History of Garage Doors: Part 2
The history of garage doors: Part 2 is a series of posts dedicated to educating the public on garage doors. A torsion spring counterbalance system consists of one or two tightly wound springs. These springs are on a steel shaft (torsion tube) with cable drums at both ends. The entire apparatus mounts on the header above the garage door and has three supports. A center bearing plate with a steel or nylon bearing and two end bearing plates at both ends. The springs themselves consist of the steel wire with a stationary cone at one end and a winding cone at the other end.
Attached to the center bearing plate is the stationary cone. The winding cone consists of holes every 90 degrees for winding the springs and two set screws to secure the springs to the shaft. Steel counterbalance cables run from the roller brackets at the bottom corners of the door to a notch in the cable drums. When the door is raised, the springs unwind and the stored tension lifts the door by turning the shaft. Thus turning the cable drums, wrapping the cables around the grooves on the cable drums. When the door is lowered, the cables unwrap from the drums and the springs are rewound to full tension.
Life of torsion spring
Also Garage door manufacturers typically produce garage doors fitted with torsion springs that provide a minimum of 10,000 to 15,000 cycles and are guaranteed for three to seven years. One cycle is a single opening and closing sequence. Most manufacturers offer a 30,000 cycle spring. However, it is important to remember that if the weight of the garage door is increased by adding glass, additional insulation, or even several coats of paint, the life of the torsion spring may be greatly reduced.
Other factors like poor garage door maintenance, loose tracks, or components shorten torsion spring life. Owners need to avoid applying grease to garage door tracks because that makes the wheels “skate” in the track instead of turning. Only bearings, hinges, and spring wire require lubricant.
Extension spring lift mechanism
An extension spring counterbalance system consists of a pair of stretched springs running parallel to the horizontal tracks. The springs lift the door through a system of pulleys and counterbalance. Cables running from the bottom corner brackets through the pulleys. When the door is raised, the springs contract, thus lifting the door as the tension is released. Their lifting weight capacity can best be identified by the color that is painted on the ends of the springs.
Furthermore, Maintenance of garage door is described in the manufacturer’s instructions and consists of periodic checks for correct operation, visual inspection of parts, and lubrication.