Abstract:
A bicycle seat tube assembly includes an arced component, a bottom bracket positioned below the arced component, and a seat tube including a pivot attachment at a lower end of the seat tube. The arced component includes a lower curved surface with a plurality of holes. The pivot attachment is coupled to the bottom bracket so that the arced component is pivotable relative to the seat tube about the bottom bracket, resulting in multiple seat tube positions between a fully forward position and a fully back position. A locking mechanism is configured to selectively lock the seat tube to the arced component. The locking mechanism includes a lock ring with a plurality of lock pins and a spring that pushes the lock ring towards the arced component. The lock ring and the spring surround the seat tube The lock ring is movable between a locked position and an unlocked position.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application claims priority from U.S. Provisional Application No. 61/687,926, filed May 4, 2012, which is incorporated herein by reference in its entirety. This application claims priority from U.S. Provisional Application No. 61/743,635, filed Sep. 10, 2012, which is incorporated herein by reference in its entirety. This application claims priority from U.S. Provisional Application No. 61/851,061, filed Mar. 1, 2013, which is incorporated herein by reference in its entirety. This application claims priority from U.S. Provisional Application No. 61/791,585, filed Mar. 15, 2013, which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     The present invention relates generally to the field of seat assemblies and frames for bicycles and the like. 
     SUMMARY 
     One embodiment relates to a bicycle seat tube assembly including an arced component, a bottom bracket positioned below the arced component, and a seat tube including a pivot attachment at a lower end of the seat tube. The arced component includes a lower curved surface with a plurality of holes. The pivot attachment is coupled to the bottom bracket so that the arced component is pivotable relative to the seat tube about the bottom bracket, resulting in multiple seat tube positions between a fully forward position and a fully back position. A locking mechanism is configured to selectively lock the seat tube to the arced component at one of the seat tube positions. The locking mechanism includes a lock ring with a plurality of lock pins and a spring that pushes the lock ring towards the arced component. The lock ring and the spring surround the seat tube The lock ring is movable between a locked position in which the lock pins are inserted into the holes and an unlocked position in which the lock pins are removed from the holes and the arced component is free to pivot about the bottom bracket. 
     Another embodiment relates to a bicycle frame including a head tube configured to receive a handlebar, a bottom bracket, a down tube extending rearward and downward from the head tube to the bottom bracket, a top tube extending rearward from the head tube, an arced component including a forward end coupled to the top tube and a lower curved surface with a plurality of holes, and a seat tube including a pivot attachment at a lower end of the seat tube. The pivot attachment is coupled to the bottom bracket so that the arced component is pivotable relative to the seat tube about the bottom bracket, resulting in multiple seat tube positions between a fully forward position and a fully back position. A locking mechanism is configured to selectively lock the seat tube to the arced component at one of the seat tube positions. The locking mechanism includes a lock ring with a plurality of lock pins and a first spring that pushes the lock ring towards the arced component. The lock ring and the first spring surround the seat tube The lock ring is movable between a locked position in which the lock pins are inserted into the holes and an unlocked position in which the lock pins are removed from the holes and the arced component is free to pivot about the bottom bracket. A second spring is coupled between the head tube and the seat tube to pull the seat tube towards the fully forward position. The second spring is located within the top tube. 
     Another embodiment relates to a bicycle including a frame including a head tube, a top tube extending rearward from the head tube, an arced component having a forward end coupled to the top tube and a lower curved surface with a plurality of holes, and a bottom bracket positioned below the arced component and a seat tube including a pivot attachment at a lower end of the seat tube. The pivot attachment is coupled to the bottom bracket so that the frame is pivotable relative to the seat tube about the bottom bracket, resulting in multiple seat tube positions between a fully forward position and a fully back position. A locking mechanism is configured to selectively lock the seat tube to the arced component at one of the seat tube positions. The locking mechanism includes a lock ring with a plurality of lock pins and a first spring that pushes the lock ring towards the arced component. The lock ring and the first spring surround the seat tube The lock ring is movable between a locked position in which the lock pins are inserted into the holes and an unlocked position in which the lock pins are removed from the holes and the frame is free to pivot about the bottom bracket. A second spring is coupled between the head tube and the seat tube to pull the seat tube towards the fully forward position. The second spring is located within the top tube. A saddle is movably coupled to the seat tube so that the saddle is adjustable up and down relative to the seat tube. A front wheel is coupled to the frame, a rear wheel is coupled to the frame, and a handlebar is coupled to the head tube. With the lock ring in the unlocked position, the seat tube remains stationary and the frame pivots to follow the terrain on which the bicycle is being ridden 
     Other embodiments relate to a bicycle frame where the seat tube assembly remains in a fixed position with respect gravity and the riders&#39; most efficient body position and the remainder of the frame assembly is allowed to rotate about the bottom bracket. In some embodiments, the frame includes an arced component that is designed so that it guides the seat tube assembly within its range and provides a radiused surface to mount removable insert strips. In some embodiments, insert strips are designed using non concentric radii so that one arc design can be used for any size bicycle frame. The insert strips may have slotted positioning pockets that accept stepped and tapered locking pins and allow the pins to be misaligned in frame assembly without compromising the stability of the locking mechanism. The insert strips may have an inside wall that can be precision fitted to the seat tube flats maintaining a slip fit required for accurate and sustained locking of the frame/seat tube relation. The seat tube assembly may be integrated with a remotely controlled hydraulic seat post assembly that allows the rider to raise and lower the saddle independently or in conjunction with the rotation of the frame. In some embodiments, the frame assembly uses an extension spring or optional hydraulic assembly to pull the frame towards the fixed seat tube assembly when the rider chooses to adapt the frame geometry for any terrain conditions they encounter (e.g. up or down hill) or to benefit the rider&#39;s bio mechanical position. 
     Other embodiments relate to a fixed seat tube assembly and locking mechanism that provides a way for the saddle to remain fixed while the rest of the frame and associated wheels, etc to follow the terrain thus allowing the rider to maintain their maximum power position by virtue of not moving with respect to gravity and their predetermined power position. 
     Other embodiments relate to a fixed seat tube assembly and locking mechanism that allows a rider to fine tune their riding position by pulling or pushing the frame toward or away from the fixed seat tube assembly. In some embodiments, a cable or hydraulic assembly allows the rider to disengage the frame from the seat tube assembly as the rider determines using a control typically mounted on the handlebars. The cable assembly may include a mechanical advantage design that lessens the required on the thumb lever. A lock ring may be disengaged and engaged by the cable assembly in a symmetrical and even force based on the cable pulley system. A coaxial mounted extension spring may be housed inside the top tube and damped by a tube liner that pulls the frame toward the fixed seat tube or allows the frame to move freely fore and aft of the fixed seat tube as desired without the need of the rider to push or pull in order to change the frame/seat tube relationship. In some embodiments, a frame design made up of “V” shaped tubes extending from each end of the arc to the bottom bracket to form a solid structure maintains the integrity of the locking mechanisms. In some embodiments, an eccentric bushing where the rear axle passes allows for the precise rear wheel alignment to the arc leading to a shorter overall wheelbase. In some embodiments, a spring steel or hard bearing material lower bottom bracket strap holds the seat tube assembly against the bottom bracket while allowing a smooth pivot point for the frame to rotate with respect to the fixed seat tube. A second spring steel or hard bearing material may be sandwiched between the bottom bracket and the seat tube assemblies&#39; lower yoke providing a hard running surface between the typically softer frame materials. A shock absorbing and height adjusting assembly may be used, allowing for precision adjusting of the head tube angle and shock relief of the front section of a frame. In some embodiments, a spring retainer ring allows for the tension adjusting of the compression spring that pushes the locking ring with it&#39;s pins up into the insert strips. Locking pins designed with a taper as well as a step may be used to allow for fast and accurate insertion in and out of their slotted receptacle pockets. As the pins seat their tapered lower section is forced to wedge into the insert strips creating a solid fit that mimics the weld used on a traditional bike 
     Another embodiment relates to a method for riding or racing a bicycle that uses physics and adaptable frame geometry design to provide a way for a rider to maintain their most powerful and/or most comfortable position by allowing the seat tube assembly to remain fixed with respect to gravity and a riders&#39; leg/body position while the remaining frame geometry is allowed to pivot about the bottom bracket at the direction of the rider thus adapting to various terrain conditions e.g. up or down hill. If it has been determined that a rider&#39;s most efficient power position with respect to the frame geometry on flat ground then changing the terrain would not alter that ultimate position. Because a traditional bicycle frame is “fixed” it stands to reason that the most efficient position is diminished when any terrain other than flat is encountered. The method described here allows for the rider to maintain that most efficient position by keeping the seat tube fixed with respect to gravity and the riders&#39; body position while encountering variable terrain. 
     Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a bicycle according to an exemplary embodiment; 
         FIG. 2  is a perspective view of a bicycle according to an exemplary embodiment; 
         FIG. 3  is a perspective view of the bicycle of  FIG. 2  on flat ground; 
         FIG. 4  is a perspective of the bicycle of  FIG. 2  going up a moderate hill; 
         FIG. 5  is a perspective of the bicycle of  FIG. 2  going up a steep hill; 
         FIG. 6  is a perspective of the bicycle of  FIG. 2  going down a steep hill; 
         FIG. 7  is an exploded view of a bicycle frame according to an exemplary embodiment; 
         FIG. 8  is an exploded view of a bicycle frame according to an exemplary embodiment; 
         FIG. 9  is an exploded view of a bicycle frame according to an exemplary embodiment; 
         FIG. 10  is a perspective view of a portion of a bicycle frame, with some components omitted for clarity; 
         FIG. 11  is an exploded view of an arced component of a bicycle frame according to an exemplary embodiment; 
         FIG. 12  is a bottom perspective view of an arced component of a bicycle frame according to an exemplary embodiment; 
         FIG. 13  is a perspective view of a portion of a bicycle frame according to an exemplary embodiment; 
         FIG. 14  is a perspective view of a portion of the bicycle frame of  FIG. 13 ; 
         FIG. 15  is a perspective view of a portion of the bicycle frame of  FIG. 13 ; 
         FIG. 16  is a perspective view of a portion of the bicycle frame of  FIG. 13 , with some components omitted for clarity; 
         FIG. 17  is a perspective view of a portion of the bicycle frame of  FIG. 13 , with some components omitted for clarity; 
         FIG. 18  is an exploded view of a portion of the bicycle frame of  FIG. 13 ; and 
         FIG. 19  is a perspective view of a portion of a bicycle according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. 
     As shown in the Figures, a bicycle frame  100  as described herein addresses the problem that all riders have when they encounter changing terrains while riding. The typical bike frame is primarily designed to be used most efficiently on flat terrain. Even if a frame is custom fitted to a specific rider it is done based on flat ground. The fact that a seat tube on industry standard frames is fixed at a particular angle (typically between 70 and 74 degrees) is an admission that it is an “average” of all terrains that it will encounter. The bicycle frame  100  provides a seat tube  105  that can be indexed on the fly at varying angles depending on the riders&#39; requirements. This means that a rider can quickly move and lock (index) the seat tube  105  to a position that provides them with the greatest efficiency at that moment during the ride. This is due to the fact that there is one physical position for any given rider that produces the greatest power to the cranks  110  and that position changes as the terrain changes. 
     An exemplary embodiment of a bicycle  115  including the frame  100  is illustrated in  FIGS. 1-2 . As shown in  FIG. 2 , the frame  100  includes a head tube  245 , a top tube  215 , a down tube  275 , the seat tube  105 , a bottom bracket  140 , an arced component  180 , four support struts  230 , a seat stay  117 , and a chain stay  119 . A front wheel  121  is supported by a suspension fork  123 . The front wheel is braked by a disc brake  127 . The handlebars  310  include a stem  129 . A drop out  131  allows a rear wheel  133  to be removed from the frame  100 . The seat  135  is supported by a seat post  137  and secured by a seat post clamp  139 . 
     The method that allows the rider to change the riding position is built into the design of the frame  100 . This method must be practical and safe for it to become a realistic standard in the bicycle industry. The following steps are used to provide the “method” that the frame  100  and bicycle  115  use to obtain maximum efficiency. The rider traveling on a road or trail uses a thumb lever  120  to release a locking mechanism  125  that holds the pivoting seat tube  105  in place (step 1). The seat tube  105  is spring loaded forward by a spring  130  so that it is easily positioned by the rider even when moving uphill (step 2). As the rider encounters a particular terrain, he or she unlocks and positions the seat tube  105  to the position that they determine to be the most efficient or comfortable (step 3). When the thumb lever  120  is released the locking mechanism  125  latches to secure the seat tube  105  (step 4). The ability of the rider to quickly and positively position themselves at their most efficient or comfortable location provides the method for maximum riding performance. 
     For reference,  FIGS. 5-6  show the positions of the frame  100  with respect to the fixed seat tube  105  at the limits of its range.  FIG. 3  shows the frame  100  with the bicycle  115  on flat ground and the seat tube  105  at a mid range position.  FIG. 4  shows the frame  100  with the bicycle going up a moderate hill and the seat tube  105  at a partially forward position.  FIG. 5  shows the frame  100  with the bicycle  115  going up a steep hill and the seat tube  105  at a fully forward position.  FIG. 6  shows the frame  100  with the bicycle  115  going down a steep hill and the seat tube  105  at a fully back position. Note that the seat  135  and seat tube  105  remain fixed while the frame  100  pivots about the bottom bracket  140  compensating for the change in terrain. 
     Various exemplary embodiments of the frame  100  are shown in exploded views in  FIGS. 7-9 . The bicycle frame  100  (mountain, city, road, triathlon, beach, etc) includes an integrated seat tube assembly  145  based on the ability for the seat tube assembly  145  to index into the best and/or most efficient position as determined by the rider during operation. The seat tube  105  is released, indexed, and locked into place by an assembly and mechanism  125  designed specifically to hold solid the assembly  145  while riding the bicycle  115 . The locking mechanism  125  is designed to “wedge” into place so that a locking ring  155  and pins  160  (shown in  FIG. 10 ) do not slip or move during the bicycle&#39;s operation. The locking mechanism  125  is operated via a cable release lever  120  conveniently located to the rider. The seat tube assemblies&#39; lower connection  165  pivots around the centerline axis of the bottom bracket  140  so that the height of the seat  135  does not change during or after the indexing operation is performed. The upper bottom bracket clamp half  170  is held in place with a spring steel lower clamp  175  that allows for the smooth indexing of the seat tube  105 . As shown in  FIG. 9 , a remotely controlled hydraulic seat post assembly  177  allows the rider to raise and lower the saddle  135  independently or in conjunction with the rotation of the frame  100 . An eccentric bushing  179 , where the rear axle passes, allows for the precise rear wheel alignment to the arc  180 , leading to a shorter overall wheelbase. 
     As shown in  FIGS. 11-14 , the bicycle frame  100  includes an arced component  180  that furnishes the seat tube locking pins  160  a matching radius for the latching. A spring  185  is slid onto a ring  190  and clamped in place along the seat tube  105  and pushes the locking ring  155  and pins  160  upward engaging holes  195  in the underside of the arc, thus holding the seat tube assembly in place until released again by the rider to another position along the arc  180 . The seat tube  105  can index into holes  195  laid out along the underside of the arc  180  approximately every 2 degrees for the length of the arc  180 . Tapered locking pins  160  are used so that when the lock ring  155  is pushed into the mating holes  195  in the bottom of the insert strips  200 , the lower taper of the pins  160  will wedge into the holes  195  creating a solid hold so that the seat tube  105  does not wiggle when the bike  115  is ridden. 
     Different bicycle styles (e.g. mountain, road) may use arcs  180  of different lengths and radii depending on the design criteria of the particular frame. The underside of the arc  180  may include an insert  200  of a harder material for the locking pins  160  to increase the life of the locking mechanism  125 . A pull force reducing pulley mechanism  205  (including cables  207  and  209 ) is used to lessen the force necessary to release the pins  160  from the arc  180 . The cable or hydraulic release mechanism  300  is designed so that there is equal and symmetrical pull on the lock ring  155  to insure positive locking of the pins  160 . Slide inserts may be used on some models inside the arc&#39;s surfaces to lessen the friction between the seat tube  105  and the arc  180 . When released the seat tube  105  is pulled toward the front of the bicycle using a spring and cable assembly  210  located inside a top tube  215  of the frame  100 . The frame  100  may be made using a variety of state of the art materials, and the design is not dependant on any single material. The frame  100  accepts additional industry standard bicycle components typically used to make up the completed bicycle  115 . 
       FIGS. 11 and 12  illustrate the arc  180 . The arc body  181  is formed of two halves  183  and  187 . The halves  183  and  187  are pinned and bolted together. The halves  183  and  187  can be cast with better precision. The arc  180  defines a tube guide slot  189 . The radius plate modules or inserts  200  are made from a hard material like titanium or silicon carbide, eliminating the need for pressed in steel strips. The bottom radius  191  of the insert  200  is changed for different bike sizes. The radius  191  determines the size of the bike (e.g., a 16″ radius results in a 16″ bike). The top radius  193  of the insert  200  matches the inner radius of the arc body  181 . The inserts  200  are removable. The arc body  181  is the same for all bikes (e.g., for all mountain bike sizes) because the inserts  200  are matched to the bike size. Locking holes  195 , slots, or teeth are formed in the insert  200 . The inserts  200  also include mounting holes  197  and registration slots  199 . 
     One of the main components of all of the bikes is the arced component  180  at the top of the indexing seat tube assembly and mechanism. The arc  180  may be made in modular sections that allow for easier manufacturing and design flexibility. The arced section  180  is used as a guide for the seat tube  105  and maintains a tight fit of all the locking components. The lower module  200  that contains the radius where the locking ring  155  attaches may be made so that it can be replaced if damaged without the need to replace the entire arc  180 . This module  200  may be made of a stronger material such as steel, titanium, or silicon carbide that eliminates the need for a pressed in insert into the bottom of the arc  180  for rigidity of the locking mechanism  125 . The radius plates  200  are further used to allow one arc size to fit all bike sizes with only the need to use the correct radius plate  200  to match the size bike being built. The radius plates  200  contain the index holes  195  or teeth that accept the pins  160  or teeth of the lock ring  155 . If the radius plates  200  are damaged or worn only they need to be replaced instead of the entire arc  180 . 
     A removable insert strip  200  that attaches to the underside of the arc  180  allows for the arc  180  to be the same for all size bikes. The different size insert strips  200  have a top radius that is always the same and match the bottom radius of the arc  180  but a lower radius that varies depending on the size bike it is being used with. Because the various bike sizes require that the final bottom radius of the arc&#39;s insert strip  200  where the lock mechanism  125  slides is a set distance from the middle of the bottom bracket  140  (e.g. 17″ radius for a 17″ frame), it is efficient to have a design where the same arc body  181  can be used for all bikes. The range of the seat tube movement within the arc  180  may be controlled with stops or the dimensions of the arc  180 . 
     As shown in  FIG. 13 , the seat tube  105  uses machined flats  220  about the tube  105  that keep the locking ring  155  from rotating or twisting during operation. A visco-elastic shock dampening material or pad  225  is mounted in a location between the spring loaded seat tube assemblies locking mechanism  125  and a forward arc structure  230  to protect the user or any person from potential injury. The lock pins  160  may be slightly offset so that they are forced into a wedging connection into the arc&#39;s lower mating holes  195 . This will hold the locking mechanism  125  in a much tighter bond. The clamp  190  is used to adjust the tension of the push up spring  185 . The V shaped support struts  230  add rigidity to the entire frame  100  as well as support and stability to the arc  180 . As shown in  FIG. 15 , a bracket  235  that accommodates a bicycle industry standard front derailleur  240  is mounted between the right side V supports  230  in a way that allows for the seat tube  105  to move freely. If a front derailleur  240  is required, it is designed with an open lower cage  320  that allows the chain  325  to move without contact. This derailleur design also allows for its removal from the frame  100  without the need to separate the chain  325 . 
     As shown in  FIG. 9 , a threaded insert  150  located at the bottom of a head tube  245  that allows fine tuning of the head tube length for proper fit of the fork  250  into the head tube  245 . This insert  150  can also be used to change the angle of the head tube  245  with respect to level ground. A shock absorbing cartridge may be integrated into the head tube adjustment ring  150  of road or triathlon bike frames to control fatigue of the front sections of the frame  100  as well as the rider&#39;s upper body. 
     As shown in  FIG. 16 , the seat pull spring assembly  210  is mounted coaxial with the top tube  215  so that it can be pulled back and forth as required. The assembly  210  is anchored (e.g., by a flat head bolt  255 ) to the head tube  245  for maximum stability. The assembly  210  is covered with a plastic or rubber material tube liner  260  to lessen noise during use. The assembly  210  is anchored to the seat tube  105  via a quick release wire or cable  265  around the circumference of the seat tube  105 . The quick release wire  265  forms a wire loop  267  and cable stop  269 . The quick release wire  265  is coupled to the seat tube pull spring  130   
     As shown in  FIG. 17 , a down tube yolk  270  is used to attach the down tube  275  to the bottom bracket  140  in a way that allows for clearance for the seat tube  105  to arc forward without obstruction. The seat tube pivot attachment  165  is attached to the bottom bracket  140  using a spring steel band  175  that allows for a smooth rotation of the seat tube assembly around the bottom bracket  140 . The surfaces of the rotating parts can be easily lubricated through the opening at the top of the seat tube  105 . A hardened steel, copper, or other bearing material  315  is used around the diameter of the bottom bracket  140  so that the lower clamping bracket  175  rides on a hardened surface acting as a bearing to prevent wear and noise. 
     The road bikes (that includes the triathlon bike) use a cable seat release  290  (as shown in  FIG. 19 ) instead of the thumb release  120  used on mountain bikes (e.g., as shown in  FIGS. 1-2 ). The seat release cable  290  is an extension of the main cable  300  and spans between the curved sections  305  of the handlebars  310  with stops at the required positions. As shown in  FIG. 19 , for a bike with a road style drop handlebar  310 , the lock ring release mechanism can be actuated using an extension  290  of the pull cable  300  that spans between two sections  305  of the bar  310 . 
     Integrated into the seat tube assembly  145  is a hydraulic drop seat assembly  330  that may be used independently or simultaneously with the pivoting seat tube  105  to raise or lower the seat  335  as desired by the rider. 
     Because the bike frame  100  and seat tube assembly  145  are separate, the seat tube assembly  145  can maintain a fixed position with respect to gravity and the riders&#39; body position while the rest of the frame  100  pivots at the bottom bracket  140  when desired. Because the seat tube assembly  145  can remain stationary while the remainder of the bike  115  follows the terrain, the rider maintains their maximum power position. 
     The construction and arrangement of the elements of the apparatus as shown in the exemplary embodiments are illustrative only. Although only a few embodiments of the present disclosure have been described in detail, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements. The elements and assemblies may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Additionally, in the subject description, any use of the word “exemplary” is used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word “exemplary” is intended to present concepts in a concrete manner. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the preferred and other exemplary embodiments without departing from the scope of the appended claims. 
     The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating configuration, and arrangement of the preferred and other exemplary embodiments without departing from the scope of the appended claims.