Posted by jla on | Comments Off on How Constant Force Springs Power Innovation in Medical Devices
Medical devices must deliver exceptional reliability, consistent performance, and user confidence. These standards become even more critical as devices continue to shrink in size, incorporate advanced automation, and rely on components that must perform smoothly and repeatedly under strict regulatory oversight.
ISO 13485 outlines the requirements organizations must meet to ensure their devices meet customer and regulatory demands for safety, consistency, and performance. John Evans’ constant force springs meet these demands by delivering smooth, uniform force output throughout their range of motion. Below, learn how constant force springs benefit medical applications and how John Evans’ Sons supports medical OEMs with certified, high-performance solutions.
Functional Advantages of Constant Force Springs in Medical Devices
Constant force springs provide several mechanical advantages that make them ideal for medical environments where performance, predictability, and reliability are essential:
Smooth, controlled motion. These springs deliver a uniform force shortly after the moment they begin to actuate, unlike traditional springs, which require a longer ramp-up. This smoothness is valuable in patient-facing devices and precision equipment.
Steady actuation without lag. Because the force remains constant, devices benefit from immediate responsiveness. Surgeons, clinicians, and technicians experience predictable, repeatable motion every time.
High force output in compact spaces. Constant force springs deliver strong output despite their small size. This is especially important as devices continue to be miniaturized, including handheld tools and portable or wearable medical technologies.
Reduced mechanical complexity. In some designs, constant force springs can replace motors, gas springs, or locking mechanisms. This simplification can reduce maintenance needs, lower manufacturing costs, and improve long-term reliability.
Calibration consistency. With predictable force throughout their lifespans, constant force springs support medical devices that must maintain tight tolerances. This reliability is invaluable during regulatory evaluation.
Durability under high-duty cycles. These springs are engineered for repeated use, making them well-suited for clinical environments where devices operate continuously or are frequently repositioned.
How Constant Force Springs Power Modern Devices
Imaging Equipment (MRI, CT, X-ray)
In imaging systems, constant force springs can be used to support heavy components, such as imaging heads, articulating arms, and gantries. Technicians must be able to reposition these parts smoothly and accurately to promote clear image quality and safe operation. Springs for MRI systems are often manufactured from non-magnetic materials such as Inconel or Elgiloy.
Surgical Robotic Systems
Robotic systems depend on precise, fluid movement. Constant force springs counterbalance arm segments, reducing motor load and helping the system maintain consistent tool orientation. This improves the responsiveness of robotic joints and supports the surgeon’s need for high-stability, low-resistance movement during delicate procedures.
Handheld Surgical Tools
From retractors to handheld cutters, many surgical tools rely on uniform actuation. Constant force springs provide that consistency, which gives surgeons predictable tactile feedback with every use. This helps improve accuracy, reduces user fatigue, and supports reliable operation in time-sensitive procedures.
Infusion and Drug Delivery Pumps
In drug delivery systems such as auto-injectors, insulin pumps, and infusion devices, constant force springs apply steady pressure to plungers or reservoirs. This allows for regulated, accurate dosing, which is critical for drug efficacy and patient safety.
Patient Support and Rehabilitation Equipment
Constant force springs assist in positioning hospital beds, monitor arms, surgical lights, and rehabilitation machines. They help caregivers adjust equipment with minimal effort, enhancing workflow efficiency and supporting ergonomic safety. The springs also prevent sudden drops or unsteady motion, improving patient protection during repositioning.
Wearables and Portable Devices
In exoskeletons, orthotic braces, prosthetics, and compact wearable pumps, constant force springs provide continuous support that remains consistent throughout the entire motion range. By offsetting device or limb weight, they improve comfort and reduce fatigue for long-term users.
John Evans’ Sons – Experts in Medical Device Springs
As the first spring manufacturer in the United States, John Evans’ Sons brings deep expertise to medical spring engineering. We support a wide range of applications, including imaging equipment, surgical tools, drug-delivery systems, wearables, and patient-care devices, through precision manufacturing and collaborative engineering.
At John Evans’ Sons, we continuously uphold the standards of ISO 13485: 2016. We ensure that every spring is produced under strict quality and traceability requirements. Our in-house tooling, prototyping capabilities, and custom design support help medical OEMs accelerate development and bring safe, reliable products to market.
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Celebrating Student Contributions
On July 23, 2024, Sam Davey Co-President of John Evans’ Sons LLC visited Montgomery County Intermediate Unit (MCIU) with the John Evans’ team. They took this opportunity to express their gratitude to the students for their dedicated work and discuss the impact of their contributions. John Evans’ Sons, a leading manufacturer recognized for its innovative window balance systems, is a long-time supporter of MCIU’s extended school year transition program.
The Montgomery County Intermediate Unit was established by the Pennsylvania Legislature in 1971 to aid local school districts.
MCIU Mission:
“The Montgomery County Intermediate Unit, a dynamic educational service agency, provides visionary leadership, impactful services, and strategic solutions that maximize access and opportunities for all learners.”
MCIU provides special services through cooperation and collaboration among schools and community agencies. These services result in innovative, responsive, and cost-effective programs. Offering direct and indirect support to more than two million students and nearly 147,000 school professional staff in Pennsylvania.
Extended School Year
Due to the remarkable work of MCIU, John Evans’ Sons takes pride in providing them with continuous support. The ESY program maintains and strengthens transition skills over the summer to enhance personal and social independence. Through the transition program for ESY, each student develops appropriate social skills, career acquisition skills, and career retention skills.
A Day of Recognition and Learning
A Day of Recognition and Learning
As part of MCIU’s transition program, these hardworking students have demonstrated remarkable precision and a quality-oriented mindset by assembling shoes and cams for window balance systems. At the visit, they had the opportunity to meet the people behind the products they assembled, ask questions, and discuss their experiences. The ability to assemble shoes and cams requires dedication, attention to detail, patience, and care. After transitioning from MCIU, these skills will be crucial in achieving independence, succeeding in the workplace, and fostering self-pride.
The Importance of Their Work
The John Evans’ team first shared a comprehensive overview of the significance of the students’ efforts because of the tremendous impact they have. Then, it highlighted how these components are crucial for window functionality in homes across the Caribbean to Canada. Last, members demonstrated the role of the cam, engaging and pushing the top guide of the window balance, which is then moved along with the window.
This visit wasn’t just about recognizing the students’ contributions. It was an educational experience that connected classroom knowledge with real-world applications. They learned firsthand how their work fits into a larger picture. The skills they learned assembling, working together, and independence are something they can take satisfaction in. This group showed great attention to detail and quality work, they did an amazing job they can be proud of.
A Bright Future of Collaboration
Above all, the visit from John Evans’ Sons highlighted the power of community collaboration. By working together, businesses and educational institutions can create enriching experiences that benefit both students and companies. The gratitude expressed by John Evans’ Sons underscores the importance and impact of the students’ hard work.
As the visit concluded, there was a shared excitement for future support. Both, John Evans’ Sons and MCIU, look forward to continuing their partnership, providing students with valuable opportunities to learn and grow through practical experiences.
Posted by jla on | Comments Off on Custom Springs for Fire Dampers
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.
Posted by jla on | Comments Off on Exploring Constant Force Spring Benefits for Your Application
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
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.
Constant Force Spring Benefits
Small Space Requirements
Their design allows tight coiling, making them an excellent choice for devices with limited space.
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.
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.
Versatile and easily integrated into existing hardware setups. This flexibility simplifies the design process and can reduce manufacturing time and costs.
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.
