Abstract:
The present invention allows a user to mount/dismount a bicycle wheel in a single motion. An outer shell contains a single cam operated by an external lever. One feature of the cam is a detent that, when the cam is rotated to the proper position and pulled back, mates with a shoulder to effectively lock the skewer shaft in place. Upon rotation of the lever, the internal cam is pulled to the locked position where the wheel will clear impediments on a bicycle frame or fork without any additional manipulation.

Description:
[0001]    This non-provisional application for patent claims priority under 35 USC 119(a) based on U.S. provisional application No. 61/401,224 filed Aug. 9, 2010. 
     
    
     BRIEF DESCRIPTION 
       [0002]    The subject of this invention relates to the bicycle industry. More specifically, the disclosed invention teaches a novel and improved wheel mounting skewer release mechanism where the improvement is a single acting internal cam that allows the user to mount or dismount the wheel without the need to adjust the skewer and advantageously locks the release lever in place greatly simplifying the wheel changing process and significantly improving rider safety. A single motion of the release lever moves both ends of the improved skewer outward so that sufficient clearance is provided to clear the front fork safety tabs. Moreover, should the release lever be inadvertently loosened, an internal spring maintains pressure on the moving parts of the release mechanism such that the wheel stays properly mounted. 
       BACKGROUND OF THE INVENTION 
       [0003]    Bicycles have existed for many years. In 1817 in its earliest incarnation, the bicycle was a simple set of two same sized in-line wheels, the front wheel steerable. The user straddled the apparatus and moved it forward with his feet. This apparatus, also known as a hobby horse, was invented by Baron von Drais to assist him in moving about his estate gardens. 
         [0004]    In 1865 the first pedal propelled bicycle appeared, called a velocipede. Also referred to as a bone-shaker, this apparatus had pedals on the front wheel which was also used to steer. Then, about 1870 the classic high wheel apparatus, the first to be called a bicycle, appeared on the scene and enjoyed great popularity. From this point, in a fairly straight line of descendentcy, the modern bicycle has emerged. Advances in material science, chiefly metallurgy, and more recently, composite material science, have created more efficient, stronger and higher performing bicycles. 
         [0005]    One feature that has not changed in over one hundred years is the basic mechanical configuration of a bicycle. Generally the user mounts the apparatus and applies pressure to a pair of pedals. These pedals are attached to crank arms which drive a chain. The chain receives power input from a pedal crank that has a motive force exerted upon it from a rider&#39;s legs. The force is transferred by the chain to the driven wheel by a geared cog, for example, which is in turn mechanically linked to a hub. The hub is attached to the drive wheel by means of spokes or solid inserts such as in the so-called disk wheels. In this way linear force from a rider&#39;s legs is transformed to rotational force applied to the wheel and then to the road surface. 
         [0006]    In the case of the front wheel, no driving components exist. The front wheel simply fits into a pair of lugs on the end of the front forks. The methodology used to mount/dismount the wheel is the same, thus a discussion of either the front or the rear wheel will suffice. It is worth mentioning that there is a type of bicycle referred to as a “recumbent” that can have a front wheel drive configuration, but as those of skill in the art will recognize, the mounting methods remain the same. 
         [0007]    Whether a front or rear wheel, and regardless of the method used to fix the wheel to the frame, lugs are used to receive the axel. Many types of lugs are in use with just as many configurations. Some are horizontal with a front opening, some horizontal with a rear opening and some are vertical, either top or bottom loaded. Regardless of the type of lug used, the method of fixing the wheel to the frame of the bicycle remains the same, thus any type of lug may be used in a discussion without consideration of a specific type. In the discussion that follows, a vertical lug with a down-facing opening is used, but the methods discussed could be used with any type of lug configuration. 
         [0008]    From time to time the wheels must be detached from the bicycle frame, for example, to change a flat tire or to replace a worn part. There exist many contemporary methods for attaching the wheel to the bicycle frame. One method uses a solid axle threaded on both ends. Once the axle ends have been located correctly in the frame lugs, axel nuts are tightened to fix the wheel in place. A second method uses a hollow axle through which a rod, or so called skewer, is run. One end of the skewer has a lever and the other end an adjustable nut. Once the wheel is in the correct position the lever is operated which results in a clamping force to fix the wheel in place. 
         [0009]    While these methods are functional, they suffer from a common flaw. Modern bicycles have safety features which force the user to manipulate the axel or skewer considerably in order to remove the wheel from the frame. In the case of the front wheel, a pair of safety tabs exist that are used to keep the wheel from separating from the frame if the axel or skewer becomes loose. In the case of the rear wheel, the lugs that receive the axel or skewer tend to interfere with wheel removal. In both cases, contemporary wheel mounting schemes fail to provide the needed clearance to drop away from the frame lugs without manipulation. Once the wheel is clear, maintenance can occur, but the same problems exist upon remounting of the wheel. 
         [0010]    A second major problem with prior art methods is that the derailleur, usually located on the rear wheel, is very delicate. The derailleur is the devise that moves the chain inward or outward to select one of a plurality of cogs in order to increase or decrease speed. If the user inadvertently applies a force in the wrong place, for example, while manipulating axel nuts or the skewer nut, the alignment of the derailleur box could be adversely affected. 
         [0011]    What would be desirable is an apparatus that eliminates the need for the user to manipulate the axel or skewer. What would be additionally desirable is an apparatus that improves the safety of a rider. The apparatus of the present invention provides an improved wheel skewer that accomplishes these goals as well as eliminating other problems related to the prior art methods discussed above by providing a single motion that moves both ends of the skewer outward at the same time yielding sufficient clearance to dismount/mount a wheel without additional manipulation. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention allows a user to mount/dismount a bicycle wheel in a single motion. An outer shell contains a single cam operated by an external lever. One feature of the cam is a detent that, when the cam is rotated to the proper position and pulled back, mates with a shoulder to effectively lock the skewer shaft in place. Upon rotation of the lever, the internal cam is pulled to the locked position where the wheel will clear impediments on a bicycle frame or fork without any additional manipulation. 
         [0013]    For the present invention, a skewer shaft is connected to a spring loaded piston located inside a shell. A shaft connects to the piston and through the wall of the shell as well, connecting to an external lever. An internal cam is fitted about the shaft such that when the external lever is operated, the shaft turns the cam causing the shell to move laterally with respect to the piston. 
         [0014]    The internal cam has a unique detent on its outer surface. As the lever is actuated and then pulled away from the bicycle frame, the cam is pulled back and places the detent directly over a shoulder formed by a cavity inside the shell. The detent seats on this shoulder and, since the piston and shell are spring loaded with respect to each other, the skewer shaft becomes locked at its outward-most lateral position. At this point any impediment to removing the wheel, for example safety tabs or derailleur parts, has been cleared and the rider may simply drop the wheel. In this way a single motion of the lever allows a rider to remove a wheel from a bicycle frame. 
         [0015]    As well as the advantages discussed above, other advantages of the present invention are discussed below in conjunction with the drawings and figures attached. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1 : is a side sectional view of the present invention. 
           [0017]      FIG. 2 : is a top sectional view of the present invention. 
           [0018]      FIG. 3 : is a diagram showing operation of the present invention. 
           [0019]      FIG. 4 : shows operation of the apparatus of the present invention in the context of a conventional bicycle wheel. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0020]    As described briefly above, the apparatus of the present invention provides substantial improvements in the way a bicycle wheel is mounted/dismounted to/from a bicycle frame. The improvement is based upon a unique skewer release mechanism. 
         [0021]    Looking at  FIG. 1 , the apparatus  10  of the present invention is shown in a side sectional view. A shell  12  contains a piston  32  with a cam receiving cavity  30 , a detent shoulder  34 , a cam  20  with a detent  22 , a compression spring  14  and an end cap  16 . A contemporary skewer shaft  18  is an integral part of the piston  32  but is otherwise identical to and operates in the same manner as other contemporary skewers, thus the opposite end is not shown or discussed to aid in clarity. 
         [0022]    In a preferred embodiment, the shell is made from aluminum and has an outer diameter of approximately 0.75 inch and an inner diameter of approximately 0.5 inch. Those of skill in the art will recognize that the shell could be made form a different material and have dimensions different than those given without departing from the spirit of the invention, thus the scope of the invention is limited only be the claims. The piston, cam and skewer shaft of the present invention are made from steel but could be made from other materials without departing from the spirit of the invention. 
         [0023]    Looking at  FIG. 2 , a top section view  10  of the apparatus of the present invention is shown. In this view shell  12 , end cap  16  and skewer shaft  18  are the same items as in  FIG. 1 . Note that skewer shaft  18  is connected to the piston [ 32  of  FIG. 1 ]. A lever  15  is connected to shaft  17 . The shaft  17  has cam  20  as an integral part. The cam is configured such that one side is flat so that when rotated approximately 90 degrees from the vertical it can pass beneath a shoulder in a cavity of the piston. The combined shaft  17  and cam  20  pass through shell  12  and the piston  32  such that any motion of the lever  15  results in a lateral motion of the shell  12 . 
         [0024]    Operation of the present invention is shown in  FIG. 3 . Beginning with  3 A, the release lever [item  15  in  FIG. 2 ] of the apparatus is shown in position A, the closed, or in-use position. In this state, spring  14  pushes sliding piston  32  against the inner surface of the shell  12  and the action of cam  20  against the sliding piston  32  generates the clamping force required to ensure that the wheel is firmly attached to the bicycle frame. The clamping force is transmitted via skewer shaft  18  pulling cap  52  against the lugs of a bicycle frame. Neither the lugs nor the frame are shown for clarity, however, those of skill in the art will recognize that these components operate in the conventional manner. 
         [0025]    Moving to  3 B, the user has begun the dismounting process by moving the release lever to the B position. Doing so releases the clamping force of cam  20  against piston  32 . In  3 C the release lever is horizontal. At this time the release lever is at position C and cam  20  has rotated to the point where no more force is exerted against piston  32 , leaving the shell  12  free to move over the piston. Since the piston  32  is stationary, a gap G begins to form as the shell  12  moves. 
         [0026]    Looking now at  3 D, the user has applied a pulling force on the release lever at position C′ causing the spring  14  to compress. This pulling force moves cam  20  into the vacant cam receiving cavity [ 30  of  FIG. 1 ] creating gap G′ between the sliding shell  12  and the surface of the piston  32 . The user then moves the release lever to position D, as shown in  3 E, at which time the detent  22  in cam  20  mates with shoulder  34  on piston  32  effectively locking the cam  20  against the shoulder of the piston  32 . At this time the shell  12  has moved 0.26 inches with respect to the piston  32 , providing more than enough clearance to remove the wheel without interfering with the safety tabs. The combination of the pulling action and the locking cam are unique and a significant improvement over the prior art. 
         [0027]    While  FIG. 3  is an accurate description of the operation of the apparatus of the present invention, it is useful to show how the operation relates in the context of a conventional bicycle wheel.  FIG. 4A  shows the apparatus of the present invention in the normal, in-use state. A contemporary bicycle hub  54  is mounted between two wheel lugs  56 A and  56 B. Each of the wheel lugs  56 A and  56 B has a safety tab  57 A and  57 B respectively associated with it. A skewer shaft  18  has a cap  52  threaded on it at one end, and the apparatus of the present invention attached at the opposite end. 
         [0028]    As was described in association with  FIG. 3 , lever  15  is at position A when in use. In this position cam  20  has applied a captive pulling force such that spring  14  is decompressed and shell  12  and related parts described above press on lug  56 B while cap  52  exerts a force on lug  56 A. At this point the cam receiving cavity  30  is empty. However, even if lever  15  is accidentally moved towards position C, as shown in  FIG. 4B , the wheel will remain mounted due to the force of spring  14  against sliding piston  32 . This is a significant safety improvement over contemporary skewer release mechanisms. 
         [0029]    To dismount the wheel, lever  15  is moved first to position C as shown in  FIG. 4B . At this time sliding piston  32  is still pressed against shell  12  by spring  14  as detailed just above. The user then pulls lever  15  in such a way as to cause the flat side of cam  20  to move into cam receiving cavity  30 . At this point gap G′ has formed as the result of the compression of spring  14 . Two approximately equal gaps Y 1  and Y 2  are formed. These gaps measure approximately 0.13 of an inch and are sufficient to allow the wheel to clear safety tabs  57 A and  57 B shown in  FIG. 4A . The user then moves lever  15  to position D where the detent in cam  20 , described in detail above in conjunction with  FIGS. 1 and 3 , seats on the shoulder  34  of the cavity  30  [ 22  of  FIG. 3E ]. This locks the sliding piston  32  in place with respect to shell  12 , allowing the user to simply drop the wheel away from the bicycle frame. 
         [0030]    The mounting process is the reverse of the dismounting process. The user simply places the wheel in the lugs of the bicycle frame and operates the release lever until it is in position A. Once the user has moved the lever  15  toward the in-use position A, the cam detent  22  unseats from the shoulder of the piston and, since the shell  12  and piston  32  are spring loaded with respect to each other, the gap G′ closes and the skewer shaft  18  applies the requisite pulling orce to lock the wheel in place. 
         [0031]    One advantage of the present invention is that sufficient movement of the skewer ends is provided such that no additional manipulation of the skewer nut is required in order to mount or dismount the wheel. 
         [0032]    A second advantage of the present invention is a significant increase in rider safety. Unlike conventional skewer release methods, if the lever is inadvertently loosened, the apparatus of the present invention maintains sufficient force on the various skewer components to keep it in place. 
         [0033]    A third advantage of the present invention is that it employs a locking cam mechanism that, in combination with a pulling action by the user, fixes the skewer ends in place for ease of dismounting and remounting of a bicycle wheel. 
         [0034]    A fourth advantage of the present invention is that may be used on either the front or rear wheel of a bicycle. Moreover, due to the positive locking action of the cam and the horizontal travel distance, the invention may be used with all types of bicycles that use a standard skewer mechanism, including both road and mountain bicycles.