Self-locking fastening for up-and-over doors, with tension spring

摘要

The up-and-over door is held by interfitting tension spring tubes (a-d) with graded lengths. The tubes have two-part screw-in plugs (e-h) and threaded nuts (i) and screwed door connection (k,m) together forming a common tension spring end. The threaded nuts and the screwed door connection are formed with a left-hand thread on a shared tension spring end. The two screw-in plug is in the form of a standardised polyamide injection moulded parts.