Abstract:
A rotational assembly hub can include a sprocket that is configured to rotate about an axis, where the sprocket can be located on a first side of a driver. Moveable paws can be located on a second side of the driver that is opposite the first side of the driver. The moveable paws can be configured to move from a recessed position within the driver to a protruding position when the driver rotates in a first direction in a first rotational mode and can be configured to remain protruding from the recessed position when rotated in the first direction in a second rotational mode. Other assemblies are also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Taiwanese Patent Application No. M440895, filed on May 8, 2012, and of Chinese Patent Application 201220549568.5 filed on Oct. 25, 2012, the contents of all of which are hereby incorporated herein by reference in their entireties. 
       FIELD 
       [0002]    The present invention relates generally to the field of rotational assemblies and, more particularly, to hubs for rotational assemblies. 
       BACKGROUND 
       [0003]      FIG. 1  illustrates a known BMX/Freestyle bicycle configuration. The bicycle  10  includes a frame  11 , back wheel  14 , front wheel  14 ′, and driver system  15 . The back wheel  14  and front wheel  14 ′ are mounted to the front and back of frame  11  via the front suspension cradle  12  and back suspension cradle  13 , respectively. The driver system  15  includes pedals  16 , a first sprocket  17 , a chain  18 , and a bicycle hub assembly  100 . A rider can spin the first sprocket  17  by pushing the pedals  16  in a circular motion, which moves the chain  18 . 
         [0004]    The bicycle hub assembly  100  can rotate in response to movement of the chain  18 , which can spin the back wheel  14  (and possibly the front wheel  14 ′) to move the bicycle  10  forward. Additionally, pegs  19  and pegs  19 ′ are coupled to the back wheel  14  and front wheel  14 ′, respectively, to enable the rider to perform stunts. 
         [0005]      FIG. 2  is a more detailed illustration of the bicycle hub assembly  100 . The bicycle hub assembly  100  includes an axle  110 , a hub  120 , a driver  130 , an internal gear wheel  140 , and a series of bearings  150 . The hub  120  can be driven on the bearings  150  about the axle  110 . 
         [0006]      FIG. 3  shows a lateral view of the driver  130  and internal gear ring. The driver  130  includes a second sprocket  132  and a series of paws  134 . The paws  134  are arranged around the driver  130  in a circular pattern. 
         [0007]      FIG. 4  illustrates a body of the hub and internal gear wheel. The first right hand thread RHT  142  is on the outer surface of the internal gear wheel  140 . The second RHT  122  is on the inside surface of the body of bicycle hub  120 . The first and second RHT  142 ,  122  can be threaded clockwise together, which fixes the internal gear ring  140  inside the body of the bicycle hub  120 . 
         [0008]    According to  FIGS. 3 and 4 , the rotation of the driver causes the paws  134  to engage with the internal teeth  144  on the internal gear ring  140 . This action spins the internal gear ring  140 , causing the body of bicycle hub  120  to be driven which moves the bicycle  10  forward. 
         [0009]    When the second sprocket  132  is rotated counterclockwise by the chain  18 , the paw  134  of the driver  130  can slide past the internal teeth  144  of the internal gear ring, so that the body of the hub  120  is not driven (sometimes referred to as “idle running”). In “idle running”, when the paw  134  of the driver  130  slides past the internal teeth  144  on the internal gear ring, a “clicking” noise may occur which is commonly associated with convention hub assemblies. 
         [0010]    Referring to  FIG. 3 , when the internal gear ring  140  spins clockwise, the internal teeth  144  of the internal gear ring  140  slides past the paw  134 . When the back wheel  14  is “idle running” backward (meaning that the internal gear ring  140  also spins counter-clockwise) the internal teeth  144  of internal gear ring  140  engages with the paw  134 , which spins the driver  130  backward (counterclockwise) causing the driver  130  to pull the chain  18  and drive the pedals backward (counterclockwise). 
         [0011]    A Freecoaster bicycle hub is also discussed in, for example, Taiwanese Patent Publication Number TW-201113167. 
       SUMMARY 
       [0012]    Embodiments according to the present invention can provide rotational hub assemblies that are reconfigurable to have different rotational modes. Pursuant to these embodiments, a rotational assembly hub can include a sprocket that is configured to rotate about an axis, where the sprocket can be located on a first side of a driver. Moveable paws can be located on a second side of the driver that is opposite the first side of the driver. The moveable paws can be configured to move from a recessed position within the driver to a protruding position when the driver rotates in a first direction in a first rotational mode and can be configured to remain protruding from the recessed position when rotated in the first direction in a second rotational mode. 
         [0013]    In some embodiments according to the invention, the driver includes troughs, where the hub can further include first removable springs in the troughs that can be configured to provide a first force on the moveable paws toward the recessed position. In some embodiments according to the invention, the troughs each include circular arc shaped sub-troughs located on opposing ends of the troughs. In some embodiments according to the invention, first portions of the first removable springs can be configured for insertion into the sub-troughs. In some embodiments according to the invention, the hub can further include second portions of the first removable springs, wherein the paws each include first and second opposing jaws linked together by a linkage surface that is recessed relative to outer surfaces of the first and second jaws and can be configured to engage with the second portions of the first removable springs. 
         [0014]    In some embodiments according to the invention, the driver can include recesses, and the hub can further include second removable springs in the troughs that can be configured to provide a second force on the moveable paws toward the protruding position. In some embodiments according to the invention, the troughs can each include circular arc shaped sub-troughs located on opposing ends of the troughs. In some embodiments according to the invention, first portions of the second removable springs can be configured for insertion into the sub-troughs. 
         [0015]    In some embodiments according to the invention, the hub can further include second portions of the second removable springs that can be configured to engage with bottom surfaces of the paws. In some embodiments according to the invention, the hub can further include a clutch that can include a first side thereof facing the first side of the driver to selectively engage with the moveable paws in the first rotational mode. In some embodiments according to the invention, the clutch can include a second side thereof that is opposite the first side of the driver, where the second side can be configured to face the first side of the driver in the second rotational mode, that can be configured to remain spaced apart from the first side of the driver in the second rotational mode. 
         [0016]    In some embodiments according to the invention, the hub can further include a spring configured for placement to surround the axis of rotation and to force the clutch to contact the first side of the driver. In some embodiments according to the invention, the hub can be a BMX style bicycle wheel hub. In some embodiments according to the invention, the first rotational mode can be a Freecoaster configuration rotational mode and the second rotational mode can be a Cassette configuration rotational mode. In some embodiments according to the invention, a surface of the paws that faces away from the sprocket is substantially planar and is free on a protrusion. In some embodiments according to the invention,            
         [0017]    In some embodiments according to the invention, a BMX bicycle hub can include a rider re-configurable driver including a sprocket configured to rotate about a BMX bicycle axle, the rider re-configurable driver configured to provide a Freecoaster configuration rotational mode in a first configuration and provide a Cassette configuration rotational mode in a second configuration. 
         [0018]    In some embodiments according to the invention, a rotational hub assembly can include a driver including a sprocket that can be configured to rotate about an axis of the driver rotation and can include spaced-apart troughs in an outer circumferential surface of the driver and separate springs that can be configured for insertion into each of the spaced-apart troughs in the outer circumferential surface of the driver. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is an illustration of a BMX freestyle bicycle according to the prior art. 
           [0020]      FIG. 2  is a detailed cross-sectional view of the bicycle hub shown in the  FIG. 1 . 
           [0021]      FIG. 3  is side view of the ratchet wheel and the internal gear ring shown in  FIG. 2 . 
           [0022]      FIG. 4  is perspective view of the bicycle hub and the internal gear ring shown in  FIG. 2 . 
           [0023]      FIG. 5  is an exploded view of a hub in some embodiments according to the present invention. 
           [0024]      FIG. 6A  is a side view of a ratchet wheel in some embodiments according to the present invention. 
           [0025]      FIG. 6B  is a perspective view of a paw in some embodiments according to the present invention. 
           [0026]      FIG. 7  is a side view of a clutch in some embodiments according to the present invention. 
           [0027]      FIG. 8  is a side view of the ratchet wheel actuated by the clutch in the Freecoaster configuration mode of rotation in some embodiments according to the present invention. 
           [0028]      FIG. 9  is a side view of the ratchet wheel in the Cassette configuration mode of rotation in some embodiments according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0029]    In some embodiments according to the invention, a hub assembly (such as a hub assembly for a BMX style bicycle) can be configured in a “cassette mode” or in a “Freecoaster mode.” In the cassette mode, the hub allow a wheel to be mechanically engaged by paws when the wheel moves in both forward and reverse directions so that, for example, when the wheel rotates backwards, the pedals also rotate backwards. In the Freecoaster mode, however, the hub allows the wheel to be mechanically engaged by paws only when the wheel moves in the forward direction, whereas the wheel is not mechanically engaged by the paws when the wheel moves in the reverse direction. Accordingly, when the wheel rotates backwards in Freecoaster mode, for example, the pedals do not rotate backwards. 
         [0030]    In some embodiments according to the invention, a bicycle hub assembly includes an axle, a driver, an internal gear wheel, a hub, clutch and a second elastic spring. The driver is disposed around the axle wherein the driver includes at least one sprocket, a series of troughs, a series of paws and a series of first springs. The sprocket is located on one side of the driver and the trough is located on the opposite side of the driver relative to the sprocket. The trough can have a first sub-trough and a second sub-trough. The paw has a first end and a second end. The first spring has a first end and a second end. The internal gear ring surrounds the paws and a series of teeth (sometimes referred to as gears) on then internal surface of the internal gear ring. A hub is disposed around the axle. The clutch has an axial hole and a cam. The cam has multiple protruding parts. The second spring is disposed around the axle. 
         [0031]    In some embodiments according to the invention, a bicycle hub assembly includes an axle, a driver, an internal gear wheel, a hub, a clutch and a second elastic spring. The driver is disposed around the axle, and the driver includes at least one sprocket, a trough, paws and first springs. The sprocket is placed at one side of the driver. The trough is placed at another side of the driver. The trough has a first sub-trough and a second sub-trough and both of the sub-troughs have circular arcs. The trough also includes a bottom surface between the first sub-trough and the second sub-trough. Moreover, the paw has a first end and a second end. The first end of the paw is placed inside the first sub-trough with the first spring, where the first spring has a first end and a second end. The first end of the first spring is placed inside the second sub-trough and the elasticity is provided to the paw by the second end of the first spring. 
         [0032]    In some embodiments according to the present invention, internal teeth are included on the interior surface of the internal gear ring. The internal teeth are configured to mechanically engage with the second end of the paw. The hub is disposed around the axle, and the clutch includes an axle hole through which the axle passes. The clutch includes a cam having a plurality of blocks on the cam spaced apart around the circumference thereof to selectively engage with the paws. The second spring is disposed around the axle. The elasticity of the second spring can force the clutch against the paws. 
         [0033]    In some embodiments according to the present invention, when the driver spins in a first direction relative to the clutch, the block of the cam will engage with the paws. This action makes the second end of the paw lift out of the trough to mechanically engage with the internal teeth, whereas when the driver spins in the second direction relative to the clutch, the block of the cam disengages from the paws, whereupon the elasticity of the first spring causes the paw to return to the trough. It will be understood that the first direction and the second directions can be opposite to one another. 
         [0034]    In some embodiments according to the present invention, the first sub-trough and the second sub-trough are symmetrical to one another. 
         [0035]    In some embodiments according to the present invention, the paw includes a first jaw, a second jaw, and a linkage surface linking the first and second jaws together. The linkage surface is configured to be engaged by the second end of the first spring to hold the paw in the trough. The paw will be moved away from the block of the cam of the clutch when the ratchet wheel spins through the second direction. This action makes the elasticity of the first spring force the paw into the trough toward the linkage surface. 
         [0036]    In some embodiments according to the present invention, a collar is located around the axle between the clutch and the driver. In some embodiments according to the present invention, the collar includes metal. 
         [0037]      FIG. 5  is an exploded view of a hub in some embodiments according to the present invention.  FIG. 6A  is a side view of a ratchet wheel configured in Freecoaster configuration mode of rotation, in some embodiments according to the present invention. Referring to  FIGS. 5 and 6A , in some embodiments according to the present invention, the hub  200  includes an axle  210 , a hub  220 , a driver  230 , an internal gear ring  240 , a clutch block  250 , and a second spring  260 . The hub  220  and the driver  230  are disposed around the axle  210 . The driver  230  includes a sprocket  232 , several troughs  234 , paws  236 , and first springs  238 . The sprocket  232  is located on one side of the ratchet  230  and the troughs  234  are located on the other side of the sprocket  232  and each trough  234  includes first and second sub-troughs  234   a,    234   b,  both of which may have a circular arc shape. The first and second troughs  234   a  and  234   b  can be symmetrical with each other and a bottom surface  234   c  links the first and second sub-troughs  234   a.    
         [0038]    In some embodiments according to the present invention, in the Freecoaster configuration mode of rotation, the paws  236  include a first end  236   a  and a second end  236   b,  where the both ends  236   a  and  236   b  can be recessed inside the first trough  234   a  so that at least any protrusion of the paws from the trough  234   a  is small enough to avoid the internal teeth from engaging with the internal gear ring  240  unless engaged by the cam and blocks. The first springs  238  include a first end  238   a  and a second end  238   b,  where the first end  238   a  of the first spring  238  is recessed inside the sub-trough  234   b  and the second end  238   b  of first spring  238  provides tension on the paw  236  to keep the paw  236  recessed within the trough  234 . The internal gear ring  240  includes internal teeth  242  set on the internal surface of the internal gear ring  240 . The internal teeth  242  are suitable for the second end  236   b  of the paw  236  to mechanically engage when the sprocket  232  rotates in the clockwise direction, for example. 
         [0039]      FIG. 6B  is a perspective view of a paw in some embodiments according to the present invention. In some embodiments according to the present invention, the paw  236  includes a first jaw  236   c,  a second jaw  236   d  and a linkage surface  236   e.  The linkage surface  236   e  links the first jaw  236   c  and the second jaw  238   b  together and defines a channel therebetween. The linkage surface  236   e  can be engaged by the second end  238   b  of the first spring  238  when the hub is configured in the Freecoaster configuration mode of rotation. 
         [0040]      FIG. 7  is a side view of a clutch in some embodiments according to the present invention. According to  FIG. 7 , an axle hole  252  is included in the clutch  250 , which is disposed around the axle by placing the axle through the axle hole  252 . The clutch  250  includes a cam  254  and numerous blocks  256 . In some embodiments according to the present invention, in the Freecoaster configuration mode of rotation the blocks  256  can engage with the paws  236  when the sprocket  232  rotates clockwise. The hub  200  includes a second spring  260  which is also disposed around the axle  210 . 
         [0041]    In some embodiments according to the present invention, one end of second spring  260  provides tension on the clutch  250  to press the clutch  250  against the ratchet wheel  230 . In some embodiments according to the present invention, this action makes the clutch  250  fit closely together with the ratchet wheel  230 . In some embodiments according to the present invention, the hub  200  includes a collar  270 . In some embodiments according to the present invention, the collar  270  can be metal and can be placed in the axle hole  252  of the clutch  250  around the axle  210  in different orientations depending on whether the Freecoaster or Cassette configuration rotational mode is used. 
         [0042]      FIG. 8  is a side view of the ratchet wheel actuated by the clutch in the Freecoaster configuration rotational mode in some embodiments according to the present invention. In some embodiments according to the present invention, when the driver  230 , which is relative to the clutch  250 , spins in the first direction A, the block  256  of the cam  254  will engage with the paw  236  to lift the second end  236   b  of the paw  236  of the trough  234 , as shown. When the driver  236 , which is relative to the clutch  250 , spins in the second direction B, however, the block  256  of the cam  254  will disengage from the paw  236 , thereby allowing the second end  236   b  of the paws  236  to recess back into the trough due to the tension from the first spring  238  applied to the paws  236 . When the paw  236  is recessed into the trough  234 , the paw  236  fits together with the bottom surface  236   c.  It will be understood that the blocks  256  can face toward the paws  236  when the hub is in Freecoaster configuration rotational mode. 
         [0043]    In some embodiments according to the present invention, in the Freecoaster configuration mode of rotation, when the second chain wheel  232  is spun by the chain  18  in the clockwise direction, the sprocket  230  will be engaged by the clutch  250  and spin in the first direction A. The block  256  of the cam  254  engages the paw  236  which makes the second end  236   b  of the paw  236  lift out the trough  234  and engage the internal teeth  242 , causing the internal gear ring  240  to spin. When the internal gear ring  240  spins, the hub  220  will follow, thereby moving the bicycle forward. 
         [0044]    In some embodiments according to the present invention, in the Freecoaster configuration mode of rotation, when second sprocket  232  is pulled by chain  18  to spin counter-clockwise, however, the driver  236  spins in the second direction B and the block  256  of the cam  254  disengages from the paw  236 . In addition, the paw  236  may also disengage from the block  256  of the cam  254  when the wheel spins in a forward direction (assuming that the driver  230  is not spun in the counter-clockwise direction. 
         [0045]    In either case, this action allows the paw  236  to be recessed back into the trough  236  (by the tension of first spring  238 ) to fit closely together with the surface of the bottom  236   c.  Because the paw  236  is recessed into the trough  234 , it can avoid being engaged by the internal teeth  242  of the internal gear ring  240 , such as when the bicycle moves backward, which can also avoid creating the “clicking” noise associated with backward movement of some wheels in the prior art. 
         [0046]    As described herein, the hub  200  can be configured to be in the Freecoaster mode (described for example above in reference to  FIGS. 6-8 ), wherein the hub allows the wheel to be mechanically engaged by paws when the wheel moves in only the forward direction. When the wheel rotates backwards in Freecoaster mode, the pedals do not rotate backwards. It will be understood, however, that when the hub is re-configured to be in the Cassette mode of rotation, the wheel is mechanically engaged by the paws so that the pedals do rotate backwards when the wheel moves backwards. 
         [0047]      FIG. 9  is a side view of the ratchet wheel being reconfigured in the Cassette configuration mode of rotation in some embodiments according to the present invention. In particular, although the hub  200  may be configured to be in Freecoaster mode of rotation, the hub  200  can be re-configured to be in the Cassette mode by replacing the first spring  238  with a first spring  338 . It will be understood that whereas the first spring  238  acts to keep the paw  236  recessed in the trough in the Freecoaster mode, in Cassette mode the first spring  338  in  FIG. 9  lifts one end of the paw  236  out the trough  234  by the tension of the first spring  338 . It will be understood that the blocks  256  can face away the paws  236  when the hub is in Cassette configuration rotational mode as shown, for example, in            
         [0048]    Accordingly, the hub can be configured for Freecoaster mode or Cassette mode by swapping the particular springs used to engage with the paws. For example, the first springs can be used to hold the paws in the troughs (until engaged by the blocks) in Freecoaster mode, whereas the second springs can be used to force the paws to protrude from the troughs without engagement of the blocks. 
         [0049]    Relative terms such as “below” or “above” or “clockwise” or “counterclockwise” may be used herein to describe a relationship of one element to another element as illustrated in the figures. It will be understood that these terms are intended to encompass different orientations of the assemblies in addition to the orientation depicted in the figures. 
         [0050]    Although the present invention has been described in connection with the embodiment of the present invention illustrated in the accompanying drawings, it is not limited thereto. It will be apparent to those skilled in the art that various substitution, modifications and changes may be thereto without departing from the scope and spirit of the invention.