Blog Archive: February 21, 2011
Here’s the inside look of a sectional door:
1. Torsion Spring
Counterbalances door’s weight so that it can be lifted easily.
Guides door up to ceiling and back.
Rides inside track. Steel ones are noisy; nylon is quieter.
Connects horizontal sections.
6. Lock Bar
Engages with track to prevent door from opening.
Seals door edges against air infiltration.