The invention provides a caster comprising a bracket, a first transmission device and two wheels. The two wheels are connected by a transmission screw and are fixed to the bracket. The first transmission device comprises an annular retaining portion and a plurality of first balls, the plurality of first balls are equiangularly arranged in a circumferential direction of the annular retaining portion, and opposite sides of the annular retaining portion are respectively embedded in the respective wheels. The caster of the invention can solve the problems in the prior art that it is difficult to control the gap between the two wheels, the resistance generated between the two wheels is large and noise is easily generated.

A system including a frame and a pair wheel of assemblies to engage with one or more tracks of a structure. The pair of wheel assemblies include a first hub assembly, having a first wheel and a first attachment mechanism to engage with the one or more tracks of the structure, and a second hub assembly having a second wheel and a second attachment mechanism to engage with the one or more tracks of the structure. The system further includes an elongated rod coupling the first hub assembly to the second hub assembly, where a movement of the elongated rod causes the first attachment mechanism and the second attachment mechanism to engage with the one or more tracks of the structure.

A spacing bar of a wheelchair frame comprising an elongated structural body having a pair of opposite ends, each of the opposite ends having a C-shaped clamp configured for being clamped to respective lateral frame members of the wheelchair frame, wherein the elongated structural body and the C-shaped clamps are integrally made of a monocoque composite construction, and a tightening assembly for each of the C-shaped clamps, the tightening assemblies being arranged in the spacing bar to loosen and tighten the C-shaped clamps to the respective lateral frame members. A wheelchair frame comprising: a pair of lateral frame members configured to support at least a seat, and front and rear wheel units, the lateral frame members each having an elongated frame portion in a seating zone of the wheelchair frame, and a spacing bar having an elongated structural body and a pair of opposite ends, each of the opposite ends having a connector configured for being clamped to a respective one of the lateral frame member of the wheelchair frame, wherein each of the connectors forms a joint with the respective one of the elongated frame portions constraining the spacing bar to movement of the spacing bar axially along the pair of the elongated frame portion, a tightening assembly for each of the connectors, the tightening assemblies being arranged in the spacing bar to loosen and tighten the connectors to block or allow movement of the spacing bar along the pair of the lateral frame members.

Embodiments of the present application disclose a universal wheel assembly and a smart cleaning device having the same. The universal wheel assembly includes a rotating shaft support and a universal wheel support. The rotating shaft support is configured to be fixed to a predetermined mounting position. The universal wheel support is connected to the rotating shaft support and is rotatable relative to the rotating shaft support. The universal wheel support is provided with a through hole, and the through hole is used for a mounting tool to pass through to fix the rotating shaft support to the predetermined mounting position.

A work vehicle includes a pair of left and right pivotal connecting units provided on a front frame, a caster wheel, a caster axle and a caster bracket connected to the pivotal connecting unit. The caster bracket includes side walls supporting the caster axle, a top wall extending rearwards from the upper side of the caster wheel and interconnecting the left side wall and the right side wall, and left and right cover portions for covering gaps between the side walls and the caster wheel.

A wheel adapter for connecting to a cargo container and providing the cargo container with rolling mobility. The wheel adapter includes an adapter body, one or more wheels rotatable with respect to the adapter body, and a container connector extending from the adapter body for connection to the cargo container. A pusher mechanism engages the adapter body and can be operated to move the adapter body relative to the wheel or wheels in order to vary the vertical placement of the wheel(s) in relation to the container connector. For example, the pusher mechanism can include a wheel-displacement bolt for translationally moving the wheel(s) upward and downward with respect to the container connector, and/or an airbag unit for pivoting the adapter body in relation to the wheel(s) and thus lowering or raising the wheel(s) with respect to the container connector.

A wheelchair can comprise: a frame comprising an upper portion and a lower portion that is coupled to the upper portion so that the upper portion is vertically adjustable with respect to the lower portion. A pair of drive wheels can be coupled to the frame. A plurality (e.g., a pair) of casters are coupled to the frame. Each caster can have a respective swivel axis. At least one caster of the plurality of casters can be configured to be locked to prevent swiveling about its respective swivel axis and unlocked to enable swiveling about its respective swivel axis.

A wheel assembly has a wheel with a hub. A rotation surface disposed in the hub has a bore. A sleeve insertable in the bore of the rotation surface has an outer surface with a circumferential groove and first and second opposite axial ends. The first axial end has a shoulder extending radially outward. A resilient ring disposed in the circumferential groove is compressible to a compression diameter sufficient to enable the sleeve to be inserted in the bore of the rotation surface. The resilient ring is expandable to an expansion diameter greater than the inner surface diameter of the bore of the rotation surface when unconstrained. The circumferential groove is spaced from the shoulder at a distance sufficient to enable the resilient ring to expand to the expansion diameter when the sleeve is inserted in the bore of the rotation surface and the shoulder is adjacent the rotation surface.

A system of bracket assemblies for a wheelchair comprises a pair of bracket assemblies adapted to be connected to respective sides of a seat frame of the wheelchair. Each of the bracket assemblies has a base adapted to be secured to a seat frame member of the seat frame, an arm adapted to be secured to a backrest frame member of a backrest frame, and a pivot pivotally connecting the base to the arm for rotational movement of the arm relative to the base. One or more blocking mechanism blocks the rotational movement of the arm relative to the base in a use orientation of the backrest frame. A rod having opposed ends connected to the base of the pair of the bracket assemblies for spacing the bracket assemblies away from one another. A rear wheel unit is also provided.

A tube assembly for a wheelchair frame comprises a tubular member having at least a first portion and a second portion angled relative to the first portion, the first portion configured to be in a seating zone of the wheelchair frame. The second portion is configured to be in a bottom front zone of the wheelchair frame, the tubular member defining a surface concavity in its peripheral surface delimited by a peripheral step, the surface concavity located at a junction between the first portion and the second portion of the tubular member. An interface member has a peripheral contour shaped and sized for the interface member to be received in the surface concavity and contoured at least partially by the peripheral step.