Skateboard truck with adjustable pivot point

The present invention relates to a novel skateboard truck. More particularly, the present invention pertains to skateboard truck with two independently adjustable pivot points that achieve a unique variable turning motion without affecting the skateboard's stability. Additionally, the skateboard truck includes an offset axle that swings towards the direction of the turn, thus shifting the wheels away from the side of the skateboard, eliminating wheel bite, and increasing stability.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an improved skateboard and skateboard truck. More particularly, the present invention pertains to skateboard truck with two independent pivot points, one fixed pivot point and one adjustable pivot point, which provide a variable turning capability without affecting the skateboard's stability.

2. Description of the Related Art

Conventional skateboards include an elongated board (i.e., deck) with two steering mechanisms (i.e., trucks) that are attached to the underside of the deck. A steering mechanism or truck usually consists of a base plate, bushings, a hangar or axle, and wheels. The base plates are attached to the underside of the board and have a king pin bolt and a pivot cup. The hangar has an extended tip which mates with the pivot cup of the base plate and creates the pivot point. The hangar also has a circular opening which is mounted on the king pin along with a top and bottom bushing. The bushings and hangar circular opening are held onto the king pin bolt by a lock nut which is screwed onto the open end of king pin bolt. The strength of the bushings and the level the lock nut is tightened determine the range the hangar can move or flex. The hangar also has an axle running through the long part of the hangar. The wheels are attached to the axles and held on to the axles by lock nuts. Standard skateboards have two trucks mounted or attached on the underside and at the front and back of the deck. The axis of each truck or axle is typically attached perpendicular to the longitudinal axis of the deck.

In order to steer the skateboard in a certain direction, the rider shifts their weight laterally across the longitudinal axis of the board causing the hangar to flex within the bushings and pivot cup mechanism to change the orientation of the truck axle with respect to the longitudinal axis of skateboard deck. The truck also serves as a suspension system that provides stability while the rider turns the skateboard. However, by stabilizing the board by tightening the king pin lock nut or by using harder bushings, the skateboard sacrifices its turning ability.

Skateboards and skateboard trucks have been made the same way for many years. However, what is needed is a way to create flexible turning on skateboards while maintaining stability.

SUMMARY OF THE INVENTION

This summary is provided to introduce concepts in a simplified form that are further described in the detailed description of the invention. This summary is not intended to identify key or essential inventive concepts of the claimed subject.

The present invention overcomes the limitations of known skateboard trucks by providing a skateboard truck with two independently operating pivot points that achieve a variable turning motion without affecting the skateboard's stability. Specifically, the present invention provides a truck with a variable turning radius which may be adjusted or modified by changing the horizontal and vertical distance between the first pivot point of the axle assembly and the adjustable secondary pivot point. By including an adjustable secondary pivot point to the truck, the skateboard is able to make tighter turns with less tilt from the rider. This is accomplished by adjusting the amount of turning angle relative to the degree of the board. Stated alternatively, if the skateboard was held at a constant angle of tilt, one could alter the turning radius of the skateboard by moving the adjustable secondary pivot point. By adjusting the second pivot point, the geometry of the truck has changed thereby changing the turning ratio or angle of turn of the skateboard even though the skateboard angle of tilt was held constant.

Adjusting the turning ratio is completely independent from the adjustment for board stability. Board stability in the present invention is achieved by rubber pads which are located on either side of the first pivot point, as well as a thin adjustable urethane pad positioned between the base plate and the bottom surface of the first pivot hub. By tightening the screws and driving the pad further into the decreasing space under the first pivot hub, stability is increased. The dual pivot point adjustment options of the present invention give users or skateboarders the ability to completely customize the ride of the skateboard to his or her preference.

The present invention also includes a unique offset axle. The offset of the axle from the pivot point swings or moves the axle towards the direction of the turn, thus shifting the wheels away from the side of the skateboard and eliminating or reducing wheel bite. The offset axle also provides additional stability when steering the skateboard by shifting the center of gravity towards the direction of the turn. This center of gravity shift is achieved by moving the entire axle toward the turn. As the rider shifts his weight laterally across the board, the rider's center of gravity also moves in the direction of the turn, thus keeping the center of gravity of the truck consistently under the rider giving him much more stability during a turn.

These and other objects, features, and/or advantages may accrue from various aspects of embodiments of the present invention, as described in more detail below.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

With reference to the figures where like elements have been given like numerical designations to facilitate the reader's understanding of the present invention, the preferred embodiments of the present invention are set forth below. The enclosed figures and drawings are merely illustrative of one or more of the preferred embodiments and, as such, represent one or more ways of configuring the present invention. Although specific components, materials, configurations and uses are illustrated, it should be understood that a number of variations to the components and to the configuration of those components described herein and in the accompanying figures can be made without changing the scope and function of the invention set forth herein. For instance, although the figures and description provided herein show certain configurations for the skateboard truck assembly of the present invention, a skateboard utilizing such truck assembly and wheels mounted to the truck assembly, those who are skilled in the art will readily understand that this is merely for purposes of simplifying the present disclosure and that the present invention is not so limited.

The preferred embodiment of the present invention is illustrated inFIGS. 1-7. As depicted inFIGS. 1-6, the truck100is comprised of a base plate101, a hanger103, a first pivot assembly, and a second pivot assembly. Attached to the hanger103are one or more axles109. The axels109or axel may be offset. One or more wheels139are connected to the axels109and are secured with a lock nut110. On the pivot end of the hangar, opposite from the axels109, is a first pivot opening112. Attached to the pivot end of the hangar103is a steering shaft111. The steering shaft111includes an attachment flange113which is mechanically fastened to the hanger103in a way that allows the steering shaft111to move along one axis relative to the hangar103. In the exemplary embodiment pictured, the attachment flange113is mechanically attached to the hanger103using threaded screws.

The hanger103is connected to the first pivot assembly through the opening112. The first pivot assembly includes the base plate101, the first pivot hub115, the first pivot shaft118, the stability pads141, the wedge pad143, and the bearing assembly. The bearing assembly is comprised of several parts including washers132,133, tapered roller bearings130,131, roller bearing cups128,129and a lock nut135. During assembly, the first pivot shaft118is inserted into an opening in the elevated sidewall124, then into a first bearing125, into an axial opening in the first pivot hub115, then into a second bearing125and terminating at a second elevated wall124. This places the first pivot hub into the cavity126. The first pivot hub115has a hub shaft127which is inserted through the washer132, roller bearing130, roller bearing cup128, the hanger opening112, roller bearing cup129, roller bearing131, washer133and finally through a lock nut135. The first pivot assembly secures the hanger103to the base plate101which is secured to the skateboard. The first bearing assembly allows the pivot hub115and shaft127(axis A inFIG. 1) to rotate relative to the first pivot point created by the first pivot assembly. The degree of rotation of the shaft (a inFIG. 1) is plus or minus 50° degrees relative to the non-flexed position.

The base plate101has one or more screw slots121to receive screws that secure the truck100to the skateboard deck. The base plate101includes a housing123that includes a plurality of elevated sidewalls124forming a cavity126for retaining the first pivot hub115, the stability pads141(seeFIG. 3), and the wedge pad143(FIG. 4). One or more of the elevated sidewalls124include circular openings for receiving the first pivot shaft118, and any screws145. The shaft127and first pivot hub115may be formed as one piece or fastened together by threaded mating party, welding, or similar means.

As described above, the first pivot shaft118is inserted into the circular openings in the walls124and into the first pivot hub115to secure the first pivot hub115to the base plate101. In an exemplary embodiment, the base plate101is configured to hold the first pivot hub115at an angle relative to the skateboard deck. In the exemplary embodiment, the angle would be at, close to, or approximately twelve degrees. However, the angle could be lower or higher than twelve degrees.

The truck100also includes a second pivot point through a second pivot assembly. The second pivot assembly includes a pivot pin137, a steering shaft111, and an eyeball bearing138. The base plate101contains a secondary pivot point adjustment slot119. This secondary pivot point adjustment slot119allows for the attachment of the secondary pivot pin137to the base plate101. This secondary pivot pin137can be adjusted horizontally along the adjustment slot119to modify the distance between the secondary pivot assembly and the first pivot assembly. The base plate101also contains a recess so that nut securing the secondary pivot pin137can sit flush with the base plate101. The secondary pivot pin137includes an eyelet117that can be raised or lowered along the pivot pin137shaft to further modify the variable turning radius of the steering shaft111. The steering shaft111is threaded through the eyeball bearing138and into the secondary pivot point eyelet117of the pivot pin137. The steering shaft111has an attachment flange113which is attached to the hanger103in a hinged configuration.

As shown inFIGS. 3-4, the preferred embodiment of the present invention also includes side stabilizing pads141and an adjustable stabilizing wedge pad143. In the preferred embodiment of the present invention, the side stabilizing pads141are made out of rubber and the adjustable wedge pad143is made out of urethane. Alternative embodiments may utilize other materials such as hard urethane (100% urethane), soft or foam like urethane, or other suitable material. The design may also incorporate springs or other mechanical tension configurations.

As shown inFIG. 3, two side rubber stabilizing pads141(one on either side of the shaft127) are positioned to push against the top lip116of the first pivot hub115. As shown inFIG. 4, a wedge pad143resides or is placed under the pivot hub115. The wedge pad143is ideally a urethane stabilizing pad located between the base plate101and the bottom of the first pivot hub115. One or more screws145are threaded through the base plate wall to push or pull the wedge pad143within the cavity126. The wedge pad143has a wedge shape which when pushed further into the cavity126reduces the space the pivot hub115has to move. Further, the pivot hub115has to directly contend with the resistance of the wedge pad143. By tightening or lessening the screw145, the wedge pad143is pushed into the decreasing space under the first pivot hub115to tighten the pad and further increase the truck's stability. In other words, when the screw145is tightened, bias pressure is being added onto the pad143resulting in less space for the first pivot hub115to flex.

FIGS. 5 and 6illustrate the adjustable secondary pivot assembly. As previously described, the secondary pivot assembly includes a pivot pin137, a steering shaft111, and an eyeball bearing138. The pivot pin137is mechanically fastened to the base plate101by one or more threaded fasteners or nuts. The pivot pin137may be moved along the slot119to adjust the pivot point of the second pivot assembly. The closer the pivot pin137is (along the slot119) to the first pivot assembly the truck100and board achieves a tighter deck turning radius allowing the skateboard rider to quickly turn the direction of the deck. As the pivot pin137is moved away from the first pivot assembly along the horizontal secondary pivot point adjustment slot119, the variable turning radius would provide a slower and wider turn.

The pivot pin137has a threaded eyelet117which can rotate along the threaded shaft connected to the base plate101to increase or decrease the height of the eyelet117relative to the base plate101. The height adjustment also helps to increase or decrease the rotation of the hanger103with tighter turning ratios coming when the eyelet117is at its near its maximum height. The steering shaft111is inserted into an eyeball socket or bearing138and into the eyelet opening117. The steering shaft111rotates about the pivot point created by the pivot pin137along the B axis. The rotation (β) of the steering pin111relative to the pivot pin137is plus or minus 40° degrees from neutral for a total of an 80° degree rotational movement. This rotation (β) is important for movement of the hanger103and axels109during turns.

The ability of the first pivot assembly to rotate plus or minus 50° degrees and the second pivot assembly to rotate plus or minus 40° degrees enables the hanger103and axels109to move significantly relative to the longitudinal axis of the board. For comparison, a standard skateboard truck under flex from a rider might cause the truck axel axis (generally perpendicular to the longitudinal axis of the board) to rotate plus or minus 20° degrees from the normal non-flexed axel axis. By comparison, the dual pivot assembly of the present invention allows the axel axis to rotate plus or minus 50° degrees from the non-flexed axel axis position. The increased axel rotation enables greater turning options.

However, another important aspect of the present invention is that during these extended rotational turns, the truck100design shifts the axel midpoint toward the direction of the turn or weight of the user. This axel midpoint shift increases the stability of the board during turns. As seen inFIGS. 7A-7F, the axel midpoint99shifts relative to the starting position or un-flexed position. The skateboards inFIGS. 7A-7Bdepict a truck100of the present invention on the front of the deck only. However, the truck100of the present invention could be used as the front and back truck.FIGS. 7A, 7C, and 7Eillustrated the underside of the skateboard whileFIGS. 7B, 7D, and 7Fshow the front the skateboard.

FIGS. 7A and 7Bshow the skateboard and truck in a non-flexed position. The axel midpoint99is positioned directly along the longitudinal axis of the board.FIGS. 7C and 7Dshow the skateboard and truck in a partially flexed position. The flex or weight causes the first pivot assembly to rotate α degrees (FIG. 7D) out from the vertical axis while the second pivot assembly causes the hanger103to rotate β degrees (FIG. 7C) out of the longitudinal axis. As seen inFIG. 7D, the axel midpoint99has shifted in the direction of the turn.

FIGS. 7E and 7Fshow the skateboard and truck in a heavily flexed position. The flex or weight causes the first pivot assembly to rotate α degrees (FIG. 7F) out from the vertical axis while the second pivot assembly causes the hanger103to rotate β degrees (FIG. 7E) out of the longitudinal axis. As seen inFIG. 7F, the axel midpoint99has shifted significantly in the direction of the turn.

For comparison, a standard skateboard truck might see movement of the axel midpoint during a turn move plus or minus ¼ of an inch relative to the longitudinal axis. In contrast, the dual pivot assembly design of the present invention enables the axel midpoint during a turn to move plus or minus 2 inches relative to the longitudinal axis. This significantly greater axel midpoint movement helps to keep the center of the truck under the center of gravity of the rider making the skateboard more stable. The axel midpoint for a single axel design would be the midpoint of the single axel. The axel midpoint for a hanger design which uses a left and right axel would be the midpoint as if the two axels were connected as one or the midpoint of the axis through the two axels. Although the design depicted in the images shows a hanger103with two axels109, the system could use a single axel design without deviating from the scope of the invention.

The present invention also includes an offset axle or axels109that may extend beyond the width of the skateboard deck. This offset axle109allows for the wheels139to move in the direction the rider is leaning. For example, if the rider shifts his weight to the right intending for the skateboard to make a right turn, the right front wheel moves behind the left front wheel (axel rotation) and the right back wheel moves in front of the left back wheel. At the same time, the entire axle assembly moves to the right moving the midpoint99toward the weight of the rider. By swinging the axle and wheels towards the direction of the turn, the wheels are shifted away (more to the right) from the side of the skateboard and eliminating or reducing wheel bite.

The offset axle109configuration also provides additional stability to the skateboard. When shifting the rider's weight to one side of the board, the shifted axel midpoint or truck center of gravity helps to offset the shifted center of gravity of the rider. Since the truck is configured with two pivot assemblies, the axle109and wheels139move in the direction the rider is leaning allowing the center of gravity of the truck to remain under the rider giving him much more stability while turning the skateboard.