Abstract:
A bicycle seat height adjusting assembly comprises of a seat post that axially slides into an insert sleeve that fits into a bicycle frame in the place of a conventional seat post. The front of the seat post has a plurality of evenly spaced holes sized to receive a locking pin. The locking pin with supplemental spring is positioned within a generally cylindrical protrusion that extends out from the top section of the insert sleeve. A main air spring is positioned within the seat post to keep the main air spring free from dirt interference, allow the post to fully rise and lower, and enable the use of a maximum height pre-adjustment system. The locking pin connects to a cable that extends out to an actuation lever that is positioned on the handlebars. The opening between the main air springs two chambers is sized to damped the airflow and keep the seat post from rising up too fast. The counter rotational system for the seat post is formed mainly in the insert sleeve to maintain a strong and conventional looking seat post.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates generally to a seat post that can be fully raised or lowered, particularly on a mountain bicycle while the cycle is in motion. 
         [0002]    While a bicycle seat is positioned higher, the seated cyclist is able to exert a greater amount of force on the pedals. Yet, the bicycle is vastly more maneuverable while the seat is down and out of the way. While riding on trails that are steep and challengingly bumpy, this lower seat position gives the cyclist a lower center of gravity, to avoid being thrown off the bike. An adjusting seat post assembly should therefore have the capacity to be fully adjusting. 
         [0003]    For the cyclist there is an exact seat height that yields the greatest amount of propulsion from the bicycle. A system that immediately positions the seat post into this personalized, exact maximum height will reduce the time and effort that would otherwise be spent making readjustments while riding the bicycle. 
         [0004]    A remote lever that is positioned on the handlebars is required for keeping the cyclist safely attached to the bicycle. A seat post adjusting system that requires the cyclist to remove one hand from the handlebars while riding over bumpy terrain would possibly cause the cyclist to loose control of the bicycle. 
         [0005]    A bicycle seat post needs to be strong and lightweight relative to the added performance that a seat post or any other bicycle component may bring to the bicycle. In the field of height adjusting seat posts, the seat post assembly should also be as light and strong as possible. 
         [0006]    Bicycling on trails of dirt and mud, an adjusting seat post assembly must be as dirt poof as possible to maintain the products reliability. 
         [0007]    There are a number of height adjusting seat posts designs that provide an upwardly urging spring mechanism and a post locking means. Yet, most of these designs are not capable of full adjustment and are limited in their range of operation. Use of a main air spring should also decrease weight and increase strength from having a generally tubular-type structure. 
         [0008]    An air sprung adjusting seat post should also have a lightweight air dampening system to keep the seat post from rising up too fast. Yet, the air sprung posts presented so far, all do not provide a fully capable, adjusting seat post. 
         [0009]    Zurfluh, U.S. Pat. No. 5,713,555, Hsu, U.S. Pat. App. No. 2009/0108642, Turner, U.S. Pat. No. 7,083,180 and McAndrews, U.S. Pat. App. No. 2009/0324327 all present main air spring seat post designs. Yet, they all simply position the seat post within the main insert sleeve to form a main air spring. These previous designs are extremely sensitive to dirt, as their air seals can be broken by any dirt that gets onto the seat post and is then lowered into the main insert sleeve. All these other systems, also do not include a lightweight air dampening system or have the capacity to access a personally adjustable maximum height set system for achieving a full span of height adjustment. 
       OBJECTS AND ADVANTAGES 
       [0010]    An object and unique advantage of the present invention is a seat post assembly that has a main inverted air spring that is positioned within the seat post to keep the air spring sealed and free from being impeded by dirt, which there is much of, often when mountain biking. 
         [0011]    Another object and unique advantage of the present invention is a seat post assembly that incorporates a full span air spring design that is able to maintain a very even spring rate while fully rising and fully lowering. This inverted, two chamber air spring design further enables the use of a lightweight air dampening system that keeps the seat post from rising up too fast. 
         [0012]    Another object and advantage of the present invention is a seat post assembly that utilizes a main air spring to provide a strong and lightweight adjusting seat post due to its high strength, tubular type structure. 
         [0013]    Another object and advantage of the present invention is a seat post assembly that has a full span and range of locking positions, from a fully lowered position for maximum control, a multitude of middle positions for varying degrees of terrain challenge and a maximum seat height position that provides the most power and efficiency from the bicycle. 
         [0014]    Another object and advantage of the present invention is a seat post assembly that incorporates a remote actuation lever that is positioned on the handlebars and therefore keeps the cyclist safely attached to the bicycle. 
         [0015]    Another object and advantage of the present invention is a seat post assembly that has a capacity to personally adjust the maximum seat height that the seat post can rise to. Leg length and general comfort are the main factors when an individual is determining the maximum height that they want their seat to go, as the maximum height that the seat post is set at is different for almost everyone. By placing the air spring device within the seat post, this air spring devise also allows for a unique ability to access the outside of the seat post, where a maximum height adjustment devise is therefore able to be used and adjusted. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a side elevational view of a bicycle equipped with a seat position adjusting assembly according to one embodiment of this invention; 
           [0017]      FIG. 2  is an enlarged sectioned side view of the seat post assembly illustrated in  FIG. 1 ; 
           [0018]      FIG. 3  is an enlarged horizontal cross-sectional view of  FIG. 2  taken on line  3 - 3 ; 
           [0019]      FIG. 4  is an enlarged horizontal cross-sectional view of  FIG. 2  taken on line  4 - 4 ; 
           [0020]      FIG. 5  is an enlarged horizontal cross-sectional view of  FIG. 2  taken on line  5 - 5 ; 
           [0021]      FIG. 6  is a front view of the seat post counter rotational device; 
           [0022]      FIG. 7  is a view similar to  FIG. 2  of another embodiment of the invention; 
           [0023]      FIG. 8  is an enlarged horizontal cross-sectional view of  FIG. 7  taken on line  8 - 8 ; 
           [0024]      FIG. 9  is an enlarged horizontal cross-sectional view of  FIG. 7  taken on line  9 - 9 ; 
           [0025]      FIG. 10  is a view similar to  FIG. 2  of another embodiment of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    Referring now to the embodiment of the invention shown in  FIGS. 1 through 6  thereof, a new seat height positioning assembly generally designated by the reference number  11  is shown in  FIG. 1  inserted into the seat tube  12  of a bicycle frame  14 . The adjustable seat height assembly  11  generally comprises a seat post  20  and an insert sleeve  22  that is mostly tubular in configuration. Extending outwardly from the upper portion of the insert sleeve  22  is a generally cylindrical protrusion  25  that contains a seat post locking pin  23  and supplemental spring  24 . The locking pin  23  is connected by a cable  26  to an actuating lever  15 . The actuating lever  15  is positioned on the bicycle handlebar  16 . The seat post positioning assembly  11  also comprises a main air spring  70 , a maximum height set screw  30 , and a counter rotational boss  35 . The seat  17  is clamped to the top portion of the seat post  20  through any conventional clamping method  18 . 
         [0027]    The insert sleeve  22  retrofits into a bicycle frame seat tube  12  in the place of a traditional seat post. The insert sleeve  22  has a slight collar  27  at the upper portion that acts to limit the sleeve  22  from sliding entirely into the bicycle frame seat tube  12 . A post clamp  19  is engageable around the seat tube  12  of the bicycle frame  14  for fixedly securing the insert sleeve  22  with respect to the seat tube  12 . 
         [0028]    The seat post  20  is adjustable up and down, being telescopically slidable within the insert sleeve  22 . The seat post  20  is tubular in configuration as defined by a first inner wall  21 . A second tubular structure  60  is positioned mainly within the first inner wall  21  of the seat post  20 . A support disk  62  has a central opening  63  that fits onto the bottom of the second tubular structure  60 . The support disk  62  is attached to the sleeve inner wall  29  of the insert sleeve  22  within the lowest section of the insert sleeve  22 . An air valve  66  is positioned within the bottom section of the second tubular structure  60 . The air valve  66  extends below the support disk  62 , where it is capable of receiving pressurized air from an air pump type device. A perimeter air seal  65  is positioned around the top perimeter of the second tubular structure  60 . The perimeter air seal  65  creates a seat post  20  first air chamber  61  that is positioned above the perimeter air seal  65  and also creates a second air chamber  67  that is the inner area of the second tubular structure  60 . Air that is pumped into the second air chamber  67 , through the air valve  66 , will travel out the top end of the second air chamber  67  and be further contained within the first air chamber  61  of the seat post  20 . As the air pressure increases within the first air chamber  61  and the second air chamber  67 , the pressurized air pushes up on the top surface of the first air chamber  61 , to therefore form a main air spring  70  that urges the seat post  20  to rise. 
         [0029]    An air damper opening  69  is formed at the top of the second tubular structure. The air damper opening  69  is sized generally small enough to slow the air flow between the first air chamber  61  and the second air chamber  67 . The air damper opening  69  will restrain the seat post  20  from rising too fast. 
         [0030]    A wiper seal  38  is positioned around the sides and back of the seat post  20 . The wiper seal  38  fits into a wiper groove  39  that is formed around the sleeve inner wall  29  of the top section of the insert sleeve  22 . The wiper seal  38  will shed mud off the seat post  20  and keep mud from entering into the insert sleeve  22 . 
         [0031]    A counter rotational boss  35  is used to contain the seat post  20  from rotation. An inner channel  28  defined by spaced parallel walls  42 , 42 , is formed longitudinally along the sleeve inner wall  29  of the insert sleeve  22 . The inner channel  28  is formed in the lower three quarters of the insert sleeve  22 . The counter rotational boss  35  is attached to the bottom front side of the seat post  20  by the use of two screws  36 , 36  that tighten into the seat post  20 . The counter rotational boss  35  slides within the inner channel  28 . The counter rotational boss  35  is then contained against rotation by the parallel walls  42 , 42  of the inner channel  28 . Two stabilizing leaf springs  37 , 37  extend up from the counter rotational boss  35 . The two stabilizing leaf springs  37 , 37  continuously press against the parallel walls  42 , 42  of the inner channel  28  to stabilize the seat post  20  and firm up any amount of play between the counter rotational boss  35  and the parallel walls  42 , 42  of the inner channel  28 . An access opening  48  is formed through the insert sleeve  22  at the top section of the inner channel  28 . The access opening  48  is used firstly to gain access to the seat post  20  so that the counter rotational boss  35  can be attached. 
         [0032]    The maximum height set screw  30  is used to set the seat post  20  at a maximum seat height limitation. Formed longitudinally along the front of the seat post  20  is a rack of post holes  50 . The post holes  50  have threads  51  to enable the maximum height set screw  30  to be tightened within one of the post holes  50 . The maximum height set screw  30  also uses the access opening  48  to gain access to the post holes  50 . The maximum height set screw  30  has screw threads  31  formed in the portion that is positioned within one of the post holes  50 . A portion of the maximum height set screw  30  extends into the area of the inner channel  28  after the maximum height set screw  30  is fully tightened within one of the post holes  50 . The maximum height set screw  30  stops the upward motion of the seat post  20  upon the outermost portion of the maximum height set screw  30  being limited by the top surface of the inner channel  28 . 
         [0033]    The minimum height set screw  32  is used to set the seat post  20  at a minimum seat height limitation. The minimum height set screw  32  also has screw threads  33  formed in the portion of the minimum height set screw  32  that is positioned within one of the post holes  50 . The minimum height set screw  32  is tightened within one of the exposed upper post holes  50 . As the seat post  20  is lowered, the minimum height set screw  32  will stop the seat post  20  from lowering, upon engaging the top surface of the insert sleeve  22 . 
         [0034]    The locking pin  23  and supplemental spring  24  are slidably receivable within an inwardly open bore  41  that is formed within the generally cylindrical protrusion  25  of the insert sleeve  22 . The supplemental spring  24  is positioned between the end platform  43  of the inwardly open bore  41  and the locking pin  23 . The inwardly open bore  41  is set in alignment with the receiving post holes  50 . The locking pin  23  is forced into one of the post holes  50  by the supplemental spring  24  to lock the seat post  20  at a given height. A second bore  44  extends through the generally cylindrical protrusion  25 . The second bore  44  is sized to allow the cable  26  to pass through. A third bore  45  is formed in the outermost section of the generally cylindrical protrusion  25 . The third bore  45  is outwardly open with an inner end platform wall  46 . The third bore  45  is sized to have a portion of the cable housing  47  positioned within it. 
         [0035]    When the cyclist pulls the actuation lever  15 , the locking pin  23  is pulled into its open position shown in broken lines in  FIG. 3 . The locking pin  23  is therefore disengaged from one of the post holes  50  and the seat post  20  is urged upward by the force of the main air spring  70 . After adjusting the height of the seat post  20  with the cyclists buttocks the cyclist releases the actuation lever  15 , allowing the supplemental spring  24  to return the locking pin  23  to the locked position. Shown in  FIG. 3  is the locking pin  23  positioned into one of the seat post  20  locking holes  50 . 
         [0036]    FIG.  7 , 8 , 9  is the same as the embodiment in  FIG. 1-6 , with a few exceptions. The counter rotational boss  35  is replaced by an insert sleeve boss  34 . The insert sleeve boss  34  is positioned along the sleeve inner wall  29  of the insert sleeve  22 . The inner channel  28  is replaced by a longitudinal slot  52 . The longitudinal slot  52  is formed through the insert sleeve  22 . The insert sleeve boss  34  is positioned directly above the longitudinal slot  52 . A main groove  53  is formed longitudinally along the front of the seat post  20 . The post holes  50  are formed respectively along the back wall  54  of the main groove  53 . The insert sleeve boss  34  extends into the main groove  53  to thereby limit the seat post  20  against rotation. The maximum height set screw  30 , that is positioned within one of the lower post holes  50 , stops the upward motion of the seat post  20  upon engaging the insert sleeve boss  34 . The minimum height set screw  32  is replaced by the top surface  55  of the main groove  53 . The top surface of the main groove  53  therefore stops the seat post  20  from lowering, upon engaging the top surface of the insert sleeve boss  34 . A boot type cover  40  is shown in  FIG. 7  being attached around the top section of the seat post  20  and secondly attached around the top section of the insert sleeve  22  to completely seal out dirt and mud from getting into the insert sleeve  22 . 
         [0037]    An air gate  56  is shown in  FIG. 7 , that is used in addition to the air damper opening  69 , to let air pass from the first air chamber  61  to the second air chamber  67  without dampening the linear movement of the seat post  20 . The air gate opening  57  is positioned through the top surface of the second tubular structure  60 . The air gate  56  is made of a rubber like material that forms a flexible hinge  58  that pivots a cover seal  59  for the air gate opening  57 . The air gate  56  is shown in  FIG. 7  in a generally closed position. The air gate  56  is shown in its open position in broken lines. The air gate  56  is opened by the downward movement of air that travels from the first air chamber  61  and passes through the air gate opening  57  to go into the second air chamber  67 . The air gate  56  is opened while the seat post  20  is being lowered and closes as the seat post  20  rises. 
         [0038]      FIG. 10  is the same as the embodiment in  FIG. 1-6 , with a few exceptions. A third tubular structure  71  that has a closed top end and an open bottom end is positioned within the first inner walls  21  of the seat post  20 . The second tubular structure  60  is positioned within the third tubular structure  71 . The perimeter air seal  65  positioned around the second tubular structure  60  forms an air tight seal between the third inner wall  74  of the third tubular structure  71  and the perimeter air seal  65  to form a third air chamber  76  in the place of the first air chamber  61 . 
         [0039]    The pressurized air within the third air chamber  76  also flows into the second air chamber  67  of the second tubular structure  60  to form a removable air spring assembly  80 . 
         [0040]    The locking pin  23  in  FIG. 10  is shown in the unlocked position. The locking pin  23  is shown in the locked position in broken lines.