Abstract:
An adult tricycle has a front frame and a rear frame that are pivotally connected together and a suspension for minimizing shock as the tricycle is driven over a surface. The suspension includes a shock absorbing element having a leading end that is pivotally connected with the front frame and a trailing end that is pivotally connected with the rear frame. The tricycle has a front wheel with a diameter that is bigger than the diameters of the rear wheels and a seat that sits higher than the diameter of the front wheel. The adult sized tricycle enables parents to ride cycles with small children and provides a safe, stable cycle for mature adults and senior citizens.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present patent application claims benefit of U.S. Provisional Application No. 62/211,466, filed Aug. 28, 2015, and U.S. Provisional Application No. 62/111,332, filed Feb. 3, 2015, the disclosure of which is hereby incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Parents love to engage in outdoor, physical activities with their children including playing sports, roller skating and bicycle riding. One of the greatest joys in life is when a parent and a child ride bicycles together in the neighborhood or at a local park. 
         [0003]    Often, a parent may desire to ride along with a young child as the latter rides his or her tricycle or small bicycle. In many instances, due to the size of the child and the size of the cycle, a child rides his or her tricycle or small bicycle at a very slow speed, which makes it difficult for the adult to maintain balance on an adult-sized bicycle designed to travel at higher speeds. This leads to frustration and disappointment for both the parent and the child because they cannot easily and comfortably ride together on their respective cycles. 
         [0004]    In addition, mature adults and senior citizens are often apprehensive to ride conventional bicycles because it becomes more and more difficult for adults to maintain their balance on bicycles as they age. 
         [0005]    Thus, there is a need for an adult-sized tricycle that enables a fully grown adult to ride slowly next to his or her child, as the child rides his or her own tricycle or small bicycle. There also remains a need for an adult-sized tricycle that is able to handle the weight of a fully grown adult and that has enhanced stability and comfort. Moreover, there remains a need for an adult-sized tricycle that is easy to transport, ship, and store. In addition, there remains a need for an adult sized tricycle that provides a smooth, comfortable ride for adults of all ages. 
       SUMMARY OF THE INVENTION 
       [0006]    In one embodiment, the present application discloses an adult-sized tricycle that enables a fully grown adult parent to ride slowly next to his child, as the child rides his or her own tricycle or small bicycle. 
         [0007]    In one embodiment, the present application discloses an adult-sized tricycle having a foldable frame so that the adult sized tricycle can be collapsed for transport, shipping and/or storage. In one embodiment, the frame may be broken down into smaller parts. 
         [0008]    In one embodiment, an adult-sized tricycle has a suspension coupled to the frame to provide for a more comfortable ride and minimize shock as the tricycle is driven over a surface. In one embodiment, the adult tricycle preferably has a front frame and a rear frame that are pivotally connected together. The suspension desirably includes a shock absorbing element having a leading end that is pivotally connected with the front frame and a trailing end that is pivotally connected with the rear frame. In one embodiment, the tricycle has a passenger seat that is mounted to the rear frame for enabling a passenger to ride behind the driver&#39;s seat. 
         [0009]    In one embodiment, an adult tricycle has a front wheel and two rear wheels. Two pedals are connected with the front wheel for advancing the adult tricycle in a forward direction only. In one embodiment, the pedals may be used to rotate the front wheel in a forward direction, however, the pedals may not be used to rotate the front wheel in a reverse direction. In one embodiment, when the front wheel is rotating in a forward direction, the pedals may be held stationary and the front wheel may continue for rotate in the forward direction. In one embodiment, the front wheel includes a freewheel mechanism that allows the front wheel to turn at a rate of rotation that is different and/or faster than the pedals. If a freewheel mechanism were not provided on the front wheel of the adult tricycle, a simple ride could be exhausting, because a rider could never stop pumping the pedals. In addition, going downhill could be very dangerous because the pedals would turn with the front wheel at a much faster rate than an adult rider could keep up with. 
         [0010]    In one embodiment, an adult tricycle includes a front frame having a leading end and a trailing end, a rear frame having a leading end and a trailing end, and a pivot connection that pivotally connects the trailing end of the front frame with the leading end of the rear frame. The front and rear frames may be made of metal. In one embodiment, a suspension system couples the front and rear frames together for dampening pivoting movement of the front and rear frames relative to one another. In one embodiment, the adult tricycle has a front wheel mounted on the leading end of the front frame, and a pair of rear wheels rotatably mounted on the trailing end of the rear frame. A seat is mounted to an upper end of the front frame. In one embodiment, the front and rear wheels are adapted to ride over a riding surface, whereby the distance between the seat and the riding surface is greater than the diameter of the front wheel. 
         [0011]    In one embodiment, the diameter of the front wheel is at least 1.5 times greater than the diameter of each of the rear wheels. In one embodiment, the diameter of the front wheel is about 20 inches, each of the rear wheels has a diameter of about 10-12 inches, and the distance between the seat and the riding surface is about 27-29 inches. 
         [0012]    In one embodiment, the suspension system includes a shock absorber including a spring and a telescoping shaft having a longitudinal shaft that controls compression of the shock absorber along the longitudinal axis of the telescoping shaft. In one embodiment, the shock absorber has a leading end pivotally coupled with the trailing end of the front frame and a trailing end pivotally coupled with the leading end of the rear frame. 
         [0013]    In one embodiment, the front frame includes a rigid Y-shaped structure having a horizontally-extending first section, a sloping second section, and a seat bar that is connected with trailing ends of the horizontally-extending first section and the sloping second section. 
         [0014]    In one embodiment, the rear frame includes first and second rigid loop-shaped parts, a laterally extending support bar that interconnects leading ends of the first and second rigid loop-shaped parts, and a top plate that interconnects upper portions of the first and second rigid loop-shaped parts. 
         [0015]    In one embodiment, an adult tricycle includes a front frame having a leading end and a trailing end, the trailing end of the front frame including a seat bar having an upper end and a lower end, a seat mounted on the upper end of the seat bar, a rear frame having a leading end and a trailing end, and a pivot connection located adjacent the lower end of the seat bar for pivotally connecting the trailing end of the front frame with the leading end of the rear frame. 
         [0016]    In one embodiment, the adult tricycle includes a suspension system having a leading end pivotally connected with the seat bar of the front frame and a trailing end pivotally connected with the rear frame for dampening pivoting movement of the front and rear frames relative to one another. 
         [0017]    In one embodiment, a front wheel is rotatably mounted on the leading end of the front frame and a pair of pedals is coupled with the front wheel. In one embodiment the front wheel has a freewheel mechanism that enables the front wheel to rotate faster than the pair of pedals. In one embodiment, the pedals may be pumped to move forward, however, the pedals are incapable of being pumped to move the adult tricycle in a rearward direction. 
         [0018]    In one embodiment, a pair of rear wheels is rotatably mounted on the trailing end of the rear frame and the rear wheels are free to rotate relative to the rear frame. In one embodiment, the front wheel has a diameter that is at least 1.5 times greater than the diameters of the respective rear wheels. The front and rear wheels may be pneumatic rubber tires that are filled with air, or may be made of plastic or polymers. 
         [0019]    In one embodiment, the suspension system includes a shock absorber having a spring and a telescoping shaft with a longitudinal shaft that controls compression of the shock absorber along the longitudinal axis of the telescoping shaft. In one embodiment, a leading end of the longitudinal shaft is pivotally connected with a midsection of the seat bar, which is located between the upper and lower ends of the seat bar. 
         [0020]    In one embodiment, the rear frame includes two rigid loop-shaped parts that are laterally space from one another, each of the rigid loop-shaped part having a leading end and a trailing end. In one embodiment, a first laterally extending support, such as a bar, interconnects the leading ends of the two rigid loop-shaped parts, and a second laterally extending support, such as a plate, interconnects upper sections of the two rigid loop-shaped parts. In one embodiment, a double rear axle is connected with the trailing ends of the two rigid loop-shaped parts, whereby the rear wheels are rotatable mounted on outer ends of the double rear axle. 
         [0021]    In one embodiment, the double rear axle includes a first axle bar extending laterally at the trailing end of the rear frame, a second axle bar extending laterally at the trailing end of the rear frame, a first stabilizer plate connected with the first and second axle bars, and a second stabilizer plate spaced from the first stabilizer plate and being connected with the first and second axle bars. In one embodiment, the first stabilizer plate is connected with the trailing end of a first one of the two rigid loop-shaped parts, and the second stabilizer plate is connected with the trailing end of a second one of the two rigid loop-shaped parts. 
         [0022]    In one embodiment, an adult tricycle includes a pair of handle bars coupled with the front wheel for steering the adult tricycle. In one embodiment, a hand brake is attached to one of the handle bars for applying a braking force upon the front wheel. 
         [0023]    In one embodiment, an adult tricycle includes a front frame having a leading end and a trailing end, the front frame including a seat bar and a seat mounted on an upper end of the seat bar, a rear frame having a leading end and a trailing end, and a pivot connection located adjacent a lower end of the seat bar for pivotally connecting the trailing end of the front frame with the leading end of the rear frame. In one embodiment, the adult tricycle includes a suspension system having a leading end pivotally connected with the seat bar and a trailing end pivotally connected with the rear frame for dampening pivoting movement of the front and rear frames relative to one another. 
         [0024]    In one embodiment, the adult tricycle includes a front wheel mounted on the leading end of the front frame and a pair of pedals coupled with the front wheel, whereby the front wheel has a freewheel mechanism that enables the front wheel to rotate faster than the pair of pedals. In one embodiment, the adult tricycle includes a pair of rear wheels rotatably mounted on the trailing end of the rear frame and which are free to rotate relative to the rear frame. In one embodiment, the front and rear wheels are adapted to travel over a riding surface. In one embodiment, the front wheel has a diameter that is greater than the diameters of the rear wheels, and the distance between the seat and the riding surface is greater than the diameter of the front wheel. 
         [0025]    These and other preferred embodiments of the present invention will be described in more detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0026]      FIG. 1  shows a side view of an adult tricycle having a front frame and a rear frame pivotally connected together, in accordance with one embodiment of the present invention. 
           [0027]      FIG. 2  shows a rear perspective view of the adult tricycle shown in  FIG. 1 . 
           [0028]      FIG. 3  shows a side view of the front frame of the adult tricycle shown in  FIGS. 1 and 2 . 
           [0029]      FIG. 4  shows a front view of the adult tricycle shown in  FIGS. 1 and 2 . 
           [0030]      FIG. 5  shows another front view of the adult tricycle shown in  FIG. 4 . 
           [0031]      FIG. 6  shows a side view of the rear frame of the adult tricycle shown in  FIGS. 1 and 2 . 
           [0032]      FIG. 7  shows a side view of a mid-section of the adult tricycle shown in  FIGS. 1 and 2 . 
           [0033]      FIG. 8  shows a rear perspective view of the mid-section of the adult tricycle shown in  FIG. 7 . 
           [0034]      FIG. 9  shows a rear view of the adult tricycle shown in  FIGS. 1 and 2 . 
           [0035]      FIG. 10  shows a bottom view of the rear frame of the adult tricycle shown in  FIG. 6 . 
           [0036]      FIG. 11  shows another bottom view of the rear frame of the adult tricycle shown in  FIGS. 6 and 10 . 
           [0037]      FIG. 12  shows a bottom view of the adult tricycle shown in  FIG. 11  including the rear frame, a rear axle housing encasing the rear axle, and a junction box used for connecting the rear frame with the rear axle housing, in accordance with one embodiment of the present invention. 
           [0038]      FIG. 13  shows a perspective view of the rear frame, the rear axle, and the junction box shown in  FIG. 12 . 
           [0039]      FIG. 14  shows a side view of the rear frame, the rear axle housing, and the junction box shown in  FIG. 13 . 
           [0040]      FIG. 15  shows a side view of a partially assembled adult tricycle before a front frame and a rear frame are assembled together, in accordance with one embodiment of the present invention. 
           [0041]      FIGS. 16A and 16B  show a locking assembly used for connecting a shock absorbing element with a rear frame of an adult tricycle, in accordance with one embodiment of the present invention. 
           [0042]      FIG. 17  shows a side view of an adult tricycle including the locking assembly of  FIGS. 16A and 16B  connecting a shock absorbing element with the rear frame of an adult tricycle. 
           [0043]      FIGS. 18A and 18B  show a split collar locking assembly used for pivotally connecting a front frame of an adult tricycle to a rear frame of the adult tricycle, in accordance with one embodiment of the present invention. 
           [0044]      FIGS. 19A and 19B  show a method of assembling the split collar locking assembly of  FIGS. 18A and 18B , in accordance with one embodiment of the present invention. 
           [0045]      FIGS. 20 and 21  show the split collar locking assembly pivotally connecting front and rear frames of an adult tricycle, in accordance with one embodiment of the present invention. 
           [0046]      FIG. 22  shows an adult tricycle having a triple tree frame structure for limiting turning of a front wheel, in accordance with one embodiment of the present invention. 
           [0047]      FIGS. 23A-23C  shows an adult tricycle having a front frame and a rear frame pivotally connected together, and a suspension coupling the front and rear frames, in accordance with another embodiment of the present invention. 
           [0048]      FIGS. 24A-24B  show an adult tricycle having a front frame and a rear frame pivotally connected together, and a suspension coupling the front and rear frames, in accordance with yet another embodiment of the present invention 
       
    
    
     DETAILED DESCRIPTION 
       [0049]    Referring to  FIGS. 1 and 2 , in one embodiment, an adult tricycle  30  preferably includes a front frame  32  and a rear frame  34  that are connected together at a mid-section  36 . In one embodiment, the front and rear frames are pivotally connected together. The front and rear frames may be disassembled from one another for packaging/shipment/transport, and later assembled together upon reaching a desired location. In one embodiment, the front frame  32  preferably includes a front fork  38 , a front wheel  40  connected to a lower end of the front fork  38 , and handle bars  42 A,  42 B connected with the front wheel  40  for steering the adult tricycle. 
         [0050]    The adult tricycle  30  desirably has pedals  44 A,  44 B connected with the front wheel  40 . The pedals  44  may be cranked (e.g., using the driver&#39;s feet) for rotating the front wheel  40  in a forward direction designated R 1 . The pedals  44  are designed to “free-wheel” relative to a rotating front wheel. Thus, when the front wheel  40  is rotating and a rider stops pedaling, the pedals  44  will remain stationary as the front wheel  40  continues to rotate in the direction R 1 . In one embodiment, the pedals  44  may only be used to advance the adult tricycle  30  in a forward direction, and the pedals  44  may not be used to back-up the adult tricycle in a rear direction that is opposite the forward direction. In one embodiment, the pedals may be used to go in both the forward and reverse directions. 
         [0051]    In one embodiment, the front frame  32  has a Y-shape including a horizontally-extending first section  46  and a sloping second section  48 . A rider seat  50  is preferably secured to a trailing end of the horizontally-extending first section  46 . A trailing end of the sloping second section  48  of the front frame  32  is desirably pivotally connected with a leading end of the rear frame  34  (e.g., pivotally connected) as will be described in more detail herein. 
         [0052]    In one embodiment, the rear frame  34  of the adult tricycle  30  desirably has a triangular shape. A passenger seat  52  may be mounted on the rear frame  34  and located behind the rider seat  50 . A pair of passenger foot rests  54 A,  54 A project laterally from opposite sides of the trailing end of the sloping second section  48  of the rear frame  34 . 
         [0053]    The adult tricycle  30  desirably includes a rear axle  56  that is connected with a trailing end of the rear frame  34 . The rear axle  56  preferably has outer ends, and first and second rear wheels  58 A,  58 B are rotatably secured to the respective outer ends of the rear axle  56 . 
         [0054]    In one embodiment, the front wheel  40  has a diameter of about 18-22 inches and more preferably about 20 inches. In one embodiment, the front wheel  40  is made of rubber having a width of about 2-3 inches and more preferably about 2.5 inches. In one embodiment, the rubber front wheel is filled with air. In one embodiment, the rears wheels  58 A,  58 B have a diameter of about 10-14 inches and more preferably about 13 inches, and a width of about 7-9 inches and more preferably about 8 inches. In one embodiment, the rear wheels are made of plastic or polymer material. In one embodiment, the rear wheels are made of rubber and are filled with air. 
         [0055]    In one embodiment, when the adult tricycle is placed upon a surface for riding, the seating surface of the seat  50  has a height of about 25-30 inches above the ground and more preferably about 27-29 inches above the ground. In one embodiment, the height of the seat  50  may be adjusted. In one embodiment, the front wheel  40  has a greater diameter than the rear wheels  58 A,  58 B and the seat  50  sits higher than the diameter of the front wheel. The height of the seat  50  (i.e., 25-30 inches above the ground), makes it easier for adults to mount and dismount the adult tricycle. 
         [0056]    Referring to  FIGS. 3-5 , in one embodiment, the adult tricycle  30  has a hand brake  60  that is mounted on the right handle bar  42 B. The hand brake  60  is preferably coupled with brake calipers  62  mounted adjacent the front wheel  40 . In order to brake, a rider may squeeze the hand brake  60 , which, in turn, closes the brake calipers  62  onto the rim of the front wheel  40  for stopping the adult tricycle. 
         [0057]    Referring to  FIG. 4 , the front frame  32  includes the fork  38  having lower ends that extend over opposite sides of the front wheel  40 . A vertically extending bar  64  at the leading end of the front frame  32  and the fork  38  forms a triple tree structure that limits how far the front wheel  40  may be turned to the left and to the right. When the front wheel  40  is turned fully to the left, the left fork  38 A contacts the front frame to function as a hard stop to limit the extent of turning to the left. When the front wheel  40  is turned fully to the right, the right fork  38 B contacts the front frame to function as a hard stop to limit the extent of turning to the right. 
         [0058]    Referring to  FIG. 6 , in one embodiment, the rear frame  34  has a triangular shape when viewed from the side including a top section  66 , a bottom section  68 , and a vertically extending section  70  that interconnects the leading ends of the top section  66  and the bottom section  68 . In one embodiment, the rears ends of the top and bottom sections  66 ,  68  are connected together to form the triangular shaped structure described above. The passenger seat  52  is mounted to the top section  66  of the rear frame  34 . In one embodiment, the passenger seat is designed to seat a child directly behind an adult who is driving the adult tricycle. As a result, a child and a parent/adult may ride and play together. 
         [0059]    Referring to  FIGS. 7 and 8 , in one embodiment, the front and rear frames  32 ,  34  are connected together at a mid-section of the adult tricycle  30 . The front and rear frames  32 ,  34  are desirably pivotally connected together and include a shock absorbing element that dampens bumps and jolts as a driver rides the adult tricycle. 
         [0060]    In one embodiment, the front frame  32  includes a support buttress  72  that extends between the horizontally-extending first section  46  and the sloping second section  48  of the front frame. The adult tricycle  30  preferably includes a shock absorbing element  74  having a leading end that is pivotally connected with the support buttress  72  and a trailing end that is pivotally connected with the upper end of the vertically extending section  70  of the rear frame  34 . In one embodiment, the shock absorbing element  74  desirably includes a spring  76  and a telescoping shaft  78  that controls compression of the shock absorbing element along the longitudinal axis of the telescoping shaft  78 . 
         [0061]    In one embodiment, the trailing end of the sloping second section  48  of the front frame  32  is desirably pivotally connected with the rear frame  34 , at a location that is adjacent the lower end of the vertically extending section  70  of the rear frame  34 . In one embodiment, a split locking collar  80  may be used for forming the pivotal connection between the front frame  32  and the rear frame  34 . 
         [0062]    Referring to  FIG. 9 , in one embodiment, the passenger seat  52  is mounted onto the top section  66  of the rear frame  34 . The passenger seat  52  is desirably located behind the driver seat  50  and is preferably aligned with the driver seat along the length of the adult tricycle  30 . 
         [0063]    Referring to  FIGS. 9-11 , the rear axle  56  is connected with the trailing end of the rear frame  34 . The rear axle  56  extends laterally along the rear of the tricycle and first and second rear wheels  58 A,  58 B are rotatably mounted to the respective outer ends of the rear axle  56 . 
         [0064]    Referring to  FIGS. 11-14 , in one embodiment, a stabilizer  82  is utilized for interconnecting the rear frame  34  with the rear axle  56  and maximizing torsional stability between the rear frame and the rear axle. In one embodiment, a mounting plate  84  is welded to the rear axle  56 . The trailing ends of the upper and lower sections  66 ,  68  of the rear frame  34  are split and the stabilizer  82  is positioned between the split trailing ends. The mounting plate  84  is secured to the bottom surface of the stabilizer  82  using a threaded fastener and a locking bolt  86 . The stabilizer  82  has a pair of laterally extending bores formed therein (not shown). A first bolt is passed through the first laterally extending bore and a second bolt is passed through the second laterally extending bore. The outer ends of the first and second bolts have threads. Locking nuts are fastened onto the ends of the first and second bolts for securing the split trailing ends of the upper and lower sections  66 ,  68  of the rear frame  34  to the stabilizer  82 . 
         [0065]    Referring to  FIG. 15 , the adult tricycle  30  preferably has two parts, the front frame  32  and the rear frame  34 , that may be assembled together. Providing two parts for the tricycle may make it easier to package, ship and/or transport the tricycle. In one embodiment, the tricycle is packaged in two separate parts, which facilitates shipping and/or transporting the tricycle. When a final destination is reached (e.g., a retail establishment, a home), the front and rear frames  32 ,  34  may be assemble together. 
         [0066]    In one embodiment, a sloping section  48  of the front frame has a trailing end including a bearing  90  with a laterally extending opening  92  passing through the bearing  90 . The leading end of the rear frame  34  preferably has a pair of spaced apart mounting flanges  94 A,  94 B, each mounting flange having an opening extending therethrough. 
         [0067]    Referring to  FIGS. 16A and 16B , in one embodiment, a split locking bolt  96  is used for pivotally securing the shock absorbing element  74  ( FIG. 7 ) with the rear frame ( FIG. 15 ). The split locking bolt  96  includes a female part  98  having an elongated cylindrical shaft  100  with an internally threaded female opening  102  at a first end and a shoulder  104  at an opposite, second end. The diameter of the shoulder  104  is larger than the diameter of the elongated cylindrical shaft  100 . The split locking bolt  96  preferably includes a male part  106  having an externally threaded shaft  108  and a shoulder  110  opposite the externally threaded shaft  108 . In order to assembled the female part  98  and the male part  106  together, the threaded shaft  108  is preferably inserted into the internally threaded female opening  102  and tightened until the shoulder  110  on the male part abuts against the free end of the elongated cylindrical shaft  100 . When the male and female parts are assembled together, the shoulders  104 ,  110  bound the ends of the elongated cylindrical shaft  100 . 
         [0068]    Referring to  FIG. 17 , in one embodiment, the split locking bolt  96  ( FIGS. 16A, 16B ) is passed through the openings of the mounting flanges  94 A,  94 B of the rear frame  34  for pivotally connecting the trailing end of the shock absorbing element  74  with the mounting flanges of the rear frame, which, in turn, pivotally connects the trailing end of the shock absorbing element with the rear frame  34 . 
         [0069]    Referring to  FIGS. 18A-18B , the split locking collar  80  ( FIGS. 7 and 8 ) preferably includes a first part  112  having a cylindrical shaft  114  with a reduced diameter section  115 , an internally threaded female opening  116  at a first end, and a shoulder  118  at an opposite, second end. The split locking collar  80  preferably includes a second part  120  having a cylindrical shaft  122  having a non-threaded female opening  124  at a first end and a shoulder  126  at an opposite second end. The split locking collar  80  desirably includes a threaded fastener  128  having a threaded shaft  130  and a head  132  with an Allen wrench depression formed therein. The reduced diameter section  115  of the first part  112  is preferably smaller than the inner diameter of the female opening  124  of the second part so that the reduced diameter section  115  of the first part  112  can slide into the female opening  124  of the second part  120 . 
         [0070]      FIG. 19A  shows the split locking collar  80  after the first and second parts  112 ,  120  have been assembled together. Referring to  FIGS. 19A and 19B , the threaded fastener  128  is then inserted into an opening at the shoulder end of the second part  120  so that the threads  130  may mesh with the female threads of the first part for locking the first and second parts  112 ,  120  together. The respective shafts  114 ,  122  preferably have the same outer diameter. The shoulders  118 ,  126  have larger diameters than the diameters of the shafts  114 ,  122 . 
         [0071]    Referring to  FIGS. 20 and 21 , in one embodiment, the front frame  32  of the adult tricycle  30  is pivotally connected with the rear frame  34  of the adult tricycle by positioning the bearing  90  at the trailing end of the sloping section  48  of the front frame  32  between the spaced attachment flanges  94 A,  94 B at the leading end of the rear frame  34 . The openings in the spaced attachment flanges  94 A,  94 B are preferably aligned with the elongated opening that passes through the bearing  90 . The first and second parts  112 ,  120  of the split locking collar  80  are inserted into the openings at the opposite ends of the elongated opening extending through the bearing  90 . The shoulder  118  of the first part  112  of the split locking collar preferably sits within a ring shaped depression formed in the outer surface of the first attachment flange  94 A. The opposing shoulder  126  ( FIG. 19B ) sits is a ring shaped depression (not shown) formed in the second attachment flange  94 B. The threaded fastener  128  ( FIG. 19A ) is then utilized for locking the first and second parts  112 ,  120  of the split locking collar together. 
         [0072]      FIG. 21  shows the split locking collar  80  inserted into the elongated bore  90 . The split locking collar has an internally threaded female opening. The threaded fastener is threaded into the internally threaded female opening to locking the first and second parts of the split locking collar together. 
         [0073]    Although the present invention is not limited by any particular theory of operation, it is believed that the split locking collar  80  shown and described herein effectively pivotally couples the front frame and the rear frame together while controlling and minimizing torsional and twisting movement of the front and rear frames relative to one another. The front and rears frames are free to pivot relative to one another over the cylindrical shafts  114 ,  122  of the split locking collar  80 , while the shoulders  118 ,  126  of the split locking collar clamp the respective attachment flanges  94 A,  94 B onto the ends of the elongated bearing  90  to minimize twisting and/or torsional movement of the front and rear frames  32 ,  34  relative to one another. 
         [0074]      FIG. 22  shows the front wheel  40  turned fully to the left. The left front fork  38 A engages the sloping section  48  of the front frame  32  to limit how far the front wheel may be turned to the left. The triple tree structure provides left and right limits on how far the front wheel  40  may be turned to the left and to the right. 
         [0075]    Referring to  FIGS. 23A-23C , in one embodiment, an adult tricycle  230  preferably includes a front frame  232  and a rear frame  234  that are connected together at a mid-section  236 . In one embodiment, the front and rear frames are pivotally connected together at a pivot point, as will be described in more detail herein. The front and rear frames may be disassembled from one another for packaging/shipment/transport, and later assembled together upon reaching a desired location. The front and rear frames may also be folded and/or collapsed together for packaging, shipment and/or transport. 
         [0076]    Referring to  FIGS. 23A and 23B , in one embodiment, the front frame  232  preferably includes a front fork  238 , a front wheel  240  connected to a lower end of the front fork  238 , and handle bars  242 A,  242 B connected with the front wheel  240  for steering the adult tricycle. 
         [0077]    The adult tricycle  230  desirably has pedals  244 A,  244 B connected with the front wheel  240 . The pedals  244 A,  244 B may be cranked (e.g., using the driver&#39;s feet) for rotating the front wheel  240  in a forward direction designated R 1 . In one embodiment, the pedals  244 A,  244 B are designed to “free-wheel” relative to a rotating front wheel so that when the front wheel  240  is rotating and a rider stops pedaling, the pedals  244 A,  244 B will remain stationary as the front wheel  240  continues to rotate in the direction R 1 . 
         [0078]    In one embodiment, the front frame  232  has a rigid Y-shape configuration including a horizontally-extending first section  246 , a sloping second section  248 , and a seat bar  249  that interconnects the trailing ends of the respective horizontally-extending first section  246  and sloping second section  248 . In one embodiment, a rider seat  250  is preferably secured to an upper end of the seat bar  249 . A trailing end of the sloping second section  248  of the front frame  232  is desirably pivotally connected with a leading end of the rear frame  234  (e.g., pivotally connected), as will be described in more detail herein. 
         [0079]    Referring to  FIGS. 23A-23C , in one embodiment, the rear frame  234  of the adult tricycle  230  desirably has a pair of rigid loops  265 A,  265 B that are joined together by cross support members as will be described in more detail herein. 
         [0080]    In one embodiment, the adult tricycle  230  desirably includes a double rear axle  256  that is connected with a trailing end of the rear frame  234 . The double rear axle  256  preferably has outer ends, and first and second rear wheels  258 A,  258 B are rotatably secured to the respective outer ends of the double rear axle  256 . In one embodiment, the rears wheels  258 A,  258 B have a diameter of about 10-12 inches, and a width of about 2-4 inches and more preferably about 3.0 inches. In one embodiment, the rear wheels  258 A,  258 B are made of rubber and are filled with air. 
         [0081]    Referring to  FIGS. 23A and 23B , in one embodiment, the front wheel  240  has a diameter of about 18-22 inches and more preferably about 20 inches. In one embodiment, the front wheel  240  is made of rubber having a width of about 2-3 inches and more preferably about 2.5 inches. In one embodiment, the rubber front wheel is filled with air. 
         [0082]    Referring to  FIG. 23B , in one embodiment, when the adult tricycle  230  is placed upon a road surface for riding, the seating surface of the seat  250  has a height H 1  of about 25-30 inches above the ground and more preferably about 27-29 inches above the ground. In one embodiment, the height of the seat  250  may be adjusted up or down or to the front or the rear. In one embodiment, the front wheel  240  has a greater diameter than the rear wheels  258 A,  258 B and the seat  250  sits higher than the diameter of the front wheel. The height of the seat  250  (i.e., 25-30 inches above the ground), makes it easier for adults to mount and dismount the adult tricycle. 
         [0083]    Referring to  FIGS. 23A and 23B , in one embodiment, the adult tricycle  230  has a hand brake  260  that is mounted on the right handle bar  242 B. The hand brake  260  is preferably coupled with brake calipers  262  mounted adjacent the front wheel  240 . In order to brake, a rider may squeeze the hand brake  260 , which, in turn, closes the brake calipers  262  onto the rim of the front wheel  240  for stopping the adult tricycle. 
         [0084]    Referring to  FIG. 23A , in one embodiment, the front frame  232  includes the fork  238  having lower ends that extend over opposite sides of the front wheel  240 . A vertically extending bar  264  at the leading end of the front frame  232  and the fork  238  forms a triple tree structure that limits how far the front wheel  240  may be turned to the left and to the right. When the front wheel  240  is turned fully to the left, the left fork  238 A contacts the front frame to function as a hard stop to limit the extent of turning to the left. When the front wheel  240  is turned fully to the right, the right fork  238 B contacts the front frame to function as a hard stop to limit the extent of turning to the right. 
         [0085]    Referring to  FIGS. 23A-23C , in one embodiment, the rear frame  234  has two rigid loop-shaped parts  265 A,  265 B that are joined together by cross support members. In one embodiment, the first rigid loop-shaped part  265 A includes a top frame section  266 A and a bottom frame section  268 A, and the second rigid loop-shaped part  265 B includes a top frame section  266 B and a bottom frame section  268 B. A laterally extending support bar  270  interconnects the leading ends of first and second rigid loop-shaped parts  265 A,  265 B. A top support plate  271  interconnects the top frame sections  266 A,  266 B of the respective rigid loop-shaped parts  265 A,  265 B. 
         [0086]    In one embodiment, the front and rear frames  232 ,  234  of the adult tricycle  230  are connected together at a mid-section  236  of the adult tricycle. The front and rear frames  232 ,  234  are desirably pivotally connected together and include a shock absorbing element, such as a spring, that dampens bumps and jolts as a driver rides the adult tricycle, and that controls pivoting movement of the front and rear frames relative to one another. 
         [0087]    In one embodiment, the front frame  232  includes a support buttress  272  that is connected to the trailing side of the seat bar  249  of the front frame. The adult tricycle  230  preferably includes a shock absorbing element  274  having a leading end that is pivotally connected with the support buttress  272  and a trailing end that is pivotally connected with the top support plate  271  of the rear frame  234 . In one embodiment, the shock absorbing element  274  desirably includes a spring  276  and a telescoping shaft  278  that controls compression of the shock absorbing element along the longitudinal axis of the telescoping shaft  278 . 
         [0088]    In one embodiment, the trailing end of the sloping second section  248  of the front frame  232  is pivotally connected with a leading end of the rear frame  234 , at a location that is adjacent the lower end of the seat bar  249  of the front frame  232 . In one embodiment, a split locking collar  280 , as described above in  FIGS. 18A-21 , may be used for forming the pivotal connection between the front frame  232  and the rear frame  234 . 
         [0089]    In one embodiment, the double rear axle  256  is connected with the trailing end of the rear frame  234 . The double rear axle  256  includes a first axle bar  257 A and a second axle bar  257 B that extend laterally across the rear of the adult tricycle  230 . The first and second rear wheels  258 A,  258 B are rotatably mounted to the respective outer ends of the double rear axle  256 . 
         [0090]    Referring to  FIGS. 23A and 23C , in one embodiment, two vertically-extending stabilizer plates  282 A,  282 B are utilized for interconnecting the first axle bar  257 A and the second axle bar  257 B for maximizing torsional stability between the first and second axle bars. In one embodiment, the stabilizer plates  282 A,  282 B are welded to the first and second axle bars  257 A,  257 B. The trailing ends of the rigid loop-shaped parts  265 A,  265 B are spaced from one another with the trailing end of the first rigid loop-shaped part  265 A secured to the first stabilizer plate  282 A and the trailing end of the second rigid loop-shaped part  265 B secured to the second stabilizer plate  282 B. Securing elements such as threaded fasteners and nuts may be utilized for securing the trailing end of the rear frame  234  with the stabilizer plates  282 A,  282 B of the double rear axle  256 . 
         [0091]    In one embodiment, the double rear axle  256  has a structure that provides improved weight distribution and torsional strength. The double rear axle having the two axle bars  257 A,  257 B buttressed by the stabilizer plates  282 A,  282 B provides greater strength and flexibility than can be attained when using a single bar for the rear axle. 
         [0092]    In one embodiment, the adult tricycle  230  preferably has two parts, the front frame  232  and the rear frame  234 , which may be assembled together. Providing two parts for the adult tricycle may make it easier to package, ship and/or transport the tricycle. In one embodiment, the adult tricycle is packaged in two separate parts, which facilitates shipping and/or transporting the tricycle. When a final destination is reached (e.g., a retail establishment, a home), the front and rear frames  232 ,  234  may be assemble together. 
         [0093]    Referring to  FIGS. 23A-23C , in one embodiment, the sloping section  248  of the front frame  232  has a trailing end including a bearing  290  with a laterally extending opening passing through the bearing  290 . The leading end of the rear frame  234  preferably has a pair of spaced apart mounting flanges  294 A,  294 B, each mounting flange having an opening extending therethrough. 
         [0094]    In one embodiment, a split locking bolt  296  is used for pivotally securing the shock absorbing element  274  with the plate  271  of the rear frame  234 . The split locking bolt  296  is similar to that described above in  FIGS. 16A-16B . 
         [0095]    Referring to  FIGS. 24A-24B , in one embodiment, an adult tricycle  330  is similar to that described above in  FIGS. 23A-23C . The adult tricycle  330  has a seat  350  with a back support  351  secured to the trailing end of the seat  350 . 
         [0096]    In understanding the functional and clinical relevance to exercise utilizing the adult tricycle disclosed herein, it is necessary to differentiate between closed chain exercise and open chain exercises. Closed chain exercising occurs when the foot is fixed on a surface. Open chain exercising occurs when the foot swings freely during exercise. The benefit of closed chain lower extremity exercise includes reduced sheer stress on the knee. The adult tricycle disclosed herein provides for closed chain exercising, which provides for an increase in quadriceps muscle force production with minimal amount of sheer force produced on the knee. Quadriceps muscle force (knee extensors) production increases as the knee is extended from 90 degrees to 30 degrees. The adult tricycle disclosed herein provides this full knee range of motion in a closed chain exercise position. In addition, the adult tricycle disclosed herein provides safety and stability on a three wheeled cycle, which allows mature adults and senior citizens to be able to ride a cycle that provides enhanced stability over standard bicycles 
         [0097]    The headings used herein are for organizational purposes only and are not meant to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. 
         [0098]    While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. For example, the present invention contemplates that any of the features shown in any of the embodiments described herein may be incorporated with any of the features shown in any of the other embodiments described herein and still fall within the scope of the present invention.