Abstract:
A hanger for a skateboard truck that generally comprises a ring-shaped member, a pivot stem, and an elongated barrel that houses an axle. Such elongated barrel defines a plurality of corrugations on the bottom thereof, the longitudinal axis of each corrugation aligned generally perpendicular to the longitudinal axis of such elongated barrel. Such corrugations are strategically distributed along such elongated barrel to ensure adequate engagement of some number of corrugations with such obstacle during a grind, helping to prevent such hanger from slipping off from such obstacle in a direction generally perpendicular to the general direction of intended grinding motion along such obstacle. Such hanger can be adapted to cooperate with a variety of existing skateboard truck baseplates.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application No. 60/880,839, filed Jan. 17, 2007 by Michael Knapton. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to an improved hanger of a skateboard truck of a skateboard, heretofore referred to as a truck, wherein such improved hanger helps stabilize such skateboard during certain tricks and maneuvers, specifically trucks stalls and grinds. 
         [0003]    A skateboard generally comprises an elongated deck, two trucks, and four wheels. Two wheels are secured to opposite ends of an axle portion of each truck. Each truck is secured to opposite ends of the bottom surface of the deck. A skateboard is generally ridden with a skateboarder positioned on the top surface of the deck and the wheels contacting the ground or an obstacle, wherein the general direction of motion is parallel to the longitudinal axis of the deck. 
         [0004]    A skateboarder may perform tricks and maneuvers while riding his or her skateboard. A truck stall is when the hanger of at least one truck is positioned in direct contact with an edge or apex of an obstacle, stalling the general motion of the skateboarder and skateboard. A grind is when the hanger of at least one truck is positioned in direct contact with an edge or apex of an obstacle but the skateboarder and skateboard continue their general direction of motion, literally grinding the hanger along the obstacle. Heretofore the term grind refers to either a grind or a truck stall. 
         [0005]    The hanger of a truck generally comprises a ring-shaped member, a pivot stem, and an elongated barrel that houses an axle. During truck grinds, it is the bottom surface of the elongated barrel that contacts the edge or apex of the obstacle. This elongated barrel is generally cylindrical, flat along its longitudinal axis, and almost always smooth or polished to minimize friction during a grind. The elongated barrel of popular trucks manufactured during the 1970s was sometimes rectangular, generally much shorter than those of today, and sometimes included a logo or ornamentation impressed therein. However, as skateboard tricks and maneuvers progressed and grinding became popular, only smooth and flat elongated barrels remained practical. 
         [0006]    Numerous trucks are described in the prior art, each describing various modifications or improvements thereof. A few prior art patents are listed below. 
         [0007]    U.S. Pat. No. 7,150,460 (Williams), U.S. Pat. No. 6,547,262 (Yamada et. al.), and U.S. Pat. No. 6,182,987 (Bryant) teach trucks with improved turning responsiveness. 
         [0008]    U.S. Pat. No. 7,093,842 (Chmelar) teaches a truck with wheel bite prevention. 
         [0009]    U.S. Pat. No. 6,443,471 (Mullen) teaches a truck with a replaceable slide plate. 
         [0010]    U.S. Pat. No. 6,474,666 (Andersen et. al.), U.S. Pat. No. 6,367,819 (Andersen et. al.), and U.S. Pat. No. 4,152,001 (Christianson) teach shock-absorbing trucks. 
         [0011]    U.S. Pat. No. 7,243,925 (Lukoszek), U.S. Pat. No. 6,523,837 (Kirkland), and U.S. Pat. No. 6,315,304 (Kirkland et. al.) teach configurable trucks. 
         [0012]    U.S. Pat. No. 5,971,411 (Jones et. al.), U.S. Pat. No. 4,398,734 (Barnard), and U.S. Pat. No. 4,184,693 (Whitmarsh) teach easily manufactured trucks. 
         [0013]    U.S. Pat. No. D257,051 (Chambers) teaches a truck with a design impressed on the bottom surface of the elongated barrel. 
         [0014]    U.S. Pat. No. 6,761,369 (Anderson) teaches a truck with a low-friction grinding ability. 
         [0015]    The smooth and longitudinally flat elongated barrel of the above prior art trucks create a limitation that manifests during a grind attempt. When a skateboarder engages his or her skateboard onto an obstacle to attempt a grind, the elongated barrel contacting such obstacle may slip off from such obstacle in a direction generally perpendicular to the general direction of intended grinding motion along such obstacle, resulting in a failed grind attempt. The improved hanger of the present invention, which can be adapted to cooperate with a variety of existing skateboard truck baseplates, defines a plurality of corrugations on the bottom of the elongated barrel, each generally perpendicular to the longitudinal axis thereof. Such corrugations help to prevent such elongated barrel from slipping off from an obstacle when in contact therewith, thereby increasing the stability of the skateboard during a grind. 
         [0016]    U.S. Pat. No. D477,648 (Smith), U.S. Pat. No. 6,056,302 (Smith), and U.S. Pat. No. D421,082 (Lopez) also teach trucks that result in increased stability during a grind; however, the mechanism taught or shown thereby is a large and generally smooth channel formed at the medial portion of the bottom surface of the elongated barrel. Such a channel operates to partially encompass an edge or apex of an obstacle during a grind, as is typically formed to cooperate best with the standard two-inch diameter round pipe found on most skateboard ramps and obstacles. In contrast, each individual corrugation of the present invention is significantly smaller than such channel. Furthermore, such corrugations are strategically distributed along the bottom of the elongated barrel to ensure adequate engagement of some number of corrugations with an obstacle during a grind, regardless of the general shape of the edge or apex of such obstacle. 
         [0017]    U.S. Pat. No. D256,263 (Brawner), U.S. Pat. No. D252,693 (Brawner), and U.S. Pat. No. 4,109,925 (Williams, et. al.) teach trucks that include a pair of ornamental ribs at each distal end of the elongated barrel. Such distal location of such ornamental pairs of ribs makes engagement with an edge or apex of most obstacles therewith during a grind attempt impossible. For example, such ornamental distal pairs of ribs could not engage a standard two-inch diameter round pipe that is found on most skateboard ramps and rails. In contrast, the corrugations of the present invention, which are strategically distributed along the bottom of the elongated barrel, ensure adequate engagement of some number of corrugations with such obstacle during a grind. Accordingly, the quantity of individual corrugations defined on the elongated barrel of the present invention is greater than the quantity of such individual ornamental distal ribs defined on such elongated barrels of such prior art trucks. 
         [0018]    Accordingly, what is desired, and has not heretofore been developed, is a skateboard truck hanger that defines a plurality of corrugations strategically distributed along the bottom of the elongated barrel of such hanger, capable of engaging an edge or apex of an arbitrary obstacle during a grind, thereby helping to prevent such elongated barrel from slipping off from such obstacle in a direction generally perpendicular to the general direction of intended grinding motion along such obstacle. In a further feature of the present invention, the corrugations of the hanger protract upwards on a front portion of the elongated barrel at a specified angle towards the pivot stem of the hanger. 
       BRIEF SUMMARY OF THE INVENTION 
       [0019]    It is an object of the present invention to provide a hanger of a skateboard truck that defines on the bottom of its elongated barrel a plurality of corrugations. 
         [0020]    It is an object of the present invention that the longitudinal axes of such corrugations is aligned generally perpendicular to the longitudinal axis of such elongated barrel. 
         [0021]    It is an object of the present invention that such corrugations are strategically distributed along such elongated barrel to ensure adequate engagement of some number of such corrugations with an arbitrary obstacle during a grind. 
         [0022]    It is an object of the present invention that such corrugations are formed by any means, for example cast in place or machined. 
         [0023]    It is an object of the present invention that such corrugations may be formed by adding material to an elongated barrel (additive process), by subtracting material from an elongated barrel (subtractive process), or by both adding and subtracting material from an elongated barrel (combined additive and subtractive process). 
         [0024]    It is a further object of the present invention to provide a hanger of a skateboard truck that defines on the bottom of its elongated barrel a plurality of corrugations that protract upwards on a front portion of such elongated barrel. 
         [0025]    It is a further object of the present invention that such protracted corrugations defined on a front portion of such elongated barrel protract upwards at an arbitrary angle towards the pivot stem of the hanger. 
         [0026]    It is an object of the present invention that any such corrugated hanger can be adapted to cooperate with a variety of existing skateboard truck baseplates to form a functional skateboard truck. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is a perspective view of a typical skateboard. 
           [0028]      FIG. 2   a ,  FIG. 2   b , and  FIG. 2   c  are front, bottom, and back views of a typical skateboard truck, respectively. 
           [0029]      FIG. 3   a  is a perspective view of a skateboarder slipping off from an obstacle during a grind attempt, and  FIG. 3   b  is a perspective view of only the skateboard of  FIG. 3   a.    
           [0030]      FIG. 4   a  is a perspective view of a skateboarder not slipping off from an obstacle during a grind, and  FIG. 4   b  is a perspective view of only the skateboard of  FIG. 4   a.    
           [0031]      FIG. 5   a ,  FIG. 5   b ,  FIG. 5   c , and  FIG. 5   d  are front, bottom, back, and side views of a first embodiment of the hanger of the present invention, respectively. 
           [0032]      FIG. 6   a ,  FIG. 6   b ,  FIG. 6   c , and  FIG. 6   d  are front, bottom, back, and side views of a second embodiment of the hanger of the present invention, respectively. 
           [0033]      FIG. 7   a ,  FIG. 7   b ,  FIG. 7   c , and  FIG. 7   d  are front, bottom, back, and side views of a third embodiment of the hanger of the present invention, respectively. 
           [0034]      FIG. 8   a ,  FIG. 8   b ,  FIG. 8   c , and  FIG. 8   d  are front, bottom, back, and side views of a fourth embodiment of the hanger of the present invention, respectively. 
           [0035]      FIG. 9   a ,  FIG. 9   b ,  FIG. 9   c , and  FIG. 9   d  are front, bottom, back, and side views of a fifth embodiment of the hanger of the present invention, respectively. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]      FIG. 1  shows a typical skateboard  10  contacting a surface  5 , including a deck  20 , four wheels  30 , and two trucks  100 .  FIG. 2   a ,  FIG. 2   b , and  FIG. 2   c  show more detailed views of a truck  100 , generally comprising a baseplate  110  and a hanger  120 , joined together by means of a bolt called a kingpin  170 . The kingpin  170  extends downwardly from the baseplate  110 , through a pair of bushings  160 , and through the ring-shaped member  140  of the hanger  120 . The bushings  160  sandwich the ring-shaped member  140  and provide an elestomeric response when the hanger  120  pivots during a turn. The kingpin  170  typically has a threaded portion on the lowermost distal end for communication with a bolt that secures the bushings  160  and ring-shaped member  140  in place; however, the kingpin  170  may be inverted with its threaded portion within the baseplate  110  and its head on the lowermost distal end. 
         [0037]    The hanger  120  includes an axle  130  to secure wheels  30  thereto. The axle  130  is contained within an elongated barrel  180 , which is the lowermost portion of the hanger  120 . Although the elongated barrel  180  is shown longitudinally flat, it may be shaped as any prior art hanger, for example it may include a channel at its median; the corrugations of the present invention may be used with any such hanger, not simply a longitudinally flat hanger. A pivot stem  150  extends upwards from the median of the elongated barrel  180  to communicate with a frontal portion of the baseplate  110 . The baseplate  110  attaches to the deck  20 . 
         [0038]      FIG. 3   a  shows a skateboarder  1  slipping off from an obstacle  40  while attempting a grind.  FIG. 3   b  shows a more detailed view of only the skateboard  10  of  FIG. 3   a . The elongated barrel  180  of the truck  100  is in direct contact with the obstacle  40  during a grind. Because the elongated barrel  180  is smooth and flat along its longitudinal axis, it is very easy for the elongated barrel  180  to slip off from the obstacle  40 , causing the skateboarder  1  to fall. Furthermore, because the wheels  30  extend downward below the elongated barrel  180 , if the wheels  30  contact the obstacle  40  during the grind attempt, the elongated barrel  180  is tilted at some angle with respect to a stable horizontal position, increasing the tendency of the elongated barrel  180  to slip off from the obstacle  40 . 
         [0039]      FIG. 4   a  shows a skateboarder  1  successfully grinding an obstacle  40 .  FIG. 4   b  shows a more detailed view of only the skateboard  10  of  FIG. 4   a . The corrugations  124  defined on the bottom of the elongated barrel  180  communicate with the obstacle  40 , preventing the elongated barrel  180  from slipping off from the obstacle  40 . 
         [0040]      FIG. 5   a ,  FIG. 5   b ,  FIG. 5   c , and  FIG. 5   d  show front, bottom, back, and side views of a first embodiment of the hanger  120  of the present invention. A pivot stem  150  extends upwardly and forwardly from the median of the hanger  120  and a ring-shaped member  140  extends backwardly from the median of the hanger  120 . The lowermost portion of the hanger  120  defines an elongated barrel  180 , within which is housed an axle  130 . Two regions of corrugations  124  are defined on the bottom of the elongated barrel  180 , near the distal ends thereof. The longitudinal axis of each corrugation  124  is perpendicular to the longitudinal axis of the elongated barrel  180 . 
         [0041]    Although the regions of corrugations  124  are shown extending to the very distal ends of the elongated barrel  180 , such need not be the case; there may be a region lacking corrugations on each distal end thereof. Furthermore, although not illustrated, alternate truck hanger anatomies, such as those of typical longboard, slalom, or racing trucks, in which both the pivot stem  150  and ring-shaped member  140  extend forwardly from the median of the elongated barrel  180 , are also within the scope of the present invention. 
         [0042]    The minimal length of each region of corrugations  124 , defined as the length of such corrugations  124  along the longitudinal axis of the elongated barrel  180 , is sufficient to ensure at least some portion of corrugations  124  will communicate with an obstacle  40  of arbitrary shape during a grind, for example the edge of a curb or a two-inch diameter metal pipe. For grinding a two-inch diameter pipe, such minimal length may be defined to be approximately one inch. 
         [0043]    The corrugations  124  may be formed on the elongated barrel  180  by an additive process wherein material is added to the elongated barrel  180  to form the corrugations  124 , by a subtractive process wherein material is removed from the elongated barrel  180  to form the corrugations  124 , or by a combined additive and subtractive process wherein material is both added and subtracted from the elongated barrel  180  to form the corrugations  124 . The elevation of a corrugation  124  is heretofore used to refer to the portion thereof that extends outwardly from the axle  130  of the elongated barrel  180 . The depression of a corrugation  124  is heretofore used to refer to the portion thereof that extends inwardly towards the axle  130  of elongated barrel  180 . In the additive process, the elevations extend beyond the periphery of the elongated barrel  180  and the depressions neither extend beyond nor within the periphery of the elongated barrel  180 . In the subtractive process, the depressions extend within the periphery of the elongated barrel  180  and the elevations neither extend beyond nor within the periphery of the elongated barrel  180 . Finally, in the additive and subtractive process, the elevations extend beyond the periphery of the elongated barrel  180  and the depressions extend within the periphery of the elongated barrel  180 . Any particular formation of corrugations  124  of any embodiment of the present invention is shown for illustrative purposes only and is not intended to restrict any particular embodiment to a particular type of formation of corrugations  124 . For example,  FIG. 5   a ,  FIG. 5   b ,  FIG. 5   c , and  FIG. 5   d  show corrugations  124  formed by a combined additive and subtractive process, in contrast to  FIG. 7   a ,  FIG. 7   b ,  FIG. 7   c , and  FIG. 7   d  which show essentially the same hanger  120  but with corrugations  124  formed by a subtractive process. Furthermore, on a given hanger  120 , individual corrugations  124  may be formed by different processes, for example corrugations  124  at the distal ends formed by an additive process while corrugations  124  at the median formed by a subtractive process. 
         [0044]    The elevation and depression profile of any individual corrugation  124 , as seen in the front views ( FIG. 5   a ,  FIG. 6   a ,  FIG. 7   a ,  FIG. 8   a , and  FIG. 9   a ) and back views ( FIG. 5   c ,  FIG. 6   c ,  FIG. 7   c ,  FIG. 8   c , and  FIG. 9   c ), may define any arbitrary profile, for example sinusoidal, square, triangular, or any combination thereof. Any particular corrugation  124  profile of any embodiment of the present invention is shown for illustrative purposes only and is not intended to restrict any particular embodiment to a particular type of corrugation  124  profile. For example,  FIG. 5   a  and  FIG. 5   c  show a corrugation  124  profile that appears sinusoidal (convex elevations and concave depressions), in contrast to  FIG. 7   a  and  FIG. 7   c  which show a corrugation  124  profile that appears to have convex elevations and flat depressions. 
         [0045]      FIG. 6   a ,  FIG. 6   b ,  FIG. 6   c , and  FIG. 6   d  show front, bottom, back, and side views of a second embodiment of the hanger  120  of the present invention. Here only a single region of corrugation  124  is defined, encompassing the entire length of the bottom of the elongated barrel  180 . Although the region of corrugation  124  is shown extending to the very distal ends of the elongated barrel  180 , such need not be the case; there may be a region lacking corrugations on each distal end thereof. 
         [0046]    Although not illustrated, more than one or two regions of corrugations  124  may be defined on the bottom of the elongated barrel  180 , for example three regions or four regions. 
         [0047]      FIG. 8   a ,  FIG. 8   b ,  FIG. 8   c , and  FIG. 8   d  show front, bottom, back, and side views of a fourth embodiment of the hanger  120  of the present invention. The corrugations  124  are defined on the bottom of the elongated barrel  180  and protract upwards on a front portion thereof at a specified angle towards the pivot stem  150 . Such forwardly protracted corrugations  124  aid in stabilizing the elongated barrel  180  during special special grind maneuvers wherein the deck  20  is tilted to cause only one elongated barrel  180  to directly contact the obstacle  40  (nose-grind, k-grind, 5-0 grind, etc.). During such special grinds, the longitudinal axis of the skateboard  10  is often times not aligned in the general direction of grinding motion, but is skewed to one side. The protraction of the corrugations  124  on the front portion of the elongated barrel  180  may be angled to correspond to such possible skew in the longitudinal axis of the skateboard  10  relative to the obstacle  40  during such a grind. Such angle of protraction of corrugation  124  is defined by the angle between a reference line drawn longitudinally along the bottom of the elongated barrel  180  and a reference line drawn longitudinally along the direction of protraction of the corrugation  124 . For example, a corrugation  124  that protracts vertically upwards defines a 90 degree angle with respect to the reference line drawn longitudinally along the bottom of the elongated barrel  180 . 
         [0048]    In the preferred embodiment of such upwardly protracted corrugations  124 , those located at the very distal ends of the elongated barrel  180  protract at a large angle and those near the median of the elongated barrel  180  protract at a smaller angle, as shown in  FIG. 8   a . Although not illustrated, the protractions of the corrugations  124  could define no angle, all the same angle, or arbitrary angles with respect to a line extending from the median of the elongated barrel  180  upwards through the median of the distal end of the pivot stem  150 . Any particular angle of protraction of corrugations  124  of any embodiment of the present invention is shown for illustrative purposes only and is not intended to restrict any particular embodiment to a particular angle of protraction of corrugations  124 . Furthermore, although not illustrated, not every corrugation  124  must be protracted upwardly and forwardly. For example, it may be beneficial that only a few corrugations  124 , or every other corrugation  124  include an upward and forward protraction. The correspondence of each corrugation  124  protracting upwardly and forwardly of any embodiment of the present invention is shown for illustrative purposes only and is not intended to restrict any particular embodiment to a particular correspondence of corrugations  124  that protract upwardly and forwardly. 
         [0049]      FIG. 9   a ,  FIG. 9   b ,  FIG. 9   c , and  FIG. 9   d  show front, bottom, back, and side views of a fourth embodiment of the hanger  120  of the present invention. Here only a single region of corrugation  124  and associated upward protractions is defined, encompassing the entire length of the bottom and forward portion of the elongated barrel  180 . Although the region of corrugation  124  is shown extending to the very distal ends of the elongated barrel  180 , such need not be the case; there may be a region lacking corrugations on each distal end thereof.