Abstract:
A folding bicycle presents a number of advantages over both conventional and other foldable bicycles. The folded size of 12 ×25×6 inches (305×635×153 millimeters) compares favorably to other folding bicycles, and its 11 lb. (eleven pound, or 5 kilogram mass) weight is significantly superior to even the closest lightweight model at eighteen pounds, and about half of the average portable bike weight of twenty-two pounds. The folded volume of the bike at 1800 square inches is slightly over one cubic foot. The portable bicycle has a folding stowage time of about 10 seconds, and a deployment time of about 6 seconds. A folding pedal and handle bar design contributes significantly to a folded lateral profile.

Description:
FIELD OF THE INVENTION 
   The present invention relates to improvements in the technology relating to personal transportation devices, and more particularly to folding bicycles which can fold to a position about the size of a purse or carry bag. 
   BACKGROUND OF THE INVENTION 
   Bicycles have been made and sold for over one hundred years. Folding bikes are known and tend to allow a bike to be folded into a smaller yet still bulky or cumbersome size. Furthermore the folding bike can be typically heavier than a non folding similar bike. The provision of a bike that folds into a package small enough to be carried in a general purpose rucksack and light enough to be carried great distances if needs be, has not been available to any practical extent. 
   In general, bicycles ranging from high performance sports uses to standard personal transportation devices, bicycles have generally had only one limitation -- the space occupied when the bicycle is not in use. Lightweight bicycles are known, but the size has continued to present a problem. One of the main size limitations has been the wheels. Most conventional bicycles have front and rear wheels which range from twenty six to twenty eight inches in diameter. Even ignoring the other structural aspects of the bicycle, the front and rear wheel alone represent the size of two large refuse container lids. 
   Existing folding bicycle products tend to fold in several actions, often leaving an oiled chain exposed on the outside, and other components of the bike protruding. As a result, conventional folding bicycles can be dirty and dangerous to users and their clothing. Generally the existing bikes tend to remain bulky, even when folded. 
   One reason that light portable bicycles are especially valuable is the increased need for personal transportation to “fill in” the gaps in the public transportation system. This is especially true for work situations where a commuter may drive to a train station and disembark from a train station which is several miles from work. Even a small portable bicycle would need to be specially stored in the workplace. Carriage of the small bicycle on the train presents an even more severe problem, especially on train lines having a “standing room only” level of crowding. Although some busses have bicycle racks, the racks are too few for the high number of bicycles which should be used. 
   Another needed “breakthrough” area is that of facilitating bicycle usage by persons with lesser upper body strength. This involves the need for lighter weight and more compact size. The average portable bicycle weighs about twenty-two pounds. Even with a carrying case or backpack, a twenty-two pound weight is a significant weight for a small individual lacking upper body strength. Given that most individuals also have other items to carry, the twenty-two pound average weight is an addition rather than a total carry weight. As such, weight prevents a significant portion of the population from deriving the advantages of portable bicycle use. 
   In terms of utilization of a bicycle, much of the total picture for increased utilization involves the ability to store the bicycle for occasional uses for times such as when all the busses and trains may not be running. In this case, more continuous workplace storage will need to be facilitated. In large metropolitan areas the office space available to workers continues to shrink. To be available as an “on demand” link, both storage and carriage will need to be facilitated. 
   SUMMARY OF THE INVENTION 
   A folding bicycle presents a number of advantages over both conventional and other foldable bicycles. The folded size of 12 ×25×6 inches (305×635×153 millimeters) compares favorably to other folding bicycles, and its 11 lb. (eleven pound, or 5 kilogram mass) weight is significantly superior to even the closest lightweight model at eighteen pounds, and about half of the average portable bike weight of twenty-two pounds. The folded volume of the bike at 1800 square inches is slightly over one cubic foot. The portable bicycle has a folding stowage time of about 10 seconds, and a deployment time of about 6 seconds. 
   A folding pedal design contributes significantly to a folded lateral profile. Once folding is complete, the package stays automatically locked together. A brake design is very different to a conventional bicycle system and utilizes a banded drum for positive braking and which eliminates the need for periodic adjustment seen in conventional brake system. 
   The pedal drive uses a power transmission system having a two stage chain drive with a freewheel mechanism located on the crank axle rather than the rear wheel axle. Externally, conventional reflectors are replaced with retro-reflective decals so that the reflectivity will be present and not subject to damage as would a conventional reflector structure. 
   The folding bicycle herein has pushed the envelope in both size and weight to correspondingly make the advantage of a folding bicycle even more advantageous. With increased usage of the bicycle, the risk of theft can be virtually eliminated, and it can readily be taken away on holidays or occasional excursions with a reduced consciousness of being specially taken along. Users will tend to make the folding bicycle a normally carried item in backpacks, automobiles, office filing cabinets, brief cases, boats, apartments, car boots, cupboards, and more. 
   The folding bicycle herein has only four parts which are un-clamped and folded, (1) the main frame, (2) the handlebar, (3) the saddle, and (4) the pedals. The folding bicycle herein includes a design which provide the user with a reasonably compact product that can be used in different environments. Furthermore, the folding bicycle herein has its internal mechanisms concealed to eliminate protruding elements which could injure the user or causing damage to the user&#39;s clothing or storage structures. The compact, self-contained streamlined folding bicycle allows the user to handle and the product without affecting the user&#39;s daily routines. The quick folding and unfolding procedure enables the user to avoid using any significant time in the folding/unfolding process. 
   In addition, the increased use of a folding bicycle would reduce security to a minimal level as the user could take the bike with them as apposed to leaving it outside, therefore reducing the possibility of theft or vandalism. The size would also allow the bike to be taken onto public transport without it intruding into other people&#39;s space and would be manageable to the user. 
   The resulting folded bicycle has no projections or loose parts, and the folded package is easy to handle. The saddle forms a natural handle for the folded stowed structure. The drive mechanism is completely enclosed, meaning that carpets and upholstery are not marked. No vulnerable parts are exposed to damage and, most importantly, the cable runs are fully protected. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which: 
       FIG. 1  is a perspective view of the folding bicycle in a deployed position; 
       FIG. 2  is a side view of the folding bicycle in  FIG. 1  and illustrating further details of construction; 
       FIG. 3  is a side view in accord with the view of  FIG. 2  and shown in a folded position at normal height; 
       FIG. 4  is a view in accord with the view of  FIG. 3  and shown in a partially lowered position with respect to the upper components and with the seat tube brought to a horizontal position; 
       FIG. 5  is a view in accord with the view of  FIG. 4  and shown with the seat brought slightly downward and with the front and rear telescoping tubes brought to a fully stowed position; 
       FIG. 6  is a view in accord with the view of  FIG. 5  and shown with the seat brought to a vertical, fully stowed position, and with the handle bar connection member turned rearwardly 180°; 
       FIG. 7  is a front view of the bicycle in accord with  FIG. 6  and illustrating the folding of handle and brake assemblies and pedals; 
       FIG. 8  is a side view of the fully folded bicycle shown in  FIG. 7 ; 
       FIG. 9  is an expanded view of the drive mechanism with the right side of the crankcase housing removed; 
       FIG. 10  is an expanded view of the braking and drive mechanism with the left side of the crankcase housing removed; 
       FIG. 11  is a schematic view of the brake system of the front telescoping tube and front wheel; and 
       FIG. 12  is a perspective view of a double channel slide block used with the front telescoping tube and front wheel brake system. 
   

    DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The description and operation of the invention will be best initiated with reference to  FIG. 1  which illustrates a side view of a folding bicycle  31  shown in its fully deployed position. Structures seen include a major triangular assemblage of structures including a collapsible triangular frame formed from a collapsible front steering tube assembly  33  that includes a telescopic inner tube  35  which telescopes with respect to a telescoping outer tube  37  and is secured by a quick release clamp  39 , and a locking button  41  seen through its aperture. The front steering tube assembly  33  is rotatable within a front steering joint  43 . Front steering joint  43  is flanked on its upper and lower sides by an upper fitting  45  and an expanded length lower fitting  47 . Below the lower fitting  47  is a fork  49  which engages a front wheel  51  and its axle bolt  53 . An abbreviated length fender  55  is seen. The lower fitting  47  is seen to have six reinforced areas which join two halves of the lower fitting  47  by bolting or riveting. 
   Pivotally attached to the front steering joint  43  is a forward pivoting strut  61  which is attached to the front steering joint  43  by a pair of opposing ear lugs, only one ear lug  63  is seen in  FIG. 1 . The other end of forward pivoting strut is connected to a center joint  65 . 
   Center joint  65  is in the form of a “U” shaped length of tubing with the side walls forming pivot ear lugs at points near one end where forward pivoting strut  61  pivotally connects to it. Center joint  65  will preferably have a locking button  66 , or an internal bolt latch to insure that it positively engages forward and rearward pivoting struts  61  and  67  to keep them in alignment while the bicycle  31  is deployed. The locking button may have an internal block which is urged against the flat ends of the forward and rearward pivoting struts  61  and  67  when they are in co-axial position. 
   Pivotally attached to the other end of the center joint  65  front steering joint  43  is a rearward pivoting strut  67  which is attached to the center joint  65  at its rear with the opposing side walls forming pivot ear lugs at points near the end opposite the connection to the forward pivoting strut  61 . The orientation of the center joint  65  is that it enables the forward and rearward struts  61  and  67  to open and lie in a collinear relationship in linear alignment with the center joint  65  during its deployed orientation. In folding, as will be seen, center joint  65  is attached to enable it to rise as the forward and rearward struts  61  and  67  pivot angularly down with respect to the center joint  65 . 
   The rearward most end of rearward strut  67  is attached into the upper portion of the crankcase housing  69  in an orientation that will enable rearward strut  67  to be angularly displaced upwardly with respect to the crankcase housing  69  on stowage. The crankcase housing  69  is attached to or around a collapsible rear tube assembly  71  which includes a rear telescopic inner tube  73  which telescopes with respect to a telescoping outer tube  75  and is secured by a quick release clamp  77 , and a locking button  79  seen through its aperture. 
   The crankcase housing  69  forms a fork-like attachment to a rear wheel  81 , along with a driven connection to be shown. On the right side of the crankcase housing  69  seen in  FIG. 1 , a flat removable housing cover  83  accommodates the internal driven connection. A rear fender  85  can also be seen. 
   Rearwardly adjacent the quick release clamp  77 , is a seat tube fitting  87  having ear lugs which pivotally engage a seat tube assembly  89  at the lower end of a telescopic outer tube  91 , about a pivot axis  92 . An inner tube  93  fits within the outer tube  91 . At the top of the outer tube  91 , a stay  95  is pivotally connected to a fitting  97  at the top end of the outer tube  91 . The fitting  97  does not slide, but is mounted to an exacting level on the outer tube  91 . The fitting  97  includes a release (on the side opposite that shown in  FIG. 1 ) to fix the upward and downward position of the inner tube  93  with regard to the outer tube  91  in order to set the height of a seat or saddle  99 . Saddle  99  has a forward central portion  101  and a pari of rearwardly extending ischial supports  103  which define an accommodation slot  105  therebetween. The ischial supports  103  support the rider and the area which would otherwise be occupied by the accommodation slot  105  is typically not utilized during seated riding. The accommodation slot  105  enables the saddle  99  to extend partially around the rear of the crankcase housing  69  during stowage in order to take up slightly less space. 
   The other end of the stay  95 , the stay  95  is pivotally connected to a double fitting  107  which defines a pair of pivot axes. A first pivot axis  109  exists between the double fitting  107  and the end of the stay  95 . A second pivot axis  111  exists between the double fitting  107  and the upper end of the rear telescopic inner tube  73 . As will be seen, this double fitting  107  provides an offset which will allow a parallel relationship of the outer tube  91  with respect to the telescoping outer tube  75 . The stay  95  has a general inverted “U” cross sectional shape both for increased strength, and to allow it to accommodate the telescopic outer tube  91  more closely adjacent the telescoping outer tube  75  in the folded stowage position. 
   The double fitting  107  is also mechanically connected to an upper steering joint member  113  having its other end connected to a steering pivot  115 . The double pivot enables the upper steering joint member  113  to pivot with respect to the rear telescopic inner tube  73 . The steering pivot  115  also includes an upper spacer  117  and lower spacer  119  which helps to define and offset the other relationships. Lower spacer  119  limited the extent to which the telescoping inner tube  35  can fit inside the telescoping outer tube  37 . 
   Atop the steering pivot  115  is a boss  121  in the shape of a cylinder and from which a handlebar connection member  123  extends and attaches to a main handle bar support  125  having a pair of oppositely oriented handlebar locking buttons  126  which, as will be shown, are used to enable elements of the handle bar structures to be folded. At each end of the main handle bar support  125  is a right handle and brake assembly  127  and a left handle and brake assembly  129 . 
   A control cable  131  from right handle and brake assembly  127  enters an aperture  135  in the main handle bar support  125 . A control cable  133  from left handle and brake assembly  129  simply leads back to the front part of the double fitting  107 , where cable  133  enters the rear telescopic inner tube  73 . As will be seen, the right handle and brake assembly  127  and left handle and brake assembly  129  are axially displaceable from the main handle bar support to a position where they may be folded to a horizontal position. 
   Also seen in  FIG. 1  is a right pedal crank  141  and right pedal  143 , as well as a left pedal crank  145  and left pedal  147 . The pedals  143  and  147  are shown in their unfolded, deployed position. Folding cab involve movement of the pedals  143  and  147  typically toward their respective pedal cranks  141  and  145 , to a position where they may be pivoted or folded in a position roughly parallel to the crank. Other mechanisms can be used to achieve folding pedals, including buttons, latches, and the like. The pedals  143  and  147  will have the stability not to unfold while the bicycle  31  is deployed and in use. 
   Referring to  FIG. 2 , the elements identified in  FIG. 1  can be more clearly seen. The shape of seat  99  and the spacing relationship of the first and second pivot axes  109  and  111  are seen. Both the spacing relationship of first and second pivot axes  109  and  111  and the size and shape of the stay  95  and tube  91  will permit a close parallel stowed relationship. 
   Referring to  FIG. 3 , the bicycle  31  is shown in a position where the steps necessary to fold it have been accomplished. The steps necessary to achieve the configuration shown in  FIG. 3  includes merely the actuation of the locking button  66  and the raising of the center joint  65  upwardly to cause the forward and rearward pivoting struts  61  and  67  to begin to angularly pivot toward a more parallel relationship with respect to their adjacent telescoping front outer tube  37  and rear outer tube  75 . It should be noted that while a user is riding the bicycle  31  that the resultant forces on the wheels  51  and  81  will act to keep the forward and rearward pivoting struts  61  and  67  in alignment, as well as the mechanism of the locking button  66 . 
   Note that the front quick release clamp  39  is slightly above the rear quick release clamp  77  and that the front wheel  51  is slightly above the rear wheel  81 . This configuration occurs when the “A” frame is folded in and before the height of the bicycle  31  is reduced. This illustrates that the center joint&#39;s double pivoting connection enables some upward and downward relative movement of the front telescoping outer tube  37  with respect to the rear telescoping outer tube  75 . 
   Referring to  FIG. 4 , it can be seen that the front quick release clamp  39  is now slightly below the rear quick release clamp  77  and that the front wheel  51  is level with the rear wheel  81 , and that the center joint  65  is also generally level wit the ground.  FIG. 4  especially illustrates that the locking buttons  41  and  79  have been pressed in to unlock the front telescoping inner tube  35  and rear telescoping inner tube  73  such that only their apertures can be seen, and that the quick release clamps  39  and  77  have been unlocked to allow the unlock the front telescoping inner tube  35  and rear telescoping inner tube  73  to telescopingly collapse into their respective front outer tube  37  and rear outer tube  75 . Note that as the rear telescopic inner tube  73  collapses with respect to the collapsible rear tube assembly  71  that more of the control cable  133  from left handle and brake assembly  129  will loop upwardly with respect to the top of the bicycle  31 . 
   The telescoping inner tubes  35  and  74  are shown only partially collapsed to emphasize the transition position of the telescoping outer seat tube  91 . At this middle position, note that the double fitting  107  has enabled pivot axis  109  to not only be rearwardly displaced with respect to pivot axis  111 , but that during the downward travel of the telescoping inner tubes  35  and  74  seen in  FIGS. 3 and 4 , that pivot axis  109  lies directly over and travels straight toward pivot axis  92 . 
   The seat telescoping outer tube  91  has reached a horizontal position and it may be that seat telescoping inner tube  93  may need to be slightly brought more telescopingly within seat telescoping outer tube  91  in cases where it is extended for taller riders, especially where the length of the outer tube  91  can accommodate a much longer extension of the inner tube  93  than is seen in  FIG. 4 . Note also that the fitting  97  does not move with respect to the outer tube  91  upon folded stowage. 
   Referring to  FIG. 5 , as has been mentioned, the stay  95  has an inverted “U” shape which is sufficient to partially cup or surround the seat outer tube  91 . Further, note that the pivot axis  109  of the double fitting  107  has covered over and is collinear with the pivot axis  92  of the seat tube fitting  87  (covered and by the pivot axis  109  and thus not seen). This enables both the stay  95  and the seat outer tube  91  to continue to pivot downwardly about a common pivot axis. This common pivot axis movement serves to further lock the telescoping inner tubes  35  and  74  in the stowed position with respect to the telescoping inner tubes  35  and  74 . 
   Quick release clamp  39  is shown in the open position and quick release clamp  77  is shown in the closed position. Locking the clamps  39  and  77  will further prevent any unintended deployment once the bicycle  31  is in the stowed position. Note the lower spacer  119  position with respect to the clamp  39 . The stabilized stowed position is achieved with wheels  51  and  81  level. 
   Referring to  FIG. 6 , the seat outer tube  91  is shown in a position of continued movement about the pivot axis  109  where the seat outer tube  91  is parallel to both the rear telescoping outer tube  75  and stay  95 . Note that the ischial supports  103  of the seat  99  are forward of the rearward most extent of the crankcase housing  69  due to the accommodation slot  105 . Again, the stay  95  is seen continuing to partially cup or surround the seat outer tube  91 . 
   Having achieved the position shown in  FIG. 6 , the next step in folding to stowage position is the turning of the main handle bar support  125  to a position 180° from that shown in  FIGS. 1–5 , so that the handle bar connection member  123  will lie rearwardly and over and generally parallel to the upper steering joint member  113 . Note that the extra length of the control cable  133  from left handle and brake assembly  129  will actually facilitate the turning of the main handle bar support  125  by providing enough of a length to gently loop. 
   In the deployed position, the front telescopic inner tube  35  is fixed with respect to the telescoping outer tube  37  both by engagement of the quick release clamp  39  and the interlocking of the locking button  41 . Both of these structures are engaged when the bicycle  31  is in the deployed position. Once the bicycle  31  is begun to be folded, the locking button  41  and the release clamp  39  are disengaged. This leaves relative rotational displacement possible between the front telescopic inner tube  35  and the main handle bar support  125  affixed to it, with respect to the telescoping outer tube  37 . 
   Thus the user simply rotates the main handle bar support 125 by 180° to place the main handle bar support  125  directly over the upper steering joint member  113 . Once the main handle bar support  125  directly over the upper steering joint member  113 , the quick release clamp can be re-engaged to fix the position of the main handle bar support  125 . However, the folding down of the saddle  99  and the locking into place of the quick release clamp  77  would be sufficient to maintain folded stability. Only the locking button  41  aperture is seen as the locking button is depressed, within the annular space between the forward telescopic inner tube  35  and telescoping outer tube  37 , and on the side opposite the aperture through which it locks. 
   Once the main handle bar support  125  and handlebar connection member  123  are directly over the upper steering joint member  113 , the handlebar structures are in a position to be further compactly folded. In  FIG. 1 , a pair of pair of oppositely oriented handlebar locking buttons  126  were seen on the main handle bar support  125 . Each one of the pair of oppositely oriented handlebar locking buttons  126  is associated with the right handle and brake assembly  127  and left handle and brake assembly  129  located underneath it. 
   Referring to  FIG. 7 , a front view of the bicycle  31  seen in the position shown in  FIG. 6  with the handlebar connection member  123  rotated rearward, is shown. The boss  121  is seen prominently, and the brake handles of the right handle and brake assembly  127  and left handle and brake assembly  129  (shown in dashed line format collinearly with the main handle bar support  125 , are seen to be pointed rearwardly. The arrows indicate that, after depression of the pair of oppositely oriented handlebar locking buttons  126 , the right and left handle and brake assemblies  127  and  129  are pulled axially outwardly until the fullest outward extent of movement is possible. 
   Each of the right and left handle and brake assemblies  127  and  129  are mounted within the main handle bar support  125  on a guide pins (not shown) so that they may be axially moved out of their respective end of the main handle bar support enough that only the pivoting action of the guide pins (not shown) hold them with respect to the main handle bar support  125 . The bottom portions of the ends of the main handle bar are removed to enable the right and left handle and brake assemblies  127  and  129  to fold down once they have moved to their outermost extent. 
   The solid line rendering of the right and left handle and brake assemblies  127  and  129  illustrate their having been pivoted downwardly to a position parallel with the front telescoping outer tube  37 . At the ends of the right and left handle and brake assemblies  127  and  129  closest to connection with the main handle bar support  125 , the freed, oppositely oriented handlebar locking buttons  126  can be seen. Upward rotation of the right and left handle and brake assemblies  127  and  129  will place oppositely oriented handlebar locking buttons  126  into a depressed position automatically as they are raised and they will not need to be depressed in order to re-enter the main handle bar support  125 . The re-engagement of the clamp  39  is suggested, but it can be seen that the vertically downward position of the right and left handle and brake assemblies  127  and  129  lend additional stability to prevent unintended rotation of the handlebar connection member  123  and main handle bar support  125 . 
   Also seen in  FIG. 7  are the folding of the right and left pedals  143  and  147 . Typically the unfolding may accomplished by a latch or by movement of the pedals slightly outwardly to an un-locked position and then folding toward the associated cranks  141  and  145 . Further, if a mechanism is utilized which will permit folding the pedals  143  and  147  only toward their respective cranks  141  and  145  and not away from them, a greater degree of stability during riding can be achieved. Folding the pedals  143  and  147  toward their respective cranks  141  and  145  creates roughly the same degree of horizontal compactness as the outermost extent of the upper vertically hanging right and left handle and brake assemblies  127  and  129 . 
     FIG. 7  and its solid line structures represents the full extent of folding of the bicycle  31 , and illustrates the lateral compactness achieved in the present inventive design. Referring to  FIG. 8 , a right side view similar to that seen in  FIGS. 4–6  gives a visual impression of the forward to rear compactness and height compactness of the bicycle  31 . As before, the bicycle  31 , in the states shown in  FIG. 8  has an overall dimension of 12×25×6 inches (305×635×153 millimeters). 
   Referring to  FIG. 9 , a closeup of the back half of the crankcase housing  69  taken from the perspective of the right side of the bicycle illustrates the mechanical internals of the crankcase. A crank axle  151  has a free wheeling clutch, including an inner clutch drive  153  immediately surrounding it. Inner clutch drive  153  is mechanically connected to an outer clutch drive  155  for rotation of the inner clutch drive  153  in one direction only. 
   Most typical bicycles locate the free wheeling clutch on the wheel axle. The free wheeling clutch is a disengagement between the crank axle  151  (and the cranks  141  and  145 ) for times when the driven wheel  81  is spinning faster than the crank axle  151 . This enables the bicycle  31  to coast down hill without corresponding forward mechanical movement of the crank axle  151 , and cranks  141  and  145 . 
   Outer clutch drive  155  is mechanically connected to a main sprocket  157 . Main sprocket  157  has a chain  159  (shown schematically) connected to an axle sprocket  161  attached to an axle  163 . As can be seen by comparing  FIG. 9  to  FIGS. 4 and 5 , the flat removable housing cover  83  (in addition to the right side half of the crankcase housing  69  upon which crankcase housing  69  fits) completely isolates the chain  159  from any possible contact with the user. Chain contact is a major source of soiled and destroyed clothing, and can cause accidents. Both the wheels  51  and  81  are preferably made of a solid polymeric material and thus the need for servicing or any reason to open the crankcase housing  69  should be largely eliminated. 
   Details of engagement of the lower end of the rear telescoping outer tube  75  are seen. An engagement structure  171  contacts and bears against the rear telescoping outer tube  75  and has a lower member  173  to engage structures in the left half of the crankcase housing  69  shown. Also exposed is an ear lug  181  which lies just inside an opening the crankcase housing  69  seen in  FIG. 1 . Ear lug  181  enables the rearward pivoting strut  67  to move angularly from the deployed position seen in  FIG. 1  to the foldably stowed position seen in  FIG. 8 . 
   Referring to  FIG. 10  a view oppositely oriented with respect to  FIG. 9  is taken against the right half of the crankcase housing  69  and its attached flat removable housing cover  83 . This view illustrates the terminal portions of a braking system. A shielded cable  191  emanates from an aperture or slot in the lower member  173 . The cable may include a bracket  193  which is preferably attaches the outer shielding of the shielded cable  191  to the removed left half of the crankcase housing  69  in order to stabilize and control the end of the shielded cable  191 . 
   The shielded portion of the shielded cable  191  is seen to extend slightly beyond the bracket  193 , and then terminate. At the termination, an inner wire core  195  extends from the end of the shielding in a direction tangential to a brake drum  197 , then surrounding the brake drum  197 , and terminating at a bracket  199 . 
   Like bracket  193 , the bracket  199  appears to float, but is in fact attached to the left half of the crankcase housing  69  which has been removed to reveal the components of the brake system. Both the brackets  193  and  199  are used to control the angle and resting position of the inner wire core  195  as it surrounds the brake drum  197 . It is important that during non-brake operation of the bicycle  31  that the inner wire core  195  enable friction free movement of the brake drum  197 . The brackets  193  and  199  control of the angle of approach around both sides of the brake drum  197  achieve this. 
   Note that with regard to  FIG. 10 , the normal forward motion of the bicycle  31  occurs from right to left and that the wheel  81  turns counterclockwise. Tightening of the inner wire core  195  by withdrawing it into the shielded portion of the shielded cable  191  will produce a pulling of the inner wire core  195  against the bracket  199 . The brake drum  197  then somewhat frictionally moves against the inner wire core  195  in a way to very slightly tighten it further against the bracket  199 . 
   If the direction of movement were reversed, the friction of the brake drum  197  would tend to pull the inner wire core  195  away from the termination of the shielding of the shielded cable  191  can tend to counteract the force used to withdraw the inner wire core  195  and weaken the braking from the standpoint of the user. Thus, the configuration shown enhances the manual pressure used to affect braking while using brackets to control the angularity and degree of approach of the inner wire core  195  with respect to the brake drum  197 . So long as the inner wire core  195  is effectively spring loaded to return to a rest position with sufficient slack, the non-brake operation should be effectively friction-free. 
   Referring to  FIG. 11 , a schematic drawing of one possible realization for the braking system for the front wheel  51  is shown. Whereas the rear wheel  81  included a shielded cable which increasingly protrudes from the double fitting  107 , the braking system for the front wheel  51  doesn&#39;t have the protrusion action but rather includes a different method to achieve collapsibility. Typically, the left handle and brake assembly  129  is used to brake the front tire  51 . 
   As can be seen with the larger detail, the left handle and brake assembly  129  includes a handle  201  and a brake assembly  203  mounted thereon. Brake assembly  203  includes an attachment fitting  205  and a lever  207  which is set to pivot with respect to the attachment fitting  205 . Typically the lever  207  will include a spring (not shown) which will urge the lever  207  away from the handle  201  and into a position in which it is shown unless a user manually actuates it. The springs typically used are coil springs surrounding a pivot point  209  between the lever  207  and brake assembly  203 . 
   A first length of raw cable  211  is positioned with respect to a shielded cable  213  so that movement of the lever  207  will pull the first length of raw cable  211  through the shielded portion. The short length of shielded cable  213  terminates at a plate  217  so that movement of the first length of raw cable  211  beyond the extent of the plate  217  will pull the raw cable  211  toward the plate  217 . 
   Plate  17  or its equivalent can be introduced anywhere above the lower spacer  119  and such that any movement of the telescopic inner tube  35  with respect to the telescoping outer tube  37  will not interfere with the first length of raw cable  211 . In the example of the inventive bicycle  31 , the plate  217  or similar structure can be placed at the handlebar connection member  123 , boss  121  or main handle bar support  125 , or even within the telescopic inner tube  35 . 
   Telescopic inner tube  35  is shown schematically with respect to the telescoping outer tube  37 . The other surrounding structures are simply not shown so that the clarity of action can be emphasized. The first length of raw cable  211  extends through a double channel slide block  221 . Referring to  FIG. 12 , the double channel slide block  221  is a small unitary volume of material having a pair of bores, including first bore  223  and second bore  225 . The first and second bores should be made of sufficient diameter that both the first length of raw cable  211  and a second length of raw cable  231  can slide through easily, but not so large that termination beads can enter, jam or pass through. 
   The main idea for double channel slide block  221  is that any slack in the first or second lengths of raw cable  211  or  231  will result in at least one of them sliding through the double channel slide block  221  to relieve bunching. Without the double channel slide block  221 , a single length of raw cable would at best be forced to spiral about the inside of the telescopic inner tube  35  or the telescoping outer tube  37 , or pinched at their junction. 
   The first length of raw cable  211  is shown extending through bore  225  of the double channel slide block  221  and terminates at a termination bead  235  at the outside of the other end of the through bore  225 . Second length of raw cable  231  is shown extending through bore  223  of the double channel slide block  221  in the other direction and terminates at a termination bead  239  at the outside of the other end of the through bore  223 . 
   Beyond the double channel slide block  221  , the second length of raw cable  231  is shown extending through bore  223  of the double channel slide block  221  and through the bottom of the front telescoping outer tube  37 . An optional fixed length of raw cable channel  241  or some other physical path directing device can be used to position the remaining structures with respect to a brake drum  243 . 
   The other structures may include the continuation of the raw cable about the brake drum  243 , or a fitting  245  may be provided to make length adjustments with respect to a specialized band  247 . The band  247  (or cable) may be fixed with respect to a bracket  249 . The direction of normal forward motion of the brake drum  243  is shown in either direction to emphasize that the front wheel may be made to turn in a direction which might mitigate the force applied by the lever  207 . This may depend upon the other mechanics employed in the front brake system. 
   The operation of the schematic of  FIG. 11  is as follows. Once folding of the bicycle  31  begins, the telescopic inner tube  35  will begin to move downward with respect to the telescoping outer tube  37 . The first length of raw cable  211  will move toward the second length of raw cable  231 . Because the termination beads  235  and  239  move away from the double channel slide block  221 , both the first and second lengths of raw cable  211  and  231  can slide past each other within the double channel slide block  221 . 
   If the double channel slide block  221  is made of metal, and if the bicycle  31  is foldably stowed in a position where the telescopic inner tube  35  and telescoping outer tube  37  are vertical, it is likely that the double channel slide block  221  will move downward with the raw cable  211  as the second length of raw cable  231  will move through the bore  223  and upward toward the plate  217 . Thus, even where one cable predominantly moves through the double channel slide block  221  while the other may remain fixed through gravity or the like, the double channel slide block  221  will act as a guide for the other cable. In any event, the double channel slide block  221  helps to organize and direct the first and second raw cables  211  and  231  with respect to each other. 
   Upon re-deployment and unfolding of the bicycle  31 , the tensile force link between the first and second raw cables  211  and  231  will automatically be re-established. It should be noted that upon deployment, the locking button  41  will re-engage only upon a full extension of the telescopic inner tube  35  with respect to the telescoping outer tube  37 , and therefore the relative lengths of the tubes  35  and  37  will be the same each time the bicycle  31  is deployed. As such, multiple deployments and foldable stowage operations will not upset the exactitude of the connection between the first and second lengths of raw cable  211  and  231 . 
   While the present invention has been described in terms of a portable folding bicycle, &amp; more particularly to a particular set of mechanical structures which exhibit maximum compactness, ease of deployability and stowage and light weight, the mechanisms disclosed can be applied to other devices. 
   Although the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art.