Abstract:
The inventive device includes a tricycle frame comprising a front wheel steering mechanism, the left and right trailing arms with folding mechanism, the left and right rear wheel brake systems, and a cambering mechanism. The improvements have been made to the construction and operation of cambering mechanism, the trailing arm folding and locking mechanism and the handlebar. It provides better maneuverability and stability during cambering maneuver, easier operation of folding, and quick assembly and disassembly of a one-piece handlebar. This is achieved through an original cambering mechanism with a rocking-bar connecting spherical bearings and a polymer energy-storing element, and an original, easy to operate and anti-disengagement sleeve-type folding mechanism, and a one-piece steering handlebar with quick handlebar locking mechanism.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The application claims the benefit of PPA Ser. No. 60/549,960 filed on Mar. 4, 2004 by the present inventor 

   FEDERALLY SPONSORED RESEARCH 
   Not Applicable 
   SEQUENCE LISTING OR PROGRAM 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The present invention relates generally to a three wheel cambering vehicle and more specifically it relates to a cambering vehicle with a rocking-bar cambering mechanism and trailing arm folding mechanism, for providing better maneuverability and stability during cambering maneuver, and for easier operation of folding. better maneuverability and stability are achieved through an original cambering mechanism with a rocking-bar connecting spherical bearings and polymer energy-storing element. The easier operation of folding is achieved through an original, easy to operate and anti-disengagement sleeve-type folding mechanism. The invention also uses a one-piece steering handlebar and a quick handlebar locking mechanism to improve the robustness of the steering, and easiness of assembly. 
   2. Description of the Related Art 
   It can be appreciated that three wheel cambering vehicles have been in use for years. Typically, three wheel cambering vehicles are comprised of a steerable front wheel controlled by a steering handlebar (just as for a regular bicycle); a pair of rear wheels on mounted on the two trailing arms; two foot pedals on the trailing arms; two brakes on the rear wheels; a trailing arm folding and locking mechanism to make the vehicle portable; and a cambering mechanism which interconnects the steering column and two trailing arms. 
   The main problems of conventional three wheel cambering vehicles are commonly with the cambering mechanism. The cambering mechanism for the vehicles patented in U.S. Pat. Nos. 6,220,612 &amp; 6,499,751 (Cambering vehicle and mechanism), U.S. Pat. No. 6,467,781 (Tricycle), U.S. Pat. No. 6,517,093 (Foldable tricycle), and U.S. Pat. No. 6,554,302 (Tricycle operated by torsion thereof) are based on the same principle. It has a freely rotating yoke in the middle, whose ends are connected with the polymer donuts on the two trailing arms. With this design, when the vehicle tilts, the yoke deforms the polymer donuts. The two polymer donuts serve both as the connection elements and as the energy storing element (spring). When the rider of the vehicle tilts his or her body to the inside of the turn to perform cambering maneuver, the polymer donut on the trailing arm at the inner side of the turn is deformed easily by the body weight. But, the deformation of the donut on the trailing arm at the opposite side relies on the push of the foot. If the foot fails to push enough to deform the polymer donut, the wheel at the outer side of the turn has the tendency to lift off the ground. It is especially so for deeply tilted turns. The lift of the wheel makes the motion unstable and may cause the maneuver to be out of control. The root cause of the situation is two independent energy-storing element. Actually, this double polymer-donut design also makes tilting rigid, especially for children or for sharp turn maneuvers. 
   The second common problem with conventional three wheel cambering vehicles is that their folding mechanisms aren&#39;t easy to use, since they all use finger pressure. Pins are always jammed due to the nature of the folding mechanism. It&#39;s difficult to apply adequate finger pressure, especially for children. 
   Another problem with conventional three wheel cambering vehicles is that they either have a two-piece steering handlebar design, which is not robust, or they have a one-piece handlebar design but the assembly and disassembly are not convenient. This convenience is important since the portability of the vehicle relies on it. 
   While these devices may be suitable for the particular purpose to which they are intended, there are limits and inconveniences as described above. It is highly beneficial to improve the design to achieve better maneuverability and stability during cambering maneuver, easier operation of folding, and robustness of a one-piece quick assembly and disassembly handlebar. In these respects, the cambering vehicle with rocking-bar cambering mechanism according to the present invention substantially departs from the conventional concepts and designs of the prior art. In so doing, the present invention provides an apparatus primarily developed for the purpose of providing better maneuverability and stability during cambering maneuver, easier operation of folding, and robustness of a one-piece quick assembly and disassembly handlebar. The invention presented here achieves these through an original cambering mechanism with a rocking-bar connecting spherical bearings and a polymer energy-storing element, an original, easy to operate and anti-disengagement sleeve-type folding mechanism, and a one-piece steering handlebar with a quick handlebar locking mechanism. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing disadvantages inherent in the known types of three wheel cambering vehicles now present in the prior art, the present invention provides a new cambering vehicle construction wherein new structures are utilized. The new construction provides better maneuverability and stability during cambering maneuver, easier operation of folding, and robustness of a one-piece quick assembly and disassembly handlebar. This is achieved through an original cambering mechanism with a rocking-bar connecting spherical bearings and a polymer energy-storing element, an original, easy to operate and anti-disengagement sleeve-type folding mechanism, and a one-piece steering handlebar with a quick handlebar locking mechanism. 
   The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new cambering vehicle with rocking-bar cambering mechanism that has many of the advantages of the three wheel cambering vehicle mentioned heretofore. The present invention contains many novel features that result in a new cambering vehicle with rocking-bar cambering mechanism, anti-disengagement sleeve-type folding mechanism, and a one-piece steering handlebar with a quick handlebar locking mechanism, and which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art three wheel cambering vehicle, either alone or in any combination thereof. 
   To attain this, the present invention generally comprises a tricycle frame with a front wheel steering mechanism, two trailing arms and two rear wheel brakes; a novel rocking-bar cambering mechanism; an novel anti-disengaging sleeve-based folding mechanism for folding trailing arms; and a novel one-piece handlebar clamping mechanism. As shown in  FIG. 1 , the front wheel steering mechanism comprises handlebar  2 , steering shaft  5 , steering shaft housing  6 , steering column  7 , front wheel mounting fork  10 , and front wheel  11 . The right and left trailing arms, respectively  13  and  17 , are structures with their one end connected to the cambering linkage  8  and  9  accordingly. The other end of the trailing arms  13  and  17  are attached with foot pedals  14  and  18 , and rear wheels  15  and  19 . The brake system comprises brake handles  3  mounted on the handlebar  2 , and brake lines and brake shoes. As shown in  FIG. 2 , the rocking-bar cambering mechanism basically comprises a front mounting block  23 , a front pivot pin  24 , two cambering linkage  8  and  9 , right and left respectively, two spherical bearings  35  and  31 , two bearing cushions  36  and  30 , a central mounting block  33 , a cylindrical polymer energy storing element (polymer spring)  34 , and a rocking-bar  32 . As shown in  FIG. 3 , the anti-disengaging sleeve-based folding mechanism comprises pivot pin  51 , locking sleeve  12 , locking spring  52 , cylindrical locking fork  53 , anti-disengaging plunger  55  and plunger spring  54 . As shown in  FIG. 4 , the handlebar locking mechanism comprises fixed half-moon  1 , movable half-moon  62 , pivot pin  61 , locking lever  63 , locking pin  64 , tie rod  65  and tie nut  60 . 
   There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter. 
   In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. 
   A primary object of the present invention is to provide a cambering vehicle with rocking-bar cambering mechanism, anti-disengagement sleeve-type folding mechanism, a one-piece steering handlebar with a quick handlebar locking mechanism that will overcome the shortcomings of the prior art devices. 
   An object of the present invention is to provide the cambering vehicle with better maneuverability and stability during cambering. This is achieved through an original cambering mechanism design using spherical bearings, a polymer energy storing element and a rocking-bar. 
   Another object is to provide the cambering with better flexibility during turning maneuver. 
   Another object is to provide the cambering vehicle with a better folding mechanism. Instead of using finger pressure, the new mechanism uses a hold-and-pull of sleeve. This is much easier than using finger pressure. The new mechanism also prevents the accidental disengage of the sleeve. 
   Another object is to provide the cambering vehicle with a one-piece quick assembly and disassembly steering handlebar. 
   Another object is to provide the cambering vehicle with only one (instead of two as with the prior arts) energy-storing element (polymer spring). This will allow the engineer to have more flexibility when choose this “polymer spring” in both structural forms and spring parameters. 
   To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact that the drawings are illustrative only, and that changes may be made in the specific construction illustrated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings wherein: 
       FIG. 1  is a side perspective view of the vehicle showing its general tricycle framework and interconnections of main components. 
       FIG. 2  is a section view of the cambering mechanism showing the main components and structure of this mechanism. 
       FIG. 3  is sectioned side view of the sleeve folding mechanism showing all the main components and structure. The trailing arm is shown both at folded and at extended positions; and the locking sleeve is shown both at locked and released positions. 
       FIG. 4  is a structural and operation sequence view of handlebar locking mechanism. From left to right is the sequence of unlocking and removing the handlebar from the clamp. 
       FIG. 5  illustrates the operation principle of the cambering mechanism showing the “rocking” of the rocking-bar and the deformation of polymer element. 
       FIG. 6  shows a variation in construction of the cambering mechanism. The polymer energy storing element takes the form of a disk with a hole in the center where the rocking-bar is fitted. 
       FIG. 7  shows another variation in construction of the cambering mechanism. A third spherical bearing is mounted inside the central mounting block and the polymer energy storing element takes the form of two pieces of cylindrical donuts. 
       FIG. 8  shows another variation in construction of the cambering mechanism. The two spherical bearing, that the two ends of the rocking-bar are connected, are mounted inside the cambering linkages without cushions. 
       FIG. 9  illustrates the operation principle of the cambering mechanism for the variation in construction shown in  FIG. 6   
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Turning now descriptively to the drawings, the attached figures illustrate a cambering vehicle with rocking-bar cambering mechanism, anti-disengagement sleeve-type folding mechanism, a one-piece steering handlebar with a quick handlebar locking mechanism. The cambering vehicle comprises a tricycle frame with a front wheel steering mechanism, two trailing arms and two rear wheel brakes; a novel rocking-bar cambering mechanism; a novel anti-disengaging sleeve-based folding mechanism for folding trailing arms; and a novel handlebar clamping mechanism. As shown in  FIG. 1 , the front wheel steering mechanism comprises handlebar  2 , steering shaft  5 , steering shaft housing  6 , steering column  7 , front wheel mounting fork  10 , and front wheel  11 . The right and left trailing arms, respectively  13  and  17 , are structures with their one end connected to the cambering linkage  8  and  9  accordingly. The other end of the trailing arms  13  and  17  are attached with foot pedals  14  and  18 , and rear wheels  15  and  19 . The brake system comprises brake handles  3  mounted on the handlebar  2 , brake lines and brake shoes. As shown in  FIG. 2 , the rocking-bar cambering mechanism basically comprises a front mounting block  23 , a front pivot pin  24 , two cambering linkage  8  and  9 , right and left respectively, two spherical bearings  35  and  31 , two bearing cushions  36  and  30 , a central mounting block  33 , a cylindrical polymer energy storing element (polymer spring)  34 , and a rocking-bar  32 . As shown in  FIG. 3 , the anti-disengaging sleeve-type folding mechanism comprises pivot pin  51 , locking sleeve  12 , locking spring  52 , cylindrical locking fork  53 , anti-disengaging plunger  55  and plunger spring  54 . As shown in  FIG. 4 , the handlebar locking mechanism comprises fixed half-moon  1 , movable half-moon  62 , pivot pin  61 , locking lever  63 , locking pin  64 , tie rod  65  and tie nut  60 . 
   As shown in  FIG. 1 , the front wheel steering mechanism comprises handlebar  2 , steering shaft  5 , steering shaft housing  6 , steering column  7 , front wheel mounting fork  10 , and front wheel  11 . The upper end of the steering shaft  5  is connected with the fixed half-moon  1  of the handlebar clamp, and the other end of the steering shaft  5  is inside the steering shaft housing  6 , which is used for height adjustment. Near the lower end of the steering column  7  attached the front mounting block  23  and central mounting block  33 . These two mounting blocks are part of the cambering mechanism. The front-wheel mounting fork has an upside down “U” shaped structure. 
   The right and left trailing arms, respectively  13  and  17 , are structures with their one end connected to the cambering linkage  8  and  9  accordingly, and the other end of the trailing arms  13  and  17  are attached with foot pedals  14  and  18 , and rear wheels  15  and  19 . The left and right trailing arms  13  and  17  have identical construction, and the left trailing arm  13  is used as example for illustration here. The base structure of the left trailing arm  13  is a bent tube. The cylindrical locking fork  53  is attached at its one end, and foot pedal  14  and rear wheel  15  are at the other end, as shown in  FIG. 1 . The front end of the cylindrical locking fork  53  is connected to the cambering linkage  8  through pivot pin  51 . The trailing arm is folded around this pivot pin. 
   The brake system comprises brake handles  3  mounted on the handlebar  2 , brake lines and brake shoes. The brake lines run along the steering shaft  5 , steering shaft housing  6 , steering column  7 , trailing arms  13  and  17 , to reach the brake shoes underneath foot pedal  14  and  18  respectively. 
   As shown in  FIG. 2 , the rocking-bar cambering mechanism basically comprises a front mounting block  23 , a front pivot pin  24 , two cambering linkage  8  and  9 , right and left respectively, two spherical bearings  35  and  31 , two bearing cushions  36  and  30 , a central mounting block  33 , a cylindrical polymer energy storing element (polymer spring)  34 , and a rocking-bar  32 . 
   There are possible construction variations to the cambering mechanism described above. The spherical bearing cushions could be made of materials different from polymer, or even no cushions at all. The polymer spring could be a mechanical spring. Or, when the polymer spring is used, it could have a different form than a cylindrical one. The “spring” here means an element that deforms and stores and releases energy during cambering.  FIG. 6 ,  FIG. 7  and  FIG. 8  show some of the construction variations, disk shaped polymer springs and no cushions to the spherical bearings, structural element  66 , such as a bearing, embedded in the central mounting block. The deformation of the polymer springs of these variations is also shown. 
     FIG. 2 ,  FIG. 6 ,  FIG. 7  and  FIG. 8  show the detailed structures of the mechanism and construction variations. Cambering vehicle uses tilting (cambering) of the vehicle to move forward in a sinusoidal path. The tilting of a regular tricycle without cambering mechanism will result in one of its rear wheels lifting off from the ground. Cambering mechanism is to provide extra “degree of freedom” to facilitating tilting that maintains all three wheels stay on the ground. As shown in the figure, Front mounting block  23  and central mounting block  33  are both attached to the outside of steering column  7 , front pivot pin  24  connects the left cambering linkage  8  and the right cambering linkage  9  together through front mounting block  23 . On the other side, two spherical bearings  35  and  31  are mounted in the bearing recesses on the polymer bearing cushions  36  and  30 . The cushions are mounted in the housing on the two cambering linkage  8  and  9 . The inner diameters of the bearings  35  and  31  are mounted on the rocking-bar  32 . The rocking-bar is wrapped with the polymer spring  34 , and the polymer spring  34  is secured by central mounting block  33 . 
   As shown in  FIG. 1 ,  FIG. 2  and  FIG. 5 , when the vehicle does the tilting (cambering), two trailing arms  13  and  17  will pivot around the front pivot pin  24 . The pivoting will change positions of the two spherical bearings  35  and  31 . They move in the opposite direction with equal amount of displacement. The drawing on the first row from top in  FIG. 5  shows the neutral position of the polymer spring (in the case of a cylindrical design of polymer spring), i.e. when the vehicle is not tilted. As shown, there is no deformation to the polymer spring  34 .  FIG. 9  shows the case when the design of the polymer spring is in the form of a disk,  40 . However, cambering changes the relation of the two bearings  35  and  31  with respective to central mounting block  33 , this change will cause rocking-bar  32  to rotate with respective to the central mounting block  33  and deform polymer spring  34  or  40 . This deformation creates a restoring force to restore the vehicle to its neutral position.  FIG. 5  and  FIG. 9  show some of the detail of this process. The deeper the tilting, the bigger the deformation and thus the bigger the restoring force. In this cambering mechanism, the restoring force is only by the polymer element  34  or  40 . The spherical bearings are free joints, so the two trailing arms  13  and  17  don&#39;t have independent restoring force to overcome. With this rocking-bar mechanism, body weight overcomes the center polymer restoring force, and that&#39;s the only restoring force. (In the case of independent restoring forces on individual trailing arms, as with designs of prior arts discussed previously, the shifted body weight over comes only one of the restoring forces, the situation is especially true with deep tilting). 
   As shown in  FIG. 3 , the anti-disengaging sleeve-type folding mechanism comprises pivot pin  51 , locking sleeve  12 , locking spring  52 , cylindrical locking fork  53 , anti-disengaging plunger  55  and plunger spring  54 . The folding mechanism on the left and right trailing arms are identical, so the left is used as the example for illustration here. The cylindrical fork  53  is attached to the trailing arm tube  13  at its rear end, and connected to the cambering linkage  8  through pivot pin  51 . This is the pivot pin around which the trailing arm  13  is folded for convenience of storage. The end of the cambering linkage  8  is designed with notches and steps that it mates with the locking sleeve  12  in both folded and extended position, as shown in  FIG. 3 . The end of this cambering linkage  8  is also designed with a step to mate with the cylindrical locking fork  53  in the extended position to make the connection more robust. The details are shown in  FIG. 3 . The cylindrical locking fork  53  has a hole on its cylindrical wall for mounting of the anti-disengaging plunger  55 , the plunger locked into a hole on the locking sleeve  12  in the extended position of the trailing arm to prevent the sleeve from disengaging. Spring  52  is used to push locking sleeve into engaging with the end of cambering linkage  8 , it&#39;s covered inside the sleeve, for hiding pinch point and for better appearance. 
   As shown in  FIG. 4 , the handlebar locking mechanism comprises fixed half-moon  1 , movable half-moon  62 , pivot pin  61 , locking lever  63 , locking pin  64 , tie rod  65  and tie nut  60 . The fixed half-moon  1  is attached to the upper end of steering shaft. Movable upper half-moon  62  is connected to it through pivot pin  61 . When moveable upper half-moon  62  turns to open as shown in the  FIG. 4 , it allows the handlebar  2  to be placed into or removed out of the clamp. Clamping lever  63  has a cam surface designed around its pivot hole  64  for applying clamping force. The lower end of the tie rod  65  is threaded, and nut  60  is attached at its end when clamping, as shown in the figure. 
   The rider of this vehicle operates it by standing atop on the left and right foot pedal  14  and  18 , gripping onto the handlebar  2 . The rider then pushes off with one foot, and quickly put this foot on the foot pedal. Then, with this initial motion, the rider starts to turn the vehicle with both a turning of the handlebar  2  and tilting of the vehicle. This tilting is executed by coordinated body-weight shifting and steering shaft tilting, toward the inside of the turn. The above-described maneuver is continued in the opposite direction, and the vehicle moves in a sinusoidal path. 
   The basic principle of this motion is well known. The above cambering maneuver converts body height changes into rotational inertial momentum. The rider propels the vehicle through body shifting. 
   To fold the trailing arm for storage (again, take only the left trailing arm as an example for illustration), the anti-disengaging plunger  55  is depressed and locking sleeve  12  is pulled all the way rearward. After the trailing arm is at 90 degree from its expended working position, the wall of lock sleeve  12  will lock into mating notch on the cambering linkage  8 , thus keeps the trailing at this position until released by pull the lock  12  again. To remove handlebar  2  from the clamp for compact storage, follow the procedure illustrated in  FIG. 4 , and do the reverse to put it back. 
   As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided. 
   With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
   Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.