medical team performing operation on patient

Custom Springs for the Medical Device Industry

John Evans’ Sons offers several counterbalance options to assist and/or enhance articulated instruments for medical or dental equipment design. We meet the highest quality requirements to ensure top equipment performance.

Applications include:

  • Table and bed lift mechanisms
  • Counterbalancing of computer monitors in fixed and mobile applications
  • MRI & X-ray devices
  • Dental x-ray equipment articulated arms
  • Medical equipment drawer closing mechanisms
  • Surgical staplers
  • Drug infusers and delivery systems


constant force springs mounted on plastic drums

Constant force springs offer significant benefits compared with traditional helical springs and gas springs:

Constant Force Springs provide a smooth range of motion and a constant load in either extending or retracting direction. This spring design has no inertia to overcome when considering the initial position starting forces. Constant force springs are compact and mount easily to existing hardware. Applications include counterbalancing of aircraft cargo doors, as well as interior and exterior aircraft motion control mechanisms.

  • Smooth range of motion
  • Constant load in either extending or retracting direction
  • No inertia to overcome when considering the initial position starting forces
  • Compact and mount easily to existing hardware
  • Can eliminate costly and complicated motors decreasing device size and cost


side view of spiral torsion springSpiral torsion springs

Spiral torsion springs are normally used in applications requiring less the 360 degrees of rotation. They are generally used to obtain a large amount of torque through a small amount of rotation. Spiral Torsion Springs allow for rotation in two directions and a “return to center” capability. Used in pairs at right angle to each other, a wide range of motion can be achieved in two axis configuration, while still preserving the “return to center” feature (as in a dental X-ray head unit).

  • Develops high torque
  • Rotation in two directions
  • Compact, easily mounts in many designs


reel1 copy

Spring powered reels

Spring powered reels (arbor and base mounted) are available with a wide range of forces, cable lengths, and travel. Spring powered reels mount easily, come with pre-installed cables and attach quickly.

  • Wide range of forces, cable lengths, and travel
  • Mounts quickly and easily
  • Metal and plastic available


spring and assembled components for a turn key assy.Spring and component assembly capability

Spring sub-assemblies may call for the use of components made of a variety of materials (molded plastic, machined metal, rubber). We frequently are able not only to produce the specialty spring, but then to assemble the spring and various customer designated or customer supplied additional parts into a completed sub-assembly.

Often, it is cost-effective to consider sub-assembly at the point of spring manufacture, and in this approach, John Evans’ excels.

John Evans’ has a fully staffed Engineering department that is eager to discuss the design requirements and equipment counterbalancing challenges in your design and prototype phase.

In fact, many choices of counter-balances, springs and reels are stock items and can ship quickly to aid in your product evaluation.

Medical and dental counterbalance springs

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John Evans Medical Spring Mfg
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JES Corp. Profile

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Spring Products

for Medical Designers
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Constant Force Springs

for Medical Designers
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Constant Force Selection Chart

for Medical Designers
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Enclosed Reels

for Medical Designers
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Large Reels Info

& Selection Chart for Medical Designers
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Vibration Isolator Intro

for Medical Designers

Examples of Critical Healthcare Equipment Torsion & Constant Force Springs


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Got A Question? Consult our Experts.

Our experts offer a depth of expertise to assist you with all parts of the process. We are ready to answer your questions in a timely manner and will help you define what you need. We produce custom springs for all purposes, and we are here to work with you on any of your customization needs.

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