The Garage door torsion spring a mysterious object that you never knew existed until it was broken. Followed by a bang in the night, day or maybe when ever a spring dissapear. Usually garage door springs break due to metal fatigue joined with oxidation. You see, the common cold-rolled steel variety is extremely vulnerable to rust as well as it is generally a brittle metal. A preferred garage door torsion spring is one with the coil manufactured with galvanized steel. The reason why these springs work are due to a rotational potential energy built up in them. Garage door springs are pre-loaded with a list of torsion bars and then locked into a torsion tube via set screws. The rotational energy is then translated down the tube and increased via a pulley until finally being distributed as a tension via a cable on either side of the door.
This cable should have tension always approximately equal to the weight on the vertical part of the door regardless of position it is in. Its for this reason that your garage door feels or should feel weightless through out all positions of its travel. As load is applied to a torsion spring, the springs diameter will decrease, reducing the outdoors and inside diameters. The spring will also grow in length. In most cases is it wise to the style of a torsion spring to wind in the direction of the coil winding. Should the design require that the torsion spring wind in the unwinding direction, maximum load should be and examples of wind should be lowered. Normally, torsion spring are designed of a shaft or mandrel. The shaft will ensure spring stability and location.
See also: Roll Up Garage Doors
Garage Door Torsion Spring Gallery