Locking Gas Springs: How They Function and When to Use Them

Locking gas springs are specialized pneumatic struts that allow a panel or lid to be fixed at any point along its stroke, preventing movement until an external actuator is engaged. Unlike standard gas springs that provide constant force, these units feature an internal valving system that blocks flow between the cylinder chambers, effectively locking the piston rod in place.

How Do Rigid and Elastic Locking Springs Differ?

Rigid locking prevents all movement in either direction, while elastic locking allows for a slight cushion under extreme load conditions.

What Defines Rigid Locking Gas Springs?

Rigid locking gas springs use a closed valve to block oil flow, creating a fixed, non-compressible position for stable heavy loads.

Rigid units are my first choice for precision applications like monitor arms or surgery tables. When the valve closes, the rod is held firmly by the incompressible oil, preventing any “bounce” or deflection.

Engineers often prefer these for applications requiring absolute stability. If you are designing for industrial machinery, consider the weight distribution before selecting the rod diameter.

What Defines Elastic Locking Gas Springs?

Elastic locking gas springs allow a small degree of movement due to the gas compressibility, providing a safety buffer for impacts.

Elastic locking uses a gas-side lock, which allows the load to flex slightly under stress. This behavior acts as a shock absorber, protecting the hinge and mounting brackets from catastrophic failure.

These are common in mobile applications like vehicle seating or transport stretchers. If you are retrofitting equipment, verify your force calculations to ensure the spring rating matches your dynamic load requirements.

Where Are Locking Gas Springs Most Commonly Used?

Locking gas springs are critical in medical equipment, vehicle seating, industrial access hatches, and adjustable ergonomic furniture.

Why Are They Used in Medical and Care Equipment?

Medical devices require reliable, infinite position locking to ensure patient safety during adjustments on beds or imaging tables.

In clinical settings, the ability to lock a position instantly is a safety mandate. These springs ensure that equipment remains stationary while a caregiver operates the controls.

For more specific requirements on dampening and speed, refer to our end fittings guide to ensure your setup is secure. Precision is essential in every industrial or medical application.

What Are the Benefits in Industrial Machine Guarding?

Machine guards use locking struts to hold access panels open at safe angles, preventing injury during maintenance or cleaning.

Maintenance teams need both hands free when working on internal components. A locking strut eliminates the risk of an access hatch falling unexpectedly due to vibration or wind.

Ensure that your mounting points are reinforced, as the locking force can concentrate stress on the bracket. Always inspect these units annually for seal integrity.

How Should You Select a Locking Gas Spring?

Select a locking gas spring by calculating total load, stroke length, required locking force, and the activation release mechanism.

What Role Does the Release Mechanism Play?

The release mechanism, usually a button, lever, or Bowden cable, disengages the valve to allow the piston to travel freely again.

If your application has limited space, a Bowden cable is the most efficient choice for remote activation. Conversely, a simple pin-push button works well for directly accessible hatches.

How Is the Force Rating Determined?

Force rating must accommodate the full weight of the lid plus the added safety margin for dynamic loads and temperature changes.

You cannot simply guess the Newton force. Use a standard force calculation and add a 20% margin for locking units to account for the internal valving resistance during engagement.

What Materials and Environmental Ratings Should Be Considered?

Locking gas springs are available in various materials and seals to suit corrosive, hygienic, or extreme‑temperature environments.

For food‑processing, medical, or outdoor applications, choose a body made of 316 stainless steel or coated carbon steel with a nitrile or FKM seal that resists washdown chemicals and UV exposure. In high‑temperature settings (above 80 °C), select springs with high‑temp seals and a gas fill formulated to maintain pressure stability.

Additionally, look for an IP rating (e.g., IP65 or IP67) if the unit will be exposed to dust, water jets, or temporary immersion. Matching the spring’s environmental class to the machine’s operating conditions prevents premature seal failure and ensures consistent locking force over the product’s lifespan.

FAQ: Locking Gas Spring Maintenance

Can I repair a leaking locking gas spring?

No, gas springs are sealed, pressurized units that cannot be field-repaired and must be replaced as a complete assembly.

Do these springs lose force over time?

Yes, like all nitrogen-filled springs, seal wear eventually causes pressure loss, though high-quality units last for 50,000 cycles.

Are they compatible with all mounting types?

Locking springs use standard ball and socket or clevis mounts, but the release cable adds a requirement for fixed, stable housing.