Tilting vehicle and a method of tilting a vehicle with rear wheel supports having hydraulic cylinders communicating through a pump

A vehicle comprising:

• a chassis, at least one front wheel, two surface-engaging rear wheels and a propulsion unit for driving the rear wheels, each rear wheel being connected to the chassis by a wheel support assembly comprising:
• a rear wheel support for allowing movement of the respective rear wheel relative to the chassis;
• and
• a hydraulic cylinder, the hydraulic cylinder comprising:
• a housing connected to one of the chassis and the rear wheel support;
• and
• a piston connected to the other of the rear wheel support and the chassis, the piston being moveable within the housing and arranged to divide the hydraulic cylinder into first and second chambers each having respective ports configured to allow hydraulic fluid to enter and exit the respective chamber,
• the ports of the first chambers of each hydraulic cylinder being in fluid communication and the ports of the second chambers of each hydraulic cylinder being in fluid communication such that movement of hydraulic fluid from the first or second chamber of one hydraulic cylinder to the respective first or second chamber of the other hydraulic cylinder displaces the pistons of the hydraulic cylinders in opposing directions relative to the respective housings and causes the chassis to articulate with respect to the ground surface, wherein the vehicle further comprises a pump arrangement, a bypass valve arranged in parallel with the pump arrangement and a control arrangement comprising a control device to enable the user to steer the vehicle, the movement of hydraulic fluid being selectively controlled by the pump arrangement, wherein, in a first mode of operation, the at least on front wheel is steerable by operation of said control device and said control arrangement is configured to open said bypass valve to bypass said pump arrangement such that movement of hydraulic fluid from one hydraulic cylinder to another can be accomplished by application of a force to one side such that the chassis is caused to tilt downwards on the side to which the force is applied.

A vehicle comprising:

• a chassis, at least one front wheel, two surface-engaging rear wheels and a propulsion unit for driving the rear wheels, each rear wheel being connected to the chassis by a wheel support assembly comprising:
• a rear wheel support for allowing movement of the respective rear wheel relative to the chassis;
• and
• a hydraulic cylinder, the hydraulic cylinder comprising:
• a housing connected to one of the chassis and the rear wheel support;
• and
• a piston connected to the other of the rear wheel support and the chassis, the piston being moveable within the housing and arranged to divide the hydraulic cylinder into first and second chambers each having respective ports configured to allow hydraulic fluid to enter and exit the respective chamber,
• the ports of the first chambers of each hydraulic cylinder being in fluid communication and the ports of the second chambers of each hydraulic cylinder being in fluid communication such that the movement of the hydraulic fluid from the first or second chamber of one hydraulic cylinder to the respective first or second chamber of the other hydraulic cylinder displaces the pistons of the hydraulic cylinders in opposing directions relative to the respective housings and causes the chassis to articulate with respect to the ground surface, wherein the vehicle further comprises a pump arrangement, the movement of hydraulic fluid being selectively controlled by the pump arrangement;
• wherein the pump arrangement comprises a bidirectional pump.

A method of tilting a vehicle comprising a chassis, at least one front wheel, two surface-engaging rear wheels, a centreline extending from the front to the rear of the chassis, and a propulsion unit for driving the rear wheels, each rear wheel being connected to the chassis by a wheel support assembly, the wheel support assemblies and the chassis being arranged such that the chassis, the or each front wheel, and the rear wheels are configured to tilt in unison in either direction with respect to a vertical, upright position of the chassis such that the or each front wheel and each rear wheel lies in a plane parallel to the centreline of the chassis irrespective of the angle of tilt of the chassis, each wheel support assembly comprising:

• a rear wheel support for allowing movement of the respective rear wheel relative to the chassis, each rear wheel support and respective rear wheel being movable independently of the other rear wheel support and respective rear wheel in a plane parallel to the centreline of the chassis;
• and a hydraulic cylinder, the hydraulic cylinder comprising:
• a housing connected to one of the chassis and the rear wheel support;
• and a piston connected to the other of the rear wheel support and the chassis, the piston being moveable within the housing and arranged to divide the hydraulic cylinder into first and second chambers each having respective ports configured to allow hydraulic fluid to enter and exit the respective chamber, the ports of the first chambers of each hydraulic cylinder being in fluid communication and the ports of the second chambers of each hydraulic cylinder being in fluid communication;
• wherein the method comprises:
• selectively controlling a pump arrangement to move hydraulic fluid from the first or second chamber of one hydraulic cylinder to the respective first or second chamber of the other hydraulic cylinder in order to displace the pistons of the hydraulic cylinders in opposing directions relative to the respective housings and to cause the chassis, the or each front wheel, and the rear wheels to tilt with respect to the surface.