Guide rail and carriage, especially for a roller blind in a motor vehicle

The guide rail (10) consists of an extruded profile which accommodates a sliding carriage (12) with a braking portion (26) carrying a brake pad (28) on either side. The brake pads engage the tapered sides of a groove in the rail. Sliders (38) are pushed against another part of the rail by a spring (34) whose central part (36) is fastened to the sliding carriage. The sliding carriage may tilt and has rounded corners (42), to obviate jamming.