Abstract:
A drive train for a treadle scooter using a locking roller clutch on each side of a drive wheel substantially equalizes drive line pull at actuation pulleys operatively associated with the locking roller clutches as a user pivots a rocker board having its ends attached to ends of the drive line.

Description:
COPYRIGHT STATEMENT 
       [0001]    A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
       TECHNICAL FIELD 
       [0002]    The present disclosure is directed to treadle scooters, and more particularly to a drive train for a treadle scooter. 
       BACKGROUND 
       [0003]    Treadle scooters have been in use throughout the world for many years and come in a variety of styles. Broadly speaking, a treadle scooter includes a platform (commonly known as a rocker board) that is pivotally attached to a frame and a drive force is provided to a wheel rotatably attached to the frame through a drive train by a user pivoting the platform relative to the frame using his or her feet. 
         [0004]      FIG. 1  illustrates a particular form of a prior art treadle scooter  10 . The treadle scooter  10  consists of a frame  12  in the form of a simple truss formed by first and second inclined segments  14 ,  16  connected at their proximal ends with their distal ends joined by a horizontal member  18 . The frame  12  of the prior art treadle scooter  10  further consists of a forward member  20 . A first wheel  22  is rotatably mounted to a first or front end of the frame  12  at a distal end of the forward member  20 . A second wheel  24  is rotatably mounted to a second or rear end of the frame  12  between a pair of stays  16   a ,  16   b , which form the inclined member  16 , by an axle  25 . More particularly, the first wheel is attached to first end of the frame by means of a head tube  26  that is attached to the distal end of the forward member  20  and receives a steering shaft  28  having a handle bar  30  at its top end. A front fork  32  is attached to a bottom end of the steering shaft  28  and the first wheel  22  is received between opposing legs of the front fork  32  and rotatably attached to the front fork  32  by the axle  34 . 
         [0005]    In the prior art treadle scooter  10 , a drive train  36  is provided to drive rotation of the second wheel  24 . The drive train  36  consists of a rocker board  38  which is pivotally attached to the frame  12  at an apex of the inclined segments  14 ,  16  by a hinge  40  (see  FIG. 2 ). The rocker board  38  consists of a first or front portion  42  and a second or rear portion  44  on opposite sides of the hinge  40 . The hinge  40  is located at the lengthwise center of the rocker board  38 . The top surface of the first portion  42  and the top surface of the second portion  44  of the rocker board  38  are configured to receive a first and second foot of a user operating the prior art treadle scooter  10 . A first one-way clutch  46  is operatively associated with a right side of the second wheel  24  to rotate the second wheel  24  in a drive direction when an actuation pulley  48  fixedly attached to the one-way clutch  46  is rotated in a first direction and to allow free rotation or “freewheeling” of the second wheel when the actuation pulley attached to the first one-way clutch  46  as rotated in a second direction Likewise, a second one-way clutch  50  is operatively associated with the left side of the second wheel  24  to rotate the second wheel  24  in a drive direction when an actuation pulley  52  attached to the second one-way clutch  50  is rotated in a first direction and to allow free rotation of the second wheel  24  when the actuation pulley  52  attached to the second one-way clutch  50  is rotated in a second direction. A guide pulley  54  is rotatably mounted to the frame  12  proximate the front end of the frame  12  and more particularly on the inclined segment  14  and is operatively aligned with the actuation pulley  48  attached to the first one-way clutch  46  to direct a drive line  56  between the guide pulley  54  and the actuation pulley  48 . A tensioning pulley  58  is attached by a tensioning spring  60  in the form of a coil spring to the frame proximate the first end of the frame. The drive line  56  is attached at a first end  62  to a bottom of the rocker board  38  proximate a distal end of the front portion  42 . The drive line  56  thereafter is wrapped approximately 90° around the guide pulley  54  and approximately 180° around the actuation pulley  48  attached to the first one-way clutch  46 . The drive line  56  continues by wrapping 180° around the tensioning pulley  58  and then approximately 90° around the actuation pulley  52  attached to the second one-way clutch  50  and the second end  64  of the drive line  56  is attached to the bottom of the rocker board  38  proximate a distal end of the second end  44  of the rocker board  38 . In the prior art embodiment illustrated in  FIG. 2 , the drive line  56  includes a first chain segment  66  extending between the first end  62  and around the guide pulley  54  and the actuation pulley  48  attached to the first one-way clutch  46  and a second chain segment  68  extending between the second end  64  and the actuation pulley  52  attached to the second one-way clutch  50  and an intermediate cable portion  70  between the first and second chain segments  66 ,  68  extending around the tensioning pulley  58 . In this embodiment the guide pulley  54  and both the actuation pulleys  48 ,  52  each have radially extending teeth configured to engage the lengths of the respective first and second chain segments in a manner well known in the art. Other embodiments could consist of the drive line  56  being a cable with the teeth of the guide pulley  54  and the actuation pulleys  48 ,  52  being replaced with a circumferential groove. 
         [0006]    Referring to  FIG. 3 , in use, when the rocker board  38  is actuated by a user to lower the second or rear end  44  of the rocker board, the first or front end  42  of the rocker board and the associated second end of the drive line  62  is pulled upward rotating the actuation pulley  48  and the attached first one-way clutch  46  in the first direction, thereby rotating the second wheel in the drive direction, and rotating the actuation pulley  52  and the attached second one-way clutch  50  in the second direction, allowing free rotation of the second wheel. Referring to  FIG. 4 , when the rocker board  38  is actuated by the user to lower the first end  42  of the rocker board  38 , the second end  44  of the rocker board  38  and associated second end  64  of the drive line  56  is pulled upward rotating the actuation pulley  52  and the attached second locking roller clutch  50  in the first direction, thereby rotating the second wheel  24  in the drive direction and rotating the actuation pulley  48  and the attached first one-way clutch  46  in the second direction, allowing free rotation of the second wheel  24 . With no pivoting of the rocker board  38 , neither the first nor the second one-way clutches are engaged in the first direction, leaving the second wheel free to rotate in the drive direction 
         [0007]    One form of one-way clutches known in the art are ratchet clutches  71  schematically illustrated in  FIG. 5  consisting of a first ring shaped outwardly extending flange  72  having a plurality of teeth shaped recesses  73  extending around an internal recess of the flange  72 . A number of ratchets or fingers  74  are provided (one shown in  FIG. 5  for simplicity) which are spring-biased (spring not shown) outwardly to engage the tooth shaped recesses  73  and are shaped and oriented so that the ratchet  71  can freely rotate in one direction  75  but is prevented from rotating in the opposite direction since the fingers are biased to engage the recesses. Such a ratchet structure is described in greater detail in U.S. Pat. No. 7,914,027, the content of which is expressly incorporated by reference herein. Such one-way ratchet clutches have a backlash equal to the ratchet tooth spacing which inhibits immediate actuation of a drive force in use. In addition, such one-way ratchet clutches make a clicking sound when free-wheeling. Furthermore, such one-way ratchet clutches suffer wear during free-wheeling. 
         [0008]    A preferred one-way clutch is a locking roller clutch which could include a conventional locking roller clutch  76  shown schematically in  FIG. 6  with rollers  77  residing in an outer casing  78  spring biased (spring not shown) to drive up ramps  79  associated with a shaft  80  within the locking roller clutch  76  or locking needle roller clutch  76   a  shown schematically in  FIG. 5  having ramps  79   a  in an outer casing  78   a  and rollers  77   a  directly contacting a shaft  80   a  or hub residing within the outer casing  78   a  that are spring-biased (spring not shown) up the ramps  79   a . Either form of locking roller clutch provides near instantaneous rotational drive when rotated in a drive direction, is silent when freewheeling and experiences little wear when freewheeling. However, in use, locker roller clutches deployed in a prior art treadle scooter  10  as depicted in  FIGS. 1-4  require slightly less chain pull on the left side of the drive train and greater force to be applied to the front of the rocker board  38  in order to drive the second locking roller clutch  50 . 
         [0009]    The present invention is directed toward overcoming one or more of the problems with prior art treadle scooter drive trains using locking roller clutches. 
       SUMMARY OF THE EMBODIMENTS 
       [0010]    A first aspect of the disclosure is a drive train for a treadle scooter, the treadle scooter comprising a frame having a first end and a second end, the first end of the frame rotatably supporting a first wheel and the second end of the frame rotatably supporting a second wheel. A rocker board is pivotably attached to the frame proximate a lengthwise center of the rocker board between a first portion and a second portion of the rocker board, the rocker board having a top surface configured to receive a first foot of a user on the first portion and a second foot of a user on the second portion and a bottom surface. A tensioning pulley is attached by a tensioning spring to the frame proximate the first end of the frame. A first locking roller clutch is operatively associated with a right side of the second wheel to rotate the second wheel in a drive direction when an actuation pulley operatively associated with the first locking roller clutch is rotated in a first direction and to allow free rotation of the second wheel when the actuation pulley operatively associated with first locking roller clutch is rotated in a second direction. A second locking roller clutch is operatively associated with the left side of the second wheel to rotate the second wheel in a drive direction when an actuation pulley operatively associated with the second locking roller clutch is rotated in a first direction and to allow free rotation of the second wheel when the actuation pulley operatively associated with the second locking roller clutch is rotated in a second direction. A guide pulley attached to the frame proximate the first end of the frame below the rocker board and operatively aligned with the actuation pulley operatively associated with the first locking roller clutch. An auxiliary pulley is attached to the frame above the actuation pulley operatively associated with the second locking roller clutch and operatively aligned therewith. A drive line attached at a first end to the bottom of the rocker board proximate a distal end of the first portion, the drive line thereafter being operatively associated with the guide pulley, the actuation pulley operatively associated with the first locking roller clutch, the tensioning pulley, the actuation pulley operatively associated with the second locking roller clutch, the auxiliary pulley and attached at a second end to the bottom of the rocker board proximate a distal end of the second portion. When the rocker board is actuated by a user to lower the second end of the rocker board, the first end of the drive line is pulled upward rotating the actuation pulley operatively associated with the first locking roller clutch in a first direction, rotating the second wheel in the drive direction and rotating the actuation pulley operatively associated with the second locking roller clutch in the second direction, allowing free rotation of the second wheel. When the rocker board is actuated by a user to lower the first end of the rocker board, the second end of the drive line is pulled upward rotating the actuation pulley operatively associated with the second locking roller clutch in the first direction, rotating the second wheel in the drive direction and rotating the actuation pulley operatively associated with the first locking roller clutch in the second direction allowing, free rotation of the second wheel. 
         [0011]    Embodiments further may include the actuation pulley being attached to the frame in a position substantially equalizing the length of drive line pull by the first and second ends of the rocker board acting on the actuation pulleys operatively associated with the first and second locking roller clutches. 
         [0012]    Embodiments may include the auxiliary pulley being attached to the frame in a position directing the drive line pull on the actuation pulley operatively associated with the second locking roller clutch from a direction forward of an axis of the actuation pulley operatively associated with the second locking roller clutch. 
         [0013]    Embodiments may include an axis of the auxiliary pulley being at about 12 o&#39;clock relative to an axis of the actuation pulley operatively associated with the second locking roller clutch when viewed from the left side of the treadle scooter. 
         [0014]    Embodiments may further include a periphery of the auxiliary pulley being in close proximity to a periphery of the actuation pulley operatively associated with the second locking roller clutch. Embodiments include the auxiliary pulley having flanges extending radially on opposing sides of the radially extending teeth beyond the distal ends of the radially extending teeth, the distal ends of the flanges defining the periphery of the auxiliary pulley. 
         [0015]    Embodiments may include the drive train being configured such that when a user provides no pivoting of the rocker board, the second wheel freely rotates in the drive direction. 
         [0016]    Embodiments may further include the line having a first chain segment extending between the first end and around the guide pulley and the actuation pulley operatively associated with the second locking roller clutch and a second chain segment extending between the second end and around the auxiliary pulley and the actuation pulley operatively associated with the second locking roller clutch and an intermediate cable portion between the first and second chain segments extending around the tensioning pulley and the guide pulley, both the actuation pulleys and the auxiliary pulley having radially extending teeth configured to engage links of the respective first and second chain segments. 
         [0017]    Various embodiments of the drive train can equalize the length of the drive line pull by the first and second ends of the rocker board acting on the actuation pulleys operatively associated with first and second locking roller clutches, which equalize the amount of force a user must apply to each side of the rocker board in use. This promotes a feeling to the user that he or she is providing equal power whether the front or rear portion of the rocker board is pushed downward. It further provides for equalization of the power applied to the rear wheel regardless of whether the front or rear portion of the rocker board is depressed. Use of the auxiliary pulley in accordance with the various embodiments also eliminates chain jumping when the user is vigorously pivoting the rocker board. The embodiments may further improve efficient transmission of energy from the rocker board to the drive wheel. Embodiments may also serve to protect a user&#39;s fingers from inadvertent pinching between the pulleys and the chain associated with the drive wheel. 
         [0018]    Various modifications and additions can be made to the embodiments discussed without departing from the scope of the invention. For example, while the embodiments described above refer to particular features, the scope of this invention also included embodiments having different combination of features and embodiments that do not include all of the above described features. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    A further understanding of the nature and advantages of particular embodiments may be realized by reference to the remaining portions of the specification and the drawings, in which like reference numerals are used to refer to similar components. In some instances, a sub-label is associated with a reference numeral to denote one of multiple similar components. When reference is made to a reference numeral without specification to an existing sub-label, it is intended to refer to all such multiple similar components. 
           [0020]      FIG. 1  is perspective view of a prior art treadle scooter featuring a prior art drive train; 
           [0021]      FIG. 2  is a bottom plan view of the treadle scooter of  FIG. 1  more clearly illustrating the drive train thereof; 
           [0022]      FIG. 3  is a schematic, perspective view of the prior art drive train of  FIGS. 1 and 2  illustrating the path of a drive line of the drive train from the left side with a user applying force to the rear of the rocker board; 
           [0023]      FIG. 4  is a schematic, perspective view of the prior art drive train of  FIGS. 1 and 2  illustrating the path of a drive line of the drive train from the left side with a user applying force to the front of the rocker board; 
           [0024]      FIG. 5  is a schematic front elevation view of a ratchet clutch; 
           [0025]      FIG. 6  is a schematic front elevation view of a conventional locking roller clutch; 
           [0026]      FIG. 7  is a schematic front elevation view of a locking needle roller clutch 
           [0027]      FIG. 8  is a schematic, perspective view of an embodiment of a drive train including an auxiliary pulley viewed from the left side; and 
           [0028]      FIG. 9  is a perspective view of the path of the drive line of the embodiment illustrated in  FIG. 8  showing a drive line comprising first and second chain segments and an intermediate cable portion therebetween. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    While various aspects and features of certain embodiments have been summarized above, the following detailed description illustrates a few embodiments in further detail to enable one of skill in the art to practice such embodiments. The described embodiments are provided for illustrative purposes and are not intended to limit the scope of the invention. 
         [0030]    In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the described embodiments. It will be apparent to one skilled in the art, however, that other embodiments of the present invention may be practiced without some of these specific details. Several embodiments are described and claimed herein, and while various features are ascribed to different embodiments, it should be appreciated that the features described with respect to one embodiment may be incorporated with other embodiments as well. By the same token, however, no single feature or features of any described or claimed embodiment should be considered essential to every embodiment of the invention, as other embodiments of the invention may omit such features. 
         [0031]    Unless otherwise indicated, all numbers used herein to express quantities, dimensions, and so forth used should be understood as being modified in all instances by the term “about.” In this application, the use of the singular includes the plural unless specifically stated otherwise, and use of the terms “and” and “or” means “and/or” unless otherwise indicated. Moreover, the use of the term “including,” as well as other forms, such as “includes” and “included,” should be considered non-exclusive. Also, terms such as “element” or “component” encompass both elements and components comprising one unit and elements and components that comprise more than one unit, unless specifically stated otherwise. 
         [0032]      FIG. 8  schematically illustrates an embodiment of the drive train in accordance with the present disclosure. The drive train is largely as described above with reference to prior art  FIGS. 1-4 , but includes an auxiliary pulley  80  attached to the rear left inclined member  16   a  by a bracket  82  above the actuation pulley  52  attached to the second one-way clutch  50 , which in the embodiment of  FIG. 8  is a locking roller clutch  50   a . Referring to  FIGS. 8 and 9 , an axis  84  of the auxiliary pulley  80  is positioned at about 12 o&#39;clock relative to an axis  86  of the second locking roller clutch  50   a . Referring to  FIG. 9 , the auxiliary pulley  80  has a pair of radial flanges  88  on opposing sides of the radially extending teeth  90  and extend radially beyond the radially extending teeth  90 . The periphery of the radial flanges  88  forms the periphery of the auxiliary pulley  80 . The periphery of the auxiliary pulley  80  as seen in  FIGS. 8 and 9  is in close proximity to a periphery of the actuation pulley  52  attached to the second locking roller clutch  50   a . In this manner, a user&#39;s fingers are prevented from coming between the auxiliary pulley  80  and the second locking roller clutch  50   a . The radially extending flanges  88  function both to prevent a user&#39;s finger from being caught in the auxiliary pulley  80  and to minimize the possibility of the second chain segment  68  becoming disengaged from the pulley teeth. In this position the auxiliary pulley  80  functions to substantially equalize the length of drive line pull by the first and second ends of the rocker board  38  actuating the actuation pulley attached to the first and second locking roller clutches  48   a ,  50   a . In addition, in this position the drive line is connected to pull on the actuation pulley  52  attached to the second locking roller clutch  50   a  from a direction forward of an axis of the actuation pulley  52  attached to the second locking roller clutch  50   a . In this manner, the direction of chain pull is similar to that provided on the first locking roller clutch  48   a  (see  FIGS. 3 and 8 ). This location of the auxiliary pulley also causes more than 90° of drive line to wrap around the actuation pulley  52 . 
         [0033]      FIG. 9  also illustrates a location for a brake  100  to maximize braking power. As illustrated in  FIG. 9 , the brake  100  comprises a brake arm  102  pivotably connected to attachment brackets  104  extending from the stays  16   a  and  16   b . A brake cable  106  is attached to a first end of the brake arm  102  and actuated by the brake lever  108  tensioning the brake cable  106 . This pivots the brake shoe  110  into contact with a running surface  112  of the second wheel  24 . The spring  112  biases the brake arm  102  with the brake shoe  110  out of contact with the running surface  112 . The brake  100  is positioned relative to the second wheel  24  so that the wheel spins into the brake shoe  110  driving it toward the stays  16   a ,  16   b  and causing application of an enhanced braking force to the running surface  112 . Thus, the effect on the running surface  112  rotating wheel  24  contacting the brake shoe  110  enhances the brake effectiveness over a prior art brake located as viewed in  FIG. 1 , where a brake shoe  110   a  contacts the running surface of a wheel without the possibility of the spinning wheel driving the brake shoe toward the frame  12  or positively effecting the braking force.