Just look
- Hinges are available in a variety of torques and torque characteristics that can meet the needs of most applications.
- There are four basic types of hinges: constant torque hinges, bistable and retaining hinges, damping hinges and balancing hinges.
- The right hinges can almost make opening a 200-pound record feel like the records only weigh 10 pounds.
- Understanding the different torques that hinges can exert and which hinges are best for an application can help device and system designers produce quality products.
understand the couple
For hinges, torque is the amount of energy or force required to open or close a door or panel. The energy required depends on the weight of the door; the distance traveled or arc of movement from closed to open; and whether the hinge(s) are intended to hold the door or panel partially open or whether the door will always go from fully open to fully closed.
Today, hinge and positioning hardware manufacturers offer hinges and devices that cover a range of torques and have different torque characteristics. Engineers and designers select hinges with torque and options to meet the functional and ergonomic needs of their applications. These include:
- Hold doors open or closed and securely move panels into position without additional supports or additional components.
- Create zero-displacement motion to allow the door or lid to securely hold a user-defined or predefined position with a single motion when opened.
- Provide the right haptic feedback to give users a good idea of the quality of the case.
- Elimination of additional components (e.g. gas struts) or routine maintenance (re-tightening of bolts to maintain hinge strength), reducing overall costs.
- Provides a smoother, more powerful feel when opening and closing the door or to eliminate vibration.
The torque of a hinge affects the user's perception of a device. Look at the tray table on the plane. Designers must use extremely lightweight plastic components to help airlines reduce aircraft weight and save fuel.
However, if the tray falls a little and wobbles when you open it, passengers may question the quality of the plane itself. On the other hand, a properly chosen hinge with constant torque and a factory set resistance value will lower the tray with a force that will make the tray appear more solid, giving a good impression of the aircraft and airline. Also, well-made constant-torque hinges maintain the same strength after thousands of throws, without maintenance or replacement of parts.
the right hinge
The most common hinge is also the simplest: the hinge opens and closes with a free swing. Offers no resistance and users must use all required force to open or close the panel or rely on gravity
Beyond this basic device, hinges can be divided into four main categories based on the torque and controlled movement they provide:
- Constant torque hinges hold doors or panels in any position throughout the full range of motion.
- Bistable and locking hinges go automatically and hold certain positions like 90 degrees.
- Shock-absorbing hinges control movement speed.
- Counterbalanced hinges make heavier doors and panels feel lighter when opened or opened with a simple movement.
While many applications require only one type of hinge, features from different categories can be combined into hinges with multifunctional placement options.
Here are more details on each of the four types of hinges.
Constant torque hingesUse the friction between the blade and the pin to keep the hinge in the same position. Users, even casual users, quickly learn that no matter where the hinge is on its opening/closing arc, it takes the same amount of force to change the hinge's position. And it keeps the new position until someone moves it. A good example is a laptop lid. It opens and closes smoothly when someone opens or closes it. And if left partially or fully open, it stays that way and won't accidentally close.
Some friction hinges are adjustable, allowing users to increase or decrease the amount of friction on the pin and the torque required to move the hinge. However, constant torque hinges always move when a predetermined force is applied. It cannot be changed.
Mounted on constant-torque hinges (like Southco's E6 series), the boxed display tilts or rotates easily and stays in place despite the occasional touch, like signing your name or choosing a theater seat, without to move. The screen can be moved with one hand; no need to hold down a button or turn a lever.
Another type of constant torque hinge, unidirectional versions, deliver constant torque in one direction while providing free swinging motion in the other. This can be useful in applications such as storage cabinets with large doors. By removing friction from the hinge in one direction, the door opens but the torque prevents it from closing.
hingesHave the panels or doors swing open but at certain preset points e.g. B. half open and fully open, they can engage with a noticeable "click". Users can simply slide the door past a latch or detection point and out as well. These hinges are commonly used on lightweight cabinet doors that do not need to get in the way of the user opening them.
Bisagra beehiveA variation on retaining hinges, they contain a spring-loaded mechanism that drives the door or fixture to a preset angle when the door is opened. This is useful for doors, access panels or covers that need to open at a minimal angle for easy access.
damping hingesMake a door or compartment move constantly when opening or closing, instead of opening it or pushing the user to close it completely. This smooth, constant movement is increasingly preferred in many high-end applications such as automotive interiors, where the driver expects an intuitive user experience. For example, in glasses compartments and USB port holders, cushioned hinges reinforce the impression of a finely crafted, high-tech interior, a crucial element that many designers are looking for.
balanced hingesAllow heavy doors and panels to be easily opened and placed in the desired position. They use spring mechanisms that store energy when the door or panel is closed. When the door is opened, energy is channeled to support the door and reduce the user force required to fully open the door. In other words, they reduce the amount of effort required to open a heavy door.
In applications where operators routinely open and close heavy doors, such as For example, in industrial copiers, balanced hinges reduce operator fatigue and improve efficiency. For example, a door with a torsional symmetric hinge may require 60 pounds of force to fully open. A counterbalanced hinge, such as one of Southco's CB Series counterbalanced hinges, can reduce this to 3 lbs.
In the past, many engineers chose gas struts to provide the counterbalancing force instead of hinges. But these supports are prone to early failure. Counterbalanced hinges offer a cheaper and simpler alternative. Some of the newer counterbalanced hinges have a latch to aid in unfolding. When first opened, the hinge raises the door a few degrees, allowing the user to grip the panel more firmly to move it to the desired position.
Some of the most successful counterbalanced hinges use torsion bars, cams, and rollers to create and distribute counterbalanced force. They make opening an 80 pound plate feel like opening a 5 pound plate and the effort required to move the plate remains the same during the opening or closing movement.
key factors
There are three main factors to consider when choosing a hinge with the right torsion profile: weight, center of gravity and direction of movement.
Weight.If a panel is light enough (e.g. less than a few pounds), a simple, anti-twist hinge offers the most cost-effective alternative. As the weight of the door or panel increases, pivot hinges or constant torque hinges become more effective. The torque of these hinges requires some effort from the user, but also prevents the door from falling.
When the door panel weight is between 15 and 500 pounds, the counterweight becomes a more effective option. Balanced hinges prevent doors from sagging and make them lighter. This means users don't have to struggle to overcome the weight of the door to open or close it.
Main emphasis.The center of gravity of a door or panel is affected by the width and shape of the panel, as well as where other components attach to the panel. A light door with a center of gravity farther from the hinge point can feel the same as a heavier door with a center of gravity closer to the hinge point. For example, a tractor hood covering the engine compartment may be narrow and made of lightweight material, but because it's so long, the center of gravity is farther away. So more torque is required to lift than a box or slab that is only 12 or 18 inches deep.
Some newer counterbalanced hinges use torsion bars to provide the counterbalanced force. A cam and roller mechanism distributes this force throughout the range of motion. With this type of hinge, opening the hood of a 200-pound engine is like lifting a door that only weighs 10 pounds, and the force is balanced throughout the range of opening and closing motion.
direction of movement.For the direction of movement it is important to determine whether the panel or door is hinged vertically or horizontally. When it's vertically hinged and moving from side to side, it doesn't work against gravity like a horizontally hinged panel moves up or down. In some situations, a horizontally hinged door may need to be moved and maintained in a vertical position, for example to allow a technician to access assemblies within a machine. The force required to move the door from horizontal to vertical is greater, so a constant torque or balanced hinge may make more sense, especially when the technician is working under a door that needs to be held open.
the right feeling
Reputable hinge manufacturers know that every time a person opens, closes, or moves a hinge structure, they are essentially exerting a force. But they also experience a distinct tactile experience. For example, the erratic movement and screeching vibrations of a rusty, old, and misaligned hinge do not give the user a positive opinion of the device's quality or reliability.
The advent of more hinge technology, embracing a variety of torque options and contact point experiences, gives industrial designers a new set of tools to improve the user experience and therefore the perception they have of the devices they use.
This continuous pair offers the opportunity to create more sophisticated solutions. Depending on the requirement, different hinge types can be combined with different torsion profiles; For example, locking and damping functions can be combined in a single hinge, allowing a door to easily open and latch into a fixed position and then move on. automatically in the closed position in a controlled manner when closed.
The key is to determine the full use case for each application: what ergonomic effort is needed to open, position and close a device; and what user feedback is needed or desired to perform that movement effectively and repeatably. The ability to fully customize the torque level allows the designer to define what the end-user experience will be like. The industry's leading hinge suppliers have extensive experience working on these use cases to help define the optimal solution and can provide in-depth knowledge to cost-effectively configure the right hinge with the right torque for each application.
James Stroud is Product Business Manager atSouthco Inc.