GB1487329A - Spring loaded roller assembly for blinds - Google Patents

Abstract

1487329 Roller blinds L E J RAWSON and G W BRADBURY 15 Nov 1974 [13 Dec 1973] 57703/73 Heading A4B A roller blind assembly comprises a roller 11 mounted on a shaft or shafts 12 projecting from the roller ends, a spring mechanically interconnecting the roller and the shaft(s), support brackets at the roller ends, and co-operating cam and detent means mounted on the or a shaft and one of the brackets 14 to permit rotation of the shaft relative to the bracket 14 in one direction to pre-tension the spring and to prevent relative rotation in the opposite direction. As shown the cam comprises a toothed disc 16 secured to the shaft 12 and the detent comprises a tooth 19 or other projection carried by an elliptical shoulder 18 on the bracket 14. The shaft 12 has a hexagonal part 20 disposed between the cam disc 16 and the roller 11. To pre-tension the spring a spanner is engaged with the hexagonal part 20 and rotated in the direction A causing a lateral displacement of the cam disc 16 as its teeth 17 ride over the fixed tooth 19. When the spanner is removed after obtaining the desired pre-tensioning the spring reaction urges the cam disc 16 to the position of Fig. 2 to prevent reverse rotation. The assembly may include a check-action mechanism. Additional leaf or coil springs may bias the cam disc 16 into engagement with the detent tooth 19. In an alternative arrangement the cam disc could be carried by the bracket and the detent tooth by the shaft. The brackets may form end-walls of a box for the blind.