Skateboards with multi-wheel truck

Abstract

To provide a moving wheel platform that minimizes wheel interactions with noncontinuous and uneven surfaces to enhance an individual's riding experience and satisfaction.SOLUTION: A multi-wheel truck minimizes wheel interactions with discontinuous and uneven surfaces. The truck provides a suspension system that absorbs impact force caused by uneven surfaces, and a unique attack angle that allows obstacles to be traversed when approached from a wide range of angles. A truck 100 that comprises a unique suspension system and an attack angle α that allow the truck to smoothly pass over discontinuous surfaces comprises a plurality of wheel sets comprising a rotating level arm 110 and a plurality of wheels, and further comprises a hanger 102 that serves to connect the plurality of wheel sets. The truck 100 further comprises a baseplate 170 configured to receive the hanger 102 and couple the truck 100 to the underside of a skateboard deck.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to skateboards, and more particularly to multi-wheel skateboard trucks.

[0002] (Related application data) This disclosure claims the benefit of U.S. Patent Application No. 63 / 045,582, filed June 29, 2020, and U.S. Patent Application No. 63 / 201,491, filed April 30, 2021, the contents of all of which are incorporated by reference herein in their entireties. [Background technology]

[0003] People ride and use skateboards as a convenient and recreational means of transportation. Generally, skateboards (or motorized versions thereof) offer many advantageous advantages over other self-propelled transportation alternatives because they can be easily stored, lifted, and transported. However, very often, when a user rides a skateboard over an uneven or irregular surface, including cracks, contraction joints, expansion joints, control joints, bumps, etc. (this is not an exhaustive list), the impact between the wheels and the uneven surface exerts undesirable forces on the skateboard. This impact force has harmful effects, including noise, impact to the rider, loss of speed, and loss of control of the skateboard, including rollovers and collisions. There is a need in the art for a mobile wheeled platform that minimizes wheel interaction with uneven and irregular surfaces to improve people's riding comfort and satisfaction. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 is a perspective view of a multi-wheel skateboard truck according to one embodiment.

[0005] [Figure 2] FIG. 2 is an exploded view of the truck of FIG. 1.

[0006] [Figure 3]FIG. 2 is an exploded view of a wheel set of the truck of FIG. 1.

[0007] [Figure 4] 2 is a top view of the truck of FIG. 1 forming an angle of attack according to the present invention;

[0008] [Figure 5] FIG. 4 shows the dimensions and spacing of the wheel sets shown in FIG. 3, viewed from above.

[0009] [Figure 6] FIG. 4 is a diagram showing the dimensions and spacing of the wheel sets shown in FIG. 3, as viewed from the side.

[0010] [Figure 7] 1 is a top view of a multi-wheel truck according to one embodiment, including an angle of attack approaching an obstacle at a particular angle of approach.

[0011] [Figure 8] 8 is a top view of the multi-wheel truck of FIG. 7 approaching an obstacle at an alternative approach angle.

[0012] [Figure 9] 2 is an exploded view of a level arm and corresponding spring insert according to the embodiment of FIG. 1.

[0013] [Figure 10] FIG. 2 is an exploded view of the level arm, spring insert, and hanger of the truck of FIG. 1.

[0014] [Figure 11] 1 is a view of a spring insert according to one embodiment of a multi-wheel truck.

[0015] [Figure 12] 10A-10C are views of spring inserts according to alternative embodiments of multi-wheel trucks.

[0016] [Figure 13] 10 is a view of a spring insert according to another alternative embodiment of a multi-wheel truck. FIG.

[0017] [Figure 14] 2 is a top view of a hanger for a truck according to the embodiment of FIG. 1.

[0018] [Figure 15] FIG. 15 is a perspective view of the hanger of FIG. 14.

[0019] [Figure 16] 2 is a perspective view of a base plate of the truck according to the embodiment of FIG. 1;

[0020] [Figure 17] FIG. 2 is an exploded view of the hanger and base plate assembly of the truck of FIG. 1.

[0021] [Figure 18] FIG. 10 is a perspective view of a level arm for a multi-wheel truck according to an alternative embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] I. ESSENCE OF THE INVENTION Described herein are multi-wheeled skateboard trucks configured to smoothly traverse discontinuous surfaces of various shapes and sizes at various speeds and in a wide range of directions. Presented below are embodiments of multi-wheeled skateboards with trucks that offer a unique suspension mechanism and unique placement of training wheels and center wheels to provide a unique angle of attack across discontinuous surfaces. The unique suspension system, combined with the truck wheel angle of attack, minimizes shocks associated with wheel-to-obstacle or discontinuous surface interaction. The suspension system includes multiple wheel sets, each wheel set including a center wheel, multiple training wheels, and a rotatable level arm connecting the wheels. The training wheels are attached to front and rear regions 116 of the rotatable level arm and are configured to move up and down as the level arm rotates in response to an obstacle. In many embodiments, the suspension system further includes a spring mechanism 130 configured to manage the rotation of the level arm. The truck's angle of attack is shaped by the configuration of the wheels within each wheel set. Specifically, the angle of attack depends on the spatial placement of the training wheels relative to the center wheel. The wheel space arrangement and angle of attack allow the truck to smoothly traverse obstacles when approaching such obstacles from a wide range of directions.

[0023] The multi-wheel trucks may be used in a variety of applications other than skateboards. For example, in some embodiments, the trucks may be used in pushcarts, industrial carts, industrial dollies, commercial carts, commercial dollies, hand trucks, stack trucks, skateboard trucks, longboard trucks, powered skateboard trucks, carriages, strollers, and / or luggage. Alternatively, the devices, methods, and products described herein may be applicable to other types of applications requiring a truck or other mobile wheeled platform to glide, hoover, and / or maneuver over obstacles or foreign objects (i.e., rocks, pebbles, cracks, and / or shrink joints in sidewalks).

[0024] As used herein, the terms or phrases "connect," "connected," "connect," and "connecting" may be defined as joining two or more elements mechanically or otherwise. The connecting (whether mechanical or not) may be for any length of time, for example, permanent or semi-permanent, or may be momentary.

[0025] As used herein, the terms or phrases "coupled," "coupled," "couple," and "connecting" may be defined as a relationship between two or more elements in which at least one element influences another element. The coupling (whether mechanical or otherwise) may be for any length of time, for example, permanent or semi-permanent, or may be momentary.

[0026] The terms or phrases "fixed," "fixed," "fixing," and "fixing" as used herein may be defined as to securely fasten or fasten (one or more elements) so that they cannot be moved or loosened. The fixing (whether mechanical or not) may be for any length of time, for example, permanent or semi-permanent, or may be momentary.

[0027] The terms or phrases "coupled," "coupled," "couple," and "coupling," as used herein, may be defined as connecting two or more elements mechanically or otherwise. The coupling (whether mechanical or not) may be for any length of time, e.g., permanent or semi-permanent, or momentary. Mechanical coupling, etc., should be understood broadly and include all types of mechanical coupling. The absence of words such as "removably," "removable," etc., adjacent to words such as "coupled," does not imply that the coupling in question is removable or non-removable.

[0028] As used herein, the term or phrase "skateboard" may be defined as a rideable device. A skateboard may be defined by four distinct sections. The top of the skateboard is defined as the portion of the deck on which the user stands. The bottom of the skateboard is defined as the portion opposite the top. A right-handed user's conventional stance is defined as the left foot being in front of the right foot. The front of the skateboard is defined as being proximal to the user's left foot. The rear of the skateboard is defined as being proximal to the user's right foot. The forward direction is defined as the direction of travel of the skateboard when the right foot strikes the ground backward, propelling the skateboard in the opposite direction. Similarly, when a multi-wheeled truck of the present invention is attached to the deck of the skateboard, the front portion of the multi-wheeled truck may be defined as the portion of the truck located closest to the front portion of the skateboard, and the rear portion of the truck may be defined as the portion of the truck located closest to the rear portion of the skateboard.

[0029] The terms or phrases "ground" or "rolling surface" as used herein may be defined as the surface on which skateboard wheels typically roll. The ground or rolling surface is generally considered to be a smooth surface during typical skateboard operation. However, in certain locations, the ground or rolling surface may include discontinuities or obstacles, such as cracks, ridges, expansion joints, or foreign objects, that create portions of the ground or rolling surface that are not smooth.

[0030] The terms "first," "second," "third," "fourth," etc., used in the specification and claims, if any, are used to distinguish between similar elements and not necessarily to describe a particular sequential or chronological order. It is to be understood that terms so used may be interchanged under appropriate circumstances, for example, so that the embodiments described herein are capable of operating in orders other than those illustrated or otherwise described herein. Furthermore, the terms "comprise" and "have," and any conjugations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that includes a list of elements is not necessarily limited to those elements and may include other elements not expressly listed or inherent in such process, method, system, article, device, or apparatus.

[0031] Terms such as "left," "right," "front," "rear," "top," "bottom," "upper," "lower," and the like, if any, used in this specification and claims are used for descriptive purposes and are not necessarily used to describe permanent relative positions. It is to be understood that terms so used are interchangeable under appropriate circumstances, such that the device, method, and / or article embodiments described herein are operable, for example, in other orientations other than those illustrated or otherwise described herein.

[0032] "A," "an," "the," "at least one," and "one or more" are used interchangeably to indicate the presence of at least one of an item; more than one such item may be present unless the context clearly dictates otherwise. All numerical values ​​of parameters (e.g., amounts or conditions) in this specification, including the appended claims, should be understood to be modified in all instances by the term "about," regardless of whether "about" actually precedes the numerical value. "About" indicates that the stated numerical value allows for some slight imprecision (some proximity to the precision of the value, approximately close to or reasonably close to the value, approximately equal to the numerical value). Unless otherwise understood in the art, the imprecision provided by "about" in its ordinary sense, as used herein, at least accounts for the variation that can result from normal measurement and normal usage of such parameters. Furthermore, the disclosure of a range includes the disclosure of all values ​​and sub-ranges within the entire range. Each value within a range and the endpoints of a range are all disclosed herein as separate embodiments. The terms "comprises," "comprising," "including," and "having" are inclusive and thus specify the presence of stated items but do not exclude the presence of other items. As used herein, the term "or" includes any and all combinations of one or more of the listed items. Where terms such as first, second, third, etc. are used to distinguish various items from one another, these designations are merely for convenience and do not limit the items to a particular order or sequence.

[0033] In many examples as used herein, the term "approximately" may be used when comparing one or more values, ranges of values, relationships (e.g., position, orientation, etc.), or parameters (e.g., velocity, acceleration, mass, temperature, spin rate, spin direction, etc.) to one or more other values, ranges of values, or parameters, respectively, and / or when describing a condition (e.g., with respect to time), such as a condition of remaining constant with respect to time. In these examples, use of the term "approximately" means that the value, range of values, relationship, parameter, or condition is within ±0.5%, ±1.0%, ±2.0%, ±3.0%, ±5.0%, and / or ±10.0%, as applicable, of the associated value, range of values, relationship, parameter, or condition.

[0034] Before any embodiments of the present disclosure are described in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0035] Described below are embodiments of a multi-wheel truck. Figures 1-2 illustrate an embodiment of the truck 100 with a unique suspension system and angle of attack α that allows the truck 100 to smoothly traverse discontinuous surfaces. Generally, the truck 100 includes multiple wheel sets that include a rotating level arm 110 and multiple wheels. The truck 100 further includes a hanger 102 that serves to connect the multiple wheel sets. The truck 100 further includes a base plate 170 that is configured to receive the hanger 102 and couple the truck 100 to the underside of a skateboard deck (not shown). The configuration of the hanger 102 and base plate 170 is described in more detail below.

[0036] II. Suspension System The multiple wheel sets form a suspension system that absorbs unwanted shocks during collisions with obstacles and smoothly overcomes such obstacles. FIG. 3 illustrates wheel sets for the present truck 100. In many embodiments, each wheel set includes a rotatable level arm 110 coupled to a central axle 108, at least one center wheel 120 rotatably coupled to the central axle 108, and multiple auxiliary wheels coupled to the level arm 110 by multiple auxiliary axles. In many embodiments, each wheel set includes one center wheel 120 and two auxiliary wheels, including a leading wheel 122 and a trailing wheel 124. In many embodiments, the truck 100 includes a pair of wheel sets attached to opposite ends of the hanger 102, one on each side of the truck 100. In many embodiments, each wheel set of the pair is attached to either end of the hanger 102 and lies along a longitudinal axis 1000 extending from the first end 104 of the hanger 102 to the second end 106 of the hanger 102.

[0037] The center axle 108 is coupled to one end of the hanger 102 and is configured to mount both the center wheel 120 and the rotatable level arm 110. The center axle 108 may be received by and fixedly coupled to a cavity 156 formed in the end of the hanger 102. In many embodiments, the center wheel 120 defines a hole. The hole is sized to allow the center wheel 120 to couple to the center axle 108 and rotate freely thereabout. This allows the skateboard to roll smoothly and safely along the center wheel 120 during use.

[0038] The level arm 110 is also rotatably coupled to the central axle 108. The level arm 110 includes a front region 112 located near the front of the truck 100 (i.e., the portion of the truck 100 closest to the front of the skateboard), a middle region 114 in the center of the central axle 108, and a rear region 116 opposite the front region 112 and located near the rear of the truck 100. The middle region 114 is located substantially in the center of the level arm 110 and includes an intermediate bore 115 configured to concentrically couple, attach, and / or couple to the central axle 108. The intermediate bore 115 allows the level arm 110 to couple to and rotate about the central axle 108. In the illustrated embodiment, training wheels are attached to either end of the level arm 110 by a plurality of auxiliary axles 126, 128. As shown in FIG. 3, the front region 112 is configured to receive a leading wheel 122. The front region 112 includes a front bore 113 configured to concentrically couple, mount, and / or couple a front auxiliary axle 126 (hereinafter, the “front axle”). The front axle 126 is fixedly coupled within the front bore 113, thereby restricting the front axle 126 from rotating relative to the level arm 110. The leading wheel 122 is configured to attach to the front axle 126 and is allowed to rotate freely on the front axle 126. As shown in FIG. 3 , the rear region 116 is configured to receive the trailing wheel 124. The rear region 116 includes a rear bore 117 configured to concentrically couple, mount, and / or couple a rear auxiliary axle 128 (hereinafter, the “rear axle”). The rear axle 128 is fixedly coupled within the rear bore 117, thereby restricting the rear axle 128 from rotating relative to the level arm 110. The trailing wheel 124 is configured to be attached to the rear axle 128 and is allowed to rotate freely on the rear axle 128. The configuration of the leading and trailing wheels 122, 124 attached to either end of the level arm 110 by a plurality of auxiliary axles 126, 128 allows the leading and trailing wheels 122, 124 to roll freely along the ground when the skateboard is in use.The location of the auxiliary axles 126, 128 to which the leading and trailing wheels 122, 124 are attached allows the leading and trailing wheels 122, 124 to move up and down as the level arm 110 rotates about the central axle 108.

[0039] The suspension system creates a "lifting effect" that allows the truck 100 to smoothly move over obstacles or discontinuities in the rolling surface. As the truck 100 rolls along the ground, the level arm 110 can rotate in response to the surface discontinuities. The rotation of the level arm 110 allows the training wheels on either end of the level arm 110 to rise or lower in response to the topography of the rolling surface. The freedom of the training wheels to rise or lower in response to obstacles helps absorb the shock typically associated with a collision between the wheels and such obstacles.

[0040] The lifting effect also helps dynamically distribute the load between the center wheel and the auxiliary wheels during use, providing a smoother ride. During normal use of a skateboard rolling along a smooth surface, the center wheel 120 may support most of the rider's weight. However, if the center wheel 120 encounters an obstacle, such as a crack, the leading wheel 122 and / or trailing wheel 124 may support most of the rider's weight to keep the truck 100 stable. For example, upon impact with a crack in the rolling surface, the leading wheel 122 encounters the crack first. When the leading wheel 122 is in the crack, the level arm 110 may rotate to lower the leading wheel 122 into the crack. Meanwhile, most of the skateboard's load is supported by the center wheel 120, which continues to roll along the main rolling surface. When the leading wheel 122 exits the crack, the center wheel 120 may enter the crack. The level arm 110 may rotate to raise the leading wheel 122, allowing it to continue rolling along the main rolling surface. Rather than falling into the crack and slowing the board or impacting the rider, the center wheel 120 may be suspended above the crack by the level arm 110. Because the level arm is supported on either end by the leading and trailing wheels 122, 124 rolling on a smooth rolling surface, essentially the entire load of the skateboard is supported between the training wheels, with little or no load carried by the center wheel 120. Once the center wheel 120 exits the crack, the trailing wheel 124 may enter the crack. Once the trailing wheel 124 is in the crack, the level arm 110 may rotate to lower the trailing wheel into the crack. Meanwhile, most of the board's load is supported by the center wheel 120, which is again rolling along the primary rolling surface. Because there is at least one wheel rolling along the primary rolling surface and supporting most of the rider's weight at all times, the suspension system provides stability to the truck 100 by allowing the wheelset to act like a single wheel continuously rolling along a smooth surface.

[0041] III.Angle of attack The truck 100 further comprises a spacing between multiple wheels that works in conjunction with a suspension system to provide smooth traversal of obstacles and discontinuous surfaces. The wheel spacing allows the lifting effect of the suspension system to occur regardless of the angle at which the skateboard encounters an obstacle. In many embodiments, the center and auxiliary wheels are spaced apart both laterally (i.e., in a direction extending along the longitudinal axis 1000) and fore-aft. This wheel spacing provides the truck 100 with a wide base and prevents all of the wheels in each given wheelset from striking an obstacle simultaneously. Therefore, there is always at least one wheel of every given wheelset supporting the rider's weight in its primary rolling surface. The spatial relationship between the wheels in a given wheelset may be characterized by an angle of attack α, which will be described in detail below.

[0042] The angle of attack α characterizes the spatial relationship between the center and auxiliary wheels of the truck 100. As shown in FIG. 4 , the angle of attack α may be defined as the acute angle between a first reference line A connecting the center and leading wheels 120 and 122 of a particular wheel set and a second reference line B extending parallel to the longitudinal axis 1000. The first reference line A may connect a first reference point R1 located on the leading wheel 122 and a second reference point R2 located on the center wheel 120. The first reference point R1 is the forward-most and outermost point of the leading wheel 122 (i.e., furthest from the hanger 102). Similarly, the second reference point R2 is the forward-most and outermost point of the center wheel 120. Different configurations for the leading and center wheels 120 may change the relationship between the first and second reference points R1 and R2, thereby changing the direction of the first reference line A.

[0043] Because the angle of attack α is relative to the positions of the first and second reference points R1 and R2, the angle of attack α depends on the size and location of the center wheel 120 and the leading wheel 122. Specifically, various specific configurations of the center wheel 120 and the leading wheel 122 with respect to the lateral spacing between the center wheel 120 and the leading wheel 122, the longitudinal spacing between the center wheel 120 and the leading wheel 122, the width of the center wheel 120 and the leading wheel 122, and the diameter of the center wheel 120 and the leading wheel 122 will produce various angles of attack α. Thus, the angle of attack α may be manipulated by changing the spatial relationship between the leading wheel 120 and the center wheel 120 and / or by changing the diameter and / or width of the leading wheel 122 and the center wheel 120. For example, providing a greater lateral distance between the leading wheel 122 and the center wheel 120 will produce a shallower angle of attack α, while providing a smaller lateral distance between the leading wheel 122 and the center wheel 120 will produce a steeper angle of attack α. Similarly, changing the diameter and / or width of one or more wheels in a wheelset changes the position of the first reference point R1 and / or the second reference point R2, which in turn changes the orientation of the first reference line A. The diameters and widths of multiple wheels are described in more detail below.

[0044] In many embodiments, the center wheel 120 is laterally spaced apart from the training wheels to generate the angle of attack α. Typically, the training wheels are configured in an “in-line” configuration, with the leading wheel 122 and trailing wheel 124 aligned in a straight line from the front to the rear of the truck 100. The center wheel 120 is not aligned with the training wheels, but rather is laterally spaced apart from them. In many embodiments, as shown in FIG. 5 , the center wheel 120 is laterally spaced further away from the hanger 102 than the training wheels, thereby positioning the training wheels between the center wheel 120 and the hanger 102. In an alternative embodiment (not shown), the center wheel 120 is laterally closer to the hanger 102 than the training wheels, thereby positioning the center wheel 120 between the training wheels and the hanger 102. The lateral spacing between the training wheels, particularly between the leading wheel 122 and the center wheel 120, relative to one another may be characterized by the distance between a pair of planes. The leading wheel 122 and the center wheel 120 may each lie on a respective plane that is longitudinally spaced a particular distance apart. FIG. 5 shows a first plane 2000 extending in the fore-aft direction through the center of the center wheel 120. Similarly, a second plane 3000 is shown, which extends in the fore-aft direction through the center of the leading wheel 122 (and is therefore parallel to the first plane 2000). In many embodiments, the distance P1 between the first plane 2000 and the second plane 3000 is approximately 2.0 inches. In some embodiments, the distance P1 between the first plane 2000 and the second plane 3000 may be in the range of approximately 0.5 inches to 3.0 inches. In some embodiments, the distance P1 between the first plane 2000 and the second plane 3000 is in the range of about 0.5 inches to 1.0 inches, about 1.0 inches to 1.5 inches, about 1.5 inches to 2.0 inches, about 2.0 inches to 2.5 inches, or about 2.5 inches to 3.0 inches. The distance between the planes 2000 and 3000 creates a wheelset in which the center wheel 120 is laterally spaced from the auxiliary wheels. This configuration creates the desired angle of attack α and a wide base for the wheelset.

[0045] The angle of attack α is further determined by the longitudinal distance between adjacent wheels. FIG. 6 shows a longitudinal distance 192 defined between the leading wheel 122 and the center wheel 120, where the distance 192 is measured as the perpendicular distance between the axles on which the respective wheels are mounted (i.e., the front axle 126 and the center axle 108). Similarly, the longitudinal distance 194 between the center wheel 120 and the trailing wheel 124 may be measured as the perpendicular distance between the center axle 108 and the rear axle 128 on which the respective wheels are mounted. In many embodiments, the longitudinal distances 192, 194 between adjacent wheels depend on the longitudinal length of the level arm 110, since the leading wheel 122 and the trailing wheel 124 are mounted proximate to either end of the level arm 110.

[0046] In many embodiments, the longitudinal distance between any pair of adjacent wheels may be approximately 1.5 inches. In some embodiments, the longitudinal distance between any pair of adjacent wheels may be approximately 0.5 inches to 2.5 inches. In some embodiments, the longitudinal distance between adjacent wheels may be 0.5 to 1.0 inches, 1.0 to 1.5 inches, 1.5 to 2.0 inches, or 2.0 to 2.5 inches. In some embodiments, the longitudinal distance between adjacent wheels may be 0.5 to 0.75 inches, 0.75 to 1.0 inches, 1.0 to 1.25 inches, 1.25 to 1.5 inches, 1.5 to 1.75 inches, 1.75 to 2.0 inches, 2.0 to 2.25 inches, or 2.25 to 2.5 inches. In many embodiments, the longitudinal distance 192 between the leading wheel 122 and the center wheel 120 may be substantially similar to the longitudinal distance 194 between the center wheel 120 and the trailing wheel 124. In another embodiment, the longitudinal distance 192 between the leading wheel 122 and the center wheel 120 may be substantially different from the longitudinal distance 194 between the center wheel 120 and the trailing wheel 124. The longitudinal distance between adjacent wheels determines, in part, the location of the first and second reference points R1 and R2, and thus affects the angle of attack α.

[0047] The configuration of the center wheels 120 and the leading wheels 122, with respect to both the spacing and size of each wheel, defines the angle of attack α of the truck 100. In many embodiments, an angle of attack α between 30 and 60 degrees is desirable to allow the truck 100 to smoothly traverse obstacles at the widest range of angles. In many embodiments, the angle of attack α of the truck 100 is approximately 45 degrees. In some embodiments, the angle of attack α is approximately 30 to 60 degrees. In some embodiments, the angle of attack α is approximately 30 to 35 degrees, approximately 35 to 40 degrees, approximately 40 to 45 degrees, approximately 45 to 50 degrees, approximately 50 to 55 degrees, or approximately 55 to 60 degrees. In other embodiments, the angle of attack α is between about 30 degrees and 32 degrees, between about 32 degrees and 34 degrees, between about 34 degrees and 36 degrees, between about 36 degrees and 38 degrees, between about 38 degrees and 40 degrees, between about 40 degrees and 42 degrees, between about 42 degrees and 44 degrees, between about 44 degrees and 46 degrees, between about 46 degrees and 48 degrees, between about 48 degrees and 50 degrees, between about 50 degrees and 52 degrees, between about 52 degrees and 54 degrees, between about 54 degrees and 56 degrees, between about 56 degrees and 58 degrees, or between about 58 degrees and 60 degrees.

[0048] An optimized angle of attack α improves the ability of the truck 100 to smoothly traverse obstacles of various sizes when approaching such obstacles from a wide range of angles. As shown in FIGS. 7 and 8 , an approach angle β may be defined between the truck 100 and an obstacle 190 as the skateboard approaches the obstacle 190. The approach angle β may be defined as the acute angle between the obstacle 190 and the direction of travel of the skateboard. More specifically, the approach angle β is formed by a reference line C corresponding to the direction of travel at the moment the truck 100 impacts the obstacle 190 and a second reference line D tangent to the obstacle 190 at the point of impact. For example, a skateboard approaching an elongated obstacle 190 “straight on” will define an approach angle β of approximately 90 degrees, while a skateboard approaching the obstacle 190 from any direction other than straight on will define an approach angle β that is substantially less than 90 degrees.

[0049] The angle of attack α of the truck 100 allows the truck 100 to smoothly traverse obstacles and discontinuous surfaces at a wider range of approach angles β than a conventional skateboard. Because the angle of attack α is created by the lateral spacing of the center wheel 120 and the leading wheel 122, the truck 100 effectively has a wider bottom surface than a similar board with an in-line wheel configuration or a conventional skateboard that does not create an angle of attack. The angle of attack reduces the likelihood that multiple wheels in a set will simultaneously strike an obstacle. This provides balance and stability on obstacles of various sizes and orientations by allowing at least one wheel in each wheelset to always contact the normal rolling surface. In other words, the angle of attack α allows the lifting effect to occur at a wider range of approach angles β.

[0050] When the truck 100 encounters an obstacle at any approach angle β, the load generated by the rider's weight can shift both forward and backward between the center wheel 120 and the auxiliary wheels. This configuration provides the truck 100 with two levels of stability greater than conventional skateboard trucks with only a single wheel on each side of the truck 100. When a conventional truck encounters an obstacle, the load generated by the rider's weight cannot shift away from the wheels, and therefore the wheels bear the entire force of the collision with the obstacle. In contrast, the ability to shift load between the center wheel 120 and the auxiliary wheels allows the truck 100 to absorb the force of the collision with the obstacle. The truck 100's ability to shift load in multiple directions depending on the angle of attack α provides greater absorption of this force over a wider range of approach angles β.

[0051] The lifting effect allows the truck 100 to smoothly traverse obstacles due to the lifting of the leading and trailing wheels 122, 124 on the leveling arm 110, which rotate about the central axle 108. However, in some situations, such as when a skateboard is being carried rather than ridden, it may be desirable to selectively limit the rotation of the leveling arm 110. Doing so can prevent the leveling arm 110 from freely swinging back and forth while the skateboard is being carried, which could result in the wheels striking the underside of the skateboard. Now, referring to FIGS. 9-10 , the leveling arm 110 may include a spring mechanism 130 that provides a certain amount of mechanical interference to control the rotation of the leveling arm 110 about the axle. In many embodiments, the spring mechanism 130 may include an insert recess 132 formed in the leveling arm 110 and configured to receive a spring insert 140. The spring insert 140 may be configured to engage and interface with one or more components of the track 100 to create a "spring effect" that provides resistance to rotation of the level arm 110 under a particular load. The insert recess 132 may be formed in the intermediate region 114 of the level arm 110 and may be centrally located in the intermediate bore 115 of the level arm 110. In this manner, the intermediate bore 115 may extend through a portion of the insert recess 132, and the central axle 108 may extend through the entire insert recess 132. Preferably, the insert recess 132 is formed inward from the inward-facing surface of the level arm 110 (i.e., the side of the level arm 110 that faces the hanger 102 when the level arm 110 is attached to the central axle 108). The spring inserts 140 are positioned and oriented to expose the corresponding spring inserts 140 toward the ends of the hanger 102 and are shaped so that the spring inserts 140 engage and provide the desired spring effect.

[0052] The insert recess 132 may receive a spring insert 140 configured to generate a spring effect that manages rotation of the level arm 110 about the axle. The spring insert 140 may be secured within the recess by using mechanical fasteners, such as screws or snap-fit ​​mechanisms, by using adhesives, or a combination thereof. The spring insert 140 is designed to provide a specific amount of resistance to rotation of the level arm 110 to maintain the position of the level arm 110 when the skateboard is carried. Maintaining the position of the level arm 110 when the skateboard is carried through the air protects the skateboard by preventing the training wheels from striking the skateboard deck. The spring insert 140 may be configured to allow rotation of the level arm 110 under relatively heavy loads, while limiting rotation of the level arm 110 under relatively light loads. For example, the spring insert 140 may limit rotation of the level arm 110 under light loads typically associated with a user carrying a skateboard rather than riding it. The spring insert 140 may also allow the level arm 110 to rotate under heavy loads experienced when the skateboard is ridden over an obstacle.

[0053] In many embodiments, as shown in FIGS. 9 and 10 , the spring insert 140 is a single, substantially flat piece and is configured to correspond to the shape of the insert recess 132 so that the spring insert 140 seats snugly within the insert recess 132. The spring insert 140 may be formed from a generally flexible material, such as injection-molded plastic. The spring insert 140 may be composed of any one or combination of nylon, polypropylene, polyethylene, thermoplastic, thermoplastic polyurethane, thermoset, aromatic diisocyanate, toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), acrylonitrile butadiene styrene (ABS), acetal, steel, steel alloy, or any material suitable for providing the spring insert 140 with the desired shape and properties. It is desirable for the spring insert 140 to be formed from a material with a high elongation rate. A high elongation rate allows the spring insert 140 to easily flex and “rebound.” A high elongation material allows the spring insert 140 to flex or bend in response to forces associated with use of the truck 100 .

[0054] In many embodiments, the spring insert 140 is configured to engage a portion of the hanger 102. As shown in FIG. 10 , the hanger 102 includes a shoulder 150 at each of its first and second ends, to which the central axle 108 is attached. The spring insert 140 is disposed within the level arm 110 so as to fit onto the shoulder 150 of the hanger 102. The shoulder 150 and the spring insert 140 may have complementary shapes that together create a desired spring effect when a force is applied to the level arm 110. The spring insert 140 includes an internal shape configured to engage with the shoulder 150 and act as a spring. The internal shape may include a plurality of openings, extensions, bends, slots, grooves, notches, and / or any other feature configured to engage with the central axle 108 and / or hanger 102 in a manner that creates the desired spring effect. In many embodiments, the internal shape may take the form of a cutout that extends through the entire thickness of the spring insert 140, thereby forming one or more openings. In many embodiments, the shoulder 150 may be generally cylindrical. In some embodiments, the shoulder 150 comprises one or more notches configured to interact with one or more features of the spring insert shape to provide resistance.

[0055] 11 , the spring insert 140 includes a periphery 141 defining a central opening 142 therein, a plurality of protrusions 144, and a plurality of bumper portions 146. The protrusions 144 may extend inward from the periphery 141 of the spring insert 140 toward the central opening 142. In many embodiments, the protrusions 144 are configured to fit within corresponding notches 152 formed in a shoulder 150 of the hanger 102. For example, in the embodiment shown, the protrusions 144 of the spring insert 140 are generally triangular in shape and are configured to mate with generally triangular notches 152 (as shown in FIG. 10 ) formed in the shoulder 150. During use of the truck 100 (either riding or carrying the skateboard), loads on the level arm 110 cause the protrusions 144 to press against the surface of the shoulder 150, providing resistance to rotation. However, the flexibility of the spring insert material will allow protrusion 144 to flex, allowing the arm to rotate under sufficient load. In many embodiments, spring insert 140 includes a notch 148 formed on the opposite side of protrusion 144. Notch 148 in spring insert 140 may provide a small space between periphery 141 of spring insert 140 and insert recess 132 so that the insert is not flush within the recess at the specific location of notch 148. The space created by notch 148 provides greater ability for protrusion 144 to flex upon engagement with shoulder 150.

[0056] The spring insert 140 further includes a plurality of bumper portions 146 that act as guides to keep the spring insert 140 centered on the shoulder 150 of the hanger 102 while the truck 100 is in use, thereby providing stable rotation of the level arm 110. In many embodiments, while the bumper portions 146 abut a portion of the shoulder 150, the contact area between the shoulder 150 and the bumper portions 146 is minimized during normal use of the skateboard, thereby not inhibiting rotation of the level arm 110. Rather, the protrusions 144 provide the primary contact area between the spring insert 140 and the shoulder 150. Under sufficient load, the protrusions 144 flex, allowing the level arm 110 to rotate, and the bumper portions 146 help keep the spring insert 140 centered.

[0057] The spring insert 140 may further include a pair of mounting holes 149 located proximate the periphery 141. The mounting holes 149 may be configured to receive mechanical fasteners (such as screws) and provide locations where the spring insert 140 should be mounted within the level arm 110 by such mechanical fasteners.

[0058] FIG. 12 illustrates an alternative embodiment of a spring insert 240 according to the present invention. The spring insert 240 is similar to the spring insert 140 and has substantially the same shape. The spring insert 240 also serves the same function as the spring insert 140; upon engagement with the shoulder 150 of the hanger 102, a portion of the spring insert's shape is configured to provide resistance to rotation but still flex and allow rotation under a sufficient load. Rather than protrusions extending inward toward the opening 242, the spring insert 240 includes a pair of elongated, bent portions 244 extending laterally across the insert. The bent portions 244 may be substantially thinner than the rest of the insert, thereby allowing the bent portions 244 to flex upon engagement with the shoulder 150 of the hanger 102. Similar to the notch 148 of the spring insert 140, the bent portion 244 of the spring insert 240 may form a space between the periphery 241 of the spring insert 240 and the insert recess 132. This space allows the bent portion 244 to bend outward when the shoulder 150 presses against the bent portion 244. Under sufficient load, the bent portion 244 bends enough to allow rotation of the level arm 110. In many embodiments, the spring insert 240 further includes a plurality of bumper portions 246 and mounting holes 249 similar to those of the spring insert 140.

[0059] FIG. 13 illustrates another alternative embodiment of a spring insert 340 according to the present invention. The spring insert 340 is similar to the spring inserts 140 and 240 and includes substantially similar features. The spring insert 340 also serves the same function as the spring inserts 140 and 240; when the spring insert 340 engages the shoulder 150 of the hanger 102, the shape of the portion of the spring insert is configured to provide resistance to rotation while still flexing to allow rotation under a sufficient load. The spring insert 340 includes a plurality of elongated protrusions 344 extending away from the periphery 341 and configured to engage portions of the shoulder 150. The spring insert 340 further includes slots 345 separating the elongated protrusions 344 from the periphery 341. The slots 345 allow the elongated protrusions 344 to flex outward toward the periphery 341 when the shoulder 150 presses against the elongated protrusions 344. Under a sufficient load, the elongated protrusion 344 flexes sufficiently to allow rotation of the level arm 110. The spring insert 340 further comprises a bumper portion 346 similar to the bumper portion 146 of the spring insert 140. However, instead of the bumper portion 146 creating a small contact area between the bumper portion 346 and the shoulder 150, the bumper portion 346 of the spring insert 340 may comprise an arcuate surface that corresponds to the shape of the shoulder 150 and provides a larger contact area between the bumper portion 346 and the shoulder 150. This configuration provides additional stability for centering the spring insert 340 relative to the central axle 108 and the hanger 102 while still allowing rotation of the level arm 110. In some embodiments, the spring insert 340 further comprises a plurality of gaps 347 formed between the bumper portion 346 and the elongated protrusion 344, respectively. A plurality of gaps 347 separate the bumper portion 346 and the elongated protrusion 344 from one another to allow for greater overall flex within the internal shape of the spring insert 340 .

[0060] The spring insert 140 manages the rotation of the level arm 110. When the truck 100 is on the ground, the level arm 110 may be considered to be in a "rest" position. When stationary, the level arm 110 may be approximately parallel to the skateboard deck, and the wheels may be approximately equally spaced away from the underside of the deck. When the skateboard is being transported (i.e., when the wheels are not touching the ground), the weight of the wheels exerts a force on the level arm 110, causing it to rotate away from the rest position. The shape of the spring insert 140 may engage the shape of the shoulder 150 to limit the rotation of the level arm 110, thereby holding the level arm 110 in a generally rest position. By holding the level arm 110 in a rest position and limiting its rotation, the spring mechanism 130 prevents the wheels from hitting the underside of the deck, as would occur if the level arm 110 were allowed to rotate freely when the board is being transported.

[0061] However, during use of the skateboard, it may be desirable for the level arm 110 to rotate and create a pulling effect, allowing the multi-wheel truck 100 to smoothly traverse discontinuous and uneven surfaces. The spring mechanism 130 may allow the level arm 110 to rotate during use of the skateboard. When a sufficient moment is applied to the level arm 110 during use, such as when traversing a crack or uneven surface, the force of the shoulder 150 pressing against the flexible spring insert 140 causes the spring portion to flex, thereby allowing the level arm 110 to rotate and create the desired pulling effect.

[0062] In many embodiments, the spring mechanism 130 may have a rotation threshold. The rotation threshold may be defined as the minimum force applied to the level arm 110 that causes the spring mechanism 130 to allow the level arm 110 to rotate. For example, if the force applied to the level arm 110 is less than the rotation threshold, the spring mechanism 130 limits the rotation of the level arm 110, holding the level arm 110 in a stationary position. In contrast, if the force applied to the level arm 110 is greater than the rotation threshold, the spring mechanism 130 allows the level arm 110 to rotate. The rotation threshold may depend on the design of the spring insert 140, particularly the internal geometry and materials used. Preferably, the spring insert 140 is designed so that smaller forces associated with carrying a skateboard are less than the rotation threshold, while larger forces associated with riding a skateboard over obstacles and uneven surfaces are preferably greater than the rotation threshold. In some embodiments, the rotation threshold is between approximately 0.1 foot-pounds-force and 1.5 foot-pounds-force. In some embodiments, the rotation threshold can be between about 0.1 ft-pounds-force and 0.25 ft-pounds-force, between about 0.25 ft-pounds-force and 0.5 ft-pounds-force, between about 0.5 ft-pounds-force and 0.75 ft-pounds-force, between about 0.75 ft-pounds-force and 1.0 ft-pounds-force, or between about 1.0 ft-pounds-force and 1.5 ft-pounds-force. In some embodiments, the rotation threshold can be between about 0.1 ft-pounds-force and 0.4 ft-pounds-force, between about 0.4 ft-pounds-force and 0.7 ft-pounds-force, between about 0.7 ft-pounds-force and 1.1 ft-pounds-force, or between about 1.1 ft-pounds-force and 1.5 ft-pounds-force. The rotation threshold allows the spring mechanism 130 to limit rotation of the level arm 110 under sufficiently small loads, yet allow rotation of the level arm 110 under sufficiently large loads.

[0063] In many embodiments, the spring mechanism 130 includes a spring insert 140 that is located within an insert recess 132 formed from the level arm 110. However, in alternative embodiments, rather than including a separate spring insert 140 within the level arm 110, the spring mechanism 130 may be integrally formed within the level arm 110. In other words, the level arm 110 may be formed with an integral spring shape centered within the intermediate bore 115 that provides the same spring effect as the spring insert of the above-described embodiments. In many such embodiments, the level arm 110 with the integral spring shape may be formed from a non-metallic material, such as an injection-molded plastic material or a composite material. Embodiments of lifting arms with integral spring mechanisms are discussed in further detail below.

[0064] IV. Remaining Features As described above, the multi-wheel truck 100 includes a hanger 102 and a base plate 170, which serve to couple multiple wheel sets and configure the truck 100 to be mountable to the underside of a skateboard deck. As shown in FIG. 2, the hanger 102 is configured to couple a wheel set to the truck 100, and the base plate 170 is configured to receive the hanger 102 and mount the truck 100 to the underside of a skateboard deck.

[0065] 14 and 15 illustrate an embodiment of a hanger 102 of a multi-wheeled truck 100. The hanger 102 includes a first end 104 and a second end 106 opposite the first end 104. The hanger 102 defines a longitudinal axis 1000 extending between the first end 104 and the second end 106, with the first and second ends each located proximal to the longitudinal axis 1000. The hanger 102 further defines a transverse axis 1100 extending perpendicular to the longitudinal axis 1000. Thus, the transverse axis 1100 corresponds to the fore-and-aft direction of the hanger 102 relative to the front and rear of the skateboard. In many embodiments, the first and second ends are located proximal to the front of the hanger 102, while other components of the hanger 102, such as the pivot tip 162 or pivot saddle 172, may be located rearward of the first and second ends. In many embodiments, the greatest width of the hanger 102 is located between the first and second ends, such that the front of the hanger 102 comprises the widest portion of the hanger. Because the first and second ends generally form the widest portions of the hanger 102, the wheel sets attached to the first and second ends are spaced away from the remainder of the hanger 102 and rotate freely without interference from the hanger 102.

[0066] Each of the first end 104 and the second end 106 may include a void 156 configured to couple the wheel set to the hanger 102. The void 156 is configured to receive the central axle 108 of the wheel set and fixedly attach the central axle 108 to the hanger 102. In many embodiments, the void 156 is threaded to receive a corresponding threaded portion of the central axle 108. In some embodiments, the void 156 may include any form of attachment mechanism suitable for fixedly securing a portion of the central axle 108 therein, such as a snap fit, adhesive, epoxy, magnets, an interlocking attachment mechanism, or a combination thereof.

[0067] As briefly mentioned above, the hanger 102 further includes a plurality of shoulders 150 configured to engage with the spring insert 140 of the level arm 110 upon rotation of the level arm 110. As shown in FIGS. 14 and 15 , the hanger 102 includes a shoulder 150 located at each of the first and second ends 106. In many embodiments, the shoulders 150 may protrude from the ends of the hanger 102 to be received within the internal shape of the spring insert 140. The shoulders 150 may have a shape configured to correspond to the internal shape of the spring insert 140 such that the shoulders 150 engage with the spring insert 140 upon rotation of the level arm 110 to create the spring effect described above. As shown in the embodiment of FIGS. 14 and 15 , the shape includes a generally cylindrical shape but includes a plurality of notches 152 around its periphery. Each notch 152 may be configured to receive a protrusion 144 of the spring insert 140, such as the protrusion 144 of the spring insert 140. As the level arm 110 rotates about the central axle 108, the surface of the notch 152 presses against the protrusion 144 of the spring insert 140, limiting the rotation of the level arm 110 up to a certain amount of force.

[0068] In many embodiments, the hanger 102 may be configured to pivot left or right about a portion of the base plate 170 during use to control the direction of the skateboard. As the rider shifts their weight to the right or left side of the skateboard, the hanger 102 may pivot about the base plate 170 to orient the skateboard left or right. The hanger 102 includes a pivot body 160 configured to engage with a pivot cup 164 of the base plate 170 to allow the hanger 102 to pivot. The pivot body 160 may be located rearward of the front of the hanger 102 and may have a width that is substantially less than the maximum width of the hanger 102. In many embodiments, the pivot body 160 is generally triangular in shape with rounded edges that allow the hanger 102 to pivot about the surface of the pivot cup 164.

[0069] The hanger 102 further comprises a pivot tip 162 configured to center the hanger 102 on the base plate 170. In many embodiments, the pivot tip 162 protrudes from the rearmost portion of the hanger 102. The pivot tip 162 may be received by a portion of the base plate 170, such as a pivot cup 164, which is described in further detail below. In many embodiments, the pivot tip 162 is generally cylindrical except for a capped or pointed end that allows the hanger 102 to smoothly rotate and / or pivot within the pivot cup 164. The pivot tip 162 may be integrally formed with the hanger 102, thereby forming a continuous hanger structure.

[0070] 14 , the hanger 102 includes a kingpin opening 178 that receives a kingpin 175 or another attachment mechanism to allow the hanger 102 to be coupled to one or more other components of the track 100, such as the base plate 170. The kingpin opening 178 may be a through opening that extends through a portion of the hanger body. In many embodiments, the kingpin opening 178 is located substantially in the center of the hanger 102 proximal to the pivot body 160. In many embodiments, the kingpin opening 178 is located between the pivot body 160 and the front of the hanger 102. The connection between the hanger 102 and the base plate 170 via the kingpin opening 178 is described in further detail below.

[0071] The hanger 102 may be constructed from any material used to construct a conventional skateboard truck. The hanger 102 may be constructed from any one or combination of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 1380 stainless steel, 303 stainless steel, stainless steel alloy, brushed steel, tungsten, magnesium, magnesium alloy, titanium, titanium alloy, Ti-6-4, aluminum, aluminum alloy, aluminum 2024, aluminum 3003, aluminum 5052, aluminum 6061, aluminum 7075, ADC-12, aluminum A356, magnesium AZ61A, magnesium AZ80A, magnesium AZ31B, carbon fiber reinforced plastic composite, glass filled plastic composite, nylon, polyetheretherketone, polyetherimide, polyphenylene sulfide, or any material suitable for constructing a hanger or skateboard truck. In many embodiments, the hanger 102 may be constructed from aluminum 6061, aluminum A356, or magnesium AZ61A. The material of the hanger 102 may vary based on the intended use and / or desired weight of the hanger 102.

[0072] In some embodiments, the hanger 102 may include one or more weight-reducing features 158. The weight-reducing features 158 may be provided in the form of notches, depressions, gaps, voids, holes, or the like. The weight-reducing features 158 are sections or portions of the hanger 102 that are devoid of material. The weight-reducing features 158 may be provided in any portion of the hanger 102, such as the first end 104, the second end 106, the pivot body 160, the pivot tip 162, or the like, for example, substantially proximal to the front of the hanger 102 or substantially proximal to the rear of the hanger 102. In many embodiments, the weight-reducing features 158 are provided in the pivot body 160 because the pivot body 160 is generally the most substantial portion of the hanger mass.

[0073] The lightening features 158 may occupy between about 1% and about 20% of the volume of the hanger 102. In many embodiments, the lightening features 158 may occupy between about 1% and about 5%, between about 5% and about 10%, between about 10% and about 15%, or between about 15% and about 20% of the volume of the hanger 102. In other embodiments, the lightening features 158 may occupy between about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, or about 20% of the volume of the hanger. One or more lightening features 158 enable the mass of the hanger 102 to be kept to a minimum while maintaining structural integrity.

[0074] Truck 100 further includes a base plate 170 configured to receive hanger 102 and couple truck 100 to the underside of a skateboard deck. Base plate 170 may be mechanically attached to the underside of a skateboard deck by any fastening means, such as screws, bolts, adhesive, a snap fit, or some combination thereof. In many embodiments, as shown in FIG. 16 , base plate 170 includes a plurality of openings 174 extending through the body of base plate 170 and configured to receive mechanical fasteners, such as bolts or screws. In many embodiments, each of the plurality of openings 174 is located proximal to the periphery or peripheral edge of base plate 170. Further, in some embodiments, openings 174 may be threaded to receive corresponding threaded fasteners. In some embodiments, base plate 170 may have two openings, three openings, four openings, five openings, six openings, or seven openings. In many embodiments, base plate 170 may include at least four openings 174 to provide sufficient structural rigidity for attaching base plate 170 to a skateboard deck.

[0075] Base plate 170 may be constructed from any material used to construct conventional skateboard trucks. Base plate 170 may be constructed from any one or combination of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 1380 stainless steel, 303 stainless steel, stainless steel alloy, brushed steel, tungsten, magnesium, magnesium alloy, titanium, titanium alloy, Ti-6-4, aluminum, aluminum alloy, aluminum 2024, aluminum 3003, aluminum 5052, aluminum 6061, aluminum 7075, ADC-12, aluminum A356, magnesium AZ61A, magnesium AZ80A, magnesium AZ31B, carbon fiber reinforced plastic composite, glass filled plastic composite, nylon, polyetheretherketone, polyetherimide, polyphenylene sulfide, or any material suitable for constructing a base plate or skateboard truck. In many embodiments, base plate 170 may be constructed from aluminum 6061, aluminum A356, or magnesium AZ61A. The material of the base plate 170 may vary based on the intended use and / or desired weight of the base plate 170.

[0076] The base plate 170 further includes a saddle 172 and a pivot cup 164 that extends away from the skateboard deck. The saddle 172 forms a base for the pivot body 160 of the hanger 102 to sit on and pivot around. In many embodiments, the surface of the saddle 172 is substantially flat. This allows rounded surfaces and / or rounded edges of the hanger 102 to pivot around the surface of the saddle 172. When fully assembled, the saddle 172 may be located near the front of the base plate 170 and may orient the hanger 102 so that the front of the hanger 102 is proximal to the front of the base plate 170. In many embodiments, the saddle 172 extends away from the skateboard deck at an angle, thereby orienting the hanger 102 at an angle relative to the skateboard deck. By angling the hanger 102 in this manner, the pivoting action of the hanger 102 on the saddle 172 causes the wheels to turn left or right. In this manner, the rider can control the direction of the skateboard during use by shifting their weight left or right.

[0077] The saddle 172 further includes a kingpin receiving port 176. The kingpin receiving port 176 may take the form of an opening extending through the saddle 172. The kingpin receiving port 176 is configured to receive a kingpin 175 that couples the base plate 170 to the hanger 102. In many embodiments, the kingpin receiving port 176 may be threaded or unthreaded. The geometric characteristics of the kingpin receiving port 176 (i.e., thread type, number of threads, pitch, etc.) may vary based on the type and shape of the kingpin 175.

[0078] The pivot cup 164 is formed aft of the saddle 172 and is configured to receive the pivot tip 162 of the hanger 102. The pivot cup 164 forms a cup-like structure including one or more interior walls that form a cavity. The pivot cup 164 is shaped to receive the pivot tip 162 and accommodate the pivot tip 162 within the cavity. When assembled, the pivot cup 164 helps to center the hanger 102 on the base plate 170 by retaining the pivot tip 162 within the pivot cup 164. In many embodiments, the interior walls of the pivot cup 164 may form a generally cylindrical shape that corresponds to the generally cylindrical shape of the pivot tip 162. In this manner, the pivot tip 162 may be retained within the pivot cup 164 while still being allowed to rotate within the pivot cup 164 as the hanger 102 pivots.

[0079] FIG. 17 shows a configuration in which the hanger 102 and the base plate 170 are joined together. The hanger 102 sits on a base plate 170 and is coupled by a kingpin 175. The hanger 102 sits on an angled saddle 172 that orients the hanger 102 at an angle relative to the skateboard deck. The pivot body 160 of the hanger 102 rests on the surface of the saddle 172 to allow the hanger 102 to pivot about the saddle 172. Additionally, the pivot tip 162 of the hanger 102 is inserted into a pivot cup 164 of the base plate 170 to center the hanger 102 relative to the base plate 170.

[0080] Kingpin receiving ports 176 of saddle 172 align with kingpin openings 178 of hanger 102, each configured to receive a kingpin 175. In many embodiments, kingpin 175 is a threaded, elongated screw. Kingpin 175 connects hanger 102 to the base by extending through kingpin receiving ports 176 and kingpin openings 178, respectively. In many embodiments, a threaded bolt 180 can be attached to the threaded end of kingpin 175 to lock kingpin 175 in place and secure the connection between base plate 170 and hanger 102.

[0081] As mentioned above, the multi-wheel truck 100 includes one or more level arms 110 that connect multiple wheels in a wheelset and rotate to help provide a lifting effect over obstacles and uneven surfaces. In many embodiments, the one or more level arms 110 are constructed from a metallic material, a non-metallic material, or some combination thereof. In many embodiments, the one or more level arms 110 may be constructed from any one or combination of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 1380 stainless steel, 303 stainless steel, stainless steel alloy, brushed steel, tungsten, magnesium, magnesium alloy, titanium, titanium alloy, Ti-6-4, aluminum, aluminum alloy, aluminum 2024, aluminum 3003, aluminum 5052, aluminum 6061, aluminum 7075, ADC-12, aluminum A356, magnesium AZ61A, magnesium AZ80A, magnesium AZ31B, carbon fiber reinforced plastic composite, glass filled plastic composite, nylon, polyetheretherketone (PEEK), polyetherimide, polyphenylene sulfide, or any material suitable for constructing a skateboard truck component. In many embodiments, the one or more level arms 110 may be constructed from aluminum 6061, aluminum A356, or magnesium AZ61A. In another embodiment, one or more of the level arms 110 may be constructed from nylon or carbon fiber reinforced nylon. In some embodiments, one or more of the level arms 110 may comprise a multi-part structure combining portions formed from carbon fiber reinforced plastic and plastic without carbon fiber reinforcement.

[0082] As shown in the alternative embodiment of FIG. 18 , one or more level arms 210 may have a multi-part structure including a skeleton 218 and an enclosure 219. The skeleton 218 may be an interior portion of the level arm 210 and may comprise the main structural element of the level arm, including forming the front, middle, and rear openings of the level arm 210. As such, the skeleton 218 is the only portion of the level arm that directly receives and contacts the multiple axles of the wheelset. The skeleton 218 may be formed from a high-strength material to provide support and durability to the level arm 210. In many embodiments, the skeleton 218 may be constructed from a rigid plastic, such as a carbon fiber reinforced plastic composite or a glass-filled plastic composite, a metal material, or any other material having sufficient strength to provide support and durability to the level arm 210.

[0083] The enclosure 219 surrounds and encases at least a portion of the skeleton 218. In many embodiments, the enclosure 219 is constructed of a "softer material" that has a greater elongation rate than the skeleton 218. In many embodiments, the enclosure 219 is constructed of injection-molded plastic, unfilled plastic (i.e., plastic without carbon fiber or glass reinforcement), nylon, polypropylene, polyethylene, or any other plastic or material with a desired elongation rate. The enclosure 219 can provide protection against failure of the level arm 210. For example, even if the skeleton 218, which is highly rigid due to its high strength, is damaged and cracks or fails completely, the high elasticity of the enclosure 219 allows the surrounding enclosure 219 to stretch without breaking. This configuration protects the level arm 210 from catastrophic failure.

[0084] The enclosure 219 may also be configured with an integrally formed spring mechanism 230 therein. With the ability to injection mold the enclosure 219, the enclosure 219 may be designed with a spring shape substantially similar to the shape of the spring inserts 140, 240, and 340. The inclusion of the integrally formed spring mechanism 230 within the level arm 210 itself eliminates the need for a separately formed spring insert.

[0085] As described above, the multi-wheel truck 100 includes a plurality of wheels, including at least one center wheel 120 and one or more training wheels. Each wheel may be characterized by a diameter (wheel diameter), a width (wheel width), a durometer (wheel durometer), and a material (wheel material). In many embodiments, the characteristics (diameter, width, durometer, and / or material) of the center wheel 120 may be different from the characteristics of one or more of the training wheels. In other embodiments, the characteristics of the center wheel 120 may be substantially similar to the characteristics of one or more of the training wheels.

[0086] In many embodiments, the diameter of the wheel(s) ranges from about 1.5 inches to 4.0 inches, as shown in Figure 6. In some embodiments, the diameter of the wheel(s) may range from 1.5 inches to 2.0 inches, 2.0 inches to 2.5 inches, 2.5 inches to 3.0 inches, 3.0 inches to 3.5 inches, or 3.5 inches to 4.0 inches. In some embodiments, the diameter of the wheel(s) may range from 1.5 inches to 1.75 inches, 1.75 inches to 2.0 inches, 2.0 inches to 2.25 inches, 2.25 inches to 2.5 inches, 2.5 inches to 2.75 inches, 2.75 inches to 3.0 inches, 3.0 inches to 3.25 inches, 3.25 inches to 3.5 inches, 3.5 inches to 3.75 inches, or in the range of 4.0 inches.

[0087] One or more wheels may have a substantially similar diameter relative to one other wheel, two or more wheels, three or more wheels, four or more wheels, or five or more wheels. In many embodiments, at least one center wheel 120 may have a substantially similar diameter D1 relative to one or more auxiliary wheels. In some embodiments, one or more auxiliary wheels may have a substantially similar diameter D2 relative to one or more other auxiliary wheels. For example, a leading wheel 122 of a particular wheel set may have a substantially similar diameter as a trailing wheel 124 of the same wheel set. In other embodiments, one or more auxiliary wheels may have a substantially different diameter D2 relative to one or more other auxiliary wheels. For example, a leading wheel 122 of a particular wheel set may have a substantially larger or substantially smaller diameter than a trailing wheel 124 of the same wheel set.

[0088] In alternative embodiments, one or more wheels may have a substantially different diameter relative to one other wheel, two or more wheels, three or more wheels, four or more wheels, or five or more wheels. In many embodiments, at least one center wheel 120 may have a substantially different diameter relative to one or more auxiliary wheels. In some embodiments, the diameter D1 of at least one center wheel 120 may be smaller than the diameter D2 of at least one auxiliary wheel. In some embodiments, the diameter D1 of at least one center wheel 120 may be larger than the diameter D2 of at least one auxiliary wheel. In some embodiments, one or more auxiliary wheels may have a substantially different diameter relative to one or more other auxiliary wheels. For example, the leading wheel 122 of a particular wheel set may have a substantially larger or smaller diameter than the trailing wheel 124 of the same wheel set.

[0089] The diameter of one or more wheels is important in enabling the truck 100 to smoothly traverse obstacles and discontinuous surfaces. By sizing the wheels to a sufficiently large diameter, when a given wheel encounters an obstacle, the point along the wheel that makes contact with the obstacle occurs low enough on the wheel to reduce the impact force between the wheel and the obstacle. As noted above, the diameter of one or more wheels also affects the angle of attack α. Reducing or increasing the diameter of the leading and / or center wheels 120 changes the position of reference point R1 and / or reference point R2 relative to each other. Changing the position of the reference points may change the orientation of reference line A, affecting the angle of attack α formed between reference line A and reference line B.

[0090] For example, in some embodiments, each of the wheels may have a substantially smaller diameter to provide a substantially steeper angle of attack α (i.e., an angle of attack substantially greater than 45 degrees). In other embodiments, each of the wheels may have a substantially larger diameter to provide a substantially shallower angle of attack α (i.e., an angle of attack substantially less than 45 degrees). In some embodiments, each of the wheels may have a different diameter to optimize the angle of attack α. In some embodiments, the leading wheel 122 may have the largest diameter, the center wheel 120 may have a diameter D1 smaller than the diameter of the leading wheel 122, and the trailing wheel 124 may have a smaller diameter than both the leading wheel 122 and the center wheel 120. Such embodiments with a larger leading wheel 122 diameter may provide an additional advantage when traversing obstacles. The leading wheel 122 is generally the first wheel to encounter such an obstacle, and providing a larger leading wheel 122 diameter minimizes impact between the obstacle and the leading wheel 122. As noted above, the diameter of each wheel may be balanced with the width and spacing of each wheel to optimize the angle of attack α.

[0091] In many embodiments, the wheel width for one or more wheels can range from about 0.1 inches to 2.5 inches. In some embodiments, the width for one or more wheels can be about 0.1 to 0.5 inches, 0.5 to 1.0 inches, 1.0 to 1.5 inches, 1.5 to 2.0 inches, or 2.0 to 2.5 inches. In some embodiments, the wheel width for one or more wheels can be about 0.1 to 0.25 inches, 0.25 to 0.5 inches, 0.5 to 0.75 inches, 0.75 to 1.0 inches, 1.0 to 1.25 inches, 1.25 to 1.5 inches, 1.5 to 1.75 inches, 1.75 to 2.0 inches, 2.0 to 2.25 inches, or 2.25 to 2.5 inches.

[0092] In many embodiments, the width W2 of each training wheel is substantially the same as the width of another training wheel. For example, the trailing wheels 124 and leading wheels 122 in a given wheel set generally have the same width W2. In many embodiments, the width W2 of the training wheels is approximately 0.5 inches. In many embodiments, the width W2 of one or more of the training wheels may range from approximately 0.1 to 1.5 inches. In some embodiments, the width W2 of one or more training wheels may range from approximately 0.1 to 0.3 inches, 0.3 to 0.5 inches, 0.5 to 0.7 inches, 0.7 to 0.9 inches, 0.9 to 1.1 inches, 1.1 to 1.3 inches, and 1.3 to 1.5 inches.

[0093] In many embodiments, the width W1 of the center wheel 120 is greater than the width W2 of the training wheels. In many embodiments, the width W1 of the center wheel 120 is approximately 1.7 inches. In many embodiments, the width W1 of the center wheel 120 may range from approximately 1.0 to 2.5 inches. In some embodiments, the width W1 of the center wheel 120 may be 1.0 to 1.25 inches, 1.25 to 1.5 inches, 1.5 to 1.75 inches, 1.75 to 2.0 inches, 2.0 to 2.25 inches, or 2.25 to 2.5 inches. Generally, a larger width W1 for the center wheel 120, which bears the majority of the load when the skateboard is rolling along a smooth rolling surface, not only increases the durability of the center wheel 120 but also provides improved stability for the truck 100.

[0094] The width of each of the wheels, particularly the width of the center and leading wheels 122, affects the angle of attack α. Reducing or increasing the width of the leading and / or center wheels 120 changes the location of reference points R1 and / or R2 relative to each other. Changing the location of the reference points may change the orientation of reference line A, affecting the angle of attack α formed between reference line A and reference line B.

[0095] In many embodiments, the wheel durometer for each wheel may be determined by the intended use of the wheels and the desired grip with the ground. For example, if a user requires wheels that provide sufficient grip for maneuvering over uneven or continuous surfaces, sidewalk contraction joints, cracks, pebbles, rocks, etc., the durometer of one or more wheels may be in the range of about 78A to 98A, measured on the Shore A durometer scale. In other embodiments, the durometer of one or more wheels may be about 78A to 80A, 80A to 82A, 82A to 84A, 84A to 86A, 86A to 88A, 88A to 90A, 90A to 92A, 92A to 94A, 94A to 96A, or 96A to 98A. In some embodiments, the wheel durometer may be 78A, 79A, 80A, 81A, 82A, 83A, 84A, 85A, 86A, 87A, 88A, 89A, 90A, 91A, 92A, 93A, 94A, 95A, 96A, 97A, or 98A. To achieve the desired wheel durometer, multiple wheels may be constructed from various plastic or plastic polyurethane materials with different hardness values.

[0096] In many embodiments, one or more wheels may be constructed from a material selected from the group consisting of thermoplastics, thermoplastic polyurethanes, thermosets, aromatic diisocyanates, toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), nylon, polypropylene, polyethylene, or any material suitable for constructing skateboard wheels. In some embodiments, the material of the central wheel 120 is the same as the material of the plurality of training wheels 122, 124. In other embodiments, the central wheel 120 may be constructed from a first material selected from the above group, while the plurality of training wheels 122, 124 may be constructed from a second material selected from the above group. In many embodiments, the central wheel 120 is constructed from a thermoset plastic, such as MDI, and the plurality of training wheels 122, 124 are constructed from TPU.

[0097] V. Electric Skateboard Embodiments In some embodiments (not shown), the multi-wheel truck 100 described herein may be configured to be applied to an electric skateboard. In many embodiments, the multi-wheel truck 100 may be configured to receive one or more belts connected to an electric motor. In such embodiments, the belts may connect the electric motor to a central axle 108, and the motor is configured to drive the central axle 108 via one or more belts. The electric motor powers the axles by driving the belts, which in turn rotates the axles. In such embodiments, the center wheel 120 of each wheel set may be fixedly mounted to the central axle 108 rather than rotatably mounted. In this manner, the center wheel 120 may rotate when powered by the electric motor, propelling the skateboard forward.

[0098] In another embodiment (not shown), the multi-wheel truck 100 may include one or more wheels configured to receive hub motors. Each hub motor may be enclosed inside a respective one of the center wheels 120 and coupled to the central axle 108. In such an embodiment, the hub motors may rotate about the central axle 108, providing power to the center wheels 120 and causing them to rotate. Rotation of the center wheels 120 by the hub motors may propel the skateboard forward.

[0099] In some embodiments, the multi-wheel truck 100 may be configured to receive one or more sensors in one of the wheels, one or more of the axles, the hanger 102, or the pivot saddle 172. The sensors may be in communication with the motor and may send signals that control the speed of the motor when the user steps on or shifts their weight on the board. In this manner, the user may control the speed of the skateboard by leaning forward or backward on the skateboard deck.

[0100] VI. Working Examples (1. Example 1) An exemplary skateboard truck 100 according to the present invention includes a wheelset configuration that produces an angle of attack α of 43.72 degrees. The exemplary truck 100 has a fore-aft distance 142 between the leading wheel 122 and the center wheel 120 of 1.62 inches. The exemplary truck 100 has a lateral distance P1 of 1.97 inches between a first plane 2000 on which the center wheel 120 rests and a second plane 3000 on which the leading wheel 122 rests. The leading wheel 122 has a width W2 of 0.55 inches and a diameter D2 of 2.75 inches. The center wheel 120 has a width W1 of 1.68 inches and a diameter D1 of 2.76 inches. The respective sizes and positions of the leading wheel 122 and center wheel 120 of the exemplary truck 100 determine the positions of the first reference point R1 and the second reference point R2 such that a line A connecting the first reference point R1 and the second reference point R2 forms an angle of attack α of 43.72 degrees with respect to a reference line B extending parallel to the longitudinal axis.

[0101] 2. Example 2 The deceleration over a 1.5-inch bump of an exemplary skateboard of Example 1 equipped with a multi-wheel truck (six wheels total per truck) having a spring mechanism 130 according to the present invention and level arms with an angle of attack α of 43.72 degrees was compared to a control skateboard equipped with conventional trucks lacking level arms (two wheels total per truck). The deceleration experienced by the skateboard during impact with the bump was measured by an accelerometer during each test. Table 1 below shows the results of the comparison. The greater the magnitude, the greater the deceleration and the greater the loss of speed.

[0102] [Table 1]

[0103] On average, the exemplary skateboard decelerated by 2.28 G less than the control skateboard. This reduction in deceleration for the exemplary skateboard translates to 58% less speed loss over bumps than the control skateboard.

[0104] The deceleration over a 3-inch expansion joint (or crack) of the exemplary skateboard of Example 1, equipped with a spring mechanism 130 according to the present invention and multi-wheel trucks (six wheels total per truck) with level arms having an angle of attack α of 43.72 degrees, was compared to a control skateboard equipped with conventional trucks lacking level arms (two wheels total per truck). The deceleration experienced by the skateboard during impact with the expansion joint was measured by an accelerometer during each test. Table 2 below shows the results of the comparison. The greater the magnitude, the greater the deceleration and the greater the speed loss.

[0105] [Table 2]

[0106] On average, the exemplary skateboard experienced 2.12 G less deceleration than the control skateboard. This reduction in deceleration for the exemplary skateboard translates to 66% less speed loss over the crack than the control skateboard.

[0107] As noted above, the speed retention experienced by the exemplary skateboard over bumps and wide joints provides a much smoother ride for users of multi-wheel truck skateboards when compared to skateboards with conventional trucks. Additionally, speed retention over obstacles allows users to travel the same distance with less energy when compared to conventional skateboards.

[0108] 3. Example 3 The deceleration over a one-inch bump at different approach angles for an exemplary skateboard of Example 1, equipped with a multi-wheel truck (six wheels total per truck) having a spring mechanism 130 according to the present invention and a level arm 110 with an angle of attack α of 43.72 degrees, was compared to a control skateboard equipped with a conventional truck lacking a level arm (two wheels total per truck). During each test, a user riding the skateboard approached the one-inch bump at a speed of 5.5 miles per hour. The deceleration experienced during impact with the bump for each test was measured with an accelerometer attached to the skateboard. Table 3 below shows the results of the comparison.

[0109] [Table 3]

[0110] For impacts occurring at a 90-degree (substantially vertical) approach angle, the exemplary skateboard experienced, on average, 1.40 G less deceleration than the control skateboard. This reduction in deceleration for the exemplary skateboard translates to 42% less velocity loss over bumps than the control skateboard. For impacts occurring at a 75-degree (15 degrees from vertical) approach angle, the exemplary skateboard experienced, on average, 0.69 G less deceleration than the control skateboard. This reduction in deceleration for the exemplary skateboard translates to 17% less momentum loss over bumps than the control skateboard. For impacts occurring at a 60-degree (30 degrees from vertical) approach angle, the exemplary skateboard experienced, on average, 0.58 G less deceleration than the control skateboard. This reduction in deceleration for the exemplary skateboard translates to 14% less momentum loss over bumps than the control skateboard. For impacts occurring at an approach angle of 45 degrees (45 degrees from vertical), the exemplary skateboard experienced, on average, 0.27 G less deceleration than the control skateboard. This reduction in deceleration for the exemplary skateboard translates to 8% less momentum loss than the control skateboard.

[0111] The greatest speed retention effect for the exemplary skateboard compared to the control skateboard occurred at impacts closest to the vertical approach angle. This is due to the suspension system directly providing a lifting effect on the bump. The exemplary skateboard experienced the least amount of deceleration when approaching the bump directly, while the control skateboard experienced a significant amount of deceleration when approaching the bump directly. A user of the exemplary skateboard can ride directly onto and successfully traverse an obstacle without significant loss of speed. This allows a user of the exemplary skateboard to take a more direct travel route and reduce travel time and distance during normal use of the skateboard.

[0112] The exemplary skateboard further demonstrated reduced deceleration for non-perpendicular angles. Even at shallow approach angles such as 45 degrees, which are not typical during skateboard use, the exemplary skateboard demonstrated significant retention of velocity compared to the control skateboard. It can be seen that the angle of attack α of the exemplary skateboard provides stability and allows the pull-up effect to occur even at extreme angles.

[0113] The replacement of one or more claimed elements is a reconstruction, not a repair. Additionally, benefits, other advantages, and solutions to problems have been described with respect to particular embodiments. However, the benefits, advantages, solutions to problems, and any one or more elements that cause or make more noticeable any benefit, advantage, or solution should not be construed as a critical, necessary, or essential feature or element of any or all of the claimed elements.

[0114] Furthermore, embodiments and limitations disclosed herein are not available to the public under the doctrine of public domain if the embodiment and / or limitation (1) is not explicitly claimed in the claims, and (2) is an equivalent or potential equivalent to the explicit elements and / or limitations in the claims under the doctrine of equivalents.

[0115] Various features and advantages of the disclosure are set forth in the following claims.

Claims

1. A truck, a hanger having a first end, a second end spaced from the first end, and a longitudinal axis extending from the first end to the second end; a wheel assembly located near one of the first end and the second end of the hanger and coupled to the hanger by a central axle; The wheel assembly includes: a center wheel and a level arm each coupled to the center axle, the center wheel and the level arm configured to rotate about the center axle and including a front opening, a middle opening, and a rear opening; a front axle received by the front opening of the level arm; a rear axle received by the rear opening of the level arm; a plurality of auxiliary wheels including a leading wheel attached to the front axle and a trailing wheel attached to the rear axle; an angle of attack defined between a first reference line tangent to a forward-most and outermost point of the leading wheel and a forward-most and outermost point of the center wheel, and a second reference line perpendicular to the longitudinal axis; track.

2. The truck of claim 1 , wherein the angle of attack is between 40 and 45 degrees.

3. The truck of claim 1 , wherein the angle of attack is between 42 degrees and 44 degrees.

4. 10. The truck of claim 1, wherein the lateral distance measured parallel to the longitudinal axis between the center wheel and the leading wheel is between about 1.5 inches and 2.0 inches.

5. 10. The truck of claim 1, wherein the front-to-rear distance between the front axle and the center axle is between about 1.5 inches and 2.0 inches.

6. 10. The truck of claim 1, wherein the front-to-rear distance between the center axle and the rear axle is between about 1.5 inches and 2.0 inches.

7. The truck of claim 1 , wherein the leading wheels have a diameter of approximately 2.5 inches to 3.0 inches.

8. the wheel assembly further comprising a spring mechanism configured to limit rotation of the level arm about the central axle; The truck of claim 1 , wherein the spring mechanism comprises a spring insert received within a recess in the level arm.

9. the spring insert comprises a body having a peripheral portion and a central portion; the spring insert further comprises at least one bent portion; The truck of claim 8 , wherein the bent portion extends from the periphery of the spring insert toward the central portion and is configured to bend outward toward the periphery.

10. The truck of claim 1 , wherein the center wheel is longitudinally spaced further from the hanger than the plurality of training wheels.

11. The truck of claim 1 , wherein the leading wheel and the trailing wheel are equidistant longitudinally from the hanger.

12. the central ring has a central ring width; each of the plurality of training wheels has a training wheel width; The truck of claim 11 , wherein the center wheel width is greater than the training wheel width.

13. the central hoop width is between about 1.5 inches and 1.75 inches; 13. The truck of claim 12, wherein the training wheel width is between about 0.5 inches and 0.7 inches.

14. A truck, a hanger, a pivot saddle, a base plate, and a plurality of wheels; The hanger is a first end and a second end spaced from the first end; a longitudinal axis extending between the first end and the second end; The track a first central axle coupled to the first end and a second central axle coupled to the second end; the first central axle and the second central axle extend along the longitudinal axis; The track a first center wheel coupled to the first center axle; a second center wheel coupled to the second center axle; an assembly; The assembly comprises: a first level arm coupled to the first central axle and a second level arm coupled to the second central axle; The first level arm is configured to connect a first leading wheel and a first following wheel, The second level arm is configured to connect a second leading wheel and a second following wheel, the first level arm is configured to rotate about the first central axle; the second level arm is configured to rotate about the second central axle; the track further comprises an angle of attack defined as the angle between a first reference line and a second reference line; the first reference line is tangent to the forward-most and outermost point of the first leading wheel and the forward-most and outermost point of the first central wheel, The second reference line is parallel to the longitudinal axis. track.

15. The truck of claim 14, wherein the angle of attack is between 40 and 45 degrees.

16. The truck of claim 14, wherein the angle of attack is between 42 and 44 degrees.

17. at least the first level arm includes a recess configured to receive a spring insert; The truck of claim 14 , wherein the spring insert comprises a spring shape configured to limit the rotation of the first level arm and the second level arm.

18. the first central ring and the second central ring have similar widths; the first leading wheel, the first following wheel, the second leading wheel, and the second following wheel have similar widths; 15. The truck of claim 14, wherein the width of the first center wheel and the second center wheel is greater than the width of the first leading wheel, the first trailing wheel, the second leading wheel, and the second trailing wheel.

19. the first leading wheel and the first following wheel are located on a first plane, the first plane is perpendicular to the longitudinal axis; the first center wheel is located on a second plane; The track of claim 14 , wherein the second plane is parallel to the first plane.

20. the first plane is longitudinally offset from the second plane by a distance of about 1.5 inches to 2.0 inches; 20. The track of claim 19, wherein the second plane is farther away from the first end of the hanger than the first plane.

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