Garage Door Springs: An Understated Part
Garage door springs are an essential part of any well-built garage door system, as their purpose is to provide the counterbalance to the weight of the door in order to make it much easier to open and close. They have the same use that their older counterparts have had for the past several centuries, balancing doors from the past to the present-day, modern doors that we use currently. As an example to how a garage door spring works, if the average garage door weighs about 100 pounds, then a spring force of an equal 100 pounds is needed in order to successfully provide pull against the door’s weight. The way the spring accomplishes this is to either stretch and contract itself, or apply torsion to special parts that assist in balancing the door.
Replacing these garage door springs can potentially be dangerous for those that do not know their way around them, as the amount of torque force in a wound up torsion spring or the stretch force in an extended spring can be several hundred pounds which is enough to cause injury to someone. Repairing garage doors often include completely replacing certain garage door parts that are tied into the spring system itself, and unfortunately, due to the nature of the spring force possible many people have injured themselves and have even lost their lives because of injuries suffered due to not exercising the proper caution or knowing what to do in the proper manner. Working knowledge of garage components like garage door springs, garage door weights, and other garage door parts, as well as how these work and combine together are needed in order to correctly, and more importantly, safely operate and repair these parts.
Garage Door Torsion Springs and Their Properties
The garage door torsion springs are of a garage door system are securely fastened to a metal shaft directly above the garage door itself. Depending on the design and type of system, the metal shaft can pass through in any number of ways, with a few being: through the middle of the spring or spring system, close to the springs, or even housing the spring system itself in certain cases. If the metal shaft does actually pass through the middle of the torsion spring, then the spring can be mounted in the middle of said shaft, but it can also be mounted on the end of the metal shaft close to the outer edge of the garage door.
The way these torsion springs balance a garage door is to apply torque to this metal shaft with special drums that are attached to each end. Each of these drums has a cable fastened onto it that is also attached to a special type of fixture located at the bottom of the garage door, extending all the way down to it when the door is closed. The torsion spring, along with the cables, extend and contract as needed when the garage system is either opened or closed, helping the balance to do either one. There are three main qualities of a torsion spring that determine the lift it produces as well as its cycle life. These three characteristics include: the size, or gauge, of the wire, the inside diameter of the spring, and the overall length when contracted or extended or at rest. All three of these qualities determine the lift, which is the total amount that the torque of the spring can provide, which in turn determines the maximum amount of weight that the spring can safely hold. The other characteristic is the cycle life, which is simply the amount of times that one can open and close their garage door before the spring degrades and ultimately breaks.
Standard Residential Torsion Springs
Torsion springs of the standard variety are the most common type of residential torsion springs in the whole garage door industry. Residential grade garage doors almost always use one of two types of torsion springs. On the lighter end of the garage door spectrum, one spring can satisfy the requirements for the load of the garage. In that kind of situation, the torsion spring can be attached to a spring anchor bracket in the exact center of the metal shaft that is in the middle of the garage door. In other cases, the spring has an off-center, or offset, type of mount, which means that the torsion spring will simply not be installed in the spring anchor bracket in the center of the door, as it will be somewhere else.
If the garage door is heavy or much heavier than normal, then two torsion springs will usually be required. If there are two torsion springs balancing a garage door, they are usually attached to the spring anchor bracket that is located above the center of the garage door. Using two springs on a garage door typically means that the system is safer, for various reasons, one of which is that if one spring does break or snap, then there is another slowing it down or holding it in place when the door is opened. The other spring will hold the door in place for an amount of time, usually enough for the person to avoid any further incidents, preventing damage to the garage door and injury to the person.
Standard Commercial Grade and Industrial Grade Torsion Springs
Commercial and Industrial Garage doors, for the most part, contain at least two or more torsion springs. A large percentage of these doors make use of four springs at a time, in a number of designs and setups which include, but are not limited to: linear type, duplex type, triplex type, or mixed type.
The linear type system of garage door springs comes into use when a larger, wider kind of vehicle needs to fit inside, like a semi-trailer or a tractor, etc. Since these garage doors need to be much wider than normal, four or more torsion springs are lined up on the metal shaft easily. Clients that choose to install a linear type system acquire the advantage of having less material requirements than other types of systems, thus reducing the total cost of the garage door project.
The duplex type of system are more intricate, and at first appear to have only two springs attached to each side of the garage door. However, if one looks closer at each spring, you’ll discover that the springs are outer springs, and the bigger springs house one smaller spring inside of them with a smaller diameter. The duplex type of spring system is able to supply more torque, and with it, more total lift in a smaller space without needing more space for the other springs due to its design.
The triplex type of system looks and functions almost exactly like the duplex system, with the main difference being that instead of one spring inside a larger, outer spring, the outer spring actually houses two smaller spring on each side of the door, for a total of six torsion springs attached to the garage door.
The mixed type of spring system, as you may have already guessed from its name, actually combines the best of all the other systems, linear, duplex and triplex into one combined spring system. Mixed systems tend to have more than one, or multiple, set of both duplex and triplex springs on each side of the garage door. This option is possible for those clients whose garage door metal shaft is large and wide enough to be able to fit multiple springs inside of it. If the garage door in question is extremely heavy compared to other doors, then it is a safer and better option to just attach multiple sets of duplex spring pairs to the garage door itself. However, while these types of spring systems are very safe, it can often be difficult to examine the inner springs and decide whether they are worn out and in need of repair or replacement.
Since commercial grade garage doors usually weigh more, the torsion springs used by these doors need to have a larger inside diameter as well as a bigger wire size in order to safely operate within the door, when compared to a residential grade garage door system. Many spring systems on various garage door metal shafts have a 1 inch outside diameter, but some metal shafts happen to need a 1 ¼ inch outside diameter. These metal shafts are full of bearings, drum cables, and a type of winding cone that has the 1 ¼ inch opening for the metal shaft. Garage doors that are bigger and heavier are more often than not equipped with solid metal shafts, while the lighter, smaller garage doors make use of hollow metal shafts. Certain solid metal shafts come with a groove cut out on the surface of it, resulting in a keyed shaft that, when combined with its own respective shaft key, helps to keep the cable drums in place and not spinning around loosely.
Singular-Piece Curtain Door Torsion Springs
One-piece curtain garage doors and steel rolling doors have a similar method of operation when compared to one another, and these types of doors are most commonly found in self-storage facilities. Those in the business of garage doors like to call them “mini-warehouse” doors or “self-storage” doors due to the fact that that’s exactly what they are and where they can be found, and they all come in a wide variety of shapes, builds and sizes.
The manufacturers of these doors roll them from a single piece of steel sheet metal, which is why they only have one piece. While steel rolling doors actually use a series of interconnecting slats or parts to make up the curtain, “self-storage” doors are just one big piece of rolled sheet metal. When someone opens the door, the curtain moves along the edge of the cable drums, which in turn are attached to the shaft, as previously mentioned. Due to the nature of the way these doors work, they are also known as “steel rolling doors” as well as the more heard-of term, “roll-up doors”.
Along the axle of the system, in evenly spaced intervals, are the circular cable drums, which help to provide support for the curtain as the door opens or closes. The torsion springs inside are attached to the outer cable drum with a large bolt. On average, a set of two torsion springs provides balance to a door, with one on either side of it.
The other end that’s not attached to the cable drum is instead mounted to the door bracket which is located just outside the door. The axle itself passes through the middle of the bracket, the middle of the torsion springs, and then through the cable drums. Several garage door manufacturers such as Janus International and Trac-Rite design garage doors with a specialized adjustment wheel to change the tension of the system, while manufacturers like DCBI do not include this adjustment tool. Those doors that do include an adjustment tool for tension also include a type of steel housing closing around the drums that hide the torsion springs from view, while the garage doors that do not make use of an adjustment wheel usually have their springs completely visible when the door is open.
Garage Door Extension Springs
Garage door extension springs will usually be secured to the sides of a garage door, sometimes above the horizontal tracks. These types of springs contract and extend when the door is opened or closed and are the counterweight to the weight of the door. Typically, residential garage door systems only contain two extension springs, with one each side of the door. Garage doors used in commercial and industrial sectors, and even certain residential-use doors make use of several springs on each side of the door. Extension type springs are designed to have loops in them, whether it’s an open loop, a closed loop, or a loop with clipped ends that secure the spring to the track hang, pivot pin, frame, pulley or tension bolt.
Sectional Garage Door Extension Springs
Sectional Garage Door Extension Springs are the type of spring more exclusive to the United States. These types of springs extend above the horizontal tracks on each side, as well as parallel to them. They pull on the cables to support and counterbalance the door. When the door closes, all of the weight goes from the horizontal tracks to the cables, which are also supported by the extension strings which stretch out and pull against the door, making it very easy to open and close.
Residential garage doors, with usually only one spring on each side of the door, have their springs connect to bolt that has an open eye at one end. This bolt is then attached to the garage door frame by way of a beam or a track.
At the other end of an extension spring, a pulley is connected to it by way of a pulley fork. The end of the cable that goes over the pulley is connected with a clip for cable adjustment. Attached to the clip itself is an S-hook, which is then connected to the horizontal track. The end of the cable continues over a second pulley, which ends up at the bottom part of the garage door in a special fixture attachment point.
Although residential doors have a relatively simple setup, the truth is that commercial and industrial garage doors have similar system of operation. With garage doors that are much heavier, special connection kits are used to connect the various ends of the extension springs, which allows the use of multiple springs on each side of the garage door.
Although this design is common, not all commercial and industrial garage doors make use of this type of setup. Certain ones will just have one extension spring on either side. On average, though, the rest of the setup itself looks and works about the same as a residential setup. While both commercial and residential garage doors use pulleys to lift the doors, commercial pulley systems tend to be much stronger and have a greater load capacity in order to be able to lift bigger, heavier doors without breaking.
One-Piece Garage Door Extension Springs
Like the name says, one-piece garage door systems operate as one large, self-contained piece. As the door is opened, the top of the door moves inside on the tracks, while the bottom part of the door moves to an outside direction. The extension springs then pull on a pivot pin, or an attachment point, to counteract the door’s weight. With that in mind, seeing how the bottom of the door moves both inside the garage as well as outside of it, coating this type of door with a weather deterring agent is not that effective. To this effect, one-piece garage doors are used almost exclusively in regions with more temperate weather.
As we’ve said before, one-piece garage door systems use a series of springs, pulleys, and cables as a counterweight to the door itself, averaging about 2 to 4 extension springs as its main means of counterbalance. The bottom of the spring is attached to an adjustable bolt, which is connected to a mounting bracket on the bottom of the door, while the top of the spring is has an open or closed loop clipped on to a pivot pin or another bolt. When in use, the extension springs stretch upward, coming in at a right angle to the garage floor, and are at length attached to a lever. This lever arm is then connected to the garage door itself. When you open the door, the extension spring contracts, which causes it to lose some of the stretch-out force it had.