A wheelchair including a base assembly that has a first side and a second side. At least one caster and a drive wheel are mounted to each of the first and second sides. The wheelchair includes a seat assembly having a seat and a backrest and an actuator assembly having a plurality of actuators. Each actuator can expand and retract and includes a first end pivotably connected to the base assembly and a second end pivotably connected to the seat assembly. The actuator assembly allows for at least four degrees of movement of the seat assembly with respect to the base assembly. The wheelchair includes a computer that is connected to the actuators and that controls the movement of the actuators. The computer moves the actuators to vary the position of the seat assembly with respect to the base assembly.

In a four-wheel vehicle with vertically independently movable wheels (2, 2, 3, 3), diagonally opposite wheels (2, 2 or 3, 3) are connected to one another by respective cables (9, 90) guided over deflection rollers (11 to 15).

The traction cable mounting makes it possible to adapt the height of the wheels in the event of equal loading of the individual wheels independently of the terrain.

A wheel with a suspension system being connectable to a vehicle, like a wheel chair. The wheel includes a hub and a rim rotatable about the axle of the hub. Between the hub and the rim, a number of support members is located. The support members are adapted to retain the distance when stressed up to a threshold value and recoverly alter the distanced when stressed over this threshold value. Exemplary support members are spring elements, damping strokes by compression if the support member is compressed or elongated. The spring elements may be preloaded.

This invention provides a wheelchair with four wheel independent suspension and modular seating, allowing for customized seat selection and a variable ride. It includes a chair assembly, a chassis assembly and a suspension assembly. The chair assembly includes a seat; a seat mount; a seat angle adjuster; and a pillar. The chassis assembly includes a chassis; and a handle assembly. The suspension assembly includes a forward suspension assembly and a rear suspension assembly. In another embodiment, the wheelchair includes a chair assembly with handles, a main cross beam and a suspension spring assembly.

A wheelchair of the mid-wheel drive type has a chassis frame, a pair of from and rear link arms that are pivotally connected to the chassis frame. Front caster wheels and drive wheels are fixed to the front link arms. Rear caster wheels are fixed to the rear link arms. A coupling operatively connects each front link arm to an adjacent rear link arm to transmit pivotal movement of one of the front and rear link arm to an opposite pivotal movement of the other of the front and rear link arm.

A wheel with a suspension system being connectable to a vehicle, like a wheel chair, comprises a hub (38) and a rim (34) rotatable about the axle (42) of the hub (38). Between the hub (38) and the rim (34), a number of support members (40) is located. The support members (40) are adapted to retain the distance when stressed up to a threshold value and recoverly alter the distanced when stressed over this threshold value. According to the invention, the support members (40) are comprising spring elements (50), damping strokes by compression if the support member (40) is compressed or elongated. The spring elements (50) are preferably preloaded.

A mobility vehicle may comprise a frame, a first pivot arm, a second pivot arm, and a suspension assembly. The first pivot arm may be coupled to the frame and coupled to a drive wheel. The second pivot arm may be coupled to the frame and coupled to a ground engaging caster wheel. The suspension assembly may be coupled to the frame. The suspension assembly may include a first spring assembly and a second spring assembly. The first spring assembly may be disposed about a first spring axis and coupled to the first pivot arm. The second spring assembly may be disposed about a second spring axis and coupled to the second pivot arm. The first spring axis and the second spring axis may be disposed relative to each other at an angle of no greater than about 150 when the mobility vehicle is operating on horizontal ground.

Several embodiments of wheeled vehicles, such as wheelchairs, that are adapted to traverse obstacles are disclosed. The wheeled vehicles include a frame, drive wheels, front anti-tip wheels positioned in front of the drive wheels, and rear anti-tip wheels positioned behind the drive wheels. One exemplary vehicle includes front anti-tip wheels supported by rigid arms that are fixed to the frame and drive assemblies that are independently suspended from the frame. Another exemplary vehicle includes a linkage that links the front and rear anti-tip wheels, such that movement of one of the front anti-tip wheel or the rear anti-tip wheel relative to the frame causes movement of the other wheel relative to the frame.