A load carrying device comprises a load carrying portion, a roller and an inflation arrangement in connection with the roller for selectively inflating the roller from a deflated state to an inflated state and for selectively deflating the roller from the inflated state to the deflated state, the roller rotatable to allow movement of the load carrying device, the roller comprising: an attachment arrangement attaching the roller to the load carrying portion so that the roller provides support to the load carrying portion; and a body for contacting a surface on which the load carrying device is located.

A compressor assembly (10) for supplying pressure medium to a tire cavity (7) of a tire of a vehicle wheel, which can be mounted on a wheel hub (4) that is mounted on a wheel carrier (3) for rotation about an axis of rotation (32). The compressor assembly (10) includes a hub-side compression chamber (16) and a compressor component (18). A pressure medium is conducted into the tire cavity (7) upon being pressurized in the compression chamber (16) by oscillating translational motion of the compressor component (18). The compressor assembly (10) includes a transmission (20) that converts a rotational motion between the wheel carrier side and the wheel hub side into an oscillating translational motion of the compressor component (18) when a hub-side transmission part (24) is in an operating position with a wheel-carrier-side transmission part (26).

The invention relates to a method of estimating the load on a motor vehicle (10). The motor vehicle (10) having a wheel (12) comprising a tread (20) for rolling over a surface being driven on (14) and a first air chamber (32) in which there is a gas which by means of its gas pressure (G) counteracts de-formation of the tread (20) when the wheel (12) is rolling. The method lets gas into the first air chamber 32 over a predetermined period and estimates the load based on the change in pressure in the chamber. The object under-lying the invention is to provide a means of estimating the load on a vehicle. For this purpose the wheel (12) may have a second air chamber (38) coupled to the first air chamber (32) by a valve device (44), the first air chamber (32) extending between the tread (20) and the second air chamber (38) and the gas may flow from the second air chamber (38) into the first air chamber (32).

The invention relates to a compressor assembly for supplying pressure medium to a tire cavity of a vehicle wheel that can be mounted on a wheel hub which can be mounted on a wheel carrier so as to be rotatable about an axis of rotation. The compressor assembly includes a wheel mount-side transmission component including a cylindrical cam.

A multi-chambered wheel assembly may include a wheel rim and a tire mounted on the wheel rim. The tire and the wheel rim may define an interior chamber. A divider wall may be disposed in the interior chamber. The divider wall may define a fill chamber and a gas cavity. A gas valve may be communicated with the gas cavity. The gas valve may be configured to allow pressurized gas to be introduced into the gas cavity. A fill valve may be communicated with the fill chamber. The fill valve may be configured to allow fill material to be introduced into the fill chamber.

A rapid inflation system is provided for the tires of a machine such as an agricultural machine which must periodically move between field conditions and road conditions. The system can relatively rapidly inflate the tires from a lower field ready state to a higher pressure road ready state by the use of a high pressure reservoir chamber defined within the tire.

A device for maintaining and changing the pressure in a is provided whereby the inner pressure space of the tire is connected through a pump to a pressure accumulator which, at its input and/or output into the inner pressure space of the tire, is fitted with at least one pressure control element. The pump can be a peristaltic pump in the shape of a deformable hose placed on the perimeter of the tire, fitted with an air inlet and an air outlet, while the air inlet and the air outlet are positioned on the perimeter of the tire distant from each other by a preset length, dependent on the deformation of the tire.

An exemplary system for controlling air pressure in a tire of a vehicle includes an air transfer ring assembly including a reservoir member, a cover member, a first air transfer member, a second air transfer member, and a sealing member configured to seal the reservoir member against the cover member and defining a pressured reserve air chamber. The reservoir member is coupled to a hub assembly of the vehicle and the cover member is coupled to a brake assembly of the vehicle to facilitate the transfer of air to and from a rotating vehicle component and a stationary vehicle component.

The present invention provides a tire pressure regulation system for use in a pneumatic tire mounted on a vehicle to continuously maintain a predetermined optimum pressure by automatically inflating or deflating the tire as needed. The system employs one or more actuators, an air pump pneumatically coupled to the tire and a motion reversal device coupling the actuator and the piston of the pump. The actuators are controlled by the tire pressure in one direction and the tension of one or more springs in the other direction. The springs are attached to the handle of the piston at one end and the body of the pump at the other end to provide the appropriate tension to maintain the optimum pressure in the tire. When the tire pressure is low the pump piston is pulled out. The piston pumps air into the tire when the pulled out pump piston is pressed against the road while the vehicle is in motion. A separate rod coupling the piston handle and a valve in the tire is also provided to deflate the tire when the tire pressure is higher than a predetermined high pressure value.

A tire apparatus is provided, the apparatus including a tire body for attachment to a wheel rim to define a first inflatable volume. An inner chamber defines a second inflatable volume which is located within the first inflatable volume of the tire body. A first fluid communication path is provided between the first and second inflatable volumes and a second fluid communication path is provided between the first inflatable volume and the atmosphere. A first valve opens and closes the first fluid communication path, and a second valve opens and closes the second fluid communication path. The tensile strength and pressure-containing capacity of the material structure of the second inflatable volume is greater than that of the tire first inflatable volume. A first fluid pressure within the first inflatable volume of the tire body is optimisable by opening the first valve to allow pressure transfer from the second inflatable volume into the tire body, and/or opening the second valve to allow pressure to vent from the tire body to atmosphere. A vehicle wheel and active tire pressure control system incorporating the tire apparatus are also provided.