Garage Door: Know About Its Mechanism


Contrary to popular views that garage doors have been in use only in modern times, the usage of garage doors actually dates back to 450 BC. Back then, chariots used to be stored in gatehouses. It was in the USA that the trend of using garage doors starter during the 20th century. So let’s explore more about garage doors:

Sectional garage doors

It is constructed using three to eight panels, these sectional doors slide up overhead. They also occupy the same internal garage space as a monolithic door does. But these doors have a better advantage over monolithic doors:

These doors don’t require space outside of the garage to open. So a vehicle can park quite close to the garage before opening up the door.

Each such panel of a sectional door comes with its own connections to the door track. This actually increases robustness and reliability in comparison to monolithic doors which only have a few connections in place for the whole panel.

Roller doors

Roller doors are constructed out of corrugated steel and they have evolved from being used as cover windows to door coverings. This corrugation gives the door strength to bear impacts, although other materials like corrugated fibreglass can also be used. A general car garage roller has a rolling mechanism which comes with a preloaded spring inside. The spring helps in reducing the effort required to open the garage door. For commercial premises, large roller doors are made which use a pulley and chain system that is operated manually to roll up or lower the door.

Thermal insulation of roller doors

It should be kept in mind that roller doors can’t be adequately insulated. But for thermal insulation, the door has a general insulation value of 4.9 till 5.2. In comparison, a sheet steel door has an insulation value of about 6.1 to 6.4.

Let’s talk about mechanisms used in garage doors:

Torsion spring lift mechanism

This counterbalance spring system is made up of one of two wound up springs on a steel shaft which has cable drums on its both ends. This entire mechanism is mounted on the wall above the door and has three supports:

A central bearing plate with nylon or steel bearing with two end bearing plates at the two ends are used. The springs used also consists of steel wire with a winding cone at one end and a stationary one at the other. This stationary cone is the one attached to the central bearing plate. On the other hand, the winding cone is made up of holes at every 90 degrees for winding up the springs, along with using two sets of screws to secure those springs to the shaft. Now, the steel counterbalance system runs from the roller brackets to the ones at the bottom corners of the door where there is a notch in the cable drums.

So when the door is raised, these springs unravel and the tension lifts the door by turning the cable drums. When the door gets lowered these cables unravel from the drums as the springs rewind to full tension.

Overall, garage doors use these mechanisms by keeping in various things like the material used, where the door will be used and more.