The Henderson canopy doors featured a long spring running across the top of the door, with the door supported by two side cables running up to a plastic cone attached to either end of the spring. Henderson made just two types: the Pre-Premier (manufactured pre-1992) and Premier (manufactured from 1992 onwards).
Henderson Premier doors followed on from the earlier Pre-Premier doors, and began manufacturing in 1993, up until 2010. Like the earlier model, these doors also had a single torsion spring running across the frame above the door, however the cables on the Premier doors were crimped with a ferrule, which clipped into a bracket attached to the roller spindle. The doors post-2004 introduced a safety ‘anti-drop’ device, which prevented the door from slamming shut in the case of the cables snapping.
The Henderson Ultra retractable doors featured fairly unique springs. Whilst the bottom of the spring featured a fairly standard looped end, the top end consisted of a bracket in the end of the spring into which an adjuster bolt was inserted (either with a hooked end or a nut-shaped end). These doors were made of timber in most cases, and were usually fairly heavy.
Henderson’s range of Dolphin doors retracted fully back into the garage when open, and comprised both single and double width doors. The springs were colour-coded for easy identification: yellow, grey and green.