Height-adjustable wheelchair

A wheelchair comprising a wheel frame and a seat frame connected to the wheel frame, the wheel frame being connectible to a set of front wheels and a set of rear wheels, the seat frame being configured with a seat plate for allowing a user to sit on it,

• wherein the position of the wheel frame relative to the seat frame is adjustable in order to make a height of a seat of the wheelchair adjustable,
• wherein the wheel frame and the seat frame are connected via at least one sliding bracket, the sliding bracket comprising a first mounting part connected to the wheel frame and a second mounting part connected to the seat frame,
• wherein the first mounting part and the second mounting part are coupled together in operational use,
• wherein in each sliding bracket one of the first and second mounting parts is provided with at least one elongated slot on a side facing the other one of the first and second mounting parts,
• wherein each elongated slot provides access to a respective internal channel for receiving a sliding bar which can move back and forth the respective internal channel,
• wherein the sliding bar is provided with at least one threaded hole for receiving a respective mounting bolt,
• wherein in each sliding bracket the other one of the first and second mounting parts is provided with at least one through-hole for receiving a respective mounting bolt,
• wherein the at least one through-hole is spaced apart and is aligned with the threaded holes in the sliding bar,
• wherein each mounting bolt is provided through the through-hole into the respective threaded-hole such that a sliding movement of one part relative to the other part causes the respective sliding bar to slide within the respective internal channel,
• wherein the sliding bracket having a first mode being a low-friction mode allowing adjustment of the height of the seat by sliding, by means of human force, the first mounting part relative to second mounting part in a stepless manner in a longitudinal direction of the bracket to obtain a desired length of the sliding bracket, the sliding bracket having a second mode being a high-friction mode resisting length adjustment between the first mounting part and the second mounting part and being capable of withstanding forces during mandatory safety, durability, and reliability tests for wheelchairs,
• wherein the first mode is obtained when the mounting bolts are partially loosened, and
• wherein the second mode is obtained when the mounting bolts are tightened.