Foldable wheels and how to make a foldable wheel

Abstract

Embodiments of foldable wheels and methods of making foldable wheels are generally described herein. Other embodiments may be described and claimed.

Description

[Technical Field]

[0001] This application is a continuation-in-part of U.S. Patent Application No. 16 / 934,995, filed July 21, 2020, and U.S. Provisional Application No. 62 / 951,509, filed December 20, 2019, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION This application relates generally to wheels, and more generally to foldable wheels and methods of making foldable wheels. [Background technology]

[0003] Some exercise equipment may require a wheeled vehicle for transportation. For example, a kayak may be transported on a kayak cart with wheels on a river or lake. The kayak cart may be detached from the kayak and stored on the kayak before launching the kayak onto the water. The kayak cart may have a foldable frame to reduce the size of the cart when not in use. In another example, a golfer may carry their golf bag over their shoulder in a golf pushcart or electric golf cart. A golf pushcart typically has a frame with two wheels attached to move the cart. The frame may also include a handle that a person holds to balance, pull, or push the cart, and a platform or base for the person's golf bag to rest on. The frame may be foldable to reduce the size of the pushcart when not in use for storage and / or transportation. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 is a perspective view of a wheel according to one embodiment shown in a deployed position.

[0005] [Figure 2] FIG. 2 is a perspective view of the wheel of FIG. 1 shown in a folded position.

[0006] [Figure 3] FIG. 2 is a perspective view of the wheel of FIG. 1 shown without a tire, according to one embodiment.

[0007] [Figure 4] FIG. 4 is a perspective view of the wheel of FIG. 3 shown in a folded position.

[0008] [Figure 5] FIG. 2 is a perspective view of two wheel sections of the wheel of FIG. 1.

[0009] [Figure 6] FIG. 2 is a partial front perspective view of the wheel of FIG. 1 shown in a deployed position.

[0010] [Figure 7] FIG. 1 illustrates a tire for use with a wheel according to one embodiment.

[0011] [Figure 8] FIG. 8 shows a portion of the tire of FIG. 7. [Figure 9] FIG. 8 shows a portion of the tire of FIG. 7.

[0012] [Figure 10] 8 illustrates the mounting of the tire of FIG. 7 on the wheel of FIG. 3 according to one embodiment. [Figure 11] 8 illustrates the mounting of the tire of FIG. 7 on the wheel of FIG. 3 according to one embodiment.

[0013] [Figure 12] FIG. 2 is a view showing a wheel portion of the wheel of FIG. 1;

[0014] [Figure 13] FIG. 2 shows an axle for the wheel of FIG. 1.

[0015] [Figure 14] 14 shows the axle of FIG. 13 mounted in the wheel of FIG. 1. FIG.

[0016] [Figure 15] FIG. 2 illustrates the wheel of FIG. 1 with an unfolding and folding mechanism, according to one embodiment. [Figure 16] FIG. 2 illustrates the wheel of FIG. 1 with an unfolding and folding mechanism, according to one embodiment. [Figure 17] FIG. 2 illustrates the wheel of FIG. 1 with an unfolding and folding mechanism, according to one embodiment. [Figure 18] FIG. 2 illustrates the wheel of FIG. 1 with an unfolding and folding mechanism, according to one embodiment.

[0017] [Figure 19] 10A-10C show a wheel according to another embodiment in the unfolded and folded positions, respectively. [Figure 20] 10A-10C show a wheel according to another embodiment in the unfolded and folded positions, respectively.

[0018] [Figure 21] FIG. 10 shows a wheel according to another embodiment in a folded position. [Figure 22] FIG. 10 shows a wheel according to another embodiment in a folded position.

[0019] [Figure 23] FIG. 23 shows the wheel of FIGS. 21 and 22 in a deployed position. [Figure 24] FIG. 23 shows the wheel of FIGS. 21 and 22 in a deployed position. [Figure 25] FIG. 23 shows the wheel of FIGS. 21 and 22 in a deployed position.

[0020] [Figure 26] FIG. 1 is a side view of a wheel according to one embodiment.

[0021] [Figure 27] FIG. 1 is a side view of a wheel according to one embodiment.

[0022] [Figure 28] 1A-1C are side views of a wheel according to one embodiment in an unfolded position and a folded position, respectively. [Figure 29] 1A-1C are side views of a wheel according to one embodiment in an unfolded position and a folded position, respectively.

[0023] [Figure 30] FIG. 1 is a side view of a wheel according to one embodiment. [Figure 31] FIG. 1 is a side view of a wheel according to one embodiment.

[0024] [Figure 32] FIG. 1 is a perspective view of a wheel according to one embodiment. [Figure 33] FIG. 1 is a perspective view of a wheel according to one embodiment.

[0025] [Figure 34] 1 is a partial perspective view of a wheel portion of a wheel according to one embodiment having a tire portion. FIG.

[0026] [Figure 35] FIG. 13 illustrates a wheel according to one embodiment in a deployed position. [Figure 36] FIG. 13 illustrates a wheel according to one embodiment in a deployed position.

[0027] [Figure 37] FIG. 36 shows the wheel of FIG. 35 in a folded position. [Figure 38] FIG. 13 illustrates a wheel according to one embodiment in a deployed position. [Figure 39] FIG. 36 shows the wheel of FIG. 35 in a folded position. [Figure 40] FIG. 36 shows the wheel of FIG. 35 in a folded position.

[0028] [Figure 41]FIG. 36 is a perspective cross-sectional view of a spoke of the wheel of FIG. 35.

[0029] [Figure 42] 1 is a flow diagram of a method of manufacturing a wheel according to one embodiment.

[0030] [Figure 43] 1A-1C illustrate a cart for carrying a golf club bag in deployed and stowed positions, each having wheels according to one embodiment. [Figure 44] 1A-1C illustrate a cart for carrying a golf club bag in deployed and stowed positions, each having wheels according to one embodiment.

[0031] [Figure 45] FIG. 10 is a perspective view of another embodiment of a wheel in a deployed position and having a track assembly.

[0032] [Figure 46] FIG. 46 is a perspective view of the wheel of FIG. 45 in a folded position.

[0033] [Figure 47] FIG. 47 is a side view of the wheel of FIGS. 45 and 46 comparing the folded position with the unfolded position.

[0034] [Figure 48] FIG. 46 is a side view of the wheel portion of the wheel of FIG. 45.

[0035] [Figure 49] FIG. 46 is a perspective view of the track portion of the wheel of FIG. 45 illustrating the outer surface.

[0036] [Figure 50] FIG. 50 is a perspective view of the track portion of FIG. 49 illustrating the inner surface.

[0037] [Figure 51]51 is an end view of the track section of FIG. 49 taken along line 51-51 of FIG. 49.

[0038] [Figure 52] 52 is a side view of the track section of FIG. 49 taken along line 52-52 of FIG. 51.

[0039] [Figure 53] FIG. 46 is a perspective view of a portion of the track assembly of FIG. 45 illustrating the outer surface.

[0040] [Figure 54] FIG. 54 is a perspective view of a portion of the track assembly of FIG. 53 illustrating the inner surface.

[0041] [Figure 55] 54 is a perspective view of a wheel portion of the wheel of FIG. 45 configured to be secured to a portion of the track assembly of FIG. 53.

[0042] [Figure 56] FIG. 46 is a perspective view of the wheel of FIG. 45 illustrating a spacer positioned between adjacent wheel portions.

[0043] [Figure 57] FIG. 10 is a perspective view of another embodiment of a wheel in a deployed position and having a track assembly.

[0044] [Figure 58] 58 is a perspective view of a portion of the wheel track assembly of FIG. 57 taken along line 58-58 of FIG. 57.

[0045] [Figure 59] FIG. 58 is a perspective view of the wheel of FIG. 57 with a portion of the track assembly removed to further illustrate the wheel section in a deployed position, and a portion of the track assembly secured to the wheel section.

[0046] [Figure 60]FIG. 58 is a perspective view of the wheel of FIG. 57 with a portion of the hub assembly removed to illustrate only a single wheel section.

[0047] [Figure 61] 61 is a perspective view of the wheel of FIG. 60 illustrating an opposite side to that of FIG. 60.

[0048] [Figure 62] 58 shows a perspective view of an alternative track section for use with the wheel track assembly of FIG. 57 illustrating the outer surface.

[0049] [Figure 63] FIG. 63 is a perspective view of the track portion of FIG. 62 illustrating the inner surface.

[0050] [Figure 64] FIG. 10 is a perspective view of a wheel according to another embodiment shown in a deployed position.

[0051] [Figure 65] FIG. 65 is a perspective view of the wheel of FIG. 64 shown in a folded position.

[0052] [Figure 66] FIG. 65 is a side view of the wheel of FIG. 64 shown in the deployed position.

[0053] [Figure 67] FIG. 65 is a side view of the wheel of FIG. 64 shown in a folded position.

[0054] [Figure 68] FIG. 65 is an enlarged view of a portion of the adjacent rim of the wheel of FIG. 64.

[0055] [Figure 69] FIG. 10 is a side view of a portion of a wheel according to another embodiment showing an internal view of the central hub portion in a folded configuration.

[0056] [Figure 70]FIG. 70 is a side view of a portion of the wheel of FIG. 69 showing an internal view of the central hub portion in an unfolded configuration.

[0057] [Figure 71] 10 shows an example of a wheel according to another embodiment with a locking system. FIG.

[0058] [Figure 72] 10 shows an example of a wheel according to another embodiment with a locking system. FIG.

[0059] [Figure 73] FIG. 10 is a perspective view of a wheel according to another embodiment shown in a deployed position.

[0060] [Figure 74] FIG. 74 is a perspective view of the wheel of FIG. 73 shown in a folded position.

[0061] [Figure 75] FIG. 74 is a side view of the wheel of FIG. 73 shown in the deployed position.

[0062] [Figure 76] FIG. 74 is a side view of the wheel of FIG. 73 shown in a folded position.

[0063] [Figure 77] FIG. 74 is an enlarged view of a portion of the adjacent rim of the wheel of FIG. 73.

[0064] [Figure 78] FIG. 10 is a perspective view of a wheel according to another embodiment shown in a deployed position.

[0065] [Figure 79] FIG. 79 is a perspective view of the wheel of FIG. 78 shown in a folded position.

[0066] [Figure 80] FIG. 79 is a side view of the wheel of FIG. 78 shown in the deployed position. DETAILED DESCRIPTION OF THE INVENTION

[0067] 1 and 2, a wheel 100 is shown in accordance with one example of the apparatus, methods, and articles of manufacture described herein. Wheel 100 includes a hub assembly 102 and a tire 104, at least a portion of which is mounted around hub assembly 102 for contacting the ground. Wheel 100 also includes an axle 106 on which hub assembly 102 is rotatably mounted. One or more wheels 100 may be used on a cart or vehicle for transporting any object.

[0068] FIG. 1 shows the wheels 100 in an unfolded position. To reduce the size of the wheels 100 for transportation and / or storage, one may fold the wheels 100 into the folded position shown in FIG. 2. For example, the trunk of a car may not have enough space to accommodate a golf club cart when the cart's wheels 100 are in the unfolded position. By placing the wheels 100 in the folded position, the cart and wheels 100 can fit inside the cart's trunk for transportation. Thus, folding the wheels from the unfolded position to the folded position allows the wheels and / or any object to which they are attached to occupy less space. As discussed in more detail below, each wheel 100 may be removable from the cart to further reduce the space that may be occupied by the cart and wheels 100.

[0069] 3-6, the hub assembly 102 is shown in an unfolded position and a folded position, respectively. The hub assembly 102 includes a plurality of stacked wheel sections 110. Each wheel section 110 includes a hub section 112 with a central bore 114. The wheel sections 110 may be concentrically stacked such that the central bores 114 are axially aligned to form an elongated bore for receiving the axle 106. Each wheel section 110 may include at least one spoke 116 and a rim 118. In the example of FIGS. 1-5, each wheel section 110 has a first pair of spokes 116 projecting radially from the hub section 112 for connection to a first rim 118, and further has a second pair of spokes 116 projecting radially from the hub section 112 opposite the first pair of spokes 116 for connection to a second rim 118. Each rim 118 receives and supports a portion of the tire 104. Each wheel portion 110 may include any number of spokes 116 extending from the hub portion 112 to one or more rims 118. For example, each rim 118 may be coupled to only one spoke 116 or to multiple spokes 116. The spokes 116 may have any shape. For example, each spoke 116 may be straight, bent at one or more locations along its length, and / or have curvatures. In the example of FIGS. 1-5 , the spokes 116 may be curved to function as springs when the wheel 100 is in use. Thus, when a force is applied on the rim 118 during operation of the wheel 100, the curved shape of each spoke 116 promotes elastic bending of the spoke 116 so that the spoke 116 provides a shock-absorbing function.

[0070] Each wheel section 110 may be freely rotatable about the axle 106 such that the wheel section 110 can be deployed from the folded position shown in FIG. 4 to the deployed position shown in FIG. 3. The number of wheel sections 110, the thickness of each wheel section 110, and / or the radial span of each wheel section 110 may be determined so that in the deployed position of the wheel 100, a true circular wheel is formed, i.e., approximately 360 degrees are defined by the wheel 100, and the rim 118 provides sufficient support to the tire 104 for proper operation of the wheel 100. Providing sufficient support to the tire 104 at any point during operation of the wheel 100 may be defined by the number of contact points between the wheel 100 and the ground. Each rim 118 may be defined as having one contact point, and although referred to herein as a contact point, a contact point may refer to the area of ​​the rim 118 that contacts the ground. Increasing the number of contact points between the wheel 100 and the ground increases the stability of the wheel 100 and therefore the stability of the vehicle, i.e., the push cart, to which the wheel 100 is attached.

[0071] The radial span of each wheel unit 110 may determine the radial position of each wheel unit 110 relative to adjacent wheel units 110 in the deployed position of the wheel 100, and the number of wheel units 110 that may be required. As shown in FIG. 5 and as used herein, the radial span 119 may generally define the length of the rim 118 that contacts the ground during operation of the wheel 100. For example, if each rim 118 of a pair of rims 118 of a wheel unit 110 defines a radial span of approximately 90 degrees, only two wheel units 110 may be required such that the rims 118 define a perfect circle, or approximately 360 degrees, with generally no overlap or gap between two adjacent rims 118, or each rim 118 may define a radial span of 90 degrees on the perfect circle that generally defines the wheel 100. In other words, each wheel unit 110 may define a radial span of 180 degrees on the perfect circle that generally defines the wheel. In another example, if each rim 118 of a pair of rims 118 of a wheel assembly 110 has a radial span 119 of approximately 45 degrees, four wheel assembly 110, or eight rims 118, may be required so that the rims 118 define a perfect circle or approximately 360 degrees, generally without any overlap or gap between two adjacent rims 118. The general configuration of wheel 100 may therefore be defined by the following exemplary equation:

number

[0072] where W represents the number of wheel sections, N represents the number of opposing rims 118 on each wheel (e.g., N is 2 in the example of Figures 2-5), C represents the number of ground contact points, and R represents the radial spacing (in degrees) of each wheel section relative to adjacent wheel sections.

[0073] As discussed above, increasing the number of contact points between the wheel 100 and the ground may increase the stability of the wheel 100. Each rim 118 may contact the ground at one contact point. By providing multiple contact points, i.e., multiple rims 118, that are in contact with the ground at any one time, the stability of the wheel 100 may be increased. In other words, increasing the number of contact points with the ground at any one time during operation of the wheel 100 increases the width of the wheel 100, thereby increasing the number of wheel sections 110 that can be used to form the wheel 100.

[0074] Referring to FIG. 5 , an example of a wheel 100 is shown where each wheel section has a rim 118 with a radial span 119 of approximately 45 degrees. Thus, adjacent wheel sections 110 may generally be radially spaced apart by approximately 45 degrees in the deployed position of the wheel 100, as shown in FIG. 5 . In the example of FIG. 5 , four wheel sections 110, i.e., eight rims 118, would be required to define a perfect circle, or approximately 360 degrees. Thus, if the wheel 100 were constructed with four wheel sections 110, only one rim 118, i.e., one contact point, would contact the ground at any one time. To increase the stability of the wheel 100, sixteen wheel sections 110 may be provided as shown in the example of FIG. 4 , such that four contact points on the wheel 100 contact the ground at any one time during operation of the wheel 100, i.e., four rims 118 define the width of the wheel 100. Any number of wheel sections 110 may be provided to increase or decrease the number of contact points. For example, 20 wheel units 110 would provide five contact points with the ground for the wheel 100 at any one time. In another example, 12 wheel units 110 would provide three contact points with the ground. In accordance with the above, at least eight rims 118 may be required so that when each rim 118 spans approximately 45 degrees, one contact point contacts the ground at any one time during the operation of the wheel 100. When each rim 118 has a radial span 119 of approximately 45 degrees, a plurality of four wheel units 110 may be provided to increase the number of contact points along the width of the wheel. In the example of FIG. 4, 16 wheel units 110 for the wheel 100 would provide four contact points at any one time during the operation of the wheel, as shown in FIG. 6.

[0075] Increasing the number of wheel units 110 may increase the stability of the wheels 100 and / or the weight that the wheels 100 can support. However, increasing the number of wheel units 110 may also increase the size and / or weight of the wheels 100 in the folded position. Thus, the size of each wheel unit 110, and other characteristics of each wheel unit 110 as described herein, may be determined depending on the size and load of the cart to which one or more wheels 100 may be attached.

[0076] FIG. 6 shows two wheel assemblies 110 in a deployed position. The rim 118 of each wheel assembly 110 includes a radial projection 120. Referring to FIGS. 7-11, the tire 104 may include an inner surface 130 and an outer surface 132. The outer surface 132 may be smooth or may have a tread. The inner surface 130 may have any configuration that provides for mounting of the tire 104 on the rim 118. In the example of FIGS. 8 and 9, the inner surface 130 includes a plurality of generally parallel ribs 134 that define a plurality of generally parallel grooves 136 between the ribs 134. The ribs 134 and grooves 136 may extend radially across a portion of the inner surface 130. In the example of FIGS. 8 and 9, the ribs 134 and grooves 136 extend across the entire 360 ​​degrees of the inner surface 130 of the tire 104.

[0077] 10 and 11 , the distance between adjacent grooves 136 generally corresponds to the distance between adjacent protrusions 120 of the wheel section 110. Additionally, the cross-sectional shape of each groove 136 may generally correspond to the cross-sectional shape of the protrusions 120. Thus, when the tire 104 is mounted on the wheel section 110, the protrusions 120 may engage the grooves 136 and generally fit within the grooves 136. The protrusions 120 and grooves 136 may have any cross-sectional shape. In the example of FIG. 11 , the protrusions 120 are shown as having a generally triangular cross-sectional shape, and the grooves 136 are also shown as having a generally corresponding triangular cross-sectional shape. Furthermore, the size of the grooves 136 may generally correspond to the size of the protrusions 120. For tires 104 constructed from a resilient material, such as rubber, the grooves 136 may alternatively be formed smaller than the protrusions 120 such that the grooves 136 resiliently expand to provide a generally mating engagement with the protrusions 120 upon receiving them. The tire may be mounted to one or more rims 118 such that the tire remains in a mounted configuration on the wheel 100 in both the folded and unfolded positions of the wheel 100.

[0078] As discussed above, each wheel section 110 may be positioned at a particular angle relative to adjacent wheel sections 110 during operation of the wheel 100 to provide a sufficient number of contact points and generally evenly distributed contact point locations on the wheel 100. For example, the wheel sections 110 in FIG. 5 are positioned at approximately 45 degrees relative to each other in the deployed position to provide four evenly distributed contact points at any time during operation of the wheel 100. The angle between wheel sections 110 in the deployed position that provides a sufficient number of contact points and a generally even distribution of contact point locations on the wheel may be referred to herein as the deployment angle. The deployment angle is shown in equation (1) as the variable R. Thus, the deployment angle for the example of FIG. 5 is approximately 45 degrees.

[0079] As detailed above and explained with respect to equation (1), the deployment angle may vary depending on the configuration and / or characteristics of the wheel section 110. To limit the deployment of the wheel sections 110 relative to one another and / or provide for positioning of the wheel sections 110 at deployment angles relative to one another, the wheel 100 may include a deployment angle limiting mechanism whereby rotation of each wheel section 110 relative to adjacent wheel sections 110 is limited to the deployment angle. According to one example shown in FIG. 12 , the angle limiting mechanism includes a radial slot 140 on the hub section 112 of each wheel section 110 and a pin 144 that may be positioned on the hub section 112 opposite the slot 142 relative to the central bore 114. The arc length of each radial slot 140 may generally be less than or equal to the deployment angle. In the example of FIG. 12 , the arc length of the radial slot 140 is approximately 45 degrees, which is the same as the deployment angle. When the wheel units 110 are assembled, i.e., stacked on top of each other, as described in detail below, the pins 144 of each wheel unit 110 rest within the slots 140 of the adjacent wheel unit 110. Thus, when adjacent wheel units are rotated relative to each other, the pins 144 move within the slots 140. However, the radial movement of the pins 144 is limited by the arc length of the slots 140, which defines the radial movement of the wheel unit 110 with the pins 144.

[0080] Each slot 140 includes a first end 150 and a second end 152. In the folded position of the wheel 100, the pin 144 of each wheel section 110 is disposed near the first end 150 of the slot 140 of the adjacent wheel section 110. As the wheel 100 is unfolded, the pin 144 moves within the slot 140 from the first end 150 until the pin 144 contacts the second end 152 of the slot 140. The slot 140 thus limits the rotation of the two adjacent wheel sections 110 relative to each other to the unfolding angle or radial arc length of the slot 140. The position of each slot 140 and pin 144 may be determined so that the wheel 100 can be unfolded and folded as disclosed. In the example of FIG. 12, the first end 150 of the slot 140 is disposed generally along the central longitudinal axis 154 of the hub section 112. Thus, the second end 152 of the slot 140 is disposed approximately 45 degrees from the first end 150. The pin 144 is also disposed on the central longitudinal axis 154 but on the opposite side of the central bore 114 from the first end 150 of the slot 140. As will be described in more detail below, the arrangement of the pin 144 and slot 140 provides for each wheel unit 110 to be rotated relative to the adjacent wheel unit through a deployment angle, as shown in FIG.

[0081] After the wheels 100 are deployed, which is defined by each wheel section 110 having a deployment angle relative to adjacent wheel sections 110, the wheels 100 may be maintained in the deployed position by any type of latching, locking, and / or similar mechanism that prevents the wheel sections 110 from rotating relative to one another. For example, each wheel section 110 may include an opening (not shown) positioned on the hub section 112 such that when the wheel sections 110 are in the deployed position of the wheel 100, all openings in the wheel sections 110 are generally aligned to receive a rod (not shown). The rod thus prevents the wheel sections 110 from rotating relative to one another. In another example, a U-shaped bracket (not shown) having a width generally similar to the overall width of the hub sections 112 may be placed over the hub sections 112 to prevent the hub sections 112 from rotating relative to one another.

[0082] 13 and 14 , the wheel units 110 may be rotatably mounted on axles 106. The axles 106 may be defined by a cylindrical axle 160 having a first end 162 and a second end 164. In the example of FIGS. 13 and 14 , the axles 106 may further include a mounting bracket 166 having a first bracket portion 168 and a second bracket portion 170. The mounting bracket 166 may facilitate mounting or attaching the wheels 100 to a cart, such as a golf stroller. The wheel units 110 may be mounted on the axles 160 by inserting the axles 160 from the first end 162 into the central bore 114 of each wheel unit 110. The axles 106 may include a mechanism by which the first wheel unit 110 mounted on the axles 160 is held stationary, thereby allowing the wheels 100 to be deployed from a folded position. 13 , the first bracket portion 160 includes a pin hole 170 for receiving the pin 144 of the first mounted wheel portion 110. The engagement of the pin 144 with the pin hole 170 of the first mounted wheel portion 110 maintains the first mounted wheel portion 110 secured to the first bracket portion 160 such that the wheel 100 can be deployed from a folded position to an deployed position. After the wheel 100 is deployed, the pin 144 may be removed from the pin hole 170 to allow the wheel 100 to rotate about the axis 160.

[0083] The axle 106 may further include a wheel retention mechanism by which the wheel 100 is maintained on the axle 160 during operation of the wheel 100. The wheel retention mechanism may include any configuration that prevents the wheel 100 from sliding off or being removed from the axle 106 during operation of the wheel 100. For example, the first end 162 of the axle 160 may be threaded to receive a correspondingly threaded nut (an example is shown in FIG. 22 ). The threaded nut increases the diameter of the axle 160 at the first end 162 to a diameter greater than the central bore 114 of the hub portion 112. The wheel portion 110 is thus stopped by the nut when it reaches the first end 162 of the axle 160.

[0084] In the example of FIG. 13 , the axle 160 includes an annular recess 172 at or near the first end 162 of the axle 160. As shown in FIG. 14 , after the wheel unit 110 is installed on the axle 160, a spring clip 174 may be installed over the axle 160 and pressed onto the axle 160 so that the spring clip 174 snaps into and remains within the annular recess 172. The spring clip 174 increases the diameter of the axle 160 at the first end 162 to a diameter greater than the diameter of the central bore 114 of the hub portion 112. Thus, the wheel unit 110 is stopped by the spring clip 174 when it reaches the first end 162 of the axle 160. The axle 106 may also include a washer 176 or the like installed between the spring clip 174 and the last installed wheel unit 110. To provide for easy installation of the spring clip 174 into the annular recess 174, the first end 162 of the axle may be tapered, as shown in Figures 13 and 14, such that pressing the spring clip 174 onto the first end 162 causes the spring clip 172 to gradually deploy on the axle 160 as it is installed thereon. Thus, the spring clip 174 remains engaged in the annular recess 172 until it deploys, regardless of whether or not a person has a tool to remove the spring clip 174 from the axle 160, thereby allowing the wheel portion to be removed from the axle 160. At the second end 164 of the axle 160, an annular shoulder 178 may be provided to space the first installed wheel portion 110 from the first bracket portion 168.

[0085] FIG. 2 shows the wheel 100 in a folded position with a tire 104 mounted thereon. The tire 104 may be constructed from a resilient material, such as rubber. Furthermore, the inner diameter of the tire 104 may be smaller than the outer diameter of the circle defined by the wheel 100 in the unfolded position. Thus, the tire may be easily mounted onto the wheel 100 in the folded position. However, when the wheel 100 is unfolded, the tire 104 may unfold elastically. The elastic unfolding of the tire 104 may create a restoring force within the tire 104, whereby the tire 104 is pressed onto the rim 118 (e.g., the protrusions 120 are pressed into the grooves 136) and maintains the tire 104 on the wheel 100 during operation of the wheel 100.

[0086] To deploy the wheel 100 from the folded position to the unfolded position, each wheel unit 110 may be rotated by hand. In one example shown in FIGS. 15 and 16 , the wheel 100 includes a hub cap 200 by which the wheel units 110 may be rotated relative to one another to unfold the wheel 100. The hub cap 200 may include two opposing handles 202 and 204 that can be held by a person to rotate the hub cap 200. The hub cap 200 may include a pin (not shown) on its inner surface, which may engage within the slot 140 of the last attached wheel unit 110. The hub cap 200 may be rotatably mounted on the axle 106. Thus, when the hub cap 200 is rotated about the axle 106 by a person, the pin on the inner surface of the hub cap 200 moves within the slot 140 of the first wheel unit 110 until the pin engages the second end 152 of the slot 140. After the first wheel unit 110 has been rotated through the deployment angle, the pin 144 of the first wheel unit 110 engages the second end 152 in the slot 140 of the second wheel unit 110 as described above. Further rotation of the hubcap 200 therefore rotates the second wheel unit 110 through the deployment angle relative to the third wheel unit 110. Continued rotation of the hubcap 200 rotates the remaining wheel units 110 until the wheel 100 is fully deployed. The hubcap 200 may be mounted on the axle 160 between the last mounted wheel unit 110 and the spring clip 174. While holding the handles 202 and 204, a person can also hold the second bracket unit 166 to provide leverage when deploying the wheel 100.

[0087] 17 and 18 show another example wheel 400. The wheel 400 is similar to the wheel 100 in certain aspects. Accordingly, similar portions of the wheel 100 and the wheel 400 are designated with the same reference numerals. The wheel 400 includes a plurality of wheel sections 110 mounted on an axle 406 (shown in FIG. 17). The axle 406 includes a first end 462 (shown in FIG. 17) and a second end (not shown). The axle 406 receives the wheel sections 110 by being inserted into the central bores 114 of the wheel sections 110. The second end of the axle 406 includes a base 470 having a diameter larger than the diameter of the central bores 114 of the wheel sections 110. Accordingly, when the wheel sections 110 are mounted on the axle 406, the wheel sections 110 are secured at the second end of the axle by the base 470. To prevent the wheel section 110 from being removed from the axle 406 during operation of the wheel 400, the second end 462 of the axle 406 may be threaded to receive a correspondingly threaded nut 480. Tightening the nut 480 on the threaded first end 462 of the axle 406 thus prevents the wheel section 110 from being removed from the axle 406 during operation of the wheel 400. Alternatively, the axle 400 may include a wheel retention mechanism similar to the wheel retention mechanism of the wheel 100, as described in detail above. The wheel 400 includes a hub cap 200 that may be used to deploy the wheel 400 from a folded position to an unfolded position, as described in detail above with respect to the wheel 100.

[0088] 18 , the first attached wheel unit 110 may include two opposing handles 502 and 504 on the central hub portion 112 positioned similarly to the handles 202 and 204 of the hubcap 200. Thus, a person can unfold the wheel 400 from the folded position by holding the handles 202 and 204 with one hand and rotating them in one direction, and holding the handles 502 and 504 with the other hand and rotating them in the opposite direction to rotate the wheel units relative to each other and deploy the wheel 400 to the unfolded position. The handles 502 and 504 may be part of a hubcap (not shown) that is mounted onto the axle 406 before the first attached wheel unit 110 is mounted thereon. Alternatively, as shown in FIGS. 17 and 18 , the handles 502 and 504 may be integral parts of the first attached wheel unit 110.

[0089] 19 and 20, a wheel 600 according to another embodiment is shown. The wheel 600 is similar in some aspects to the wheels 100 and 400. Accordingly, similar parts of the wheels 100, 400, and 600 are designated with the same reference numerals. The wheel 600 includes a plurality of wheel sections 610. Each wheel section 610 includes a hub section 612 with a central hole (not shown). Each wheel section 610 includes a pair of spaced-apart, generally straight spokes 616 on each side of the outer periphery of the hub section 612 that project radially outward and connect to a generally curved rim 618. The distance between each pair of spokes 616 may increase from the hub section 612 to the rim 618. Thus, each pair of spokes 616 and the corresponding rim 618 define a generally trapezoidal shape. The wheel 600 includes an axle 606 that is mounted through the central hole of the wheel section 610. Axle 606 and the mechanisms and manner by which axle 606 is operably connected to the wheels and cart are similar to axles 106 and 406. Accordingly, a detailed description of axle 606 is not provided.

[0090] 21-25, another example wheel 800 is shown. Wheel 800 includes a hub assembly 802 and a tire (not shown) mounted on hub assembly 802 as described below. Wheel 800 also includes an axle 806 on which hub assembly 802 and tire are rotatably mounted. Hub assembly 802 includes multiple wheel sections 810 coaxially mounted on axle 806. Each wheel section 810 includes a hub section 812 having a central bore 814 for receiving a portion of axle 806.

[0091] The tire may be mounted on a number of rims 818 positioned along the periphery of a circle 817 that defines the center plane of the wheel 800. Each rim 818 is oriented generally perpendicular to the circle 817 (shown in FIG. 24) and is convex relative to the hub portion 812. Each rim 818 is therefore concave relative to the tire to receive the curvature of the tire (not shown). Each rim 818 is attached to two spaced-apart hub portions 812 by two spokes 816 each. The two hub portions 812 to which the rims 818 are attached by the spokes 816 are spaced apart so that the spokes 816 form a V-shaped support for each rim 818. For example, as shown in FIG. 22, the spokes 816 supporting the rims 818 connected to the hub portions 812 are spaced apart by five hub portions 812. Each hub portion 812 therefore has one spoke 816 on one side thereof that partially supports a first corresponding rim 818, and another spoke 816 on its opposite side that partially supports a second corresponding rim 818.

[0092] 23-25 ​​show the unfolded position of wheel 800. The spokes 816 are positioned on hub portion 812 so that when wheel 800 is in the unfolded position, the spokes 816 are evenly distributed around the wheel, i.e., radially spaced at similar unfolded angles on circle 817. In the example of FIGS. 23-25, the spokes 816 are shown spaced approximately 30 degrees apart in the unfolded position of wheel 800. FIGS. 21 and 22 show the folded position of wheel 800. To fold wheel 800, hub portions 812 may be rotated relative to one another until rims 818 contact one another and prevent further rotation of hub portions 812. To unfold wheel 800, hub portions 812 may be rotated in opposite directions relative to one another so that wheel 800 reaches the unfolded position shown in FIG. 23. Because each spoke 816 is located on a different hub portion 812, wheel 800 may require less than 180 degree rotation to deploy from the folded position to the unfolded position. Thus, to deploy wheel 800 from the folded position shown in FIG. 21 , spoke 820 is rotated clockwise until spoke 820 is positioned adjacent to spoke 822 and is prevented from further rotation by a deployment limiting mechanism, as described below. Simultaneously, spoke 824 is rotated clockwise until spoke 824 is positioned adjacent to spoke 826 and is prevented from further rotation by a deployment limiting mechanism. Thus, the maximum rotation of hub portion 812 may be less than 180 degrees to deploy the wheel from the folded position to the unfolded position.

[0093] To prevent further rotation of the hub portions 812 relative to one another when the wheels 800 reach the deployed position shown in FIG. 23 , the wheels 800 may include a deployment limiting mechanism, as described above. Thus, each wheel portion 810 may include a radial slot (not shown) on the hub portion 812 and a pin (not shown) on the hub portion 812, which may be located on the opposite side of the hub portion 812 from the slot relative to the central hole 814. The arc length of each radial slot 140 may generally be less than or equal to the deployment angle. In the example of FIG. 24 , the arc length of the radial slot is approximately 30 degrees, which is the same as the deployment angle.

[0094] A tire (not shown) may be mounted on wheel 800 before or after the wheel is unfolded. The tire may be constructed from a solid piece of rubber or other type of plastic material that has sufficient elasticity to allow the tire to be mounted on wheel 800. Alternatively, the tire may be in the form of an inflatable tube that may be mounted on rim 818. Thus, the tire may be inflated by a person prior to operating wheel 810. Further alternatively, the tire may be attached to one or more rims 818 such that the tire is maintained in its mounted configuration on wheel 800 in both the folded and unfolded positions of wheel 800.

[0095] 26-33 illustrate several exemplary wheels and / or wheel units according to the present disclosure. As shown in FIG. 26, the wheel unit 1010 may include at least one spoke 1016 on each side of the hub portion 1012. The wheel unit 1010 also includes at least one rim 1018 attached to each spoke 1016. Each spoke 1016 and corresponding rim 1018 generally define a T-shaped spoke and rim assembly. As shown in FIG. 27, the wheel unit 1110 may include at least one spoke 1116 on each side of the hub portion 1112. The wheel unit 1110 also includes at least one rim 1118 attached to each spoke 1116. Each spoke 1116 and corresponding rim 1118 generally define an L-shaped spoke and rim assembly. According to the exemplary wheel units 1010 and 1110, the at least one rim and at least one spoke may be attached to each other in any configuration. For example, the ends of the spokes may be attached to the center of the length of the rim, as shown by wheel portion 1010, to provide a generally T-shaped spoke and rim assembly. However, in example wheel portion 1110, the ends of the spokes are attached to one end of the rim. Thus, the spokes and rim may be attached to each other in any configuration and with any type of offset relative to each other.

[0096] 28 and 29 show another example wheel 1200. The wheel 1200 includes multiple wheel sections 1210, where each wheel section 1210 may have a different configuration compared to one or more other wheel sections 1210. For example, each wheel section 1210 may have spokes 1216 of a different shape. The spokes 1216 may be straight, curved, L-shaped, Z-shaped, and / or have any other shape that may be different from the spokes 1216 of one or more other wheel sections 1210. Depending on the shape of each spoke 1216, each spoke may have a different thickness, may be constructed from a different material, and / or may have certain characteristics that may be different from or similar to one or more other spokes 1216 of one or more other wheel sections 1210. The tire 1204 may be mounted on the wheel 1200 in both the folded and unfolded positions of the wheel 1200.

[0097] FIGS. 30 and 31 show another example wheel 1300. The wheel 1300 includes a plurality of spokes 1316. Each spoke may be flexible to deform from an unfolded position corresponding to the unfolded position of the wheel 1300 to a deformed position corresponding to the folded position of the wheel 1300. FIG. 30 shows an example of a wheel 1300 in the process of unfolding between a folded position and the unfolded position shown in FIG. 31. In the unfolded position of the spokes 1316 as shown in FIG. 31, the spokes 1316 have sufficient overall stiffness to support loads on the tire 1304 and hub assembly 1302 to provide operation of the wheel 1300 as disclosed. However, the spokes 1316 are flexible such that the wheel 1300 can be folded by deforming the spokes 1316 to fold the wheel 1300. As shown in the example of FIG. 30, the spokes 1316 may be deformed by bending and stacked on top of each other around the hub 1312. The spokes 1316 may also provide shock absorption functionality for the wheel 1300. The wheel 1300 may include a single hub 1312 to which all of the flexible spokes 1316 are attached. Alternatively, the wheel 1300 may include multiple hub sections, where each hub section is rotatable relative to adjacent hub sections to facilitate folding and unfolding of the wheel 1300, to which one or more spokes 1316 may be attached. As shown in Figures 30 and 31, the wheel 1300 may also include a tire 1304, which may be similar to the example tires disclosed herein.

[0098] 32 and 33 show another example wheel 1400. The wheel 1400 includes a hub 1412 to which a rim 1418 is attached. The rim 1418 includes a first rim portion 1420 and a second rim portion 1422 that are pivotally attached to the hub 1412 by one or more hinges 1424. As shown in FIG. 33, the first rim portion 1420 and the second rim portion 1422 can be pivoted at the hinges 1424 to fold the wheel 1400 from the unfolded position shown in FIG. 32 to a folded position (not shown). Thus, the size of the wheel 1400 may be reduced for storage and / or transportation when the wheel is folded from the unfolded position.

[0099] Referring to FIG. 34 , a portion of another example wheel 1500 is shown. The wheel 1500 includes at least one spoke 1516 and at least one rim 1518 attached to the spoke 1516. The wheel 1500 need not include an integral tire similar to the examples described above. Instead, a tire portion 1504 is attached to each rim 1518. Thus, when the wheel 1500 is deployed in its deployed position, the tire portions 1504 collectively define a tire for the wheel 1500. The tire for the wheel 1500 is thus defined by the plurality of tire portions 1504 and any gaps that may exist between adjacent tire portions 1504. As with the examples described above, the tire portions 1504 may be constructed from a resilient material such as rubber. The tire portions 1504 may then be attached to the rim 1518 with adhesive, one or more fasteners, and / or one or more other types of attachment devices or procedures.

[0100] 35-41 , another example wheel 1600 is shown. The wheel 1600 includes a hub assembly 1602. The wheel 1600 may include a tire (not shown) that may be mounted on the hub assembly 1602. Alternatively, the wheel 1600 may include multiple tire sections, as described above with respect to the wheel 1500. Alternatively, the wheel 1600 may operate without a tire. The wheel 1600 also includes an axle 1606 on which the hub assembly 1602 is rotatably mounted. The hub assembly 1602 includes multiple wheel sections 1610 that are concentrically mounted on the axle 1606. Each wheel section 1610 includes a hub section 1612 having a central bore 1614 for receiving a portion of the axle 1606.

[0101] The wheel 1600 includes a plurality of rims 1618 configured to define a path on a circumferential or circular band 1617 having a width 1619. The path defined by the rims 1618 may be substantially continuous. The circular band 1617 defines a circular contact area between the wheel 1600 and the ground, similar to a tire (shown in FIG. 38 ). In the deployed position of the wheel 1600, each rim 1618 may be oriented such that at least one point on at least one rim 1618 contacts the ground. In one example, each rim 1618 is positioned diagonally on the circular band 1617. Each rim 1618 may be radially spaced from an adjacent rim 1618, so long as the space does not provide a clearance large enough to substantially prevent or impede the wheel 1600 from rolling generally smoothly over the ground. Alternatively, each rim 1618 may have no radial clearance from an adjacent rim 1618. Alternatively, each rim 1618 may have a radial overlap with an adjacent rim 1618. In the example of FIG. 38, each rim 1618 has a small gap relative to the adjacent rim 1618. Also, each rim 1618 may be curved such that points on adjacent rims 1618 spaced apart by a particular angle lie on the circular band 1617. Thus, as shown in FIG. 35, the rims 1618 define a portion of a generally continuous circular path in the deployed position of the wheel 1600. In other words, the curvature of each rim 1618 may generally follow a curvature relative to a circle that defines the plane of the wheel 1600.

[0102] Each rim 1618 is attached to two spaced apart hub portions 1612 by two spokes 1616 each. The two hub portions 1612 to which the rims 1618 are attached by the spokes 1616 are spaced apart so that the spokes 1616 form a V-shaped support for each rim 1618. For example, as shown in FIG. 41 , the spokes 1616 supporting the rims 1618 are spaced apart by four hub portions 1612. Each hub portion 1612 therefore has one spoke 1616 on one side thereof that partially supports a first corresponding rim 1618, and another spoke 1616 on its opposite side that partially supports a second corresponding rim 1618.

[0103] FIGS. 35, 36, and 38 show the unfolded position of the wheel 1600. The spokes 1616 are positioned on the hub portion 1612 so that when the wheel 1600 is in the unfolded position, the spokes 1616 are evenly distributed around the wheel, i.e., equally spaced radially at similar deployment angles. In the example of FIG. 35, the spokes 1616 are shown spaced approximately 30 degrees apart in the unfolded position of the wheel 1600. FIGS. 37, 39, and 40 show the folded position of the wheel 1600. To fold the wheel 1600, the hub portions 1612 may be rotated relative to one another until the rims 1618 contact each other and prevent further rotation of the hub portions 1612. Each spoke 1616 may have a particular cross-sectional shape to provide a more compact folded position for the wheel 1600. For example, each spoke 1616 may have a diamond-shaped cross-section, as shown in FIG. 41. Thus, when the wheel 1600 is folded, each spoke 1616 may be positioned in a complimentary or matching manner relative to adjacent spokes 1616. Thus, the spokes 1616 may collectively occupy less space than in a scenario where each spoke 1616 has a particular shape that does not lend itself to such a complimentary fit with adjacent spokes 1616.

[0104] To deploy the wheel 1600, the hub portions 1612 may be rotated in opposite directions relative to one another such that the wheel 1600 reaches the deployed position 1612. Because each spoke 1616 is located on a different hub portion 1612, the wheel 1600 may require less than 180 degrees of rotation to deploy from the folded position to the deployed position, which has been described in detail with respect to the wheel 800 and therefore will not be repeated here. Thus, the maximum rotation of the hub portions 1612 may be less than 180 degrees to deploy the wheel 1600 from the folded position to the deployed position.

[0105] To prevent further rotation of the hub portions 1612 relative to one another when the wheels 1600 reach the deployed position, the wheels 1600 may include a deployment limiting mechanism, as described above. Thus, each wheel portion 1610 may include a radial slot (not shown) on the hub portion 1612 from 1612, and a pin (not shown) on the hub portion 1612, which may be located on the opposite side of the slot from the central hole 1614. The arc length of each radial slot may generally be less than or equal to the deployment angle.

[0106] Similar to the example of FIG. 34 , each rim 1618 may include a tire portion (not shown) attached to each rim 1618. For example, each tire portion (not shown) may be a generally rectangular strip of rubber or similar resilient material attached to each rim 1618 along the length of the rim 1618. Each tire portion therefore generally follows the orientation and spatial position of each rim 1618 on the circular band 1617, as described above. Thus, when the wheel 1600 is deployed in its deployed position, the tire portions collectively define the tire of the wheel 1600. Similar to the example described above, the tire portions may be constructed from a resilient material, such as rubber. The tire portions may then be attached to the rim 1618 with adhesive, one or more fasteners, and / or one or more other types of attachment devices or procedures.

[0107] A tire (not shown) may be mounted on the wheel 1600 before or after the wheel is unfolded. The tire may be constructed from a solid piece of rubber or other type of plastic material that has sufficient elasticity to allow the tire to be mounted on the wheel 1600. Alternatively, the tire may be in the form of an inflatable tube that may be mounted on the rim 1618. Further alternatively, the tire may be attached to one or more rims 1618 such that the tire is maintained in its mounted configuration on the wheel 1600 in both the folded and unfolded positions of the wheel 1600.

[0108] 45-56 illustrate another example embodiment of a wheel 1900. The wheel 1900 has similar structure and / or components to the wheel 100 and other embodiments of the wheels described herein. Accordingly, similar terminology is used to describe similar components. With reference to FIGS. 45-46, the wheel 1900 includes a hub assembly 1902 connected to a tire or track assembly 1904. The track assembly 1904 is a tracked section or endless track defined by a plurality of interconnecting or interlocking track sections 1905. The track assembly 1904 is connected to an axle 1906 of the hub assembly 1902 by a plurality of wheel sections 1910. The plurality of wheel sections 1910 are aligned with and mounted on the axle 1906. It should also be understood that the wheel 1900 can be formed from one or more of the wheel sections 110, 610, 810, etc., or aspects or components thereof, as described herein.

[0109] As with other embodiments of the wheel disclosed herein, the wheel portion 1910 rotates about the axle 1906 to adjust the wheel 1900 between an unfolded position (or unfolded configuration) (see FIG. 45 ) and a folded position (or folded configuration) (see FIG. 46 ). As illustrated in FIG. 47 , folding the wheel 1900 from the unfolded position to the folded position achieves a reduction in the height H of the wheel 1900. The reduction in height H may be approximately 35% of the height of the wheel 1900 in the unfolded position. However, in other embodiments, the reduction in height H may be any suitable or targeted range of height reduction, including up to a 50% height reduction and / or a 10% height reduction beyond a 50% height reduction. By reducing the wheel height in the folded position, the ground contact patch of the wheel 1900 is reduced, which reduces the overall space or volume required to store the wheel 1900 (e.g., stored in a vehicle trunk, garage, basement, luggage, or any other suitable or desired location).

[0110] FIG. 48 illustrates one example of a wheel portion 1910. The wheel portion 1910 includes a hub portion 1912 defining a central bore 1914 configured to receive a portion of the axle 1906. The wheel portion 1910 includes a plurality of spokes 1916 protruding from the hub portion 1912 to a rim 1918. In the embodiment illustrated in FIG. 48, a first pair of spokes 1916a extend radially from the hub portion 1912 to define a first rim 1918a, while a second pair of spokes 1916b extend radially from the hub portion 1912 to define a second rim 1918b. The first spoke 1916a is positioned opposite the second spoke 1916b. In other embodiments, each wheel portion 1910 can have any suitable or desired number of spokes 1916 and / or rim 1918. The hub portion 1912 may also include one or more radial slots 1940 that correspond to and function in the same manner as the radial slots 140 (i.e., to limit the rotational distance of each wheel portion 1910 about the axle 1906).

[0111] 49-52 illustrate example embodiments of track sections 1905 for use with the wheel 1900. Referring to FIGS. 49-51, each track section 1905 has a generally arcuate cross-sectional shape to form the wheel 1900 when multiple track sections 1905 are interconnected. The track section 1905 includes an inner surface 1930 opposite an outer surface 1932. The inner surface 1930 is configured to engage the wheel section 1910, while the outer surface 1932 is configured to engage the ground, terrain, or other surface that the wheel 1900 traverses. Thus, the outer surface 1932 has a generally arcuate shape. In the illustrated embodiment, the features of the inner surface 1930 also have a generally arcuate shape. However, the cross-sectional shape of the inner surface 1930 can be any suitable shape for accommodating and enabling rotation of the wheel section 1910 in accordance with the disclosure provided herein.

[0112] The inner surface 1930 includes a plurality of ribs 1934. The ribs 1934 are generally parallel to one another and project radially away from the inner surface 1930 to define a plurality of circumferential grooves 1936. Each of the grooves 1936 is configured to receive the rims 1918 of one or more corresponding wheel portions 1910. Thus, the number of grooves 1936 (and thus the number of ribs 1934 defining the grooves 1936) depends on the number of wheel portions 1910 used in the wheel 1900. Any suitable number of grooves 1936 may be defined by each track portion 1905.

[0113] Each track portion 1905 includes a plurality of peripheral protrusions 1950 that define slots 1954. The protrusions 1950 and slots 1954 extend circumferentially along the track portion 1905 to facilitate connection between adjacent track portions 1905. With particular reference to FIG. 49 , the track portion 1905 includes a central member 1958 from which extend a plurality of protrusions 1950. The central member 1958 includes a first side 1962 opposite a second side 1966. The odd-numbered protrusions 1950 extend away from the first side 1962, while the even-numbered protrusions 1950 extend away from the second side 1966. In the illustrated embodiment, three protrusions 1950 extend circumferentially away from the first side 1962 and two protrusions 1950 extend circumferentially away from the second side 1966. Adjacent protrusions 1950 on each side 1962, 1966 are spaced apart to define a slot 1954. Each slot 1954 is sized and configured to receive a protrusion 1950 from an adjacent track section 1905. Similarly, each protrusion 1950 is sized to be received by the slot 1954 of an adjacent track section 1905. To facilitate connection of adjacent track sections 1905, each protrusion 1950 may include an opening 1970 extending therethrough. The openings 1970 are aligned along each side 1962, 1966 of the central member 1958 and configured to receive a dowel, shaft, or other suitable member 1974 (see FIG. 53 ) to secure or interconnect adjacent track sections 1905.

[0114] It should be appreciated that when the track portions 1905 are interconnected to define the track assembly 1904, each groove 1936 of the track portion 1905 cooperates with an associated circumferentially-aligned groove 1936 of an adjacent track portion 1905 to form a circumferential groove 1936 about the circumference of the wheel 1900. Similarly, each rib 1934 of the track portion 1905 cooperates with an associated circumferentially-aligned rib 1934 of an adjacent track portion 1905 to form a circumferential rib 1934 about the circumference of the wheel 1900. The circumferential rib 1934 maintains each wheel portion 1910, and more specifically the rim 1918 of each wheel portion 1910, within the appropriate or associated circumferential groove 1936. Additionally, the circumferential rib 1934 maintains one or more of the wheel portions 1910, and more specifically the rim 1918 of those wheel portions 1910, within the appropriate or associated circumferential groove 1936. Thus, as the wheel portion 1910 rotates about the axle 1906 and slides within (i.e., moves relative to) the respective circumferential groove 1936, the circumferential ribs 1934 help to keep the wheel portion 1910 within its respective circumferential groove 1936. In the illustrated embodiment, the rim 1918 has a generally square or rectangular cross-sectional shape when viewed along a cross-section taken axially parallel to the axle 1906. The grooves 1936 have a corresponding cross-sectional shape to receive the rim 1918 while also allowing the rim 1918 to slide within its respective groove 1936 (as the wheel portion 1910 rotates about the axle 1906). In other embodiments, the rim 1918 and the grooves 1936 may have any corresponding cross-sectional shapes. Generally, the grooves 1936 have a shape and / or size that corresponds to the shape and / or size of the rim 1918. Grooves 1936 may be approximately 0.10 inches to approximately 0.30 inches wide, and more preferably approximately 0.20 inches wide. Each rim 1918 and / or groove 1936 may also be sized to provide sufficient clearance between rim 1918 and rib 1934 that defines a portion of groove 1936 when rib 1934 is received by groove 1936.For example, the rim 1918 or groove 1936 may have a width to provide a clearance between the rim 1918 and the rib 1934 of approximately 0.010 inches to approximately 0.030 inches, and more preferably a clearance between the rim 1918 and the rib 1934 of approximately 0.014 inches.

[0115] 49 illustrates three protrusions 1950 on a first side 1962 of the central member 1958 and two protrusions 1950 on a second side 1966 of the central member 1958, in other embodiments, any number of protrusions may be used. However, in these other embodiments, an odd number of protrusions is provided on one side of the central member 1958 and an even number of protrusions is provided on the other, opposite side of the central member 1958. For example, one side of the central member 1958 may have 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc. protrusions 1950, while the other side of the central member 1958 may have 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, etc. protrusions 1950. Generally, one side of the central member 1958 will have N protrusions 1950, while the other opposite side of the central member 1958 will have N-1 (or N+1) protrusions 1950. While the track portion 1905 is defined as above with respect to the protrusions 1950, the track portion 1905 may be similarly defined with respect to the slots 1954. The track portion 1905 may have an even number of slots 1954 on a first side 1962 of the central member 1958 and an odd number of slots 1954 on a second side 1966 of the central member 1958. Generally, one side of the central member 1958 will have N slots 1954, while the other opposite side of the central member 1958 will have N-1 (or N+1) slots 1954.

[0116] 50 , each track portion 1905 can have any number of ribs 1934 and any number of grooves 1936. In the illustrated embodiment, each track portion 1905 includes nine ribs 1934 and eight grooves 1936. In other embodiments, each track portion 1905 can include any number of ribs 1934, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more. Furthermore, in other embodiments, each track portion 1905 can include any number of grooves 1936, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more. The number of grooves 1936 generally corresponds to the number of wheel portions 1910 (as each groove 1936 receives at least one wheel portion 1910). Additionally, each track portion 1905 may have any suitable distribution of ribs 1934 and grooves 1936 on the protrusions 1950. For example, in the illustrated embodiment, the plurality of protrusions 1950 have two ribs 1934 that define at least one groove 1936 and a portion of a second groove 1936, while one protrusion 1950 (the central protrusion 1950 that protrudes onto the first side 1962 of the central member 1958) has one rib 1934 that defines a portion of two grooves 1936. However, in other embodiments, the protrusions 1950 may have any suitable or desired number of ribs and / or channels (or portions thereof). Additionally, the protrusions 1950 may have different numbers of ribs 1934 and / or channels 1936 (e.g., one protrusion 1950 may have two ribs 1934, while another protrusion 1950 may have five ribs). Thus, any suitable or desired number of ribs 1934 and / or channels 1936 may be positioned on each protrusion 1950.

[0117] Each rib 1934 has a rib height 1978. In the illustrated embodiment, the rib height 1978 is generally constant as the ribs 1934 extend from the central member 1958. However, as the ribs 1934 reach the end of the projection 1950 opposite the central member 1958, the rib height 1978 decreases or has a curved end portion 1982. The curved portion 1982 helps avoid contact with the ribs 1934 of adjacent track sections 1905 when all of the track sections 1905 are interconnected to form the wheel 1900.

[0118] 53-54, a plurality of track sections 1905 are connected together to form a track assembly 1904, only a portion of which is shown. As previously disclosed, the track sections 1905 are connected by a securing member 1974 that is received by an opening 1970 in the protrusion 1950. While any suitable securing member 1974 may be used, preferably, the track sections 1905 may rotate about the securing member 1974 to facilitate folding of the wheel 1900.

[0119] 53-54 illustrate a portion 1986 of a track assembly 1904 formed by three track sections 1905. Any suitable number of track sections 1905 may be interconnected to form the track assembly 1904. For example, as illustrated in FIGS. 45-46 , 24 track sections 1905 define the track assembly 1904 that forms the wheel 1900. Stated another way, each track section 1905 extends approximately fifteen degrees (15°) along the wheel 1900 (i.e., 24 track sections divided by 360°). In other embodiments, each track section 1905 may extend any suitable number of degrees along the wheel 1900. Stated another way, any number of track sections 1905 may be interconnected to form the wheel 1900.

[0120] At least one wheel portion 1910a is secured or fixed to a portion 1986 of the track assembly 1904 to secure the track assembly 1904 to the hub assembly 1902 when the wheel 1900 is in the folded position. In other words, the wheel portion 1910a is not configured to slide within an associated groove 1936 of the track assembly 1904. FIGS. 53-54 illustrate a portion 1986 of the track assembly 1904 secured to the wheel portion 1910a. The portion 1986 includes a plurality of openings 1988 defined by associated extensions or protrusions 1989 that protrude from the ribs 1934 (or edges of the ribs 1934) on either side of the groove 1936. The openings 1988 are coaxially aligned on the sides of the groove 1936. An opening or rim opening 1990 is defined by a portion 1991 of the rim 1918 of the wheel portion 1910a (shown in FIG. 55). When the rim 1918 of the wheel portion 1910a is positioned within the groove 1936 (such that the groove 1936 receives the rim 1918), the rim opening 1990 is positioned in alignment with the respective openings 1988 on the rib 1934. A securing member 1992 (shown in FIGS. 58-59) is received by the aligned openings 1988, 1990 to secure the portion 1986 of the track assembly 1904 (and thus the track assembly 1904) to the wheel portion 1910a. The securement prevents the wheel portion 1910a from sliding within the groove 1936 of the track assembly 1904. Other embodiments of the wheel 1900 may include multiple wheel portions 1910a that are secured to and do not slide within grooves 1936 of the track assembly 1904. Additionally, any of the grooves 1936 may be configured to secure the track assembly 1904 to the hub assembly 1902. Accordingly, any one or more of the grooves 1936 may include multiple protrusions 1989 that protrude from opposing ribs 1934 and define openings 1988.

[0121] 56 , multiple spacers 1996 may be positioned along the axle 1906 between adjacent wheel sections 1910. The spacers 1996 may have a central bore 1997 that receives a portion of the axle 1906 and radial slots 1998 that are shaped similarly to and aligned with the radial slots 1940 (when assembled). The spacers 1996 may be constructed of or coated with polytetrafluoroethylene (PTFE) or a related polymer to reduce friction between the wheel sections 1910 as they are rotated about the axle between the unfolded and folded positions. Additionally, the spacers 1996 may help maintain proper spacing of the wheel sections 1910 within the hub assembly 1902.

[0122] It should also be understood that Figures 45-46 illustrate that four track portions 1905 engage or otherwise connect to each wheel portion 1910 when in the deployed position. In other embodiments, any number of track portions 1905 may be associated with each wheel portion 1910 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.).

[0123] 57-63 illustrate an alternative embodiment of wheel 1900a that is substantially similar to wheel 1900. Accordingly, like parts of wheel 1900 and wheel 1900a are referred to using the same reference numerals. Wheel 1900a includes a track assembly 1904 defined by a plurality of interlocking track portions 1905a. In addition, axle 1906 also carries end members or sprockets 1999.

[0124] 62-63 illustrate an example of a track portion 1905a used to define the track assembly 1904 of the wheel 1900a. The track portion 1905a shares similarities with the track portion 1905, and like parts are referred to using the same reference numerals. The track portion 1905a includes two protrusions 1950 on a first side 1962 of a central member 1958 and a single protrusion 1950 on a second side 1966 of the central member 1958. Thus, the two protrusions 1950 define one slot 1954 on the first side 1962, while there are two slots 1954 on the second side 1966. Referring to FIG. 63, the track portion 1905a defines the same number of ribs 1934 and grooves 1936 across its width as the track portion 1905. However, the distribution of ribs 1934 and grooves 1936 on each protrusion 1950 of track portion 1905a differs from track portion 1905. More specifically, the two protrusions 1950 on the first side 1962 of the central member 1958 each include two ribs 1934, each defining a portion of one groove 1936. The single protrusion 1950 on the second side 1966 of the central member 1958 includes five ribs 1934 and defines four grooves 1936. To carry the additional ribs 1934 and grooves 1936, the single protrusion 1950 on the second side 1966 of the central member 1958 has a greater width than each of the two protrusions 1950 on the first side 1962 of the central member 1958. In other embodiments of the track portion, each protrusion 1950 may have the same width or different widths. Further, each protrusion 1950 on the common side 1962, 1966 may have the same width or a different width. Additionally, in other embodiments, the number of ribs 1934 and grooves 1936 (or portions thereof) may be different or varied on each protrusion 1950. It should be understood that any number of ribs 1934 and / or grooves 1936 may be implemented or used in the wheel 1900, 1900a.

[0125] In operation, the wheel 1900 can be adjusted between an unfolded position (shown in FIG. 45 ) and a folded position (shown in FIG. 46 ). To adjust the wheel 1900 between positions, a user can rotate the hub assembly 1902, such as by applying a rotational force to the handles 202, 204 of the hubcap 200. Rotation of the hubcap 200 causes the wheel portion 1910 to rotate about the axle 1906, causing the wheel portion 1910 (and more specifically the rim 1918) to slide within a corresponding groove 1936 defined by the track portion 1905 of the track assembly 1904. It should be understood that while the wheel portion 1910 rotates about the axle 1906, at least one wheel portion 1910 a does not rotate because it is fixed to a portion of the track assembly 1904. This helps maintain the connection between the hub assembly 1902 and the track assembly 1904 (so that the track assembly 1904 does not come off the hub assembly 1902 during adjustment between the deployed and folded positions).

[0126] As the wheel section 1910 slides within the groove 1936 of the track assembly 1904 toward the folded position, the wheel section 1910 disengages and no longer supports a portion of the track assembly 1904. As the wheel section 1910 rotates into alignment about the axle 1906 (see FIG. 46 ), the portion of the track assembly 1904 that is no longer supported by the wheel section 1910 folds, causing the wheel section 1900 to deform into the folded position.

[0127] As the wheel unit 1910 slides within the groove 1936 of the track assembly 1904 toward the deployed position, the wheel unit 1910 engages and supports portions of the track assembly 1904. Slots 1940 and 1998 serve the same function as slot 140, helping to guide the distance and amount of rotation of the wheel unit 1910 about the axle 1906. When the wheel units 1910 are rotated completely about the axle 1906 (see FIG. 45 ), the wheels 1900 are in the deployed position. This arrangement advantageously deploys the wheel unit 1910 without requiring any additional user interaction. Additionally, the spaced wheel units 1910 maintain the circular shape (i.e., 360 degrees) of the wheels 1900 to maintain constant contact with the ground (or terrain, or other surface engaged by the track assembly 1904).

[0128] Referring to FIG. 42 , an example method 1700 for constructing a wheel is shown. The method includes forming a plurality of wheel sections (block 1702) and assembling the wheel sections onto an axle (block 1704). The method 1700 may also include forming a tire (not shown) and / or mounting or attaching the tire onto the wheel section (not shown), and / or mounting or attaching a track assembly onto the wheel section (not shown). Wheels according to the present disclosure may be constructed from any metal or metal alloy, plastic, composite material, wood, or combinations thereof. Each wheel section, such as wheel section 110 of wheel 100, may be integrally formed from a plastic material by injection molding. The injection molding process may use a mold having a cavity that defines the wheel section. Molten plastic material is injected into the mold and cooled. The molded and cooled wheel section is then removed from the mold. The molded wheel section may also be smoothed or cleaned to remove any injection molding residue. Alternatively, the wheel section may be constructed by stamping (i.e., punching, blanking, embossing, bending, flanging, coining, or casting using a mechanical or stamping press), forging, machining, or a combination thereof, or other processes used to manufacture metal, composite, plastic, or wood sections. Each wheel section may be integrally formed. Alternatively, the components of each wheel section may be formed by the processes and materials described herein and assembled to form the wheel section. For example, the wheel section 110 may be formed by assembling the hub section 212, spokes 216, and rim 218, which are separately manufactured. The hub section 212, one or more spokes 216, and rim 218 may be attached to one another by one or more adhesives, welding, soldering, and / or fasteners. The disclosed materials and / or processes may be used to manufacture any of the disclosed wheel, axle, and / or tire components. Tires may be manufactured from a resilient material to provide shock absorption for a push cart to which one or more of the disclosed wheels are attached. Tires may be formed from rubber or other plastic materials.The tire may be formed as an inflatable tube or a solid flexible material.

[0129] Referring to FIG. 43 , a golf push cart 1800 for supporting and transporting a golf club bag is shown having wheels 100. While the push cart 1800 is shown with wheels 100, any of the wheels described herein may be used with the golf push cart. The golf push cart 1800 may include a frame 1810 upon which a golf club bag (not shown) may rest. The golf club bag may also be supported by a bottom support 1812, a bottom side support 1813, and a top side support 1814. The frame 1810 may also include one or more straps (not shown) for securing the golf club bag to the frame 1810. The push cart 1800 may further include two feet 1820 and 1822 extending outwardly from the frame 1810 in opposite directions. Each foot supports a wheel 100. The frame may also include a hinge 1824 having two hinge rods 1826 and 1828 by which the feet 1820 and 1822 may be pivoted and folded so that the feet extend along the frame 1810. The frame 1810 may also be hinged to fold to provide a compact golf cart 1800 for traveling to and from a golf course, driving range, or any golf-related facility. The folded golf cart 1800 is shown in FIG. 44. To further reduce the size of the golf cart 1800, the wheels 100 may be folded as detailed herein. Furthermore, the wheels 100 may be removed from the cart 1800 and stored separately. Thus, the wheels 100, or any wheels described herein, may be used to reduce the size of any vehicle, such as a golf cart, for easier storage and / or transportation. Alternatively, the golf club bag (not shown) may include attachment points or axles for attaching two foldable wheels directly to the golf club bag as detailed herein. For example, the golf club bag may be provided with two foldable wheels that can be stored within one or more pockets of the golf club bag.A person may carry the golf club bag, or may attach two wheels to axles on the golf club bag, unfold the wheels, and use the wheels to pull the golf club bag. The use of foldable wheels as detailed herein is not limited to golf push carts. The foldable wheels as detailed herein may also be used on kayak carts, shopping carts, small wagons typically used by children, any type of luggage, luggage carts, coolers, and / or any other wheeled utility carts, trailers, enclosed storage devices, or vehicles.

[0130] 64-68 , another example wheel 2000 is shown. The wheel 2000 includes a hub assembly 2002. The hub assembly 2002 includes a plurality of spokes 2016 extending radially from a hub portion 2012. The hub portion 2012, the spokes 2016, and the rim 2018 may form a wheel plane. The wheel 2000 is configured so that the hub portion, the spokes, and the rim do not rotate relative to each other. By varying the length of the spokes, the rim 2018 may be moved toward or away from the hub portion.

[0131] The wheel diameter may be measured in the wheel plane from a first outer edge of the rim 2018 through the wheel center to a second outer edge of the rim 2018 opposite the first outer edge. The wheel 2000 may also include an axle 2006 (not shown) to which the hub assembly 2002 is rotatably mounted. The wheel 2000 may include a tire (not shown) mountable to the hub assembly 2002. Alternatively, the wheel 2000 may include multiple tire portions as described above with respect to the wheel 1500. Further alternatively, the wheel 2000 may operate without a tire.

[0132] The wheel 2000 may include multiple rims 2018 that can be configured to define a path on a circumference or circular band (not shown) having a width. The rim width may be measured in the wheel plane in a direction toward the wheel center. The width may vary along each rim 2018 or may be constant along each rim 2018. The path defined by the rims 2018 may be substantially continuous. The circular band defines a circular contact area between the wheel 2000 and the ground, similar to a tire. In one example, each rim 2018 is positioned completely flush with the circular band. In the unfolded position of the wheel 2000, each rim 2018 may be oriented such that at least one point on at least one rim 2018 simultaneously contacts the horizontal ground. In some embodiments, there are several orientations of the wheel 2000 such that at least one point on at least two rims simultaneously contacts the horizontal ground.

[0133] In some embodiments, as shown in the example of FIG. 64 , in the deployed position, each rim 2018 may have radial overlap with an adjacent rim 2018. Each rim 2018 may be radially spaced apart from an adjacent rim 2018, as long as the space does not provide a clearance large enough to substantially prevent or impede the wheel 2000 from rolling generally smoothly over the ground. Alternatively, each rim 2018 may have no radial clearance with respect to an adjacent rim. Each rim 2018 may be curved such that points on adjacent rims 2018 spaced apart at a particular angle lie on the circular band 2017. Thus, as shown in FIG. 64 , the rims 2018 define a portion of a generally continuous circular path in the deployed position of the wheel 2000. In other words, the curvature of each rim 2018 in the deployed position may generally follow a curvature relative to a circle that defines the plane of the wheel 2000.

[0134] Each rim 2018 is attached to the central hub portion 2012 by at least one spoke 2016. In some embodiments, there may be the same number of rims 2018 and spokes 2016. For example, in FIG. 64, there are four rims 2018 and four spokes 2016. In other embodiments, there may be at least two spokes 2016. For example, the wheel 2000 may include one spoke, two spokes, three spokes, four spokes, five spokes, six spokes, seven spokes, eight spokes, nine spokes, or ten or more spokes. Each spoke 2016 includes an inner spoke portion 2015 and an outer spoke portion 2019 that is received in the inner spoke portion 2015 when moving from the unfolded position to the folded position.

[0135] Each rim 2018 may include at least one thin peripheral region 2023. In many embodiments, each rim 2018 includes a central portion and two ends. The rims 2018 may include a first end 2023a and a second end 2023b. In both the folded and unfolded configurations, the first end 2023a of one rim 2018 may overlap the second end 2023b of an adjacent rim 2018. Adjacent rims 2018 may overlap more when the wheel 2000 is in the folded configuration than when the wheel 2000 is in the unfolded configuration. At least one of the two peripheral regions may include a thin peripheral region. The width of the rim, measured perpendicular to the wheel plane, is smaller in the thin peripheral region than in the central portion. In some embodiments, as shown in FIGS. 64 and 65 , a recess may be defined by one side of each rim 2018 on each end to form a low-profile peripheral region 2023. In some such embodiments, both low-profile peripheral regions 2023 are on the same side of the rim 2018. In other embodiments, the low-profile peripheral regions 2023 are on different sides of the rim 2018. In the unfolded and folded configurations, at least a portion of the low-profile peripheral region 2023 of one rim 2018 may overlap a portion of the low-profile peripheral region 2023 of an adjacent rim 2018. In some embodiments, adjacent low-profile peripheral regions 2023 may only overlap in the folded configuration, not in the unfolded configuration. The low-profile peripheral regions 2023 of two adjacent rims 2018 may overlap along the recess 2023 at a different point in the folded configuration than in the unfolded configuration. As shown in FIG. 68, in the folded configuration, the rims 2018 may overlap and extend beyond adjacent rims 2018 .

[0136] 66 and 67, the diameter D of the wheel 2000 in the folded configuration C is the diameter D of the wheel 2000 in the deployed configuration EThe diameter of the wheel may be reduced by between 15% and 30%. The diameter may be reduced by between 15% and 20%, between 20% and 25%, or between 25% and 30%. For example, in some embodiments, the diameter of the wheel 2000 is reduced by approximately 22%. In the folded position, the surface area of ​​the wheel 2000 may be reduced by between 30% and 50%. For example, the surface area of ​​the wheel 2000 may be reduced by between 30% and 35%, between 35% and 40%, between 40% and 45%, or between 45% and 50%. In one example, in the folded configuration, the surface area of ​​the wheel 2000 may be reduced by 39%. The width of the wheel 2000 may remain the same in the unfolded and folded configurations.

[0137] To unfold the wheel 2000, the spokes 2016 may be extended. When converting the wheel 2000 from a folded to an unfolded configuration, or from an unfolded to a folded configuration, the outer spoke portions 2019 are slidable relative to the inner spoke portions 2015. In some embodiments, the spokes 2016 may be extended by applying a force to at least one spoke 2016 in a direction away from the hub portion 2012. Alternatively, the wheel 2000 may be unfolded by rotating a central hub portion attachment (not shown). When going from the folded to the unfolded position, the hub portion 2012, spokes 2016, and rim 2018 may remain substantially in the same plane.

[0138] To prevent further extension of the spokes after the wheel 2000 reaches the deployed position, the wheel 2000 may include an expansion limiting mechanism. In some embodiments, a locking mechanism may serve as the expansion limiting mechanism. The expansion limiting mechanism may be engaged to prevent the wheel 2000 from returning to the folded position during use. In some embodiments, the expansion limiting mechanism may automatically engage once the wheel 2000 reaches the deployed position. In other embodiments, the expansion limiting mechanism may be manually engaged at any point during spoke extension to maintain any desired wheel diameter. The user can unlock the wheel by performing an operation on one or more parts of the locking mechanism to disengage the lock, such as by pushing, twisting, pulling, or moving the parts.

[0139] 69 and 70 , the central hub portion 2112 may include an extension system. The extension system is a mechanism responsible for allowing the spokes 2116 to extend. The extension system may include at least one spoke extension 2120. A first end 2122 of the spoke extension 2120 may be rotatably attached to the central hub portion 2112. The inner end of each spoke 2116 may be rotatably fastened to a second end 2124 of the spoke extension 2120. In the deployed position, the spoke extension 2120 forms part of the spoke and is integrated into the length of the spoke. In many embodiments, as shown in FIG. 69 , in the folded configuration, the spoke extensions 2120 form an acute angle with the spokes 2116. When moving from the folded configuration to the deployed configuration, the extensions 2120 rotate about their second ends 2124 and move away from the center of the hub portion 2112. In some embodiments, when moving from the folded configuration to the deployed configuration, the extensions 2120 may rotate between 15 and 40 degrees. For example, the extensions may rotate between 15 and 20 degrees, between 20 and 25 degrees, between 25 and 30 degrees, between 30 and 35 degrees, or between 35 and 40 degrees. In some embodiments, as shown in FIG. 70 , in the deployed configuration, the spoke extensions 2120 form an obtuse angle with the spokes 2116. In some embodiments, in the deployed position, the spoke extensions 2120 form a 180-degree angle with the spokes 2116. The angle between the spoke extensions 2120 and the spokes 2116 is larger in the folded position than in the deployed position.

[0140] Similar to the example of FIG. 34 , each rim 2018, 2118 may include a tire portion (not shown) attached to the respective rim 2018, 2118. For example, each tire portion may be a generally rectangular strip of rubber or similar resilient material attached to the respective rim 2018, 2118 along the length of the rim 2018, 2118. Thus, each tire portion generally follows the orientation and spatial position of the respective rim 2018, 2118 on the circular band as described above. Thus, when the wheel 2000, 2100 is deployed in the deployed position, the tire portions collectively define the tire of the wheel 1600. Similar to the example described above, the tire portions may be constructed from a resilient material such as rubber. The tire portions may then be attached to the rim 2018, 2118 with adhesive, one or more fasteners, and / or one or more other types of attachment devices or procedures.

[0141] A tire (not shown) may be mounted on wheel 2000 before or after the wheel is unfolded. The tire may be constructed from a solid piece of rubber or other type of plastic material that has sufficient elasticity to allow the tire to be mounted on wheel 2000. Alternatively, the tire may be in the form of an inflatable tube that may be mounted on rim 2018. Further alternatively, the tire may be attached to one or more rims 2018 such that the tire is maintained in a mounted configuration on wheel 2000 in both the folded and unfolded positions of wheel 2000.

[0142] Referring to FIG. 71 , another embodiment of wheel 2200 is shown. This wheel may be similar in many respects to wheel 2100. Wheel 2200 includes a locking system. The locking system may include an externally accessible locking element 2221 and at least one aperture 2225 capable of receiving the externally accessible locking element 2221. The locking mechanism may be operated by engaging / disengaging, manipulating, or installing / removing the externally accessible locking element. The locking element 2221 of wheel 2200 is a threaded screw 2227. Other embodiments may include different externally accessible locking elements, such as buttons, pins, clamps, or other fasteners. Apertures 2225 of wheel 2100 are located in each spoke 2216. In other embodiments, apertures 2225 may be present in the hub assembly 2202, the spokes 2216, or the rim. When wheel 2100 is in the deployed configuration, the spokes 2216 may be mechanically locked. In some of these embodiments, the spokes 2216 may be mechanically locked when the wheel 2200 is in the folded configuration. In the locked state, the outer spoke portions 2219 cannot slide relative to the inner spoke portions 2215, preventing the spokes 2216 from unfolding or collapsing. To unfold or fold the wheel 2200, the wheel must be unlocked. To unlock the wheel 2200, the user moves the locking element 2221 away from the wheel, thereby releasing it from the locked position. The threaded screw 2227 may be moved by twisting it in one direction until it is released from the holes 2225. Once released, the outer spoke portions may slide relative to the inner spoke portions. To lock the wheel 2200, the screw may be twisted in a second direction to engage the desired holes 2225.

[0143] Referring to FIG. 72 , another embodiment of a wheel 2300 is shown. This wheel may be similar in many respects to the wheel 2100. Like the wheel 2100, the wheel 2300 includes a locking system. The locking system may include an externally accessible locking element 2321 and at least one aperture 2325 capable of receiving the externally accessible locking element 2321. The locking mechanism may be operated by the externally accessible locking element. The locking element 2321 of the wheel 2300 is a spring plunger 2327. Other embodiments may include a different externally accessible locking element, such as a button, pin, clamp, or other fastener. Each spoke 2316 includes at least one aperture 2325. In other embodiments, the apertures may be present in the hub assembly, the spokes, or the rim. The spokes 2316 may be mechanically locked when the wheel 2300 is in the unfolded configuration. In some of these embodiments, the spokes 2316 may be mechanically locked when the wheel 2300 is in the folded configuration. In the locked state, the outer spoke portion 2319 cannot slide relative to the inner spoke portion 2315, and therefore the spokes 2316 cannot be deployed or folded. To deploy or fold the wheel 2200, the wheel must be unlocked. To unlock the wheel, the user moves the locking element 2321 away from the wheel 2300, thereby releasing it from the locked position. The spring plunger 2327 may be moved by lifting it away from the spokes 2316 until it is released from the holes 2325. Once released, the outer spoke portion 2319 can slide relative to the inner spoke portion 2315. To lock the wheel 2300, the spring plunger 2327 may be released from its lifted position and engaged with the desired hole 2325.

[0144] 73-77, another example wheel 2400 is shown. The wheel 2400 includes a hub assembly 2402. The hub assembly 2402 may include a plurality of spokes 2416 extending radially from a hub portion 2412. Each spoke 2416 of the plurality of spokes may be attached to a rim 2418. In some embodiments, each spoke 2416 of the plurality of spokes may be attached to two or more rims 2418. In other embodiments, two or more spokes 2416 of the plurality of spokes may be attached to the same rim or to multiple identical rims 2418. The wheel 2400 is configured such that the hub portion and spokes do not rotate relative to each other. However, the rim may be partially rotatable relative to the spokes when transitioning between the folded and unfolded configurations.

[0145] The hub assembly 2402, spokes 2416, and rim 2018 may form a wheel plane. A wheel diameter may be measured in the wheel plane from a first outer edge of the rim 2018 through the wheel center to a second outer edge of the rim 2018 opposite the first outer edge. The wheel 2400 may include a tire (not shown) mountable to the hub assembly 2402. Alternatively, the wheel 2400 may include multiple tire portions, as described above with respect to the wheel 1500. Further alternatively, the wheel 2400 may operate without a tire. The wheel 2400 may also include an axle (not shown) to which the hub assembly 2402 is rotatably mounted.

[0146] The wheel 2400 includes multiple rims 2418 configured to define a path on a circumference or circular band having a width. The width may vary along each rim 2418 or may remain constant along each rim 2418. The path defined by the rims 2418 may be substantially continuous. The circular band may define a circular contact area between the wheel 2400 and the ground, similar to a tire. In one example, each rim 2418 is positioned completely flush with the circular band. In the deployed position of the wheel 2400, each rim 2418 may be oriented such that at least one point on at least one rim 2418 contacts the ground. In some embodiments, there are several orientations of the wheel 2400 such that at least one point on at least two rims simultaneously contacts the horizontal ground.

[0147] In some embodiments, as shown in the example of FIG. 73 , in the deployed position, each rim 2418 may have radial overlap with an adjacent rim 2418. Each rim 2418 may be radially spaced apart from an adjacent rim 2418, as long as the space does not provide a clearance large enough to substantially prevent or impede the wheel 2400 from rolling generally smoothly over the ground. Alternatively, each rim 2418 may have no radial clearance with respect to an adjacent rim. Each rim 2418 may be curved such that points on adjacent rims 2418 spaced apart at a particular angle lie on a circular band 2417. Thus, as shown in FIG. 73 , the rims 2418 define a portion of a generally continuous circular path in the deployed position of the wheel 2400. In other words, the curvature of each rim 2418 in the deployed position may generally follow the curvature of a circle that defines the plane of the wheel 2400.

[0148] Each rim 2418 is attached to the central hub portion 2412 by at least one spoke 2416. In some embodiments, there may be the same number of rims 2418 and spokes 2416. For example, there may be four rims 2418 and four spokes 2416. In many embodiments, there may be at least two spokes 2416. In some examples, the wheel 2400 may include two spokes, four spokes, six spokes, eight spokes, ten spokes, twelve spokes, fourteen spokes, or sixteen spokes.

[0149] The wheel 2400 may include at least one first spoke 2430 and at least one second spoke 2432. Each first spoke 2430 may include a first inner spoke portion 2433 and a first outer spoke portion 2435. Each first outer spoke portion 2435 is slidably received in the first inner spoke portion 2433 when moving from the unfolded position to the folded position. Each second spoke 2432 may include a second inner spoke portion 2443 and a second outer spoke portion 2445. Each second outer spoke portion 2445 is slidably received in the second inner spoke portion 2443 when moving from the unfolded position to the folded position.

[0150] The first spoke 2430 and the second spoke 2432 may have different cross-sectional shapes and widths. In other embodiments, the first spoke 2430 and the second spoke 2432 may have the same cross-sectional shape. In the embodiment shown in FIGS. 73-77, the first spoke 2430 has a rectangular cross-section, while the second spoke 2432 has a circular cross-section. In other embodiments, the first spoke 2430 and the second spoke 2432 may have any cross-sectional shape, including rectangular, elliptical, circular, or another polygonal shape. The cross-sectional width of the first spoke may be greater than the cross-sectional diameter of the second spoke. The first spoke 2430 and the second spoke 2432 may have substantially similar lengths. One end of each rim is attached to the first spoke and the other end is attached to the second spoke. The outermost end of each first outer spoke portion 2435 may be fixedly or hingedly secured to at least one rim 2418. In some embodiments, the rims 2418 may rotate about their points of attachment to the first spokes 2430. The outermost ends of each second outer spoke portion 2445 may be slidably attached to at least one rim 2418. As one example, in the embodiment shown in FIG. 69, each first spoke 2430 is attached to two rims 2418, and each second spoke 2432 is attached to two rims 2430.

[0151] Each rim 2418 may include an elongated notch 2450. In some embodiments, as shown in FIGS. 73-77 , the notch 2423 penetrates the rim near its end. In both the folded and unfolded configurations, a portion of the notch 2423 of one rim 2418 may overlap a portion of the notch 2423 of an adjacent rim 2418. The notches 2423 of two adjacent rims 2418 may overlap at different points along the notch 2423 in the folded configuration than in the unfolded configuration. As shown in FIG. 74 , in the folded configuration, a rim 2418 may overlap and extend beyond the adjacent rim 2418. In most of these embodiments, the rims 2418 may define a circle in the unfolded configuration but not in the folded configuration.

[0152] To unfold the wheel 2400, the spokes 2430, 2432 may be extended. When switching the wheel 2400 from a folded to an unfolded configuration, or from an unfolded to a folded configuration, the outer spoke portions 2435, 2445 are slidable relative to the inner spoke portions 2433, 2443. The spokes 2430, 2432 may be extended by applying a force to at least one spoke 2416 in a direction away from the hub portion 2412. When transitioning from the folded to the unfolded position, the hub portion 2412, spokes 2430, 2432, and rim 2418 may remain substantially in the same plane.

[0153] 75 and 76, the diameter DC of the wheel 2400 in the folded configuration may be smaller than the diameter DE of the wheel 2400 in the unfolded configuration. The diameter of the wheel may be reduced by between 20% and 50%. For example, in some embodiments, the diameter of the wheel 2400 is reduced by approximately 35%. The surface area of ​​the wheel 2400 may be reduced by between 50% and 70%. For example, the surface area of ​​the wheel 2400 may be reduced by between 50% and 55%, between 55% and 60%, between 60% and 65%, or between 65% and 70%. In some embodiments, the surface area of ​​the wheel 2400 may be reduced by approximately 57% in the folded configuration. The width of the wheel 2400 may remain the same in the unfolded and folded configurations.

[0154] To unfold the wheel 2400, the spokes 2416 may be extended. The outer spoke portions are slidable relative to the inner spoke portions when switching the wheel 2400 from a folded to an unfolded configuration, or from an unfolded to a folded configuration. The spokes may be extended by applying force to at least one spoke 2416 in a direction away from the hub portion 2412. When transitioning from the folded to the unfolded position, the hub portion 2412, spokes 2416, and rim 2418 may remain substantially in the same plane.

[0155] The central hub portion of the wheel 2400 may include an extension system that allows the spokes to extend and retract. Referring to Figures 69 and 70, the extension system of the wheel 2400 may be substantially similar to the extension system of the wheel 2100 disclosed above.

[0156] Wheel 2400 may include a deployment limiting mechanism to prevent further extension of the spokes after wheel 2400 reaches the deployed position. The deployment limiting mechanism of wheel 2400 may be substantially similar to the deployment limiting mechanism of wheel 2000 disclosed above.

[0157] Wheel 2400 may further include a locking mechanism that prevents folding or unfolding of wheel 2400 during use. Referring to Figures 71 and 72, the locking mechanism of wheel 2400 may be substantially similar to the locking mechanism of wheel 2200 or wheel 2300.

[0158] Similar to the example of FIG. 34 , each rim 2418 may include a tire portion (not shown) attached to each rim 2418. For example, each tire portion may be a generally rectangular strip of rubber or similar resilient material attached to each rim 2418 along the length of the rim 2418. Each tire portion therefore generally follows the orientation and spatial position of each rim 2418 on the circular band, as described above. Thus, when the wheel 2400 is deployed in the deployed position, the tire portions collectively define the tire of the wheel 1600. Similar to the example described above, the tire portions may be constructed from a resilient material, such as rubber. The tire portions may then be attached to the rim 2418 with adhesive, one or more fasteners, and / or one or more other types of attachment devices or procedures.

[0159] A tire (not shown) may be mounted on wheel 2400 before or after the wheel is unfolded. The tire may be constructed from a solid piece of rubber or other type of plastic material that has sufficient elasticity to allow the tire to be mounted on wheel 2400. Alternatively, the tire may be in the form of an inflatable tube that may be mounted on rim 2418. Further alternatively, the tire may be attached to one or more rims 2418 such that the tire is maintained in a mounted configuration on wheel 2400 in both the folded and unfolded positions.

[0160] 78 and 79, another example wheel 2500 is shown. Certain aspects of wheel 2500 may be similar to wheel 100 shown in FIGS. 1-3. Accordingly, similar parts of wheel 100 and wheel 2500 are designated with like reference numerals. Wheel 2500 includes a hub assembly 2502 and an axle 2506 on which hub assembly 2502 is rotatably mounted.

[0161] 78 and 79 show the wheel 2500 in the unfolded and folded positions, respectively. As with the embodiment of FIGS. 1-3, each wheel unit 2510 may be freely rotatable about an axle 2506 to allow the wheel unit 2510 to be deployed from the folded position to the unfolded position. In the folded configuration, the surface area of ​​the wheel 2500 may be reduced by between 40% and 60% relative to the surface area of ​​the wheel 2500 in the unfolded configuration. For example, the surface area of ​​the wheel in the folded configuration may be reduced by between 40% and 45%, between 45% and 50%, between 50% and 55%, or between 55% and 60%. In some embodiments, the surface area of ​​the wheel 2500 may be reduced by approximately 52% in the folded configuration.

[0162] The hub assembly 2502 includes a plurality of stacked wheel sections 2510. Each wheel section 2510 includes a hub section 2512 with a central bore 2514. The wheel sections 2510 may be concentrically stacked such that the central bores 2514 are axially aligned to form an elongated bore for receiving the axle 2506. Each wheel section 2510 may include spokes 2516 and a rim 2518. In the example of FIGS. 78-80 , each wheel section 2510 has a first spoke 2516 projecting radially from the hub section 2512 for coupling to a first rim 2518, and a second spoke 2516 projecting radially from the hub section 2512 opposite the first spoke 2516 for coupling to a second rim 2518. Each wheel section 2510 may include any number of spokes 2516 extending from the hub section 2512 to one or more rims 2518. In some embodiments, each wheel portion may include one, two, three, or four spokes extending from the hub portion 2512 to one or more rims 2518.

[0163] The spokes 2516 may be any shape. For example, each spoke 2516 may be straight, bent, and / or have a curve in one or more locations along the length of the spoke. In the example of FIGS. 78-80, the spokes 2516 may be curved to act as a spring when the wheel 2500 is in use. Thus, when a force is exerted on the rim 2518 during operation of the wheel 2500, the curved shape of each spoke 2516 promotes elastic bending of the spoke 2516 so that the spoke 2516 provides a shock-absorbing function. The curvature of the spokes 2516 may be "S" shaped, as in the example of FIGS. 78-80, or may be a combination of straight and curved portions. The cross section of the spokes 2516 may be any shape. For example, the cross section of the spokes 2516 may be square, rectangular, circular, hexagonal, or any other polygonal shape.

[0164] Increasing the number of contact points between the wheel 2500 and the ground may increase the stability of the wheel 2500. Each rim 2518 may contact the ground at one contact point. Providing multiple contact points, i.e., multiple rims 2518, that contact the ground at any one time may increase the stability of the wheel 2500. In other words, increasing the number of contact points with the ground at any one time during the operation of the wheel 2500 increases the width of the wheel 2500, thereby increasing the number of wheel sections 2510 that may be used to form the wheel 2500. Increasing the number of wheel sections 2510 may increase the stability of the wheel 2500 and / or the weight that the wheel 2500 may support. However, increasing the number of wheel sections 2510 may also increase the size and / or weight of the wheel 2500 in the folded position. Therefore, the size of each wheel section 2510, and other characteristics of each wheel section 2510 as described herein, may be determined depending on the size and load of a cart to which one or more wheels 2500 may be attached.

[0165] 78-80 show wheel 2500 including a tire portion on each rim 2518. When wheel 2500 is deployed in a deployed position, tire portions 2504 collectively define the tire of wheel 2500. Thus, the tire of wheel 2500 is defined by the plurality of tire portions 2504 and any gaps that may exist between adjacent tire portions 2504. The tire portions may be constructed from any durable material. In some examples, the tire portions may be constructed from a resilient material such as rubber or plastic. In some embodiments, the tire portions may be integrally attached to rim 2518. In other embodiments, the tire portions may be attached to rim 2518 with adhesive, mechanical fasteners, molding, or bonding.

[0166] Although a particular order of acts is described above, these acts may be performed in other chronological orders. For example, multiple acts described above may be performed sequentially, in parallel, or simultaneously. Alternatively, multiple acts may be performed in the reverse order. Furthermore, one or more acts described above may not be performed at all. The apparatus, methods, and articles of manufacturing described herein are not limited in this respect.

[0167] While the invention has been described in various embodiments, it will be understood that the invention is capable of further modifications. This application includes any variations, uses, or adaptations of the invention described below, generally including the principles of the invention and including departures from the present disclosure within known and customary practice in the art to which this invention pertains. Item 1: A wheel comprising: a hub portion defining an axis of rotation; a plurality of spokes extending from the hub; and a plurality of rim portions, each spoke of the plurality of spokes having an inner spoke portion and an outer spoke portion, each inner spoke portion configured to receive one outer spoke portion; each spoke of the plurality of spokes engaging with at least one rim portion of the plurality of rim portions; the plurality of rim portions defining a circle in an unfolded configuration; the plurality of rim portions defining a plane of rotation; the rim portions having a thickness measured in a direction perpendicular to the plane of rotation; each rim portion of the plurality of rim portions having a central portion and two end portions; the thickness of the two end portions of each rim portion of the plurality of rim portions being less than the thickness of the central portion; in a folded configuration, a first end of each rim portion overlaps a second end of an adjacent rim portion; and the foldable wheel is configured in an unfolded configuration or a folded configuration.

[0168] Clause 2: The wheel of clause 1, wherein in both the unfolded and folded configurations, portions of two adjacent rim sections of the plurality of rim sections overlap each other.

[0169] Clause 3: The wheel of clause 2, wherein the overlap of adjacent rim sections is greater in the folded configuration than in the unfolded configuration.

[0170] Clause 4: The wheel of clause 1, further comprising an axle, the axle configured to removably receive the hub portion of each wheel portion by being insertable into a central hole of each wheel portion concentric with the rotational axis of the wheel portion, and the wheel being rotatable relative to the axle.

[0171] Clause 5: The wheel of clause 1, wherein the plurality of rims define a circle in the unfolded configuration.

[0172] Clause 6: The wheel of clause 5, wherein in the folded configuration, each rim of the plurality of rims defines a segment of the circle defined in the unfolded configuration.

[0173] Clause 7: The wheel of clause 1, wherein each end defines a recess, and each recess in a single rim is defined in the same face of said rim.

[0174] Clause 8: The wheel of clause 7, wherein the recesses of adjacent rims are defined on opposite faces of the rims.

[0175] Clause 9: The wheel of clause 1, wherein the hub and the inner spoke portion are integrally formed, and at least one outer spoke portion and at least one rim portion are integrally formed.

[0176] Clause 10: The wheel of clause 1, further comprising a tire configured to be mountable on the rim portion in the folded configuration or the unfolded configuration.

[0177] Clause 11: The wheel of clause 10, wherein each rim portion includes a tire portion.

[0178] Clause 12: The wheel of clause 1, wherein the hub portion, the plurality of spokes, and the rim portion are non-rotatable relative to one another.

[0179] Clause 13: The wheel of clause 13, wherein each spoke is attached to one rim portion at the central portion of the rim portion.

Claims

1. A wheel switchable between an unfolded configuration and a folded configuration, comprising: a hub portion defining an axis of rotation; a plurality of spokes extending from the hub portion; a plurality of rim portions; each spoke of the plurality of spokes having an inner spoke portion and an outer spoke portion; Each inner spoke portion is configured to receive one outer spoke portion; each spoke of the plurality of spokes engages at least one rim portion of the plurality of rim portions; the plurality of rim portions define a circle in the deployed configuration; the plurality of rim portions define a plane of rotation; each rim portion of the plurality of rim portions has a thickness measured in a direction perpendicular to the plane of rotation; each rim portion of the plurality of rim portions has a central portion and two end portions; a thickness of each of the two ends of the plurality of rim portions is less than a thickness of the central portion; in the folded configuration, the first end of each rim portion overlaps the second end of an adjacent rim portion; When the wheel transitions from the unfolded configuration to the folded configuration, each rim portion of the plurality of rim portions moves toward the rotation axis. wheel.

2. The wheel of claim 1 , wherein in both the unfolded and folded configurations, a portion of two adjacent rim portions of the plurality of rim portions overlap each other.

3. 3. The wheel of claim 2, wherein the overlap of adjacent rim portions is greater in the folded configuration than in the unfolded configuration.

4. The vehicle further includes an axle and a plurality of wheel portions, Each wheel portion of the plurality of wheel portions includes a rim portion and spokes; the axle is configured to be insertable into a central bore of each wheel portion concentric with the axis of rotation of the wheel portion to removably receive the hub portion of each wheel portion; A wheel according to any one of claims 1 to 3, wherein the wheel is rotatable about the axle.

5. The wheel of claim 1 , wherein in the folded configuration, each rim portion of the plurality of rim portions defines a segment of the circle defined in the unfolded configuration.

6. Each of the plurality of rim portions defines a recess at each of the two ends, A wheel according to any one of the preceding claims, wherein in each rim portion of the plurality of rim portions the recess is defined in the same face.

7. A wheel as described in claim 6, wherein in adjacent rim portions of the plurality of rim portions, adjacent recesses are defined on opposite faces.

8. the hub and the inner spoke portion are integrally formed; A wheel according to any one of the preceding claims, wherein at least one outer spoke portion and at least one rim portion are integrally formed.

9. 9. The wheel of claim 1, further comprising a tire configured to be mountable to said plurality of rim portions in said folded configuration or in said unfolded configuration.

10. The tire is collectively defined by a plurality of tire portions, The wheel of claim 9 , wherein each tire portion of the plurality of tire portions is mounted to a respective rim portion of the plurality of rim portions.

11. A wheel according to any preceding claim, wherein the hub portion, the plurality of spokes and the plurality of rim portions are non-rotatable relative to one another.

12. A wheel as described in any one of claims 1 to 11, wherein each spoke of the plurality of spokes is attached to the central portion of one of the plurality of rim portions.

13. A wheel as described in any one of claims 1 to 12, wherein the first end of each rim portion is not engaged with the second end of an adjacent rim portion.

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