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Tag Archive: Constant Force Springs

  1. Custom Springs for Fire Dampers

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    Custom springs for fire dampers infographic.

    Custom Springs for Fire Dampers

    Fire dampers need durable, dependable spring components to function effectively. Our springs ensure fire dampers operate efficiently where smoke and fire can rapidly escalate dangers, playing a critical role in saving lives. We offer high-quality, precise spring solutions for duct, HVAC, and automatic fire dampers, meeting the demands of these essential installations.

    What Is a Fire Damper?

    Ductwork and vents are vital for maintaining health, comfort, and safety by ensuring adequate airflow and temperature control. Unfortunately, they also provide ready conduits for smoke and flame to spread quickly, accessing additional oxygen and fuel during a fire. Fire dampers prevent this spread, they act as valves that automatically or manually close. Typically using a spring-based mechanism, fire dampers halt advancement upon detecting the heat of a fire.

    Types of Fire Dampers

    Spring-loaded fire dampers offer protection in various ducts and conduits. Here are three common types:

    • Duct Fire Dampers: Installed in duct penetrations they can be manual or dynamic, using a spring mechanism to close and open.
    • HVAC Fire Dampers: Spring-actuated fire dampers in HVAC systems generally close upon detecting a lack of air pressure.
    • Automatic Fire Dampers: These dampers close automatically when environmental conditions reach a set temperature threshold.

    At John Evans’ Sons, we produce springs for all these fire damper types.

    The Role of Springs in Fire Dampers

    Springs ensure fire dampers work properly by providing the power needed to operate the blades or panels inside the dampers. Specifically, these springs:

    • Facilitate simple operation by closing to block flames and smoke when the fusible link breaks, triggering their closure.
    • Allow automatic or manual reopening for regular airflow when safe.

    Installing or replacing springs with top-quality, appropriately sized, and styled springs ensures fire damper performance meets and exceeds safety requirements.

    Springs Most Commonly Used in Fire Dampers

    While traditional helical or round wire springs are used in fire dampers, constant force springs, and spiral torsion springs are most common.

    Two Constant Force Springs next to each other.Constant Force Springs

    Constant force springs, supply steady and consistent force and are well-suited for the curtain opening and closing actions needed in fire dampers. Commonly used in medical devices, retail displays, and windows, they offer extended, dependable performance. Typically made of stainless steel, their benefits include:

    • Stable, consistent force
    • High power under tight space constraints
    • Smooth, reliable extension and retraction
    • Versatile mounting capabilities with customizable end designs
    • Multiple installation configurations for varying load requirements

    The spring’s coil diameter and material thickness determine its life cycle.

    Spiral Torsion Spring.Spiral Torsion Springs

    Spiral torsion springs provide smooth winding and unwinding, ideal for applications like truck tarps systems, electric motors, medical equipment, and fire dampers. Made from a coiled strip of metal and often of steel for fire dampers, their benefits include:

    • Exerting high rotational torque from small rotations
    • Smooth, powerful action
    • Extremely durable and long-lasting
    • Easy to use and adjust
    • Fit in various settings, especially those with limited space

    Picture of John Evans' Sons', Incorporated, facility with logo top left.John Evans’ Sons Fire Damper Spring Design

    John Evans’ Sons has specialized in spring innovation and manufacturing since the era of horse-drawn buggies. We produce reliable, powerful springs and spring-based assemblies for industries including medical, aerospace, robotics, and window manufacturing. Our extensive in-house capabilities allow us to produce various spring types and customized solutions to meet diverse needs.

    Contact us to learn more about our capabilities or to request a quote for your fire damper and other spring-related applications.

  2. Exploring Constant Force Spring Benefits for Your Application

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    Crucial Components

    Selecting the right mechanical components for your application is crucial. Among the various options available, constant force springs stand out for their unique properties, versatility, and benefits. They are a type of extension spring that does not obey Hooke’s law, maintaining a constant force even when deflected. Let’s delve into the advantages of a constant force spring mechanism and why they might be the perfect choice for your application.

    About Constant Force Springs

    Two Constant Force Springs next to each other

    There are many constant force spring benefits due to their superior spring properties. In the form of a tightly wound roll of strip spring material, they are more compact and lighter than most other methods as a balancing mechanism. This eliminates the need for deadweights, linkages, cylinders, and other systems.

    Offering long deflection, without significant friction, as a return or retracting mechanism, providing a smooth, even, uniform load through the entire length of travel. Providing steady pressure to electric motor brushes for the full life of the brushes, feeding staples into a surgeon’s suturing tools, and is useful in countless other situations where constant force must be applied to a moving or moveable object.

     

    Constant Force Spring Benefits

    1. Small Space Requirements

    Their design allows tight coiling, making them an excellent choice for devices with limited space.

    1. Smooth Range of Motion

    The nearly flat force curve ensures a consistent force throughout their extension. This provides a smooth and reliable range of motion, essential for applications requiring precision and stability.

    1. No Inertia to Overcome

     Unlike traditional springs, they do not have significant inertia to overcome at the beginning of their movement. This makes them ideal for applications that require immediate and responsive action.

    1. Easy Mounting to Existing Hardware

    Versatile and easily integrated into existing hardware setups. This flexibility simplifies the design process and can reduce manufacturing time and costs.

    1. Counterbalance Effect

    Useful in applications where a constant load needs to be counterbalanced, such as in retractable mechanisms or adjustable systems.

    Versatile Applications

    Constant force spring benefits make them suitable for a wide range of applications, including:

    • Surgical Devices: Enhancing precision and control in medical instruments.
    • Aircraft Doors: Used in a “gang” arrangement, i.e. side by side in a multi-spring assembly. This allows for hundreds of pounds of counterbalance force to be available to assist in opening & closing the main entry door/stairs, or cargo doors.
    • Windows: Providing a counterbalance for smooth opening and closing operations.
    • Fire Dampers: Supply steady and consistent force, and well-suited for the certain opening and closing actions needed in fire dampers.
    • Gym Equipment: Replace the need for weights in gym equipment using the force of the springs to act the weight. 50 pounds of force in a lightweight spring is then 50 pounds of weight saved, making the equipment lightweight and more compact.
    • Electric Motors: The springs allow the motor to run efficiently without arcing or other gaps in power. As the commutator turns, the brushes become worn over time due to friction. The springs ensure proper contact force against the commutator as they wear.

    Consider Constant Force Springs for Your Next Project

    Considering these springs for your application? It’s important to work closely with a trusted manufacturer to ensure the best design and implementation. John Evans’ Sons, a leader in constant force spring manufacturing, offers extensive selection charts and technical information to help you choose the right spring for your needs.

    We produce reliable, powerful springs and spring-based assemblies for industries including medical, aerospace, robotics, trucking, and window manufacturing. Our extensive in-house capabilities allow us to make various spring types and customized solutions to meet diverse needs.

    Contact John Evans’ Sons

    Already know what you need? Reach out to John Evans’ Sons for expert assistance in selecting and implementing the perfect constant force spring for your application. Their expertise and high-quality products can help ensure the success of your project.