DESCRIPTION

FIELD OF THE INVENTION

[0001 ] This embodiment of the invention relates generally to skateboards and also rol ler skates, more particularly, to skateboards and rollers skates incorporating truck assemblies configured to maximize the trucks steermg responsiveness and directional control. The prior art trucks currently in use do not take full ad vantage of the rebound properties of the stabilizing bushing components. This embodiment of the invention engages the elastomeric bushings to a greate degree impro ving the trucks steering responsiveness.

BACKGROUND OF THE INVENTIO

[0002] Skateboards typically include a platform having a pair of truck assemblies mounted at the opposite ends of its underside. Each truck incorporates 2 primary components, a base plate secured to the platform and a hanger assembly having a pair of wheels. The hanger assembly includes an axle that mounts the two wheels at its opposite ends, and it further includes a hanger pivot that projects outward from the hanger for seating in a pivot cup in the base plate. A ring-shaped hanger flange also projects outward from the hanger for engagement with a kingpin that protrudes from the base plate. Top and bottom elastomeric bushings, disposed around the kingpin, sit on either side of the hanger flange and secure the hanger around the kingpin.

[0003] The truck assemblies described briefly above are configured to enable a rider to steer the skateboard simply by shifting his/her weight distribution side-to-side on the skateboard platform. The shift in weight causes the base plate, which is fixed to the skateboard platform, to tilt relative to the hanger and the hanger to pivot about the kingpin, which, by causing the wheels to pivot horizontally, enables the rider to steer left or right.

[0004] The tilt of the base plate causes only one side of each bushin g, top and bottom, to be compressed between the hanger flange and the supporting washers, the opposite sides of each bushin remain neutral, this is called a "single action" bushing. The rebound characteristics of the compressed portion of the bushings centre the truck to its original position once tire weight distribution returns, to normal, this gives the rider steering responsiveness and helps to stabilize the truck.

SUMMARY OF THE INVENTION

[0005] hi an embodiment of the present inventio a "double action" skateboard truck assembly is configured to maximize the skateboard's steering responsiveness. More particularly, the truck assembly includes a base plate secured to the platform and a hanger assembly having a pair of wheels. The hanger assembly includes an axle that mounts the two wheels at its opposite ends, and it further includes a hanger pivot that projects outward from the hanger for seating in a pivot cup in the base plate. A ring-shaped hanger flange which has a provision for a bushing assembly also projects outward from the hanger.

[0006] to an embodiment of the present invention, the bushing assembly comprises a rigid disk and top and bottom elastomeric bushings which are attached to either side of the rigid disk. The bushing assembly is installed into the hanger flange for engagement with a kingpin that protrudes from the base plate. The bushing assembly secures the hanger around the kingpin.

[0007] When the base plate tilts in relation to the hanger one side of each bushing becomes compressed while the opposite sides are elongated this is called a "double action" bushing, hence the rebound properties of both sides of each bushing assists in centring the truck to its original position creating a more responsive and stable skateboard.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a typical prior art skateboard truck assembly;

FIG. 2 is an enlarged, cross-sectional view of prior art taken along line 2-2 in FIG. 1 ;

FIG, 3 is an exploded view of a typical prior art skateboard truck assembly;

FIGS. 4 is an elevational view of a typical prior art skateboard truck assembly, wheels being shown in phantom, il lustrating tilting of the wheel ax les and related structure as typically occurs during a truck turning;

FIG. 5 is a view similar to FIG. 2 but illustrating a bushing assembly comprising a rigid disk, to which the "double action" top and bottom track bushings are attached in accordance with the teachings of an embodiment of the present invention; FIG. 6 is an exploded, perspective view illustrating an embodiment of the present invention of FIG. 5;

FIGS. 7 is a view similar to FIG. 4 but illustrating a bushing assembly comprising a rigid disk to which the "double action" top and bottom track bushings are attached in accordance with the teachings of an embodiment of the present invention;

FIG. 8 is detailed view, in cross-section of a bushing assembly useful in an embodiment of the present invention.

FIG. 9 is an exploded, perspective view illustrating an alternative embodiment of the present invention; and

FIG. 10 is detailed view, in cross-section of a bushing member useful in an alternative embodiment of the present invention.

DESCRIPTIO OF EMBODIMENTS

[0008] FIGS. ! , 2 and 3 illustrate a typical prior art skateboard truck assembly having "single action" bushing assembly. The assembly includes a base plate 5 for attachment to the underside of a skateboard. A king pin 6 projects from the base plate and has a threaded distal end 7.

[0009] A, hanger 8 defines a ring shaped hanger flange 9, the king pin 6 projecting through the hanger flange opening. Axles 17 project from the ends of hanger 8, upon which are mounted the skate wheels.

[0010] Resilient bushings 10, 11 encircle the king pin. The bushings are spaced from one another and disposed on opposed sides of the hanger flange 9. Located be!ow bushing 11 and in engagement therewith is a cup-shaped washer 12 encircling the king pin and disposed between the base plate 5 and bushing 11. A similarly shaped washer 13 is disposed above bushing 10. A king pin nut 14 is threaded onto the threaded end of king pin 7 and is in engagement with washer 13. Tightening or loosening of the king pin nut will respectively increase or decrease compressive forces applied to the bushings to modify the steering characteristics of the skateboard.

[0011] The hanger 8 includes a hanger pivot 15. Hanger pivot IS is positioned in a pivot cup 16 disposed in a recess of the base plate. The pivot cup 16 is relatively hard but permits some movement of the hanger pi vot relative to the assembly base during use of the skateboard. [0012] FIG. 4, illustrates a typical prior art skateboard track assembly having "single action" bushing assembly. The hanger 8 and related structure is shown to be tilted relative to the base plate 5. kingpin 6 and washers 12 and 13 as typically occurs during skateboard turning. Due to the tilt of the hanger 8 relative to the supporting washers 13 and 12 a compressive force is applied to one side of each bushing, top 1 A and bottom 11 A. A portion of each bushing remains neutral, top I OB and bottom 1 I B, due to there being no applied forces either compressive or tensional. The resulting resistance generated by only one side of each bushing lends the prior art design to be deemed a "single action" truck.

[0013] FIGS. 5-6, illustrate an embodiment of the present invention having several structural components of the type utilized in the prio art device shown in FIGS. 1-4. The "double action" truck assembly includes a base plate 40 for attachment to the underside of a skateboard platform and a king pin 41 projecting from the base plate and having a threaded distal end 42. A hanger 43 defines a ring shaped hanger flange 44 with pro vision for a bushing assembly. A bushing assembly comprising a rigid disk 45 and top 47 and bottom 48 elastorneric bushings is secured into the hanger flange by a threaded interface or other means. The king pin 41 projects through the bushing assembly.

[0014] Located below bushing 48 and in engagement therewith is a cup-shaped washer 49 encircling the king pin and disposed between the base plate 40 and bushing 48. A similarly shaped washer 50 is disposed above bushing 47. A king pin nut 51 is threaded onto the threaded end of king pin 41 and is m engagement with washer 50.

[0015] The hanger 43 includes a hanger pivot 52. Hanger pivot 52 is positioned in a pivot cup 53 disposed in a recess of the base plate. The pivot cup 53 is relatively hard but permits some movement of the hanger pivot relative to the assembly base during use of the skateboard. Axles 46 project from the ends of hanger 43, upon which are mounted the skate wheels.

[0 16] FIG. 7 illustrates an embodiment of the present invention. The hanger 43 and related structure is shown to be tilted relati ve to the base plate 40, kingpin 41 and washers 49 and 50 as typically occurs during a skateboard turning. Due to the tilt of the hanger 43 relative to the supporting washers 50 and 49 a compressive force is applied to one side of each bushing, top 47 A and bottom 48A. Moreover, with trucks of the invention, the compressing of one side of each, bushing member results in a tensional resistance arising in the opposite side of each bushing, top 47B and bottom 48B. The rebound properties of both sides of each bushing lends this embodiment of the present invention to be deemed a "double action" truck.

[0017] FIG, 8 illustrates an embodiment of a bushing assembl useful in the present invention comprised of a top bushing 6.1 and a bottom bushing 63 which are attached either chemically, mechanically or both to a rigid disk 62. The rigid disk 62 can be manufactured from almost any substantially rigid material. Metals such as aluminium, stainless steel and brass can be used, as can be substantially rigid plastic materials such as hard polyurethanes and fibregtass-remforced thermoplastic methanes. The material can be modified with a commercial coating to increase "bond ability" with the elastomeric bushings 61 and 63. This embodiment of the bushing assembly shows a threaded circumference for engagement with the hanger flange. In a typical embodiment, the elastomeric bushings 61 and 63 are cast from high rebound polyurethane with a hardness between about 70 Shore A and about 100 Shore A. A rider can select a bushing durometer or hardness, providing either a greater or lesser degree of responsiveness as is desired. The bushing assembly has a central bore 60 for receiving the kingpin, the central bore having a diameter slightly larger than of the king pin.

[0018]FIG. 9 illustrates an alternative embodiment of the present invention having several structural components of the type utilized in the prior art device shown in FIGS. 1-4. The "double action" track assembly incl udes a base plate 80 for attachment to the underside of a skateboard platform and a king pin 82 projecting from the base plate and having a threaded distal end 81. A hanger 78 defines a ring shaped hanger flange 79 with provision for a set of bushin members. A top bushing member comprising a rigid disk S3 and elastomeric bushing 70 and bottom bushing member comprising a rigid disk 84 and elastomeric bushing 71 are secured into the hanger flange by a threaded interface or other means. The king pin 82 projects through the bushing members.

[0019] Located below bushing 71 and in engagement therewith is a cup-shaped washer 72 encircling the king pin and disposed between the base plate 80 and bushing 71. A similarly shaped washer 73 is disposed above bushing 70. A king pin nut 74 is threaded onto the threaded end of king pin 81 and is in engagement with washer 73. [0020] The hanger 78 includes a hanger pivot 75. Hanger pivot 75 is. positioned in a pivot cup 76 disposed in a recess of the base plate. The pivot cup 76 is relatively hard but permits some movement of the hanger pivot relative to the assembly base during use of the skateboard. Axles 77 project from the ends of hanger 78, upon which are mounted the skate wheels.

[0021 ] FIG. 10 illustrates an alternative embodiment of a bushing member useful in the present invention comprised of an elastomeric bushing 91 and a rigid disk 92 which are attached either chemically, mechanically or both. The rigid disk 92 can be manufactured from almost any substantially rigid material. Metals such as aluminium, stainless steel and brass can be used, as can be substantially rigid plastic materials such as hard polyurethanes and fibreglass-reinforced thermoplastic urethanes. The material can be modified with a commercial coating to increase "bond ability" with the elastomeric bushing 91. This embodiment of the bushing member shows a threaded circumference for engagement with the hanger flange. In a typical embodiment the eiastomeric bushing 91 is cast from high rebound polyurethane with a hardness between about 70 Shore A and about 100 Shore A. A rider can select a bushing durometer or hardness, providing either a greater or lesser degree of responsiveness as is desired. The bushing member has a central bore 90 for receiving the kingpin, the central bore having a diameter slightly larger than of the king pin .

[0022] Having thus described some embodiments of the present invention, it should be apparent that numerous structural modifications and. adaptations may be resorted to without depart ing from the scope and fair meaning of the instant invention as set forth herein above and as described herein below by the claims.