself is a module that is anchored to a ground surface right of way and is also connected to a utility, not shown, supplying electrical energy to the primaries. 
     A Pathway Having LIM Primaries Positioned in a Channel Cut in a Roadway Surface 
       FIG. 15  is a perspective view of a pathway  41  and LIM primaries  36  positioned in a street support block  98 ; E-channel  174  is positioned in the channel cut between top channel assemblies  159 , acting as bezels for primaries  36 . A centerline  42  allows the rider to guide proximate the center line of the active powered area of the primaries  36 . 
       FIG. 16  module is an enlarged cross-section of  FIG. 15  street support segment  99  with LIM primaries  36  and power cables  37  in pathway  41  with ridable surface  32  on a partial cross-section of street support block  98 . LIM support plate  152  is positioned on support block  98  and attached with fasteners  154 . LIM base  151  is secured to support plate  152  with fasteners  54 . Bezel  159  legs are shown with long E-channel  174 . 
     Modular Pathway with LIM Primaries is Anchored to a Ground Surface Right-of-Way 
       FIGS. 17 through 24  show LIM primaries positioned in anchored, modular pathway embodiments. 
     The symmetrical  FIG. 17  modular pathway  41 , allows riders to get on and off at almost any location along the length of the system, owing to gently sloping sides. 
       FIG. 17  is a full perspective view of a LIM primary installation in a fabricated symmetrical base pathway  150  and pathway entry ramp  153 , shown displaced, for clarity, from its normal connection to the pathway segment. Guide pins  155  connect with the base  150 . Top channel bezel  159  is disposed around LIM primary  36 . E-channel  157  extends the top surface of pathway  41  and is shown with centerline  42  and anchoring holes  156 . 
       FIG. 18  is an enlarged, partial detail of  FIG. 17  view circle showing top channel bezel  159  with LIM primary  36  and power cable  37  set on LIM base  151  and LIM primary support plate  152 . Bolts  154  retain both parts to base  150 . 
     Modular Pathway with LIM Primaries for Riding and with Weather Protection 
     Where it is desirable to have the commuter protected against nominally adverse weather conditions, a covered pathway  41 , with centerline  42 , allows usage over a wider range of weather conditions. 
       FIG. 19  is a perspective view of asymmetrical pathway  160  with details, track projection light  170 , window wall  162 , roof  164 , roof edge  166 , and support frame  168  for several, weather protection segments, one of which is in partial presentation. Primaries  36  are mounted within E-channel assemblies  169  and center channels  175 . Short entry channel  176  is located at ramp entry  177 . Exit ramp  179  is shown at the opposite end of pathway  41  with centerline  42 . 
       FIG. 20  is a  FIG. 19  view circle enlarged detail showing the entry ramp  177  and short entry channel  176 . Top channel bezel is  159  is surrounding first primary LIM  36  in the asymmetrical pathway  160  holding E-channel  169  with anchor holes  156 . E-channel  169 , pathway  41  and ridable surface  32 , continues. Centerline  42  is shown on pathway  41  and ridable surface  32 . Window wall  162 , frame  168  and projection light  170  are shown. 
       FIG. 21  is a  FIG. 19  view circle enlarged detail showing the exit ramp  179 , centerline  42  and pathway anchoring holes  156  within asymmetrical pathway  160 . Shown is E-channel  169 , E-channel  175 , pathway  41  and ridable surface  32 , transitions to exit ramp  179 . 
       FIG. 22  is a  FIG. 19  view circle showing one of multiple shallow recess geometries  171 , in the pathway  41  to guide wheels in to the center channel  175  as it approaches the location of the pathway centerline  42  located LIM primary  36  in surrounding top channel bezel  159 , making it easier for the rider to center the bicycle&#39;s position and thus obtain the maximum thrust available from the completed LIM motor. 
       FIG. 23  is a cross-section of the asymmetrical pathway  160  with top channel bezel  159 , ridable surface  32  of pathway  41 , LIM primary  36 , power cable  37  and showing partial structural details  162  and  168 , with attached projection light  170 . 
       FIG. 24  is a  FIG. 23 , view circle detail, of asymmetrical pathway details, LIM primary  36  and power cable  37 . Bolts  154  fasten LIM support plate  151  and LIM primary base  152 . Top channel bezel  159  provides pathway  41  and ridable surface  32  continuity. E-channel assembly  175  is a long channel pathway support and  176  is a short channel pathway support. 
     Schematic Block Diagrams for Understanding Systems 
     The block schematics of  FIGS. 25 through 27 , relate functional elements of the system. 
       FIG. 25  is a schematic representation of a LIM primary  36  with electrically switchable polarity control of the magnetic traveling wave direction which induces current and a subsequent, interacting magnetic field force in a LIM secondary. 
       FIG. 26  is a block schematic of the mechanical relationships between LIM secondary  38 , LIM primary  36 , and pathway  41  with ridable surface  32 . 
       FIG. 27  is a block schematic of the power and control components for a LIM electrical system with pathway  41  and ridable surface  32  noted in relative position to LIM primaries  36 . 
     Operation of the LIM System and Method 
     The LIM design thrust, established between the interaction of LIM primary and LIM secondary, and dependent upon the slope of the pathway and the mass of the vehicle, is taken at a value that is gentle enough in acceleration so as to minimize any rearward body pitch tendency by the rider. The rider feels a thrust force at short time intervals in the forward travel mode at a chosen LIM primary spacing and design velocity, which is a function of LIM voltage and electrical current. The LIM secondary magnetic thrust, as developed, is applied at an extremely low geometric position, relative to the vehicle and rider center-of-gravity. In this manner, the transient thrust load is applied to the vehicle frame only in a forward horizontal direction, there being no other significant directional or out-of-plane forces imposed upon the bicycle. Forces that may occur, other than those propelling the bicycle forward, are uncoupled from the bicycle frame by the various attachment means whereby couplings are designed only to support those forward thrust forces. 
     Retardation Forces 
     LIM-controlled, polarity reversal at the primary coil assembly provides an additional, slowing process, as shown in  FIG. 25  if applied in downhill braking. The LIM secondary, rather than inducing a forward thrust force, as it traverses the LIM primary, may induce a controlled and softer, reversed, to the direction-of-travel, force which supplements the rider&#39;s hand brake, wheel rim braking action. 
     Conventional bicycle, wheel rim, braking systems are a rotating and translating mass that present a significant reduction in braking ability under wet road conditions with the manually controlled, wheel rim-friction braking devices attached to the bicycle frame. There is, therefore, the inherent, LIM-controlled capability to provide additional braking with a “soft” electro-magnetic force reversal, which may then provide a significant and increased additional element of safety in slowing or stopping the bicycle under wet weather and road conditions. 
     Other LIM Controls 
     Provision may be made for methods of switching the primary LIMs OFF and ON through the application of a software-driven logic network and sensor conditioning packages that maximize the throughput efficiency for multiple users of the system and also provide for the prevention of a condition that allows approaching the LIM primary from any but the correct direction, thus preventing an undesired, reversed magnetic thrust vector from occurring with an inadvertent wrong direction approach to the system by a rider. 
     Sudden Impact Load Handling 
     All LIM secondary embodiments, except those that are fixed, are retracted automatically with a sudden frontal impact load that releases the raising mechanism for the specified embodiment. 
     For example, this condition occurs upon accidental contact with road markers or other small obstructions. The attachment means, upon sudden aft loading of the LIM secondary, will retract the LIM secondary, upward, in the plane of the vehicle frame, to its stowed position, parallel to the ridable surface. This action does not result in any significant impulse loads being transferred to the rider-vehicle combination because of attachment design embodiments which minimize any tendency to destabilize the regular, dynamic forces on the bicycle. 
     Quick Attach and Detach Mode for the Secondary on the Bicycle 
     A quick release fastener  115  at the point of attachment to the frame of the bicycle, as shown in  FIG. 10 , permits quick detachment of the whole secondary assembly  38  should the user desire. A locking means, not shown, may be attached to the fastener and frame to minimize the potential for theft of the LIM secondary from the bicycle frame. 
     Other Possible Embodiments 
     While embodiments of the present invention have been illustrated and described, it will be apparent that other embodiments may be made without departing from the invention.