Abstract:
A truck assembly for a skateboard or the like that is configured to eliminate the undesired ride characteristic of wheel bite without sacrificing the turning responsiveness thereof and without deviating from the general shape and form of a typical skateboard truck. In the preferred embodiment of the invention each truck assembly includes an axle assembly with a ring-shaped member, disposed about a kingpin, that includes two threaded bores longitudinally oriented in the general plane of the ring-shaped member substantially parallel to the axis of the axle and on generally opposite sides of the kingpin, in each of which is positioned a bolt whose distance from the kingpin is determined by actuation of the bolt such that when the axle assembly pivots through an angle about the axis of the kingpin and causes one or more of the bolts to contact the kingpin, the contacting bolt or bolts resists any further pivoting of the axle assembly beyond that angle. In a further feature of the invention the kingpin is modified to define a flat edge along generally opposite sides thereof, each flat edge being adjacent to each bolt positioned within its respective threaded bore.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates generally to vehicles that employ an axle or axle assembly that pivots relative to the vehicle to permit turning thereof and, more specifically, to a truck assembly that prevents the axle or axle assembly from pivoting beyond a specified angle relative to the vehicle. Such a truck assembly is of use for skateboards or other recreational vehicles to secure the wheels thereto.  
         [0002]     A skateboard typically comprises an elongated platform with a pair of truck assemblies secured at opposite ends to the underside of the platform. Each truck assembly typically comprises a base that is non-moveably secured to the platform and a hanger assembly, which includes an axle, that is moveably secured to the base by means of a kingpin bolt such that the hanger assembly can pivot along the axis of the kingpin bolt relative to the base and the skateboard platform. The hanger and base of a typical skateboard truck assembly is formed of a durable and light-weight material such as cast aluminum and the axle and kingpin bolt are constructed of an extremely durable material such as hardened steel.  
         [0003]     A pair of wheels can be secured at opposite ends of the axle. When a skateboarder shifts his weight to one side of the skateboard platform, the hanger assembly pivots relative to the platform and makes the distance between the wheels, whose plane of rotation remains unchanged relative to the axis of the axle, on that side of the platform shorter than the distance between the wheels on the other side of the platform, thereby causing the skateboard to turn.  
         [0004]     The ability to adjust the steering responsiveness of a skateboard truck assembly is very important since different skateboarders may prefer a different steering responsiveness and even the same skateboarder may prefer a different steering responsiveness at different times. A desired steering responsiveness can be achieved by tightening or loosening a kingpin nut secured to the threaded end of the kingpin bolt of the truck assembly, which determines the ease at which the hanger assembly pivots along the axis of the kingpin bolt relative to the base and platform. Tightening the kingpin nut increases the resistance of the axle to pivot and makes the skateboard less willing to turn. Likewise, loosening the kingpin nut decreases the resistance of the axle to pivot and makes the skateboard more willing to turn.  
         [0005]     There have been several truck assemblies previously proposed that can be used to secure wheels to a vehicle such as a skateboard and permit turning thereof.  
         [0006]     U.S. Pat. No. 6,793,224 (Stratton) discloses a skateboard truck that pivots about two axes and provides a combination of adjustable lateral stability and enhanced turning abilities.  
         [0007]     U.S. Pat. No. 6,547,262 (Yamada and Hiranuma) discloses a skateboard truck assembly in which the pivot arm of the truck hanger rotates freely in a bearing assembly supporting the pivot arm in the socket hub.  
         [0008]     U.S. Pat. No. 6,523,837 (Kirkland) discloses an adjustable truck assembly for skateboards with a retainer that provides a large turning radius for the axle, a highly predictable turning performance, and tool-less adjustment of the turning performance.  
         [0009]     U.S. Pat. No. 6,474,666 (Andersen and Andersen) discloses a shock-absorbing skate truck assembly that includes a resilient shock absorber at the kingpin located between the assembly base of the assembly and the axle support member for absorbing shocks encountered during use and another shock absorber that is located in a recess of the assembly base and is engaged by an axle support member arm.  
         [0010]     U.S. Pat. No. 6,443,471 (Mullen) discloses a truck assembly configured to eliminate undesired ride characteristics such as hanger-jiggle and wheel bite without sacrificing the skateboard&#39;s steering responsiveness, which generally comprises an axle assembly with a ring-shaped hanger that is confined on a kingpin using a pair of bushings, at least one of which includes an annular flange that projects into an annular gap that is defined between the hanger and the kingpin.  
         [0011]     U.S. Pat. No. 6,428,023 (Reyes and Horn) and U.S. Pat. No. 6,315,312 (Reyes and Horn) disclose a truck assembly including a housing adapted to be mounted to a skateboard or the like, which generally comprises an axle bracket that is mounted for rotation transverse to the longitudinal axis and that includes a projecting upper end portion and a bottom end portion adapted to receive a transversely extending axle and wheel assembly, a resilient member located at least partially in the housing that is adapted to resist transverse rotation of the axle bracket and provide a restoring force, and a wedge member that has an aperture configured for receiving the projecting upper end portion of the axle bracket to establish a direct coupling therebetween.  
         [0012]     U.S. Pat. No. 6,367,819 (Andersen and Andersen) discloses a shock-absorbing skate truck assembly including a resilient shock absorber at the kingpin located between the assembly base of the assembly and the axle support member for absorbing shocks encountered during use.  
         [0013]     U.S. Pat. No. 6,318,739 (Fehn, Jr.) discloses a suspension assembly for a skateboard which generally comprises a base plate with a truck plate pivotally attached at one end with a shock absorber located between the base plate and the truck plate and further with a projection on the base plate that protects the shock absorber and aids the rider in performing tricks.  
         [0014]     U.S. Pat. No. 6,315,304 (Kirkland et. al.) discloses an adjustable truck assembly for a skateboard, which generally comprises an axle housing, a base, a kingpin connecting the axle housing and base, a turning mechanism between the axle housing and base around the kingpin consisting of opposed cam surfaces that are angled along the axis of the kingpin and an elastomeric bushing so that rotating the axle housing about the kingpin pushes the cam surfaces apart against the compression pressure of the elastomeric bushing, and an adjustment mechanism for adjusting the pressure against the bushing.  
         [0015]     U.S. Pat. No. 6,224,076 (Kent) and U.S. Pat. No. D439,945 (Kent) disclose a pneumatic compression strut skateboard truck that utilizes a pneumatic compression strut suspension system, which is of the same type and kind used in automobiles and other mechanical devices employing shock absorbing technology.  
         [0016]     U.S. Pat. No. 6,182,987 (Bryant) discloses a truck assembly with replaceable axles and ball joint pivots that incorporates precision steering and rocking components for consistency and accuracy during maneuvers, a method for removing or replacing worn or broken axles, and a precision ball pivot pin that acts as the associate pivotal and rocking mechanism for the truck assembly.  
         [0017]     U.S. Pat. No. 5,971,411 (Jones and Jones) discloses a skateboard truck, which generally comprises an extruded skateboard truck base that has an angled aperture for a cushion on which a hanger rests and a pivot bolt that holds the hanger to the base and that allows weight placed on either side of the skateboard to put pressure on the cushion to facilitate a turn.  
         [0018]     U.S. Pat. No. 5,263,725 (Gesmer and Haug) discloses a skateboard truck that incorporates exceptionally rapid and consistently accurate axle rebound to the straight-ahead position, consistent and predictable steering response, an improved balance between stability and maneuverability, fine steering control, and a wide range of steering radii, which generally comprises a yoke, a pivot pin, and coil springs.  
         [0019]     U.S. Pat. No. 4,398,734 (Barnard) discloses a truck design for a skate-type device involving turning and tilting axes of rotation, which generally comprises a T-shaped rod, the top part being housed in a base plate and the leg passing through a slot in the base plate, a resilient pad, washers, an axle yoke, and an adjustable lock nut.  
         [0020]     U.S. Pat. No. 4,251,087 (Hansen) discloses a truck apparatus for skate and skateboard devices, which generally comprises an elongated kingpin, a means for affixing the upper end of the kingpin to the bottom of a load carrying platform, a wheel axle carriage assembly pivotally affixed to the lower end of the kingpin and adapted to rotate about the axis of the kingpin, a resilient drag sleeve and turn restoring element compressively disposed between the first and second friction surfaces, and a lock nut for selectively urging the carriage assembly towards the mid-portioned member so as to compress the drag sleeve between the first and second friction surfaces such that the carriage assembly may be resistively and partially resiliently rotated about the axis of the kingpin.  
         [0021]     U.S. Pat. No. 4,185,847 (Johnson) and U.S. Pat. No. 4,176,850 (Johnson) disclose skateboard trucks that carry a plurality of wheels mounted in independent suspension, which generally comprise longitudinally extending arms that carry the wheel axles forwardly or rearwardly relative to a mounting that secures the arms in rotatable fashion to the trucks and that are resiliently biased by means of separate springs or torsion bars.  
         [0022]     U.S. Pat. No. 4,184,693 (Whitmarsh) discloses a skateboard truck, which generally comprises a base plate for securing to the underside of a skateboard platform and a spring member, such as a plate spring, that is joined to the base plate by one end and carries a wheel axle near an opposite end.  
         [0023]     U.S. Pat. No. 4,166,629 (List) discloses a skateboard truck, which generally comprises a base that has a first portion with a first hole therein and a second portion with a second hole therethrough, a hanger that has an axle for mounting wheels thereon, a ring and a pin, the pin being received in the first hole, and a coupling assembly for coupling the hanger to the base.  
         [0024]     U.S. Pat. No. 4,152,001 (Christianson) discloses a truck for a skateboard or the like, which generally comprises an S-shaped leaf spring that attaches to the skateboard and, through a pivot pin, carries a transverse axle-supporting member at the opposite end and further generally comprises a pair of upwardly and inwardly inclined compression springs that are engaged by a pin carried by the leaf spring to resist pivotal movement of the leaf spring relative to the axle-supporting member.  
         [0025]     U.S. Pat. No. 4,103,917 (Widolf) discloses a skateboard truck, which generally includes a wheel housing resiliently mounted on a skateboard truck base by means of a fastener which extends through the housing and is threaded onto a stud fixed to the base to compress a tubular cushion between the housing and the base, in which the fastener has a square cross-section that mates with a square bore in the cushion so that rotation of the fastener with respect to the cushion is prevented except when the retainer is manually and forceably rotated to adjust the compression on the cushion.  
         [0026]     Although these prior art truck assemblies are capable of securing wheels to a vehicle such as a skateboard and permit turning thereof, they suffer from one or more disadvantageous properties. Skateboarders have become accustomed to the general shape and form of a typical skateboard truck assembly, so much that many of the maneuvers a skateboarder performs relies on this general property. Therefore, the above previously proposed truck assemblies that deviate significantly from the general shape and form of a typical skateboard truck assembly are highly undesired.  
         [0027]     The remaining above previously proposed truck assemblies that do not deviate significantly from the general shape and form of a typical skateboard truck assembly have a design flaw that can result in an undesired ride characteristic called wheel bite. When a skateboarder uses his skateboard to perform maneuvers, such as riding off an obstacle, his balance may not be completely centered upon the skateboard platform. Such an uneven distribution of weight can cause the hanger assembly to pivot through a great angle relative to the platform and cause the wheels to contact the platform, called wheel bite. Wheel bite can cause the wheels to stop rotating and the skateboard to stop moving, and often causes the skateboarder to fall. The only way to prevent wheel bite is to tighten the kingpin nut to sufficiently retard the pivoting action of the hanger assembly, but this inhibits the steering responsiveness of the skateboard and is therefore highly undesired. Although U.S. Pat. No. 6,443,471 (Mullen) claims to solve wheel bite by providing a bushing with an annular flange, it still relies on the tightness or looseness of a kingpin nut to function and therefore affects the steering responsiveness of the skateboard. Furthermore, because the device of U.S. Pat. No. 6,443,471 (Mullen) is comprised of a soft material, it cannot completely prevent wheel bite.  
         [0028]     Accordingly, what is desired, and has not heretofore been developed, is a truck assembly that has the same general shape and form of a typical skateboard truck assembly but can prevent wheel bite without affecting the steering responsiveness of the skateboard. Furthermore, because a skateboard can be configured with differently sized wheels and because skateboard platforms can have different degrees of concavity such that the angle through which the hanger assembly must pivot to cause wheel bite can be different for different skateboards, what is desired, and has not heretofore been developed, is a skateboard truck assembly in which the maximum angle through which the hanger assembly can pivot is easily adjusted by the user.  
       BRIEF SUMMARY OF THE INVENTION  
       [0029]     It is an object of the present invention to provide a skateboard truck assembly that prevents wheel bite.  
         [0030]     It is an object of the present invention to provide a skateboard truck assembly wherein the maximum angle through which the hanger assembly can pivot relative to the skateboard platform is easily adjusted by the user.  
         [0031]     It is an object of the present invention to provide a skateboard truck assembly wherein the maximum angle through which the hanger assembly can pivot relative to the skateboard platform is independent to its pivot sensitivity and therefore independent to the steering responsiveness of the skateboard.  
         [0032]     It is an object of the present invention to provide a skateboard truck assembly that is inexpensive to manufacture.  
         [0033]     It is an object of the present invention to provide a skateboard truck assembly that is easy to use.  
         [0034]     It is an object of the present invention to provide a skateboard truck assembly that does not deviate significantly from the general shape and form of typical skateboard truck assembly.  
         [0035]     It is an object of the present invention to provide a skateboard truck assembly whose turning responsiveness does not deviate significantly from that of a typical skateboard truck assembly.  
         [0036]     The above comments apply equally to any vehicle that employs a hanger assembly that pivots relative to the vehicle to permit turning thereof. Furthermore, the above comments apply equally to any wheel-securing, blade-securing, or other device-securing assembly that employs a pivoting axle or axle assembly for which it is desired to specify a maximum angle through which the axle or axle assembly can pivot relative to the vehicle while not affecting the pivot sensitivity of the axle or axle assembly.  
         [0037]     The above objects, features, and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings, which illustrate by way of example, the principles of the invention. The same reference numerals are used to identify the same or similar parts in each of the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0038]      FIG. 1  is a perspective view of a typical prior art skateboard truck assembly.  
         [0039]      FIG. 2  is a bottom view of the prior art skateboard truck assembly shown in  FIG. 1 .  
         [0040]      FIG. 3  is a side view of the prior art skateboard truck assembly shown in  FIG. 1 .  
         [0041]      FIG. 4  is a cross-sectional view of the prior art skateboard truck assembly shown in  FIG. 2  taken along line A-A.  
         [0042]      FIG. 5   a  is a perspective view of the two set screws used in the first embodiment of the present invention,  FIG. 5   b  is a perspective view of the modified kingpin that may be used in the first embodiment of the present invention, and  FIG. 5   c  is a perspective view of the bushings that may be used in the first embodiment of the present invention.  
         [0043]      FIG. 6   a  and  FIG. 6   b  are cross-sectional views of the hanger of a skateboard truck assembly, like that shown in  FIG. 3  taken along line B-B, that is modified to accept and accepting the device of  FIG. 5   a  and  FIG. 5   b.    
         [0044]      FIG. 7   a  through  FIG. 7   d  are cross-sectional views of the device shown in  FIG. 5   a  when engaged to a hanger and with a kingpin bolt therebetween, in which the maximum angle through which the device can pivot along the axis of the kingpin bolt is shown.  
         [0045]      FIG. 8  is a view of the different parts of a skateboard truck assembly, like that shown in  FIG. 1 , that is modified to accept the devices shown in  FIG. 5   a ,  FIG. 5   b , and  FIG. 5   c.    
         [0046]      FIG. 9  is a perspective view of the assembled skateboard truck assembly shown in  FIG. 8 .  
         [0047]      FIG. 10  is a perspective view of a second embodiment of the present invention.  
         [0048]      FIG. 11   a  and  FIG. 11   b  are cross-sectional views of the hanger of a skateboard truck assembly, like that shown  FIG. 3  taken along line C-C, that is modified to accept and accepting the device of  FIG. 10 .  
         [0049]      FIG. 12  is a view of the different parts of a skateboard truck assembly, like that shown in  FIG. 1 , that is modified to accept the device shown in  FIG. 10 .  
         [0050]      FIG. 13  is a perspective view of the assembled skateboard truck assembly shown in  FIG. 12  or  FIG. 18 .  
         [0051]      FIG. 14  is a perspective view of a third embodiment of the present invention.  
         [0052]      FIG. 15  is a cross-sectional view of a skateboard truck assembly, like that shown in  FIG. 2  taken along line A-A, that is modified to accept and accepting the device of  FIG. 14 .  
         [0053]      FIG. 16   a  and  FIG. 16   b  are cross-sectional views of the hanger of a skateboard truck assembly, like that shown in  FIG. 3  taken along line B-B, that is modified to accept and accepting the device of  FIG. 14 .  
         [0054]      FIG. 17   a  through  FIG. 17   d  are cross-sectional views of the device shown in  FIG. 14  when engaged to a hanger and with a kingpin bolt therethrough, in which the maximum angle through which the device can pivot along the axis of the kingpin is shown.  
         [0055]      FIG. 18  is a view of the different parts of a skateboard truck assembly, like that shown in  FIG. 1 , that is modified to accept the device shown in  FIG. 14 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0056]      FIG. 1  shows a perspective view of a typical prior art skateboard truck assembly  1 , which generally comprises a base  2  and a hanger  3 . The hanger  3  includes an axle  4 , on which wheels can be secured, a ring-shaped member  29  through which a kingpin bolt  5  is positioned, and a pivot stem  30  that extends into a pivot cup  12  that rests in a recess defined in the base  2  on which the hanger  3  can pivot. The base  2  is non-moveably secured to a skateboard platform by means of a plurality of mounting holes  11  through which bolts can be inserted. The hanger  3  is moveably secured to the base  2  by sandwiching part of the ring-shaped member  29  between an upper bushing  7 , above which resides an upper bushing upper washer  9 , and a lower bushing  8 , below which resides a lower bushing lower washer  10 , through which is routed the kingpin bolt  5  whose non-threaded end is secured to the base  2  and on whose threaded end a kingpin nut  6  is secured.  FIG. 2  and  FIG. 3  show a bottom elevation view and a side elevation view, respectively, of the typical prior art skateboard truck assembly  1  shown in  FIG. 1 .  
         [0057]      FIG. 4  shows a cross-sectional view of the prior art skateboard truck assembly  1  shown in  FIG. 2  taken along the line A-A. The upper bushing  7 , lower bushing  8 , upper bushing upper washer  9 , lower bushing lower washer  10 , and ring-shaped member  29  each has a bore defined therethrough through which the kingpin bolt  5  is routed. The flange  13  is the part of the ring-shaped member  29  that is sandwiched between the upper bushing  7  and lower bushing  8  by means of the kingpin nut  6  secured to the threaded end of the kingpin bolt  5 , securing the hanger  3  and axle  4  to the base  2 . Because there is an annular space between the kingpin bolt  5  and the flange  13  and because the upper bushing  7  and lower bushing  8  are formed of a pliable material such as polyurethane, the described configuration permits the hanger  3  and axle  4  to pivot along the axis of the kingpin bolt  5  relative to the base  2  on the pivot stem  30  that extends into a pivot cup  12  that rests in the recess  31  defined in the base  2 .  
         [0058]     In the above-described prior art skateboard truck assembly  1  the ease at which the hanger  3  can pivot along the axis of the kingpin bolt  5  relative to the base  2  is determined by how tightly the flange  13  is sandwiched between the upper bushing  7  and lower bushing  8 . To increase the resistance of the hanger  3  to pivot along the axis of the kingpin bolt  5  relative to the base  2 , which decreases the steering responsiveness of the skateboard, the kingpin nut  6  is tightened such that increased pressure is applied to the flange  13  by the upper bushing  7  and lower bushing  8 . Likewise, to decrease the resistance of the hanger  3  to pivot along the axis of the kingpin bolt  5  relative to the base  2 , which increases the steering responsiveness of the skateboard, the kingpin nut  6  is loosened such that decreased pressure is applied to the flange  13  by the upper bushing  7  and lower bushing  8 . Although it is highly desired for a skateboard to have a sensitive steering responsiveness, the required decreased resistance of the hanger  3  to pivot can result in the hanger  3  pivoting through a great angle along the axis of the kingpin bolt  5  relative to the base  2  such that the wheels, which are secured to the ends of the axle  4 , contact the underside of the skateboard platform, called wheel bite.  
         [0059]      FIG. 5   a  shows an elevation view of a pair of set screws  14  that are part of the first embodiment of the present invention, whose purpose is to stop the hanger  3  and axle  4 , like those shown in  FIG. 1 , from pivoting beyond a specified angle along the axis of the kingpin bolt  5  relative to the base  2  by contacting the kingpin bolt  5 .  FIG. 5   b  shows an elevation view of a modified kingpin bolt  33  that can also be part of the first embodiment of the present invention, which has a flattened edge  34  defined along boths sides thereon, permitting the set screws  14  to make secure contact thereto.  FIG. 6   a  and  FIG. 6   b , which are cross-sectional views of the hanger  3  of a skateboard truck assembly  1  like that shown in  FIG. 3  taken along the line B-B when the hanger  3  and axle  4  are in the non-pivoting position relative to the base  2 , show the set screws  14  engaged to the hanger  3  through a pair of threaded bores  15  defined in the ring-shaped member  29 , which are longitudinally oriented in the general plane of the ring-shaped member  29  substantially parallel to the axis of the axle  4  on generally opposite sides of the modified kingpin bolt  33 , such that the distance between the end of each set screw  14  and the modified kingpin bolt  33  is determined by the amount each set screw  14  is actuated into or out of its respective threaded bore  15 .  
         [0060]      FIG. 6   a  shows the position of each set screw  14  when it is fully actuated into its respective threaded bore  15 , in which the end of each set screw  14  is nearly contacting or contacting the modified kingpin bolt  33 . Likewise,  FIG. 6   b  shows the position of each set screw  14  when it is fully actuated out from its respective threaded bore  15  but not yet removed from the hanger  3 , in which there is ample space between each set screw  14  and the modified kingpin bolt  33 .  
         [0061]     An extended flange  16  is defined in the ring-shaped member  29  of the hanger  3  that reduces the gap between the ring-shaped member  29  and the modified kingpin bolt  33  on either side of the modified kingpin bolt  33  in the direction perpendicular to the axis of the axle  4 . When the hanger  3  pivots through a specified angle along the axis of the modified kingpin bolt  33  relative to the base  2  and causes one or both set screws  14  to contact the modified kingpin bolt  33 , which resists any further pivoting of the hanger  3  beyond that angle, the extended flange  16  prevents the hanger  3  from moving relative to the modified kingpin bolt  33  in the plane of the ring-shaped member  29  in the direction generally perpendicular to the axis of the axle  4 .  
         [0062]      FIG. 7   a  through  FIG. 7   d  show, by means of cross-sectional views of each set screw  14  and the modified kingpin bolt  33  positioned therebetween, the pivot action of the set screws  14 , which are in secured to the hanger  3  as shown in  FIG. 6   a  and  FIG. 6   b , along the axis of the modified kingpin bolt  33 , which is secured to the base  2  as shown in  FIG. 4 . The gap between the end of each set screw  14  and the modified kingpin bolt  33  determines the maximum angle through which the hanger  3  and axle  4  can pivot along the axis of the modified kingpin bolt  33  relative to the base  2 . In  FIG. 7   a  the end of each set screw  14  is actuated to be nearly in contact or in contact with the modified kingpin bolt  33 , completely preventing the hanger  3  and axle  4  from pivoting along the axis of the modified kingpin bolt  33  relative to the base  2 . In  FIG. 7   d  the end of each set screw  14  is actuated a distance far from the modified kingpin bolt  33  such that the hanger  3  and axle  4  can pivot through a great angle along the axis of the modified kingpin bolt  33  relative to the base  2  before causing one or both set screws  14  to contact the modified kingpin bolt  33 .  FIG. 7   b  and  FIG. 7   c  show intermediate distances of the end of each set screw  14  from the modified kingpin bolt  33 , which permit intermediate maximum angles through which the hanger  3  and axle  4  can pivot along the axis of the modified kingpin bolt  33  relative to the base  2 .  
         [0063]     Because the actuation of each set screw  14  into its threaded bore  15  or the actuation of each set screw  14  out from its threaded bore  15  is in a direction generally perpendicular to the axis of the modified kingpin bolt  33  (or kingpin bolt  5  if a modified kingpin bolt  33  is not used), the maximum angle through which the hanger  3  and axle  4  can pivot along the modified kingpin bolt  33  relative to the base  2  is independent to the tightness or looseness of the kingpin nut  6  secured to the threaded end of the modified kingpin bolt  33 , and is therefore independent to the steering responsiveness of the skateboard.  
         [0064]     If the thickness of the flange  13  or extended flange  16  is not increased to be be larger than the diameter of the set screws  14 , a channel  28 , which is shown in  FIG. 5   c , can be defined on the lower side of the upper bushing  7  and the upper side of the lower bushing  8  adjacent to each set screw  14  to provide substantially unimpeded actuation of each set screw  14  towards or away from the modified kingpin bolt  33 .  
         [0065]      FIG. 8  shows how each set screw  14  is engaged to a skateboard truck assembly  1 , which consists of a hanger  3  that includes an axle  4  and a base  2  that has several mounting holes  11  for securement to a skateboard platform. The modified kingpin bolt  33  is inserted through the top of the base  2 , through the upper bushing upper washer  9 , upper bushing  7  which rests on the extended flange  16  and on the bottom of which is defined a channel  28 , lower bushing  8  on which rests the extended flange  16  and on the top of which is defined a channel  28 , and lower bushing lower washer  10 . The kingpin nut  6  is secured to the threaded end of the modified kingpin bolt  33  to secure the hanger  3  to the base  2 . The pivot stem  30  extends into the pivot cup  12  that rests in a recess  31  defined in the base  2 . Each set screw  14  is inserted into its respective threaded bore  15 , which is defined in or near the ring-shaped member  29 , and actuated such that the end of each set screw  14  is positioned at a desired distance from the flattened edge  34  of the modified kingpin bolt  33 .  FIG. 9  shows the assembled skateboard truck assembly  1  shown in  FIG. 8 , which has the same general shape, form, and steering characteristics of a typical skateboard truck assembly but can prevent wheel bite.  
         [0066]     It is apparent that various modifications can be made to the first embodiment of the present invention described above without departing from the spirit and scope of the invention. For example, although each set screw  14  shown in  FIG. 5   a  is drawn as a headless bolt to reduce any protrusion of the set screw  14  from the exterior of the hanger  3  that may result, any type of bolt or actuation element can be used. Furthermore, employing a modified kingpin bolt  33  with a flattened edge  34  defined along either side can be beneficial to ensure secure contact of each set screw  14  thereto, but it is not required. Also, although the longitudinal orientation of each threaded bore  15  is shown parallel to each other in  FIG. 6   a  and  FIG. 6   b , it may be advantageous to define an angle therebetween. Even elements other than a pair of bolts can be used to contact the kingpin bolt  5  or modified kingpin bolt  33  when the hanger  3  and axle  4  pivot through a specified angle along the axis of the kingpin bolt  5  or modified kingpin bolt  33  relative to the base  2  and, furthermore, the means of actuating the element or elements can be either directly or indirectly accomplished via actuation of another element or elements. Accordingly, drawings for second and third embodiments of the present invention are included, which are briefly described below.  
         [0067]      FIG. 10  shows a second embodiment of the present invention, which generally comprises a c-shaped element  17 , a wedge element  18 , and a screw  19  that is engaged to the wedge element  18 .  FIG. 11   a  and  FIG. 11   b , which are cross-sectional views of the hanger  3  of a skateboard truck assembly  1  like that shown in  FIG. 3  taken along the line C-C, show the device of  FIG. 10  engaged to the hanger  3  in a first bore  20  that is defined partially in the part of the ring-shaped member  29  nearest the axle  4  for accepting the c-shaped element  17  and partially in the hanger  3  for accepting the wedge element  18 , and a second bore  21  that is defined in the hanger  3  for accepting the screw  19 . The c-shaped element  17  rests on a partial flange  32  that is defined in the ring-shaped member  29  and the wedge element  18  is engaged by the screw  19 .  
         [0068]      FIG. 11   a  shows the generally perpendicular position of the c-shaped element  17 , the wedge element  18 , and the screw  19  relative to the axis of the kingpin bolt  5  when the screw  19 , whose head rests between a first flange  22  and a second flange  23  that are both defined in the second bore  21  of the hanger  3 , is actuated such that the wedge element  18 , to which it is engaged, is pushed towards the kingpin bolt  5 , causing the c-shaped element  17  to close in towards the kingpin bolt  5 . Likewise,  FIG. 11   b  shows the position of the c-shaped element  17 , the wedge element  18 , and the screw  19  when the screw  19  is actuated such that the wedge element  18  is pulled away from the kingpin bolt  5 , causing the c-shaped element  17  to open up away from the kingpin bolt  5 . Similar to the first embodiment of the present invention, the gap between the c-shaped element  17  and the kingpin bolt  5 , determined by the position of the wedge element  18  relative to the c-shaped element  17 , determines the maximum angle through which the hanger  3  and axle  4  can pivot along the axis of the kingpin bolt  5  relative to the base  2  on the pivot stem  30 .  
         [0069]      FIG. 12  shows how the c-shaped element  17 , wedge element  18 , and screw  19  are engaged to a skateboard truck assembly  1  that consists of a hanger  3  that includes an axle  4  and a base  2  that has several mounting holes  11  for securement to a skateboard platform. The c-shaped element  17  is inserted into the part of the first bore  20  defined in the ring-shaped member  29  and rests on the partial flange  32 , the wedge element  18  is inserted into the part of the first bore  20  defined in the hanger  3 , and the screw  19  is inserted into the second bore  21  defined in the hanger  3  and engaged to the wedge element  18 . The kingpin bolt  5  is inserted through the top of the base  2 , through the upper bushing upper washer  9 , upper bushing  7  which rests on the c-shaped element  17 , lower bushing  8  on which rests the c-shaped element  17 , and lower bushing lower washer  10 . The kingpin nut  6  is secured to the threaded end of the kingpin bolt  5  to secure the hanger  3  to the base  2 . The pivot stem  30  extends into the pivot cup  12  that rests in a recess  31  defined in the base  2 .  FIG. 13  shows the assembled skateboard truck assembly  1  shown in  FIG. 12  which has the same general shape, form, and steering characteristics of a typical skateboard truck assembly but can prevent wheel bite. The head of the screw  19  is positioned against the second flange  23 .  
         [0070]      FIG. 14  shows a third embodiment of the present invention, which generally comprises an elongated element  26 , which has a trapezoidal-shaped bore  27  defined therein, and a screw  19  engaged thereto.  FIG. 15 , which is a cross-sectional view of a skateboard truck assembly  1  like that shown in  FIG. 2  taken along the line A-A, shows the device of  FIG. 14  engaged to the hanger  3 , which includes the axle  4 , in a first bore  20  that is defined partially in the ring-shaped member  29  and partially in the hanger  3  for accepting the elongated element  26  and a second bore  21  that is defined in the hanger  3  for accepting the screw  19 , both of which are generally perpendicular to the axis of the kingpin bolt  5 .  
         [0071]     Actuating the screw  19 , whose head rests between a first flange  22  and a second flange  23 , causes the elongated element  26  to move relative to the kingpin bolt  5 , which is routed through the trapezoidal-shaped bore  27  defined in the elongated element  26 , such that the kingpin bolt  5  can be positioned at different locations within the trapezoidal-shaped bore  27 . Because a void will exist between the upper bushing  7  and lower bushing  8  on the exterior of the elongated element  26  when the elongated element  26  is moved nearer to the head of the screw  19 , an upper bushing lower washer  24  is placed below the upper bushing  7  and a lower bushing upper washer  25  is placed above the lower bushing  8  in addition to the upper bushing upper washer  9  that resides above the upper bushing  7  and the lower bushing lower washer  10  that resides below the lower bushing  8 . The kingpin nut  6  is secured to the threaded end of the kingpin bolt  5  to secure the hanger  3  to the base  2 . The pivot stem  30  extends into the pivot cup  12  that rests in a recess  31  defined in the base  2 .  
         [0072]      FIG. 16   a  and  FIG. 16   b , which are cross-sectional views of the hanger  3  of a skateboard truck assembly  1  like that shown in  FIG. 3  taken along the line B-B, show the device of  FIG. 14  engaged to the hanger  3  through a first bore  20  defined therein for accepting the elongated element  26  and a second bore  21  for accepting the screw  19 .  FIG. 16   a  shows the position of the elongated element  26  within both the ring-shaped member  29  and hanger  3  and the position of the screw  19 , whose head rests between a first flange  22  and a second flange  23 , when the screw  19  is actuated such that the narrow end of the trapezoidal-shaped bore  27  that is defined in the elongated element  26  is pulled towards the kingpin bolt  5 . Likewise,  FIG. 16   b  shows the position of the elongated element  26  and the screw  19  when the screw  19  is actuated such that the narrow end of the trapezoidal-shaped bore  27  is pushed away from the kingpin bolt  5 . Similar to the first embodiment of the present invention, the gap between the elongated element  26  and the kingpin bolt  5 , defined by the position of the kingpin bolt  5  within the trapezoidal-shaped bore  27 , determines the maximum angle through which the hanger  3  and axle  4  can pivot along the axis of the kingpin bolt  5  relative to the base  2  on the pivot stem  30 .  FIG. 17   a  through  FIG. 17   d  show, by means of cross-sectional views of the elongated element  26  and kingpin bolt  5  positioned therethrough, the pivot action of the elongated element  26 , which is secured to the hanger  3  as shown in  FIG. 16   a  and  FIG. 16   b , along the axis of the kingpin bolt  5 , which is secured to the base  2  as shown in  FIG. 15 .  
         [0073]      FIG. 18  shows how the elongated element  26 , in which the trapezoidal-shaped bore  27  is defined, and the screw  19  are engaged to a skateboard truck assembly  1  that consists of a hanger  3  that includes an axle  4  and a base  2  that has several mounting holes  11  for securement to a skateboard platform. The elongated element  26  is inserted into the first bore  20  defined in both the ring-shaped member  29  and hanger  3  and the screw  19  is inserted into the second bore  21  defined in the hanger  3  and engaged to the elongated element  26 . The kingpin bolt  5  is inserted through the top of the base  2 , through the upper bushing upper washer  9 , upper bushing  7 , upper bushing lower washer  24  which rests on the elongated element  26 , lower bushing upper washer  25  on which rests the elongated element  26 , lower bushing  8 , and lower bushing lower washer  10 . The kingpin nut  6  is secured to the threaded end of the kingpin bolt  5  to secure the hanger  3  to the base  2 . The pivot stem  30  extends into the pivot cup  12  that rests in a recess  31  defined in the base  2 .  FIG. 13  shows the assembled skateboard truck assembly  1  shown in  FIG. 18  which has the same general shape, form, and steering characteristics of a typical skateboard truck assembly but can prevent wheel bite. The head of the screw  19  is positioned against the second flange  23 .  
         [0074]     Although several specific embodiments of the present invention have been illustrated and described, many variations or modifications would be apparent that do not depart from the spirit and scope of the invention, which are defined by the appended claims.