A raising wheelchair comprising: a wheeled frame; and a raising system mounted to the frame and supporting a seat and a backrest (19, 22), the raising system being configured to be movable between a lowered position and a raised position, the raising system comprising; at least one double-armed lever including a first lever member having a first end and a second end and a second lever member having a first end and a second end; a coupling member fixedly mounted to the frame, wherein the first end of the first lever member and the first end of the second lever member are pivotally coupled to the coupling member; and a coupling mechanism comprising: a first component fixedly coupled to the backrest (19, 22), a second component comprising a disk-shaped member slidably engaged with the second end of the first lever member so that the second end of first lever member slides along an outer perimeter of the second component, and a third component pivotally coupled to the second end of the second lever member; wherein the raising system is adapted to maintain an orientation of the backrest (19,22) relative to the ground that is consistent throughout substantially an entire range of movement between the lowered position and the raised position. a wheeled frame; and a raising system mounted to the frame and supporting a seat and a backrest (19, 22), the raising system being configured to be movable between a lowered position and a raised position, the raising system comprising; at least one double-armed lever including a first lever member having a first end and a second end and a second lever member having a first end and a second end; a coupling member fixedly mounted to the frame, wherein the first end of the first lever member and the first end of the second lever member are pivotally coupled to the coupling member; and a coupling mechanism comprising: a first component fixedly coupled to the backrest (19, 22), a second component comprising a disk-shaped member slidably engaged with the second end of the first lever member so that the second end of first lever member slides along an outer perimeter of the second component, and a third component pivotally coupled to the second end of the second lever member; at least one double-armed lever including a first lever member having a first end and a second end and a second lever member having a first end and a second end; a coupling member fixedly mounted to the frame, wherein the first end of the first lever member and the first end of the second lever member are pivotally coupled to the coupling member; and a coupling mechanism comprising: a first component fixedly coupled to the backrest (19, 22), a second component comprising a disk-shaped member slidably engaged with the second end of the first lever member so that the second end of first lever member slides along an outer perimeter of the second component, and a third component pivotally coupled to the second end of the second lever member; a first component fixedly coupled to the backrest (19, 22), a second component comprising a disk-shaped member slidably engaged with the second end of the first lever member so that the second end of first lever member slides along an outer perimeter of the second component, and a third component pivotally coupled to the second end of the second lever member; wherein the raising system is adapted to maintain an orientation of the backrest (19,22) relative to the ground that is consistent throughout substantially an entire range of movement between the lowered position and the raised position.