The invention concerns a device in wheeled walker or rollator, comprising a frame member (2) having a lower end (3), a handle support rod (4) having an upper end (5), a brake-control means (6) arranged at the upper end (5) of the handle support rod, said brake-control means (6) being movable between a neutral position and a brake-application position. The rollator comprises a wheel (7) located at the lower end (3) of the frame member, the distance between said wheel (7) and the brake-control means (6) being changeable, a brake element (8) located adjacent the wheel (7), an upper force-transmission member (9) connected to said brake-control means (6), a lower force-transmission member (10) connected to said brake element (8), and a coupling means (11) for coupling-together said upper and said lower force-transmission members (9, 10). The upper force-transmission member (9) and the lower force-transmission member (10) are arranged to move freely relative to one another, when the brake-control means (6) assumes its neutral position and. The upper force-transmission member (9) and the lower force-transmission member (10) are arranged to be interconnected by means of said coupling means (11), when the brake-control means (6) leaves the neutral position, in response to which braking force is transferred to the brake element (8).Linvention concerne un dispositif à roues destiné à un appareil de marche ou Rollator, qui comprend un élément de cadre (2) possédant une extrémité inférieure (3), une tige de support de poignée (4) comprenant une extrémité supérieure (5), un organe de commande des freins (6) ménagé à lextrémité supérieure (5) de la tige de support de poignée, ledit organe de commande des freins (6) pouvant se déplacer entre une position neutre et une position dapplication des freins. Lappareil de marche comprend une roue (7) disposée à lextrémité inférieure (3) de lélément de cadre, la distance entre ladite roue (7) et lorgane de commande des freins (6) étant modi
