Abstract:
In a bicycle seat assembly a fastener driver is rotatable in first and second directions. Upon rotating the driver in the first direction, it threadably engages a shaft of an adjusting member causing tightening of a connection between a bicycle seat, a seat post and the adjusting member and producing simultaneous adjustment of a wedge sub-assembly provided at an interface between a distal end of the adjusting member and the seat post. Rotation of the fastener driver in the second direction causes at least partial disengagement of the threadable connection between the driver and the adjusting member, resulted in loosening connection between the seat post and the adjusting member.

Description:
FIELD OF INVENTION 
   The invention relates to bicycles in general, more specifically it relates to a method and apparatus for bicycle seat adjustment. 
   BACKGROUND OF INVENTION 
   In the prior art to provide adjustment of a bicycle seat and a bicycle seat post with respect to a bicycle frame, typically one or more bolts are used. An additional independent clamp is also typically provided for securing the bicycle seat post to the tube of the bicycle seat frame. 
   U.S. Pat. Nos. 6,899,389 and 7,059,672 to Saccucci disclose a bicycle seat assemblies concentrating on the adjustment and fixing the angular position of the seat with respect to the frame. However, these patents neither interested nor capable of providing simultaneous adjustment of the seat/seat post with respect to the frame. A special additional device is required for this purpose. 
   U.S. Pat. No. 5,618,052 to Rendall disclose an angle-shaped clamp facilitating vertical adjustment of the seat post within the bicycle frame and fixation thereof after the predetermined elevation is achieved. The Rendall Patent requires a separate independent mechanism for angular adjustment position of the seat with respect to the frame. 
   In both, the Rendall and the Saccucci references there are separate and independent mechanisms are provided for adjustment of the seat with respect to the frame and for adjustment of the post relative to the frame of a bicycle. Provision of two separate mechanisms increases the weight of the bicycle and makes manufacturing of the bicycles more expensive. Furthermore, use of the separate mechanisms complicates adjustment and fixation of the seat as well as adjustment of the seat post within the frame. 
   Thus, it has been long felt and unsolved need for a bicycle seat arrangement which is capable of providing a simple adjustment of the seat as well as the seat post relative to the frame, wherein both actions are carried out simultaneously by using a single integrated mechanism. 
   SUMMARY OF THE INVENTION 
   One aspect of the invention provides a method of adjustment of a bicycle seat assembly which comprises a bicycle seat, and a hollow seat post adapted to receive an elongated adjusting member thereinside. A wedge sub-assembly is formed at an interface between a distal end of the adjusting member and a distal end of the seat post. A fastener driver is associated with the bicycle seat and adapted for engagement with a proximal end of the elongated adjusting member. In the method, the fastener driver is engaged with the proximal end of the elongated adjusting member. Then the fastener driver can be rotated in two opposite directions. Upon rotation of the fastener driver in a first direction tightening connection between the bicycle seat, the seat post and the elongated adjusting member occurs which causes fixing the bicycle seat in a predetermined position. Such rotation in the first direction causes simultaneous tightening of the wedge sub-assembly resulted in fixing position of the seat post within the bicycle frame. Upon rotation of the fastener driver in the second direction loosening of the connection between the bicycle seat, the seat post and the elongated adjusting member occurs allowing repositioning of the bicycle seat. Rotation of the driver in the second direction simultaneously causes loosening of the wedge sub-assembly so as to allow movement of the seat post within the bicycle frame. 
   As to another aspect of the invention, the engagement between the fastener driver and the proximal end of the adjusting member is a threadable engagement. In this manner, when the fastener driver is rotated in the second direction, a threadable connection is at least partially disengaged and in the step of rotating the fastener driver in the first direction, the threadable connection is engaged. The wedge sub-assembly consists of a wedge-shaped element provided at the distal end of the seat post. The distal end of the adjusting member is formed with a wedge-shaped member adapted for engagement for engaging the wedge-shaped element of the seat post. Upon rotation of the fastener driver in the first direction, the wedge-shaped element and member of the wedge sub-assembly are drawn against each other causing misalignment thereof within the bicycle frame. In this manner, the seat post is fixed within an interior of the bicycle frame. 
   As to the a further aspect of the invention, upon rotation of the fastener driver in the second direction, an engagement between the wedge-shaped element and member is minimized resulted in the reduced friction between the wedge-assembly and the interior of the frame so as to allow movement of the seat post thereinside. 
   As to still another aspect of the invention, the bicycle seat assembly further comprises a seat support structure positioned between the proximal end of the seat post and the bicycle seat. Thus, in the step of rotation the fastener driver in the second direction, position of the seat relative to the support structure is adjustable. On the other hand, when the fastener driver is rotated in the first direction, position of the seat with respect to the seat support structure is fixable. 
   The main purpose of this invention is to reduce the weight of the bicycle and to simplify assembly and adjustment of the bicycle seat. Previously, the bicycle seat is adjusted by using multiple bolts to tighten the seat at the desired angle. Furthermore, in the prior art, an additional single bolt or a pair of bolts are utilized to tighten the seat onto the bicycle frame at the desired height. The present invention utilizes a single fastener driver to simultaneously tighten the angle of the seat as well as the height of the seat post within the bicycle frame. In this manner, only one tool is used to simplify adjustment, removal and or installation of the seat to the bicycle frame. Utilization of the single fastener driver reduces weight of the bicycle and performs the same task. 
   The design of the bicycle frame associated with the invention eliminates the seat tube or a receptacle extension above the top tube of the bicycle frame. This further reduces the weight and improves the appearance of the bicycle providing the assembly with a better esthetic appearance when installed into the bicycle frame. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be further discussed and illustrated in the drawings in which: 
       FIG. 1  is a view showing the apparatus for adjustment of bicycle seat assembly of the invention; 
       FIG. 2A  is a view of the bicycle seat assembly illustrating rotation of a fastener driver in the first direction; 
       FIG. 2B  is a view of the bicycle seat assembly illustrating rotation of a fastener driver in the second direction; 
       FIG. 3  is a partial section view of the apparatus of the invention; 
       FIG. 4  is a front elevational view of a seat post with an elongated adjusting member; 
       FIG. 5  is a section view according to section line  5 - 5  of  FIG. 4 ; 
       FIG. 6  is a top plan view of  FIG. 4 ; 
       FIG. 7  is a front elevational view of the seat post; 
       FIG. 8  is a section view according to section line  8 - 8  of  FIG. 7 ; 
       FIG. 9  is a top plan view of  FIG. 7 ; 
       FIG. 10  is a front elevational view of the elongated adjusting member; 
       FIG. 11  is a top plan view thereof; and 
       FIG. 12  is a section view according to section line  12 - 12  of  FIG. 10 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings in general and more specifically to  FIGS. 1-12  which show a bicycle seat assembly  10  in accordance with the present invention. The seat assembly  10  consists of a tubular seat post  12 , and a seat sub-assembly which includes a seat support structure  14  and a seat  16 . The seat post tube  12  has a distal end  18  adapted to be installed into a tube or receptacle  20  in a bicycle frame  22 , and a proximal end  24  provided for connection to the seat support structure. A shaft or adjusting member  40  is formed with a threaded central aperture  48  provided at a top area  46  and extends along a longitudinal axis thereof. In the preferred embodiment, the seat post  12  is substantially hollow and the distal end  18  is formed having wedge-shaped configuration. The elongated adjusting member  40  is movably positioned within the hollow interior of the post tube  12 . A bottom area  42  of the adjusting member  40  is formed with a wedge-shaped member  44  adapted for engagement with the wedge-shaped distal end  18  of the seat post  12 . In the preferred embodiment of the invention, the member  44  is formed having tubular-shaped configuration with the top angle-shaped portion  45  positioned at an angle to the longitudinal axis of the shaft. The central aperture  48  is formed with internal threads and is adapted to receive a driver or fastener  30  having a threaded stem  32  and a head  34 . The external threads of the stem  32  are provided for threadable engagement with the internal threads of central aperture  48 . When inserted into the threaded aperture, the fastener  30  is a co-axial relationship with the threaded aperture  48 , the adjusting member  40  and the seat post  12 . Further, when screwed into the threaded aperture  48  of the adjusting member  40 , the fastener  30  is aligned with the longitudinal axis of the seat post  12 . Such arrangement maximizes the strength and durability of the seat assembly  10 . This is because the fastener  30  is not exposed to any lateral moments (e.g., forces) during use. 
   A wedge sub-assembly  50  is formed at an interface between the bottom area  42  of the adjusting member and the distal end  18  of the seat post. More specifically, the wedge sub-assembly consists of the wedge-shaped member  44  of the adjusting member adapted for engagement with the wedge-shaped distal end  18  of the seat post. The wedge-shaped distal portion  18  of the seat post  12  can be cut approximately at 37 degree angle at the bottom of the post, so as to accept the wedge-shaped top surface  45  of the adjusting member formed with a mating 37 degree angle. These two angle-shaped members are engaged by tightening the fastening driver  30  associated with the seat. In this manner, the wedge-shaped surface  45  and the wedge-shaped end  18  are forced against one another inside of the seat tube of the bicycle effectively expanding (see  FIGS. 2A and 3 , for example) and clamping the seat post  12  within the interior of the tube receptacle  20 . 
   During the rotational motion of the fastener driver  30  in the first direction, (illustrated by the arrow A in  FIG. 2A ) the adjusting member  40  moves longitudinally within the longitudinal aperture  28  of the seat post toward the seat  16 . In this manner, the wedge-shaped elements  18  and  44  are drawn against each other causing tightening and misalignment of the sub-assembly  50  within the interior of the tube receptacle  20 . This motion causes fixation of the seat post  12  within the receptacle  20 . On the other hand, during rotational motion of the fastener driver  30  in the second direction, opposite to the first direction, (illustrated by the arrow B in  FIG. 2B ) the adjusting member  40  moves longitudinally within the hollow interior of the seat post  12  in the opposite direction, away from the seat  16 . Thus, the wedge-shaped elements  18  and  44  are drawn away from each other causing relaxation of the sub-assembly  50 , allowing alignment of the wedge-shaped elements  18  and  44  with respect to each other. 
   One embodiment of the present invention is adapted for use with a seat  16  formed with a slit  17  adapted for passage the fastener driver  30 . This arrangement facilitates quick and easy attachment, removal and re-adjustment of the seat  16  and support structure  14  from the seat post  12 , or to adjust the seat angle. 
   Although, the threadable connection between the fastener driver  30  and the adjusting member  26  has been described hereinabove, it should be obvious to a person skilled in the art that any conventional connection between these two elements is within the scope of the invention. 
   The cross-sectional shape of the seat post tube  12 , can be of any conventional configuration. In the illustrated embodiment of the invention, the cross-sectional shape of seat post tube  12  is circular on both its interior and exterior. The cross-sectional shape of seat post may also be non-circular, and may include shapes such as ellipsoidal, square, rectangular, triangular, and higher order polygonal shapes. 
   The seat post  12  can be made from any strong, durable, and lightweight material including, for example, a composite material, aluminum, alloys, titanium, or other materials, and can be of any dimensions suitable for use with a bicycle. 
   In the method of the invention, there are two independent functions accomplished by engaging and the fastener driver  30  within the central aperture  28  of the adjusting member. Upon insertion of the rotating tool into the head  34  (shown in phantom in  FIGS. 2A and 2B ), rotation of the fastener driver  30  in the first direction (according to the arrow A) causes tightening connection between the bicycle seat, the seat post and the elongated adjusting member, so that the bicycle seat is fixed in a predetermined position. Simultaneously, tightening of the wedge sub-assembly  50  occurs resulted in fixing position of the seat post  12  within the bicycle frame. More specifically, during the rotational motion of the fastener driver  30  in the first direction, the wedge-shaped elements  18  and  44  are drawn against each other causing misalignments thereof within the interior of the tube receptacle  20 . As a result, frictional engagement of the wedge sub-assembly fixably attaches the seat post  12  at a predetermined elevation or angular position with the receptacle  20  of the frame  22 . 
   When the fastener driver  30  is rotated in the second direction (see the arrow B in  FIG. 2B ), a connection between the adjusting member  12 , the seat post  12  and seat  16  is loosened. This allows repositioning of the seat with respect to the seat post. Simultaneously, a wedging action between wedge-shaped elements  18  and  44  is loosened. Thus, the wedge-shaped elements  18  and  44  are aligned with respect to each other. This reduces friction between the wedging mechanism and to the interior of the frame, facilitating motion of the seat post  12  within the inner space of the frame receptacle  20 . 
   One of the essential features of the method of invention is that a single operational step which is based on a single integrated mechanism, is used not only for adjustment of the position of the seat  16  relative to the seat post  12  and the bicycle frame receptacle  20 , but also provides simultaneous adjustment of the seat post position relative to the bicycle frame receptacle. 
   Thus, the method and device of the invention do not require two independent mechanisms for angular adjustment of the seat with respect to the seat post and another mechanism for adjustment and fixation of the seat post within the bicycle frame. 
   The seat assembly  10  of the invention includes a minimum number of parts, which advantageously reduces manufacturing costs as well as labor costs associated with assembly. For example, reducing the labor costs associated with simultaneous adjusting of the seat assembly and seat post allows a bicycle shop or manufacturer to spend minimal time on these operations, and advantageously reduces overhead. Also, the reduced number of parts minimizes the weight of seat assembly  10 , and provides riders with further important competitive advantages. 
   By utilizing the device and method of the invention, an operator can easily adjust the angle of seat  16  and simultaneously elevate the seat post with respect to the bicycle frame by simply inserting an elongated wrench (not shown) through the slit in the seat  16  to engage and rotate the fastener  30 , loosening the fastener and allowing re-positioning of the seat  16  so as to achieve a desired angle. At the same time, the wedge-shaped sub-assembly  50  is also being loosened allowing adjustment of the seat post within the bicycle frame  20  and  22 . When the fastener  30  is tightened, the seat  16  and support structure  14  are securely attached to the seat post  12  in the pre-selected position. Simultaneously, the seat post is fixed within the frame receptacle  20 .