A sub frame (8) with wheels (12) is connected to the main frame (1), and is movable between collapsed and extended positions. Its connection to the frame is via a coupling (9,13-16) comprising an upper cross piece (9) and a vertical guide (13) on the main frame. The coupling has a link arm (14) below the guide (13) which, by means of articulations (15,16), is connected to the frame and subframe, permitting simultaneous pivoting and lifting of the subframe relatively to the frame part, and lifting the main frame hand grip (5).
展开▼
