Wheels for non-motorized vehicles

A wheel for a non-motorized vehicle (e.g., a shopping cart) can include a housing assembly and a tread assembly. The housing assembly can be configured to sealingly house electronics or other components. The tread assembly can removably mate with the housing assembly such that the electronics or other components remain closed and/or sealed within the housing assembly when the tread assembly is mated or unmated with the housing assembly.

BACKGROUND

The present disclosure relates to replaceable treads for wheels and wheels having replaceable treads usable with non-motorized vehicles.

2. Description of the Related Art

Non-motorized wheeled vehicles, such as human-propelled carts (e.g., shopping carts), can include two or more wheels. Vehicle wheels incur wear as a result of use or damage. For example, prolonged use of the wheel can cause a tread of the wheel to become worn down. Accordingly, the wheel may need to be replaced.

SUMMARY

Various embodiments are directed to wheels and wheel treads for non-motorized vehicles (e.g., human-propelled carts). Replacement of vehicle wheels can incur substantial expense, particularly in implementations in which the vehicle wheel includes expensive electronic components (e.g., theft prevention electronics in a shopping cart wheel). Accordingly, in certain embodiments, rather than replacing the entire wheel, the tread of the wheel can be replaced. In certain such embodiments, the tread can be configured to be axially removed and installed on the wheel.

Certain wheels require complete or substantially complete removal and/or disassembly of the wheel from the wheeled vehicle in order to replace the treads of the wheels. Furthermore, some wheels may require the disassembly of a sealed portion of the wheel in order to replace the tread. For example, some embodiments may require the opening of a chamber (e.g., in a central portion of the wheel) in order to replace the tread. However, in certain instances, it can be desirable to avoid disassembling certain portions of the wheel to replace the tread. For example, it can be beneficial to avoid opening a sealed chamber containing electrical components disposed in the wheel.

In some embodiments, a wheel assembly (also called a “wheel” herein) includes a serviceable tread assembly that is capable of being installed and attached to a non-serviceable housing assembly. As used herein, the term “serviceable” has its ordinary meaning and includes, without limitation, the characteristic of being intended to be replaced during the course of use of the item. As used herein, the term “non-serviceable” has its ordinary meaning and includes, without limitation, the characteristic of not intended to be replaced during the intended course of use of the item. For example, certain components of the wheel may be sealed (e.g., to inhibit contamination) and may be non-serviceable. Non-serviceable also includes situations where a component is not intended to be serviced by an end-user but which may be serviced by a factory-authorized technician or by the manufacturer. In certain instances, the wheel assembly is configured for use on a non-motorized vehicle. For example, the wheel assembly can be configured for use on a locking shopping cart wheel. In some embodiments, the tread assembly attaches to the housing assembly with one or more fastening devices (such as screws, bolts, nails, or otherwise) and/or locking features. In certain configurations, the fastening devices and/or locking features are arranged around the circumference of the tread assembly and/or the housing assembly.

Various embodiments include any one, or any combination of, the following features. In some embodiments, the tread assembly includes a tread and a frame (e.g., support, backbone, lattice, skeleton, spine, or other structural portion). In certain instances, the frame provides support and/or reinforcement for the tread. For example, in certain variants, the frame can be positioned radially inward of the tread and can be configured to bear force (e.g., compressive force) that is applied to the tread. In some implementations, the frame is configured to shape the tread (e.g., a generally cylindrical shape). In certain embodiments, the tread assembly couples with the housing assembly, which can include a hub and a cover. In some embodiments, installation of the tread assembly is facilitated by the structure of the hub and cover components. For example, the hub and cover components can be configured to allow the tread assembly to be slid onto the hub.

The wheel assembly can have any one, or any combination of, the following features. In certain embodiments, the tread assembly is held in position on the housing assembly by one or more fastening devices and/or locking features. In some cases, the fastening devices and/or locking features are integral with the tread assembly and/or the housing assembly. In certain embodiments, the fastening devices and/or locking features are axially arranged around the inside and/or outside surfaces of the tread assembly and correspond to mating features similarly arranged around the outer circumferential surfaces of the wheel assembly (e.g., the hub). As used herein, the term “axial,” or derivations thereof, has its ordinary meaning and refers to, without limitation, a direction that is substantially perpendicular to a plane in which the wheel rotates. The axial direction may be substantially parallel to or substantially collinear with a rotation axis of the wheel (e.g., within ten to twenty degrees of the rotation axis). In some cases, the tread assembly is maintained on the housing assembly by one or more fasteners.

Certain embodiments include any one, or any combination of, the following features. In some embodiments, the tread assembly is configured to be removed from the housing assembly. In certain such cases, the tread assembly can be removed without the need to disassemble the housing assembly (e.g., by separating the hub and the cover). Such a configuration can, for example, facilitate easy replacement of the tread assembly (e.g., due to wear or damage) while preserving the integrity of the housing assembly. For example, a tread assembly that can be replaced without the need to open the housing assembly can maintain the efficiency of the seals on embodiments of the housing assembly that include such seals to protect components (e.g., electronics) located inside the housing assembly. In certain instances, removal of the worn or damaged tread is accomplished by the removal or disengagement of the fastening devices and/or locking features that secure the tread to the housing assembly. In some cases, the removal also includes axially sliding the tread off the mating wheel hub exterior geometry. A new tread assembly can be installed by reversing this procedure.

A wheel for a human-propelled cart can comprise a housing assembly having a hub and a cover. The hub can have an inner cavity and can comprise a frame engaging surface having a first mating feature, the inner cavity configured to receive an electrical component and the cover configured to be sealed with the hub, thereby inhibiting access into the inner cavity. In some embodiments, the wheel includes a tread assembly configured to axially receive a portion of the housing assembly, the tread assembly comprising a frame and a tread. The frame can have a tread engaging surface and a hub engaging surface, the hub engaging surface having a second mating feature and being configured to releasably couple with the frame engaging surface of the hub. The tread can be disposed radially outward of the frame and can be configured to engage a surface on which the wheel is configured to roll. The wheel can include a fastener configured to engage the first mating feature and the second mating feature. According to some variants, the tread assembly is configured to removably couple with the housing assembly such that the tread assembly can be axially separated from the housing assembly without unsealing the cover and the hub, thereby facilitating repair or replacement of the tread assembly while maintaining the seal of the cover and the hub. In some embodiments, when the hub engaging surface of the frame is coupled with the frame engaging surface of the hub, the first mating feature and the second mating feature are circumferentially aligned such that the fastener can axially engage the first mating feature and the second mating feature.

The wheel can include any one, or any combination of, the following features. In some embodiments, at least one of the first mating feature and the second mating feature comprises a radially outwardly-extending flange. The tread assembly can include a frame alignment feature comprising a first tread recess configured to receive the first mating feature. The housing assembly may include a hub alignment feature comprising a first housing recess configured to receive the second mating feature. In some embodiments, the wheel is configured to rotate around a rotation axis, and the hub is configured to be rotated relative to the frame about the rotation axis of the wheel. The frame alignment feature can include a second tread recess oriented substantially perpendicular to and extending generally circumferentially from the first tread recess, the second tread recess being configured to receive the first mating feature when the hub is rotated relative to the frame. The frame alignment feature can include a third tread recess extending in a direction generally axially away from the second mating feature, the third tread recess configured to receive the first mating feature when the hub is rotated relative to the frame such that the first mating feature is generally aligned with the third tread recess. In some embodiments, the hub alignment feature includes a second housing recess generally perpendicular to and extending generally tangentially from the first housing recess, the second housing recess configured to receive the second mating feature when the hub is rotated relative to the frame. The hub alignment feature includes a third housing recess extending in a direction generally axially away from the first mating feature, the third housing recess configured to receive the second mating feature when the hub is rotated relative to the frame such that the second mating feature is generally aligned with the third housing recess.

Certain embodiments include any one, or any combination of, the following features. In some embodiments, the tread assembly comprises a first rotational axis and the housing assembly comprises a second rotational axis, the first rotational axis and the second rotational axis being generally collinear when the housing assembly and tread assembly are coupled. The tread can have a tread width, the first mating feature and the second mating feature each can have an axial width that is less than the tread width, and the sum of the axial widths of the first mating feature and the second mating feature can be about equal to the tread width. In some embodiments, the human-propelled cart is a shopping cart.

A method of assembling a shopping cart wheel can comprise forming a housing assembly. Forming the housing assembly can include providing a hub having a central cavity, the hub comprising a first mating feature, axially joining a cover with the hub, the cover configured to form a seal between the cover and the hub, thereby inhibiting access by contaminants into the cavity, forming a tread assembly, wherein forming the tread assembly comprises, providing an annular frame comprising an inner surface and outer surface, the inner surface and the outer surface each comprising recesses, the inner surface further comprising a second mating feature, disposing a tread around at least the outer surface of the frame, and engaging the tread with the recesses on the inner surface and the outer surface of the frame, thereby securing the tread with the frame. In some embodiments, the method of assembling a shopping cart wheel includes aligning the first mating feature of the hub with the second mating feature of the frame, receiving the housing assembly into the tread assembly, and securing the housing assembly with the tread assembly.

Various embodiments have any one, or any combination of, the following. In some embodiments, securing the housing assembly with the tread assembly comprises positioning the first mating feature in a first recess of the frame, wherein the first mating feature comprises a radially outwardly extending flange, positioning the second mating feature in a second recess of the hub, wherein the second mating feature comprises a radially inwardly extending flange, and axially inserting a fastener through the first mating feature and the second mating feature. In some embodiments, the method of assembling a shopping cart wheel further comprises rotating the housing assembly and the tread assembly relative to each other after the housing assembly has been received into the tread assembly. The method of assembling a shopping cart wheel can further comprise axially spacing the first mating feature apart from the second mating feature.

A method of repairing a wheel of a shopping cart, the wheel comprising a housing assembly and a tread assembly coupled with a plurality of fasteners located generally around an outer circumferential region of the wheel, the housing assembly coupled with the shopping cart via a caster assembly, the housing assembly comprising a central sealed chamber that includes an electrical component, can comprise removing the wheel from the caster assembly. In some embodiments the method of repairing a wheel of a shopping cart includes loosening the fasteners such that the housing assembly and the tread assembly can be separated, separating the tread axially from the housing assembly without opening the central sealed chamber of the housing assembly, aligning first flanges of a replacement tread assembly with first recesses of the housing assembly, aligning second recesses of the replacement tread assembly with second flanges of the housing assembly, axially sliding the replacement tread assembly onto the housing assembly, securing the fasteners such that the fasteners couple the replacement tread assembly and the housing assembly, and coupling the housing with the caster assembly.

The method can include any one, or any combination of, the following. In some embodiments, loosening the fasteners comprises rotating the fasteners. The method of repairing a wheel of a shopping cart can further comprise rotating the tread assembly relative to the housing assembly after the replacement tread assembly has been axially slid onto the housing assembly. In some embodiments, the method of repairing a wheel of a shopping cart further comprising radially engaging the first flanges of a replacement tread assembly with the first recesses of the housing assembly, and radially engaging the second recesses of the replacement tread assembly with the second flanges of the housing assembly, thereby providing areas of radial interference between the housing assembly and the tread assembly.

In some embodiments, a wheel for a human-propelled cart includes a hub and a tread assembly. The hub can have a frame engaging surface having a first mating feature, such as a radially outwardly-extending flange. In some embodiments, the flange has a radially distal portion and a radially proximal portion. The radially distal portion can have a first circumferential width and the radially proximal portion can have a second circumferential width. In some variants, the first circumferential width is greater than the second circumferential width. In other variants, the first circumferential width is less than the second circumferential width.

The wheel can include any one, or any combination of, the following features. The tread assembly can be configured to axially receive a portion of the hub. In some implementations, the tread assembly has a frame and a tread. The frame can include a tread engaging surface and a hub engaging surface. The hub engaging surface can have a second mating feature. The second mating feature can include portions (e.g., recesses) shaped to correspond with the flange of the first mating feature. The second mating feature can be configured to releasably couple with the frame engaging surface of the hub. The tread can be disposed radially outward of the frame. The tread can be configured to engage a surface on which the wheel is configured to roll.

Various embodiments include any one, or any combination of, the following features. In some embodiments, when the hub engaging surface of the frame is coupled with the frame engaging surface of the hub, the first mating feature and the second mating feature are circumferentially aligned. For example, in certain such embodiments, a fastener can axially engage the first mating feature and the second mating feature.

In some embodiments, the wheel includes any one, or any combination of, the following features. Certain embodiments include a sealed inner cavity located in the hub with an electrical component located in the cavity. In some embodiments, the hub engaging surface of the frame further includes a radially inwardly-extending flange, and/or the hub further includes a radially inwardly-extending recess configured to receive the radially inwardly-extending flange. In some embodiments, at least one of the radially outwardly-extending flange of the hub and the radially inwardly-extending flange of the frame has a substantially frustoconical cross-sectional shape. In certain embodiments, the radially outwardly-extending flange of the hub and the radially inwardly-extending flange of the frame each have a substantially frustoconical cross-sectional shape. In some embodiments, the frame further comprises a radially extending spacer portion connecting a radially inward facing portion and a radially outward facing portion. The spacer portion can have an axial thickness in a direction substantially parallel to the axis of rotation of the tread assembly. The axial thickness of the spacer portion can be less than an axial thickness of the radially outward facing portion of the frame and/or less than an axial thickness of the radially inward facing portion of the frame. Some embodiments include a plurality of fasteners. Each of the plurality of fasteners can be configured to engage from a first axial side of the wheel. In various embodiments, the electrical component can comprise one or more of: a controller, a processor, a brake, a power source (e.g., a battery), and a transceiver for wireless RF communication (e.g., at a frequency of at least approximately 2.4 GHz, at least approximately 800 Mhz and/or less than or equal to approximately 900 mhz, or otherwise).

According to certain embodiments, a wheel for a human-propelled cart includes a hub and a tread assembly. The hub can have an inner cavity. The inner cavity can be configured to receive an electrical component. The hub can include a frame engaging surface having a first mating feature. The tread assembly can be configured to axially receive a portion of the hub. The tread assembly can have a generally circular shape and an axis of rotation.

The wheel can have any one, or any combination of, the following features. The tread assembly can include an annular tread and a frame. The annular tread can be configured to engage a surface on which the wheel is configured to roll. The frame can be configured to engage with the annular tread. The frame can include a radially outward portion, radially inward portion, and/or radially-extending spacer portion. The radially outward portion can be configured to be received in the annular tread. The radially inward portion can have a hub engaging surface. The hub engaging surface can have a second mating feature. The hub engaging surface can be configured to releasably couple with the frame engaging surface of the hub. The radially-extending spacer portion can connect the radially inward portion and the radially outward portion. The spacer portion can have an axial thickness in a direction substantially parallel to the axis of rotation of the tread assembly. The axial thickness of the spacer portion can be less than an axial thickness of the radially outward portion of the frame and less than an axial thickness of the radially inward portion of the frame.

In various embodiments, the wheel includes any one, or any combination of, the following features. The frame can include one or more tread securement features that are configured to inhibit axial movement of the frame relative to the hub. The one or more tread securement features can include a locking flange. The locking flange can be adapted to engage a frame engagement feature of the hub when the hub is received in the tread assembly. This can inhibit movement of the hub relative to the frame in a direction substantially parallel to the axis of rotation of the tread assembly. The one or more tread securement features can include a radially-deflectable portion connected to the locking portion and to the radially inward portion of the frame. The radially-deflectable portion can include a frangible region. The frangible region can include a notch. Some embodiments include a plurality of fasteners. Each of the plurality of fasteners can be configured to engage from a first axial side of the wheel.

In some embodiments, a kit of parts for replacing wheels on a human-propelled cart includes an annular first tread assembly and an annular second tread assembly. The annular first tread assembly can include a first frame having a first inside surface and a first tread. The first tread can be engaged with and positioned radially outward of the first frame. The first tread can have a first outside surface. The annular second tread assembly can include a second frame having a second inside surface, second tread, and a spacer portion. The second tread can be engaged with and positioned radially outward of the second frame. The second tread can have a second outside surface. The spacer portion can extend radially between the second inside surface and the second outside surface. The first inside surface of the first frame can have a diameter that is substantially equal to a diameter of the second inside surface of the second frame. The first inside surface of the first frame and the second inside surface of the second frame can each be configured to receive and releasably engage with a common wheel hub assembly. The first outside surface of the first frame can have a diameter that is less than a diameter of the second outside surface of the second frame.

Some embodiments of the kit include any one, or any combination of, the following features. In various embodiments, the kit includes the wheel hub assembly. In some embodiments, the wheel hub assembly includes an inner chamber. In certain embodiments, the kit includes an electronic component positioned in the inner chamber. In some embodiments, the kit includes a cover that seals the electronic component from the ambient environment. In certain embodiments, the seal remains intact (e.g., the cover is not unsealed) during releasable engagement of the first frame with the wheel hub assembly and/or during releasable engagement of the second frame with the wheel hub assembly. In some embodiments, the electronic component comprises a brake mechanism, controller (e.g., processor and memory), transceiver, power supply (e.g., battery) or otherwise. The transceiver can be configured to transmit and/or receive radio frequency (RF) signals, such as signals at a frequency of at least approximately 2.4 GHz, at or between approximately 800 Mhz and approximately 900 Mhz, or otherwise.

The kit can include any one, or any combination of, the following features. According to some embodiments, a method of manufacturing a shopping cart wheel includes obtaining a hub having a central cavity. The hub can include a first mating feature with a radially distal portion and a radially proximal portion. The radially distal portion can be circumferentially greater than the radially proximal portion. Some variants of the method include obtaining a tread and an annular frame. The frame can include an inner surface and outer surface. At least one of the inner surface and the outer surface can include a plurality of engagement elements, such as recesses. The inner surface can have a second mating feature. Certain implementations of the method include securing the tread with the frame by disposing the tread around at least the outer surface of the frame, and/or engaging the tread with the plurality of engagement elements (e.g., recesses) on at least one of the inner surface and the outer surface of the frame. Some embodiments of the method include securing the frame with the hub by aligning the first mating feature of the hub with the second mating feature of the frame, and/or engaging the first mating feature of the hub with the second mating feature of the frame. In some embodiments, the method includes engaging a plurality of fasteners with the hub and the annular frame from a first axial side of the wheel.

In some embodiments, a method of assembling wheel assemblies for a human-propelled cart includes obtaining a first hub having an inner cavity configured to receive an electrical component. The method can also include obtaining a first tread assembly.

The method can include any one, or any combination of, the following. In some variants, obtaining a first tread assembly includes obtaining a first annular frame with one or more of: an inner radial portion having a first hub engaging surface, an outer radial portion having a tread engaging surface, and a spacing portion. The spacing portion can be positioned radially between and connected to the inner radial portion and the outer radial portion of the first annular frame. The spacing portion can have a radial thickness. In some variants, obtaining a first tread assembly includes engaging a first tread around at least the outer surface of the first annular frame. The first tread can have a first tread diameter. In certain implementations, the method includes receiving the first hub into the first tread assembly. In some embodiments, the method includes securing the first hub to the first tread assembly.

Various embodiments have any one, or any combination of, the following. Certain variants of the method include obtaining a second hub (e.g., a second hub having an outside diameter that is about equal to an outside diameter of the first hub) and obtaining a second tread assembly. In some embodiments, obtaining a second tread assembly includes obtaining a second annular frame having one or more of: an inner radial portion having a second hub engaging surface, an outer radial portion having a tread engaging surface, and a spacing portion. The spacing portion can be positioned radially between and connected to the inner radial portion and the outer radial portion of the second annular frame. The spacing portion can have a radial thickness that is different from the radial thickness of the spacing portion of the first annular frame. In some embodiments, obtaining a second tread assembly includes engaging a second tread around at least the outer surface of the second annular frame. The second tread can have a second tread diameter that is different from the first tread diameter. In some variants, the method includes receiving the second hub into the second tread assembly. In certain embodiments, the method includes securing the second hub to the second tread assembly.

Several embodiments (e.g., certain embodiments of the kit of parts) include any one, or any combination of, the following features. In some embodiments, the first annular frame includes one or more tread securement features. The one or more tread securement features can have a deflection portion and a locking portion. The deflection portion can be connected to the inner radial portion of the first annular frame. The locking portion can be connected to the deflecting portion. The locking portion can be adapted to interfere (e.g., present a physical stop) with a frame engagement feature of the hub when the hub is received within the first tread assembly. This can inhibit movement of the hub relative to the first annular frame in a direction substantially parallel to an axis of rotation of the first tread assembly. In some embodiments, the method includes engaging the locking portion of the one or more tread securement features of the first annular with the frame engagement feature of the hub. Certain embodiments of the method include deflecting the locking portion of the one or more tread securement features away from the frame engagement feature of the hub. In some variants, the method includes breaking (e.g., non-plastically deforming) the deflecting portion of the one or more tread securement features at a frangible point of the deflecting portion when the locking portion of the one or more tread securement features is deflected away from the frame engagement feature of the hub. In various embodiments, the deflecting portion is partially or completely separated from the remainder of the first annular frame. For example, the deflecting portion can detach from the first annular frame.

DETAILED DESCRIPTION

Non-motorized wheeled vehicles are used in a variety of environments including retail environments (e.g., shopping carts), manufacturing or warehouse environments (e.g., merchandise or industrial carts), travel environments (e.g., luggage or baggage carts at an airport or bus station), medical environments (e.g., hospital carts, medical device carts, wheelchairs, baby strollers), and so forth. Non-motorized vehicles are typically human-propelled, e.g., by a human pushing or pulling the vehicle. The present disclosure describes examples of wheels, treads, and methods for assembling wheels or replacing treads that are usable with non-motorized wheeled vehicles. Many of the examples described herein are in the context of wheels for shopping carts (also called shopping trolleys, supermarket trolleys, trolley carts, or otherwise); however, this is illustrative only and is not a limitation.

With reference toFIG. 1, in some embodiments, a wheel assembly can include a tread assembly10and a housing assembly70. The tread assembly10can be configured to mount or otherwise be received at least partly on the housing assembly70. The tread assembly10can be configured to protect and/or space the housing assembly10from a surface on which the wheel assembly rolls. For example, the tread assembly10can protect the housing assembly70from abrasion due to contact with the surface.

With regard toFIGS. 1-5, an embodiment of a tread assembly10is illustrated. In some embodiments, the tread assembly10includes a frame20and a tread60. In some embodiments, the frame20is generally rigid. In some cases, the frame20is made of metal (e.g., steel or aluminum) or a polymer (e.g., nylon). The frame20and/or tread60can include a rotational centerline. In some embodiments, as illustrated inFIG. 2, the rotational centerline L of the frame20is collinear with the rotational centerline of the tread60when the frame20is mated with the tread60.

As shown inFIG. 3, the frame20can be configured to engage with the tread60. The frame20can have one or more recessed features23. For example, in the embodiment illustrated, the frame20can include recessed features23that are arranged in a radial pattern around an outer circumference of the frame20. As will be discussed in further detail below, the recessed features23can engage with corresponding features of the tread, thereby securing the frame20and the tread60.

According to some variants, the frame20includes a hub-engaging surface28located on the radially-inward surface of the frame20. The frame20can include first mating features22. In some embodiments, the first mating features22are located on the hub-engaging surface28. In certain variants, such as is shown inFIGS. 3 and 4, the first mating features22can be one or more radially inwardly-extending flanges24. In some embodiments, first mating features22are configured to allow for the insertion of a corresponding number of fasteners, such as one fastener per first mating feature22. In the illustrated embodiment, the first mating features22are generally equally spaced in a radial pattern around an inner periphery of the frame20. However, other configurations are contemplated and are included in this disclosure.

In some embodiments, the frame20includes indentations25. In certain instances, the indentations25are arranged in a radial pattern around the inner circumference of the frame20. One or more of the indentations25can span the axial (e.g., parallel to the rotational centerline of the frame) width W of the hub-engaging surface28. In some embodiments, one or more of the indentations25are located axially-adjacent to the radially inwardly-extending flanges24. In such embodiments, the first mating features22can comprise a radially inwardly-extending flange24and an indentation25. The radially inwardly-extending flange24and corresponding indentation25can each have an axial width that is less than the axial width W of the hub-engaging surface28.

The tread60, or parts thereof, can be made of most any material, such as rubber, plastic, wood, metal, or otherwise. For example, the tread60can be a thermo-set material. The tread60can be molded onto, injected, fused, welded, or otherwise joined with the frame20. In some cases, the tread60is formed separately from the frame20and then coupled with the frame20. In other cases, the tread60is formed with the frame20. For example, the frame20can be molded during substantially the same operation (e.g., injection molding operation) as the tread60. In certain instances, the tread60covers all exposed outside surfaces of the frame20. In some embodiments, the tread60is injection molded onto the frame20. In certain cases, the tread60is secured with/to the frame20by adhering with the indentation features23.

In some implementations, the tread60engages with recesses26on the frame20. For example, the tread60can extend around a portion of the sidewall of the frame20, such that the tread60is located radially outward of the frame20and a portion of the tread60is engaged with the recess26. In certain variants, the tread60wraps around a portion of the frame20. In certain instances, the tread60is joined with the frame20with an adhesive (e.g., glue or epoxy), thermal or sonic welding, or otherwise. For example, an adhesive can be applied to an outer surface of the frame20and/or an inner surface of the tread60. In some embodiments, the outer surface (e.g., tread-engaging surface) of the frame20and/or an inner surface (e.g., structure-engaging surface) of the tread60can be textured (e.g., dimpled, ribbed, grooved, or otherwise), which can facilitate a connection between the frame20and the tread60.

The tread60can include a traction surface62configured to engage with a floor or other surface when the non-motorized vehicle (e.g., a shopping cart) is moved. The traction surface62can be constructed of the same material as the tread60or from a difference material. In some embodiments, the traction surface62includes friction features (e.g., channels, protrusions, etc.) configured to facilitate grip between the traction surface62and the floor on which it is resting.

With regard toFIGS. 6-9, an embodiment of a housing assembly70is illustrated. As shown, the housing assembly70can include a structural hub80and a cover90. In certain embodiments, the hub80and the cover90can be assembled together. For example, the hub80and cover90can be held together by fasteners50, which can be arranged in a radial pattern around the circumference of the hub80and/or cover90. In some embodiments, the fasteners50engage with radially outwardly-extending flanges84,94on the hub80and cover90respectively. For example, one or more flanges94on the cover90can be aligned with one or more flanges84on the hub80such that a fastener50can be extended through apertures in the aligned flanges84,94. In some embodiments, the flanges94on the cover90are symmetrically distributed about the outer circumference of the cover90. In some such embodiments, the cover90can be attached to the hub80in a plurality of relative rotational orientations. In some embodiments, the flanges94are asymmetrically distributed about the outer circumference of the cover90such that the cover90connects with the hub80in only one relative rotational orientation. In some such embodiments, rotational alignment of some portion of the hub80and/or the contents therein can be consistently aligned with some portion of the cover90. In some embodiments, the hub80and/or cover90can include one or more magnets housed within and/or on the surface of the hub80and/or cover90(e.g., magnets for use with Hall effect sensors to activate the electrical components within or around the housing assembly70).

In some instances, the hub80and/or the cover90include second mating features82. The second mating features82can correspond to the features22on the inside of the frame20of the tread assembly10. The illustrated embodiment includes a plurality of second mating features82arranged in a radial pattern around the outer circumference of the housing assembly70. Other configurations are also contemplated and are part of this disclosure. In some instances, the second mating features82include radially outwardly extending flanges84. In some instances, the second mating features82include radially inwardly extending notches85. In some instances, such as in the illustrated embodiment, the second mating features82include a combination of radially outwardly extending flanges84and radially inwardly extending notches85.

As shown, the housing assembly70can have an axial depth D. In some cases, the second mating features82extend less than the entire axial depth D of the housing assembly70. In other cases, the second mating features82can extend less than the entire axial depth D of the housing assembly70. Such a configuration can, for example, provide an improved connection between the housing assembly70and the tread assembly10when assembled together, as is discussed below. In some implementations, the depth D of the housing70is greater than or equal to the axial width W of the frame20.

In some embodiments, the cover90and the hub80include rib features97and87that form a mating channel structure around the inside circumference of the cover90and the hub80. The rib features97and87can house a seal (e.g., a rubber or polymeric O-ring), which can be configured to inhibit or prevent moisture or other contaminants from entering the inside of the housing assembly70when the hub80is assembled with the cover90. Such a configuration can, for example, protect devices71(e.g., mechanical or electrical components) disposed inside the housing assembly70, such as is schematically shown in FIG.6A. Examples of such devices can include, for example, a brake mechanism, a two-way communication device, a navigation device, a power generator, a computer processor, a battery, combinations of such devices, or otherwise. Examples of some such devices are discussed in the following: U.S. Pat. No. 8,046,160, titled “NAVIGATION SYSTEMS AND METHODS FOR WHEELED OBJECTS”; U.S. Patent Application Publication No. 2006/0244588, filed Mar. 20, 2006, titled “TWO-WAY COMMUNICATION SYSTEM FOR TRACKING LOCATIONS AND STATUSES OF WHEELED VEHICLES”; and U.S. Patent Application Publication No. 2006/0249320, filed Mar. 20, 2006, titled “POWER GENERATION SYSTEMS AND METHODS FOR WHEELED OBJECTS;” the entirety of each of which is hereby incorporated by reference herein.

In certain variants, the cover90and the hub80are configured to be readily separable from each other. For example, in some implementations, the cover90and the hub80are configured to be separable after the fasteners50are removed. Designs including a separable cover90and hub80can, for example, facilitate the ability to service, replace, repair, and/or otherwise attend-to the devices in the housing assembly70. For example, such designs can facilitate installing a new battery in the housing assembly70. Some embodiments have an O-ring or other type of sealing device disposed between, near, or adjacent to the rib features97and87.

In some variants, the cover90and the hub80are substantially permanently joined. For example, in some embodiments, the channel structure can be at least partly filled with an adhesive (not shown) that, in combination with the surfaces formed by rib features97and87, substantially permanently joins the cover90and the hub80. In some embodiments, the adhesive forms a portion of the seal between the cover90and the hub80. Further, in some such embodiments, the adhesive can inhibit or otherwise discourage disassembly of the housing assembly70.

Certain embodiments that have substantially permanently joined cover90and hub80have a longer life expectancy than embodiments in which the cover90and the hub80are readily separable. For example, embodiments in which the cover90and the hub80are substantially permanently joined can include a battery having a greater life expectancy, an internal generator and power storage (such as is described in U.S. Patent Application Publication No. 2006/0249320, incorporated by reference herein), and/or intelligent power management circuits utilizing motion sensors, each of which, alone or in combination, can provide a longer life than embodiments in which the cover90and the hub80are readily separable.

As shown in the exploded views ofFIGS. 9-11, the tread assembly10can be installed on the housing assembly70. For example, the first mating features22of the frame20can be aligned with the second mating features82of the cover80and hub90of the housing assembly70. In certain embodiments, the tread assembly10can be axially slidably mounted on the housing assembly70when the tread assembly10and housing assembly70are moved toward one another in an axial direction AD. In certain such embodiments, the first mating features22can be received in the radially inwardly extending notches85of the housing assembly70, thus providing a circumferential interference, which can inhibit or prevent the tread assembly10from rotating relative to the housing assembly70. In some embodiments, the flanges84are received into the indentations25of the frame20to provide additional or alternative circumferential interference between the housing assembly70and the tread assembly10. The first mating features22and second mating features82can be circumferentially distributed in a symmetric pattern such that the tread assembly10can align with the housing assembly70in a plurality of relative rotational orientations. In some embodiments, the first mating features22and second mating features82are asymmetrically circumferentially distributed such that the tread assembly10and housing assembly70can align in only one relative rotational orientation. In some such embodiments, alignment between certain features (e.g., sensors, mechanical components, electrical components, etc.) within the housing assembly70and certain features of the tread assembly10can be facilitated.

In some embodiments, as illustrated inFIG. 2A, the tread60and/or frame20can include one or more mating identifiers68. The mating identifiers68can facilitate proper orientation of the tread assembly10with respect to the housing assembly70for connecting the tread assembly10to the housing assembly70. For example, mating identifiers68can be located on the side of the tread60that faces the housing assembly70before the tread assembly10is received onto the housing assembly70. In some embodiments, the mating identifiers68correspond to the side of the tread assembly10opposite the inwardly-extending flanges24.

In some embodiments, the tread assembly10is secured with the housing assembly70with fasteners52in order to, for example, reduce the chance of unintentional separation and/or to reduce vibration. In some configurations, the housing assembly70and/or the tread assembly10include indicia to indicate the fasteners52that couple the housing assembly70with the tread assembly10. In certain instances, at least one of the fasteners52is configured to discourage tampering with the wheel assembly. For example, at least one of the fasteners52can have a non-standard screw driving connection (e.g., a tamper-resistant head). The fasteners52can be installed into the tread assembly10and housing assembly along the axial direction AD.

In some embodiments, a method of installing a tread assembly10includes sliding the tread assembly10onto the housing assembly70. In certain instances, the tread assembly10is slid until it is generally fully seated on the housing assembly70(e.g., in contact with a positive stop or other feature to denote proper placement). The hub80can include one or more hub orientation features83, such as one or more protrusions83or recesses. In some such embodiments, the tread60and/or frame20can include one or more tread orientation features27(e.g., protrusions and/or recesses) configured to engage with the one or more hub orientation features83. Engagement between the tread orientation features27and the hub orientation feature83can facilitate alignment between the first mating feature22and the second mating feature82. In some cases, the tread assembly10is axially installed (e.g., by sliding) onto the housing assembly70. In some embodiments, the method includes securing the tread assembly10to corresponding features on the hub80with fasteners52. According to some variants, the tread assembly10can be connected with and disconnected from the housing assembly70without unsealing the housing assembly70(e.g., without removing the cover90from the hub80).

In certain embodiments, the method further includes mounting the wheel assembly with a caster240, for example as shown inFIG. 12. In certain embodiments, the method also includes placing the wheel assembly between end portions242of the caster240; placing a first fastener228(e.g., a bolt) through the end portions242and the wheel assembly; and securing the first fastener228with a second fastener232(e.g., a nut). In certain instances, the method also includes mating at least one flat portion234of an axle243of the wheel assembly with a retaining clip225. In certain such cases, the method also includes inhibiting rotation of the axle234. For example, rotation of the axle234can be inhibited by an interference fit between the “U”-shaped side of the retaining clip225and at least one of the end portions242of the caster240.

In some embodiments, a method of removing a tread assembly10includes substantially the reverse of some of the actions in the above-described method of installing a tread assembly10. For example: separating the wheel assembly from the caster240(e.g., by loosening fastener228,232and removing the fastener228), loosening the fasteners52, and axially sliding the tread assembly10off of the housing assembly70.

In some embodiments, a method of manufacturing a tread assembly10includes forming a frame20and molding a tread60onto the frame20. Some embodiments include vulcanizing the tread60. In some cases, the method includes applying an adhesive to an outer surface of the frame20, which can, for example, improve adherence of the tread60with the frame20.

With regard toFIGS. 13-22, another embodiment of a tread assembly is illustrated. In some embodiments, the tread assembly110includes a frame120and a tread160. Certain embodiments of the frame120are nylon and are injection molded. In some embodiments, the tread160is rubber (e.g., ethylene propylene diene monomer (EPDM)). Certain variants of the tread160can be over-molded onto the insert ring120. As shown inFIG. 14, in the assembled tread110, the tread160can be positioned generally outside and around the frame120. For example, the frame120can be received in the tread160.

As illustrated inFIGS. 14-16, in certain implementations, the tread insert component120has first mating features122arranged in a radial pattern and spaced apart from one another in a circumferential direction DCaround an inside circumference of the frame120. In some variants, the first mating features122correspond to second mating features182located on an outer circumference of a wheel hub180. The second mating features182can be arranged in a radial pattern around the circumference of the hub180. The tread assembly illustrated inFIGS. 13-22includes a wheel cover configured to mate with the hub180that is not shown in the figures. The wheel cover can be configured to mate with the hub180to create a seal between the wheel cover and the hub180. In some embodiments, the first mating features122and second mating features182are asymmetrically circumferentially distributed such that the tread insert component120and hub180can align in only one relative rotational orientation. In some such embodiments, alignment between certain features (e.g., sensors, mechanical components, electrical components, etc.) of the hub180and certain features of the frame120and/or tread160can be facilitated. The first mating features122and second mating features182can, in some embodiments, be circumferentially distributed in a symmetric pattern such that the insert component120can align with the hub180in a plurality of relative rotational orientations.

As shown inFIGS. 17 and 18, in some variants, the first mating features122of the frame120include protrusions124and recesses125. In certain embodiments, the second mating features182of the hub180include recesses185and protrusions184. The first mating features122can be configured and arranged in such a way that the protrusions124can be received in the recesses185on the hub180, thereby allowing the mating engagement of the protrusions124and the recesses185. Similarly, the protrusions184on the hub180can be received in the recesses125on the insert ring120, thereby allowing the mating engagement of the protrusions184and the recesses125.

In certain embodiments, the tread insert160can be assembled with the wheel hub180by mating (e.g., by sliding) the tread insert160onto the hub180. For example, the protrusion124on the insert160can be generally aligned with a portion of the recess185of the hub180, thereby allowing the protrusion124to be slidably received (e.g., axially) in the recess185. In some embodiments, the insert160is pushed onto the hub180. In some embodiments, the tread insert160is pushed completely onto the hub.

In certain variants, the recess185has sufficient axial width (e.g., parallel with the axis of rotation) that the protrusion124does not circumferentially interfere with the protrusion184, when the protrusion124is received in the recess185. In some arrangements, when the protrusion124is received in the recess185, the protrusion124has a first axial width and the protrusion184has a second axial width, with the first and second axial widths not axially overlapping.

As shown inFIGS. 21 and 22, in some implementations, the tread insert160can be rotated relative to the hub180. In some embodiments, the tread insert160can be rotated (e.g., in a clockwise direction relative to the hub) until it engages (e.g., abuts or otherwise is stopped by) walls that define the recess185of the hub180. For example, rotation of the tread insert160relative to the hub180can cause the protrusion124of the insert160to be received into a second recess188extending perpendicular and generally in a circumferential direction DCaway from the recess185. In some configurations, rotation of the tread insert160relative to the hub180can cause the protrusion184of the hub80to be received into the second recess129on the tread insert120. Such a configuration can, for example, increase the strength and/or reduce the likelihood of relative movement of the insert160and hub180. In some embodiments, the engagement of the insert160and the walls of the hub180facilitates torque transfer between the insert160and the hub180. In certain variants, when the tread insert160is rotated, the protrusions124on the inside circumference are moved near, next to, in front of, and/or behind the protrusions184on the outside of the hub180.

In certain implementations, the protrusions124,184include holes111. In certain embodiments, when the tread insert component160has been rotated to its final position, the holes111that pass through each of the protrusions124,184will be aligned. In some implementations, fasteners (e.g., screws52) can be driven into the aligned holes111, thereby securing the tread insert160and hub180and/or inhibiting or preventing further relative rotation of the insert160and hub180. Some variants include a wheel cover with a mating hole (not shown). In some embodiments, the fasteners50,52secure the tread insert160and hub180and wheel cover (not shown). For example, the fasteners50,52can pass through a portion of each of the tread insert160and hub180and wheel cover. Such a configuration can enhance the structural and/or watertight characteristics of the tread assembly. In some embodiments, each of the fasteners50,52passes through the wheel cover. In some embodiments, the fasteners52used to connect the first mating feature122to the second mating feature182can have a non-standard screw driving connection (e.g., a tamper-resistant head).

In some embodiments, the tread insert160can be configured such that the protrusion124can be axially spaced apart from the protrusion184. In some variations, the protrusion124of the tread insert160are received by a generally axially oriented third recess189of the second mating feature182. Such reception of the protrusion124can facilitate torque transfer between the protrusion124and the walls defining the third recess189. In some embodiments, engagement of the protrusion124with the third recess189can reduce stress on any fasteners52used to mate the first mating feature122with the second mating feature182.

FIGS. 23-26illustrate another embodiment of a wheel. The wheel can include a tread assembly310and housing assembly370that can include components or portions that are the same as or similar to the components or portions of the tread assembly10and housing assembly70described above. Some numerical references to components inFIGS. 23-26are the same as or similar to those previously described for the tread assembly10and housing assembly70(e.g., a cover390is similarly numbered as the cover90discussed above).

According to certain embodiments, the tread assembly310includes a frame320and a tread360. As discussed in further detail below, the frame320can be configured to receive and/or engage the tread360. Certain embodiments of the frame320are a metal, such as aluminum, or a plastic, such as nylon. In some implementations, the frame is injection molded. In some embodiments, the tread360is rubber (e.g., ethylene propylene diene monomer (EPDM)). Certain variants of the tread360can be over-molded onto the frame320. As shown inFIG. 23, in the assembled tread310, the tread360can be positioned generally outside and around the frame320. For example, the frame320can be received in the tread360.

In some embodiments, as illustrated inFIG. 23-24the frame320includes one or more mating features. For example, the frame320can include one or more protrusions324. The protrusions324can extend radially-inward (e.g., as measured in the frame of reference of the radius of the frame320) from a radial inner surface of the frame320. The protrusions324can include apertures configured to receive fasteners355(e.g., screws). In some embodiments, the protrusions324have a first portion radially spaced apart from a second portion. For example, the first portion can be located radially inward of the second portion. In some embodiments, the first portion has a circumferential width that is greater than a circumferential width of the second portion (e.g., located radially outward from the first portion).

In some embodiments, the frame320includes one or more recesses325. The recesses325can extend radially-outward from a radially-inward face of the frame320. In some embodiments, a radially-outwardly positioned portion of the recesses325is circumferentially wider than a radially-inwardly positioned portion of the recesses325. For example, the circumferential width of the recesses325at a radially-inward edge can be less than a circumferential width of the recesses325at a point radially-outward from the radially-inward edge of the recesses325.

As illustrated inFIGS. 23 and 25-26, the housing assembly370can include a structural hub380configured to couple with a cover390. For example, one or more fasteners350(e.g., screws) can be used to couple one or more radially-outward extending flanges394of the cover390with one or more radially-outward extending flanges384of the hub380. The flanges384,394can be sized and shaped to couple with the recesses325of the frame320. For example, the flanges384and/or the flanges394can be correspondingly shaped with the recesses325. In certain implementations, the flanges384and/or the flanges394extend radially-outward in a flared shape.

In some embodiments, the circumferential width of the flanges384,394changes as a function of radial distance. For example, the circumferential width of the flanges384,394can increase as a function of radial distance. The flanges384and/or the flanges394can have a radially distal portion and a radially proximal portion. The radially distal portion can have a first circumferential width and the radially proximal portion can have a second circumferential width. In some embodiments, the first circumferential width is larger than the second circumferential width. For example, the ratio of the first circumferential to the second circumferential width can be at least about: 1.05:1, 1.1:1, 1.25:1, 1.33:1, 1.5:1, 1.75:1, values between the aforementioned values, or otherwise.

In some embodiments, a first surface of the flanges384and/or the flanges394is angled with respect to a body portion of the hub380and/or cover390, respectively. For example, the first surface can be angled in the radially-outward direction at an angle A1. In certain variants, the angle A1is greater than or equal to about 3° and/or less than or equal to about 20°. In some embodiments, the angle A1is less than or equal to about: 4°, 6°, 8°, 10°, 15°, 20°, 25°, values between the aforementioned values, or otherwise.

In certain embodiments, a second surface of the flanges384and/or the flanges394is angled with respect to the body portion of the hub380and/or cover390, respectively. For example, the first surface can be angled in the radially-outward direction at an angle A2. According to certain variants, the angle A2is about equal to the angle A1. In some embodiments, the angle A2is greater than the angle A1. In certain implementations, the angle A2is less than the angle A1.

In some embodiments, the structural hub380includes one or more radially-inward recesses385. The recesses385can have first radially-inward portions that have circumferential widths that are greater than the circumferential widths of portions of the recesses385located radially-outward from the first radially-inward portions of the recesses385. In some embodiments, the recesses385are sized and shaped to couple with the protrusions324of the frame320.

In some embodiments, the protrusions324and/or the flanges384,394, in combination with the corresponding mating feature (e.g., the recesses385and325, respectively) can inhibit or prevent relative movement of the tread assembly310with respect to the housing assembly370. As illustrated inFIG. 23, the tread assembly310can be received in the housing assembly370. For example, in some embodiments, some or all of the tread assembly310can be slid generally along an axial direction AD into the housing assembly370. In certain variants, when the tread assembly310is slid onto the housing assembly370, the protrusions324can be received (e.g., slidably) into the recesses385. In some embodiments, when the tread assembly310is slid onto the housing assembly370, the flanges384,394can be received (e.g., slidably) into the recesses325. The protrusions324can interface with the recesses385and/or the flanges384,394can interface with the recesses325to inhibit relative rotation of the tread assembly310with respect to the housing assembly370.

In some embodiments, the varying (e.g., as a function of radial distance) circumferential widths of the protrusions324and recesses385can inhibit or prevent radial movement of the tread assembly310with respect to the housing assembly370. In some embodiments, the varying (e.g., as a function of radial distance) circumferential widths of the flanges384,394and the recesses325can inhibit or prevent radial movement of the tread assembly310with respect to the housing assembly370and/or can help to inhibit or prevent rotational movement of the tread assembly310with respect to the housing assembly370. According to some variants, inhibiting radial and/or rotational movement between the tread assembly310and housing assembly370can reduce wear on the tread310, can decrease vibration, and/or can increase the lifespan of the tread assembly310.

As illustrated inFIG. 23, one or more fasteners355can be used to couple the tread assembly310with the housing assembly370. The fasteners can include a head end, which can be configured to engage with a screwdriver or other tool, and a working end opposite the head end. In some variants, the fasteners355can be inserted through (e.g., by a slip fit) passages in protrusions382of the housing assembly370(seeFIG. 26). In various embodiments, the passages in the protrusions382can extend completely through the protrusions382in the generally axial direction such that the working end of one of the fasteners355can pass completely though one of the passages. The protrusions382can extend radially-outward from the structural hub380.

In some embodiments, one or more of the fasteners355can engage apertures in the protrusions324of the frame320. For example, the working ends of the fasteners can extend through the passages in the protrusions382of the housing assembly370and can engage the protrusions324of the frame320. As the tread assembly310typically is a lower cost component (e.g., does not include certain electronics or other parts) in comparison to the hub assembly370, and/or is a component that is more readily replaceable than the hub assembly370, it can be desirable to position the working end in the tread assembly310. For example, in the event that one or more of the fasteners355were to break or otherwise fail, which can result in the working end being generally irretrievable, it can be desirable to have the generally irretrievable working end positioned in the lower cost and/or more readily replaceable component (e.g., the tread assembly310) than in the hub assembly370. Accordingly, in some embodiments, all of the fasteners355are disposed so that the working ends of the fasteners can engage the protrusions324in the tread assembly310(e.g., in the frame320). In some embodiments, such a configuration can facilitate reuse of the hub assembly370and/or reduce the likelihood of the working end of one or more of the fasteners355being generally irretrievably disposed in the protrusion384, which could require discarding the hub assembly370. In other embodiments, some (or even none) of the fasteners355are disposed so that the working ends of the fasteners can engage the protrusions324in the tread assembly310, while other(s) of the fasteners355are oriented oppositely with their working ends disposed in the hub assembly370.

FIGS. 27-32illustrate another embodiment of a wheel. The wheel can include a tread assembly410and housing assembly470(e.g., hub) that can include components or portions that are the same as or similar to the components or portions of the tread assembly310and housing assembly370described above. Some numerical references to components inFIGS. 27-32are the same as or similar to those previously described for the tread assembly310and housing assembly370(e.g., a frame420is similarly numbered as the frame320discussed above).

As illustrated inFIGS. 27-29, the tread assembly410can include a frame420and a tread460. The tread460can be positioned radially outward from the frame420when the tread assembly410is in an assembled configuration. In some embodiments, the tread460is co-molded onto the frame420. The tread assembly410can be configured to removably mate with the housing assembly470. The housing assembly470can include one or more non-serviceable portions, such as an electronic component (e.g., a controller, battery or other power source, or otherwise).

In some embodiments, it is desirable to use wheels of varying diameters. For example, in certain applications using four wheels (e.g., shopping carts), it may be desirable to have rear wheels that have larger or smaller diameters than the front wheels. However, this can result in a need to inventory, order, maintain, or otherwise handle multiple wheel sizes. It may be more convenient and/or desirable to inventory a single housing assembly470configuration (e.g., size and/or model) that is adapted to mate with different tread sizes.

As described in further detail below, the housing assembly470can engage with a frame420. In some embodiments, the frame420is similar or identical to the frame310. For example, for some variants of the tread460having a first inside diameter, an inside of the frame420can directly mate with an outside of the housing assembly470. In some embodiments, such as embodiments in which the tread460has a second inside diameter (e.g., greater than an outside diameter of the housing assembly470by at least about 5 mm), the frame420is includes an adapter, such as a spacer430or other radial-spacing structure. In some such embodiments, the spacer430can span some or all of the radial gap between the tread460and the housing assembly470. In various implementations, such a design can facilitate use of treads460having different diameters with a single housing assembly470configuration (e.g., size). In several embodiments, the spacer430can facilitate using various tread460sizes with a common housing assembly470. As used herein, the term “common” has its normal and ordinary meaning (e.g., joint; the characteristic of being shared by two or more things; or otherwise). For example, in some embodiments, treads460having different configurations (e.g., outside diameters) are adapted to each receive and/or matingly engage with a common (e.g., the same) housing assembly470.

As illustrated inFIGS. 30-31, the frame420can have an inner radial portion420aincluding one or more mating features (e.g., protrusions424, recesses425, alignment features427, etc.). The inner radial portion420acan be sized and shaped to mate with a single (e.g., a standardized) configuration (e.g., size, model, mating features, etc.) of the housing assembly470. In some embodiments, the inner radial portion and/or mating features of the frame420are radially inwardly spaced from the tread460and/or from an outer radial portion420bof the frame420(e.g., a portion of the frame420configured to engage with the tread460). For example, the frame420can include the spacer430. The spacer430can be positioned between the inner radial portion of the frame420and the outer radial portion420bof the frame420.

As illustrated inFIG. 31, the spacer430can comprise a circumferential wall, or some other similar structure. In some embodiments, the spacer430can include one or more cut-outs, apertures, protrusions, indentations, or other surface features along the circumference of the spacer430. The spacer430can have a radial height436. The radial height436of a spacer430of a particular frame420can be determined by the desired wheel diameter. For example, in some embodiments, the radial height436can be greater than or equal to about 2 mm and/or less than or equal to about 25.4 mm. In some embodiments, the radial height436is greater than or equal to about 3.2 mm and/or less than or equal to about 13.3 mm. In some embodiments, the height436is approximately 5 mm. Many variations are possible.

In some embodiments, the radial thickness436of the spacer430is less than a radial thickness433of the tread460. In some embodiments, the radial thickness436of the spacer430is greater the radial thickness433of the tread460. For example, the radial thickness436of the spacer430can be greater than or equal to about 102% of the radial thickness of the tread460and/or less than or equal to about 240% of the radial thickness of the tread460. In some embodiments, the radial thickness436of the spacer430is at least approximately 185% of the radial thickness of the tread460.

According to certain embodiments, the spacer430can have an axial thickness437(e.g., a thickness parallel to the axial direction AD). The axial thickness437of the spacer430can be less than or equal to an axial thickness438of a radially outward portion of the frame420, such as the outer radial portion420b. For example, the axial thickness437of the spacer430can be greater than or equal to about 5% of the axial thickness438of a radially outward portion of the frame420and/or less than or equal to about 80% of an axial thickness438of a radially outward portion of the frame420. In some embodiments, the axial thickness437of the spacer430is approximately 15% of the axial thickness438of a radially outward portion of the frame420. In some embodiments, a radially inward portion of the frame420has substantially the same axial thickness as the radially outward portion of the frame420. In some embodiments, a frame420having a spacer430that has a smaller axial thickness than the axial thickness of the radially inward and radially outward portions420a,420bof the frame420can reduce material costs and/or facilitate manufacturability (e.g., molding). In some embodiments, an axially thin spacer430can facilitate a light-weight frame420.

As illustrated inFIGS. 27-32, the spacer430can include one or more stabilizing elements (e.g., ribs435). The stabilizing elements can increase the strength and/or rigidity of the frame420. This can inhibit or prevent relative movement and/or wobble (e.g., rotation about an axis other than the rotational axis of the wheel) between the tread460and the housing assembly470when the tread assembly410is installed on the housing assembly470. For example, an axial rib435can be positioned radially outward from one or more of the protrusions424of the frame420. In some embodiments, an axial rib435extends radially outward from each of the protrusions425. Some or all of the axial ribs435can have an axial thickness that is less than or equal to the axial thickness438of the radially outward portion420bof the frame420. For example, the axial thickness of the axial ribs435can be greater than or equal to about 50% of the axial thickness438of the radially outward portion420bof the frame420and/or less than or equal to about 95% of the axial thickness438of the radially outward portion420bof the frame420. In some examples, the axial rib435has an axial thickness of at least approximately 95% of the axial thickness438of the radially outward portion of the frame420.

As illustrated inFIG. 32, a radial distance between a radial inward surface of the protrusion424and the tread portion460can be greater than a radial thickness433of the tread portion460. For example, the radial distance between a radial inward surface of the protrusion424and the tread portion460can be greater than or equal to about 125% of the radial thickness433of the tread portion460and/or less than or equal to about 300% of the radial thickness433of the tread portion460. In some embodiments, the radial thickness between an inner radial surface of the protrusion424and the tread460is at least approximately 215% of the radial thickness433of the tread460.

FIGS. 33-39illustrate another embodiment of a wheel. The wheel can include a tread assembly510and housing assembly570(e.g., hub) that can include components or portions that are the same as or similar to the components or portions of the tread assembly410and housing assembly470described above. Some numerical references to components inFIGS. 33-39are the same as or similar to those previously described for the tread assembly410and housing assembly470(e.g., a frame520is similarly numbered as the frame420discussed above).

As illustrated inFIGS. 34-37, the frame520can include one or more tread securement features541. The tread securement features541can be, for example, locking flanges or other structure configured to inhibit axial and/or circumferential movement between the frame520and the housing assembly570when the frame520is connected to (e.g., engaged with) the housing assembly570.

The tread securement features541can include a locking portion543. In some embodiments, the locking portion543is a tooth, protrusion, or other surface feature configured to engage with a portion of the housing assembly570. As discussed in further detail below, the locking portion543can engage a portion of the housing assembly570to facilitate securing of the tread assembly510and the housing assembly570.

The tread securement features541can include a deflection portion545. For example, a deflection portion545of the tread securement features541can permit deflection of the locking portion543during engagement and/or during disengagement of the locking portion543with a portion of the housing assembly570. In some embodiments, the deflection portion545can be constructed from a flexible and/or semi-flexible material (e.g., a polymer or metal). In various embodiments, the deflection portion545is configured to resiliently deflect in a generally radial direction, such as radially outwardly. As discussed in further detail below, in some embodiments, the deflection portion545can be configured to resiliently deflect with certain amounts of deflection (e.g., less than or equal to about: 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, values between the aforementioned values, and otherwise) and to non-resiliently deflect with certain other amounts of deflection (e.g. greater than the amount of resilient deflection).

As illustrated inFIGS. 38 and 39, the housing assembly570can include one or more frame engagement features547. For example, the housing assembly570can include one or more indentations, grooves, protrusions or other surface features which can engage (e.g. releasably or permanently) with a portion of the tread securement features541of the frame520. In some embodiments, the frame engagement features547are configured to receive the locking portions543of the tread securement features541.

In some embodiments, the housing assembly570and/or cover590include one or more assembly facilitating features, such as indentations549. The indentations549can be sized and shaped to engage with the locking portion543of the tread securement features541of the frame520. For example, the indentations549can have a sloped surface configured to radially deflect (e.g., radially outward) the locking portion543of the tread securement features541as the locking features are transitioned to an engaged position with the frame engagement features547along the axial direction AD. In various embodiments, the assembly facilitating features are generally circumferentially aligned with the frame engagement features547. For example, as illustrated inFIG. 38, the indentations549and the frame engagement features547are generally circumferentially aligned. In some implementations, the indentations549are on one axial side of the housing assembly570and the frame engagement features547are on the axially opposite side of the housing assembly570. In some embodiments, the indentations549and the frame engagement features547are connected by a channel (not shown).

During assembly of the tread assembly510with the housing assembly570, the tread securement features541can be circumferentially aligned with the indentations549. The tread assembly510can be moved axially relative to the housing assembly570. This can engage the securement features541with the indentations549, which can result in the securement features541being deflected (e.g., radially outwardly) by the slope of the indentations549. The tread assembly510can travel axially over the housing assembly570. With continued axial movement, the locking portion543of the tread securement features541can engage (e.g., deflect into) the frame engagement features547on the housing assembly570, as shown inFIG. 39. This can secure the tread assembly510with the housing assembly570.

As illustrated inFIG. 39, the locking portions543of the tread securement features541can engage with the frame engagement features547of the housing assembly570. As noted above, this can secure the tread assembly510with the housing assembly570. However, some embodiments are configured to facilitate removal of the tread assembly510from the housing assembly570, such as when the tread560has become worn or damaged. For example, in certain implementations, a tool (e.g., a screwdriver or other similar tool) can be used to deflect the locking portion543of a tread securement feature541of the frame520away (e.g., radially outward) from the axial locking feature547of the housing assembly570. Certain implementations are configured such that a portion of the tool can be used as a lever or wedge, such as between the locking portion543and the tread securement feature541. This can facilitate disengagement of the locking portion543from the frame engagement feature547, thereby allowing the tread assembly510to be axially removed from the housing assembly570.

Some embodiments include a plurality of locking portions547and a plurality of frame engagement features547. In certain such embodiments, all of the locking portions543will need to be disengaged from the frame engagement features547for the tread assembly510to be axially removed from the housing assembly570. This can provide additional security, because even if one or more of the locking portions543are inadvertently disengaged from the frame engagement features547, the tread assembly510can remain secured to the housing assembly570.

In some embodiments, some portion of the tread securement feature541, such as the deflection portion545, can include one or more features configured to form a weakened or frangible region on the tread securement feature541. For example, the deflection portion545can include one or more indentations, notches, or other surface features. In some variants, the frangible portion (e.g., a notch, slot, portion of narrowed material thickness, portion of decreased material strength, or otherwise) can be positioned on the deflection portion545. The frangible portion can to permit a user to break (e.g., non-resiliently deflect) the axial engagement portion541during removal of the tread assembly510from the housing assembly570. For example, the frangible portion can be configured to break upon deflection of the locking portion543beyond a certain extent in a radially outward direction (e.g., with a tool, such as a screwdriver). In various embodiments, the frangible portion is adapted to break when the locking portion543has been deflected at least about: 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, values in between the aforementioned values, or otherwise.

The ability to break tread securement features541(e.g., with the frangible portion) can, for example, reduce the likelihood of the locking portion543resiliently deflecting back into engagement with the indentation549. This can facilitate removal of the tread assembly510from the housing assembly570. In some embodiments, breaking the tread securement features541can provide confirmation that the tread assembly510has been used. Such confirmation can reduce the likelihood that a user inadvertently reinstalls a used tread assembly510onto a housing assembly570.

Although the present disclosure has been described in terms of certain preferred embodiments and certain preferred uses, other embodiments and other uses that are apparent to those of ordinary skill in the art, including embodiments and uses which do not provide all of the features and advantages set forth herein, are also within the scope of the present disclosure. Components, elements, features, acts, or steps can be arranged or performed differently than described and components, elements, features, acts, or steps can be combined, merged, added, or left out in various embodiments. For example, any or all of the features of the tread assembly ofFIGS. 1-12can be used with the tread assembly ofFIGS. 13-22and/orFIGS. 23-26, and any or all of the features of the tread assembly ofFIGS. 13-22and/orFIGS. 23-26can be used with the tread assembly ofFIGS. 1-12. Also, the wheels and tread assemblies shown and described herein can be used on any type of non-motorized wheeled vehicle, human-propelled vehicle, or cart such as a shopping cart, a hospital or medical device cart, wheelchair, an equipment cart, and so forth. Indeed, all possible combinations and subcombinations of elements and components described herein are intended to be included in this disclosure. No single feature or group of features is necessary or indispensable for every embodiment. Accordingly, the scope of certain embodiments of the present disclosure is to be defined by the claims that follow and their obvious modifications and equivalents.

Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than or equal to 10% of, within less than or equal to 5% of, within less than or equal to 1% of, within less than or equal to 0.1% of, and within less than or equal to 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, 0.1 degree, or otherwise. As yet another example, in certain embodiments, the terms “generally perpendicular” and “substantially perpendicular” refer to a value, amount, or characteristic that departs from exactly perpendicular by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, 0.1 degree, or otherwise.

In summary, various embodiments and examples of wheel assemblies and methods have been disclosed. Although the wheel assemblies and methods have been disclosed in the context of those embodiments and examples, it will be understood by those skilled in the art that this disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and/or other uses of the embodiments, as well as to certain modifications and equivalents thereof. For example, while some embodiments have been described in connection with shopping carts, some embodiments can be configured to be used with other types of non-motorized wheeled vehicles. This disclosure expressly contemplates that any of the various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another. Accordingly, the scope of this disclosure should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.